JP2009097646A - Control device for variable displacement fluid pressure pump motor type transmission - Google Patents

Abstract

A control device for a variable displacement fluid pressure pump motor type transmission capable of shortening a shift time and performing a rapid shift is provided.
Control of a transmission capable of setting a fixed speed determined by a gear ratio of a gear pair and a continuously variable speed state in which power transmitted between the pump motors via pressure oil is continuously changed. In the device, the pressure accumulator that accumulates the pressure fluid and discharges the accumulated pressure fluid, the pressure accumulation state in which the pressure fluid discharged from the replenishment pump is accumulated in the pressure accumulator, and the pressure fluid accumulated in the pressure accumulator is discharged to the closed circuit A pressure accumulating control means for selectively setting a discharge state to be transmitted, and a transmission mechanism that is brought into a power transmission state when the transmission mechanism is switched from a power cutoff state to a power transmission state by a switching mechanism. Pressure accumulation control means (steps S2 to S10) for supplying pressure oil to the pump motor on the other side via the first oil passage or the second oil passage and driving the pump motor.
[Selection] Figure 4

Description

  The present invention includes at least a pair of variable displacement fluid pressure pump motors that can exchange pressure fluid with each other, at least two transmission mechanisms that transmit torque transmitted by each variable displacement fluid pressure pump motor to an output member, A switching mechanism for switching each transmission mechanism between a power transmission enabled state and a power transmission disabled state, and between the fixed speed determined by the transmission gear ratio of one of the transmission mechanisms and each variable displacement hydraulic pump motor The present invention relates to a transmission control device capable of setting a continuously variable transmission state by changing the power transmitted via pressure fluid.

  This type of transmission is described in Patent Document 1. To briefly explain the configuration, a variable displacement fluid pressure pump motor is connected to the reaction force element in each of the pair of planetary gear mechanisms, and the discharge ports and the suction ports of each fluid pressure pump motor are connected to each other. A closed circuit is formed. Moreover, the power output from a power source such as an engine is input to the input element in each planetary gear mechanism. Furthermore, a drive gear for setting a so-called fixed stage is arranged on an intermediate shaft integral with the output element of each planetary gear mechanism, and a driven gear meshing with each drive gear is arranged on the output shaft. Yes. A synchronous coupling mechanism (so-called synchro) is provided for switching each gear pair composed of the drive gear and the driven gear between a state where torque can be transmitted and a state where torque is not transmitted.

  Therefore, if one of the fluid pressure pump motors is locked and the reaction force element is fixed, the power output from the power source is transmitted to one of the intermediate shafts via the planetary gear mechanism having the reaction force element. Power is transmitted to the output shaft through a gear pair connected to the intermediate shaft by synchronization. In this case, the gear ratio is a gear ratio according to the gear ratio of the gear pair involved in power transmission.

  The lock of the fluid pressure pump motor in this case is set by making the extrusion volume of the other fluid pressure pump motor zero. That is, since each fluid pressure pump motor is connected by a closed circuit, if the extrusion volume of the other fluid pressure pump motor is reduced to zero, the flow of pressure fluid does not occur. Therefore, the extrusion volume of one fluid pressure pump motor By setting the extrusion volume to be greater than zero, such as maximizing, one hydraulic pump motor is locked and prevented from rotating.

  Further, the extrusion volume of each fluid pressure pump motor is made larger than zero, a predetermined gear pair is set in a state where torque can be transmitted by synchronization on one fluid pressure pump motor side, and synchronization on the other fluid pressure pump motor side is performed. When the other gear pairs are in a state capable of transmitting torque, a gear ratio having an intermediate value of the gear ratio determined according to the gear ratio of each gear pair is set. That is, one fluid pressure pump motor generates a pressure fluid, which is supplied to the other fluid pressure pump motor and operates as a motor, and the power is transmitted to the output shaft through the other gear pair. As a result, power that is a combination of the power transmitted through the fluid and the power mechanically transmitted through one fluid pressure pump motor appears on the output shaft. Since the power through the fluid can be continuously changed by continuously changing the extrusion volume of each fluid pressure pump motor, the transmission ratio as a whole of the transmission is continuously changed. In other words, it can be set steplessly.

  Patent Document 2 discloses a device that collects deceleration energy (inertia energy) of a vehicle and accumulates it in an accumulator, and pumps a variable displacement hydraulic pump / motor connected to an output shaft when the vehicle decelerates. An invention relating to a vehicle deceleration energy recovery device is described in which hydraulic oil pressurized by operating as an accumulator is sent to an accumulator to accumulate pressure, and a hydraulic pump motor is operated as a motor by the accumulated energy in the accumulator. Yes.

JP 2006-266493 A No. 7-8925

  In the transmission described in the above-mentioned Patent Document 1, when changing the gear ratio according to the gear ratio of any gear pair, that is, when shifting beyond or across the fixed gear (fixed gear ratio), the synchro is switched. By operating, the gear pair involved in power transmission is changed. More specifically, while maintaining the sync on the one intermediate shaft side in a so-called engaged state, the sync on the other intermediate shaft side is moved to the neutral position and moved to the other gear pair side, depending on the gear. It switches to what is called an engagement state which transmits motive power. In the process of switching, a fixed shift stage is set once, and the sync that is not involved in torque transmission in that state is switched. That is, the synchro connected to the variable displacement fluid pressure pump motor with zero extrusion volume is switched.

  Therefore, in the transmission described in Patent Document 1, when changing the gear ratio across the fixed gear, the synchro is switched while the gear ratio is at the fixed gear. Therefore, the change in the transmission gear ratio is stagnant in the state of the fixed gear stage until the sync switching operation is completed.

  That is, in the transmission described in Patent Document 1, in the case of a shift that changes the gear ratio between the fixed gear speeds determined by the gear ratio of each gear pair, the gear ratio is continuously changed. That is, continuously variable transmission is possible. However, in the case of a shift in which the gear ratio is changed across the fixed gear, it is necessary to perform the sync switching operation with the gear ratio set to the fixed gear as described above. The displacement volume of the capacitive fluid pressure pump motor must be reduced to zero, and the rotation of the rotation axis of the synchro that performs the switching must be synchronized with the rotation of the rotation member that is the switching destination. As a result, the continuous change of the gear ratio is temporarily stagnated until the shifting operation of the synchro is completed and the extrusion volume of the variable displacement fluid pressure pump motor is increased again, and the speed change time becomes longer. turn into.

  Increasing the synchro capacity can reduce the time required to synchronize the rotation of the synchro, but in this case, the synchro physique will increase as the capacity increases, and the transmission physique will eventually increase. It becomes necessary to enlarge. As described above, in the transmission described in Patent Document 1, there is still room for improvement in order to reduce the synchronization switching time and perform a quick shift without increasing the size of the transmission. .

  The present invention has been made paying attention to the technical problem described above, and in a transmission using a variable displacement fluid pressure pump motor, the transmission can be changed with a switching operation of a switching mechanism without increasing the size of the transmission. Even if it exists, it aims at providing the control apparatus which can shorten speed change time and can perform a quick speed change.

  In order to achieve the above object, the first aspect of the present invention provides a first power transmission path and a second power transmission path capable of selectively setting a plurality of different gear ratios between the power source and the output member. And the torque transmitted through each of these power transmission paths is provided for each of the power transmission paths so as to change according to the extrusion volume, and when one of the extrusion volumes is zero, the other is a pressure fluid. A variable displacement first fluid pressure pump motor and a second fluid pressure pump motor in which suction ports and discharge ports are connected to each other via a closed circuit so that supply and discharge are blocked and locked; A first transmission mechanism that is disposed in the first power transmission path together with one fluid pressure pump motor and that transmits power from the power source to the output member when the first fluid pressure pump motor is locked; 2 A second transmission mechanism disposed in the second power transmission path together with the body pressure pump motor and transmitting power from the power source to the output member when the second fluid pressure pump motor is locked; A switching mechanism that selectively switches the power transmission mechanism between a power transmission state in which power can be transmitted to the output member and a power cut-off state in which power transmission is impossible; and a replenishment pump that supplies pressure fluid to the closed circuit; A continuously variable transmission state by continuously changing the fixed transmission stage determined by the transmission ratio of each of the transmission mechanisms and the power transmitted through the pressure fluid between the fluid pressure pump motors. In a control device for a variable displacement fluid pressure pump motor type transmission configured to be able to set the pressure, a pressure accumulating device capable of accumulating pressure fluid and discharging the accumulated pressure fluid, The pressure accumulation device and the closed circuit are shut off, the supply pump and the closed circuit are shut off, and the pressure fluid discharged from the supply pump through the supply pump and the pressure accumulation device is communicated to the pressure accumulation device. The pressure fluid accumulated in the pressure accumulating device is communicated with the pressure accumulating state for accumulating and the first oil passage connecting the suction ports of the pressure accumulating device and the closed circuit or the second oil passage connecting the discharge ports with each other. A pressure accumulation control means for selectively setting a discharge state to be discharged into a closed circuit, and when performing a shift with an operation of switching any of the transmission mechanisms from the power cut-off state to the power transmission state by the switching mechanism, The accumulation state is set in the fluid pressure pump motor on the power transmission path side where any one of the transmission mechanisms that set the discharge state by the pressure accumulation control means and set the power transmission state is arranged. And a shift control means for supplying the pressurized pressure fluid to drive the fluid pressure pump motor.

  According to a second aspect of the present invention, in the first aspect of the invention, the first transmission mechanism and the second transmission mechanism are respectively connected to a rotor of the first fluid pressure pump motor and a rotor of the second fluid pressure pump motor. Rotating shafts connected to each other, a transmission rotator that is rotatably fitted to the respective rotation shafts and transmits power to the output member by being connected to the rotation shafts, and the respective transmission rotators. A plurality of gear pairs connected to each other and having different gear ratios, wherein the switching mechanism moves the sleeve in the axial direction of the rotary shaft to engage with the transmission rotary member, thereby rotating the rotary shaft and the transmission rotary member. A synchronous coupling mechanism that achieves the power transmission state by connecting the transmission shaft to the transmission rotating body and the transmission shaft. A control device which comprises a means for driving the fluid pressure pump motors in the direction of promoting translocation synchronization.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the shift control means supplies the accumulated pressure fluid to any one of the fluid pressure pump motors via the first oil passage. The rotational speed of the fluid pressure pump motor is increased in the same positive rotation direction as the rotation direction of the power source, and the accumulated pressure fluid is supplied to any one of the fluid pressures via the second oil passage. A control device comprising means for increasing the rotational speed of the fluid pressure pump motor in a reverse rotation direction opposite to the rotation direction of the power source by supplying the pump motor to the pump motor.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the pressure accumulation control means is predetermined so that the pressure accumulation of the pressure accumulator is maintained at a desired pressure level. And a means for increasing the discharge pressure of the replenishment pump and setting the pressure accumulation state and accumulating the pressure fluid discharged from the replenishment pump in the pressure accumulator when the pressure becomes less than the predetermined pressure. It is a control device.

  According to the first aspect of the present invention, when accumulating the pressure fluid to the accumulator, the closed circuit, the accumulator and the supplement pump are shut off, and the supplement pump and the accumulator are communicated and discharged by the supplement pump. The pressurized fluid is accumulated in the accumulator. Therefore, when accumulating pressure fluid in the accumulator, the pressure fluctuation caused by discharging the pressure fluid supplied to the accumulator by the replenishment pump is not affected on the closed circuit, and the pressure of the pressure fluid in the closed circuit is reduced. While maintaining a stable state, the pressure fluid can be quickly accumulated in the accumulator by the replenishment pump.

  On the other hand, when changing the gear ratio across the fixed gear positions, that is, when executing a shift operation that switches one of the switching mechanisms from the power cutoff state to the power transmission state, the pressure accumulator and the closed circuit The first fluid passage or the second fluid passage is communicated, and the pressure fluid accumulated in the pressure accumulator is supplied to the fluid pressure pump motor on the side where the switching mechanism for switching operation is arranged. Therefore, the fluid pressure pump motor is driven in the forward rotation direction or the reverse rotation direction, and the rotation number of the rotation member of the fluid pressure pump motor, that is, the switching mechanism connected to the fluid pressure pump motor can be controlled. As a result, the switching mechanism can be switched quickly. For this reason, even in a shift that changes the gear ratio across the fixed shift stages, the shift time can be shortened and a quick and smooth shift can be executed.

  According to the second aspect of the present invention, when changing the gear ratio across the fixed gear, that is, when performing a shift with a switching operation of one of the switching mechanisms, in other words, the sleeve of the synchronous coupling mechanism Are connected so as to rotate integrally or differentially with the rotating shaft to be connected, that is, the rotor of the fluid pressure pump motor, when shifting is performed with the movement of connecting the rotating shaft and the transmission rotating body. In a direction to synchronize the rotation of the rotating shaft and the rotation of the transmission rotating body connected via the gear pair that sets the fixed gear stage of the transmission gear ratio before and after the fixed gear stage spanning the output member, The fluid pressure pump motor is driven. Therefore, the rotation synchronization between the rotating shaft and the transmission rotating body can be promoted, and the time required for the movement of the sleeve of the synchronous coupling mechanism, that is, the switching operation of the switching mechanism can be shortened. Even if the shift is performed across steps, the shift time can be shortened and a quick and smooth shift can be executed.

  Further, according to the invention of claim 3, the pressure accumulator includes a first oil passage that communicates the suction ports of the fluid pressure pump motors, and a second oil passage that communicates the discharge ports of the fluid pressure pump motors. Are selectively communicated with each other to discharge the accumulated pressure fluid. Therefore, by shutting off one of the fluid pressure pump motors and the closed circuit, communicating the pressure accumulating device and the first oil passage, discharging the accumulated pressure fluid, and supplying it to the other fluid pressure pump motor. The other fluid pressure pump motor is driven in the forward rotation direction, and conversely, the pressure accumulating device and the second oil passage are communicated, and the accumulated pressure fluid is discharged and supplied to the other fluid pressure pump motor. The other fluid pressure pump motor can be driven in the reverse rotation direction. Therefore, when performing a shift with a switching operation of the switching mechanism, the fluid pressure pump motor on the side where the switching mechanism that performs the switching operation is driven in the forward rotation direction or the reverse rotation direction, that is, the fluid pressure pump The number of rotations of the motor can be controlled.

  According to the fourth aspect of the present invention, pressure accumulation of the pressure fluid in the pressure accumulator is performed only when the pressure fluid in the pressure accumulator decreases and the pressure accumulation becomes lower than a predetermined pressure. Therefore, when accumulating pressure fluid in the accumulator, pressure fluctuation in the closed circuit due to the supply pump and the closed circuit being cut off can be minimized.

  Next, the present invention will be described based on specific examples. First, the transmission that is the subject of the present invention will be described. The transmission that is the subject of the present invention includes at least two power transmission paths, and the output member from the power source via both power transmission paths. Thus, the transmission can continuously change the speed ratio, which is the ratio of the rotational speeds of the power source and the output member.

  More specifically, each of the power transmission paths described above includes a variable displacement fluid pressure pump motor that functions as a pump and a motor, respectively, and a torque corresponding to the extrusion volume of the variable displacement fluid pressure pump motor. In addition, the variable displacement fluid pressure pump motors communicate with each other so as to exchange pressure fluids. Therefore, when one of the variable displacement fluid pressure pump motors functions as a pump, torque corresponding to the extrusion volume is transmitted from the power source to the output member, and at the same time, from one variable displacement fluid pressure pump motor to the other. Pressure fluid is supplied to the variable displacement fluid pressure pump motor, and the other variable displacement fluid pressure pump motor functions as a motor. That is, power transmission via the pressure fluid is performed in parallel. The torque is transmitted to the output member via the other power transmission path. As a result, the torque transmitted to the output member is the sum of the torque transmitted through each power transmission path, and the torque transmitted through the pressure fluid changes according to each extrusion volume. Eventually, the gear ratio changes continuously.

  Each power transmission path can be provided with a transmission mechanism such as a gear pair or a winding transmission mechanism with different speed ratios, and when transmitting torque to the output member via only one power transmission path, the transmission The overall gear ratio is determined by the gear ratio of the transmission mechanism in the power transmission path. If such a gear ratio is referred to as a fixed gear ratio (or a fixed gear), power transmission via pressure fluid does not occur in a state where the fixed gear ratio is set, so that power loss is unlikely to occur. It becomes an efficient transmission state. Note that a switching mechanism such as a clutch mechanism is preferably included in each transmission mechanism so that only one of the transmission mechanisms is involved in torque transmission, or between the power source or output member and the transmission mechanism. It is preferable to provide a switching mechanism.

  Since the transmission targeted by this invention is configured to transmit power via pressure fluid, it may be a transmission configured as a hydrostatic transmission (HST), but as described above. It is preferably configured as a hydrostatic mechanical transmission (HMT) having a function of setting a gear ratio by mechanical power transmission. The mechanical transmission portion can be appropriately configured as necessary. A mechanism in which a gear pair that is always meshed is selected by a clutch mechanism or a synchronous coupling mechanism, or a plurality of planetary gear mechanisms or compound planets. A configuration in which a plurality of gear ratios can be set by a gear mechanism can be employed. Further, the variable displacement fluid pressure pump motor may be configured to use a variable displacement fluid pressure pump motor as the reaction force means, in addition to the structure in which the variable displacement fluid pressure pump motor is interposed in series between the power source and the output member.

  FIG. 1 shows an example of a transmission targeted by the present invention. This is an example configured as a transmission for a vehicle, and four forward speeds and one reverse speed are set as a so-called fixed speed ratio (fixed speed) that can be set by transmitting torque without passing through a fluid. This is a configured example. That is, in the transmission TM that is the object of the present invention mounted on a vehicle, the input member 2 is connected to the power source (E / G) 1, and torque is transmitted from the input member 2 to the differential mechanism. It is configured. As the differential mechanism, various types of conventionally known structures can be adopted. In the example shown in FIG. 1, the first planetary gear mechanism 3 (that is, the first power split mechanism) and the second planetary gear are used. Mechanism 4 (that is, the second power split mechanism) is employed.

  The power source 1 may be a general power source used in a vehicle such as an internal combustion engine, an electric motor, or a combination of these. In the following description, an example in which an engine 1 such as a gasoline engine, a diesel engine, or an LPG engine is used as the power source 1 will be described. Moreover, you may interpose suitable transmission means, such as a damper, a clutch, and a torque converter, between this engine 1 and the input member 2.

  The first planetary gear mechanism 3 is disposed on the same axis as the input member 2, the second planetary gear mechanism 4 is separated outward in the radial direction of the first planetary gear mechanism 3, and the respective central axes are parallel to each other. They are arranged in parallel. As each of these planetary gear mechanisms 3 and 4, an appropriate type of planetary gear mechanism such as a single pinion type or a double pinion type can be adopted. The example shown in FIG. 1 is an example constituted by a single pinion type planetary gear mechanism, and is a sun gear 3S, 4S that is an external gear, and a ring gear 3R that is an internal gear arranged concentrically with the sun gear 3S, 4S. , 4R and carriers 3C, 4C holding pinion gears meshed with these sun gears 3S, 4S and ring gears 3R, 4R so as to be rotatable and revolved. The input member 2 is connected to the ring gear 3R in the first planetary gear mechanism 3, and the ring gear 3R serves as an input element.

  Further, a counter drive gear 5 is attached to the input member 2, and an idle gear 6 is engaged with the counter drive gear 5, and a counter driven gear 7 is engaged with the idle gear 6. The counter driven gear 7 is arranged on the same axis as the second planetary gear mechanism 4 and is connected to the ring gear 4R of the second planetary gear mechanism 4 so as to rotate together. Therefore, in the second planetary gear mechanism 4, the ring gear 4R serves as an input element. The ring gears 3R and 4R, which are input elements of the planetary gear mechanisms 3 and 4, are configured so that the counter gear pair includes the idle gear 6, and thus rotate in the same direction.

  The carrier 3C in the first planetary gear mechanism 3 serves as an output element, and a first intermediate shaft 8 corresponding to the rotating shaft of the present invention is coupled to the carrier 3C so as to rotate together. The first intermediate shaft 8 is a hollow shaft into which a motor shaft 9 is rotatably inserted. One end of the motor shaft 9 is a sun gear that is a reaction force element in the first planetary gear mechanism 3. It is connected to 3S so as to rotate together.

  The second planetary gear mechanism 4 has the same configuration, and the carrier 4C serves as an output element, and the second intermediate shaft 10 corresponding to the rotating shaft of the present invention is integrally rotated with the carrier 4C. To be connected. The second intermediate shaft 10 is a hollow shaft into which a motor shaft 11 is rotatably inserted. One end of the motor shaft 11 is a sun gear that is a reaction force element in the second planetary gear mechanism 4. 4S is connected to rotate integrally.

  The other end of the motor shaft 9 is connected to the output shaft (rotor shaft) of the variable displacement fluid pressure pump motor 12. The variable displacement fluid pressure pump motor 12 is an example of a hydraulic pump capable of changing the discharge capacity, such as a slant shaft pump, a swash plate pump, or a radial piston pump, and rotates the output shaft by applying torque. Therefore, the pressure fluid (pressure oil) is discharged by functioning as a pump, and the pressure fluid is supplied from the discharge port or the suction port, thereby functioning as a motor. In the following description, the variable displacement fluid pressure pump motor 12 is referred to as a first pump motor 12 and is represented as PM1 in the drawing.

  The other end of the motor shaft 11 is connected to the output shaft (rotor shaft) of the variable displacement fluid pressure pump motor 13. The variable displacement fluid pressure pump motor 13 is an example of a hydraulic pump capable of changing the discharge capacity, such as a slant shaft pump, a swash plate pump, or a radial piston pump, similar to the first pump motor. By rotating and applying torque, the pressure fluid (pressure oil) is discharged by functioning as a pump, and the pressure fluid is supplied from the discharge port or suction port to function as a motor. In the following description, the variable displacement fluid pressure pump motor 13 is referred to as a second pump motor 13 and is indicated as PM2 in the drawing.

  The pump motors 12 and 13 are communicated with each other by oil passages 14 and 15 so that the pressure oil, which is a pressure fluid, can be transferred to each other. That is, the suction ports 12S and 13S are communicated with each other by an oil passage 14 corresponding to the first oil passage of the present invention, and the discharge ports 12D and 13D are oil passages corresponding to the second oil passage of the present invention. 15 is communicated. Therefore, a closed circuit CC is formed by the oil passages 14 and 15. The suction ports 12S and 13S in the pump motors 12 and 13 are ports for sucking fluids such as oil when the pump motors 12 and 13 rotate in the same direction as the engine 1, and the discharge ports 12D and 12S. 13D is a port for discharging fluid such as oil during forward rotation. A mechanism for hydraulic control in the closed circuit CC will be described later.

  An output shaft 16 corresponding to the output member of the present invention is arranged in parallel with each of the intermediate shafts 8 and 10 described above. A transmission mechanism for setting a predetermined gear ratio is provided between the output shaft 16 and each of the intermediate shafts 8 and 10. The transmission mechanism in the present invention is not limited to a mechanism that transmits power at a fixed gear ratio, and a mechanism with a variable gear ratio can be adopted. In the example shown in FIG. 1, power is transmitted at a fixed gear ratio. A plurality of gear pairs 17, 18, 19, and 20 for transmitting the above are employed.

  More specifically, the first intermediate shaft 8 includes, in order from the first planetary gear mechanism 3 side, the fourth speed gear pair 17 and the fourth speed gear pair 18 corresponding to the first transmission mechanism of the present invention. A high-speed drive gear 17A and a second-speed drive gear 18A are disposed, and the fourth-speed drive gear 17A and the second-speed drive gear 18A are rotatably fitted to the first intermediate shaft 8. A fourth speed driven gear 17B meshed with the fourth speed drive gear 17A and a second speed driven gear 18B meshed with the second speed drive gear 18A are attached to the output shaft 16 so as to rotate integrally. Yes.

  Furthermore, the third speed drive gear 19A and the first speed drive gear 20A in the third speed gear pair 19 and the first speed gear pair 20 corresponding to the second transmission mechanism of the present invention are respectively connected to the fourth speed driven gear. It meshes with the gear 17B and the second speed driven gear 18B, and is rotatably fitted to the second intermediate shaft 10. Accordingly, the fourth speed driven gear 17B also serves as the third speed driven gear 19B, and the second speed driven gear 18B also serves as the first speed driven gear 20B. Here, the gear ratio of each gear pair 17, 18, 19, and 20 (ratio of the number of teeth of the driven gear to the number of teeth of each drive gear) will be described. The second speed gear pair 18, the third speed gear pair 19, and the fourth speed gear pair 17 are configured to decrease in order.

  Furthermore, a starting gear pair 21 is provided. The starting gear pair 21 is for transmitting the power to the output shaft 16 together with the first speed gear pair 20 so as to increase the driving force at the time of starting sufficiently and sufficiently. A start drive gear 21 </ b> A attached to rotate integrally with the motor shaft 9 on the motor 12 side and a start driven gear 21 </ b> B attached to the output shaft 16 so as to be rotatable are provided.

  Each of the gear pairs 17, 18, 19, 20, and 21 described above is configured to selectively transmit torque between any of the intermediate shafts 8 and 10 and the output shaft 16, that is, each gear pair. 17, 18, 19, 20, and 21 are selectively set to a power transmission state in which power can be transmitted between any one of the intermediate shafts 8 and 10 and the output shaft 16 and a power cutoff state in which power transmission is impossible. A clutch mechanism corresponding to the switching mechanism of the present invention for switching is provided. In short, this clutch mechanism is a mechanism that selectively transmits torque, and employs a conventionally known mechanism such as a dog clutch mechanism, a synchronous coupling mechanism (synchronizer), and a friction engagement mechanism such as a friction clutch. FIG. 1 shows an example employing a synchronizer.

  The synchronizer basically moves the sleeve that rotates together with the rotating shaft in the axial direction, and engages with the spline of the rotating member that is mounted so as to rotate relative to the rotating shaft. When the kniter ring is gradually brought into frictional contact with the rotating member, the rotating shaft and the rotating member are synchronized to connect the rotating shaft and the rotating member. On the output shaft 16, a first synchronizer (hereinafter referred to as a first synchronizer) 22 is provided at a position adjacent to the starter driven gear 21B. The first sync 22 moves its sleeve to the left side of FIG. 1 to connect the starter driven gear 21B to the output shaft 16, and the starter gear pair 21 torques between the motor shaft 9 and the output shaft 16. Is configured to communicate.

  Further, on the second intermediate shaft 10, a second synchronizer (hereinafter referred to as a second synchronizer) 23 is provided between the third speed drive gear 19A and the first speed drive gear 20A. The second synchronizer 23 connects the first speed drive gear 20A to the second intermediate shaft 10 by moving the sleeve to the left side in FIG. 1, and the first speed gear pair 20 is connected to the second intermediate shaft 10. Torque is transmitted to and from the output shaft 16. On the other hand, the third speed drive gear 19A is connected to the second intermediate shaft 10 by moving the sleeve to the right in FIG. 1, and the third speed gear pair 19 is connected to the second intermediate shaft 10 and the output shaft 16. Torque is transmitted between the two.

  Further, on the first intermediate shaft 8, a third synchronizer (hereinafter referred to as a third synchronizer) 24 is provided between the second speed drive gear 18A and the fourth speed drive gear 17A. The third synchronizer 24 moves the sleeve to the left side in FIG. 1 to connect the second speed drive gear 18A to the first intermediate shaft 8, and the second speed gear pair 18 is connected to the first intermediate shaft 8. Torque is transmitted to and from the output shaft 16. On the other hand, the fourth speed drive gear 17A is connected to the first intermediate shaft 8 by moving the sleeve to the right in FIG. 1, and the fourth speed gear pair 17 is connected to the first intermediate shaft 8 and the output shaft 16. Torque is transmitted between the two.

  Further, on the motor shaft 11 on the second pump motor 13 side, a reverse synchronizer (hereinafter referred to as R synchro) 25 is provided at a position adjacent to the shaft end of the second intermediate shaft 10. The R synchro 25 connects the motor shaft 11 and the second intermediate shaft 10, that is, the sun gear 4S and the carrier 4C in the second planetary gear mechanism 4 by moving the sleeve to the right in FIG. The entire planetary gear mechanism 4 is configured to rotate integrally.

  Each of the synchros 22, 23, 24, and 25 can be configured to be switched by manual operation, but can be configured to perform so-called automatic control instead. In that case, for example, an appropriate actuator (not shown) for moving the above-described sleeve in the axial direction may be provided, and the actuator may be electrically controlled.

  As described above, the transmission TM shown in FIG. 1 is configured such that the torque output from the engine 1 is transmitted to the output shaft 16 via any one of the intermediate shafts 8 and 10 or the motor shafts 9 and 11. Yes. That is, a power transmission path corresponding to the first power transmission path of the present invention from the engine 1 via the first intermediate shaft 8 or the motor shaft 9 to the output shaft 16, and the second intermediate shaft 10 or the motor from the engine 1 A plurality of gear ratios different from each other between the engine 1 and the output shaft 16 with respect to the power transmission path corresponding to the second power transmission path of the present invention that reaches the output shaft 16 via the shaft 11 are set to each synchro. Two power transmission paths that can be selectively set by switching operation of 22, 23, 24, and 25 are configured. A differential 27 is connected to the output shaft 16 through a transmission means 26 such as a gear mechanism or a winding transmission device such as a chain, from which power is output to the left and right axles 28.

  Further, a sensor for detecting the operating state of the transmission TM is provided. Specifically, the input rotational speed sensor 29 for detecting the rotational speed of the input member 2 or the counter drive gear 5 integrated therewith, the output rotational speed sensor 30 for detecting the rotational speed of the axle 28, and the first pump motor 12. A rotation speed sensor 31 for detecting the rotation speed of the second pump motor 13 and the rotation speed sensor 32 for detecting the rotation speed of the second pump motor 13 are provided.

  Next, a fluid pressure circuit (hydraulic circuit) for controlling the pump motors 12 and 13 will be described. A charge pump (or boost pump) 33 for replenishing fluid (specifically oil), which corresponds to the replenishment pump of the present invention, is provided in the above-described closed circuit CC in which the pump motors 12 and 13 are communicated. Is provided. The charge pump 33 is for compensating for the shortage of oil due to leakage from the closed circuit CC. The charge pump 33 is driven by the engine 1 or a motor (not shown) to pump oil from the oil pan 34. It supplies to the closed circuit CC.

  Therefore, the discharge port 33D of the charge pump 33 is communicated with the closed circuit CC via the later-described fourth switching valve 49 and the check valve 35. Specifically, the discharge port 33D of the charge pump 33 communicates with the oil passage 14 and the oil passage 15 in the closed circuit CC via the fourth switching valve 49, the check valve 35, and the check valves 36 and 37, respectively. Has been. That is, the fourth switching valve 49 and the check valve 35 are provided between the branch point A where the charge pump 33 communicates with the oil passage 14 and the oil passage 15 and the discharge port 33D of the charge pump 33. A check valve 36 is provided between the branch point A and the oil passage 14, and a check valve 37 is provided between the branch point A and the oil passage 15. The check valves 35, 36, and 37 are configured to open in the discharge direction from the charge pump 33 and to close in the opposite direction.

  Furthermore, a relief valve 38 for adjusting the discharge pressure of the charge pump 33 is communicated with the discharge port 33D of the charge pump 33. The relief valve 38 opens the drain port and discharges oil to the oil pan 34 when a pressure higher than the sum of the elastic force of the spring and the pilot pressure or the pressing force of the solenoid (hereinafter referred to as pilot pressure) Psol5 is applied. Accordingly, the discharge pressure of the charge pump 33 is set to a pressure corresponding to the pilot pressure Psol5.

  Between the one check valve 36 and the oil passage 14 communicated with the discharge port 33D of the charge pump 33, the check valve 36 and the oil passage 14 are in communication with each other, and the check valve 36 and the oil passage 14 And a first switching valve 39 that switches the oil passage 14 to a state in which the oil passage 14 communicates with the oil pan 34 is provided.

  The first switching valve 39 is in an ON state in which a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol3 acts so as to oppose an elastic force by a spring. The oil passage 14 is blocked, and the oil passage 14 is communicated with an oil pan 34 (that is, a drain). On the other hand, the state where the pilot pressure Psol3 is not acting is the OFF state, and the check valve 36 and the oil passage 14 are communicated. Further, a check valve 40 that opens in the direction of discharging oil toward the oil pan 34 is communicated with the drain port of the first switching valve 39. The check valve 40 has a structure in which the valve body is pressed in a closing direction by an elastic force, and therefore the drain pressure is maintained at a pressure corresponding to the elastic force.

  Further, between the other check valve 37 communicated with the discharge port 33D of the charge pump 33 and the oil passage 15, the check valve 37 and the oil passage 15 are communicated with each other, There is provided a second switching valve 41 that shuts off the passage 15 and switches the oil passage 15 to a state of communicating with the oil pan 34.

  The second switching valve 41 is in an ON state in which a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol4 acts so as to oppose an elastic force by a spring. The oil passage 15 is blocked, and the oil passage 15 is communicated with the oil pan 34 (that is, the drain). On the other hand, the state where the pilot pressure Psol4 is not acting is the OFF state, and the check valve 37 and the oil passage 15 are communicated with each other. Further, a check valve 42 that opens in the direction of discharging oil toward the oil pan 34 is communicated with the drain port of the second switching valve 41. The check valve 42 has a structure in which the valve body is pressed in a closing direction by an elastic force, and therefore the drain pressure is maintained at a pressure corresponding to the elastic force.

  The oil passage 14 further includes a first lock valve 43 that shuts off the first pump motor 12 from the closed circuit CC, and a second lock valve 44 that shuts off the second pump motor 13 from the closed circuit CC. Is provided. That is, the first lock valve 43 is provided on the first pump motor 12 side from the branch point B where the first switching valve 39 is communicated in the oil passage 14, and the second lock motor 43 is provided on the second pump motor 13 side from the branch point B. A lock valve 44 is provided.

  The first lock valve 43 is an open / close valve (on / off valve) that is switched by a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol1, and in an ON state in which the pilot pressure Psol1 is applied. The first pump motor 12 is shut off from the closed circuit CC in the closed state. On the other hand, in the OFF state where the pilot pressure Psol1 is not applied, the first pump motor 12 is communicated with the closed circuit CC in an open state.

  The second lock valve 44 is an open / close valve (on / off valve) that is switched by a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol2, and is turned on by the pilot pressure Psol2. In this state, the second pump motor 13 is shut off from the closed circuit CC in a closed state. On the other hand, in the OFF state where the pilot pressure Psol2 is not acting, the second pump motor 13 is brought into communication with the closed circuit CC in an open state.

  Since the first switching valve 39 communicates with the oil passage 14 between the lock valves 43, 44, one of the lock valves 43, 44 is turned on, and the other lock valve 44, By turning off 43, one of the pump motors 12 and 13 is locked, that is, the rotation of the output shaft (rotor) of one of the pump motors 12 and 13 is stopped and the other pump motor 13 and 12 is stopped. Is communicated with the first switching valve 39.

  When the first lock valve 43 is turned on and the first pump motor 12 is shut off from the closed circuit CC, the pressure oil discharged from the charge pump 33 is supplied to the second pump motor 13. Therefore, when the 1st lock valve 43 is an ON state, one of the 1st switching valves 39 and 41 is set to an ON state. On the other hand, when the second lock valve 44 is turned on and the second pump motor 13 is shut off from the closed circuit CC, the pressure oil discharged from the charge pump 33 is supplied to the first pump motor 12. Therefore, when the second lock valve 44 is in the ON state, any one of the switching valves 39 and 41 is set in the ON state.

  Therefore, the pilot pressures Psol1 and Psol2 for turning on the respective lock valves 43 and 44 can be diverted from the pilot pressures Psol3 and Psol4 for turning on any of the switching valves 39 and 41. The drive means (for example, a solenoid valve, a switching valve or an on-off valve) that outputs the pilot pressures Psol1, Psol2, Psol3, and Psol4 can be shared to reduce the number of parts, reduce the cost, or simplify the configuration.

  Further, an accumulator 45 is provided for accumulating pressure oil and supplying the accumulated pressure oil to the first pump motor 12 or the second pump motor 13. The accumulator 45 is a pressure accumulator for storing the hydraulic pressure generated by the charge pump 33. The accumulator 45 is mainly a cylinder (or tank) capable of enclosing the pressure oil, and the internal volume is elastically reduced as necessary to reduce the internal pressure. For example, a gas having a predetermined pressure is enclosed. The accumulator 45 is connected to the branch point A of the closed circuit CC, that is, the oil passage 14 or the oil passage 15 by the discharge oil passage 47, and branches from the accumulator 45 in the middle of the discharge oil passage 47, that is, the discharge oil passage 47. Between the location A, the 3rd switching valve 46 which switches the state which connected the discharge oil path 47 to the state interrupted | blocked is provided.

  The third switching valve 46 is an open / close valve (on / off valve) that is switched by a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol6, and in an ON state in which the pilot pressure Psol6 is applied. In an open state, the discharge oil passage 47 communicates, that is, the accumulator 45 communicates with the discharge port 33D of the charge pump 33. On the other hand, in the OFF state where the pilot pressure Psol6 is not applied, the valve is closed, and the discharge oil passage 47 is shut off, that is, the accumulator 45 is shut off from the discharge port 33D of the charge pump 33. Yes.

  A pressure accumulating oil passage 48 is provided between the accumulator 45 and the charge pump 33 in parallel with the discharge oil passage 47. The pressure accumulating oil passage 48 and the check valve 35 and the charge pump 33 are connected to each other. Between the discharge port 33D, the discharge port 33D of the charge pump 33 and the check valve 35 are shut off and the discharge port 33D of the charge pump 33 communicates with the pressure accumulation oil passage 48, and the discharge port 33D of the charge pump 33 And a pressure change oil passage 48 are provided, and a fourth switching valve 49 that switches the discharge port 33D of the charge pump 33 to a state in which the discharge port 33D communicates with the check valve 35 is provided. Note that only the flow of pressure oil from the discharge port 33D of the charge pump 33 toward the accumulator 45 is caused in the middle of the pressure accumulation oil path 48, that is, between the accumulator 45 and the fourth switching valve 49 in the pressure accumulation oil path 48. A permissible check valve 50 and a pressure sensor 51 for detecting the pressure of the pressure oil stored in the accumulator 45 and outputting a signal are provided.

  The fourth switching valve 49 is an open / close valve (on / off valve) that is switched by a pilot pressure or a pressing force by a solenoid (hereinafter referred to as a pilot pressure) Psol7, and in an ON state in which the pilot pressure Psol7 is applied. The discharge port 33 </ b> D of the charge pump 33 and the check valve 35 are blocked, and the discharge port 33 </ b> D of the charge pump 33 is communicated with the pressure accumulation oil passage 48. In other words, in the ON state, the fourth switching valve 49 shuts off between the discharge port 33D of the charge pump 33 and the closed circuit CC and between the discharge port 33D of the charge pump 33 and the discharge oil passage 47, and is charged. The discharge port 33 </ b> D of the pump 33 is communicated with the pressure accumulation oil passage 48.

  On the other hand, in the OFF state where the pilot pressure Psol7 is not acting, the discharge port 33D of the charge pump 33 and the pressure accumulation oil passage 48 are blocked, and the discharge port 33D of the charge pump 33 is communicated with the check valve 35. It has become. In other words, in the OFF state, the fourth switching valve 49 shuts off between the discharge port 33D of the charge pump 33 and the pressure accumulation oil passage 48, and closes the discharge port 33D of the charge pump 33 with the closed circuit CC and the discharge oil passage 47. It has come to communicate with.

  Accordingly, the third switching valve 46 is turned off, that is, closed, and the discharge oil passage 47 is shut off, and the fourth switching valve 49 is turned on to shut off the discharge port 33D of the charge pump 33 and the discharge oil passage 47, and By connecting the discharge port 33 </ b> D of the charge pump 33 to the pressure accumulation oil passage 48, the pressure oil discharged by the charge pump 33 can be circulated to the accumulator 45 and the hydraulic pressure can be stored in the accumulator 45. Then, the third switching valve 46 is turned on, that is, opened, and the discharge oil passage 47 is brought into communication between the accumulator 45 and the branch point A, whereby the pressure oil accumulated in the accumulator 45 passes through the branch point A. The oil passage 14 or the oil passage 15 can be circulated.

  The pumping volumes of the pump motors 12, 13 and the operations of the synchros 22, 23, 24, 25, the pilot pressures Psol3, Psol4, Psol6 of the switching valves 39, 41, 46 and the lock valves 42, 43, respectively. , Psol1, Psol2, etc. are configured to be electrically controllable, and an electronic control unit (ECU) 52 for this purpose is provided. The electronic control unit 53 is configured mainly with a microcomputer, and receives the number of rotations of a predetermined rotating member, the detection signal of the stroke switch 52 described above, or other detection signals. An operation is performed based on the input signal, information stored in advance and a program, and a command signal is output according to the operation result.

  Next, the operation of the transmission TM shown in FIG. 1 described above will be described including the control during the shift operation. In the neutral state, each synchro 22, 23, 24, 25 is controlled to a neutral position, and each sleeve has not moved to any gear pair or hub side. That is, the switching mechanism (clutch mechanism) is in a released state. Further, no pilot pressure is output, and the lock valves 43 and 44 and the switching valves 39, 41, and 46 are in the 0FF state. Furthermore, the extrusion volume of each pump motor 12, 13 is set to zero. This state is shown in FIG. 2 and the subsequent drawings, the arrows indicate the flow direction of pressure oil, the rotational direction of the shaft, or the moving direction of the synchro sleeve, and the engine 1 and the electronic control unit 52 are omitted.

  If the engine 1 is operating even in the neutral state, the charge pump 33 is driven to discharge the pressure oil. The pressure oil is supplied to the discharge ports 12D and 13D side of the pump motors 12 and 13 through the oil passage 15, but the pump volumes of the pump motors 12 and 13 are set to zero. The pressure oil does not flow through the motors 12 and 13, and the pressure oil is held by the pump motors 12 and 13. That is, each pump motor 12 and 13 maintains a stop state.

  Therefore, the alignment chart for the planetary gear mechanisms 3 and 4 is as shown in FIG. Briefly, the ring gears 3R and 4R of the planetary gear mechanisms 3 and 4 rotate forward when torque is transmitted from the engine 1, but since the sun gears 3S and 4S are stopped, the carriers 3C and 4C The planetary gear mechanisms 3 and 4 rotate forward at a rotational speed corresponding to the gear ratio (ratio between the number of teeth of the sun gear and the number of teeth of the ring gear).

  Next, the operation until the start state (or the start standby state) for starting in the forward direction from the neutral state is set will be described. In order to start in the forward direction from the neutral state, the starting gear pair 21 and the first speed gear pair 20 are set to a state in which torque can be transmitted between the intermediate shafts 8 and 10 and the output shaft 16. Specifically, the first driven gear 21 </ b> B is connected to the output shaft 16 by the first synchro 22, and the first speed drive gear 20 </ b> A is connected to the second intermediate shaft 10 by the second synchro 23. When the synchros 22 and 23 are switched to the engaged state in this way, the first speed drive gear 20A and the second intermediate shaft 10 that are connected to each other by the second synchro 23 are stopped in the former. Since the latter is rotating, the synchronous control shown in FIG. 4 is executed. In this case, since the starter driven gear 21B and the output shaft 16 that are connected to each other by the first sync 23 are stopped, the first sync 23 can be switched without particularly performing synchronization control. it can.

  FIG. 4 is a flowchart for explaining an example of the synchronous control when a shift instruction from the neutral state to the start state (start standby state) is performed. The routine shown in this flowchart is performed every predetermined short time. Repeatedly executed. First, it is determined whether or not a command to switch from the neutral position or neutral range (N) to the drive position or drive range (D) is output (step S1). If the command to switch from the neutral range (N) to the drive range (D) has not yet been output, and if a negative determination is made in this step S1, the subsequent control is not performed and this routine is temporarily terminated. .

  On the other hand, if the command to switch from the neutral range (N) to the drive range (D) is output, and if a positive determination is made in step S1, the process proceeds to step S2, and the first lock valve 43 is turned on. Controlled to ON state. That is, the pilot pressure Psol1 is applied to the first lock valve 43. Further, the extrusion volume q1 of the first pump motor 12 is controlled from zero to the maximum (Max) (step S3).

  Subsequently, the first switching valve 39 and the third switching valve 46 are controlled to be in the ON state (steps S4 and S5). That is, the pilot pressure Psol3 is applied to the first switching valve 39, and the pilot pressure Psol6 is applied to the third switching valve 46, respectively. Then, the extrusion volume q2 of the second pump motor 13 is gradually increased (step S6). That is, volume control (capacity control) of the second pump motor 13 is executed.

  The state of control at this point is shown in FIG. 5 together with other control states. In FIG. 5, symbol q1 denotes the extrusion volume of the first pump motor 12, q2 denotes the extrusion volume of the second pump motor 13, and Sol1 to Sol6 denote solenoid valves for outputting the pilot pressures Psol1 to Psol6, respectively. For the solenoid valves Sol1 to Sol6, “x” marks indicate an OFF state, and “◯” marks indicate an ON state. The control example shown in the flowchart of FIG. 4 corresponds to a state where “N → Start” is described in the “Activation” column in the chart of FIG.

  FIG. 6 shows a state in which the control in steps S1 to S6 is executed. In this state, the pressure oil accumulated in the accumulator 45 is discharged to the oil passage 15 of the closed circuit CC via the discharge oil passage 47. The oil passage 14 is communicated with a check valve 40 capable of maintaining a predetermined pressure, the first pump motor 12 is shut off from the closed circuit CC by the first lock valve 43, and the second pump motor Since the extrusion volume q2 of 13 is gradually increased, the pressure oil discharged from the accumulator 45 is supplied to the second pump motor 13 from the discharge port 13D side.

  Therefore, the second pump motor 13 is driven as a motor while the discharge pressure on the suction port 13S side is maintained at a predetermined pressure by the check valve 40. In this case, if the hydraulic pressure acting on the second pump motor 13 is P and the flow rate of the pressure oil is Q, the torque T is “T = P · Q / 2π”. That is, the torque T is gradually increased by gradually increasing the extrusion volume q2, and the rotation speed of the output shaft of the second pump motor 13, that is, the motor shaft 11, is increased. In addition, if the pilot pressure Psol6 with respect to the 3rd switching valve 46 is controlled, the torque T can be changed in magnitude.

  The situation is shown in an alignment chart in FIG. Since pressure oil is supplied from the discharge port 13D side to the stopped second pump motor 13, when the extrusion volume q2 is increased, the second pump motor 13 gradually starts to reversely rotate. Therefore, since the sun gear 4S of the second planetary gear mechanism 4 connected to the second pump motor 13 rotates in the reverse direction, the rotation speed of the carrier 4C gradually decreases and finally stops. As described above, since the first speed drive gear 20A to be connected by the second sync 23 is stopped at that time, the rotation speed of the carrier 4C becomes zero, so that the second intermediate shaft 10, that is, the second sync 23 The sleeve also stops, so that the two members to be connected by the second sync 23 are in rotation synchronization.

  As described above, when the rotation speed of the first speed drive gear 20A and the rotation speed of the second intermediate shaft 10 are synchronized when the second synchro 23 is switched to the engaged state, the switching valves 39, 46 as described above. The first lock valve 43 is controlled, and the pressure oil accumulated in the accumulator 45 is supplied to the second pump motor 13 to drive the second pump motor 13 as a motor, whereby the carrier 4C, that is, the second intermediate shaft 10 is driven. The number of rotations can be quickly reduced. As a result, rotation synchronization between the first speed drive gear 20A and the second intermediate shaft 10 can be promoted, and the time required for switching the second synchro 23 can be shortened.

  In the control example shown in FIG. 4, the determination of the rotation synchronization in the above-described synchronization control is based on the respective rotation speeds detected by the respective rotation speed sensors 29, 30, 31, 32, that is, the rotation speed Nin of the input member 2, the axle 28. The rotation speed Nout of the first pump motor 12, the rotation speed NPM1 of the first pump motor 12, and the rotation speed NPM2 of the second pump motor 13 can be performed. Specifically, the respective rotational speeds are detected (step S7), and the rotational speed of the carrier 4C or the differential rotational speed between the carrier 4C and the first speed drive gear 20A is calculated from the detected values (step S7). S8). Then, the rotation synchronization is determined based on whether or not the difference rotational speed has become zero or whether or not it has become equal to or less than a predetermined determination reference value (step S9).

  Therefore, if the second sync 23 has not yet been synchronized in rotation, and if a negative determination is made in step S9, the process returns to step S6 and the previous control is repeated. That is, the control in steps S6 to S8 is repeatedly executed until the rotation is synchronized.

  On the other hand, if the second sync 23 is synchronized with the rotation, and if the determination in step S9 is affirmative, the process proceeds to step S10, and the third switching valve 46 is controlled to be in the OFF state. That is, the pilot pressure Psol6 applied to the third switching valve 46 is released, and as a result, the discharge oil passage 47 is shut off and the supply of pressure oil from the accumulator 45 to the second pump motor 13 is stopped.

  Subsequently, the sleeve of the first sync 22 is moved from the neutral position “N” to the position “S” on the start gear pair 21 side, the start driven gear 21B and the output shaft 16 are connected, and the second sync. The sleeve 23 is moved from the neutral position “N” to the position “1st” on the first speed gear pair 20 side to connect the first speed drive gear 20A and the second intermediate shaft 10 (step S11). That is, torque transmission by the starting gear pair 21 is possible between the first intermediate shaft 8 and the output shaft 16. In addition, torque transmission by the first speed gear pair 20 is possible between the second intermediate shaft 10 and the output shaft 16. In other words, the first speed fixed shift stage can be set.

  As described above, when the synchros 22 and 23 are switched, the sync speeds 22 and 23 are in a synchronized state, and the rotation speeds of the two members to be connected are the same or substantially the same. Does not change abruptly or drive torque changes with it, and there is almost no slippage or wear due to it. Accordingly, since no synchronization function is particularly required for each of the synchros 20 and 21, a simple synchronization coupling mechanism can be used, or a switching mechanism (clutch mechanism) having no synchronization function such as a dog clutch mechanism can be used. Become.

  When the second synchro 23 is switched to the engaged state as described above and the second intermediate shaft 10, that is, the carrier 4C is connected to the output shaft 16 via the first speed gear pair 20, the carrier 4C Torque is applied from the output shaft 16 so as to stop the torque, and accordingly, the torque appears on the motor shaft 11 on the second pump motor 13 side. Therefore, in order to maintain the carrier 4C, that is, the second intermediate shaft 10 in a stopped state, the extrusion volume q2 of the second pump motor 13 is controlled to zero (step S12). Therefore, the second pump motor 13 and the motor shaft 11 are idled so that a so-called torque is released, torque is not transmitted to the second intermediate shaft 10 and the output shaft 16, and the stopped state is maintained.

  Moreover, the 1st switching valve 39 currently controlled by the ON state is controlled by the OFF state (step S13). Therefore, the oil passage 14 communicated with the oil pan 34 is blocked with respect to the oil pan 34, and the pump motors 12 and 13 are communicated with each other in a closed circuit. In this case, since the check valve 36 is closed, no pressure oil flows from the oil passage 14 toward the charge pump 33. And the 1st lock valve 43 is controlled to an OFF state (Step S14). That is, the first pump motor 12 is brought into communication with the closed circuit CC. Thereafter, this routine is once terminated.

  The time chart of FIG. 8 shows changes in the hydraulic pressure of each part of the hydraulic circuit, the hydraulic pressure of the accumulator 45, and the discharge pressure of the charge pump 33 when the synchronous control shown in FIG. 4 is executed. As shown in FIG. 8, the discharge pressure PChp of the charge pump 33 driven by the power of the engine 1 is always constant. Further, since the pressure oil does not flow in the pressure accumulation oil passage 48, the oil pressure Pd of the pressure accumulation oil passage 48 is also constant at a predetermined pressure. When the first switching valve 39 is controlled to be in the ON state in step S4 in the flowchart of FIG. 4, the oil passage 14 is communicated with the oil pan 34 via the check valve 40, and the second pump motor in the oil passage 14 is connected. The oil pressure Pa between the 13 inlets 13 </ b> S and the branch point B decreases to a predetermined oil pressure determined by the check valve 40.

  Next, when the third switching valve 46 is controlled to be in the ON state in step S5, the pressure oil accumulated in the accumulator 45 is discharged, and the hydraulic pressure PAcc of the accumulator 45 gradually decreases by the amount of the discharge, and the accumulator 45 The oil pressure Pb of the discharge oil passage 47 and the oil passage 15 to which the pressure oil discharged from the oil is supplied increases to the discharge pressure of the accumulator 45.

  The hydraulic pressure Pb of the discharge oil passage 47 and the oil passage 15 is such that the third switching valve 46 is controlled to be OFF in step S10, the discharge oil passage 47 is shut off, and the supply of pressure oil from the accumulator 45 is stopped. As a result, the normal hydraulic pressure determined by the discharge pressure of the charge pump 33 is reduced. When the first switching valve 39 is controlled to be in the OFF state in step S13, the hydraulic pressure Pa between the suction port 13S of the second pump motor 13 in the oil passage 14 and the branch point B is the check valve 36, that is, the charge pump. 33 and the oil passage 14 are communicated to return to a normal hydraulic pressure determined by the discharge pressure of the charge pump 33.

  Next, when starting from the start state (start standby state) and the first speed fixed shift stage is set, and the first sync 23 is switched to the third speed gear pair 19 side while transmitting torque in this state, That is, an operation when setting a so-called upshift standby state to the second speed or when upshifting from the start state to the second speed fixed shift stage across the first speed fixed shift stage will be described.

  First, in the start state, the second pump motor 13 is idling in the reverse rotation direction, and no torque is applied to the first pump motor 12. Therefore, when the volume control for gradually increasing the extrusion volume q2 of the second pump motor 13 is performed, the reaction force accompanying the generation of the hydraulic pressure appears on the output shaft, that is, the motor shaft 11. That is, if the extrusion volume q2 of the second pump motor 13 is gradually increased, the rotational speed of the second pump motor 13 is gradually decreased. Further, the pressure oil discharged from the second pump motor 13 is supplied to the suction port 12S of the first pump motor 12, and the first pump motor 12 starts to rotate forward. Therefore, power is transmitted from the second pump motor 13 to the first pump motor 12 via the fluid.

  When the second pump motor 13 has an extrusion volume q2, a reaction force is generated due to pressurizing and discharging the oil, so that the rotational speed gradually decreases and the extrusion volume q2 is maximized. 2 The pump motor 13 stops. The reaction force acts to rotate the carrier 4C of the second planetary gear mechanism 4 in the forward direction, the torque is transmitted to the output shaft 16 via the first speed gear pair 20, and from the output shaft 16 to the axle 28. Since it is transmitted, the vehicle starts.

  At the same time, the first pump motor 12 receives pressure oil from the second pump motor 13 and rotates forward to output torque, so that the motor shaft 9 and the starting drive gear 21A connected thereto rotate forward. . That is, the torque output from the first pump motor 12 is transmitted to the output shaft 16 via the starting gear pair 21 and the first sync 22. In other words, power is transmitted to the output shaft 16 through the first speed gear pair 20 and power is transmitted through the pump motors 12 and 13 and the starting gear pair 21.

  Then, the state where the extrusion volume q2 of the second pump motor 13 is maximized and the rotation is stopped is the first speed which is the fixed gear stage. The gear ratio is a value mainly corresponding to the gear ratio of the first-speed gear pair 20, and the gear ratio up to that time changes continuously, resulting in a so-called continuously variable transmission state. Therefore, a gear ratio larger than the first speed is set at the time of start, and a large driving force can be obtained. Note that, in the state where the first speed fixed shift stage is set, the second pump motor 13 does not discharge the pressure oil, so the pushing volume q1 of the first pump motor 12 is set to zero. Further, since the first synchro 22 is engaged, the first pump motor 12 idles in the forward rotation direction together with the motor shaft 9.

  As described above, in the above transmission TM, when starting, the gear train is first connected to the start state by the switching mechanism (clutch mechanism), and in this state, the hydraulic pressure and the extrusion volume q1 of the pump motors 12 and 13 are connected. , Q2 are controlled to transmit power to the output shaft 16. Such control is performed in the same manner when shifting between the first speed and the second speed, which are fixed gears. Then, when switching the engagement state of the switching mechanism (clutch mechanism) for that purpose, the same control as the so-called synchronous control described above is executed. In order to shift this from the first speed to the second speed, the first sync 22 and the third sync 24 are switched from the start state to the second speed fixed gear state, that is, upshift to the second speed. The case where the standby state is set will be described as follows.

  FIG. 9 is a flowchart for explaining an example of the control, and this corresponds to a state where “start → 2nd” is described in the “operation” column in the chart of FIG. Further, the flowchart of FIG. 9 showing an example of control in this case is a partial modification of the flowchart of FIG. 4 described above. Therefore, the control steps similar to the control contents in the flowchart of FIG. The same step numbers as those in the flowchart of FIG. 4 are given, and detailed description of the control contents is omitted.

  First, it is determined whether or not a shift command from the start state to the second speed fixed shift stage state is output (step S21). If the command has not been output yet and the determination is negative in this step S21, the routine is temporarily terminated without performing the subsequent control.

  On the other hand, if an affirmative determination is made in step S21 by outputting a command for switching from the start state to the second speed fixed shift stage state, the process proceeds to step S22, and the second lock valve 44 is turned on. Controlled by the state. That is, the pilot pressure Psol2 is applied to the second lock valve 44. Further, the sleeve of the first sync 22 is moved from the position “S” on the start gear pair 21 side to the neutral position “N”, and the power transmission state between the start driven gear 21B and the output shaft 16 is cut off. (Step S23).

  Subsequently, the first switching valve 39 and the third switching valve 46 are controlled to be in the ON state (steps S4 and S5), and the extrusion volume q1 of the first pump motor 12 is gradually increased (step S24). That is, the volume control of the first pump motor 12 is executed.

  Further, FIG. 10 shows a state in which the control in steps S21 to S24 is executed. In this state, the pressure oil accumulated in the accumulator 45 is discharged to the oil passage 15 of the closed circuit CC via the discharge oil passage 47. The oil passage 14 is communicated with a check valve 40 capable of maintaining a predetermined pressure, and the second pump motor 13 is blocked from the closed circuit CC by the second lock valve 44, and the first pump motor Since the extrusion volume q1 of 12 is gradually increased, the pressure oil discharged from the accumulator 45 is supplied to the first pump motor 12 from the discharge port 12D side.

  Therefore, the first pump motor 12 is driven as a motor while the discharge pressure on the suction port 12S side is maintained at a predetermined pressure by the check valve 40. Then, the rotational speed of the output shaft of the first pump motor 12, that is, the motor shaft 9 is increased by gradually increasing the extrusion volume q1.

  This state is shown in a collinear diagram in FIG. In this state, although the torque in the reverse rotation direction transmitted from the engine 1 acts on the second pump motor 13, the second pump motor 13 is shut off from the closed circuit CC by the second lock valve 44 and pressurized oil Therefore, the output shaft does not rotate, and a reaction force acts on the motor shaft 11 and the sun gear 4S connected thereto. Accordingly, the carrier 4C, which is the output element of the second planetary gear mechanism 4, is decelerated with respect to the ring gear 4R and rotates forward, and the torque is output to the output shaft 16 via the second intermediate shaft 10 and the first speed gear pair 20. To the first gear ratio.

  On the other hand, the first pump motor 12 is supplied with pressure oil from the accumulator 45 to the discharge port 12D, and the suction port 12S is communicated with the oil pan 34 via the check valve 40. Torque is output according to the hydraulic pressure and extrusion volume q1. The pressure oil supply direction is a direction from the discharge port 12D to the suction port 12S, and is a direction in which the first pump motor 12 is rotated in the reverse direction. At the first speed, the first pump motor 12 is idling in the forward rotation direction. Therefore, by gradually increasing the extrusion volume q1 of the first pump motor 12, the rotation speed gradually decreases. In the above step S24, the volume control is executed in this way, and as a result, the rotational speed of the motor shaft 9 on the first pump motor 12 side and the sun gear 3S of the first planetary gear mechanism 3 connected to the motor shaft 9 gradually decreases. .

  And if the pressure oil which the accumulator 45 discharges is further supplied to the discharge port 12D of the 1st pump motor 12, the 1st pump motor 12 will reversely rotate with the torque according to the hydraulic pressure and extrusion volume q1. Then, when the first pump motor 12 and the sun gear 3S connected thereto via the motor shaft 9 are reversely rotated, the rotational speed of the carrier 3C of the first planetary gear mechanism 3 is further reduced, and finally the carrier 3C The rotation speed of the connected first intermediate shaft 8 substantially matches the rotation speed of the second speed drive gear 18A. That is, the two members to be connected by the third sync 24 are in a state of being rotationally synchronized.

  As described above, when the rotation speed of the second speed drive gear 18A and the rotation speed of the first intermediate shaft 8 are synchronized when the third sync 24 is switched to the engaged state, the switching valves 39, 46 are used as described above. The second lock valve 44 is controlled and the pressure oil accumulated in the accumulator 45 is supplied to the first pump motor 12 to drive the first pump motor 12 as a motor, whereby the carrier 3C, that is, the first intermediate shaft 8 The number of rotations can be quickly reduced. As a result, rotation synchronization between the second speed drive gear 18A and the first intermediate shaft 8 can be promoted, and the time required for switching the third synchro 24 can be shortened.

  As described above, the synchronization control in switching the third sync 24 is executed, and when the third sync 24 is in the rotation synchronization state, the third switching valve 46 is controlled to be in the OFF state (step S10), and then the third sync. The sleeve of the synchro 24 is moved from the neutral position “N” to the position “2nd” on the second speed gear pair 18 side to connect the second speed drive gear 18A and the first intermediate shaft 8 (step S25). That is, torque transmission by the second speed gear pair 18 is possible between the first intermediate shaft 8 and the output shaft 16. In other words, the second speed fixed shift stage can be set. In that case, since the rotational speeds of the second speed drive gear 18A and the first intermediate shaft 8 are substantially the same as described above, a change in the rotational speed caused by the third sync 24 being engaged or a sudden change. There is no torque change. In addition, the third sync 24 does not slip in the rotational direction.

  When the sleeve of the third synchro 24 is switched from the neutral position “N” to the position “2nd” on the second speed gear pair 18 side and the second speed drive gear 18A and the first intermediate shaft 8 are connected, The extrusion volume q1 of the one pump motor 12 is controlled to zero (step S26), and the first pump motor 12 and the motor shaft 9 are idled. Further, the first switching valve 39 is controlled to be in an OFF state (step S13), and therefore the oil passage 14 is blocked with respect to the oil pan 34 that is a drain location. Further, the second lock valve 44 is controlled to be in the OFF state (step S27), and therefore the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other.

  Thus, when setting the upshift standby state to the second speed, the pump motors 12 and 13 are disconnected from each other, and the first pump motor 12 is controlled by the hydraulic pressure discharged from the accumulator 45. By controlling the extrusion volume q1, the rotation speed control (synchronous control) is executed so that the third synchro 24 is in a synchronized state. Therefore, there is no change in rotational speed or torque caused by operating the third synchro 24 in the engaged state, so that the third synchro 24 can be quickly operated in the engaged state and control with good responsiveness is possible. become. Further, since the third synchronizer 24 does not slip in the rotational direction, its durability can be improved, or a dog clutch mechanism having no synchronization function can be used in place of the synchronous coupling mechanism.

  Next, when traveling at the gear ratio from the first speed to the second speed, when upshifting to the third speed fixed speed stage across the second speed fixed speed stage, that is, waiting for an upshift to the so-called third speed The operation when the state is set will be described. Even in the case of an upshift across the second speed fixed speed, that is, a speed change between the first speed and the third speed, which is the fixed speed, the switching state of the switching mechanism (clutch mechanism) is switched. At this time, the same control as the so-called synchronous control described above is executed.

  FIG. 12 is a flowchart for explaining an example of the control, and this corresponds to a state where “1st → 3rd” is described in the “actuation” column in the chart of FIG. Further, the flowchart of FIG. 12 showing a control example in this case is a partial modification of the flowchart of FIG. 4 described above, and therefore the control steps similar to the control contents in the flowchart of FIG. 4 are shown in the flowchart of FIG. The same step numbers as those in the flowchart of FIG. 4 are given, and detailed description of the control contents is omitted.

  First, it is determined whether or not a shift command from the first speed to the third speed is output (step S31). If the command has not been output yet and the determination is negative in this step S31, the routine is temporarily terminated without performing the subsequent control.

  When a command to switch from the first speed to the third speed is output, the first lock valve 43 is controlled to be in the ON state (step S2), and the sleeve of the second synchro 23 is on the first speed gear pair 20 side. The position is moved from the position “1st” to the neutral position “N”, and the power transmission state between the first speed drive gear 20A and the output shaft 16 is interrupted (step S32).

  Subsequently, the first switching valve 39 and the third switching valve 46 are controlled to be in the ON state (steps S4 and S5), and the extrusion volume q2 of the second pump motor 13 is gradually increased (step S6). That is, the volume control of the second pump motor 13 is executed.

  FIG. 13 shows a state in which the control in steps S31 to S6 is executed. In this state, the pressure oil accumulated in the accumulator 45 is discharged to the oil passage 15 of the closed circuit CC via the discharge oil passage 47. The oil passage 14 is communicated with a check valve 40 capable of maintaining a predetermined pressure, the first pump motor 12 is shut off from the closed circuit CC by the first lock valve 43, and the second pump motor Since the extrusion volume q2 of 13 is gradually increased, the pressure oil discharged from the accumulator 45 is supplied to the second pump motor 13 from the discharge port 13D side.

  Therefore, the second pump motor 13 is driven as a motor while the discharge pressure on the suction port 13S side is maintained at a predetermined pressure by the check valve 40. Then, the rotational speed of the output shaft of the second pump motor 13, that is, the motor shaft 11 is increased by gradually increasing the extrusion volume q2.

  This state is shown in a collinear diagram in FIG. In this state, although the torque in the reverse rotation direction transmitted from the engine 1 acts on the first pump motor 12, the first pump motor 12 is shut off from the closed circuit CC by the first lock valve 43 and pressurized oil Therefore, the output shaft does not rotate, and a reaction force acts on the motor shaft 9 and the sun gear 3S connected thereto. Therefore, the carrier 3C, which is the output element of the first planetary gear mechanism 3, is decelerated with respect to the ring gear 3R and rotates forward, and the torque is output to the output shaft 16 via the first intermediate shaft 8 and the second speed gear pair 18. To the gear ratio of the second speed.

  On the other hand, the second pump motor 13 is supplied with pressure oil from the accumulator 45 to the discharge port 13D, and the suction port 13S is communicated with the oil pan 34 via the check valve 40. Torque is output according to the hydraulic pressure and extrusion volume q2. The pressure oil supply direction is a direction from the discharge port 13D toward the suction port 13S, and is a direction in which the second pump motor 13 is rotated in the reverse direction. At the second speed, the second pump motor 13 is idling in the forward rotation direction. Therefore, by gradually increasing the extrusion volume q2 of the second pump motor 13, the rotational speed gradually decreases. In the above step S6, the volume control is executed in this way, and as a result, the rotational speed of the motor shaft 11 on the second pump motor 13 side and the sun gear 4S of the second planetary gear mechanism 4 connected thereto is gradually reduced. .

  And if the pressure oil which the accumulator 45 discharges is further supplied to the discharge port 13D of the 2nd pump motor 13, the 2nd pump motor 13 will reversely rotate with the torque according to the hydraulic pressure and extrusion volume q2. Then, when the second pump motor 13 and the sun gear 4S connected thereto via the motor shaft 11 are rotated in the reverse direction, the rotational speed of the carrier 4C of the second planetary gear mechanism 4 further decreases, and finally the carrier 4C The rotation speed of the connected second intermediate shaft 10 substantially matches the rotation speed of the third speed drive gear 19A. That is, the two members to be connected by the second sync 23 are in a state of being synchronized in rotation.

  Thus, when synchronizing the rotation speed of the 3rd speed drive gear 19A and the rotation speed of the 2nd intermediate shaft 10 when switching the 2nd synchro 23 to an engagement state, as above-mentioned, each switching valve 39,46. The first lock valve 43 is controlled, and the pressure oil accumulated in the accumulator 45 is supplied to the second pump motor 13 to drive the second pump motor 13 as a motor, whereby the carrier 4C, that is, the second intermediate shaft 10 is driven. The number of rotations can be quickly reduced. As a result, rotation synchronization between the third speed drive gear 19A and the second intermediate shaft 10 can be promoted, and the time required for switching the second synchro 23 can be shortened.

  As described above, the synchronization control in the switching of the second synchro 23 is executed, and when the second synchro 23 is in the rotation synchronization state, the third switching valve 46 is controlled to the OFF state (step S10), and then the second The sleeve of the synchro 23 is moved from the neutral position “N” to the position “3rd” on the third speed gear pair 19 side to connect the third speed drive gear 19A and the second intermediate shaft 10 (step S33). That is, torque transmission by the third speed gear pair 19 is possible between the second intermediate shaft 10 and the output shaft 16. In other words, the third speed fixed shift stage can be set. In this case, since the rotation speeds of the third speed drive gear 19A and the second intermediate shaft 10 are substantially the same as described above, a change in the rotation speed caused by the second synchro 23 being engaged or a sudden change. There is no torque change. Further, the second sync 23 does not slip in the rotational direction.

  When the sleeve of the second synchro 23 is switched from the neutral position “N” to the position “3rd” on the third speed gear pair 19 side, the third speed drive gear 19A and the second intermediate shaft 10 are connected. The extrusion volume q2 of the two-pump motor 13 is controlled to zero (step S12), and the second pump motor 13 and the motor shaft 11 are idled. Further, the first switching valve 39 is controlled to be in an OFF state (step S13), and therefore the oil passage 14 is blocked with respect to the oil pan 34 that is a drain location. Further, the first lock valve 43 is controlled to be in an OFF state (step S14), and therefore the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other.

  As described above, when setting the upshift standby state to the third speed, the pump motors 12 and 13 are separated from each other, as in the case of setting the upshift standby state to the second speed described above. By making the second pump motor 13 controllable by the hydraulic pressure discharged from the accumulator 45 and controlling the extrusion volume q2, the rotation speed control (synchronous control) is executed so that the second synchro 23 is in a synchronized state. The For this reason, there is no change in the rotational speed or torque caused by operating the second synchro 23 in the engaged state, so that the second synchro 23 can be quickly moved into the engaged state and control with good responsiveness is possible. become. Further, since the second synchro 23 does not slip in the rotational direction, its durability can be improved, or a dog clutch mechanism or the like having no synchronization function can be used instead of the synchronization coupling mechanism.

  FIG. 15 is a time chart showing changes in the hydraulic pressure of each part of the hydraulic circuit, the hydraulic pressure of the accumulator 45, and the discharge pressure of the charge pump 33 when the synchronous control shown in FIG. 12 is executed. As shown in FIG. 15, the discharge pressure PChp of the charge pump 33 driven by the power of the engine 1 is always constant. Also in this case, since the pressure oil does not flow in the pressure accumulation oil passage 48, the oil pressure Pd of the pressure accumulation oil passage 48 is also constant at a predetermined pressure. Then, when the first lock valve 43 is controlled to be in the ON state in step S2 in the flowchart of FIG. 12, the branch point B of the oil passage 14 and the suction port 12S of the first pump motor 12 are shut off, and the oil The oil pressure Pa between the suction port 13 </ b> S of the second pump motor 13 in the path 14 and the branch point B is reduced to the discharge pressure PChp of the charge pump 33. The hydraulic pressure Pa is a predetermined hydraulic pressure determined by the check valve 40 when the first switching valve 39 is controlled to be in the ON state in step S4 and the oil passage 14 is communicated with the oil pan 34 via the check valve 40. To drop.

  Next, when the third switching valve 46 is controlled to be in the ON state in step S5, the pressure oil accumulated in the accumulator 45 is discharged, and the hydraulic pressure PAcc of the accumulator 45 gradually decreases by the amount of the discharge, and the accumulator 45 The oil pressure Pb of the discharge oil passage 47 and the oil passage 15 to which the pressure oil discharged from the oil is supplied increases to the discharge pressure of the accumulator 45. In addition, the first lock valve 43 is controlled to be in the ON state and shut off from the closed circuit CC, so that the suction port 12S and the branch point B of the first pump motor 12 of the oil passage 14 on the high pressure side are provided. The hydraulic pressure Pc is further increased when the third switching valve 46 is controlled to be in the ON state and pressure oil is supplied from the accumulator 45.

  The hydraulic pressure Pb of the discharge oil passage 47 and the oil passage 15 is controlled so that the third switching valve 46 is turned off in step S10, the discharge oil passage 47 is shut off, and the supply of pressure oil from the accumulator 45 is stopped. As a result, the normal hydraulic pressure determined by the discharge pressure of the charge pump 33 is reduced. Further, the hydraulic pressure Pc between the suction port 12S of the first pump motor 12 and the branch point B in the oil passage 14 is also controlled so that the third switching valve 46 is in the OFF state, and the supply of pressure oil from the accumulator 45 is stopped. As a result, the hydraulic pressure level at the beginning of the control is restored.

  Subsequently, when the first switching valve 39 is controlled to be in the OFF state in step S13, the hydraulic pressure Pa between the suction port 13S of the second pump motor 13 in the oil passage 14 and the branch point B is set to the check valve 36, that is, the charge. The pump 33 and the oil passage 14 are communicated, and the normal hydraulic pressure determined by the discharge pressure of the charge pump 33 is restored.

  When the first lock valve 43 is OFF-controlled in step S14, the shutoff state of the oil passage 14 is canceled, that is, the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other, and the oil passage 14 The hydraulic pressure Pa between the suction port 13S of the second pump motor 13 and the branch point B returns to the initial hydraulic pressure level at the start of control.

  Next, when traveling at the gear ratio from the second speed to the third speed, when upshifting to the fourth speed fixed speed stage across the third speed fixed speed stage, that is, waiting for upshift to the so-called fourth speed The operation when setting the state will be described. Even in the case of upshifting across the third speed fixed speed stage, that is, the speed change between the second speed and the fourth speed, which are the fixed speed stages, switching of the engagement state of the switching mechanism (clutch mechanism) for that purpose At this time, the same control as the so-called synchronous control described above is executed.

  FIG. 16 is a flowchart for explaining an example of the control, and this corresponds to a state in which “2nd → 4th” is described in the “actuation” column in the chart of FIG. In addition, the flowchart of FIG. 16 showing an example of control in this case is a partial modification of the flowchart of FIG. 4 described above. Therefore, the control steps similar to the control contents in the flowchart of FIG. The same step numbers as those in the flowchart of FIG.

  First, it is determined whether or not a shift command from the second speed to the fourth speed has been output (step S41). If the instruction has not been output yet and the determination is negative in step S41, the control is not performed and this routine is temporarily terminated.

  When a command to switch from the second speed to the fourth speed is output, the second lock valve 44 is controlled to be in the ON state (step S42), and the sleeve of the third sync 24 is on the second speed gear pair 18 side. The position is moved from the position “2nd” to the neutral position “N”, and the power transmission state between the second speed drive gear 18A and the output shaft 16 is interrupted (step S43).

  Subsequently, the first switching valve 39 and the third switching valve 46 are controlled to be in the ON state (steps S4 and S5), and the extrusion volume q1 of the first pump motor 12 is gradually increased (step S44). That is, the volume control of the first pump motor 12 is executed.

  FIG. 17 shows a state in which the control in steps S41 to S44 is executed. This state is shown in FIG. 10 when the above-described upshift standby state to the second speed is set except that the engagement position of the second synchro 23 and the moving direction of the sleeve of the third synchro 24 are different. It is the same as the state. Further, the alignment chart in this state is the same as the alignment chart shown in FIG. 11 when the above-described upshift standby state to the second speed is set.

  That is, in this state, although the torque in the reverse rotation direction transmitted from the engine 1 acts on the first pump motor 12, the second pump motor 13 is blocked from the closed circuit CC by the second lock valve 44. Since the pressure oil cannot be discharged, the output shaft does not rotate, and a reaction force acts on the motor shaft 11 and the sun gear 4S connected thereto. Accordingly, the carrier 4C that is the output element of the second planetary gear mechanism 4 is decelerated and rotated forward with respect to the ring gear 4R, and the torque thereof is output via the second intermediate shaft 10 and the third speed gear pair 19 to the output shaft 16. To the third speed gear ratio.

  On the other hand, the first pump motor 12 is supplied with pressure oil from the accumulator 45 to the discharge port 12D, and the suction port 12S is communicated with the oil pan 34 via the check valve 40. Torque is output according to the hydraulic pressure and extrusion volume q1. The pressure oil supply direction is a direction from the discharge port 12D to the suction port 12S, and is a direction in which the first pump motor 12 is rotated in the reverse direction. At the third speed, the first pump motor 12 is idling in the reverse rotation direction. Therefore, by gradually increasing the extrusion volume q1 of the first pump motor 12, the rotation speed gradually decreases. In the above-described step S44, the volume control is executed in this way, and as a result, the rotational speed of the motor shaft 9 on the first pump motor 12 side and the sun gear 3S of the first planetary gear mechanism 3 connected thereto is gradually reduced. .

  And if the pressure oil which the accumulator 45 discharges is further supplied to the discharge port 12D of the 1st pump motor 12, the 1st pump motor 12 will reversely rotate with the torque according to the hydraulic pressure and extrusion volume q1. Then, when the first pump motor 12 and the sun gear 3S connected thereto via the motor shaft 9 are reversely rotated, the rotational speed of the carrier 3C of the first planetary gear mechanism 3 is further reduced, and finally the carrier 3C The rotation speed of the connected first intermediate shaft 8 substantially matches the rotation speed of the fourth speed drive gear 17A. That is, the two members to be connected by the third sync 24 are in a state of being rotationally synchronized.

  Thus, when synchronizing the rotation speed of the 4th speed drive gear 17A and the rotation speed of the 1st intermediate shaft 8 when switching the 3rd synchro 24 to an engagement state, as above-mentioned, each switching valve 39,46. The second lock valve 44 is controlled and the pressure oil accumulated in the accumulator 45 is supplied to the first pump motor 12 to drive the first pump motor 12 as a motor, whereby the carrier 3C, that is, the first intermediate shaft 8 The number of rotations can be quickly reduced. As a result, rotation synchronization between the fourth speed drive gear 17A and the first intermediate shaft 8 can be promoted, and the time required for switching the third synchro 24 can be shortened.

  As described above, the synchronization control in switching the third sync 24 is executed, and when the third sync 24 is in the rotation synchronization state, the third switching valve 46 is controlled to be in the OFF state (step S10), and then the third sync. The sleeve of the synchro 24 is moved from the neutral position “N” to the position “4th” on the fourth speed gear pair 17 side, and the fourth speed drive gear 17A and the first intermediate shaft 8 are connected (step S45). In other words, torque transmission by the fourth speed gear pair 17 is possible between the first intermediate shaft 8 and the output shaft 16. In other words, the fourth speed fixed shift stage can be set. In this case, since the rotational speeds of the fourth speed drive gear 17A and the first intermediate shaft 8 are substantially the same as described above, a change in the rotational speed caused by the third synchro 24 being engaged or a sudden change. There is no torque change. In addition, the third sync 24 does not slip in the rotational direction.

  When the sleeve of the third synchro 24 is switched from the neutral position “N” to the position “4th” on the fourth speed gear pair 17 side and the fourth speed drive gear 17A and the first intermediate shaft 8 are connected, The extrusion volume q1 of the one pump motor 12 is controlled to zero (step S46), and the first pump motor 12 and the motor shaft 9 are idled. Further, the first switching valve 39 is controlled to be in an OFF state (step S13), and therefore the oil passage 14 is blocked with respect to the oil pan 34 that is a drain location. Further, the second lock valve 44 is controlled to be in an OFF state (step S47), and therefore the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other.

  As described above, when setting the upshift standby state to the fourth speed, the pump motors 12 and 13 are connected to each other as in the case of setting the upshift standby state to the second speed or the third speed described above. The first pump motor 12 is controlled by the hydraulic pressure discharged from the accumulator 45, and the extrusion volume q1 is controlled to control the rotation speed so that the third sync 24 is in a synchronized state (synchronous control). ) Is executed. Therefore, there is no change in rotational speed or torque caused by operating the third synchro 24 in the engaged state, so that the third synchro 24 can be quickly operated in the engaged state and control with good responsiveness is possible. become. Further, since the third synchronizer 24 does not slip in the rotational direction, its durability can be improved, or a dog clutch mechanism having no synchronization function can be used in place of the synchronous coupling mechanism.

  Next, when traveling at the gear ratio from the fourth speed to the third speed, when downshifting to the second speed fixed speed stage across the third speed fixed speed stage, that is, so-called downshift waiting to the second speed The operation when the state is set will be described. Even in the case of a downshift across the third speed fixed speed, that is, a speed change between the fourth speed and the second speed, which is the fixed speed, the switching state of the switching mechanism (clutch mechanism) is switched. At this time, the same control as the so-called synchronous control described above is executed.

  FIG. 18 is a flowchart for explaining an example of the control, and this corresponds to a state where “4th → 2nd” is described in the “actuation” column in the chart of FIG. Further, the flowchart of FIG. 18 showing a control example in this case is a partial modification of the flowchart of FIG. 4 described above. Therefore, the control steps similar to the control contents in the flowchart of FIG. The same step numbers as those in the flowchart of FIG.

  First, it is determined whether or not a shift command from the fourth speed to the second speed has been output (step S51). If the instruction has not been output yet and the determination is negative in this step S51, the subsequent control is not performed and this routine is temporarily terminated.

  When a command to switch from the fourth speed to the second speed is output, the second lock valve 44 is controlled to be in the ON state (step S52), and the sleeve of the third sync 24 is on the fourth speed gear pair 17 side. The position is moved from the position “4th” to the neutral position “N”, and the power transmission state between the fourth speed drive gear 17A and the output shaft 16 is interrupted (step S53).

  Subsequently, the second switching valve 41 is controlled to be in an ON state (step S54). That is, the pilot pressure Psol4 is applied to the second switching valve 41. Further, the third switching valve 46 is controlled to be in the ON state (step S5), and the extrusion volume q1 of the first pump motor 12 is gradually increased (step S55). That is, the volume control of the first pump motor 12 is executed.

  FIG. 19 shows a state in which the control in steps S51 to S55 is executed. In this state, the pressure oil accumulated in the accumulator 45 is discharged to the oil passage 14 of the closed circuit CC via the discharge oil passage 47. The oil passage 15 is communicated with a check valve 42 that can maintain a predetermined pressure, and the second pump motor 13 is shut off from the closed circuit CC by the second lock valve 44, and the first pump motor Since the extrusion volume q1 of 12 is gradually increased, the pressure oil discharged from the accumulator 45 is supplied to the first pump motor 12 from the suction port 12S side.

  Therefore, the first pump motor 12 is driven as a motor while the discharge pressure on the discharge port 12D side is maintained at a predetermined pressure by the check valve 42. Then, the rotational speed of the output shaft of the first pump motor 12, that is, the motor shaft 9 is increased by gradually increasing the extrusion volume q1.

  This state is shown in the alignment chart in FIG. In this state, although the torque in the reverse rotation direction transmitted from the engine 1 acts on the second pump motor 13, the second pump motor 13 is shut off from the closed circuit CC by the second lock valve 44 and pressurized oil Therefore, the output shaft does not rotate, and a reaction force acts on the motor shaft 11 and the sun gear 4S connected thereto. Therefore, the carrier 4C, which is the output element of the second planetary gear mechanism 4, is decelerated with respect to the ring gear 4R and rotates in the forward direction, and the torque is output to the output shaft 16 via the second intermediate shaft 11 and the third speed gear pair 19. To the third speed gear ratio.

  On the other hand, the first pump motor 12 is supplied with pressure oil from the accumulator 45 to the suction port 12S, and the discharge port 12D communicates with the oil pan 34 via the check valve 42. Torque is output according to the hydraulic pressure and extrusion volume q1. The pressure oil supply direction is a direction from the suction port 12S toward the discharge port 12D, and is a direction in which the first pump motor 12 is normally rotated. At the third speed, the first pump motor 12 is idling in the reverse rotation direction. Therefore, by gradually increasing the extrusion volume q1 of the first pump motor 12, the rotation speed gradually decreases. In the above step S55, the volume control is executed in this way, and as a result, the rotational speed of the motor shaft 9 on the first pump motor 12 side and the sun gear 3S of the first planetary gear mechanism 3 connected thereto is gradually reduced. .

  Then, when the pressure oil discharged from the accumulator 45 is further supplied to the suction port 12S of the first pump motor 12, the rotation direction of the first pump motor 12 turns to normal rotation with a torque corresponding to the hydraulic pressure and the extrusion volume q1. , Its rotational speed increases. Then, when the first pump motor 12 and the sun gear 3S connected to the first pump motor 12 via the motor shaft 9 rotate in the forward direction, the rotation speed of the carrier 3C of the first planetary gear mechanism 3 increases, and finally the connection to the carrier 3C. The rotational speed of the first intermediate shaft 8 is substantially equal to the rotational speed of the second speed drive gear 18A. That is, the two members to be connected by the third sync 24 are in a state of being rotationally synchronized.

  As described above, when the rotation speed of the second speed drive gear 18A and the rotation speed of the first intermediate shaft 8 are synchronized when the third synchro 24 is switched to the engaged state, the switching valves 41 and 46 as described above. The second lock valve 44 is controlled and the pressure oil accumulated in the accumulator 45 is supplied to the first pump motor 12 to drive the first pump motor 12 as a motor, whereby the carrier 3C, that is, the first intermediate shaft 8 The number of rotations can be quickly increased. As a result, rotation synchronization between the second speed drive gear 18A and the first intermediate shaft 8 can be promoted, and the time required for switching the third synchro 24 can be shortened.

  As described above, the synchronization control in switching the third sync 24 is executed, and when the third sync 24 is in the rotation synchronization state, the third switching valve 46 is controlled to be in the OFF state (step S10), and then the third sync. The sleeve of the synchro 24 is moved from the neutral position “N” to the position “2nd” on the second speed gear pair 18 side, and the second speed drive gear 18A and the first intermediate shaft 8 are connected (step S56). That is, torque transmission by the second speed gear pair 18 is possible between the first intermediate shaft 8 and the output shaft 16. In other words, the second speed fixed shift stage can be set. In that case, since the rotational speeds of the second speed drive gear 18A and the first intermediate shaft 8 are substantially the same as described above, a change in the rotational speed caused by the third sync 24 being engaged or a sudden change. There is no torque change. In addition, the third sync 24 does not slip in the rotational direction.

  When the sleeve of the third synchro 24 is switched from the neutral position “N” to the position “2nd” on the second speed gear pair 18 side and the second speed drive gear 18A and the first intermediate shaft 8 are connected, The extrusion volume q1 of one pump motor 12 is controlled to zero (step S58), and the first pump motor 12 and the motor shaft 9 are idled. Further, the second switching valve 41 is controlled to be in an OFF state (step S58), and therefore the oil passage 15 is blocked with respect to the oil pan 34 that is a drain location. Further, the second lock valve 44 is controlled to be in the OFF state (step S59), and therefore the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other.

  As described above, when setting the downshift standby state to the second speed, the pump motors 12 and 13 are separated from each other in the same manner as in the case of setting the upshift standby state to each shift stage described above. By making the first pump motor 12 controllable by the hydraulic pressure discharged from the accumulator 45 and controlling the extrusion volume q1, the rotational speed control (synchronous control) is executed so that the third sync 24 is in a synchronized state. The Therefore, there is no change in rotational speed or torque caused by operating the third synchro 24 in the engaged state, so that the third synchro 24 can be quickly operated in the engaged state and control with good responsiveness is possible. become. Further, since the third synchronizer 24 does not slip in the rotational direction, its durability can be improved, or a dog clutch mechanism having no synchronization function can be used in place of the synchronous coupling mechanism.

  Next, when traveling down from the third speed to the second speed gear ratio and downshifting to the first speed fixed speed stage across the second speed fixed speed stage, that is, waiting for downshifting to the so-called first speed. The operation when the state is set will be described. Even in the case of downshifting across the second fixed speed, that is, shifting between the third speed and the first speed, which are fixed speeds, switching the engagement state of the switching mechanism (clutch mechanism) for that purpose At this time, the same control as the so-called synchronous control described above is executed.

  FIG. 21 is a flowchart for explaining an example of the control, and this corresponds to a state where “3rd → 1st” is described in the “actuation” column in the chart of FIG. Further, the flowchart of FIG. 21 showing a control example in this case is a partial modification of the flowchart of FIG. 4 described above, and therefore the control steps similar to the control contents in the flowchart of FIG. 4 are shown in the flowchart of FIG. The same step numbers as those in the flowchart of FIG.

  First, it is determined whether or not a shift command from the third speed to the first speed is output (step S61). If the instruction has not been output yet and the determination is negative in this step S51, the subsequent control is not performed and this routine is temporarily terminated.

  When a command to switch from the fourth speed to the second speed is output, the first lock valve 43 is controlled to be in an ON state (step S2), and the sleeve of the second synchro 23 is connected to the third speed gear pair 19 side. The position is moved from the position “3rd” to the neutral position “N”, and the power transmission state between the third speed drive gear 19A and the output shaft 16 is interrupted (step S62).

  Subsequently, the second switching valve 41 is controlled to be in an ON state (step S63), and the third switching valve 46 is controlled to be in an ON state (step S5). Then, the extrusion volume q2 of the second pump motor 13 is gradually increased (step S6). That is, the volume control of the second pump motor 12 is executed.

  FIG. 22 shows a state in which the control in steps S61 to S6 is executed. In this state, the pressure oil accumulated in the accumulator 45 is discharged to the oil passage 14 of the closed circuit CC via the discharge oil passage 47. The oil passage 15 is communicated with a check valve 42 that can maintain a predetermined pressure, and the first pump motor 12 is shut off from the closed circuit CC by the first lock valve 43, and the second pump motor Since the extrusion volume q2 of 13 is gradually increased, the pressure oil discharged from the accumulator 45 is supplied to the second pump motor 13 from the suction port 13S side.

  Therefore, the second pump motor 13 is driven as a motor while the discharge pressure on the discharge port 13D side is maintained at a predetermined pressure by the check valve 42. Then, the rotational speed of the output shaft of the second pump motor 13, that is, the motor shaft 11 is increased by gradually increasing the extrusion volume q2.

  This state is shown in a collinear diagram in FIG. In this state, although the torque in the reverse rotation direction transmitted from the engine 1 acts on the first pump motor 12, the first pump motor 12 is shut off from the closed circuit CC by the first lock valve 43 and pressurized oil Therefore, the output shaft does not rotate, and a reaction force acts on the motor shaft 9 and the sun gear 3S connected thereto. Therefore, the carrier 3C, which is the output element of the first planetary gear mechanism 3, is decelerated and rotated forward with respect to the ring gear 3R, and the torque is output to the output shaft 16 via the first intermediate shaft 9 and the second speed gear pair 18. To the gear ratio of the second speed.

  On the other hand, the second pump motor 13 is supplied with pressure oil from the accumulator 45 to the suction port 13S, and the discharge port 13D communicates with the oil pan 34 via the check valve 42. Torque is output according to the hydraulic pressure and extrusion volume q2. The pressure oil supply direction is a direction from the suction port 13S toward the discharge port 13D, and is a direction in which the second pump motor 13 is rotated forward. At the second speed, the second pump motor 13 is idling in the reverse rotation direction. Therefore, by gradually increasing the extrusion volume q2 of the second pump motor 13, the rotation speed gradually decreases. In the above step S6, the volume control is executed in this way, and as a result, the rotational speed of the motor shaft 11 on the second pump motor 13 side and the sun gear 4S of the second planetary gear mechanism 4 connected thereto is gradually reduced. .

  When the pressure oil discharged from the accumulator 45 is further supplied to the suction port 13S of the second pump motor 13, the rotation direction of the second pump motor 13 turns to normal rotation with a torque corresponding to the hydraulic pressure and the extrusion volume q2. , Its rotational speed increases. Then, when the second pump motor 13 and the sun gear 4S connected thereto via the motor shaft 11 are rotated forward, the rotation speed of the carrier 4C of the second planetary gear mechanism 4 is increased, and finally connected to the carrier 4C. The rotation speed of the second intermediate shaft 11 is substantially equal to the rotation speed of the first speed drive gear 20A. That is, the two members to be connected by the second sync 23 are in a state of being synchronized in rotation.

  As described above, when the rotation speed of the first speed drive gear 20A and the rotation speed of the second intermediate shaft 11 are synchronized when the second synchro 23 is switched to the engaged state, the switching valves 41 and 46 as described above. The first lock valve 43 is controlled, and the pressure oil accumulated in the accumulator 45 is supplied to the second pump motor 13 to drive the second pump motor 13 as a motor, whereby the carrier 4C, that is, the second intermediate shaft 11 is driven. The number of rotations can be quickly increased. As a result, rotation synchronization between the first speed drive gear 20A and the second intermediate shaft 11 can be promoted, and the time required for switching the second synchro 23 can be shortened.

  As described above, the synchronization control in the switching of the second synchro 23 is executed, and when the second synchro 23 is in the rotation synchronization state, the third switching valve 46 is controlled to the OFF state (step S10), and then the second The sleeve of the synchro 23 is moved from the neutral position “N” to the position “1st” on the first speed gear pair 20 side, and the first speed drive gear 20A and the second intermediate shaft 11 are connected (step S64). That is, torque transmission by the first speed gear pair 20 is possible between the second intermediate shaft 11 and the output shaft 16. In other words, the first speed fixed shift stage can be set. In that case, since the rotational speeds of the first speed driving gear 20A and the second intermediate shaft 11 are substantially the same as described above, the rotational speed changes or abruptly changes due to the second synchro 23 being engaged. There is no torque change. Further, the second sync 23 does not slip in the rotational direction.

  When the sleeve of the second synchro 23 is switched from the neutral position “N” to the position “1st” on the first speed gear pair 20 side and the first speed drive gear 20A and the second intermediate shaft 11 are connected, The extrusion volume q2 of the two-pump motor 13 is controlled to zero (step S12), and the second pump motor 13 and the motor shaft 11 are idled. Further, the second switching valve 41 is controlled to be in an OFF state (step S65), and therefore the oil passage 15 is blocked with respect to the oil pan 34 that is a drain location. Further, the first lock valve 43 is controlled to be in an OFF state (step S14), and therefore the suction ports 12S and 13S of the pump motors 12 and 13 are communicated with each other.

  As described above, when setting the downshift standby state to the first speed, each of the above-described upshift standby states to the respective gears and the downshift standby state to the second speed are set. The pump motors 12 and 13 are disconnected from each other, and the second pump motor 13 is controlled by the hydraulic pressure discharged from the accumulator 45. By controlling the extrusion volume q2, the second synchro 23 is brought into a synchronized state. Rotational speed control (synchronous control) is executed. For this reason, there is no change in the rotational speed or torque caused by operating the second synchro 23 in the engaged state, so that the second synchro 23 can be quickly moved into the engaged state and control with good responsiveness is possible. become. Further, since the second synchro 23 does not slip in the rotational direction, its durability can be improved, or a dog clutch mechanism or the like having no synchronization function can be used instead of the synchronization coupling mechanism.

  In the case of the shift corresponding to the state described as “2nd → start” and the shift corresponding to the state described as “N → Rev” in the “actuation” column in the chart of FIG. In this case, the rotational speed control (synchronous control) is executed in the same manner as in the case where the above-described upshift standby state for each gear stage and the downshift standby state for each gear stage are set. The explanation of the control contents in these cases and the action when those controls are executed can be understood by referring to the explanations of the flowcharts, state diagrams, collinear charts, etc. of each control described above. Is omitted.

  Next, the operation when pressure oil is accumulated in the accumulator 45 will be described. FIG. 24 is a flowchart for explaining the control when pressure oil is accumulated in the accumulator 45 during traveling at the gear ratio from the second speed to the third speed as an example of the control, and is shown in this flowchart. The routine is repeatedly executed every predetermined short time. First, it is determined whether or not a command for accumulating pressure oil is output to the accumulator 45 (step S71).

  The command for accumulating pressure oil in the accumulator 45 is a command that is output when the accumulated pressure of the accumulator 45 is less than a predetermined pressure α that is predetermined as a control threshold, and the accumulated pressure of the accumulator 45 is Is a command that is output in order to always maintain a desired pressure α or higher. Further, the pressure oil accumulated in the accumulator 45 is discharged to the closed circuit CC and supplied to one of the pump motors 12 (or 13) via the oil passage 14 or the oil passage 15, as will be described later. Used to drive the pump motor 12 (or 13). Therefore, the hydraulic pressure of the pressure oil accumulated in the accumulator 45, that is, the accumulated pressure of the accumulator 45 needs to be higher than the hydraulic pressure in the closed circuit CC. Therefore, the predetermined pressure α as the threshold value is equal to the closed circuit CC. Is set to a value higher than the oil pressure in the oil passage, specifically, the oil pressure in the oil passage that is relatively high in the closed circuit CC.

  Since the command for accumulating the pressure oil to the accumulator 45 has not been output yet, that is, the accumulator 45 has a pressure accumulation pressure equal to or higher than the predetermined pressure α, and it is not necessary to replenish the accumulator 45 with the pressure oil. If the determination is negative, the following control is not performed and this routine is temporarily terminated.

  On the other hand, when the command for accumulating the pressure oil is output to the accumulator 45, that is, the accumulated pressure of the accumulator 45 becomes less than the predetermined pressure α, and it is necessary to replenish the accumulator 45 with the pressure oil. If the determination in step S71 is affirmative, the process proceeds to step S72, and the third switching valve 46 is controlled to be in the OFF state. That is, the pilot pressure Psol6 applied to the third switching valve 46 is released, and the discharge oil passage 47 is shut off.

  Further, the fourth switching valve 49 is controlled to be in an ON state (step S73). That is, the pilot pressure Psol7 is applied to the fourth switching valve 49 so that the discharge port 33D of the charge pump 33 and the check valve 35, that is, the closed circuit CC are disconnected, and the discharge port 33D of the charge pump 33 is connected to the pressure accumulation oil passage. 48 is communicated.

  Subsequently, the discharge pressure (charge pressure) of the charge pump 33 is an accumulated pressure which is a desired oil pressure when accumulator 45 is accumulated from a normal discharge pressure (PM charge pressure) when supplying pressure oil to the closed circuit CC. The command pressure Ptrg is controlled (step S74). That is, the control target value of the discharge pressure of the charge pump 33 is set to the pressure accumulation command pressure Ptrg. Further, the accumulator pressure PAcc, which is a detection value of the pressure sensor 50 that detects the hydraulic pressure accumulated in the accumulator 45, is read (step S75).

  The discharge oil passage 47 is shut off, and further, the discharge port 33D of the charge pump 33 and the closed circuit CC are shut off and the discharge port 33D communicates with the pressure accumulation oil passage 48, and then the discharge pressure of the charge pump 33 is accumulated. By being controlled to the command pressure Ptrg, the pressure oil discharged from the charge pump 33 is supplied to the accumulator 45 via the pressure accumulation oil passage 48. That is, pressure oil is accumulated in the accumulator 45. FIG. 25 shows a state in which pressure oil is accumulated in the accumulator 45. In this state, the pressure oil discharged from the charge pump 33 is supplied to the accumulator 45 via the pressure accumulation oil passage 48 without being supplied to the closed circuit CC.

  In the closed circuit CC, the second pump motor 13 is driven as a pump in the reverse rotation direction, and the pressure oil sucked from the discharge port 13D of the second pump motor 13 is discharged from the suction port 13S. Then, the pressure oil discharged from the suction port 13 </ b> S is supplied to the first pump motor 12 from the suction port 12 </ b> S side via the oil passage 14. Therefore, the first pump motor 12 is driven as a motor in the forward rotation direction.

  The situation is shown in the alignment chart in FIG. When the vehicle is traveling at a gear ratio between the second speed and the third speed, the second pump motor 13 changes from a state of idling in the reverse rotation direction with the pushing volume q2 being zero to a reaction force from the vehicle. Accordingly, the extrusion volume q2 is controlled, and as the extrusion volume q2 increases, a hydraulic pressure is generated and the reaction force appears on the output shaft.

  In this case, since the second pump motor 13 rotates in the reverse direction, the pressure oil is sucked from the discharge port 13D and discharged from the suction port 13S, and the rotation speed in the reverse rotation direction gradually decreases. This will be described with respect to the second planetary gear mechanism 4. Since the torque from the engine 1 is acting on the ring gear 4R, the torque in the forward rotation direction is acting on the sun gear 4S, and its rotational speed gradually decreases. Torque acts on the carrier 4C in the direction of increasing its rotational speed. The torque of the carrier 4 </ b> C is transmitted to the output shaft 16 via the first synchro 22 and the third speed gear pair 19.

  On the other hand, since the pressure oil discharged from the second pump motor 13 is supplied to the suction port 12S of the first pump motor 12 through the oil passage 14, the first pump motor 12 is driven in the forward rotation direction by the hydraulic pressure. Functions as a motor. That is, power is transmitted from the second pump motor 13 to the first pump motor 12 via hydraulic pressure. As a result, in the first planetary gear mechanism 3, a torque that rotates the sun gear 3S in the forward direction acts on the sun gear 3S, so that the carrier 3C and the first intermediate shaft 8 connected to the carrier 3C are associated with an increase in the rotation speed. The number of rotations increases gradually. The carrier 3C torque is transmitted to the output shaft 16 via the third sync 24 and the second speed gear 18.

  When the pressure oil accumulation in the accumulator 45 is executed, it is determined whether or not the accumulator pressure PAcc is equal to or higher than the accumulation instruction pressure Ptrg (step S76). If the accumulator pressure PAcc is still less than the pressure accumulation command pressure Ptrg and a negative determination is made in step S76, the process returns to step S74, and the previous control is repeatedly executed. That is, the control from step S74 to step S76 is repeated until the accumulator pressure PAcc becomes equal to or higher than the pressure accumulation command pressure Ptrg.

  On the other hand, if the accumulator pressure PAcc is equal to or higher than the pressure accumulation command pressure Ptrg, if the determination in step S76 is affirmative, the process proceeds to step S77, and the pressure accumulation command pressure Ptrg is set in step S74 described above. The discharged discharge pressure of the charge pump 33 is returned to the normal PM charge pressure.

  Then, the fourth switching valve 49 is controlled to be in an OFF state (step S78). That is, the pilot pressure Psol7 applied to the fourth switching valve 49 is released, the discharge port 33D of the charge pump 33 is disconnected from the pressure accumulation oil passage 48, and the discharge port 33D of the charge pump 33 is checked. The valve 35 is connected to the closed circuit CC. Thereafter, this routine is once terminated.

  FIG. 27 is a time chart showing changes in the hydraulic pressure of each part of the hydraulic circuit, the hydraulic pressure of the accumulator 45, and the discharge pressure of the charge pump 33 when the control shown in FIG. 24 is executed. As shown in FIG. 27, at the beginning of the control, the discharge pressure PChp of the charge pump 33 driven by the power of the engine 1 is constant at the PM charge pressure. Similarly, since the pressure oil does not flow in the pressure accumulation oil passage 48 and the discharge oil passage 47 at the beginning of the control, the oil pressure Pd of the pressure accumulation oil passage 48 and the oil pressure Pe of the discharge oil passage 47 are also at a predetermined pressure. It is constant. The hydraulic pressure of the oil passage 15 in the closed circuit CC (that is, the low pressure side hydraulic pressure in the pump motors 12 and 13) Pf and the hydraulic pressure of the oil passage 14 in the closed circuit CC (that is, the high pressure side hydraulic pressure in the pump motors 12 and 13). ) Pg is also almost constant at the initial pressure because no pressurized oil is supplied to the closed circuit CC from the outside.

  In step S73 in the flowchart of FIG. 24, when the fourth switching valve 49 is controlled to be in the ON state, the discharge port 33D of the charge pump 33 and the pressure accumulation oil passage 48 are communicated, and the hydraulic pressure Pd of the pressure accumulation oil passage 48 is charged. It increases to the discharge pressure PChp of the pump 33 (that is, the PM charge pressure in this case).

  In step S74, when the control target value of the discharge pressure of the charge pump 33 is set to the pressure accumulation command pressure Ptrg, the discharge pressure PChp of the charge pump 33 starts to increase toward the pressure accumulation command pressure Ptrg. The oil pressure Pd of the pressure accumulating oil passage 48 through which the increased oil pressure flows and the accumulator pressure PAcc of the accumulator 45 in which the increased oil pressure is accumulated also begin to increase.

  When the discharge pressure PChp and the accumulator pressure PAcc of the charge pump 33 reach the pressure accumulation command pressure Ptrg (step S76), the increase of the discharge pressure PChp of the charge pump 33 is stopped, and then the discharge pressure PChp of the charge pump 33 is decreased in step S77. The hydraulic pressure level at the beginning of the control, that is, the normal PM charge pressure is restored. Along with this, the hydraulic pressure Pd of the pressure accumulating oil passage 48 also decreases to the normal PM charge pressure.

  In step S78, when the fourth switching valve 49 is controlled to be in the OFF state, the discharge port 33D of the charge pump 33 and the pressure accumulation oil path 48 are blocked, and the oil pressure Pd of the pressure accumulation oil path 48 is controlled. Return to the original hydraulic pressure level.

  As described above, according to the control device for a variable displacement fluid pressure pump motor type transmission of the present invention, when accumulating pressure oil in the accumulator 45, the closed circuit CC and the closed circuit CC The charge pump 33 is disconnected, and the charge pump 33 and the accumulator 45 are communicated, and the pressure oil discharged by the charge pump 33 is accumulated in the accumulator 45. Therefore, when accumulating the pressure oil in the accumulator 45, the pressure oil in the closed circuit CC is not affected by the pressure fluctuation due to the discharge of the pressure oil supplied to the accumulator 45 by the charge pump 33. The pressure oil can be quickly accumulated in the accumulator 45 by the charge pump 33 while maintaining the oil pressure in a stable state.

  In addition, when changing the gear ratio across any fixed gear, that is, when performing a shift with a switching operation to switch one of the synchros from the power cut-off state to the power transmission state, in other words, the synchro sleeve When accumulator 45 is connected to oil passage 14 or oil passage 15 of closed circuit CC, pressure is accumulated in accumulator 45. The pressurized oil is supplied to the pump motor 12 (or 13) on the side where the synchro for switching operation is arranged. Then, the rotation of the pump motor 12 (or 13) to which the pressure oil is supplied from the accumulator 45, that is, the rotating shaft 9 connected to the rotor of the pump motor 12 (or 13) so as to rotate integrally or differentially. Alternatively, the direction of synchronizing the rotation of 11) and the rotation of the transmission rotor connected via the gear pair that sets the fixed gear ratio of the transmission gear ratio before and after the fixed gear stage that straddles the output member 16 In addition, the pump motor 12 (or 13) is driven. Therefore, the rotation synchronization between the rotating shaft 9 (or 11) and the transmission rotor can be promoted, and the time required for the movement of the synchro sleeve, that is, the synchro switching operation can be shortened. Even if the shift is performed across gears, the shift time can be shortened and a quick and smooth shift can be executed.

  Then, the pressure oil is accumulated in the accumulator 45 only when the pressure oil in the accumulator 45 decreases and the accumulated pressure becomes lower than the predetermined pressure α. Therefore, when accumulating the pressure oil in the accumulator 45, the pressure fluctuation in the closed circuit CC caused by the charge pump 33 and the closed circuit CC being cut off can be minimized.

  Furthermore, the pressure oil can be accumulated in the accumulator 45 by supplying the pressure oil discharged from the charge pump 33 to the accumulator 45 as described above. Without being provided, the pressure oil is accumulated in the accumulator 45, and the pressure oil accumulated in the accumulator 45 is added to the pressure oil supplied from the charge pump 33 to the closed circuit CC, and the pump motor 12 (or 13). The pump motor 12 (or 13) can be driven. Therefore, the configuration of the transmission can be simplified, and the transmission can be reduced in size and cost.

  The present invention is not limited to the above specific example, and the target transmission may be other than the configuration shown in FIG. 1, for example, in parallel with a transmission mechanism mainly composed of a gear mechanism. A transmission may be provided that is provided with a hydrostatic transmission (HST) so that the entire transmission can be changed continuously. Further, in the example shown in FIG. 1, it is configured to be able to set fixed forward speeds of four forward speeds and one reverse speed, but the transmission targeted by the present invention has a number of fixed gear speeds higher than that. It may be more or less.

  Also, when the pump motor is used as a reaction force mechanism for a differential mechanism such as a single pinion type planetary gear mechanism or a double pinion type planetary gear mechanism, it is a so-called one-way swing type that can increase its pushing volume only in one direction from zero. Not limited to this, a so-called double swing type pump motor that can be changed in both positive and negative directions can also be used. In that case, the gear mechanism may have a configuration different from that shown in FIG.

  Furthermore, the arrangement of transmission mechanisms such as a pump motor, a differential mechanism, and a gear pair can be appropriately changed as necessary, and may be configured to be suitable for a so-called FR vehicle. Furthermore, the power source may be connected to the idle gear of the counter gear pair described above instead of being directly connected to one of the differential mechanisms. Further, a mechanism such as a belt or a chain may be used instead of the gear pair. The power source in the present invention does not have to be an engine, and may be an electric motor or a hybrid drive device that combines an internal combustion engine and an electric motor.

1 is a skeleton diagram schematically showing an example of a transmission according to the present invention. FIG. FIG. 2 is a schematic diagram showing a flow of pressure oil when the transmission shown in FIG. 1 is in a neutral state. It is an alignment chart which shows the operation state of each planetary gear mechanism in a neutral state. It is a flowchart for demonstrating an example of the synchronous control for setting a start stand-by state in a neutral state. FIG. 2 is a chart collectively showing each aspect of synchronous control for the transmission shown in FIG. 1 and a control state of an extrusion volume and a state of pilot pressure in each synchronous control aspect. It is a schematic diagram which shows the operation state of the switching valve and the lock valve when setting the start standby state in the neutral state, and the flow of pressure oil. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing the synchronous control for setting a start standby state in a neutral state. FIG. 5 is a time chart showing changes in oil pressure of each part of the hydraulic circuit when the control shown in the flowchart of FIG. 4 is executed. FIG. It is a flowchart for demonstrating an example of the synchronous control for setting the upshift standby state to 2nd speed. It is a schematic diagram which shows the operation state of the switching valve and the lock valve and the flow of pressure oil when setting the upshift standby state to the second speed. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing the synchronous control for setting the upshift standby state to 2nd speed. It is a flowchart for demonstrating an example of the synchronous control for setting the upshift standby state to the 3rd speed. It is a schematic diagram which shows the operation state of the switching valve and the lock valve when setting the upshift standby state to the third speed and the flow of pressure oil. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing the synchronous control for setting the upshift standby state to the 3rd speed. FIG. 13 is a time chart showing changes in hydraulic pressure of each part of the hydraulic circuit when the control shown in the flowchart of FIG. 12 is executed. It is a flowchart for demonstrating an example of the synchronous control for setting the upshift standby state to 4th speed. It is a schematic diagram which shows the operation state of the switching valve and the lock valve, and the flow of pressure oil when setting the upshift standby state to the fourth speed. It is a flowchart for demonstrating an example of the synchronous control for setting the downshift standby state to 2nd speed. It is a schematic diagram which shows the operation state of the switching valve and the lock valve and the flow of pressure oil when setting the downshift standby state to the second speed. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing the synchronous control for setting the downshift standby state to 2nd speed. It is a flowchart for demonstrating an example of the synchronous control for setting the downshift standby state to 1st speed. It is a schematic diagram which shows the operation state of the switching valve and the lock valve when setting the downshift standby state to the first speed and the flow of pressure oil. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing the synchronous control for setting the downshift standby state to 1st speed. It is a flowchart for demonstrating an example of the control at the time of accumulating pressure oil to an accumulator. It is a schematic diagram which shows the operation state of a switching valve and a lock valve when accumulating pressure oil in an accumulator, and the flow of pressure oil. It is a collinear diagram which shows the operation state of each planetary gear mechanism at the time of performing control at the time of driving | running | working from 2nd speed to 3rd speed and accumulator pressure-accumulating. It is a time chart which shows the change of the oil_pressure | hydraulic of each part of the hydraulic circuit at the time of performing control shown by the flowchart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine (power source, E / G), 2 ... Input member, 3 ... 1st planetary gear mechanism, 4 ... 2nd planetary gear mechanism, 3S, 4S ... Sun gear, 3R, 4R ... Ring gear, 3C, 4C ... Carrier 8 ... first intermediate shaft, 9 ... motor shaft, 10 ... second intermediate shaft, 11 ... motor shaft, 12 ... first pump motor (variable capacity type first fluid pressure pump motor, PM1), 13 ... second Pump motor (variable displacement type second fluid pressure pump motor, PM2), 16 ... output shaft (output member), 14 ... oil passage (first oil passage), 15 ... oil passage (second oil passage), 17 ... 4th gear pair (first transmission mechanism), 18 ... 2nd gear pair (first transmission mechanism), 19 ... 3rd gear pair (second transmission mechanism), 20 ... 1st gear pair (second transmission mechanism), 22 ... 1st synchro (switching mechanism), 23 ... 2nd synchro (switching mechanism), 24 ... 3rd synchronization (switching mechanism), 25 ... R synchronization (switching mechanism), 33 ... Charge pump (supply pump), 39 ... 1st switching valve, 41 ... 2nd switching valve, 43 ... 1st lock valve, 44 ... Second lock valve 45 ... Accumulator (accumulation device) 46 ... Third switching valve 47 ... Discharge oil passage 48 ... Accumulation oil passage 49 ... Fourth switching valve 52 ... Electronic control unit (ECU), CC ... Closed circuit, TM ... Variable displacement hydraulic pump motor type transmission.

Claims (4)

A first power transmission path and a second power transmission path capable of selectively setting a plurality of different gear ratios between the power source and the output member, and torque transmitted through each of the power transmission paths are pushed out. Provided for each of the power transmission paths so as to change in accordance with the volume, and when one of the extrusion volumes is zero, the other is prevented from being supplied and discharged with pressure fluid and locked with each other. A variable displacement first fluid pressure pump motor and a second fluid pressure pump motor whose outlets communicate with each other via a closed circuit; and the first fluid pressure pump motor and the first fluid pressure pump motor are disposed in the first power transmission path; A first transmission mechanism that transmits power from the power source to the output member when the first fluid pressure pump motor is locked, and the second power transmission path along with the second fluid pressure pump motor. And a second transmission mechanism for transmitting power from the power source to the output member when the second fluid pressure pump motor is locked, and transmitting each of the transmission mechanisms to the output member. A switching mechanism that selectively switches between a power transmission state capable of transmitting power and a power shut-off state where power transmission is impossible, and a replenishment pump that supplies pressure fluid to the closed circuit, and shifting each of the transmission mechanisms It is configured to be able to set a fixed shift stage determined by a ratio and a continuously variable transmission state by continuously changing the power transmitted via the pressure fluid between the fluid pressure pump motors. In the control device for the variable displacement fluid pressure pump motor type transmission,
A pressure accumulator capable of accumulating pressure fluid and discharging the accumulated pressure fluid;
The pressure accumulation device and the closed circuit are shut off, the supply pump and the closed circuit are shut off, and the pressure fluid discharged from the supply pump through the supply pump and the pressure accumulation device is communicated to the pressure accumulation device. The pressure fluid accumulated in the pressure accumulating device is communicated with the pressure accumulating state for accumulating and the first oil passage connecting the suction ports of the pressure accumulating device and the closed circuit or the second oil passage connecting the discharge ports with each other. Pressure accumulation control means for selectively setting a discharge state to be discharged into a closed circuit;
When performing a shift with an operation of switching any one of the transmission mechanisms from the power cut-off state to the power transmission state by the switching mechanism, the discharge state is set by the pressure accumulation control means and the power transmission state is set. Shift control means for supplying the accumulated pressure fluid to the fluid pressure pump motor on the power transmission path side where any one of the transmission mechanisms is arranged to drive the fluid pressure pump motor. A control device for a variable displacement fluid pressure pump motor type transmission. The first transmission mechanism and the second transmission mechanism are respectively connected to a rotor of the first fluid pressure pump motor and a rotor of the second fluid pressure pump motor, and to each of the rotation shafts, respectively. A transmission rotating body that is fitted and connected to the rotating shaft to transmit power to the output member, and a plurality of gear pairs that are connected to the respective transmission rotating bodies and have different gear ratios;
The switching mechanism is a synchronous coupling mechanism that achieves the power transmission state by moving a sleeve in an axial direction of the rotation shaft, engaging the transmission rotation body, and connecting the rotation shaft and the transmission rotation body. Including
The shift control means includes means for driving the fluid pressure pump motor in a direction that promotes rotation synchronization between the rotating shaft connected by the synchronous connecting mechanism and the transmission rotating body during the shift. The control apparatus for a variable displacement fluid pressure pump motor type transmission according to claim 1.   The speed change control means supplies the accumulated pressure fluid to any one of the fluid pressure pump motors via the first oil passage, thereby adjusting the rotational speed of the fluid pressure pump motor to the rotation direction of the power source. And the accumulated pressure fluid is supplied to any one of the fluid pressure pump motors via the second oil passage, so that the number of revolutions of the fluid pressure pump motor is increased. 3. The control apparatus for a variable displacement hydraulic pump motor type transmission according to claim 1, further comprising means for increasing in a reverse rotation direction opposite to the rotation direction of the source.   The accumulator control means increases the discharge pressure of the replenishing pump and increases the accumulated pressure when the accumulated pressure of the accumulator is less than a predetermined pressure that is predetermined to maintain the accumulated pressure at a desired pressure level. 4. The variable displacement fluid pressure pump motor type transmission according to claim 1, further comprising means for accumulating the pressure fluid discharged from the replenishing pump by setting the pressure accumulation state in the pressure accumulator. Control device.

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