JP2006316666A - Oil pump - Google Patents

Abstract

To provide an oil pump that can supply pressure oil even when the engine is stopped or at a low speed, and can suppress deterioration in layout and increase in cost.
An engine 1 and a motor 2 are configured such that one oil pump 3 can be driven, and the oil pump 3 is driven by the motor 2 when the engine 1 is stopped as in idle stop control.
[Selection] Figure 1

Description

  The present invention relates to an oil pump that supplies pressure oil.

As this type of technology, a vehicle equipped with an idle stop system that stops the engine when the vehicle is stopped is equipped with two oil pumps, a mechanical pump that operates by engine rotation and an electric pump. Pressure oil is supplied by an electric pump when the engine is running at a low speed (see, for example, Patent Document 1).
JP 2004-286148 A

  However, in the above prior art, since two oil pumps are provided, there are problems such as deterioration in layout and increase in cost.

  The present invention has been made paying attention to the above-mentioned problems, and the purpose of the present invention is to be able to supply pressure oil even when the engine is stopped or when the engine is running at a low speed, and to suppress deterioration in layout and increase in cost. Is to provide an oil pump.

  In order to achieve the above object, according to the present invention, in an oil pump for supplying pressure oil, a first drive means for driving the oil pump by a motor, a second drive means for driving the oil pump by an engine, and an oil pump are provided. And switching means for switching the driving means for driving from the first driving means to the second driving means.

  Thus, it is possible to supply pressure oil even when the engine is stopped or when the engine is running at a low speed, while suppressing deterioration in layout and increase in cost.

  The best mode for carrying out the oil pump of the present invention will be described below with reference to the drawings.

  First, a vehicle equipped with an idle stop system of this embodiment will be described.

  FIG. 1 is an overall system diagram showing a drive system and a control system of a vehicle equipped with an idle stop system.

  A vehicle equipped with an idle stop system includes an engine 1, a motor 2, an oil pump 3 driven by the engine 1 and the motor 2, a forward clutch 4 and a reverse brake that are engaged and released by pressure oil generated by the oil pump 3. 5 and a belt type continuously variable transmission 7 that is speed-controlled by the hydraulic pressure generated by the oil pump 3.

  The engine 1 is connected to an engine output shaft 8 that rotates integrally with the engine rotation. The engine output shaft 8 is connected to a clutch input shaft 10 via a torsional damper 9. Although the rotational fluctuation of the engine 1 is reduced by the torsional damper 9 to the clutch input shaft 10, almost the rotational speed of the engine 1 is input. Therefore, the output shaft of the engine 1 is formed together with the engine output shaft 8. ing. A motor 2 and an oil pump 3 are provided on the clutch input shaft 10.

  The oil pump 3 is driven by the rotational output of the engine 1 transmitted to the clutch input shaft 10 and can be driven by the motor 2. As shown in FIG. 2, a motor 2 and an oil pump 3 are provided coaxially with the clutch input shaft 10. The driven shaft of the oil pump 3 is connected to rotate integrally with the output shaft of the motor 2. 3, the motor 2 is provided on a shaft different from the clutch input shaft 10, and the output shaft of the motor 2 and the driven shaft of the oil pump 3 are connected by a chain 31 or the like. good.

  The driven shaft of the oil pump 3 is connected to the clutch output shaft via the one-way clutch 30. The one-way clutch 30 has, for example, sprags arranged side by side between an outer race and an inner race. The clutch input shaft 10 is inserted into the inner circumference of the inner race and rotates integrally, and an oil pump is provided on the outer circumference of the outer race. 3 driven shafts are fixed so as to rotate integrally. If the relative rotation between the inner race and the outer race of the one-way clutch 30 is the direction in which the sprags stand (lock direction), the inner race and the outer race rotate together. On the other hand, if the relative rotation of the inner race and the outer race of the one-way clutch 30 is in the direction in which the sprag lies down (free direction), the inner race and the outer race can be freely rotated relative to each other. The one-way clutch 30 is configured so that the driving force from the clutch input shaft 10 is not transmitted when the rotational speed of the clutch input shaft 10 is smaller than the rotational speed of the motor 2. The one-way clutch 30 corresponds to the switching means of the present invention.

  The oil pump 3 sucks oil from the oil tank 12 to generate pressure oil. The pressure oil is adjusted to the line pressure by the line pressure control unit 13 and supplied to a device that operates by oil pressure.

  The forward / reverse switching mechanism 6 includes a forward clutch 4 and a reverse brake 5, and a simple planetary gear 11. The forward clutch 4 and the reverse brake 5 can be switched between a fastening state in which the plate is pressed by applying pressure oil to a piston (not shown) and a release state in which the pressing force of the plate is released by discharging the pressure oil from the piston. Composed. For the piston, the pressure oil whose pressure has been adjusted to the line pressure by the line pressure control unit 13 is adjusted to the hydraulic pressure by the clutch pressure control unit (not shown) according to the engagement pressure control of the forward clutch 4 or the reverse brake 5. Oil is supplied.

  The simple planetary gear 11 rotatably supports a sun gear 11s that rotates concentrically with the clutch output shaft 14, a plurality of pinions 11p that mesh with the outer periphery of the sun gear 11s, a ring gear 11r that meshes with the pinion 11p, and the pinion 11p. Carrier 11c. The sun gear 11s is connected to the driven side portion of the forward clutch 4 and the clutch output shaft 14, the carrier 11c is connected to the fixed side portion of the reverse brake 5, and the ring gear 11r is connected to the drive side portion of the forward clutch 4. Yes.

  The belt type continuously variable transmission 7 includes a primary pulley 15 connected to the clutch output shaft 14, a secondary pulley 17 connected to the transmission output shaft 16, and a CVT spanned between the primary pulley 15 and the secondary pulley 17. Belt 18. The primary pulley 15 and the secondary pulley 17 have fixed sheaves 15a and 17a and movable sheaves 15b and 17b that approach and separate from the fixed sheaves 15a and 17a, respectively. A primary pulley oil chamber 19 and a secondary pulley oil chamber 20 are provided on the back surfaces of the movable sheaves 15 b and 17 b of the primary pulley 15 and the secondary pulley 17. The primary pulley oil chamber 19 is supplied with the pressure oil adjusted to the line pressure by the line pressure control unit 13 and the pressure oil adjusted according to the shift control by the shift hydraulic control unit 21. The secondary pulley oil chamber 20 is supplied with pressure oil adjusted to the line pressure. By supplying the primary pulley oil chamber 19 with the pressure oil adjusted according to the shift control, the movable sheaves 15b and 17b of the primary pulley 15 and the secondary pulley 17 are displaced, and the rotation radius of the CVT belt 18 is increased. It is configured to be capable of changing continuously.

  An output gear 22 is fixed to the end of the transmission output shaft 16 on the secondary pulley 17 side of the belt type continuously variable transmission 7, and meshed with a drive gear 23 having a larger diameter than the output gear 22.

  Two pinions of a differential gear 24 are fixed to the drive gear 23, and side gears are engaged with these pinions from the left and right, respectively. A drive shaft 25 is connected to each side gear so as to drive the left and right drive wheels 26.

  Further, as a control system, the engine control device 27 that controls the engine 1, the idle stop control device 28 that performs idle stop control, and the control signals of the engine control device 27 and the idle stop control device 28 are integrated into the engine 1 and the like. And an integrated control device 29 for controlling.

  Next, the operation will be described.

[Idle stop control]
The idle stop control device 28 starts idle stop control for stopping the engine 1 when the driver's intention to stop the vehicle can be determined based on, for example, a condition that the driver stops the vehicle while operating the brake. . On the other hand, after the start of the idling stop control, when the driver's intention to start the vehicle can be determined by conditions such as releasing the brake, the engine 1 is restarted and the idling stop control is terminated.

[Operation of oil pump]
In the case of an oil pump driven only by the engine 1, the engine 1 is stopped during the idle stop control, so that the oil pump is also stopped and pressure oil cannot be supplied. Therefore, during the idle stop control, the pressure oil acting on the pistons of the forward clutch 4 and the reverse brake 5 and the primary pulley oil chamber 19 and the secondary pulley oil chamber 20 is lost. When the engine 1 is restarted, pressure oil is started to be supplied to the pistons of the forward clutch 4 and the reverse brake 5, the primary pulley oil chamber 19 and the secondary pulley oil chamber 20, but it takes time until the oil is filled. Sometimes there is a possibility that smooth start response cannot be obtained.

  The above problem can be solved by newly providing an oil pump driven by the motor 2 in addition to the oil pump driven by the engine 1 so that the pressure oil can be supplied even when the engine is stopped or at a low speed. In addition, it is necessary to provide two oil pumps, which deteriorates the layout. Further, since the oil pump driven by the motor 2 is driven only when the engine 1 is stopped or the engine 1 is rotating at a low speed, the utilization efficiency is low and the cost is increased.

  Therefore, in this embodiment, one oil is used for both the driving of the oil pump 3 by the motor 2 as the first driving means in the present invention and the driving of the oil pump 3 by the engine 1 as the second driving means in the present invention. The pump 3 can be driven. As a result, the oil pump 3 can be driven by operating the motor 2 when the engine 1 is stopped or rotating at a low speed.

  Further, the inertia energy of the oil pump 3 of this embodiment is much smaller than the drive system inertia energy of the vehicle, and the motor 2 is designed to drive the oil pump 3 and is a low output motor. . Therefore, when the inertia energy on the drive side is transmitted to the oil pump 3, the load is too large, and the motor 2 cannot drive the oil pump 3.

  On the other hand, when the rotational speed of the engine 1 is larger than the rotational speed of the motor 2, the driving force is transmitted from the clutch input shaft 10 to the oil pump 3 by the action of the one-way clutch 30.

  Therefore, a one-way clutch 30 is provided between the oil pump 3 and the clutch input shaft 10. When the oil pump 3 is driven by the motor 2 when the engine 1 is stopped or at a low rotation speed, the drive side inertia energy is not transmitted to the oil pump 3 by the one-way clutch 30. Therefore, since the load from the drive side is not transmitted to the oil pump 3, the motor 2 can drive the oil pump 3.

  Further, when the rotational speed of the engine 1 becomes sufficiently larger than the rotational speed of the motor 2, the motor 2 is stopped to save power.

  In this embodiment, the one-way clutch 30 is provided only between the engine 1 and the oil pump 3, but a one-way clutch may be provided between the motor 2 and the oil pump 3. As a result, when the oil pump 3 is driven by the engine 1, the inertia energy of the motor 2 is not transmitted to the oil pump 3 side, so the load on the engine 1 side can be reduced.

  FIG. 4 shows a time chart for increasing the rotational speed of the oil pump 3.

  At time t0, idle stop control is started. When the engine 1 is stopped, the motor 2 operates and the oil pump 3 is driven by the motor 2.

  From time t0 to time t1, since the engine 1 is stopped by the idle stop control, the motor 2 drives the oil pump 3 at the rotational speed N1.

  At time t1, the idle stop is completed and the engine 1 is restarted. Until the time t2, the rotational speed of the engine 1 is smaller than the rotational speed N1 of the motor 2, so that the relative rotation between the inner race and the outer race of the one-way clutch 30 rotates in the free direction. At this time, the driving force from the engine 1 to the oil pump 3 is not transmitted, and the oil pump 3 is continuously driven by the motor 2.

  When the rotational speed of the engine 1 becomes larger than the rotational speed N1 of the motor 2 at time t2, the relative rotation between the inner race and the outer race of the one-way clutch 30 rotates in the locking direction. At this time, the driving force is transmitted from the engine 1 to the oil pump 3, and thereafter, the oil pump 3 is driven by the engine 1, and the motor 2 is stopped at time t3 when the rotational speed of the engine 1 is sufficiently increased.

  Next, the effect of the present embodiment will be described.

  (1) One oil pump 3 can be driven by the engine 1 and the motor 2. Therefore, the oil pump 3 that is normally driven by the engine 1 can be driven also by the motor 2, and space can be saved as compared with the case where an oil pump is provided, and the frequency of use of the oil pump 3 is also possible. Therefore, the layout can be improved and the cost can be reduced.

  (2) When the rotational speed of the engine 1 is larger than the rotational speed of the motor 2 by the one-way clutch 30, the oil pump 3 can be driven by the engine 1, so that the oil pump 3 is driven by the motor 2 instead of driving the oil pump 3. High output driving force can be input. Therefore, a higher pressure can be generated by driving the oil pump 3 by the engine 1.

  (3) The one-way clutch 30 is used as a clutch for switching between transmission and non-transmission of driving force from the engine 1 side to the oil pump 3. Therefore, transmission or non-transmission of the driving force from the engine 1 side to the oil pump 3 can be automatically switched according to the differential rotational speed between the engine 1 and the motor 2 without providing a control device or the like.

  (4) Since the motor 2 is stopped when the rotational speed of the engine 1 becomes sufficiently large, power saving can be achieved.

  (5) Since the oil pump 3 can be driven by the motor 2 when the engine 1 is stopped as during idle stop control, sufficient pressure oil can be supplied into the hydraulic circuit. Therefore, it is possible to prevent the pressure oil acting on the pistons of the forward clutch 4 and the reverse brake 5 and the primary pulley oil chamber 19 and the secondary pulley oil chamber 20 from escaping even during the idle stop control. Therefore, even when the engine 1 is restarted, the hydraulic control is started from the state in which the pistons of the forward clutch 4 and the reverse brake 5 and the primary pulley oil chamber 19 and the secondary pulley oil chamber 20 are filled with oil. Responsiveness can be obtained.

  (6) When the rotational speed of the motor 2 is larger than the rotational speed of the engine 1, the oil pump 3 can be driven by the motor 2. Therefore, it is possible to prevent the pressure oil acting on the pistons of the forward clutch 4 and the reverse brake 5 and the primary pulley oil chamber 19 and the secondary pulley oil chamber 20 from escaping even during the idle stop control. Further, even when the rotation speed of the engine 1 is low so that the oil pump 3 cannot be driven sufficiently, driving the oil pump 3 with the oil pump 3 can generate a sufficient hydraulic pressure. Therefore, smooth start response can be obtained even when the vehicle restarts.

  (7) The oil pump 3 is provided coaxially with the clutch input shaft 10 constituting the output shaft of the engine 1. Therefore, when it is mounted on a vehicle having a small space outside the clutch input shaft 10 in the radial direction, the layout can be improved.

  (8) The motor 2 is provided coaxially with the clutch input shaft 10 constituting the output shaft of the engine 1. Therefore, when it is mounted on a vehicle having a small space outside the clutch input shaft 10 in the radial direction, the layout can be improved.

  (9) Since the motor 2 is provided on a shaft different from the clutch input shaft 10 and the output shaft of the motor 2 and the driven shaft of the oil pump 3 are connected by the chain 31, the shaft of the clutch input shaft 10 When the vehicle is mounted on a vehicle in which the direction length can be shortened and the space in the axial direction of the clutch input shaft 10 is small, the layout can be improved.

  Although the oil pump of the present invention has been described based on the first embodiment, the specific configuration is not limited to this embodiment, and departs from the gist of the invention according to each claim of the claims. Unless otherwise, design changes and additions are permissible.

  For example, in the first embodiment, the one-way clutch 30 is provided between the clutch input shaft 10 and the driven shaft of the oil pump 3, but the differential rotational speed between the engine 1 and the motor 2 is calculated to obtain the clutch input shaft. An electromagnetic clutch or the like for connecting / disconnecting the motor 10 and the driven shaft of the oil pump 3 may be provided.

  In Example 1, the oil pump of the present invention is not limited to a vehicle equipped with a belt-type continuously variable transmission, but also a vehicle equipped with a stepped transmission, a vehicle equipped with a toroidal continuously variable transmission, a vehicle equipped with an automatic MT, a hybrid vehicle, and an electric vehicle. In short, the present invention can be applied to various vehicles that include a device that performs hydraulic control and includes an oil pump that supplies pressure oil to the device.

1 is an overall system diagram showing a drive system and a control system of a vehicle equipped with a belt type continuously variable transmission. It is a figure which shows the structure which provides an oil pump and a motor on the same axis | shaft of a clutch input shaft. It is a figure which shows the structure which provides a motor on a different shaft from a clutch input shaft. It is a time chart which shows switching of the drive of the oil pump by an engine or a motor.

Explanation of symbols

1 Engine 2 Motor 3 Oil pump 10 Clutch input shaft 30 One-way clutch

Claims (9)

In an oil pump that supplies pressurized oil,
First driving means for driving the oil pump by a motor;
Second driving means for driving the oil pump by an engine;
Switching means for switching the drive means for driving the oil pump from the first drive means to the second drive means;
An oil pump comprising: The oil pump according to claim 1, wherein
The oil pump according to claim 1, wherein the switching means switches to the second driving means when the rotational speed of the engine is larger than the rotational speed of the motor. In the oil pump according to claim 1 or 2,
The oil pump according to claim 1, wherein the switching means is a one-way clutch provided between the engine and the oil pump. The oil pump according to any one of claims 1 to 3,
The oil pump according to claim 1, wherein the switching means stops the motor when the rotational speed of the engine becomes larger than the rotational speed of the motor. The oil pump according to claim 1, wherein
The switch means switches the drive means for driving the oil pump from the second drive means to the first drive means. In the oil pump according to claim 5,
The oil pump according to claim 1, wherein the switching means switches from the second driving means to the first driving means when the rotational speed of the motor is larger than the rotational speed of the engine. The oil pump according to claim 1, wherein
The oil pump is provided on the same axis as an output shaft of the engine. The oil pump according to claim 1, wherein
The oil pump is characterized in that the motor is provided coaxially with the output shaft of the engine. The oil pump according to claim 1, wherein
The oil pump is characterized in that the motor is provided on a shaft different from the output shaft of the engine.

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