JP2001349342A - Automatic transmission - Google Patents

Abstract

[PROBLEMS] To reduce the size and weight of an automatic transmission for a vehicle having a friction engagement element such as a clutch or a brake. SOLUTION: This automatic transmission has a clutch hub 42 on which a plurality of clutch discs 47 are mounted on the outside, and a clutch drum 43 on which a plurality of clutch discs 48 frictionally engaged with the clutch discs 47 are mounted on the inside. And
A piston drum 52 having a larger diameter than the clutch disks 47 and 48 is fixed between the clutch shaft 43 and the hollow shaft portion 51 having a smaller diameter than the clutch hub 42. A piston 53 is provided in the piston drum 52 so as to be movable in the axial direction, and a piston oil chamber 5 is provided in the piston drum 52.
4, and a cancel oil chamber 58 is formed radially outward of the piston oil chamber 54 by a retainer 57 disposed between the outer peripheral surface of the piston and the piston drum 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle having a friction engagement element such as a clutch or a brake.

[0002]

2. Description of the Related Art An automatic transmission, that is, an automatic transmission, has a plurality of planetary gear mechanisms and a plurality of clutches and brakes for turning them on and off, respectively, and by controlling a hydraulic circuit according to a throttle opening and a vehicle speed. The shift operation according to the running state is automatically performed.

[0003] The clutch has a clutch hub fixed to an inner rotating member and a clutch drum fixed to an outer rotating member. A plurality of clutch discs attached to the clutch hub and attached to the clutch drum. When the plurality of clutch discs are frictionally engaged, both rotating members are in a connected state, and when the respective clutch discs are slid, the connection of the rotating members is released.

In order to frictionally disengage and disengage both clutch discs, a piston is incorporated in the clutch drum, and the piston presses the clutch disc by hydraulic pressure supplied to a piston oil chamber. It has become. When the rotation shaft is driven to rotate, the piston oil chamber also rotates, so that centrifugal force also acts on the hydraulic oil in the piston oil chamber. In order to offset this centrifugal force, for example, as disclosed in JP-A-9-32919, a cancel oil chamber may be provided on the opposite side of the piston.

[0005]

However, when the piston oil chamber is provided on one side of the piston and the cancel oil chamber is provided on the other side, the axial dimension of the power train becomes longer, and the automatic transmission is changed. There is a problem that the size of the machine cannot be avoided. Further, as disclosed in the above publication, a clutch having a dual structure on the inner side and the outer side, and when the outer diameter of the outer piston is larger than that of the inner clutch disc, the inner clutch drum is provided. Since the shape of the outer piston and the shape of the outer piston become complicated and the pressing force of the piston that operates the inner clutch cannot be increased, the clutch capacity can be increased only by increasing the number of multi-plate clutch discs. The extension of the power train leads to an increase in size and weight.

An object of the present invention is to achieve a reduction in size and weight of an automatic transmission for a vehicle having a friction engagement element such as a clutch or a brake.

[0007]

According to the present invention, there is provided a clutch hub having a plurality of clutch discs mounted on the outside thereof, and a clutch drum having a plurality of clutch discs mounted thereon for frictionally engaging the clutch discs. An automatic transmission for intermittently connecting and disconnecting power between the clutch hub and the clutch drum, wherein the automatic transmission is fixed between a hollow shaft portion having a smaller diameter than the clutch hub and the clutch drum, and has a larger diameter than the clutch disc. A piston drum having an outer peripheral surface smaller in diameter than the inner diameter of the piston drum, the piston drum being provided movably in the axial direction within the piston drum, and forming a piston oil chamber between the piston drum and an end wall of the piston drum A cancel oil chamber is disposed between the outer peripheral surface of the piston and the inner peripheral surface of the piston drum, and is formed radially outward of the piston oil chamber. And a retainer for, characterized in that provided radially outward relative to the piston oil chamber the cancel oil chamber. In the present invention, since the cancel oil chambers are provided concentrically outside the piston oil chambers, the size and weight of the clutch mechanism including the respective oil chambers can be reduced.

In the automatic transmission according to the present invention, the clutch drum has a cylindrical portion and a flange portion protruding outward from the cylindrical portion, and a sealing member is fired on the flange portion to seal the piston drum. It is characterized by being joined. According to the present invention, it is possible to provide a canceling mechanism for canceling the centrifugal hydraulic pressure without extending the axial dimension, thereby shortening the overall length of the transmission, and achieving lightening and miniaturization thereof. it can.

The automatic transmission according to the present invention is characterized in that the piston is provided with a communication hole communicating with the cancel oil chamber. According to the present invention, the oil pressure of the cancel oil chamber can be arbitrarily set.

In the automatic transmission according to the present invention, a lubricating oil supply hole for supplying lubricating oil to the clutch disk is formed in the piston. According to the present invention, the clutch disk can be lubricated, and the durability of the clutch can be improved.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a skeleton diagram showing an automatic transmission according to an embodiment of the present invention. This automatic transmission is composed of a torque converter 11, a main transmission section 12, and an auxiliary transmission section 1.
3, which are incorporated in the transmission case 14.

The torque converter 11 has a drive plate 16 connected to the crankshaft 15 of the engine and rotating, and a pump side case 17 connected to the drive plate 16. A pump impeller provided in the pump side case 17 is provided. Turbine runner 1 arranged opposite to 18
9 is directly connected to the turbine shaft 21. A stator 22 is arranged between the pump impeller 18 and the turbine runner 19, and the stator 22 is supported by a one-way clutch 23.

The front cover 2 is attached to the turbine runner 19.
4 is provided, and one side of the lock-up clutch 25 is connected to the apply chamber 2.
6a and the other side is a release chamber 26b. By circulating the hydraulic pressure supplied into the release chamber 26b through the apply chamber 26a, the torque converter 11 is activated. On the other hand, when the hydraulic pressure is supplied to the apply chamber 26a to lower the hydraulic pressure in the release chamber 26b, the lock-up clutch 25 is engaged with the front cover 24 to be in a lock-up state.

The main transmission section 12 has a structure in which the rotation of the turbine shaft 21 is automatically shifted from the first speed to the fourth speed, and is rotated backward and transmitted to the intermediate shaft 27. A clutch drum 32 having a larger diameter is disposed outside the clutch drum 31, and a reverse clutch ReC is provided between the clutch drums 31 and 32, and the clutch drum 32 is provided inside the clutch drum 32. A high clutch HC is provided between the provided clutch hub 33 and the clutch drum 31.

The clutch drum 32 includes a brake hub 34.
Is fixed and the front sun gear S_FIs fixed
This sun gear S_FOutside the front ring gear R
_FAre provided, and a key fixed to the clutch hub 33 is provided.
Carrier 35 has a sun gear S_FAnd ring gear R_FTo bite
Meet planetary gear P_FIs rotatably mounted
You. A rear sun gear S is provided on the turbine shaft 21._RIs fixed
And this sun gear S_ROutside the rear ring gear R_R
Are arranged, and the ring gear R_FCarry fixed to
A 36 has a sun gear S_RAnd ring gear R_RMesh with
U planetary gear P _RIs rotatably mounted.

Between the brake hub 34 and the case 14, the brake 2 which is engaged at the second, fourth and fifth speeds
・ 4B is provided. The clutch drum 37 is fixed to the carrier 35, the low clutch LC is provided between the clutch hub 38 and the clutch drum 37 fixed to the ring gear R _R.

A brake hub 39 is provided on the clutch drum 37.
The low and reverse brakes LRB are provided between the brake hub 39 and the case 14, and the clutch drum 37 is rotatably supported by the case 14 via a one-way clutch FL.

The auxiliary transmission section 13 is structured to be transmitted to the output shaft 28 as a directly connected state or decelerating the rotation of the intermediate shaft 27, intermediate shaft 27 is fixed to the output side ring gear R _O, the ring gear R _O In the center of the output sun gear S
_O is arranged, the planetary gear P _O meshing with the ring gear R _O and the sun gear S _O is provided rotatably on the output side carrier 41 fixed to the output shaft 28.

The clutch hub 4 fixed to the carrier 41
A direct clutch DC is provided between the clutch drum 43 and the clutch drum 43 fixed to the sun gear S _O , and a reduction brake RB is provided between the clutch drum 43 and the case 14.

Each of the clutches and brakes described above has a plurality of annular inner disks mounted on an inner member such as a clutch hub so as to be slightly movable in the axial direction, and a plurality of shafts mounted on outer members such as a clutch drum and a case. A plurality of annular outer disks mounted slightly movably in the direction, and when the inner disk and the outer disk are frictionally engaged by tightly contacting each other, the inner member and the outer member are connected. It will be in the state that was done. On the other hand, when the fastening force is released, the engaged state is released and the connection between the two members is disconnected. The setting of the state in which the tightening force is applied to the disk as the frictional engagement element and the state in which the tightening force is released are performed by a hydraulic piston. The operation of each hydraulic piston is performed by a hydraulic pressure generated by a hydraulic pump 29 driven directly by the crankshaft 15.

FIG. 2 is a skeleton diagram showing the power transmission path of the speed change element shown in FIG. 1, and FIG. 3 shows the relationship between the intermittent state of each friction engagement element shown in FIGS. 1 and 2 and the speed ratio. FIG. 3 is an operation table shown in FIG. 3, in which a circle indicates a fastened state in which each friction engagement element is turned on, that is, frictionally engaged.

As shown in FIGS. 2 and 3, when the reduction brake RB is on, the rotation of the intermediate shaft 27, which is the output shaft of the main transmission unit 12, is reduced by the auxiliary transmission unit 13 to the output shaft 28. Will be output. On the other hand, when the reduction brake RB is off and the direct clutch DC is on, the intermediate shaft 27
Will be output directly.

For example, when shifting to the first speed, FIG.
As shown in FIG. 7, the low clutch LC, the low and reverse brakes LRB and the reduction brake RB are set to ON, and the rotation of the turbine shaft 21 is caused by the revolving of the planetary gears P _R and P _O by the revolution of the sun gears S _R and S _O. 28.

As shown in FIG. 3, by operating the respective clutches and brakes, the shift control of the fifth forward speed is automatically performed according to the running state.

FIG. 4 is a sectional view showing the details of the sub-transmission portion 13. The carrier 41 is fixed to the output shaft 28 by a spline 44, and the planetary gear _PO is supported by a support shaft 45 fixed to the carrier 41. Is rotatably mounted via a bearing 46. A plurality of annular clutch disks 47 are mounted outside the clutch hub 42 fixed to the carrier 41 so as to be slightly movable in the axial direction. On the other hand, a plurality of annular clutch disks 48 are mounted inside the clutch drum 43 fixed to the sun gear S _O so as to be slightly movable in the axial direction, and the respective clutch disks 47 and 48 are alternately arranged. Are located.

The clutch drum 43 has a flange portion 43b projecting radially outward to the end portion and the cylindrical portion 43a, the clutch drum 43 engages portion 5 to the sun gear S _o
1a, and a cylinder or piston drum 52 fixed to an end of the hollow shaft 51.
And is fixed to the sun gear S _O through.

The piston drum 52 has a large-diameter portion 52a, a small-diameter portion 52b, and an end wall 52c.
7, 48 are set larger than the outer diameter. A piston 53 is provided in an annular space defined by the piston drum 52 and the hollow shaft portion 51 so as to be movable in the axial direction. The piston 53 has a small-diameter portion 53a smaller in diameter than the clutch hub 42, A large-diameter portion 53b having an intermediate diameter between the inner diameter of the clutch drum 43 and the outer diameter of the clutch hub 42 is provided, and a partition wall 53c is provided therebetween. Projecting flange 5
3d is provided.

The rear end face of the piston 53 and the piston drum 5
2, a piston oil chamber 54 is provided in the piston drum 52.
Is formed, and when hydraulic pressure is supplied into the piston oil chamber 54 through an oil passage 55a formed in the case 14, the piston 5
4 is driven to the left in FIG. 4, and the clutch disks 47 and 48 are pressed by the large-diameter portion 53b to come into close contact with each other to be in a frictional engagement state. When the pressurization of the piston oil chamber 54 is stopped, the piston 53 is returned to the right by the spring force of the return coil spring 56, and the clutch disks 47 and 48 are disengaged from the engaged state.

An inner peripheral surface of a flange portion 43c protruding inward from an end of the clutch drum 43 has a piston 53
And a retainer 57 is disposed between the outer peripheral surface of the piston 53 and the inner peripheral surface of the piston drum 52. The retainer 57 is fixed to the outer peripheral surface of the piston 53 by sealing at the inner peripheral portion, and the seal portion provided on the outer peripheral portion is slidably in contact with the inner peripheral surface of the piston drum 52. A cancel oil chamber 58 is formed between the clutch oil chamber and the end of the clutch drum 43.

Therefore, when the clutch drum 43 and the piston drum 52 rotate, the centrifugal oil pressure is applied to the hydraulic oil in the piston oil chamber 54 by the centrifugal force, and the centrifugal oil pressure acts in the direction of tightening the clutch disc. The centrifugal oil pressure is offset by the centrifugal oil pressure applied to the hydraulic oil in the cancel oil chamber 58 by the centrifugal force. Thereby, the operation accuracy of the direct clutch DC can be improved.

As described above, the cancel oil chamber 58 is not provided in the piston oil chamber 54 in the axial direction, but is provided concentrically outward in the radial direction.
The centrifugal oil pressure generated in the piston oil chamber 54 can be canceled by the cancel oil chamber 58 without increasing the axial dimension of the transmission, even if the diameter of the clutch disc 2 is set larger than the outer diameter of the clutch disks 47 and 48. This makes it possible to achieve a reduction in the size and weight of the clutch mechanism and an increase in hydraulic control accuracy.

As shown in FIG. 4, a communication hole 59 communicating with the cancel oil chamber 58 is formed in the partition wall 53c of the piston 53.
The communication hole 59 is communicated with the oil passage 55b. By changing the number and diameter of the communication holes 59, the cancel oil chamber generated in the cancel oil chamber 58 can be arbitrarily set. .

The small diameter portion of the piston 53 has a lubricating oil supply hole 6
1 is formed, and a lubricating oil supply hole 62 is formed in the clutch hub 42 in correspondence with the supply hole 61, and the lubricating oil supply holes 61, 62 leak from an oil passage communicating with the cancel oil chamber 58. Guide oil to clutch hub 42.
As a result, the hydraulic oil leaking from the oil passage is supplied to the lubricating oil
The lubricating oil is supplied to the clutch disks 47 and 48 via the lubricating gears 1 and 62, so that the multi-plate clutch portion can be stably lubricated and the durability of the direct clutch DC can be improved.

A brake disk 63 made of the same member as the clutch disk is mounted on the outside of the clutch drum 43, and a brake disk 64 is mounted on the inside of the case 14 alternately with the brake disk 63. , 64 with reduction brake R
B is formed. An annular brake piston 65 is provided in the case 14, and when hydraulic pressure is supplied to the oil chamber 66, a dog 67 provided at the tip of the brake piston 65 presses the disks 63 and 64, and the reduction brake RB is in a frictionally engaged state. Is set. Since the oil chamber 66 is provided in the case 14, the hydraulic oil in the oil chamber 66 does not generate centrifugal oil pressure, and when the supply of the oil pressure to the oil chamber 66 is stopped,
The spring piston 68 returns the brake piston 65.

FIG. 5 is an enlarged perspective view showing a part of the clutch drum 43 and the piston drum 52. The teeth and grooves are formed in the flange portion 43b of the clutch drum 43, and the large-diameter portion 52a of the piston drum 52 is formed. The corresponding teeth and grooves are formed, and a seal member is baked on one of the meshing portions, and is assembled in a liquid-tight manner and joined. As a result, the clutch drum 43 and the piston drum 52 are joined in a sealed state, and it is possible to reliably prevent the operating oil in the cancel oil chamber 58 from leaking from this joint.

The present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the invention.

For example, FIG.
Although the case where the present invention is applied to the direct clutch DC portion is shown, the present invention may be applied to other clutches.

[0039]

According to the present invention, since the cancel oil chamber is formed radially outward of the piston oil chamber for applying oil pressure to the piston for operating the friction engagement element, the axial direction of the transmission is reduced. The size can be shortened, and the size and weight of the clutch mechanism can be reduced.

The centrifugal hydraulic pressure can be canceled even in a clutch mechanism having a piston drum larger in diameter than the clutch disk, so that the hydraulic control accuracy can be improved.

Since the flange portion of the clutch drum and the piston drum are sealed and joined by firing, the axial length of the clutch mechanism can be suppressed while maintaining the sealing property of the hydraulic oil. Thus, the axial dimension of the clutch mechanism can be reduced.

By communicating the communication hole with the cancel oil chamber, the centrifugal oil pressure generated in the cancel oil chamber can be set to an arbitrary pressure.

Since lubricating oil is supplied to the clutch disk from the lubricating oil supply hole, the clutch disk can be stably lubricated, and the durability of the clutch can be improved.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a skeleton diagram showing a power transmission path of the speed change element shown in FIG.

FIG. 3 is an operation table showing a relationship between an intermittent state of a friction engagement element and a gear ratio.

FIG. 4 is a sectional view showing details of a subtransmission unit.

FIG. 5 is an enlarged perspective view showing a part of a clutch drum and a piston drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Torque converter 12 Main transmission part 13 Sub transmission part 14 Transmission case 41 Carrier 42 Clutch hub 43 Clutch drum 43a Cylindrical part 43b Flange part 47, 48 Clutch disk 51 Hollow shaft part 52 Piston drum 53 Piston 54 Piston oil chamber 58 Cancel Oil chamber 59 Communication hole 61, 62 Lubricating oil supply hole

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3J057 AA04 BB04 CA03 CA11 DA06 DC10 EE05 GA03 GA11 GA12 GD14 3J063 AA01 AB53 AC04 BA11 CA01 CB06 CD13 CD17 CD24 XD03 XD23 XD43 XD62 XD72 XD73 XE15

Claims (4)

[Claims] 1. A clutch hub having a plurality of clutch discs mounted on an outer side, and a clutch drum having a plurality of clutch discs mounted on the inner side frictionally engaged with the clutch discs, wherein the clutch hub and the clutch are provided. An automatic transmission for interrupting power to and from a drum, wherein the piston is fixed between a hollow shaft portion having a smaller diameter than the clutch hub and the clutch drum, and has a larger diameter than the clutch disk. A piston having an outer peripheral surface having a diameter smaller than the inner diameter of the drum, provided movably in the axial direction within the piston drum, and forming a piston oil chamber with an end wall of the piston drum; A retainer disposed between the piston drum inner peripheral surface and a cancel oil chamber radially outward of the piston oil chamber. An automatic transmission, wherein the cancel oil chamber is provided radially outward with respect to the piston oil chamber. 2. The automatic transmission according to claim 1, wherein
The automatic transmission according to claim 1, wherein the clutch drum has a cylindrical portion and a flange portion protruding outward from the cylindrical portion, and a seal member is fired on the flange portion and sealed and joined to the piston drum. . 3. The automatic transmission according to claim 1, wherein the piston is provided with a communication hole communicating with the cancel oil chamber. 4. The automatic transmission according to claim 1, wherein a lubricating oil supply hole for supplying lubricating oil to the clutch disk is formed in the piston. Transmission.