JP3630728B2 - Friction engagement device capable of mechanical synchronization - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a friction engagement device used for a transmission for a vehicle or a transmission for an industrial machine or a construction machine.
[0002]
[Prior art]
For example, the frictional engagement device 510 of the vehicle automatic transmission includes a mating plate 516 that is spline-fitted to the drum 512 in a cylindrical space between the drum 512 and the hub 514 that rotate relative to each other, as shown in FIG. A clutch plate 518 that is spline-fitted to the hub 514 is provided. A retaining plate 522 that is prevented from moving in the axial direction by the snap ring 520 is spline-fitted to the drum 512 on one side in the axial direction of the plate groups 516 and 518. A piston 526 that forms an oil chamber 524 with the drum 512 is provided on the other side in the axial direction of the plate groups 516 and 518. When oil is supplied to the oil chamber 524, the piston 526 operates in the axial direction, and the plate groups 516 and 518 are frictionally engaged between the retaining plate 522 and the piston 526. As a result, torque is transmitted from the drum 512 to the hub 514 or from the hub 514 to the drum 512.
The friction engagement device may be provided in the transmission as a brake between the housing and the drum.
[0003]
[Problems to be solved by the invention]
With the recent technological breakthrough, when the engine performance of automobiles improves, the performance improvement of the friction engagement device is required accordingly, and how to increase the transmission torque capacity becomes a problem. This problem can be generally solved by increasing the hydraulic pressure acting on the piston, increasing the pressure receiving area of the piston, increasing the diameter of the plate group, or increasing the number of plate groups.
[0004]
However, in such a solution, there is a problem that the power loss of the hydraulic pump becomes significant and the transmission efficiency of the hydraulic equipment is reduced, and the transmission is enlarged due to an increase in the component size, an increase in the number of components, and the like.
[0005]
[Means for Solving the Problems]
Accordingly, an object of the present invention is to provide a friction engagement device capable of mechanically coupling both members after the relative rotating members are synchronized. The present invention includes two members that rotate relative to each other and form a cylindrical space therebetween, a plate group that is spline-fitted to each of the members in the cylindrical space, and a single axial direction of the plate group. The plate group is frictionally engaged between a retaining plate disposed on one of the members on the side and the retaining plate disposed on one of the members on the other axial side of the plate group. A friction engagement device having a hydraulically operated piston has the following characteristics.
[0006]
In the present invention, firstly, a cam plate whose rotation is not restrained with respect to the member between the retaining plate and the plate group, a spring for separating and biasing the retaining plate and the cam plate, A synchronizing plate having spline teeth that are spline fitted to one of the members between the piston and the plate group and spline fitted to the other spline of the member when the piston is operated, and the retaining plate; The cam plate is opposed to a cam surface formed so that the axial thickness increases or decreases in the circumferential direction, and the synchronization plate is urged toward the piston by the spring when the piston is not operated. No spline fitting with the other of the members, and when the piston is operated, the synchronization plate is fitted with the other of the members with the spline. It solved the problems by frictional engagement device for.
[0007]
Secondly, the present invention includes a cam plate whose rotation is not restricted with respect to the member on the piston side of the plate group, and a spline fitting to one of the members on the piston side of the cam plate and the piston operation. A synchronization plate having spline teeth that are spline-fitted to the other spline of the member, and a spring that urges the cam plate and the synchronization plate away from each other. An inclined cam surface is formed in the direction, and when the piston is not operated, the synchronization plate is urged toward the piston by the spring and does not engage with the other of the members by spline. The above problem has been solved by a friction engagement device that is spline-fitted with the other of the members.
[0008]
Thirdly, the present invention provides a snap ring provided on the outer side in the axial direction of the retaining plate, a spring for biasing the retaining plate toward the plate group, and between the piston and the plate group. And a synchronous plate having spline teeth that are spline-fitted to one of the members and spline-fitted to the other spline of the member when the piston is operated, and the one spline of the member is notched and the plate An inclined cam surface is formed in a circumferential direction on a surface facing the group, and the retaining plate has a cam surface facing the cam surface and is held in a notch portion of the spline. During operation, the synchronization plate is urged toward the piston by the spring and does not spline fit with the other of the members. The retaining plate when down operation has solved the above problems by frictional engagement devices the synchronization plate moves along one of the spline of the member is the other spline fitting of the member.
[0009]
Note that the piston and the synchronization plate can be integrated.
[0010]
[Action]
First, the operation of the first invention will be described. When the piston is not operated, the plates are separated from each other, and no torque is transmitted between the members.
When the oil pressure is applied to the oil chamber, the piston is activated and the plate group starts frictional engagement. At the same time, the retaining plate and the cam plate come into contact with each other on the cam surfaces. Since the rotation of the cam plate is not restricted with respect to both members, the cam plate is dragged by the plate group and tries to rotate in the same direction. At this time, an axial force by the piston and a circumferential force caused by being dragged by the plate group act on the cam plate. Since the inclination angle of the cam surface is set to a predetermined angle, the plate group is gradually synchronized.
When the relative rotational speed of the plate group becomes 0, the cam surfaces slip. As a result, the retaining plate and the cam plate are completely brought into close contact with each other, and the synchronizing plate is moved in the axial direction, so that the synchronizing plate is splined with the other spline of the member.
This operation is caused by a decrease in rotational inertia on the other side of the member or a decrease in transmission torque between the plates.
As a result, the relatively rotating members are completely synchronized by spline fitting, not by frictional force.
[0011]
In the second invention, the operation of the cam surface occurs between the cam plate and the synchronization plate. In the third invention, the operation of the cam surface occurs between the end surface of the spline and the retaining plate. However, the operation in which both members are completely synchronized by the spline fitting is the same as in the first invention.
[0012]
【Example】
Embodiments of the friction engagement device according to the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment, and FIGS. 3 and 4 show a second embodiment. 5 and 6 show a third embodiment. In the following embodiments, the relatively rotating members are the hub and the drum, but the relatively rotating members may be the drum and the housing. The friction engagement device in the latter case corresponds to a brake.
[0013]
A first embodiment of a friction engagement device according to the present invention will be described with reference to FIGS. The friction engagement device 10 includes a drum 20 having a spline 22 formed on the inner periphery and a hub 30 having a spline 32 formed on the outer periphery. A mating plate 24 is spline fitted to the spline 22 of the drum 20, and a clutch plate 36 to which a friction material 34 is fixed is fitted to the spline 32 of the hub 30. These plate groups 24 and 36 are arranged alternately.
[0014]
The retaining plate 40 is spline-fitted to the drum 20 on one side in the axial direction of the plate groups 24 and 36. The retaining plate 40 is prevented from moving in one axial direction by a snap ring 44. A piston 50 is fitted to the drum 20 on the other side in the axial direction of the plate groups 24 and 36. The piston 50 is operated in the axial direction by the hydraulic pressure acting on the oil chamber 52. The return of the piston 50 is made by a coil spring 54.
[0015]
Between the retaining plate 40 and the plate groups 24 and 36, a cam plate 60 that is not restricted in rotation with respect to the drum 20 and the hub 30 is disposed. The cam plate 60 protrudes toward the retaining plate 40 on the inner peripheral side. A cam surface 64 is formed on the protruding portion 62. Similarly, a cam surface 42 is formed on the retaining plate 40 on the side facing the cam plate 60. As shown in FIG. 2, the cam surfaces 42 and 64 are formed such that the axial thickness increases or decreases in the circumferential direction when viewed from the radial direction.
The cam plate 60 has a diameter slightly smaller than the diameter of the circle formed by the tip of the spline 22 of the drum 20. Further, the cam surface 64 of the cam plate 60 is in partial contact with the cam surface 42 of the retaining plate 40 when the piston is not operated. Therefore, the cam plate 60 is not completely restrained with respect to the drum 20 but rotates in the same direction as the mating plate 24 and the retaining plate 40.
A wave spring 66 has a role of pushing the plate groups 24 and 36 back toward the piston 50 when the piston 50 is in an inoperative state.
[0016]
A synchronization plate 70 is disposed between the piston 50 and the plate groups 24 and 36. The synchronization plate 70 is fitted to the spline 22 of the drum 20. A spline 72 that can be spline-fitted to the spline 32 of the hub 30 is formed on the inner peripheral side. The hub 30 has such a length that the synchronization plate 70 is not spline fitted to the hub 30 when the piston is not operated.
In this embodiment, the piston 50 and the synchronization plate 70 are separate bodies, but they may be integrated.
[0017]
Next, the operation will be described. When the piston 50 is not in operation, the plate groups 24 and 36 are spaced from each other, and the drum 20 and the hub 30 can rotate relative to each other. At this time, torque is not transmitted. The cam plate 60 abuts on the retaining plate 40 at the cam surface 64 and rotates in the same direction as the drum 20.
[0018]
When oil is supplied to the oil chamber 52, the gap between the plate groups 24 and 36 disappears, and the retaining plate 40 and the cam plate 60 start to engage at the cam surfaces 42 and 64. An axial force by the piston 50 and a circumferential force by frictional engagement with the clutch plate 36 act on the cam plate 60. The axial force is a force that tries to bring the retaining plate 40 and the cam plate 60 into close contact with each other, and the circumferential force is a force that tries to separate the retaining plate 40 and the cam plate 60 from each other. By forming the cam surfaces 42 and 64 at a predetermined inclination angle, the plate groups 24 and 36 continue to be in frictional engagement, so the drum 20 and the hub 30 try to synchronize.
[0019]
When the relative rotational speed of the plate group becomes 0 and there is no force to separate the retaining plate 40 and the cam plate 60, the retaining plate 40 and the cam plate 60 are brought into close contact with each other at the cam surfaces 42 and 64. The synchronization plate 70 moves in the axial direction and is spline fitted to the spline 32 of the hub 30. In this way, the drum 20 and the hub 30 can rotate together. Since the drum 20 and the hub 30 rotate integrally after the synchronization plate 70 is spline-fitted with the spline 32 of the hub 30, it is sufficient to apply a hydraulic pressure against the urging force of the spring 66 to the oil chamber 52. . Therefore, high hydraulic pressure is not required. High hydraulic pressure can be released by providing a solenoid valve or the like in the hydraulic circuit.
[0020]
3 and 4 show a second embodiment of the frictional engagement device according to the present invention. In the friction engagement device 110 according to the present embodiment, the cam plate 160 is provided on the piston 150 side of the plate groups 124 and 136. Further, the synchronization plate 170 is provided integrally with the piston 150.
[0021]
The cam plate 160 is not restricted in rotation by the drum 120 and the hub 130, and is disposed with a slight gap from the tip of the spline 122 of the drum 120. The cam plate 160 has a plurality of comb-like protrusions 162 extending radially on the inner peripheral side. An inclined cam surface 164 is formed in the circumferential direction at the tip of each protrusion 162.
The synchronization plate 170 integral with the piston 150 has a protrusion 174 that complements the protrusion 162. At its tip, it has a cam surface 176 that complements the cam surface 164 of the cam plate 160. A wave spring 166 is disposed between the cam plate 160 and the piston 150 to urge them apart.
[0022]
When the piston is not operated, the plate groups 124 and 136 have a gap therebetween, and no torque is transmitted between the drum 120 and the hub 130. When oil begins to be supplied to the oil chamber 152, the gap between the plate groups 124 and 136 decreases, and the cam surfaces 164 and 176 engage with each other. The plate groups 124 and 136 are frictionally engaged to synchronize the drum 120 and the hub 130. When the relative rotational speed of the plate groups 124 and 136 becomes zero, slip occurs on the cam surfaces 164 and 176. The protrusions 162 and 174 are fitted to each other, and the piston 150 is operated in the axial direction. Since the protrusion 174 of the piston 150 is formed to have the same width as the spline 132 of the hub 130, the piston 150 completely connects the drum 120 and the hub 130 when slippage occurs on the cam surfaces 164 and 176.
[0023]
5 and 6 show a third embodiment of the friction engagement device according to the present invention. In the frictional engagement device 210 of this embodiment, the drum 220 has a snap ring 244 on the opposite side to the piston 250. A spring 266 is disposed between the retaining plate 240 and the snap ring 244, and this spring 266 biases the retaining plate 240 toward the plate groups 224 and 236.
[0024]
The spline 222 of the drum 220 is notched in the circumferential direction at a portion where the retaining plate 240 is fitted. An inclined cam surface 264 is formed in the circumferential direction on the end surface of the spline 222 facing the plate groups 224 and 236. Similarly, a cam surface 242 is formed on the retaining plate 240. When the retaining plate 240 is located at the notched portion, the retaining plate 240 is allowed to rotate slightly in the circumferential direction and is movable in the direction in which the spline 222 extends.
[0025]
A synchronization plate 270 integrated with the piston 250 is disposed on the piston side of the plate groups 224 and 236. The synchronization plate 270 is fitted to the spline 222 of the drum 220. In addition, a spline 272 is formed on the inner periphery of the synchronization plate 270 so as to be splined to the spline 232 of the hub 230 when the piston 250 is operated in the axial direction. When the relative rotational speed of the plate groups 224 and 236 becomes zero, the retaining plate 240 moves along the spline 222 of the drum 220, and the synchronization plate 270 integrated with the piston 250 is fitted to the spline 232 of the hub 230.
[0026]
As described above, according to the present invention, the cam surface acts to gradually reduce the rotational difference between the two members, and mechanically synchronize the drum and the hub when the relative rotational speed of the plate group becomes zero. Have
[0027]
【The invention's effect】
In the first to third aspects of the invention, when the hydraulic pressure starts to act on the piston, the action of the cam surfaces causes the plate group to frictionally engage so as to synchronize the members, and when the relative rotational speed of the plate group becomes zero, The synchronization plate can move axially and the members can be mechanically synchronized by the spline. Accordingly, it is possible to increase the transmission capacity between the members by suppressing the increase in the size of the plate group and the piston and the like and the power loss of the peripheral devices such as the hydraulic pump.
[0028]
In the invention of claim 4, since the synchronization plate is integrated with the piston, and the operation of the synchronization plate is interlocked with the operation of the piston, the switching between the torque transmission state and the torque non-transmission state is reliable, and the number of parts is also reduced. can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of a friction engagement device according to the present invention.
2 is an arrow view of the friction engagement device of FIG. 1 as viewed from A. FIG.
FIG. 3 is a cross-sectional view of a second embodiment of a friction engagement device according to the present invention.
4 is an arrow view of the friction engagement device of FIG.
FIG. 5 is a cross-sectional view of a third embodiment of a friction engagement device according to the present invention.
6 is an arrow view of the spline of the drum of the friction engagement device in FIG. 5 as viewed from C. FIG.
FIG. 7 is a cross-sectional view of a conventional friction engagement device.
[Explanation of symbols]
10, 110, 210 Friction engagement device 20, 120, 220 Drum 22, 122, 222 Spline 24, 124, 224 Mating plate (plate group)
30, 130, 230 Hub 32, 132, 232 Spline 36, 136, 236 Clutch plate (plate group)
40, 240 Retaining plate 42, 242 Cam surface 50, 150, 250 Piston 60, 160 Cam plate 64, 164, 264 Cam surface 66, 166, 266 Spring 70, 170, 270 Synchronization plate 72, 272 Spline 176 Cam surface

Claims (4)

Two members that rotate relative to each other and form a cylindrical space therebetween, a plate group that is spline-fitted to each of the members in the cylindrical space, and the member on one axial side of the plate group A hydraulically operated piston that is disposed on one of the members on the other side in the axial direction of the plate group and frictionally engages the plate group with the retaining plate on the other side in the axial direction of the plate group In the friction engagement device comprising:
Between the retaining plate and the plate group, a cam plate whose rotation is not constrained with respect to the member, a spring for separating and biasing the retaining plate and the cam plate, and between the piston and the plate group And a synchronization plate having spline teeth that are spline fitted to one of the members and spline fitted to the other spline of the member when the piston is operated,
The retaining plate and the cam plate are opposed to each other with a cam surface formed so that the axial thickness increases or decreases in the circumferential direction,
The synchronization plate is biased toward the piston by the spring when the piston is not operated, and does not spline fit with the other of the members, and the synchronization plate is splined with the other of the members when the piston is operated. Features
Friction engagement device. Two members that rotate relative to each other and form a cylindrical space therebetween, a plate group that is spline-fitted to each of the members in the cylindrical space, and the member on one axial side of the plate group A hydraulically operated piston that is disposed on one of the members on the other side in the axial direction of the plate group and frictionally engages the plate group with the retaining plate on the other side in the axial direction of the plate group In the friction engagement device comprising:
A cam plate whose rotation is not restrained with respect to the member on the piston side of the plate group, and a spline fit to one of the members on the piston side of the cam plate and to the other spline of the member when the piston is operated A synchronization plate having spline teeth for spline fitting, and a spring for separating and energizing the cam plate and the synchronization plate;
An inclined cam surface is formed in a circumferential direction on the opposing surface of the cam plate and the synchronization plate,
The synchronization plate is biased toward the piston by the spring when the piston is not operated, and does not spline fit with the other of the members, and the synchronization plate is splined with the other of the members when the piston is operated. Features
Friction engagement device. Two members that rotate relative to each other and form a cylindrical space between the two members, a plate group that is spline-fitted to each of the members in the cylindrical space, and one of the members in the axial direction of the plate group. A retaining plate disposed on one side and a hydraulically operated piston disposed on one of the members on the other axial side of the plate group and frictionally engaging the plate group with the retaining plate; In the friction engagement device comprising:
A snap ring provided on the axially outer side of the retaining plate, a spring for urging the retaining plate toward the plate group, and a spline fit on one of the members between the piston and the plate group And a synchronizing plate having spline teeth that are spline fitted to the other spline of the member when the piston is operated,
One spline of the member is cut away to form an inclined cam surface in a circumferential direction on a surface facing the plate group, and the retaining plate has a cam surface facing the cam surface, and the spline The synchronizing plate is urged toward the piston by the spring when the piston is not operated and does not spline fit with the other of the members, and the retaining plate is It moves along one spline of the member, and the synchronization plate is spline fitted with the other of the member,
Friction engagement device. The friction engagement device according to claim 1, wherein the piston and the synchronization plate are integrated.

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