JP2008164063A - Hydraulic clutch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve responsiveness of movement of a piston by minimizing resistance to the axial movement of the piston. <P>SOLUTION: This hydraulic clutch device comprises: the piston 2 axially moved by control oil pressure applied to an oil pressure chamber A, to press a clutch 5; a centrifugal hydraulic canceller 3 disposed on the opposite side to the oil pressure chamber A in the piston 2 so that an outer peripheral end 3d radially faces the inner peripheral surface of an outer peripheral cylinder part 2e of the piston 2; and a return spring 4 interposed between the piston 2 and the centrifugal hydraulic canceller 3. The outer peripheral end 3d of the centrifugal hydraulic canceller 3 is provided with a seal lip 32 brought into close contact with an end plate part 2d of the piston 2 when the piston 2 moves in a direction to press the clutch 5 while being not in contact with the end plate part 2d of the piston 2 when the piston 2 moves in a direction to release pressing of the clutch 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydraulic clutch device in an automatic transmission of an automobile.

  The hydraulic clutch device in the automatic transmission of an automobile connects or disconnects the drive plate on the drive shaft side and the driven plate on the driven shaft side by moving the piston in the clutch cylinder by applying or releasing the control oil pressure to the hydraulic chamber. It is supposed to let you. FIG. 4 is a half sectional view showing a conventional hydraulic clutch device cut along a plane passing through an axis O. As shown in FIG.

  In FIG. 4, reference numeral 101 is a housing attached to a drive shaft (not shown), and reference numeral 102 is disposed in the housing 101 so as to be axially movable and between the inner end of the housing 101 and the hydraulic chamber A. The reference numeral 103 is a centrifugal hydraulic pressure that defines an equilibrium oil chamber B in a space opposite to the hydraulic chamber A of the piston 102 with the inner periphery locked to the inner periphery of the housing 101. A canceller, reference numeral 104 is a return spring appropriately inserted between the piston 102 and the centrifugal hydraulic canceller 103, and a reference numeral 105 is a multi-plate clutch.

  The piston 102 is sealed between the inner peripheral portion 101a and the outer peripheral portion 101b of the housing 101 by a seal lip 102a and an O-ring 101c, and the centrifugal hydraulic canceller 103 has an outer peripheral cylindrical portion of the piston 102 at its outer peripheral edge. A seal lip 103a that is slidably in close contact with the inner peripheral surface is integrally bonded. Further, an oil passage C for introducing control oil pressure into the hydraulic chamber A and an oil passage D for supplying hydraulic oil to the equilibrium oil chamber B are opened in the inner peripheral portion 101 a of the housing 101.

  The multi-plate clutch 105 is connected to a plurality of drive plates 105a, which are axially movable on the outer peripheral portion 101b of the housing 101, and a clutch hub 106 provided on a driven shaft (not shown). It has a structure in which a plurality of driven plates 105b that are locked in the circumferential direction so as to be movable in the direction are alternately arranged in the axial direction. Further, a pressing flange portion 102b formed at the end of the outer peripheral cylindrical portion of the piston 102 is opposed to the multi-plate clutch 105 in the axial direction.

  That is, in this hydraulic clutch device, by applying a control hydraulic pressure to the hydraulic chamber A through the oil passage C, the piston 102 is displaced in a direction in which the return spring 104 is compressed, and the drive plate 105a in the multi-plate clutch 105 is driven. The plate 105b is pressed and frictionally engaged. For this reason, the multi-plate clutch 105 is brought into a connected state, and the drive torque of the drive shaft (not shown) is transmitted from the housing 101 to the driven shaft (not shown) via the multi-plate clutch 105 and the clutch hub 106.

  In addition, when the control oil pressure of the hydraulic chamber A is released from this connected state, the piston 102 returns to the direction of reducing the volume of the hydraulic chamber A by the restoring force of the compressed return spring 104, and the multi-plate clutch The frictional engagement state between the drive plate 105a and the driven plate 105b at 105 is released, thereby interrupting the driving force transmission from the drive shaft to the driven shaft.

In the above-described clutch engagement / disengagement operation, the housing 101 and the piston 102 rotate around the axis O together with the drive shaft, so that the hydraulic oil introduced into the hydraulic chamber A is pressed to the outer peripheral side by centrifugal force. Accordingly, a centrifugal hydraulic pressure is generated in the hydraulic chamber A, and this centrifugal hydraulic pressure acts to prevent the return operation of the piston 102 by the return spring 104. However, since the hydraulic pressure is also generated in the hydraulic oil filled in the equilibrium oil chamber B between the piston 102 and the centrifugal hydraulic canceller 103, the centrifugal hydraulic pressure is substantially balanced on both axial sides of the piston 102, The clutch can be smoothly disconnected by the return operation of the piston 102 (see, for example, Patent Document 1).
JP 2001-241467 A

  However, in this type of hydraulic clutch device, the sealing lip 102a provided on the piston 102 is pressed against the inner peripheral surface of the outer peripheral portion 101b of the housing 101 by the control hydraulic pressure and the centrifugal hydraulic pressure of the hydraulic chamber A, and the centrifugal hydraulic pressure is increased. Similarly, since the seal lip 103a provided in the canceller 103 is pressed against the inner peripheral surface of the outer peripheral cylindrical portion of the piston 102 by the centrifugal oil pressure of the equilibrium oil chamber B, the responsiveness of the clutch intermittent operation is improved by the axial frictional resistance. The problem that it is difficult to improve is pointed out.

  The present invention has been made in view of the above points, and a technical problem thereof is to improve the responsiveness of the operation of the piston in the hydraulic clutch device.

  As means for effectively solving the above-described technical problem, a hydraulic clutch device according to the present invention includes a piston that moves in an axial direction by a control hydraulic pressure applied to a hydraulic chamber to press the clutch, and the piston in the piston. A centrifugal hydraulic canceller disposed on the opposite side of the hydraulic chamber and having an outer peripheral end radially opposed to an inner peripheral surface of an outer peripheral cylindrical portion formed on the piston, and interposed between the piston and the centrifugal hydraulic canceller A return spring, and a direction in which the piston is released from pressing the clutch when the piston moves to the outer peripheral end of the centrifugal hydraulic canceller in a direction in which the piston presses the clutch. A seal lip is provided which is in non-contact with the end plate portion of the piston when moved to.

  According to the above configuration, the seal lip provided on the outer peripheral portion of the centrifugal hydraulic canceller does not slide in the axial direction with respect to the inner peripheral surface of the outer peripheral cylindrical portion of the piston. In addition, wear is also suppressed. In addition, when the piston moves in the direction to release the clutch, the seal lip provided on the outer peripheral portion of the centrifugal hydraulic canceller is in non-contact with the end plate portion of the piston, and this also reduces wear. In addition, the crushing margin of the seal lip when in close contact with the end plate portion of the piston is small, so that permanent deformation is suppressed and durability is improved.

  According to the hydraulic clutch device of the present invention, since the seal lip provided on the outer peripheral portion of the centrifugal hydraulic canceller does not generate axial frictional resistance, the response of the piston operation can be improved accordingly. Moreover, the durability of the seal lip can be improved.

  Hereinafter, a preferred embodiment of a hydraulic clutch device according to the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view in a clutch disengaged state, showing the first embodiment cut along a plane passing through the axis O, and FIG. 2 is a half sectional view in the clutch engaged state.

  In the hydraulic clutch device shown in FIGS. 1 and 2, reference numeral 1 is a housing having an annular working space S centered on an axis O, and reference numeral 2 is disposed in the working space S so as to be movable in the axial direction. An annular piston that defines a hydraulic chamber A between the housing 1 and the reference numeral 3 is disposed on the opposite side of the piston 2 from the hydraulic chamber A, and the inner periphery of the housing 1 via the retaining ring 31 A centrifugal hydraulic canceller that is axially supported by the inner peripheral portion 1a and defines an equilibrium oil chamber B between the piston 2 and reference numeral 4 is interposed between the piston 2 and the centrifugal hydraulic canceller 3 in an appropriately compressed state. The mounted return spring, reference numeral 5 is a multi-plate clutch.

  The housing 1 is attached to a drive shaft (not shown), and an annular groove for mounting a retaining ring 31 for locking the centrifugal hydraulic canceller 3 is formed on the inner peripheral portion 1a thereof, and the housing 1 operates in the hydraulic chamber A. An oil passage 12 for introducing a control oil pressure by oil (ATF) and an oil passage 13 for supplying hydraulic oil to the equilibrium oil chamber B are opened. An O-ring 14 is attached to an annular groove formed on the outer peripheral surface of the inner peripheral portion 1 a of the housing 1 so as to pass between the oil passages 12 and 13.

  The piston 2 is manufactured by stamping press molding of a metal plate or the like, and is loosely fitted on the outer peripheral surface of the inner peripheral portion 1a of the housing 1 and is in close contact with the O-ring 14 so as to be slidable in the axial direction. A peripheral cylinder portion 2a, a spring receiving portion 2b that extends in the radial direction from the end portion on the hydraulic chamber A side, and carries one end of the return spring 4, and an intermediate cylinder that extends concentrically from the outer peripheral end to the inner peripheral cylinder portion 2a. Part 2c, end plate part 2d extending in the radial direction from the end on the hydraulic chamber A side, outer peripheral cylindrical part 2e extending concentrically with the inner peripheral cylindrical part 2a from the outer peripheral end thereof, and further, the outer peripheral cylindrical part 2e It has a pressing flange 2f formed at the end on the multi-plate clutch 5 side. A seal lip 21 made of a rubber-like elastic material is integrally bonded to a bent portion between the end plate portion 2d and the outer peripheral cylindrical portion 2e, and is slidable in the axial direction on the inner peripheral surface of the outer peripheral portion 1b of the housing 1. Have been close to. In addition, a plurality of protrusions 2g that are driven out toward the hydraulic chamber A are formed at the end plate portion 2d at equal intervals in the circumferential direction.

  The centrifugal hydraulic canceller 3 is manufactured by stamping press molding of a metal plate or the like. The centrifugal hydraulic canceller 3 is supported in the axial direction on the inner peripheral portion 1a of the housing 1 via the retaining ring 31 described above and the return spring 4 A disc-shaped spring receiving portion 3a that supports the other end of the piston, an intermediate cylindrical portion 3b that extends from the outer peripheral end to the piston 2 side, and an outer peripheral end portion that extends in the radial direction from the end portion. 2e has an end plate portion 3c opposed to the inner peripheral surface in the radial direction. A seal lip 32 made of a rubber-like elastic material is integrally bonded to the outer peripheral end 3d of the end board 3c.

  The multi-plate clutch 5 is connected to a plurality of drive plates 51 that are circumferentially engaged with the outer peripheral portion 1b of the housing 1 and a clutch hub 6 provided on a driven shaft (not shown). It has a structure in which a plurality of driven plates 52 that are locked in the circumferential direction so as to be movable in the direction are alternately arranged in the axial direction. The multi-plate clutch 5 performs a clutch connecting operation or a disconnecting operation by being pressed by the pressing flange portion 2f of the piston 2 or by releasing the pressing.

  The seal lip 32 provided on the centrifugal hydraulic canceller 3 is inclined toward the inner peripheral side from the surface on the equilibrium oil chamber B side at the outer peripheral end 3d of the centrifugal hydraulic canceller 3 toward the end plate 2d side of the piston 2. A base portion 32a that extends in a conical cylinder shape and is bonded to the outer peripheral end portion 3d is closely opposed to the inner peripheral surface of the outer peripheral cylindrical portion 2e of the piston 2 in the radial direction through a slight gap. As shown in FIG. 2, when the piston 2 is in the bottom dead center position where the piston 2 presses the multi-plate clutch 5 by the pressing flange portion 2f to bring it into the connected state, as shown in FIG. In a state where the piston 2 is in a top dead center position, which is in close contact with the inner surface of the portion 2d, that is, as shown in FIG. 1, until the protrusion 2g formed on the end plate portion 2d contacts the upper bottom surface 1c of the housing 1. When the piston 2 is displaced, the piston 2 is not in contact with the piston 2 and is in close proximity to the inner surface of the end plate portion 2d with a slight gap therebetween.

  In the hydraulic clutch device having the above-described configuration, the piston 2 compresses the return spring 4 when the hydraulic chamber A is pressurized by the pressurized supply of hydraulic oil (application of control hydraulic pressure) to the hydraulic chamber A. 1 is displaced from the top dead center position shown in FIG. 2 to the bottom dead center position shown in FIG. 2, the pressing flange 2 f of the piston 2 presses the multi-plate clutch 5, and the drive plate 51 and the driven plate 52 rub against each other. Engage. For this reason, the driving force from a drive shaft (not shown) is transmitted through the housing 1, the drive plate 51 engaged with the housing 1, the driven plate 52, and the clutch hub 6 engaged with the driven plate 52. It is transmitted to a driven shaft (not shown).

  Here, when the piston 2 is at the top dead center position shown in FIG. 1, the seal lip 32 provided in the centrifugal hydraulic canceller 3 is not in contact with the piston 2, that is, seals the outer periphery of the equilibrium oil chamber B. Therefore, the centrifugal hydraulic pressure generated in the equilibrium oil chamber B is released through a slight gap between the base portion 32a of the seal lip 32 and the outer peripheral cylindrical portion 2e of the piston 2, and is depressurized. However, since the pressure in the hydraulic chamber A is also only the centrifugal hydraulic pressure due to a small amount of hydraulic oil remaining in the hydraulic chamber A, the piston toward the balanced oil chamber B due to the differential pressure between the hydraulic chamber A and the balanced oil chamber B The moving force of 2 can be kept small.

  When the piston 2 starts moving from the top dead center position shown in FIG. 1 in the clutch engagement direction, the seal lip 32 provided in the centrifugal hydraulic canceller 3 is not in contact with the piston 2 as described above. In addition, since the centrifugal hydraulic pressure generated in the equilibrium oil chamber B is in an open state, the response of the piston 2 when the control hydraulic pressure is applied to the hydraulic chamber A is good. In addition, even when the end plate portion 2d of the piston 2 is in close contact with the seal lip 32 in the process of moving the piston 2 in the clutch connection direction, the seal lip 32 does not slide with the outer peripheral cylindrical portion 2e of the piston 2. Therefore, the frictional resistance against the axial movement of the piston 2 is generated only in the sliding portion of the seal lip 21 of the piston 2 and the sliding portion of the O-ring 14 and is generated in the seal lip 32 provided in the centrifugal hydraulic canceller 3. do not do. For this reason, the piston 2 can smoothly move in the housing 1 and the multi-plate clutch 5 can be connected.

  Further, since the seal lip 32 of the centrifugal hydraulic canceller 3 extends from the outer peripheral end portion 3d of the end plate portion 3c that is close to and radially opposed to the outer peripheral cylindrical portion 2e of the piston 2, in the clutch engaged state shown in FIG. Even if the centrifugal hydraulic pressure of the equilibrium oil chamber B is significantly increased due to the increase of the rotational speed, the seal lip 32 is backed up by the outer peripheral cylindrical portion 2e of the piston 2 from the outer peripheral side thereof, and is connected to the end plate portion 2d of the piston 2. Maintain a good seal with close contact. For this reason, since the centrifugal hydraulic pressure in the hydraulic chamber A is offset by the centrifugal hydraulic pressure in the equilibrium oil chamber B, the excessive pressure of the hydraulic chamber A does not act on the piston 2, and the hydraulic chamber A substantially does not act. The connection of the multi-plate clutch 5 is maintained only by the applied control oil pressure.

  Next, when the control hydraulic pressure of the hydraulic chamber A is released from the clutch connected state shown in FIG. 2, the piston 2 is moved from the bottom dead center position shown in FIG. Since it is displaced to the top dead center position shown, the friction engagement between the drive plate 51 and the driven plate 52 of the multi-plate clutch 5 is released, and the transmission of the driving force from the drive shaft to the driven shaft is interrupted.

  In the process of moving the piston 2 from the bottom dead center position shown in FIG. 2 in the clutch disengagement direction, the inner surface of the end plate portion 2d of the piston 2 is in close contact with the seal lip 32, that is, the outer periphery of the equilibrium oil chamber B. Is sealed, the centrifugal hydraulic pressure in the hydraulic chamber A is offset by the centrifugal hydraulic pressure in the balanced oil chamber B, and the return movement of the piston 2 (clutch disconnection operation) by the return spring 4 is performed smoothly.

  Further, as described above, the seal lip 32 provided in the centrifugal hydraulic canceller 3 does not slide in the axial direction with the inner peripheral surface of the outer peripheral cylindrical portion 2e of the piston 2, and the piston 2 releases the pressure of the clutch. When near the top dead center, the seal lip 32 is not in contact with the end plate portion 2d of the piston 2, and this also reduces wear. In addition, when the piston 2 is in the vicinity of the top dead center, the crushing margin of the seal lip 32 when the piston 2 is at the bottom dead center is small by making it non-contact with the end plate portion 2d of the piston 2. Become. Accordingly, since the permanent deformation is also suppressed in addition to the suppression of wear, the durability of the seal lip 32 is improved.

  In the process in which the piston 2 moves from the top dead center position shown in FIG. 1 to the bottom dead center position shown in FIG. 2, the seal lip provided on the centrifugal hydraulic canceller 3 has the end plate portion 2 d of the piston 2. Since the seal lip 32 is bent and deformed in the axial direction along with the displacement of the piston 2 after being in close contact with the piston 32, a repulsive force against the bending deformation is generated in the seal lip 32, and this is a resistance against the movement of the piston 2. Become. However, there is no problem if the load of the return spring 4 is adjusted so that the sum of the load of the return spring 4 and the repulsive load of the seal lip 32 is substantially equal to the return spring load of the conventional structure.

  FIG. 3 is a half sectional view of a clutch disengaged state in which a second embodiment of the hydraulic clutch device according to the present invention is cut along a plane passing through the axis O, and this embodiment is a seal lip as described above. The repulsive load due to the bending deformation of 32 is made as small as possible.

  That is, in the hydraulic clutch device shown in FIG. 3, the seal lip 32 provided in the centrifugal hydraulic canceller 3 has an inner peripheral surface from the surface on the outer peripheral end of the end plate portion 3 c of the centrifugal hydraulic canceller 3 on the side of the balanced oil chamber B. The piston 2 extends in a thin conical cylinder shape toward the end plate portion 2d side of the piston 2 while being inclined toward the side, and its tip portion is formed in a curled shape so as to be away from the end plate portion 2d of the piston 2. The seal lip 32 is in close contact with the inner surface of the end plate 2d of the piston 2 when the piston 2 is in the bottom dead center position that presses the multi-plate clutch 5 with the pressing flange 2f. In a state where the piston 2 is at the top dead center position, that is, as shown in FIG. 1, in a state where the piston 2 is displaced to a position where the protrusion 2 g formed on the end plate portion 2 d contacts the upper bottom surface 1 c of the housing 1, As shown in FIG. 3, the curled portion 32 b near the tip is in a state of facing and facing the inner surface of the end plate portion 2 d of the piston 2 through a slight gap.

  Other configurations are the same as those of the first embodiment described above.

  That is, according to the second embodiment, in addition to the same effect as the first embodiment, the rebound load due to the bending deformation can be reduced by making the seal lip 32 thin. Moreover, in the process in which the piston 2 is returned and moved by the return spring 4, the curled portion 32b of the seal lip 32 maintains its close contact with the inner surface of the end plate portion 2d of the piston 2 while changing its curvature, and the balanced oil chamber B Therefore, the present invention can be effectively applied when the stroke distance of the piston 2 is large.

1 is a half sectional view of a clutch disengaged state in which a first embodiment of a hydraulic clutch device according to the present invention is cut along a plane passing through an axis O. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a half sectional view of a clutch connection state showing a first embodiment of a hydraulic clutch device according to the present invention by cutting along a plane passing through an axis O; FIG. 5 is a half sectional view of a clutch disengaged state in which a second embodiment of the hydraulic clutch device according to the present invention is shown cut along a plane passing through an axis O; FIG. 5 is a half cross-sectional view showing a hydraulic clutch device according to the prior art cut along a plane passing through an axis O.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Piston 2d End board part 2e Outer peripheral cylinder part 21 Seal lip 3 Centrifugal hydraulic canceller 31 Stop ring 32 Seal lip 4 Return spring 5 Multi-plate clutch A Hydraulic chamber B Balance oil chamber

Claims (1)

A piston (2) that moves in the axial direction by a control oil pressure applied to the hydraulic chamber (A) and presses the clutch (5);
The piston (2) is disposed on the opposite side of the hydraulic chamber (A), and the outer peripheral end is a centrifugally opposed to the inner peripheral surface of the outer peripheral cylindrical portion (2e) formed on the piston (2). Hydraulic canceller (3),
A return spring (4) interposed between the piston (2) and the centrifugal hydraulic canceller (3);
The piston (2) is brought into close contact with the end plate (2d) of the piston (2) when the piston (2) moves in the direction of pressing the clutch (5) to the outer peripheral end of the centrifugal hydraulic canceller (3). A seal lip (32) is provided that is not in contact with the end plate (2d) of the piston (2) when (2) moves in a direction to release the pressure of the clutch (5). Hydraulic clutch device.

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