JP2005282654A - Clutch shock torque prevention valve device and release cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability by restricting the amount of bending deformation of a check valve, thereby preventing an increase in maintenance cost.
Shock torque prevention is provided in a passage 14 through which hydraulic fluid passes in both directions between a master cylinder 11 and a release cylinder 12 and restricts the flow rate of hydraulic fluid in the recirculation direction to return from the cylinder 12 to the cylinder 11. The valve device 20 for use. A valve body 59 having an inner hole 50 that constitutes a part of the passage 14, a large-diameter throttle hole 53a that is provided in the inner hole 50 and allows hydraulic fluid to pass in both directions, and in a direction opposite to the reflux direction. A valve body 55 formed with a valve hole 55a for allowing hydraulic fluid to pass therethrough, and is held by the valve body 55 so as to be able to bend and deform. When the hydraulic fluid passes in the recirculation direction, the valve body 55 is surrounded by the valve hole 55a. A check valve 54 that is pressed by the hydraulic fluid to close the valve hole 55a and a stopper portion 71 that is provided on the valve main body 59 side and regulates the amount of deformation of the check valve 54 are provided.
[Selection] Figure 1

Description

  The present invention relates to a valve device for preventing shock torque of a clutch and a release cylinder incorporating the valve device.

  When shifting a vehicle equipped with a manually operated transmission, first depress the clutch pedal to temporarily disconnect the engine and transmission, then operate the shift lever to switch the gear ratio of the transmission gear, Next, a series of operations of releasing the depression of the clutch pedal and returning the connection between the engine and the transmission is performed.

  In addition, the above-described speed change is performed by a mechanism described below. When the clutch pedal is depressed, the hydraulic fluid is discharged from the master cylinder, flows into the release cylinder, and the engine and transmission are disconnected. Further, when the depression of the clutch pedal is released, the hydraulic fluid returns from the release cylinder to the master cylinder, and the engine and the transmission are connected.

  Among these operations, when the difference in the rotational speed between the engine and the transmission rotation shaft is large, such as when starting, if the release of the clutch pedal is quickly performed, the connection between the engine and the transmission is instantaneously established. The shock torque is generated. This clutch shock torque causes engine stoppage, abnormal wear of the clutch, and the like.

  Therefore, conventionally, in order to prevent the shock torque, as shown in FIG. 7, a shock torque preventing valve device 120 that restricts the flow of hydraulic fluid flowing back from the release cylinder 112 to the master cylinder 111 is provided as a release cylinder 112 and a master. The structure arrange | positioned on the path | route 114 of the hydraulic fluid between the cylinders 111 is proposed (refer patent document 1).

  In the case of this configuration, the valve device 120 restricts the flow of the hydraulic fluid that recirculates from the release cylinder 112 to the master cylinder 111. Therefore, even when the depression of the clutch pedal 110 is quickly released, the connection between the engine and the transmission is performed. Is not performed instantaneously, and shock torque can be prevented.

  The configuration of the valve device 120 having such an operation is as follows. That is, it has a master cylinder side main body 151 provided with a port 152b connected to the master cylinder 111, an inner hole 150, and a mounting hole 170, and a port 152a connected to the release cylinder 112. A release cylinder side main body 159 that constitutes a valve device main body together with the cylinder side main body 151, and is attached to the inner hole 150 in a state of being sandwiched between the main bodies 151 and 159, and includes a large diameter throttle hole 153 a and a check valve 154. The fixed valve body 155, the movable valve body 157 having a small-diameter throttle hole 153b slidably accommodated in the inner hole 150 in a direction to come in contact with and away from the fixed valve body 155, and the inner hole 150 are provided. A spring 158 that presses the movable valve body 157 toward the fixed valve body 155 is provided.

The check valve 154 has an annular shape made of an elastic material such as rubber, and has an inner peripheral side held by a fixed valve body 155 so as to close a valve hole 155a provided separately from the large-diameter throttle hole 153a. Therefore, the pressure of the working fluid flowing from the master cylinder 111 to the release cylinder 112 is bent and deformed to the port 152a side to open the valve hole 155a (see FIG. 8), while the working fluid flows back from the release cylinder 112 to the master cylinder 111. When the check valve 154 returns to its original shape, it closes the valve hole 155a. Accordingly, the operation of the check valve 154 allows the flow of hydraulic fluid from the master cylinder 111 to the release cylinder 112 through the valve hole 155a, while operating from the release cylinder 112 to the master cylinder 111 through the valve hole 155a. The liquid flow is interrupted.
JP 2002-188659 A

  However, if the amount of bending deformation of the check valve 154 is too large, the durability of the check valve deteriorates, the replacement frequency increases, and maintenance costs increase.

  The present invention has been made in view of the above problems, and provides a shock torque preventing valve device capable of regulating the amount of bending deformation of the check valve and improving durability, and a release cylinder incorporating the valve device. The purpose is to provide.

  The invention according to claim 1 is disposed in a passage through which hydraulic fluid is passed in both directions between a master cylinder operated by a clutch pedal and a release cylinder that moves the clutch by hydraulic pressure of the hydraulic fluid. A valve body for shock torque prevention that prevents shock torque of the clutch by restricting the flow rate of the working fluid in the recirculation direction that recirculates to the master cylinder, the valve body having an inner hole that constitutes a part of the passage And a valve body provided in the inner hole and formed with a first hole for passing hydraulic fluid in both directions and a second hole for passing hydraulic fluid in a direction opposite to the reflux direction; The valve body is held at the upstream side in the return direction so that it can be bent and deformed, and when the hydraulic fluid passes in the return direction, the hydraulic fluid is pressed around the second hole of the valve body to close the second hole, A check valve that opens the second hole when hydraulic fluid passes in the direction opposite to the flow direction, and a stopper portion that is provided on the valve body side and restricts the amount of deformation of the check valve are provided. It is characterized by that.

  According to a second aspect of the present invention, in the valve device for preventing shock torque of the clutch according to the first aspect, the stopper portion has an escape passage through which the hydraulic fluid that has passed through the second hole in the direction opposite to the return direction is passed. It is formed.

  According to a third aspect of the present invention, in the valve device for preventing shock torque of the clutch according to the first or second aspect, the second hole is disposed at a constant radius from the axial center of the inner hole, and the reverse The stop valve is formed in an annular shape, and the inner peripheral side of the annular check valve is held by the valve body, and the stopper portion is located at a position where the outer peripheral side comes into contact with the outer peripheral portion of the check valve. It is provided on the valve body side.

  A fourth aspect of the present invention is the valve device for preventing shock torque of the clutch according to any one of the first to third aspects, wherein a plurality of the second holes are provided along a circumferential direction of the annular check valve. It is characterized by.

  A fifth aspect of the present invention is the valve device for preventing shock torque of the clutch according to the fourth aspect, wherein a plurality of the stopper portions are provided along the circumferential direction of the annular check valve so as to be adjacent to each other. An escape passage is provided between the matching stopper portions.

  A sixth aspect of the present invention is a release cylinder incorporating the clutch shock torque preventing valve device according to any one of the first to fifth aspects.

  According to the first aspect of the present invention, the check valve, which is held so as to be able to bend and deform on the upstream side in the return direction of the valve body, is disposed around the second hole of the valve body when the hydraulic fluid passes in the return direction. When the hydraulic fluid passes through the second hole in the direction opposite to the recirculation direction while being pressed by the hydraulic fluid, the check valve is bent and deformed in the reverse direction to open the second hole. To. When the check valve is bent and deformed in the reverse direction, the stopper portion restricts the amount of deformation of the check valve, thereby improving the durability of the check valve and thereby reducing the replacement frequency. it can.

  According to the second aspect of the present invention, even if the stopper portion comes into contact with the check valve to regulate the amount of deformation of the check valve, the relief passage provided in the stopper portion causes the second hole to extend in the direction opposite to the return direction. Since the passed hydraulic fluid is released to the release cylinder side, the supply of the hydraulic fluid to the release cylinder can be performed without any problem.

  According to the invention described in claim 3, the annular check valve is configured such that the outer peripheral side is bent and deformed by the inner peripheral side being held by the valve body, and the stopper provided on the valve main body side. The portion comes into contact with the outer peripheral side of the check valve that bends and deforms, and regulates the amount of deformation of the check valve outer peripheral portion.

  According to the fourth aspect of the present invention, a plurality of second holes provided in the valve body are opened and closed by one check valve.

  According to the fifth aspect of the present invention, the check valve is bent and deformed over its entire circumference by the hydraulic fluid passing through the plurality of second holes provided in the circumferential direction of the check valve in the direction opposite to the reflux direction. Even so, since the stopper portion is provided so as to skip along the circumferential direction of the annular check valve, the stopper portion can restrict the bending deformation over the entire circumference of the check valve. In addition, since the escape passages are also present, the hydraulic fluid that has passed through the second hole in the direction opposite to the reflux direction can be smoothly released to the release cylinder side.

  According to the sixth aspect of the present invention, since the release cylinder has a built-in valve device, it is not necessary to attach the release cylinder and the valve device when installing to the vehicle. Well, workability can be greatly improved.

  Hereinafter, embodiments of the present invention will be described.

  1 and 2 are front sectional views of the shock torque preventing valve device according to this embodiment. FIG. 1 shows a state in which the movable valve body 57 and the fixed valve body 55 are in contact with each other, and FIG. The state which the body 57 and the fixed valve body 55 have left | separated is shown.

  The operation of the clutch pedal 10 is transmitted to the master cylinder 11 connected thereto, and the hydraulic fluid sent out from the master cylinder 11 flows into the release cylinder 12 via the pipe 14 and the shock torque preventing valve device 20. One end of the output rod 12a of the release cylinder 12 is connected to the other end of a release fork 13 connected to a clutch (not shown).

  The shock torque preventing valve device 20 is disposed on the hydraulic fluid passage 14 between the master cylinder 11 and the release cylinder 12, and the release cylinder side main body 51b is inserted into the mounting hole 70 of the master cylinder side main body 51a. A valve device main body 59 having an inner hole 50 having a circular cross section, a fixed valve body 55 fixed in the inner hole 50 in a state sandwiched between both main bodies 51a and 51b, and an inner hole 50 includes a movable valve body 57 slidably housed in a direction in which the fixed valve body 55 is separated from and contacted with the fixed valve body 55, and a spring 58 that presses the movable valve body 57 toward the fixed valve body 55.

  The main body 51a on the master cylinder side is provided with a port 52b connected to the master cylinder 11, and the port 52b and the inner hole 50 communicate with each other. The main body 51b on the release cylinder side is provided with a port 52a connected to the release cylinder 12, and the port 52a and the inner hole 50 communicate with each other. The axial center of the inner hole 50 is in the left-right direction.

  The fixed valve body 55 has a projecting portion 55c having a circular cross section on the port 52a side of the disc portion 55b. A large-diameter throttle hole 53a as a first hole is formed in the axial center portion, and the disc portion 55b. A plurality of (for example, twelve) valve holes 55a as second holes are provided on the same radius. The large-diameter throttle hole 53a allows the working fluid to flow in both directions of the recirculation direction in which the working fluid recirculates from the release cylinder 12 to the master cylinder 11 and the opposite direction.

  In addition, a concave annular groove 55d is formed in the projecting portion 55b, and the annular groove 55d holds the inner peripheral side of the annular check valve 54. In the radial direction portion of the check valve 54, The valve hole 55a is located. The check valve 54 is made of an elastic material such as rubber, and the hydraulic fluid that has passed through the valve hole 55a in the reverse direction is bent and deformed so that the outer peripheral side swings to the port 52a side (right side in FIG. 1). open. Further, the check valve 54 is pressed against the peripheral portion of the valve hole 55a in the fixed valve body 55 by the pressure of the hydraulic fluid in the reflux direction to close the valve hole 55a. Therefore, by the action of the check valve 54, the flow of hydraulic fluid in the reverse direction through the valve hole 55a is allowed, but the flow of hydraulic fluid in the return direction through the valve hole 55a is blocked.

  On the port 52a side (right side in FIG. 1) of the check valve 54, a stopper portion 71 that restricts the amount of deformation of the check valve 54 is provided.

  FIG. 3 is a view of the stopper portion 71 as viewed from the left side of FIG. A plurality of stoppers 71 (four in the illustrated example) are provided in the inner back portion of the inner hole 50 of the main body 51b on the release cylinder side, along the circumferential direction of the check valve 54. Each stopper portion 71 is formed to project toward the shaft center and toward the check valve 54. A slit-shaped escape passage 72 having a deeply recessed axial center is formed between the stopper portions 71 adjacent to each other by a notch or the like. In the illustrated example, four escape passages 72 are formed at equal intervals.

  Therefore, even if the check valve 54 is bent and deformed and is received by the stopper portion 71 and there is no gap between the check valve 54 and the stopper portion 71, the check valve 54 passes through the valve hole 55a in the direction opposite to the reflux direction. The hydraulic fluid escapes to the port 52a via the escape passage 72.

  As shown in FIG. 4, the movable valve body 57 is formed with a wall 57b on one end side (port 52a side) of the tubular portion 57a. The tubular portion 57a has an axial groove 63 at equal intervals. Are provided in four places. The groove 63 is provided so as to open to a stepped portion 62 formed between the distal end portion 60 and the outer periphery of the movable valve body 57 and also to open inside the cylindrical portion 57a. Therefore, the working fluid can flow in both directions through the groove 63. The wall 57b is formed with a small-diameter throttle hole 53b that allows the working fluid to pass through the shaft center in both directions.

  As shown in FIG. 1, the small-diameter throttle hole 53b is provided at a position where the respective central axes coincide with the large-diameter throttle hole 53a. Therefore, the pressing force that urges the movable valve body 57 in the direction away from the fixed valve body 55 due to the differential pressure due to the pressure loss of the hydraulic fluid in the small diameter throttle hole 53b causes the pressure receiving surface (small diameter throttle hole of the movable valve body 57). 53b), the movable valve element 57 can slide smoothly in the inner hole 50.

  Further, a spring 58 is housed inside the cylindrical portion 57a so as to receive the heat of the hydraulic fluid passing through the inner hole 50, and the elastic force of the movable valve body 57 decreases as the temperature decreases. The spring 58 is biased toward the fixed valve body 55 by the elastic force of the spring 58.

  Therefore, the movable valve body 57 that receives the elastic force of the spring 58 contacts the fixed valve body 55 when the elastic force is larger than the pressing force, and the fixed valve body 55 when the elastic force is smaller than the pressing force. Get away from.

  Next, the operation of the shock torque preventing valve device 20 of the present invention and the operation of the check valve will be described.

  First, the operation when the clutch pedal is depressed and the connection between the engine and the transmission is disconnected will be described (see FIG. 1). When the clutch pedal is depressed, the hydraulic fluid is discharged from the master cylinder 11 and flows into the port 52b of the shock torque preventing valve device 20. The hydraulic fluid in the inner hole 50 is supplied to the small-diameter throttle hole 53 b and also to the valve hole 55 a through the groove 63 of the movable valve body 57. The hydraulic fluid supplied to the small-diameter throttle hole 53b flows into the release cylinder 12 from the port 52a via the large-diameter throttle hole 53a. On the other hand, as shown in FIGS. 5A and 5B, the hydraulic fluid supplied to the valve hole 55a bends and deforms the check valve 54 toward the port 52a, that is, upstream in the recirculation direction to open the valve hole 55a. And At this time, when the amount of deformation of the check valve 54 exceeds a predetermined value, the outer peripheral portion comes into contact with the stopper portion 71. Thereby, the bending deformation of the check valve 54 is restricted. Then, the hydraulic fluid that has passed through the valve hole 55 a is supplied to the port 52 a side through the escape passage 72 and flows into the release cylinder 12. In this way, the hydraulic fluid flows into the release cylinder 12, so that the connection between the engine and the transmission is disconnected via the output rod 12 a and the release fork 13. FIG. 5 (b) is an enlarged view of the check valve 54 portion of FIG. 5 (a).

  Next, an operation when the depression of the clutch pedal is released and the engine and the transmission are connected will be described. In this case, the recirculating hydraulic fluid passes through different passages depending on whether the movable valve body 57 is in contact with the fixed valve body 55 or the movable valve body 57 is separated from the fixed valve body 55. The reason why the recirculating hydraulic fluid is configured to pass through different passages is to change the flow of the reflux hydraulic fluid according to the viscosity of the hydraulic fluid, and the details were previously proposed by the applicant of the present application. See the aforementioned Patent Document 1.

  First, the case where the movable valve body 57 is in contact with the fixed valve body 55 will be described. In this case (see FIG. 1), when the depression of the clutch pedal 10 is released, the release fork 13 is pushed leftward in the figure by the unillustrated return spring of the clutch, and the piston of the release cylinder 12 is pushed in the same direction. It is. Further, the piston of the master cylinder 11 is also returned to the initial position by a return spring (not shown). As a result, the hydraulic fluid is discharged from the release cylinder 12 in the recirculation direction, and the recirculated hydraulic fluid flows into the port 52 a of the shock torque prevention valve device 20 and reaches the check valve 54. Then, the check valve 54 is pressed against the peripheral portion of the valve hole 55a in the fixed valve body 55 by the pressure of the recirculating hydraulic fluid to close the valve hole 55a. Therefore, the hydraulic fluid flows out from the port 52a to the port 52b only through a passage made up of the large-diameter throttle hole 53a and the small-diameter throttle hole 53b (that is, receives sufficient throttle), and is returned to the master cylinder 11.

  On the other hand, when the movable valve body 57 is separated from the fixed valve body 55 (see FIG. 2), when the depression of the clutch pedal is released, the release fork 13 is turned to the left in the drawing by the clutch return spring (not shown). The piston of the release cylinder 12 is pushed in the same direction. Further, the piston of the master cylinder 11 is also returned to the initial position by a return spring (not shown). As a result, the hydraulic fluid is discharged from the release cylinder 12 in the recirculation direction, and the recirculated hydraulic fluid flows into the port 52 a of the shock torque prevention valve device 20 and reaches the check valve 54. Then, the check valve 54 is pressed against the peripheral portion of the valve hole 55a in the fixed valve body 55 by the pressure of the recirculating hydraulic fluid to close the valve hole 55a. Since the movable valve body 57 is not in contact with the fixed valve body 55, the hydraulic fluid passes through the step portion 62 and the groove 63 having a sufficient passage area from the port 52a and the large-diameter throttle hole 53a (not so much). It flows out to the port 52b (without being throttled) and is returned to the master cylinder 11.

  As described above, since the check valve 54 blocks the valve hole 55a regardless of whether the movable valve body 57 is in contact with the fixed valve body 55 or away from the fixed valve body 55, the circulating hydraulic fluid has a large diameter. Since only the throttle hole 53a is returned to the master cylinder 11, the shock torque is reliably prevented.

  In the case of this embodiment, as shown in FIG. 5, the stopper portion 71 regulates the amount of deformation of the check valve 54, so that the durability is improved as compared with the check valve 54 that bends indefinitely. As a result, the replacement frequency can be reduced, and the maintenance cost can be prevented from increasing. Even if the stopper portion 71 comes into contact with the check valve 54 so as to restrict the amount of deformation of the check valve 54, the relief passage 72 provided in the stopper portion 71 allows the hydraulic fluid that has passed through the valve hole 55a in the direction opposite to the reflux direction. Since release to the release cylinder 12 side, the supply of hydraulic fluid to the release cylinder 12 can be performed without hindrance. Further, since a plurality of valve holes 55a are provided on the same radius, the plurality of valve holes 55a can be opened and closed by one annular check valve 54. The plurality of valve holes 55a do not have to be provided on the same radius, and may be arranged at positions facing the check valve 54.

  Furthermore, in the case of this embodiment, the check valve 54 extends over its entire circumference by the hydraulic fluid passing through the valve holes 55a provided in the circumferential direction of the check valve 54 in the direction opposite to the reflux direction. Even if it is bent and deformed, since the stopper portion 71 is provided so as to jump along the circumferential direction of the annular check valve 54, the stopper portion 71 can restrict the bending deformation over the entire circumference of the check valve 54. it can. Further, since the escape passage 72 also exists in a flying manner, the hydraulic fluid that has passed through the valve hole 55a in the direction opposite to the recirculation direction can be smoothly released to the release cylinder 12 side.

  In the above-described embodiment, the slit-shaped escape passage is partially formed in the circumferential direction of the stopper portion by a notch or the like, but the present invention is not limited to this. For example, it is good also as a structure which provides a fin-shaped stopper part in the inner hole in multiple places of the circumferential direction of an inner hole, and makes it escape between between stopper parts.

  In the above-described embodiment, the inner peripheral side of the check valve is held and the outer peripheral side is bent and deformed. On the contrary, the present invention holds the outer peripheral side of the check valve and the inner peripheral side is It may be configured to bend and deform.

  In the above-described embodiment, the movable valve body is applied to a configuration in which the movable valve body comes into contact with or separates from the fixed valve body depending on the magnitude relationship between the elastic force and the pressing force, but the present invention is not limited to this. . For example, the present invention can be applied to a configuration in which the movable valve body is in constant contact with the fixed valve body, or a configuration in which the movable valve body is always away from the fixed valve body.

  In the above-described embodiment, the shock torque prevention valve device is arranged between the master cylinder and the release cylinder and separated from the release cylinder. However, the present invention is not limited to this, and FIG. As shown, the release cylinder 12A may include a shock torque preventing valve device 20 built therein.

  According to this configuration, since the shock torque preventing valve device 20 is built in the release cylinder 12A, it is not necessary to mount the release cylinder and the valve device when mounting to the vehicle, and only the release cylinder can be mounted. The workability can be greatly improved.

It is front sectional drawing of the valve apparatus for shock torque prevention which concerns on one Embodiment of this invention (state which the movable valve body and the fixed valve body are contact | abutting). It is a front sectional view of the valve device for shock torque prevention concerning one embodiment of the present invention (state where a movable valve element and a fixed valve element are separated). It is the figure which looked at the inside of an inner hole from the left side of FIG. It is an external appearance perspective view which shows a movable valve body. (A) is a figure for demonstrating the function of a stopper part, (b) is the figure which expanded the check valve part of (a). It is a fragmentary sectional view (front view) which shows the release cylinder which incorporates the valve apparatus for shock torque prevention which concerns on one Embodiment of this invention. It is front sectional drawing of the conventional shock torque prevention valve. It is front sectional drawing which shows the bending deformation state of the non-return valve in the conventional shock torque prevention valve.

Explanation of symbols

10 Clutch pedal 11 Master cylinder 12, 12A Release cylinder 14 Passage 20 Shock torque preventing valve device 50 Inner hole 53a Large diameter throttle hole (first hole)
54 Check valve 55 Fixed valve body (valve body)
55a Valve hole (second hole)
57 Movable valve body 59 Valve body 71 Stopper 72 Relief passage

Claims (6)

Between the master cylinder operated by the clutch pedal and the release cylinder that moves the clutch by the hydraulic pressure of the hydraulic fluid, it is arranged in a passage that allows hydraulic fluid to pass in both directions, and in the recirculation direction that returns from the release cylinder to the master cylinder. A shock torque preventing valve device for preventing shock torque of the clutch by restricting the flow rate of the hydraulic fluid of
A valve body having an inner hole constituting a part of the passage;
A valve body provided in the inner hole and formed with a first hole for passing hydraulic fluid in both directions and a second hole for passing hydraulic fluid in a direction opposite to the reflux direction;
The valve body is held at the upstream side in the return direction of the valve body so as to be able to be bent and deformed, and when the hydraulic fluid passes in the return direction, it is pressed by the hydraulic fluid around the second hole of the valve body to close the second hole, A check valve that opens the second hole when hydraulic fluid passes in the opposite direction;
A valve device for preventing shock torque of a clutch, comprising: a stopper portion provided on the valve body side for regulating the amount of deformation of the check valve.   2. The valve device for preventing shock torque of a clutch according to claim 1, wherein the stopper portion is formed with a relief passage through which hydraulic fluid that has passed through the second hole in a direction opposite to the recirculation direction is formed. Valve device for preventing shock torque of clutch.   The valve device for shock torque prevention of the clutch according to claim 1 or 2, wherein the second hole is arranged at a constant radius from an axial center of the inner hole, and the check valve is formed in an annular shape. The inner peripheral side of the annular check valve is held by the valve body, and the stopper portion is provided on the valve main body side at a position where the outer peripheral side comes into contact with the outer peripheral portion of the check valve. A valve device for preventing shock torque of a clutch.   4. The clutch device for preventing shock torque of a clutch according to claim 1, wherein a plurality of the second holes are provided along a circumferential direction of the annular check valve. Valve device for preventing shock torque.   5. The valve device for preventing shock torque of a clutch according to claim 4, wherein a plurality of the stopper portions are provided so as to jump out along a circumferential direction of the annular check valve, and a relief passage is provided between the stopper portions adjacent to each other. A valve device for preventing shock torque of a clutch, wherein:   A release cylinder incorporating the clutch shock torque preventing valve device according to any one of claims 1 to 5.

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