Power transmission device

Abstract

The present application provides a power transmission device that enables smooth clutch operation in a state where engine braking is generated. A pressure member (5a, 5b) includes a first pressure member that is movable in a direction in which contact pressure is generated on a drive-side clutch plate (6) and a driven-side clutch plate (7) by pressing force of a link member (9), a second pressure member that is movable in a direction in which contact pressure on the drive-side clutch plate and the driven-side clutch plate is released by actuation force of an actuation member (10), and an anti-torque transmission cam that moves the second pressure member relative to the first pressure member to allow the contact pressure between the drive-side clutch plate and the driven-side clutch plate to be maintained when a rotational force is input to a clutch member (4) via an output shaft (3) during movement of a weight member (8) from an outer diameter position to an inner diameter position and movement of the first pressure member following the link member.

Description

[0001] The present application is a divisional application of the patent application for which application number is 201980080216.4 (international application number: PCT / JP2019 / 047409; filing date: December 04, 2019; invention name: Power transmission device). TECHNICAL FIELD

[0002] The present application relates to a power transmission device that can appropriately transmit or stop transmitting the rotational power of an input member to an output member. BACKGROUND

[0003] Generally, a motorcycle has a power transmission device for appropriately transmitting or stopping transmitting the driving force of an engine to a transmission and drive wheels. The power transmission device includes an input member coupled to an engine side, an output member coupled to a transmission and drive wheels side, a clutch member coupled to the output member, and a pressure member movable toward or away from the clutch member. The power transmission device is configured to transmit power by moving the pressure member toward the clutch member to press the driving side clutch plate and the driven side clutch plate against each other, and configured to stop transmitting power by moving the pressure member away from the clutch member to release the pressing contact force between the driving side clutch plate and the driven side clutch plate.

[0004] In the existing power transmission device, as disclosed in, for example, Patent Literature 1, a power transmission device including a weight member has been proposed. The weight member can move from a radially inner side position to a radially outer side position in a groove portion to press the driving side clutch plate and the driven side clutch plate against each other by centrifugal force generated due to rotation of a clutch housing. With the existing power transmission device, because the clutch housing rotates as the engine is driven, centrifugal force can be applied to the weight member, and the driving force of the engine can be transmitted to the wheels by pressing the driving side clutch plate and the driven side clutch plate against each other.

[0005] Another existing power transmission device, as disclosed in, for example, Patent Literature 2, has a cam mechanism composed of an elongated hole 32 and a pin 30. Even when the weight member is located at the radially inner side position, the power transmission device can press the driving side clutch plate and the driven side clutch plate against each other by moving the clutch hub 13 in the axial direction while rotating the clutch hub 13 using the cam composed of the elongated hole 32 and the pin 30, thereby moving the pressing flange 28 toward the clutch plate, to apply engine braking.

[0006] Prior Art Documents

[0007] Patent Literature

[0008] Patent Literature 1: Japanese Patent Application Laid-Open No. 2017-155884

[0009] Patent Literature 2: Japanese Patent Application Laid-Open No. 62-143827 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] In the existing power transmission device, when engine braking is to be applied, the cam mechanism composed of the elongated hole 32 and the pin 30 can be used to press the drive-side clutch plate and the driven-side clutch plate against each other to engage the clutch, and the power at the wheel side can be transmitted to the engine side. However, the existing power transmission device has a problem that when the clutch is operated to release the pressing contact force between the clutch plates (disengage the clutch) in the state where engine braking is applied, the clutch operation amount becomes large, and the clutch cannot be smoothly operated.

[0012] The present application is made in consideration of this situation, and aims to provide a power transmission device that can allow smooth clutch operation in the state where engine braking is applied.

[0013] SOLUTION TO THE PROBLEM

[0014] According to the invention of the first aspect, a power transmission apparatus includes: a clutch housing that rotates together with an input member that rotates by a driving force of an engine of a vehicle, and a plurality of drive-side clutch plates attached to the clutch housing; a clutch member to which a plurality of driven-side clutch plates that alternate with the drive-side clutch plates of the clutch housing are attached, and that is coupled to an output member that is capable of rotating a wheel of the vehicle; a pressure member that is movable between an operating position at which the pressure member presses the drive-side clutch plates and the driven-side clutch plates against each other so as to be capable of transmitting the driving force of the engine to the wheel, and a non-operating position at which the pressure member releases pressing contact force between the drive-side clutch plates and the driven-side clutch plates so as to be capable of stopping transmission of the driving force of the engine to the wheel; a weight member that is disposed in a groove portion that extends in a radial direction of the clutch housing, and that is movable in the groove portion from a radially inner side position to a radially outer side position due to centrifugal force that is generated as the clutch housing rotates; a link member that is capable of moving the pressure member from the non-operating position to the operating position as the weight member moves from the radially inner side position to the radially outer side position; and an actuation member that is capable of moving the pressure member in a direction in which pressing contact force between the drive-side clutch plates and the driven-side clutch plates is capable of being released. The pressure member includes: a first pressure member that is movable in a direction in which the first pressure member presses the drive-side clutch plates and the driven-side clutch plates against each other by receiving pressing force of the link member; a second pressure member that is movable in a direction in which the second pressure member releases pressing contact force between the drive-side clutch plates and the driven-side clutch plates by receiving actuation force of the actuation member; and a reverse torque transmission cam that moves the second pressure member relative to the first pressure member to keep the drive-side clutch plates and the driven-side clutch plates pressed against each other when rotational force is input to the clutch member via the output member during movement of the weight member from the radially outer side position to the radially inner side position and movement of the first pressure member following the link member.

[0015] According to the invention of the second aspect, in the power transmission apparatus of the first aspect, a direction in which the second pressure member moves by the reverse torque transmission cam and a direction in which the second pressure member moves due to actuation of the actuation member are opposite to each other.

[0016] According to the invention of the third aspect, in the power transmission apparatus according to the first or second aspect, the counter-torque transmission cam is formed in a peripheral edge portion of each of the first pressure member and the second pressure member.

[0017] According to the invention of the fourth aspect, in the power transmission apparatus according to any one of the first to third aspects, the counter-torque transmission cam is capable of moving the second pressure member by pressing a sliding region of the second pressure member on which the drive-side clutch plate and the driven-side clutch plate slide.

[0018] According to the invention of the fifth aspect, the power transmission apparatus according to any one of the first to fourth aspects includes a release spring capable of holding the pressure member in the non-working position, the release spring being compressed as the link member moves and the pressure member moves from the non-working position toward the working position, and capable of applying urging force while allowing the link member and the pressure member to move until the drive-side clutch plate and the driven-side clutch plate reach an engaged state before being pressed against each other; a clutch spring compressed during movement of the link member after the drive-side clutch plate and the driven-side clutch plate reach the engaged state, and capable of applying pressing contact force between the drive-side clutch plate and the driven-side clutch plate while allowing the link member to move; and a buffer member interposed between the first pressure member and the second pressure member, and capable of applying urging force while allowing the link member to move by being compressed during movement of the link member and the pressure member from the non-working position toward the working position.

[0019] According to the invention of the sixth aspect, in the power transmission apparatus according to the fifth aspect, the buffer member is a wave spring constituted by a C-shaped member having a cutout portion in a part of a ring shape thereof, and the counter-torque transmission cam is capable of supporting an outer peripheral surface of the wave spring.

[0020] According to the invention of the seventh aspect, the power transmission apparatus according to any one of the first to sixth aspects includes a torque transmission portion formed in each of the first pressure member and the second pressure member, and capable of transmitting rotational force that has been transmitted to the second pressure member to the first pressure member without using the counter-torque transmission cam.

[0021] Advantages of the Invention

[0022] With the invention according to the first aspect, it is possible to allow the clutch operation to be smoothly performed in a state in which engine braking is applied, because the pressure member includes: a first pressure member that is able to move in a direction in which the first pressure member presses the drive-side clutch plate and the driven-side clutch plate against each other by receiving pressing force of the linkage member; a second pressure member that is able to move in a direction in which the second pressure member releases pressing contact force between the drive-side clutch plate and the driven-side clutch plate by receiving actuation force of the actuation member; and a reverse torque transmission cam that moves the second pressure member relative to the first pressure member to keep the drive-side clutch plate and the driven-side clutch plate pressed against each other when rotational force is input to the clutch member via the output member during movement of the weight member from the radially outer position to the radially inner position and movement of the first pressure member following the linkage member.

[0023] With the invention according to the second aspect, it is possible to make an actuation amount caused by the actuation member smaller when the clutch operation is performed by using the actuation member in a state in which engine braking is applied, because the moving direction in which the second pressure member moves by the reverse torque transmission cam and the moving direction in which the second pressure member moves due to actuation of the actuation member are opposite to each other.

[0024] With the invention according to the third aspect, it is possible to generate greater thrust due to the cam and to more reliably press the drive-side clutch plate and the driven-side clutch plate against each other when engine braking is to be applied, because the reverse torque transmission cam is formed in a peripheral edge portion of each of the first pressure member and the second pressure member.

[0025] With the invention according to the fourth aspect, it is possible to effectively convert thrust generated by the cam into pressing contact force between the drive-side clutch plate and the driven-side clutch plate and to more reliably press the drive-side clutch plate and the driven-side clutch plate against each other when engine braking is to be applied, because the reverse torque transmission cam is able to move the second pressure member by pressing a sliding region of the second pressure member on which the drive-side clutch plate and the driven-side clutch plate slide.

[0026] With the invention according to the fifth aspect, it is possible to suppress a sudden feeling at the time of power transmission and to improve operability, because the power transmission device includes, in addition to the release spring and the clutch spring, a buffer member interposed between the first pressure member and the second pressure member and capable of applying urging force while allowing movement of the link member, by being compressed during movement of the link member and movement of the pressure member from the non-working position toward the working position.

[0027] With the invention according to the sixth aspect, it is possible to provide the counter-torque transmission cam with a function of allowing the second pressure member to hold the driving-side clutch plate and the driven-side clutch plate pressed against each other and a function of preventing the wave spring from expanding in a radially outward direction by receiving centrifugal force when supporting the wave spring, because the buffer member is a wave spring constituted by a C-shaped member having a cutout portion in a part of the annular shape thereof, and the counter-torque transmission cam is capable of supporting an outer peripheral surface of the wave spring.

[0028] With the invention according to the seventh aspect, it is possible to allow stable power transmission, because the power transmission device includes a torque transmission portion formed in each of the first pressure member and the second pressure member and capable of transmitting rotational force that has been transmitted to the second pressure member to the first pressure member without using the counter-torque transmission cam. BRIEF DESCRIPTION OF DRAWINGS

[0029] [ Figure 1 ] is an external view of a power transmission device according to an embodiment of the invention.

[0030] [ Figure 2 ] is a cross-sectional view showing an internal structure of the power transmission device (a longitudinal cross-sectional view at a position where the release spring is arranged).

[0031] [ Figure 3 ] is a cross-sectional view showing an internal structure of the power transmission device (a longitudinal cross-sectional view at a position where the clutch spring is arranged).

[0032] [ Figure 4 ] is a perspective view of a clutch housing of the power transmission device.

[0033] [ Figure 5 ] is a three-side view of a clutch member of the power transmission device.

[0034] [ Figure 6 ] is a three-side view of a first pressure member of the power transmission device.

[0035] [ Figure 7 ] is a three-side view of a second pressure member of the power transmission device.

[0036] [ Figure 8 ] is a perspective view showing the clutch member, the first pressure member, and the second pressure member of the power transmission device before assembly.

[0037] [ Figure 9 ] is a perspective view showing the clutch member, the first pressure member, and the second pressure member of the power transmission device before assembly.

[0038] [ Figure 10 ] is a perspective view showing the clutch member, the first pressure member, and the second pressure member of the power transmission device after assembly.

[0039] [ Figure 11 ] is a schematic view showing the function of the press contact auxiliary cam of the power transmission device.

[0040] [ Figure 12 ] is a schematic view showing the function of the reverse torque limiter cam of the power transmission device.

[0041] [ Figure 13 ] is a plan view of the first pressure member and the second pressure member of the power transmission device assembled together, showing a state in which one side surface of the protruding portion and the first contact surface (torque transmission portion) are in contact with each other.

[0042] [ Figure 14 ] is a plan view of the first pressure member and the second pressure member of the power transmission device assembled together, showing a state in which the other side surface of the protruding portion and the second contact surface (movement amount limiting portion) are in contact with each other.

[0043] [ Figure 15 ] is a schematic view showing the function of the reverse torque transmission cam of the power transmission device in a state before the reverse torque transmission cam starts to work.

[0044] [ Figure 16 ] is a schematic view showing the function of the reverse torque transmission cam of the power transmission device in a state after the reverse torque transmission cam starts to work.

[0045] [ Figure 17 ] is a plan view and a side view of the buffer member of the power transmission device.

[0046] [ Figure 18 ] is a perspective view of the buffer member.

[0047] [ Figure 19 ] is a longitudinal sectional view of the power transmission device according to another embodiment of the present application (a longitudinal sectional view at a position where the release spring is arranged).

[0048] [ Figure 20FIG. 1 is a longitudinal sectional view of a power transmission device according to a first embodiment of the present application (a longitudinal sectional view at a position where a clutch spring is arranged).

[0049] [ Figure 21 FIG. 2 is a longitudinal sectional view of a power transmission device according to a second embodiment of the present application (a longitudinal sectional view at a position where a release spring is arranged).

[0050] [ Figure 22 FIG. 3 is a longitudinal sectional view of a power transmission device according to a third embodiment of the present application (a longitudinal sectional view at a position where a clutch spring is arranged).

[0051] [ Figure 23 FIG. 4 is a longitudinal sectional view of a power transmission device according to a fourth embodiment of the present application (a longitudinal sectional view at a position where a release spring is arranged).

[0052] LIST OF REFERENCE NUMERALS

[0053] 1 input gear (input member)

[0054] 2 clutch housing

[0055] 2a cutout

[0056] 2b groove portion

[0057] 3 output shaft (output member)

[0058] 4 clutch member

[0059] 4a inclined surface (press contact assisting cam)

[0060] 4b inclined surface (reverse torque limiter cam)

[0061] 4c flange surface

[0062] 4d insertion hole

[0063] 4e boss portion

[0064] 4f spline fitting portion

[0065] 4g through hole

[0066] 4h attachment portion

[0067] 5a first pressure member

[0068] 5a inclined surface (press contact assisting cam)

[0069] 5ab inclined surface (reverse torque limiter cam)

[0070] 5ac insertion hole

[0071] 5ad attachment recessed portion

[0072] 5ae attachment recessed portion

[0073] 5b second pressure member

[0074] 5ba flange surface

[0075] 5bb protruding portion

[0076] 6 drive side clutch plate

[0077] 7 driven side clutch plate

[0078] 8 weight member

[0079] 9 linkage member

[0080] 9a first linkage member

[0081] 9b second linkage member

[0082] 10 actuation member

[0083] 11 clutch spring

[0084] 12 release spring

[0085] 13 cushion member

[0086] 14 coned disc spring

[0087] C bearing retaining member

[0088] K slot portion

[0089] K1 cam surface

[0090] K2 wall surface

[0091] T protruding portion

[0092] T1 cam surface

[0093] T2 wall surface

[0094] F protruding portion

[0095] G protruding portion

[0096] G1 first contact surface

[0097] G2 second contact surface DETAILED DESCRIPTION

[0098] Hereinafter, embodiments of the present application will be described in detail with reference to the drawings.

[0099] The power transmission device according to the present embodiment is a device arranged in a vehicle such as a motorcycle, and functions to appropriately transmit or stop transmission of driving force of an engine to a transmission or toward a drive wheel side. As shown in Figures 1 to 10 the power transmission device mainly includes: a clutch housing 2 in which an input gear 1 (input member) that rotates by driving force of an engine of a vehicle is formed; a clutch member 4; a first pressure member 5a; a second pressure member 5b; a plurality of drive side clutch plates 6; a plurality of driven side clutch plates 7; a weight member 8 that is composed of a steel ball member that can move (roll) in a radial direction of the clutch housing 2; a link member 9; and an actuating member 10 that can be actuated by hand or by an actuator (not shown). The symbol B1 in the figure shows a ball bearing, and the symbol B2 shows a thrust bearing.

[0100] When input of driving force (rotational force) transmitted from the engine is performed, the input gear 1 can rotate around the output shaft 3. The input gear 1 is coupled to the clutch housing 2 via a rivet R or the like. The clutch housing 2 includes a cylindrical member that is open at the right side in Figure 2 and Figure 3 and is coupled to the input gear 1. The clutch housing 2 can rotate together with rotation of the input gear 1 due to the driving force of the engine.

[0101] As shown in Figure 1 and Figure 4 a plurality of cutouts 2a are formed in the clutch housing 2 to be arranged in a circumferential direction, and a plurality of drive side clutch plates 6 are attached to fit to the cutouts 2a. Each of the drive side clutch plates 6 is composed of a substantially annular plate material, and is configured to be able to rotate together with rotation of the clutch housing 2 and slide in an axial direction (left-right direction in Figure 2 and Figure 3 ).

[0102] Further, as shown in Figure 4 a plurality of groove portions 2b extending in a radial direction are formed in a bottom surface of the clutch housing 2. The weight member 8 is arranged in each of the groove portions 2b. The weight member 8 is located at a radially inner side position in a state in which the clutch housing 2 is stopped (engine stopped or idling state) and a state in which the clutch housing 2 rotates at a low speed. The weight member 8 is located at a radially outer side position in a state in which the clutch housing 2 rotates at a high speed.

[0103] The clutch member 4 has a plurality of driven side clutch plates 7 attached thereto, which are alternately formed with the drive side clutch plates 6 of the clutch housing 2. The clutch member 4 is coupled to the output shaft 3 (output member) that can rotate a wheel of the vehicle. As shown in Figure 5As shown, in the clutch member 4, a flange surface 4c is formed along its peripheral edge. The clutch member 4 is configured such that the output shaft 3 is inserted into the insertion hole 4d formed at its center, and the clutch member 4 and the output shaft 3 are interconnected in the rotational direction due to the meshing of gears formed therein.

[0104] like Figure 5 and Figure 9 As shown, in the clutch member 4 according to this embodiment, an inclined surface 4a constituting a pressing contact auxiliary cam and an inclined surface 4b constituting a torque limiter cam are formed. Furthermore, a spline engagement portion 4f is formed on the outer peripheral surface of the clutch member 4, and the driven-side clutch plate 7 is attached to the spline engagement portion 4f via a spline engagement.

[0105] like Figures 8 to 10 As shown, the first pressure member 5a and the second pressure member 5b are assembled together with the clutch member 4. A plurality of drive-side clutch plates 6 and driven-side clutch plates 7, in an alternating stacked state, are attached between the flange surface 5ba of the second pressure member 5b and the flange surface 4c of the clutch member 4. A boss portion 4e protruding in the axial direction is formed at the center of the clutch member 4, and an insertion hole 4d is formed in the longitudinal direction inside the boss portion 4e.

[0106] The clutch component 4, the first pressure member 5a, and the second pressure member 5b are assembled by inserting the boss portion 4e of the clutch component 4 into the insertion hole 5ac of the first pressure member 5a, and simultaneously inserting the second pressure member 5b between the clutch component 4 and the first pressure member 5a. The clutch component 4 has a through hole 4g ​​for inserting the protruding portion 5bb protruding from the second pressure member 5b, and in the assembled state of the first pressure member 5a and the second pressure member 5b, an attachment portion 4h for attaching the bearing retaining member C is formed.

[0107] The pressure members (5a, 5b) are movable between a working position and a non-working position. In the working position, the pressure members press the drive-side clutch plate 6 and the driven-side clutch plate 7 together to transmit the engine's driving force to the wheels. In the non-working position, the pressure members release the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 to stop transmitting the engine's driving force to the wheels. In this embodiment, the pressure members (5a, 5b) are composed of a first pressure member 5a and a second pressure member 5b.

[0108] The first pressure member 5a can move in a direction that causes the driving-side clutch plate 6 and the driven-side clutch plate 7 to press against each other by receiving the pressing force of the linkage member 9. For example... Figure 6 and Figure 8As shown, the first pressure member 5a has an inclined surface 5aa constituting a pressing contact auxiliary cam and an inclined surface 5ab constituting a torque limiter cam. The first pressure member 5a is composed of a cylindrical member with an insertion hole 5ac formed at its center, and the boss portion 4e of the clutch member 4 is inserted into the insertion hole 5ac for assembly.

[0109] Furthermore, in the first pressure member 5a, there are attachment recesses 5ad for attaching the clutch spring 11 and attachment recesses 5ae for attaching the release spring 12. For example... Figure 2 and Figure 3 As shown, the clutch spring 11 is held between the first pressure member 5a and the linkage member 9 so that the clutch spring 11 can be compressed, and the release spring 12 is held between the first pressure member 5a and the bearing retaining member C so that the release spring 12 can be compressed.

[0110] The second pressure member 5b can move in the direction that causes the second pressure member 5b to release the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 by receiving the actuating force from the actuating member 10. For example... Figures 7 to 9 As shown, the second pressure member 5b is composed of an annular member, wherein a flange surface 5ba and a protruding portion 5bb are formed. When the first pressure member 5a, the second pressure member 5b and the clutch member 4 are assembled, the driving side clutch plate 6 and the driven side clutch plate 7, which are in a stacked state, are held between the flange surface 4c of the clutch member 4 and the flange surface 5ba of the second pressure member 5b.

[0111] When the first pressure member 5a and the second pressure member 5b are along Figure 2 and Figure 3 When the first pressure member 5a moves in direction B and reaches the working position, the driving-side clutch plate 6 and the driven-side clutch plate 7 press against each other to transmit the driving force of the vehicle's engine to the wheels. When the first pressure member 5a and the second pressure member 5b move along... Figure 2 and Figure 3 When the clutch moves in direction A and reaches the non-working position, the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 is released, thereby stopping the transmission of the vehicle's engine driving force to the wheels.

[0112] That is, when the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed together, the rotational force (engine driving force) input to the clutch housing 2 is transmitted to the wheel side via the output shaft 3 (output member). When the pressing contact between the driving-side clutch plate 6 and the driven-side clutch plate 7 is released, the rotational force (engine driving force) input to the clutch housing 2 can stop being transmitted to the output shaft 3 (output member).

[0113] Further, as shown in Figures 6 to 9 In the present embodiment, inclined surfaces 4a and 4b are formed in the clutch member 4, and inclined surfaces 5aa and 5ab are formed in the first pressure member 5a. In the assembled state of the first pressure member 5a, the second pressure member 5b, and the clutch member 4, the inclined surface 4a and the inclined surface 5aa face each other to constitute a press contact assisting cam, and the inclined surface 4b and the inclined surface 5ab face each other to constitute an anti-torque limiter cam.

[0114] As shown in Figure 11 When the rotational speed of the engine increases, the first pressure member 5a receives a rotational force in the direction a, and the rotational force input to the input gear 1 and the clutch housing 2 becomes able to be transmitted to the output shaft 3 via the clutch member 4 (the weight member 8 is in the radially outer position). Therefore, due to the function of the press contact assisting cam, a force in the direction c in the drawing is generated in the first pressure member 5a. Therefore, the first pressure member 5a and the second pressure member 5b move in one direction (direction B in Figure 2 and Figure 3 , so that the flange surface 5ba of the second pressure member 5b is further moved toward the flange surface 4c of the clutch member 4, and the first pressure member 5a and the second pressure member 5b increase the press contact force between the drive side clutch plate 6 and the driven side clutch plate 7.

[0115] On the other hand, during the vehicle running, when the rotational speed of the output shaft 3 exceeds the rotational speed of the input gear 1 and the clutch housing 2 and an anti-torque in the direction b in Figure 12 is generated, due to the function of the anti-torque limiter cam, the first pressure member 5a moves in the direction d in the drawing to release the press contact force between the drive side clutch plate 6 and the driven side clutch plate 7. Therefore, it is possible to avoid damage to the power transmission device and the power source (engine side) due to the anti-torque.

[0116] The weight member 8 is arranged in a groove portion 2b (see Figure 4 ) extending in the radial direction of the clutch housing 2. Due to the centrifugal force generated with the rotation of the clutch housing 2, the weight member 8 moves in the groove portion 2b from the radially inner position to the radially outer position to be able to press the drive side clutch plate 6 and the driven side clutch plate 7 against each other. That is, the rolling surface (bottom surface) on which the weight member 8 rolls in the groove portion 2b has an upward inclination angle from the radially inner position toward the radially outer position. When the clutch housing 2 is stopped, the weight member 8 is held in the radially inner position due to the urging force of the release spring 12. When the clutch housing 2 rotates, the centrifugal force acts on the weight member 8, and when the clutch housing 2 reaches a predetermined rotational speed, the weight member 8 moves to the radially outer position along the upward inclination angle.

[0117] The linkage member 9 is composed of a first linkage member 9a and a second linkage member 9b arranged in the clutch housing 2. The linkage member 9 is fitted and coupled to the clutch housing 2, can rotate together with the clutch housing 2, and can move in the left-right direction in Figure 2 and Figure 3 The thrust bearing B2 is interposed and attached between the first linkage member 9a and the second linkage member 9b, and the first linkage member 9a and the second linkage member 9b can rotate independently. When the weight member 8 moves from the radially inner position to the radially outer position, the first linkage member 9a and the second linkage member 9b move together in the direction B in Figure 2 and Figure 3 and can press the first pressure member 5a and the second pressure member 5b to move the first pressure member 5a and the second pressure member 5b from the non-working position to the working position.

[0118] The actuating member 10 is composed of a member that can be operated by hand or by using an actuator (see Figure 2 and Figure 3 ) and moves the first pressure member 5a and the second pressure member 5b in one direction (in the direction A in Figure 2 and Figure 3 so that the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 can be released. When a shift operation is performed (for example, by operation of a clutch pedal, a clutch lever, or the like of a vehicle, or by work of an actuator), the actuating member 10 moves in the direction A in Figure 2 and Figure 3 to contact the end of the protruding portion 5bb of the second pressure member 5b via the bearing holding member C and move the second pressure member 5b from the working position to the non-working position. Thus, the actuating member 10 can disconnect the clutch (stop the power transmission) by releasing the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7.

[0119] Further, as Figure 2As shown in the figure, the bearing holding member C according to the present embodiment holds the release spring 12 between the bearing holding member C and the first pressure member 5a. The release spring 12 can hold the first pressure member 5a in the non-working position and be compressed when the linkage member 9 moves and the first pressure member 5a and the second pressure member 5b move from the non-working position toward the working position. The release spring 12 can apply urging force while allowing the linkage member 9, the first pressure member 5a, and the second pressure member 5b to move until the driving-side clutch plate 6 and the driven-side clutch plate 7 reach the engaged state (a state in which the distance between the driving-side clutch plate 6 and the driven-side clutch plate 7 is zero, and immediately before power transmission due to pressing contact) before being pressed against each other.

[0120] The clutch spring 11 is constituted by a coil spring interposed between the linkage member 9 and the first pressure member 5a. When the linkage member 9 moves, the clutch spring 11 can press the first pressure member 5a and the second pressure member 5b to move the pressure members (5a, 5b) in one direction, so that the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other. In addition, when the actuation member 10 is operated, the clutch spring 11 can absorb the pressing force exerted by the first pressure member 5a and the second pressure member 5b on the linkage member 9.

[0121] The clutch spring 11 according to the present embodiment moves together with the first pressure member 5a and the second pressure member 5b without being compressed (deformed) until the driving-side clutch plate 6 and the driven-side clutch plate 7 reach the engaged state described above. After the driving-side clutch plate 6 and the driven-side clutch plate 7 reach the engaged state, the clutch spring 11 is compressed in the course of movement of the linkage member 9 and can apply pressing contact force between the driving-side clutch plate 6 and the driven-side clutch plate 7 while allowing the linkage member 9 to move.

[0122] That is, when the weight member 8 moves from the radially inner position to the radially outer position as the clutch housing 2 rotates and the linkage member 9 is pressed by the weight member 8, the pressing force is transmitted to the first pressure member 5a and the second pressure member 5b via the clutch spring 11, moving the first pressure member 5a and the second pressure member 5b in the direction B in FIG. Figure 2 and Figure 3 , and pressing the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other. When the actuation member 10 is actuated in this state, although the first pressure member 5a and the second pressure member 5b move in the direction A in the figure due to the pressing force of the actuation member 10, the pressing force applied to the linkage member 9 is absorbed by the clutch spring 11, and the position of the linkage member 9 (the position of the weight member 8) is maintained.

[0123] Here, the power transmission device according to this embodiment includes a reverse torque transmission cam (cam surfaces K1 and T1). During the movement of the weight member 8 from a radially outer position to a radially inner position and the first pressure member 5a following the movement of the linkage member 9, when rotational force is input to the clutch member 4 via the output shaft 3, the reverse torque transmission cam causes the second pressure member 5b to move relative to the first pressure member 5a, thereby maintaining the driving-side clutch plate 6 and the driven-side clutch plate 7 pressed against each other. Figures 6 to 9 As shown, the anti-torque transmission cam is composed of cam surfaces (K1, T1), which are integrally formed in the mating surfaces (matting surfaces when engaged) of the first pressure member 5a and the second pressure member 5b, respectively.

[0124] The cam surface K1 is composed of a plurality of inclined surfaces arranged circumferentially along the outer edge portion of the first pressure member 5a. The cam surface K1 is formed in one end face of each of a plurality of groove portions K formed annularly along the outer edge portion of the first pressure member 5a. That is, the plurality of groove portions K are formed in the outer edge portion of the first pressure member 5a arranged circumferentially, and one end face of each groove portion K is an inclined surface constituting the cam surface K1 of the anti-torque transmission cam. The other end face of each groove portion K is a wall surface K2 extending in the axial direction of the first pressure member 5a.

[0125] The cam surface T1 is composed of a plurality of inclined surfaces arranged along the entire circumference of the bottom surface of the second pressure member 5b. The cam surface T1 is formed in one end face of each of a plurality of protrusions T formed annularly along the outer periphery of the second pressure member 5b. That is, the plurality of protrusions T are formed in the second pressure member 5b in a circumferential arrangement, and one end face of each protrusion T is an inclined surface of the cam surface T1 constituting the anti-torque transmission cam. The other end face of each protrusion T is a wall surface T2 extending in the axial direction of the second pressure member 5b.

[0126] like Figure 15 As shown, when the protruding portion T engages with the slot portion K to engage the first pressure member 5a and the second pressure member 5b, the cam surface K1 and the cam surface T1 face each other to form a counter-torque transmission cam, and the wall surface K2 and the wall surface T2 face each other with a predetermined distance between them. Therefore, when the vehicle is in motion, as the engine speed decreases, the weight member 8 moves from the radially outer position to the radially inner position, and the first pressure member 5a moves along with the linkage member 9, when a rotational force is input to the clutch member 4 via the output shaft 3, the first pressure member 5a and the second pressure member 5b rotate relative to each other. Therefore, due to the function of the cam surface K1 and the cam surface T1, the second pressure member 5b can be moved along... Figure 2and Figure 3 moves in the direction B in FIG. 12 and FIG. 13 relative to the first pressure member 5a to maintain the pressing contact of the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other.

[0127] That is, when the vehicle travels along a downward slope, as the rotational speed of the engine decreases and the weight member 8 moves from the radially outer position to the radially inner position, the first pressure member 5a follows the weight member 8 to move in the direction A in FIG. 12 and FIG. 13. Figure 2 and Figure 3 Then, when the rotational force of the wheels is transmitted to the clutch member 4 via the output shaft 3, the first pressure member 5a and the second pressure member 5b rotate relative to each other to generate a cam function between the cam surface K1 and the cam surface T1, and the second pressure member 5b moves in the direction B in FIG. 12 and FIG. 13 to maintain the pressing contact of the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other, so that engine braking can be applied. Figure 2 and Figure 3 When the actuation member 10 is operated from the state in which engine braking is applied, with a hand or by using an actuator, the second pressure member 5b that has been maintaining the pressing contact of the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other moves in the direction A in FIG. 12 and FIG. 13, so that the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 can be released to disconnect the clutch.

[0128] When the actuation member 10 is operated from the state in which engine braking is applied, with a hand or by using an actuator, the second pressure member 5b that has been maintaining the pressing contact of the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other moves in the direction A in FIG. 12 and FIG. 13, so that the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 can be released to disconnect the clutch. Figure 2 and Figure 3 At this time, in the present embodiment, the moving direction of the second pressure member 5b by the reverse torque transmission cam (the direction B in the figure) and the moving direction of the second pressure member 5b due to the actuation of the actuation member 10 (the direction A in the figure) are opposite to each other. Therefore, when the clutch is to be disconnected (the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 is released) in the state in which engine braking is applied, it is possible to avoid the operation amount of the actuation member 10 from becoming excessively large. Figure 2 and Figure 3 The reverse torque transmission cam according to the present embodiment is formed in the outer peripheral edge portion of each of the first pressure member 5a and the second pressure member 5b. The reverse torque transmission cam can move the second pressure member 5b by pressing the sliding region H (a region in which a pressing contact force acts) of the second pressure member 5b on which the drive-side clutch plate 6 and the driven-side clutch plate 7 slide (see and

[0129] ). That is, the radial outermost portion of the first pressure member 5a and the second pressure member 5b generates a thrust of the second pressure member 5b due to the reverse torque transmission cam, and this thrust is applied to the sliding region H of the drive-side clutch plate 6 and the driven-side clutch plate 7. Figure 2 and Figure 3

[0130] If the linkage member 9 and the weight member 8 are separated from each other during the reverse torque transmission cam operation, the linkage member 9 can not be able to follow the movement of the weight member 8 quickly even if the weight member 8 moves between the radially inner position and the radially outer position later with the rotation of the clutch housing 2. In contrast, with the present embodiment, the first pressure member 5a follows the linkage member 9 to be able to maintain the contact between the linkage member 9 and the weight member 8 even during the reverse torque transmission cam operation, and thus the linkage member 9 is able to follow the movement of the weight member 8 stably.

[0131] The reverse torque transmission cam (cam composed of the cam surface K1 and the cam surface T1) according to the present embodiment can start to operate before the reverse torque limiter cam (cam composed of the inclined surface 4b and the inclined surface 5ab) starts to operate. That is, the clearance (size of the gap) between the cam surface K1 and the cam surface T1 is smaller than the clearance (size of the gap) between the inclined surface 4b and the inclined surface 5ab, and the reverse torque transmission cam can start to operate before the reverse torque limiter cam starts to operate.

[0132] Further, the power transmission device according to the present embodiment includes a torque transmission portion that is formed in each of the first pressure member 5a and the second pressure member 5b and that can transmit the rotational force that has been transmitted to the second pressure member 5b to the first pressure member 5a without using the reverse torque transmission cam (cam surface K1 and cam surface T1), and a movement amount limiting portion that is formed in each of the first pressure member 5a and the second pressure member 5b and that limits the movement amount of the second pressure member 5b due to the reverse torque transmission cam (cam surface K1 and cam surface T1).

[0133] That is, as shown in Figure 6 and Figure 8 , a plurality of (three in the present embodiment) protruding portions F are integrally formed in the first pressure member 5a so as to be arranged at regular intervals in the circumferential direction. As shown in Figure 7 , Figure 8 and Figure 9 , inwardly extending protruding portions G are integrally formed in the second pressure member 5b. As shown in Figure 13 and Figure 14 , when the first pressure member 5a and the second pressure member 5b are assembled together, one protruding portion F is interposed between two protruding portions G, one side surface F1 of the protruding portion F and a contact surface (first contact surface G1) of one of the protruding portions G face each other, and the other side surface F2 of the protruding portion F and a contact surface (second contact surface G2) of the other of the protruding portions G face each other.

[0134] A side surface F1 of the protruding portion F formed in the first pressure member 5a and a first contact surface G1 of the protruding portion G formed in the second pressure member 5b constitute the torque transmission portion according to this embodiment. That is, when the first pressure member 5a and the second pressure member 5b move to the working position to press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other, and the clutch is engaged (driving force is transmitted), the wall surface K2 of the groove portion K and the wall surface T2 of the protruding portion T of the anti-torque transmission cam remain in a separated state (see...). Figure 15 ),like Figure 13 As shown, a side surface F1 of the protruding part F and a first contact surface G1 of the protruding part G are in contact with each other, and the rotational force of the second pressure member 5b can be received and transmitted to the first pressure member 5a.

[0135] The other side surface F2 of the protruding portion F formed in the first pressure member 5a and the second contact surface G2 of the other protruding portion G formed in the second pressure member 5b constitute the movement limiting portion according to this embodiment. That is, when a rotational force is input to the clutch member 4 via the output shaft 3, the first pressure member 5a and the second pressure member 5b rotate relative to each other. Therefore, the second pressure member 5b moves due to the cam function of the cam surface K1 of the groove portion K and the cam surface T1 of the protruding portion T of the anti-torque transmission cam (see...). Figure 16 When the movement reaches the set value, such as... Figure 14 As shown, the other side surface F2 of the protruding part F and the second contact surface G2 of the protruding part G are in contact with each other, and the rotation of the second pressure member 5b relative to the first pressure member 5a is restricted, thus limiting the amount of movement of the second pressure member 5b when the anti-torque transmission cam is working.

[0136] In this embodiment, the protruding portion F is formed in the first pressure member 5a, and the extended portion G is formed in the second pressure member 5b. Alternatively, the extended portion G may be formed in the first pressure member 5a, and the protruding portion F may be formed in the second pressure member 5b. In this case, one side surface F1 of the protruding portion F formed in the second pressure member 5b and the first contact surface G1 of the extended portion G formed in the first pressure member 5a constitute the torque transmission portion according to this embodiment. The other side surface F2 of the protruding portion F formed in the second pressure member 5b and the second contact surface G2 of the other extended portion G formed in the first pressure member 5a constitute the movement limiting portion according to this embodiment.

[0137] Further, the present embodiment includes a buffer member 13 interposed between the first pressure member 5a and the second pressure member 5b, and by being compressed (spring deformation) during movement of the link member 9 and movement of the first pressure member 5a and the second pressure member 5b from the non-working position toward the working position, can apply urging force while allowing movement of the link member 9 and the pressure members (5a, 5b). The buffer member 13 is composed of a spring set to a load at which the spring is compressed before the clutch spring 11 starts to be compressed. As shown in Figure 2 and Figure 3 The buffer member 13 is fitted at a surface at which the first pressure member 5a and the second pressure member 5b face each other (specifically, a surface at which the first pressure member 5a faces the second pressure member 5b).

[0138] More specifically, as shown in Figure 17 and Figure 18 The buffer member 13 is composed of a C-shaped wave spring having a cutout portion 13a in a part of the annular shape thereof, has a wavy shape with respect to the thickness direction t, and can generate an elastic force. The buffer member 13 is interposed between the first pressure member 5a and the second pressure member 5b, and by being compressed during movement of the link member 9 and movement of the first pressure member 5a and the second pressure member 5b from the non-working position toward the working position, can apply urging force while allowing movement of the link member 9.

[0139] With the buffer member 13, when the link member 9 starts to move, the pressing load (N) becomes the set load of the release spring 12, and the release spring 12 starts to deform (starts to be compressed). When the amount of movement of the link member 9 reaches a predetermined size, the buffer member 13 starts to deform (starts to be compressed). Subsequently, when the amount of movement of the link member 9 reaches a predetermined size, the pressing load (N) reaches the set load (P2) of the clutch spring 11, so that the clutch spring 11 starts to deform (starts to be compressed). Until the clutch spring 11 reaches the maximum load (upper limit of the working load), the clutch spring 11 continues to be compressed (continues to deform) due to movement of the link member 9.

[0140] Therefore, the buffer member 13 is continuously compressed (deformed) to allow movement of the link member 9 during an increase in the pressing load. Therefore, it is possible to reduce the dead zone in which the link member 9 stops, and to smoothly continuously move the weight member 8 and the link member 9. Therefore, with the buffer member 13, it is possible to suppress the impact at the time of engagement of the clutch, and to suppress the sudden feeling at the time of power transmission.

[0141] Further, the cushioning member 13 according to the present embodiment is arranged radially inward of the extended portion T of the reverse torque transmission cam. That is, the outer peripheral surface of the cushioning member 13 is supported by the extended portion T of the reverse torque transmission cam, and the extended portion T can prevent the diameter of the cushioning member 13 from increasing when a centrifugal force is generated in the cushioning member 13 as the first pressure member 5a and the second pressure member 5b rotate.

[0142] With the present embodiment, the pressure members (5a, 5b) include: the first pressure member 5a that can move in a direction such that the first pressure member 5a presses the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other by receiving the pressing force of the linkage member 9; the second pressure member 5b that can move in a direction such that the second pressure member 5b releases the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7 by receiving the actuation force of the actuation member 10; and the reverse torque transmission cam (K1, T1) that moves the second pressure member 5b relative to the first pressure member 5a to keep the drive-side clutch plate 6 and the driven-side clutch plate 7 pressed against each other when a rotational force is input to the clutch member 4 via the output shaft 3 during movement of the weight member 8 from the radially outer position to the radially inner position and movement of the first pressure member 5a following the linkage member 9.

[0143] The moving direction of the second pressure member 5b by the reverse torque transmission cam (K1, T1) and the moving direction of the second pressure member 5b due to the actuation of the actuation member 10 are opposite to each other. Therefore, when the clutch is operated by using the actuation member 10 in a state where engine braking is applied, it is possible to make the amount of actuation of the actuation member 10 smaller. Further, the reverse torque transmission cam (K1, T1) is formed in the peripheral edge portion of each of the first pressure member 5a and the second pressure member 5b. Therefore, it is possible to generate a larger cam thrust, and it is possible to more reliably press the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other when engine braking is to be applied.

[0144] Further, the reverse torque transmission cam (K1, T1) can move the second pressure member 5b by pressing the sliding region H for the drive-side clutch plate 6 and the driven-side clutch plate 7 to slide thereon of the second pressure member 5b. Therefore, it is possible to effectively convert the thrust generated by the cam into the pressing contact force between the drive-side clutch plate 6 and the driven-side clutch plate 7, and it is possible to more reliably press the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other when engine braking is to be applied.

[0145] The power transmission device includes, in addition to the release spring 12 and the clutch spring 11, a cushion member 13 that is interposed between the first pressure member 5a and the second pressure member 5b and that can apply urging force while allowing the link member 9 to move by being compressed during movement of the link member 9 and the pressure members (5a, 5b) from the non-working position toward the working position. Thus, it is possible to suppress a sudden feeling during power transmission and to improve operability.

[0146] Further, the cushion member 13 according to the present embodiment is a wave spring composed of a C-shaped member having a cutout portion 13a in a part of the annular shape thereof, and the counter-torque transmission cam (K1, T1) can support the outer peripheral surface of the wave spring. Thus, the counter-torque transmission cam (K1, T1) can have a function of allowing the second pressure member 5b to continue pressing the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other and a function of preventing the wave spring from expanding in the radially outward direction by receiving centrifugal force while supporting the wave spring.

[0147] Further, the power transmission device includes a torque transmission portion (one side surface F1 of the protruding portion F and the first contact surface G1 of the extending portion G) that is formed in each of the first pressure member 5a and the second pressure member 5b and that can transmit the rotational force that has been transmitted to the second pressure member 5b to the first pressure member 5a without using the counter-torque transmission cam (K1, T1). Thus, it is possible to stably perform power transmission.

[0148] With the above-described embodiment, the counter-torque transmission cam can move the second pressure member 5b in the direction toward the link member 9 to maintain contact between the link member 9 and the weight member 8. Thus, it is possible to press the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other to transmit the rotational force of the wheel side to the engine side to apply engine brake and to stably perform actuation with the weight member 8 when engine brake is applied.

[0149] The counter-torque transmission cam according to the present embodiment is composed of cam surfaces (K1, T1) that are integrally formed in the first pressure member 5a and the second pressure member 5b, respectively, and the cam surfaces (K1, T1) are formed on the mating surfaces of the first pressure member 5a and the second pressure member 5b, respectively. Thus, it is possible to reliably and smoothly move the second pressure member 5b with the counter-torque transmission cam.

[0150] Further, the power transmission device includes a press-contact assisting cam constituted by the inclined surface 4a of the clutch member 4 and the inclined surface 5aa of the first pressure member 5a facing each other, which increases the press-contact force between the driving-side clutch plate 6 and the driven-side clutch plate 7 when the rotational force input to the input gear 1 (input member) becomes transmittable to the output shaft 3 (output member). Therefore, in addition to the press-contact force due to the movement of the weight member 8 by the centrifugal force, the press-contact force due to the press-contact assisting cam can be applied, and the driving-side clutch plate 6 and the driven-side clutch plate 7 can be pressed against each other more smoothly and more reliably.

[0151] Further, the power transmission device includes a reverse torque limiter cam constituted by the inclined surface 4b of the clutch member 4 and the inclined surface 5ab of the first pressure member 5a facing each other, which can release the press-contact force between the driving-side clutch plate 6 and the driven-side clutch plate 7 when the rotational speed of the output shaft 3 (output member) exceeds the rotational speed of the input gear 1 (input member) and the clutch member 4 and the pressure members (5a, 5b) rotate relative to each other. Therefore, when the weight member 8 is in the radially outer position, excessive driving force can be prevented from being transmitted to the engine side via the input gear 1, and the reverse torque transmission cam can be reliably enabled because the reverse torque transmission cam is enabled before the reverse torque limiter cam starts to work.

[0152] Further, the present embodiment includes a reverse torque transmission cam which can move the second pressure member 5b to press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other when the rotational force is input to the clutch member 4 via the output shaft 3 (output member), and a torque transmission portion which is formed in each of the first pressure member 5a and the second pressure member 5b and can transmit the rotational force that has been transmitted to the second pressure member 5b to the first pressure member 5a without using the reverse torque transmission cam (cam surface K1 and cam surface T1). Therefore, by pressing the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other to transmit the rotational force of the wheel side to the engine side, engine braking can be applied, and stable power transmission can be performed when the weight member 8 moves to the radially outer position and the pressure members (5a, 5b) move to the working position.

[0153] Further, the power transmission device includes a movement amount limiting portion which is formed in each of the first pressure member 5a and the second pressure member 5b and limits the movement amount of the second pressure member 5b due to the reverse torque transmission cam. Therefore, the reverse torque transmission cam can be made to move the second pressure member 5b within a set range.

[0154] Further, the protruding portion F is formed in either one of the first pressure member 5a and the second pressure member 5b, the torque transmission portion is constituted by one side surface Fl of the protruding portion F and a first contact surface Gl that receives a rotational force by contacting the one side surface Fl, and the movement amount limiting portion is constituted by the other side surface F2 of the protruding portion F and a second contact surface G2 that can limit the movement amount by contacting the other side surface F2. Therefore, the protruding portion F can function as both the torque transmission portion and the movement amount limiting portion.

[0155] So far, the present embodiment has been described. However, the present application is not limited to this. For example, as shown in Figure 19 and Figure 20 The coned-disc spring 14 arranged between the first pressure member 5a and the second pressure member 5b can be used as a cushioning member. As shown in Figure 21 and Figure 22 The first pressure member 5a and the second pressure member 5b can not be provided with a cushioning member therebetween. Note that the power transmission device according to the present application can be applied to various multi-plate clutch power transmission devices in addition to motorcycles, automobiles, three- or four-wheeled ATVs, general-purpose machines, and the like.

[0156] Further, as shown in Figure 23 A cup-shaped bearing holding member C can be provided, the actuating member 10 can be engaged with an opening formed in the top of the bearing holding member C via a roller bearing Bl, and the pressure members (5a, 5b) can be moved in the left-right direction in the figure between an operating position and a non-operating position by being operated by an operator or by the work of an actuator. In this case, the release spring 12 is a coned-disc spring arranged between the second pressure member 5b and the bearing holding member C. In the figure, the symbol r represents an oil flow path r.

[0157] Industrial applicability

[0158] The pressure member can be applied to a power transmission device having different external shapes or having other additional functions, as long as the pressure member includes: a first pressure member capable of moving in a direction such that the first pressure member presses the drive-side clutch plate and the driven-side clutch plate against each other by receiving pressing force of the linkage member; a second pressure member capable of moving in a direction such that the second pressure member releases pressing contact force between the drive-side clutch plate and the driven-side clutch plate by receiving actuation force of the actuation member; and an anti-torque transmission cam that moves the second pressure member relative to the first pressure member to keep the drive-side clutch plate and the driven-side clutch plate pressed against each other when rotational force is input to the clutch member via the output member during movement of the weight member from the radially outer position to the radially inner position and movement of the first pressure member following the linkage member.

Claims

1. A power transmission device, the power transmission device comprising: A clutch assembly, the clutch assembly being housed in a clutch housing, the clutch housing rotating together with an input assembly that rotates by means of the driving force of a vehicle's engine, and a plurality of drive-side clutch plates attached to the clutch housing, a plurality of driven-side clutch plates alternately formed with the drive-side clutch plates attached to the clutch assembly, and the clutch assembly being connected to an output assembly capable of rotating the wheels of the vehicle. A pressure member is movable between a working position and a non-working position. In the working position, the pressure member presses the drive-side clutch plate and the driven-side clutch plate together to transmit the driving force of the engine to the wheels. In the non-working position, the pressure member releases the pressing contact force between the drive-side clutch plate and the driven-side clutch plate to stop transmitting the driving force of the engine to the wheels. The weight component is movable from a radially inner position to a radially outer position due to the centrifugal force generated as the clutch housing rotates; The linkage component, as the weight component moves from the radially inner position to the radially outer position, can move the pressure component from the non-working position to the working position; as well as An actuating member that can move the pressure member in a direction that releases the pressing contact force between the drive-side clutch plate and the driven-side clutch plate. The pressure component further includes: A first pressure member is capable of moving in a direction that causes the first pressure member to press the drive-side clutch plate and the driven-side clutch plate together by receiving the pressing force of the linkage member. A second pressure member, capable of moving in a direction that causes the second pressure member to release the pressing contact force between the drive-side clutch plate and the driven-side clutch plate by receiving the actuating force from the actuating member; and The anti-torque transmission cam, during the movement of the weight member from the radially outer position to the radially inner position and the movement of the first pressure member following the movement of the linkage member, when the rotational force is input to the clutch member via the output member, causes the second pressure member to move relative to the first pressure member, so as to keep the drive-side clutch plate and the driven-side clutch plate pressed against each other.

2. The power transmission device according to claim 1, wherein, The direction of movement of the second pressure member by means of the anti-torque transmission cam and the direction of movement of the second pressure member due to the actuation of the actuating member are opposite to each other.

3. The power transmission device according to claim 1 or 2, wherein, The anti-torque transmission cam is formed in the peripheral edge portion of each of the first pressure member and the second pressure member.

4. The power transmission device according to claim 1 or 2, wherein, The anti-torque transmission cam can move the second pressure member by pressing a sliding area on which the drive-side clutch plate and the driven-side clutch plate slide.

5. The power transmission device according to claim 1 or 2, wherein the power transmission device comprises: A release spring is provided to hold the pressure member in the non-working position. As the linkage member moves and the pressure member moves from the non-working position toward the working position, the release spring is compressed. The release spring is also capable of applying actuating force while allowing the linkage member and the pressure member to move until the drive-side clutch plate and the driven-side clutch plate reach an engaged state before pressing against each other. A clutch spring, which is compressed during the movement of the linkage member after the drive-side clutch plate and the driven-side clutch plate reach the engagement state, and is capable of applying a pressing contact force between the drive-side clutch plate and the driven-side clutch plate while allowing the linkage member to move; as well as A buffer member is inserted between the first pressure member and the second pressure member, and is compressed as the linkage member moves and the pressure member moves from the non-working position toward the working position, thereby enabling the linkage member to move while applying a driving force.

6. The power transmission device according to claim 5, wherein, The buffer member is a wave spring, which is composed of a C-shaped member having a cutout in a portion of its annular shape, and the anti-torque transmission cam is capable of supporting the outer peripheral surface of the wave spring.

7. The power transmission device according to claim 1 or 2, wherein the power transmission device includes a torque transmission portion formed in each of the first pressure member and the second pressure member, and is capable of transmitting rotational force already transmitted to the second pressure member to the first pressure member without using the anti-torque transmission cam.

8. A power transmission device, the power transmission device comprising: A clutch assembly, the clutch assembly being housed in a clutch housing, the clutch housing rotating together with an input assembly that rotates by means of the driving force of a vehicle's engine, and a plurality of drive-side clutch plates attached to the clutch housing, a plurality of driven-side clutch plates alternately formed with the drive-side clutch plates attached to the clutch assembly, and the clutch assembly being connected to an output assembly capable of rotating the wheels of the vehicle. A pressure member is movable between a working position and a non-working position. In the working position, the pressure member presses the drive-side clutch plate and the driven-side clutch plate together to transmit the driving force of the engine to the wheels. In the non-working position, the pressure member releases the pressing contact force between the drive-side clutch plate and the driven-side clutch plate to stop transmitting the driving force of the engine to the wheels. The weight component is movable from a radially inner position to a radially outer position due to the centrifugal force generated as the clutch housing rotates; The linkage component, as the weight component moves from the radially inner position to the radially outer position, can move the pressure component from the non-working position to the working position; as well as An actuating member that can move the pressure member in a direction that releases the pressing contact force between the drive-side clutch plate and the driven-side clutch plate. The pressure component further includes: A first pressure member is capable of moving in a direction that causes the first pressure member to press the drive-side clutch plate and the driven-side clutch plate together by receiving the pressing force of the linkage member. A second pressure member, capable of moving in a direction that causes the second pressure member to release the pressing contact force between the drive-side clutch plate and the driven-side clutch plate by receiving the actuating force from the actuating member; and The anti-torque transmission cam, when rotational force is input to the clutch member via the output member and the first pressure member moves with the linkage member in a direction that releases the pressing contact force between the drive-side clutch plate and the driven-side clutch plate, causes the second pressure member to move relative to the first pressure member in a direction that presses the drive-side clutch plate and the driven-side clutch plate against each other, so as to keep the drive-side clutch plate and the driven-side clutch plate pressed against each other.

Images