Power transmission device

Abstract

The present invention provides a power transmission device capable of improving operability by suppressing suddenness during power transmission. The power transmission device comprises: a linkage member (9) that can move a pressure member (5) from an inoperable position to an operable position; a release spring (m) that can apply a biasing force while allowing the linkage member and the pressure member to move until the driving side clutch plate (6) and the driven side clutch plate (7) reach an engaged state before being pressed; and a clutch spring (11) that contracts during the process of the linkage member moving to further move the pressure member after the driving side clutch plate and the driven side clutch plate reach the engaged state, and can apply a pressing force to the driving side clutch plate and the driven side clutch plate while allowing the linkage member and the pressure member to move. The clutch spring has a set load that is set to be smaller than the maximum load of the release spring.

Description

[0001] This application is a divisional application of the original invention patent application with application number 201980079472.1 (PCT application number: PCT / JP2019 / 047408, application date: December 4, 2019, invention name: power transmission device). Technical Field

[0002] The present invention relates to a power transmission device capable of appropriately transmitting or stopping the transmission of rotational power of an input member to an output member. Background Art

[0003] Typically, a motorcycle includes a power transmission device for appropriately transmitting or stopping the engine's driving force to the transmission and drive wheels. The power transmission device includes an input member coupled to the engine; an output member coupled to the transmission and drive wheels; 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 to stop transmitting power by moving the pressure member away from the clutch member to release the pressing force between the driving-side clutch plate and the driven-side clutch plate.

[0004] In a conventional power transmission device, such as that disclosed in Patent Document 1, a power transmission device including a weight member is proposed. The weight member can be moved from a radially inner position to a radially outer position in a groove portion due to centrifugal force generated by the rotation of the clutch housing, thereby pressing the driving-side clutch plate and the driven-side clutch plate against each other. In conventional power transmission devices, since the clutch housing rotates as the engine is driven, centrifugal force is applied to the weight member by pressing the driving-side clutch plate and the driven-side clutch plate against each other, thereby transmitting the engine's driving force to the wheels.

[0005] The existing power transmission device also includes: a release spring, which is compressed when the linkage member moves and the pressure member moves from the non-working position toward the working position, and the release spring can apply an urging force while allowing the linkage member and the pressure member to move until the driving side clutch plate and the driven side clutch plate reach an engaged state before being pressed against each other; and a clutch spring, which is compressed during the movement of the linkage member after the driving side clutch plate and the driven side clutch plate have reached an engaged state, and the clutch spring can apply a pressing force between the driving side clutch plate and the driven side clutch plate while allowing the linkage member to move.

[0006] Reference List

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-155884 Summary of the Invention

[0009] Technical issues

[0010] However, the conventional power transmission device has the following problems.

[0011] If the load (maximum load) at which the spring is released has reached the end of compression (see Figure 34 If the difference between the load (P1 in the figure) and the load (set load) at the start of compression of the clutch spring (see P2 in the figure) is large, in the process of the linkage member moving and the pressure member moving from the non-working position toward the working position as the engine speed increases, after the compression of the release spring has been completed and before the compression of the clutch spring begins, a dead zone appears that stops the movement of the linkage member (stops when maintaining the movement amount α1 in the figure).

[0012] Then, when the engine speed increases further and the pressing load applied to the linkage member reaches the set load of the clutch spring (at time P2 in the figure), the clutch spring begins to compress, so the linkage member begins to move again and passes through the dead band. However, because the clutch plates are pressed against each other and power is transmitted after having passed the dead band, a sense of surprise occurs when power is transmitted, which may affect operability.

[0013] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a power transmission device that can suppress a sense of surprise during power transmission and improve operability.

[0014] Solution to the problem

[0015] According to the invention described in the first aspect, a power transmission device includes: a clutch housing that rotates together with an input member, the input member being rotated by the driving force of a vehicle's engine, and a plurality of driving-side clutch plates being attached to the clutch housing; a clutch member, a plurality of driven-side clutch plates formed alternately with the plurality of driving-side clutch plates of the clutch housing being attached to the clutch member, and the clutch member being connected to an output member capable of rotating the wheels of the vehicle; a pressure member that can move between an operating position and an inoperative position, in which the pressure member presses the plurality of driving-side clutch plates and the plurality of driven-side clutch plates against each other so as to be able to transmit the driving force of the engine to the wheels, and in which the pressure member releases the pressing force between the plurality of driving-side clutch plates and the plurality of driven-side clutch plates so as to be able to stop transmitting the driving force of the engine to the wheels; a weight member that is provided in a groove portion extending in a radial direction of the clutch housing, and the weight member is generated due to the pressure generated when the clutch housing rotates. a linkage member capable of moving from a radially inner position to a radially outer position in the groove portion due to centrifugal force; a linkage member capable of moving the pressure member from the non-operating position to the operating position when the weight member moves from the radially inner position to the radially outer position; a release spring capable of holding the pressure member in the non-operating position, the release spring being compressed when the linkage member moves and the pressure member moves from the non-operating position toward the operating position, and capable of applying an urging force while allowing the linkage member and the pressure member to move until the plurality of driving-side clutch plates and the plurality of driven-side clutch plates reach an engaged state before the plurality of driving-side clutch plates and the plurality of driven-side clutch plates are pressed against each other; and a clutch spring capable of being compressed during movement of the linkage member after the plurality of driving-side clutch plates and the plurality of driven-side clutch plates have reached the engaged state, and capable of applying a pressing force between the plurality of driving-side clutch plates and the plurality of driven-side clutch plates while allowing the linkage member to move. A set load of the clutch spring is set to be smaller than a maximum load of the release spring.

[0016] According to the invention described in the second aspect, the power transmission device described in the first aspect includes a buffer member, which can apply a urging force by being compressed during the movement of the linkage member and the movement of the pressure member from the non-working position toward the working position, while allowing the linkage member and the pressure member to move.

[0017] According to the invention described in claim 3, in the power transmission device described in claim 2, the buffer member is formed of a spring having a set load such that the spring is compressed before the clutch spring starts to be compressed.

[0018] Advantageous Effects of the Invention

[0019] Through the invention described in the first aspect, the occurrence of dead zones can be avoided and operability can be improved by suppressing the unexpected feeling during power transmission, because the set load of the clutch spring is set to be smaller than the maximum load of the release spring, so the compression of the release spring and the compression of the clutch spring are continuously performed and the linkage member moves continuously.

[0020] Through the invention described in the second aspect, when the buffer member or the clutch spring is continuously compressed during the compression process of the release spring, the dead zone can be avoided, and the sense of surprise during power transmission can be further suppressed, and the operability can be improved because the power transmission device includes a buffer member, which is able to apply a urging force by being compressed during the movement of the linkage member and the movement of the pressure member from the non-working position to the working position, while allowing the linkage member and the pressure member to move.

[0021] According to the invention described in claim 3, the unexpected feeling during power transmission can be reliably suppressed because the buffer member is formed of a spring having a set load that causes the spring to be compressed before the clutch spring starts to be compressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [ Figure 1 ] is an external view of a power transmission device according to an embodiment of the present invention.

[0023] [ Figure 2 ] is a longitudinal sectional view illustrating the internal structure of the power transmission device.

[0024] [ Figure 3 ] is a schematic diagram of the driving side clutch plate, driven side clutch plate, reverse torque transmission cam, etc. of the power transmission device.

[0025] [ Figure 4 ] is a three-dimensional view of the housing portion of the clutch housing of the power transmission device.

[0026] [ Figure 5 ] is a three-dimensional view of the cover portion of the clutch housing of the power transmission device.

[0027] [ Figure 6 ] is a three-side view of the first clutch component of the power transmission device.

[0028] [ Figure 7] is a three-side view of the second clutch component of the power transmission device.

[0029] [ Figure 8 ] is a three-side view of the pressure component of the power transmission device.

[0030] [ Figure 9 ] is a perspective view illustrating a first clutch member, a second clutch member, a pressure member, and a bearing retaining member of the power transmission device before assembly.

[0031] [ Figure 10 ] is a perspective view illustrating a first clutch member, a second clutch member, a pressure member, and a bearing retaining member of the power transmission device before assembly.

[0032] [ Figure 11 ] is a stereoscopic view illustrating the first clutch member, the second clutch member, the pressure member and the bearing retaining member of the assembled power transmission device.

[0033] [ Figure 12 ] is a three-side view of the bearing retaining component of the power transmission device.

[0034] [ Figure 13 ] is a schematic diagram illustrating the function of the pressure-contact assist cam of the power transmission device.

[0035] [ Figure 14 ] is a schematic diagram illustrating the function of the reverse torque limiter cam of the power transmission device.

[0036] [ Figure 15 ] is a plan view of the first clutch member and the second clutch member of the power transmission device assembled together, illustrating a state in which one side surface of the protrusion and the first contact surface (torque transmission part) are in contact with each other.

[0037] [ Figure 16 ] is a plan view of the first clutch member and the second clutch member of the power transmission device assembled together, illustrating a state in which the other side surface of the protrusion and the second contact surface (movement limiting portion) are in contact with each other.

[0038] [ Figure 17 ] is a schematic diagram illustrating the function of the reverse torque transmission cam of the power transmission device in a state before the reverse torque transmission cam starts to operate.

[0039] [ Figure 18 ] is a schematic diagram illustrating the function of the reverse torque transmission cam of the power transmission device in a state after the reverse torque transmission cam has started operating.

[0040] [ Figure 19] is a schematic diagram illustrating a state in which a buffer member of a power transmission device according to another embodiment of the present invention is accommodated in an accommodating recess.

[0041] [ Figure 20 ] is a schematic diagram illustrating a state in which a release spring of the power transmission device applies an urging force to both the bearing holding member and the pressure member.

[0042] [ Figure 21 ] is a three-side view of the release spring of the power transmission device.

[0043] [ Figure 22 ] is a graph showing the movement amount and pressing load of the linkage member of the power transmission device.

[0044] [ Figure 23 ] is a graph showing the movement amount and pressing load of the linkage member of the power transmission device according to another embodiment of the present invention.

[0045] [ Figure 24 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention.

[0046] [ Figure 25 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention.

[0047] [ Figure 26 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention.

[0048] [ Figure 27 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention (provided with a buffer member 12' and including a pull-type actuating member 10").

[0049] [ Figure 28 ] shows a plan view and a side view of a buffer member of a power transmission device.

[0050] [ Figure 29 ] is a three-dimensional view of the buffer component of the power transmission device.

[0051] [ Figure 30 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention (provided with a buffer member 12 and including a pull-type actuating member 10").

[0052] [ Figure 31 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention (a reverse torque transmission cam is provided at the outer edge of the first clutch member 4a).

[0053] [ Figure 32] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention (a reverse torque transmission cam is provided at the outer edge of the first clutch member 4a, and a buffer member composed of a conical disc spring is provided).

[0054] [ Figure 33 ] is a longitudinal sectional view of a power transmission device according to another embodiment of the present invention (a reverse torque transmission cam is provided at the outer edge of the first clutch member 4a, and a buffer member composed of a wave spring is provided).

[0055] [ Figure 34 ] is a graph showing the movement amount and pressing load of the linkage component of the existing power transmission device.

[0056] Reference Signs List

[0057] 1 Input gear (input component)

[0058] 2 Clutch housing

[0059] 2a Housing

[0060] 2b Cover

[0061] 3 Output shaft (output component)

[0062] 4a First clutch member

[0063] 4aa Inclined surface (crimp assist cam)

[0064] 4ab Inclined surface (reverse torque limiter cam)

[0065] 4ac flange surface

[0066] 4ad insertion hole

[0067] 4b Second clutch member

[0068] 4ba spline fitting part

[0069] 4bb pressing part

[0070] 4c Accommodating recess

[0071] 4d concavity

[0072] 4da Inner wall surface

[0073] 5 Pressure components

[0074] 5a Inclined surface (crimp assist cam)

[0075] 5b Inclined surface (reverse torque limiter cam)

[0076] 5c Flange surface

[0077] 6 Drive side clutch plate

[0078] 7 Driven side clutch plate

[0079] 8 Counterweight components

[0080] 9 Linkage components

[0081] 10 Actuating member

[0082] 11 Clutch spring

[0083] 12 Buffer member (conical disc spring)

[0084] 12' buffer member (wave spring)

[0085] 12'a incision

[0086] C Bearing retaining member

[0087] Ca open end

[0088] Cb Top

[0089] Cc connecting hole

[0090] K-slot

[0091] K1 cam surface

[0092] K2 wall surface

[0093] T-tab

[0094] T1 cam surface

[0095] T2 wall surface

[0096] F protrusion

[0097] G protrusion

[0098] G1 First contact surface

[0099] G2 Second contact surface

[0100] m Release spring

[0101] r Oil flow path DETAILED DESCRIPTION

[0102] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0103] The power transmission device according to the present embodiment is a device provided in a vehicle such as a motorcycle, and is used to appropriately transmit or stop the driving force of the engine to the transmission or toward the drive wheel side. Figures 1 to 12 As shown, the power transmission device mainly includes: a clutch housing 2, in which an input gear 1 (input member) is formed that is rotated by the driving force of the vehicle's engine; clutch members (a first clutch member 4a and a second clutch member 4b); a pressure member 5 attached to the clutch members (the first clutch member 4a and the second clutch member 4b). Figure 2 The right side of the clutch housing 2 is shown in FIG. 1 ; a plurality of driving-side clutch plates 6 ; a plurality of driven-side clutch plates 7 ; a weight member 8 composed of steel ball members that can move (roll) radially within the clutch housing 2 ; a linkage member 9 ; and an actuating member 10 that can be actuated manually or by an actuator (not shown). Symbol S in the figure denotes a spring damper, symbol B1 denotes a roller bearing, and symbols B2 and B3 denote thrust bearings, respectively.

[0104] When the driving force (rotational force) transmitted from the engine is input, the input gear 1 can rotate around the output shaft 3. The input gear 1 is connected to the clutch housing 2 via rivets R or the like. The clutch housing 2 includes a housing portion 2a and a cover portion 2b. The housing portion 2a is composed of a cylindrical member (in Figure 2 The right side of the clutch housing 2 is open and is connected to the input gear 1. The cover portion 2b is attached to close the opening of the housing portion 2a. Due to the driving force of the engine, the clutch housing 2 can rotate along with the rotation of the input gear 1.

[0105] like Figure 4 As shown, a plurality of cutouts 2aa are formed in the housing portion 2a of the clutch housing 2 so as to be arranged in the circumferential direction, and a plurality of drive-side clutch plates 6 are attached so as to fit into the cutouts 2aa. Each drive-side clutch plate 6 is composed of a substantially annular plate, is configured to be rotatable along with the rotation of the clutch housing 2, and is axially ( Figure 2 swipe left or right).

[0106] In addition, if Figure 5 As shown, a plurality of grooves 2ba extending in the radial direction of the cover portion 2b are formed in the bottom surface of the cover portion 2b of the clutch housing 2. A weight member 8 is provided in each of the plurality of grooves 2ba. When the clutch housing 2 is stopped (engine stopped or idling) and the clutch housing 2 is rotating at a low speed, the weight member 8 is located in a radially inner position ( Figure 2 When the clutch housing 2 rotates at a high speed, the weight member 8 is located at a radially outer position.

[0107] A plurality of driven-side clutch plates 7, formed alternately with the driving-side clutch plates 6 of the clutch housing 2, are attached to the clutch members (first clutch member 4a and second clutch member 4b). The clutch members are coupled to the output shaft 3 (output member) capable of rotating the vehicle's wheels. The clutch members are constructed by assembling the first clutch member 4a and the second clutch member 4b.

[0108] like Figure 6 As shown, the first clutch member 4a is composed of a disc-shaped member having a flange surface 4ac formed along the peripheral portion of the disc-shaped member. The first clutch member 4a is configured so that the output shaft 3 is inserted into an insertion hole 4ad formed at the center thereof (see FIG. Figure 2 and Figure 6 ), and the first clutch member 4a and the output shaft 3 are coupled to each other in the rotational direction because the gears respectively formed therein are engaged with each other. Figure 6 、 Figure 9 and Figure 10 As shown, in the first clutch member 4a, an inclined surface 4aa constituting a pressure-contact assist cam and an inclined surface 4ab constituting a reverse torque limiter cam are formed.

[0109] like Figure 7 As shown, the second clutch member 4b is composed of an annular member and is configured so that the driven side clutch plate 7 is attached to the spline fitting portion 4ba formed in the outer peripheral surface thereof by spline fitting (see FIG. Figure 2 and Figure 7 ).like Figures 9 to 11 As shown, the pressure member 5 is assembled with the clutch members (the first clutch member 4a and the second clutch member 4b). A plurality of driving side clutch plates 6 and driven side clutch plates 7 in an alternately stacked state are attached to the flange surface 5c of the pressure member 5 (see FIG. Figure 2 and Figure 8 ) and the flange surface 4ac of the first clutch member 4a (see Figure 2 and Figure 6 )between.

[0110] like Figure 8 As shown, the pressure member 5 is composed of a disc-shaped member, and a flange surface 5c is formed along its peripheral portion. The pressure member 5 can be in the working position and the non-working position (see Figure 2 ) in the working position, the pressure member 5 presses the driving side clutch plate 6 and the driven side clutch plate 7 against each other so as to transmit the driving force of the engine to the wheels, and in the non-working position, the pressure member 5 releases the pressing force between the driving side clutch plate 6 and the driven side clutch plate 7 so as to stop transmitting the driving force of the engine to the wheels.

[0111] More specifically, if Figure 7 、 Figure 9 and Figure 10 As shown, the splined engagement portion 4ba formed in the second clutch member 4b has a protrusion / recess shape integrally formed along substantially the entire circumference of the outer peripheral surface of the second clutch member 4b. When the driven-side clutch plate 7 is fitted into the groove of the splined engagement portion 4ba, the driven-side clutch plate 7 is restricted from movement in the rotational direction while being allowed to move in the axial direction relative to the second clutch member 4b, and the driven-side clutch plate 7 can rotate together with the second clutch member 4b.

[0112] The driven side clutch plates 7 and the driving side clutch plates 6 are stacked alternately, and the clutch plates 6 and 7 can be pressed against each other, or the pressing force between them can be released. That is, both the clutch plates 6 and 7 are allowed to slide in the axial direction of the second clutch member 4b. Figure 2 When the pressure member 5 moves leftward in the middle and its flange surface 5c moves toward the flange surface 4ac of the first clutch member 4a, the clutch plates 6 and 7 are pressed against each other to transmit the rotational force of the clutch housing 2 to the output shaft 3 via the second clutch member 4b and the first clutch member 4a. Figure 2 When the clutch housing 2 moves to the right and its flange surface 5c and the flange surface 4ac of the first clutch member 4a become separated from each other, the pressing force between the clutch plates 6 and 7 is released, and the first clutch member 4a and the second clutch member 4b stop following the rotation of the clutch housing 2 and stop transmitting the rotational force to the output shaft 3.

[0113] When the driving-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other, the rotational force (engine driving force) input to the clutch housing 2 is transmitted to the wheels via the output shaft 3 (output member). When the pressure contact between the driving-side clutch plates 6 and the driven-side clutch plates 7 is released, the rotational force (engine driving force) input to the clutch housing 2 is prevented from being transmitted to the output shaft 3 (output member).

[0114] In addition, if Figure 6 、 Figure 8 、 Figure 9 and Figure 10 As shown, in the present embodiment, inclined surfaces 4aa and 4ab are formed in the first clutch member 4a, and inclined surfaces 5a and 5b facing the inclined surfaces 4aa and 4ab are formed in the pressure member 5. That is, the inclined surface 4aa and the inclined surface 5a are in contact with each other to constitute a pressure assist cam, and the inclined surface 4ab and the inclined surface 5b are in contact with each other to constitute a reverse torque limiter cam.

[0115] like Figure 13As shown in FIG. 1 , when the engine speed increases and the rotational force input to the input gear 1 and the clutch housing 2 becomes capable of being transmitted to the output shaft 3 via the first clutch member 4a and the second clutch member 4b, a rotational force in direction a is applied to the pressure member 5 (the weight member 8 is in a radially outer position). Therefore, due to the action of the pressure-contact auxiliary cam, a force in direction c in the figure is generated in the pressure member 5. As a result, the flange surface 5c of the pressure member 5 is rotated in a direction further toward the flange surface 4ac of the first clutch member 4a ( FIG. 1 ). Figure 2 The driving side clutch plate 6 and the driven side clutch plate 7 are pressed together by the pressure member 5, and the pressure member 5 increases the pressing force between the driving side clutch plate 6 and the driven side clutch plate 7.

[0116] On the other hand, when the vehicle is running, when the speed of the output shaft 3 exceeds the speed of the input gear 1 and the clutch housing 2 and a Figure 14 When reverse torque occurs in direction b, the reverse torque limiter cam causes the pressure member 5 to move in direction d in the figure, releasing the pressure between the driving clutch plate 6 and the driven clutch plate 7. This prevents damage to the power transmission device and the power source (engine side) caused by reverse torque.

[0117] The weight member 8 is provided in a groove portion 2ba extending in the radial direction of the clutch housing 2 (in this embodiment, the cover portion 2b). The weight member 8 is displaced from a radially inner position (see FIG. 1 ) in the groove portion 2ba by the centrifugal force generated when the clutch housing 2 rotates. Figure 2 ) moves to a radially outward position to press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other. Specifically, the rolling surface (bottom surface) of the groove portion 2ba, in which the weight member 8 rolls, has an upward slope from a radially inward position toward a radially outward position. When the clutch housing 2 is stopped, the weight member 8 is held in the radially inward position due to the urging force of the release spring m. As the clutch housing 2 rotates, centrifugal force is applied to the weight member 8, and when the clutch housing 2 reaches a predetermined rotational speed, the weight member 8 moves along the upward slope to a radially outward position.

[0118] The linkage member 9 is composed of an annular member provided in the clutch housing 2 (cover 2b). The linkage member 9 is engaged with a groove formed in the inner peripheral surface of the cover 2b and can rotate together with the clutch housing 2 and can rotate when the clutch housing 2 is in the clutch housing 2. Figure 2 When the weight member 8 moves from the radially inner position to the radially outer position, the linkage member 9 overcomes the urging force of the clutch spring 11 and the release spring m. Figure 2 The pressure member 5 can be moved to the left in the middle, and the pressure member 5 can be pressed to move the pressure member 5 from the non-operating position to the operating position.

[0119] The actuating member 10 can be operated by hand or by an actuator (see Figure 2) operating member, and the pressing force of the pressure member 5 between the driving side clutch plate 6 and the driven side clutch plate 7 can be released ( Figure 2 When a shift operation is performed, for example, by operating a clutch pedal, a clutch lever, etc. of a vehicle or by the operation of an actuator, the actuating member 10 moves in the direction of the right. Figure 2 The actuating member 10 moves rightward to contact the pressure member 5 via the bearing retaining member C and moves the pressure member 5 from the operating position to the non-operating position. Therefore, by releasing the pressing force between the driving side clutch plate 6 and the driven side clutch plate 7, the actuating member 10 can disengage the clutch (stop transmitting power).

[0120] like Figure 2 As shown, the bearing holding member C is coupled to the actuating member 10 and holds the bearing B1 interposed between the actuating member 10 and the pressure member 5. Figure 12 As shown, the bearing retaining member C is composed of a cylindrical member with one end open, and includes an open end portion Ca and a top portion Cb located opposite the open end portion Ca. The bearing B1 according to this embodiment is attached to the top portion Cb side of the bearing retaining member C, and the cylindrical portion extends from the increased diameter portion toward the open end portion Ca. Furthermore, although a ball bearing is used as the bearing B1 according to this embodiment, another bearing such as a needle roller bearing may be used.

[0121] In addition, if Figure 2 and Figure 20 As shown, the open end Ca of the bearing retaining member C according to this embodiment is fitted and attached to the recess 4d formed in the clutch member (first clutch member 4a), and is assembled with the inner peripheral wall surface 4da of the recess 4d through a socket-and-socket joint (fitting joint). The recess 4d is formed as a circular depression with a shape similar to the outer shape of the open end Ca and having substantially the same dimensions as the outer shape of the open end Ca (strictly speaking, the dimensions are slightly larger than the open end Ca). By fitting the bearing retaining member C into the recess 4d, positioning and centering are performed relative to the power transmission device.

[0122] In the shifting operation, when the actuating member 10 is moved by, for example, operating a clutch pedal, a clutch lever, etc. of the vehicle or by working of an actuator, Figure 2 When the clutch plate 6 and the driven clutch plate 7 move to the right, the bearing retaining member C moves together and contacts the pressure member 5 to move the pressure member 5 from the operating position to the non-operating position. As a result, the clutch is disengaged (power transmission is stopped) by releasing the pressing force between the driving side clutch plate 6 and the driven side clutch plate 7.

[0123] The release spring m can hold the pressure member 5 in the non-operating position and is compressed when the linkage member 9 moves and the pressure member 5 moves from the non-operating position to the operating position. The release spring m can apply an urging force while allowing the linkage member 9 and the pressure member 5 to move until the driving side clutch plate 6 and the driven side clutch plate 7 reach an 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 is performed due to the pressing contact) before being pressed against each other.

[0124] In addition, if Figure 21 As shown, the release spring m according to this embodiment is composed of a conical disc spring that can generate an urging force due to the displacement between the middle portion ma and the peripheral portion mb. Figure 2 and Figure 20 As shown, the middle portion ma is attached to the top Cb of the bearing holding member C, and the peripheral portion mb is attached to the pressure member 5. The pressure member 5 has a protrusion 5d protruding in an annular shape, and the peripheral portion mb of the release spring m is engaged with the annular member g (for example, a circlip, etc.) attached to the protrusion 5d and attached to the annular member g. Therefore, the release spring m according to this embodiment is attached to both the bearing holding member C and the pressure member 5, and the urging force (at Figure 20 An urging force (an urging force in the orientation indicated by symbol a2 in the figure) is applied to the pressure member 5, and an urging force (an urging force in the orientation indicated by symbol a1 in the figure) can be applied to the bearing holding member C to transmit the urging force to the actuating member 10.

[0125] The clutch spring 11 is composed of a coil spring interposed between the linkage member 9 and the pressure member 5. When the linkage member 9 moves, the clutch spring 11 presses the pressure member 5, causing the pressure member 5 to move in a direction that presses the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other. Furthermore, when the actuating member 10 operates, the clutch spring 11 absorbs the pressing force applied by the pressure member 5 to the linkage member 9.

[0126] According to the present embodiment, the clutch spring 11 is compressed during the movement of the linkage member 9 and can apply a pressing force between the driving side clutch plate 6 and the driven side clutch plate 7, while allowing the linkage member 9 to move before the driving side clutch plate 6 and the driven side clutch plate 7 reach the above-mentioned engagement state.

[0127] That is, when the weight member 8 moves from the radially inner position to the radially outer position and the linkage member 9 is pressed by the weight member 8 when the clutch housing 2 rotates, the pressing force is transmitted to the pressure member 5 via the clutch spring 11, causing the pressure member 5 to rotate. Figure 28. When the actuating member 10 is actuated in this state, although the pressure member 5 moves rightward in the figure due to the pressing force of the actuating 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.

[0128] Here, the power transmission device according to the present embodiment includes a reverse torque transmission cam (cam surfaces K1 and T1) that can move the second clutch member 4b to press the driving side clutch plate 6 and the driven side clutch plate 7 against each other when a rotational force is input to the first clutch member 4a via the output shaft 3 (output member). Figure 6 、 Figure 7 、 Figure 9 and Figure 10 As shown, the reverse torque transmission cam is composed of cam surfaces ( K1 , T1 ) integrally formed in the mating surfaces (mating surfaces when engaged) of the first clutch member 4 a and the second clutch member 4 b , respectively.

[0129] like Figure 6 and Figure 9 As shown, the cam surface K1 is composed of multiple inclined surfaces formed along the entire circumference of the radially inner side of the flange surface 4ac of the first clutch member 4a (the mating surface with the second clutch member 4b). The cam surface K1 is formed in one end surface of each of the multiple grooves K formed annularly along the peripheral portion of the first clutch member 4a. In other words, the multiple grooves K are formed in the first clutch member 4a so as to be arranged in its circumferential direction, and one end surface of each groove K is an inclined surface that constitutes the cam surface K1 of the reverse torque transmission cam. The other end surface of each groove K is a wall surface K2 extending in the axial direction of the first clutch member 4a.

[0130] like Figure 7 and Figure 10 As shown, the cam surface T1 is composed of multiple inclined surfaces formed along the entire circumference of the bottom surface of the second clutch member 4b (the mating surface with the first clutch member 4a). The cam surface T1 is formed on one end surface of each of the multiple protrusions T formed annularly along the bottom surface of the second clutch member 4b. In other words, the multiple protrusions T are formed in the second clutch member 4b so as to be arranged in its circumferential direction, and one end surface of each protrusion T is an inclined surface that constitutes the cam surface T1 of the reverse torque transmission cam. The other end surface of each protrusion T is a wall surface T2 extending in the axial direction of the second clutch member 4b.

[0131] like Figure 17As shown, when the protrusion T is fitted into the groove portion K to couple the first clutch member 4a and the second clutch member 4b to each other, the cam surface K1 and the cam surface T1 face each other to constitute a reverse torque transmission cam, and the wall surface K2 and the wall surface T2 face each other with a predetermined distance therebetween. When a rotational force is input to the first clutch member 4a via the output shaft 3, since the first clutch member 4a rotates relative to the second clutch member 4b, as shown in FIG. Figure 18 As shown, due to the cam action of the cam surface K1 and the cam surface T1, the second clutch member 4b is relative to the first clutch member 4a. Figure 2 and Figure 18 Move right.

[0132] like Figure 7 As shown, the pressing portion 4bb is formed in the second clutch member 4b on the extension line of the spline fitting portion 4ba. Figure 2 When the pressure member 5 moves rightward in the middle, the pressing portion 4bb presses the driven-side clutch plate 7 on the far left in the figure in the same direction. The driven-side clutch plate 7 is one of the driving-side clutch plate 6 and the driven-side clutch plate 7 attached in a stacked state. Therefore, even when the pressure member 5 is in the non-operating position, the driving-side clutch plate 6 and the driven-side clutch plate 7 can be pressed against each other, and when rotational force is input from the output shaft 3 (output member), the rotational force can be transmitted to the engine side to apply engine braking.

[0133] In particular, the reverse torque transmission cam according to the present embodiment can cause the second clutch member 4b to move in a direction toward the linkage member 9 ( Figure 2 In other words, when the reverse torque transmission cam starts to work and causes the second clutch member 4b to move upward (rightward) to maintain contact between the linkage member 9 and the weight member 8. Figure 2 When the clutch plate 6 and the driven clutch plate 7 are moved to the right, the reverse torque transmission cam presses the driving side clutch plate 6 and the driven side clutch plate 7 against each other and presses the pressure member 5 in the same direction. Therefore, the pressing force is transmitted to the linkage member 9 via the clutch spring 11, and the contact between the linkage member 9 and the counterweight member 8 is maintained.

[0134] If the link member 9 and the weight member 8 are separated from each other when the reverse torque transmission cam is in operation, even when the weight member 8 subsequently moves between the radially inner position and the radially outer position as the clutch housing 2 rotates, the link member 9 cannot follow this movement. In contrast, in the present embodiment, contact between the link member 9 and the weight member 8 is maintained even when the reverse torque transmission cam is in operation, so the link member 9 can stably follow the movement of the weight member 8.

[0135] Furthermore, the multiple cam surfaces K1 and T1 of the reverse torque transfer cam according to this embodiment are formed along the annular shape of the driven-side clutch plate 7 attached to the second clutch member 4b. Specifically, the cam surfaces K1 and T1 are formed along the projected shape (annular shape) of the driven-side clutch plate 7. When the reverse torque transfer cam is in operation, the driven-side clutch plate 7 is pressed by the pressing portion 4bb. Therefore, due to the cam action of the reverse torque transfer cam, the pressing portion 4bb can apply a substantially uniform pressing force to the driven-side clutch plate 7, and can more effectively press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other.

[0136] Furthermore, the reverse torque transmission cam according to this embodiment (the cam composed of the cam surface K1 and the cam surface T1) can start operating before the reverse torque limiter cam (the cam composed of the inclined surface 4ab and the inclined surface 5b) starts operating. That is, the gap between the cam surface K1 and the cam surface T1 (the size of the gap) is smaller than the gap between the inclined surface 4ab and the inclined surface 5b (the size of the gap), and the reverse torque transmission cam can start operating before the reverse torque limiter cam starts operating.

[0137] In addition, the power transmission device according to the present embodiment includes: a torque transmission portion, which is formed in each of the first clutch member 4a and the second clutch member 4b, and can transmit the rotational force that has been transmitted to the second clutch member 4b to the first clutch member 4a without using the reverse torque transmission cam (cam surface K1 and cam surface T1); and a movement amount limiting portion, which is formed in each of the first clutch member 4a and the second clutch member 4b, and limits the movement amount of the second clutch member 4b due to the reverse torque transmission cam (cam surface K1 and cam surface T1).

[0138] That is, Figure 6 and Figure 9 As shown, a plurality of (three in the present embodiment) protrusions F are integrally formed in the first clutch member 4a so as to be arranged at regular intervals in the circumferential direction. Figure 7 and Figure 9 As shown, an inwardly extending protrusion G is integrally formed in the second clutch member 4b. Figure 15 and Figure 16 As shown, when the first clutch member 4a and the second clutch member 4b are assembled together, one protrusion F is placed between the two protrusions G, one side surface F1 of the protrusion F and the contact surface of one of the protrusions G (first contact surface G1) face each other, and the other side surface F2 of the protrusion F and the contact surface of the other protrusion G (second contact surface G2) face each other.

[0139] One side surface F1 of the protrusion F formed in the first clutch member 4a and the first contact surface G1 of the protrusion G formed in the second clutch member 4b constitute the torque transmission portion according to the present embodiment. Figure 15 As shown, when the pressure member 5 moves to the working position to press the driving side clutch plate 6 and the driven side clutch plate 7 against each other and engage the clutch (transmit the driving force), the wall surface K2 of the groove portion K and the wall surface T2 of the protrusion T of the reverse torque transmission cam are kept in a separated state (see FIG. Figure 17 ), one side surface F1 of the protrusion F and the first contact surface G1 of the protrusion G are in contact with each other, and the rotational force of the second clutch member 4b can be received and transmitted to the first clutch member 4a.

[0140] The other side surface F2 of the protrusion F formed in the first clutch member 4a and the second contact surface G2 of the other protrusion G formed in the second clutch member 4b constitute the movement amount limiting portion according to the present embodiment. That is, when the rotational force is input to the first clutch member 4a via the output shaft 3, the first clutch member 4a and the second clutch member 4b rotate relative to each other. Therefore, the second clutch member 4b moves due to the cam action of the cam surface K1 of the groove portion K and the cam surface T1 of the protrusion T of the reverse torque transmission cam (see Figure 18 ). When the movement amount reaches the set value, Figure 16 As shown, the other side surface F2 of the protrusion F and the second contact surface G2 of the protrusion G are in contact with each other, and the rotation of the second clutch member 4b relative to the first clutch member 4a is restricted, so when the reverse torque transfer cam works, the movement amount of the second clutch member 4b can be limited.

[0141] In this embodiment, the protrusion F is formed in the first clutch member 4a, and the protrusion G is formed in the second clutch member 4b. Alternatively, the protrusion G can be formed in the first clutch member 4a, and the protrusion F can be formed in the second clutch member 4b. In this case, one side surface F1 of the protrusion F formed in the second clutch member 4b and the first contact surface G1 of one protrusion G formed in the first clutch member 4a constitute the torque transmission portion according to this embodiment. The other side surface F2 of the protrusion F formed in the second clutch member 4b and the second contact surface G2 of the other protrusion G formed in the first clutch member 4a constitute the movement limiter according to this embodiment.

[0142] Next, the function of the reverse torque transmission cam in the present embodiment will be described.

[0143] like Figure 2As shown, when the engine is stopped or idling, the engine's driving force is not transmitted to the input gear 1, or the rotational speed of the input gear 1 is low, so the weight member 8 is in the radially inner position and the pressure member 5 is in the non-operating position. At this time, when rotational force is input to the first clutch member 4a via the output shaft 3 (output member), the cam action of the reverse torque transmission cam causes the second clutch member 4b to move rightward in the figure, and the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other to transmit the rotational force to the engine side.

[0144] When the vehicle starts moving after having stopped or idling, the rotational speed of the input gear 1 changes from a low rotational speed to a high rotational speed (intermediate rotational speed range), the weight member 8 is located between the radially inner position and the radially outer position, and the pressure member 5 is located in the operating position. At this time, when rotational force is input to the first clutch member 4a via the output shaft 3 (output member), for example, when the accelerator pedal is released on a downhill slope, the cam action of the reverse torque transmission cam causes the second clutch member 4b to move rightward in the figure, and the driving side clutch plate 6 and the driven side clutch plate 7 are pressed against each other to transmit the rotational force to the engine side.

[0145] After the vehicle starts, when it accelerates and travels within the high-speed range, the rotational speed of the input gear 1 is high, so the weight member 8 is located in the radially outer position, and the pressure member 5 is located in the operating position. At this time, when rotational force is input to the first clutch member 4a via the output shaft 3 (output member) in response to a downshift or the like, the cam action of the reverse torque transmission cam causes the second clutch member 4b to move rightward in the figure, and the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other to transmit the rotational force to the engine side.

[0146] Here, in the power transmission device according to this embodiment, the set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring m. Therefore, when the engine speed increases and the weight member 8 moves from the radially inner position to the radially outer position, as the link member 9 is pressed and moved by the weight member 8, when the release spring m is compressed and exceeds the set load of the clutch spring 11, the clutch spring 11 begins to be compressed, thereby preventing the occurrence of a dead zone.

[0147] Next, the function of the power transmission device of the present embodiment will be described in comparison with a conventional power transmission device in which the set load of the clutch spring is set to be larger than the maximum load of the release spring.

[0148] First, refer to Figure 34The function of the existing power transmission device is described by a graph (a graph having a movement amount (mm) of the linkage member 9 along the horizontal axis and a pressing load (N) generated in the linkage member 9 along the vertical axis). Figure 34 In the curve diagram, P1 represents the pressing load of the linkage member 9 when the deformation (compression) of the release spring m is maximum (when the maximum load of the release spring m is reached), and P2 represents the pressing load of the linkage member 9 when the clutch spring 11 begins to deform (when the set load of the clutch spring 11 is reached).

[0149] In the process of increasing the engine speed and moving the counterweight member 8 from the radially inner position to the radially outer position to move the linkage member 9, the release spring m is deformed and the clutch spring 11 is not deformed (that is, the linkage member 9 and the pressure member 5 move together) until the movement amount of the linkage member 9 reaches α1, and, when the movement amount of the linkage member 9 reaches α1, although the pressing load (N) increases from P1 to P2, the linkage member 9 stops moving and becomes a dead zone.

[0150] When the pressing load (N) reaches P2 (the set load of the clutch spring 11) from this state, the clutch spring 11 begins to deform, and the pressing load (N) increases with the movement of the linkage member 9. Therefore, the linkage member 9 and the pressure member 5 stop until the pressing load (N) reaches P2 from P1, and after the pressing load (N) has reached P2, the clutch spring 11 begins to be compressed, the clutch plates (the driving side clutch plates 6 and the driven side clutch plates 7) are pressed against each other to transmit power, and therefore a sense of surprise is generated when power is transmitted.

[0151] On the contrary, in this embodiment, the set load P2 of the clutch spring 11 is set to be smaller than the maximum load P1 of the release spring m. Figure 22 As shown, during the movement of the linkage member 9, the release spring m is compressed and deformed. When the movement of the linkage member 9 reaches α2, the release spring m reaches the set load P2 of the clutch spring 11, and the clutch spring 11 begins to be compressed (deformed). Subsequently, when the movement of the linkage member 9 reaches α1, the release spring m reaches the maximum load P1. When the release spring m stops being further compressed (deformed), the clutch spring 11 is compressed and deformed, so that the linkage member 9 continues to move.

[0152] Specifically, according to the diagram, as the engine speed increases and the weight member 8 moves from the radially inner position to the radially outer position, thereby moving the linkage member 9, the release spring m is continuously compressed (deformed) until the movement of the linkage member 9 reaches α2. When the movement of the linkage member 9 reaches α2 and the pressing load (N) reaches the set load P2 of the clutch spring 11, the clutch spring 11 begins to deform along with the release spring m. Subsequently, when the movement of the linkage member 9 reaches α1, the release spring m reaches the maximum load P1 and stops deforming, while the clutch spring 11 continues to deform (become compressed), causing the linkage member 9 to continue to move.

[0153] Therefore, before the movement of the linkage member 9 reaches α1 (before the pressing load reaches P1), only the release spring m deforms until the movement of the linkage member 9 reaches α2. Both the release spring m and the clutch spring 11 deform until the movement of the linkage member 9 reaches α1, allowing the linkage member 9 to move continuously. When the movement of the linkage member 9 reaches α1 and the pressing load reaches the maximum load P1 of the release spring, the release spring m stops deforming, while the clutch spring 11 continues deforming, allowing the linkage member 9 to move continuously. Consequently, the existing dead zone can be reduced, and the weight member 8 and the linkage member 9 can move smoothly and continuously, thereby suppressing the shock during clutch engagement and the sense of surprise during power transmission.

[0154] This embodiment does not include a spring or the like between the first clutch member 4a and the second clutch member 4b. However, for example, a buffer member 12 may be provided between the first clutch member 4a and the second clutch member 4b. In this case, the buffer member 12 is interposed between the first clutch member 4a and the second clutch member 4b and can be compressed (spring-deformed) during movement of the linkage member 9 and movement of the pressure member 5 from the non-operating position to the operating position, thereby applying an urging force while allowing movement of the linkage member 9 and the pressure member 5.

[0155] More specifically, the buffer member 12 is composed of a spring having a set load that causes the spring to be compressed before the clutch spring 11 starts to be compressed. Figure 2 、 Figure 3 and Figure 19 As shown, the buffer member 12 is assembled by being accommodated in an accommodating recess 4c formed in surfaces of the first clutch member 4a and the second clutch member 4b facing each other (specifically, a surface of the first clutch member 4a facing the second clutch member 4b).

[0156] The accommodating recess 4c is constituted by an annular groove, and the buffer member 12 is constituted by a conical disc spring having an annular shape conforming to the shape of the groove. Figure 19As shown, the accommodating recess 4c is composed of a groove having a radially inner wall surface 4ca and a radially outer wall surface 4cb; and the buffer member 12 composed of an annular spring conforms to the shape of the groove and is fitted into the accommodating recess 4c.

[0157] The reverse torque transmission cams according to the present embodiment are formed in a plurality of annular shapes in the surfaces of the first clutch member 4a and the second clutch member 4b facing each other. Figure 6 As shown, the accommodating recess 4 c is formed in a concentric circular shape at a position adjacent to the counter torque transmission cam (in the present embodiment, radially inside the position where the counter torque transmission cam is formed).

[0158] The buffer member 12 is set to a load (P3) so that the buffer member 12 is compressed before the clutch spring 11 starts to be compressed. Figure 23 As shown, before the movement of the linkage member 9 reaches α1 (before the pressing load reaches P1), only the release spring m deforms until the movement of the linkage member 9 reaches α2. The release spring m and clutch spring 11 both deform until the movement of the linkage member 9 reaches α3. Subsequently, the release spring m, clutch spring 11, and buffer member 12 all deform until the movement of the linkage member 9 reaches α1, allowing the linkage member 9 to move continuously. When the movement of the linkage member 9 reaches α1 and the pressing load reaches the maximum load P1 of the release spring (the maximum load of the buffer member 12), the release spring m and buffer member 12 stop deforming, while the clutch spring 11 continues to deform, allowing the linkage member 9 to move continuously. Consequently, in this case as well, the existing dead zone can be reduced, allowing the weight member 8 and the linkage member 9 to move smoothly and continuously, thereby suppressing the shock during clutch engagement and the sense of surprise during power transmission.

[0159] In the case where the buffer member 12 is provided as described above, the accommodating recess 4c is formed in a concentric circular shape at a position radially inside the position of the reverse torque transmission cam. However, the accommodating recess 4c may be formed in a concentric circular shape at a position radially outside the position of the reverse torque transmission cam. In this case, as Figure 24 As shown, the buffer member 12 may be configured to apply an urging force to a portion (disc pack) where the driving side clutch plates 6 and the driven side clutch plates 7 are stacked in a direction in which the driving side clutch plates 6 and the driven side clutch plates 7 are pressed against each other.

[0160] In this embodiment, since the set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring m, the compression of the release spring m and the compression of the clutch spring 11 are continuously performed, and the linkage member 9 moves continuously, it is possible to avoid the occurrence of a dead zone and improve operability by suppressing the unexpected feeling during power transmission.

[0161] In the case where the power transmission device includes a buffer member 12, wherein the buffer member 12 can be compressed during the movement of the linkage member 9 and the movement of the pressure member 5 from the non-operating position to the operating position, thereby applying an urging force while allowing the linkage member 9 and the pressure member 5 to move. When the buffer member 12 or the clutch spring 11 is compressed during the compression process of the release spring m, a dead zone can be avoided, and the sense of surprise during power transmission can be further suppressed, thereby improving operability. In addition, when the buffer member 12 is provided, since the buffer member 12 is composed of a spring with a set load that causes the spring to be compressed before the clutch spring 11 begins to be compressed, the sense of surprise during power transmission can be more reliably suppressed.

[0162] Furthermore, when a buffer member 12 is provided, it is accommodated in an accommodating recess 4c formed in the facing surfaces of the first clutch member 4a and the second clutch member 4b. This prevents positional displacement of the buffer member 12, which could occur when the first clutch member 4a moves relative to the second clutch member 4b. The accommodating recess 4c is formed in the surface of the first clutch member 4a facing the second clutch member 4b. However, the accommodating recess 4c may be formed in the surface of the second clutch member 4b facing the first clutch member 4a.

[0163] Furthermore, the aforementioned accommodating recess 4c is formed of an annular groove, and the buffer member 12 is formed of a spring having an annular shape that conforms to the shape of the groove. Therefore, the urging force generated by the buffer member 12 can be applied substantially evenly to the second clutch member 4b and the like, and the urging force can be applied stably. The aforementioned reverse torque transmission cam is formed into a plurality of annular shapes on the surfaces of the first clutch member 4a and the second clutch member 4b facing each other, and the accommodating recess 4c is formed into a concentric circular shape at a position adjacent to the reverse torque transmission cam. Therefore, the reverse torque transmission cam can reliably and stably move the second clutch member 4b, and the buffer member 12 can reliably and stably apply the urging force.

[0164] In addition, the bearing retaining member C according to this embodiment is composed of a cylindrical member with one end open, and the open end Ca is fitted and attached to the recessed portion 4d formed in the clutch member (first clutch member 4a) (attached in a spigot-type state). Therefore, the bearing retaining member C is easy to assemble and can be stably operated when performing a shifting operation.

[0165] The power transmission device includes: a release spring m that can apply an urging force to the pressure member 5 while allowing the linkage member 9 and the pressure member 5 to move until the driving-side clutch plate 6 and the driven-side clutch plate 7 reach an engaged state before the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other; and the release spring m is attached to both the bearing retaining member C and the pressure member 5, applies an urging force to the pressure member 5, and can apply the urging force to the bearing retaining member C to transmit the urging force to the actuating member 10. Therefore, the release spring m can also be used as a spring for preventing backlash in the shift operating device, and the number of components can be reduced.

[0166] Furthermore, the release spring m according to the present embodiment is composed of a conical disc spring that can generate an urging force due to displacement between the middle portion ma and the peripheral portion mb, the middle portion ma being attached to the bearing holding member C, and the peripheral portion mb being attached to the pressure member 5. Therefore, the urging force of the release spring m can be stably applied to both the bearing holding member C and the pressure member 5.

[0167] Furthermore, the clutch member according to this embodiment includes: a first clutch member 4a coupled to the output shaft 3 (output member); a second clutch member 4b to which the driven-side clutch plate 7 is attached; and a reverse torque transmission cam that, when rotational force is input to the first clutch member 4a via the output shaft 3 (output member), can press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other by moving the second clutch member 4b; and a recess 4d is formed in the first clutch member 4a. Therefore, it is possible to prevent the bearing retaining member C from interfering with the movement of the second clutch member 4b due to the reverse torque transmission cam, and it is possible to enable the reverse torque transmission cam to smoothly move each of the bearing retaining member C and the second clutch member 4b.

[0168] According to the above embodiment, the reverse torque transmission cam can move the second clutch member 4b in the direction toward the linkage member 9 to maintain contact between the linkage member 9 and the weight member 8. Therefore, the driving-side clutch plate 6 and the driven-side clutch plate 7 can be pressed against each other to transmit the rotational force on the wheel side to the engine side to apply the engine brake, and actuation can be stably performed by the weight member 8 when the engine brake is applied.

[0169] The reverse torque transmission cam according to this embodiment is composed of cam surfaces (K1, T1) integrally formed in the first clutch member 4a and the second clutch member 4b, respectively, and the cam surfaces (K1, T1) are formed in the mating surfaces of the first clutch member 4a and the second clutch member 4b, respectively. Therefore, the reverse torque transmission cam can reliably and smoothly move the second clutch member 4b.

[0170] Furthermore, the power transmission device includes a pressure-contact assist cam, which is composed of the inclined surface 4aa of the first clutch member 4a and the inclined surface 5a of the pressure member 5 facing each other, and which increases the pressure-contact force between the driving-side clutch plates 6 and the driven-side clutch plates 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 pressure-contact force generated by the movement of the weight member 8 due to centrifugal force, the pressure-contact force generated by the pressure-contact assist cam can be applied, and the driving-side clutch plates 6 and the driven-side clutch plates 7 can be pressed against each other more smoothly and more reliably.

[0171] Furthermore, the power transmission device includes a reverse torque limiter cam, which is composed of the inclined surface 4ab of the first clutch member 4a and the inclined surface 5b of the pressure member 5 facing each other, and which can release the pressing force between the driving-side clutch plate 6 and the driven-side clutch plate 7 when the rotation speed of the output shaft 3 (output member) exceeds the rotation speed of the input gear 1 (input member) and the clutch member (first clutch member 4a) and the pressure member 5 rotate relative to each other. Therefore, when the weight member 8 is in the radially outer position, it is possible to prevent excessive drive force from being transmitted to the engine side via the input gear 1, and the reverse torque transmission cam can be reliably actuated because it is actuated before the reverse torque limiter cam starts to operate.

[0172] Furthermore, this embodiment includes: a reverse torque transmission cam that, when rotational force is input to the first clutch member 4a via the output shaft 3 (output member), can move the second clutch member 4b to press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other; and a torque transmission portion formed in each of the first clutch member 4a and the second clutch member 4b, which can transmit the rotational force transmitted to the second clutch member 4b to the first clutch member 4a without using the reverse torque transmission cam (cam surface K1 and cam surface T1). Therefore, engine braking can be applied by pressing the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other to transmit the rotational force on the wheel side to the engine side, and power transmission can be stably performed when the weight member 8 moves to the radially outer position and the pressure member 5 moves to the operating position.

[0173] Furthermore, the power transmission device includes a movement limiter formed in each of the first clutch member 4a and the second clutch member 4b, which limits the amount of movement of the second clutch member 4b caused by the reverse torque transmission cam. Thus, the reverse torque transmission cam can move the second clutch member 4b within a set range.

[0174] Furthermore, a protrusion F is formed in either the first clutch member 4a or the second clutch member 4b, a torque transmission portion is constituted by one side surface F1 of the protrusion F and a first contact surface G1 that receives a rotational force by contacting the one side surface F1, and a movement amount restriction portion is constituted by the other side surface F2 of the protrusion F and a second contact surface G2 that can restrict the movement amount by contacting the other side surface F2. Therefore, the protrusion F can function as both a torque transmission portion and a movement amount restriction portion.

[0175] So far, the present embodiment has been described. However, the present invention is not limited to these. For example, Figure 25 and Figure 26 As shown, the present invention can be applied to a power transmission device in which the weight member 8 is movably provided in the housing portion 2a of the clutch housing 2. As in the above embodiment, the power transmission device includes the first clutch member 4a, the second clutch member 4b, the reverse torque transmission cam, and the buffer member 12 interposed between the first clutch member 4a and the second clutch member 4b.

[0176] Figure 25 An embodiment is shown in which the damping member 12 is attached to the surface of the first clutch member 4a facing the second clutch member 4b. Figure 26 An embodiment is shown in which a cushioning member 12 is attached to the surface of the first clutch member 4a, which applies an urging force to the stacked portion (disc pack) of the driving-side clutch plates 6 and the driven-side clutch plates 7. The bearing retaining member C' is movable by an actuating member 10', and a release spring m' is constructed from a coil spring attached to both the bearing retaining member C' and the pressure member 5.

[0177] In addition, instead of the buffer member 12 composed of a conical disc spring, another elastic member may be used. Figure 27 As shown, a buffer member 12' composed of a wave spring can be provided in the accommodating recess 4c. Figure 28 and Figure 29 As shown, the wave spring is composed of a C-shaped member having a notch 12'a in a portion of the annular shape. The wave spring has a wave shape relative to the thickness direction t and can generate an elastic force. The wave spring is placed between the first clutch member 4a and the second clutch member 4b. The wave spring is compressed during the movement of the linkage member 9 and the movement of the pressure member 5 from the non-operating position to the operating position, thereby applying an urging force while allowing the linkage member 9 and the pressure member 5 to move.

[0178] In the power transmission device shown in the figure, the bearing retaining member C has a plurality (three in this embodiment) of communication holes Cc formed in its side wall, allowing oil supplied to the interior of the bearing retaining member C to flow to the exterior via an oil flow path r. An actuating member 10" engages with the roller bearing B1 of the bearing retaining member C and, due to a driver's operation or the operation of an actuator, can move the pressure member 5 between an operative position and an inoperative position by moving in the left-right direction in the figure.

[0179] like Figure 27 As shown, the actuating member 10 ″ according to the present embodiment is of a pull type. When operated by hand or an actuator, the actuating member 10 ″ moves rightward in the figure and pulls the bearing B1 in the same direction, and thereby the actuating member 10 ″ can release the pressing force between the driving side clutch plate 6 and the driven side clutch plate 7. Figure 30 As shown, a buffer member 12' consisting of a conical disc spring can be used instead Figure 27 The buffer member 12 of the power transmission device is shown.

[0180] In addition, if Figure 31 As shown, a reverse torque transmission cam (cam surface K1 and cam surface T1) can be provided in the outer peripheral portion of each of the first clutch member 4a and the second clutch member 4b. With this power transmission device, since the reverse torque transmission cam is provided in the outer peripheral portion of each of the first clutch member 4a and the second clutch member 4b, the effect of the cam can be enhanced, and the moving force (thrusting force) of the second clutch member 4b can be set to be large.

[0181] exist Figure 31 In the power transmission device shown, no buffer member 12 or 12' is provided. However, the buffer member 12 composed of a conical disc spring may be provided on the radially inner side of the reverse torque transmission cam (cam surface K1 and cam surface T1) (see FIG. Figure 32 ), or the buffer member 12 'composed of a wave spring may be provided on the radially inner side of the reverse torque transmission cam (cam surface K1 and cam surface T1) (see Figure 33 ).

[0182] In this embodiment, the bearing retaining member C is composed of a cylindrical member with one end open, and the open end Ca is fitted and attached to the recess 4d formed in the clutch member (first clutch member 4a). However, a bearing retaining member having another shape may be used, and an attachment structure different from the configuration in which the bearing retaining member is fitted into the recess formed in the clutch member (so-called spigot joint) may be used. Note that the power transmission device according to the present invention can be applied to various multi-disc clutch power transmission devices in addition to motorcycles, automobiles, three- or four-wheeled ATVs, general-purpose machinery, and the like.

[0183] Industrial Applicability

[0184] As long as the set load of the clutch spring is set to be smaller than the maximum load of the release spring, the present invention can be applied to a power transmitting device having a different outer shape or having another additional function.

Claims

1. A power transmission device, comprising: a clutch member housed in a clutch housing that rotates together with an input member that is rotated by a driving force of an engine of a vehicle, a plurality of driving-side clutch plates attached to the clutch housing, a plurality of driven-side clutch plates formed alternately with the driving-side clutch plates of the clutch housing attached to the clutch member, and the clutch member being coupled to an output member capable of rotating wheels of the vehicle; as well as a pressure member movable between an operating position and a non-operating position, wherein in the operating position, the pressure member presses the driving side clutch plate and the driven side clutch plate against each other to enable the driving force of the engine to be transmitted to the wheels, and in the non-operating position, the pressure member releases the pressing force between the driving side clutch plate and the driven side clutch plate to enable the driving force of the engine to be stopped from being transmitted to the wheels, It is characterized by: The clutch member comprises: a first clutch member coupled to the output member; a second clutch member to which the driven side clutch plate is attached; and The plurality of clutch-side first cam portions each have a clutch-side auxiliary cam surface and a clutch-side sliding cam surface. When the clutch member rotates relative to the pressure member, the clutch-side auxiliary cam surface generates a force in a direction causing the pressure member to approach the clutch member, thereby increasing the pressing force between the driving-side clutch plate and the driven-side clutch plate. When the clutch member rotates relative to the pressure member, the clutch-side sliding cam surface causes the pressure member to separate from the clutch member, thereby reducing the pressing force between the driving-side clutch plate and the driven-side clutch plate. The clutch-side first cam portion is provided on the first clutch member, The pressure member has a plurality of pressure member side cam portions, and the plurality of pressure member side cam portions have a pressure member side auxiliary cam surface and a pressure member side sliding cam surface. When the pressure member rotates relative to the clutch member, the pressure member side auxiliary cam surface is configured to be able to contact the clutch side auxiliary cam surface and generate a force in the direction of causing the pressure member to approach the clutch member, so as to increase the pressing force between the driving side clutch plate and the driven side clutch plate. When the pressure member rotates relative to the clutch member, the pressure member side sliding cam surface is configured to be able to contact the clutch side sliding cam surface and cause the pressure member to leave the clutch member, so as to reduce the pressing force between the driving side clutch plate and the driven side clutch plate.

2. The power transmission device according to claim 1, wherein: The power transmission device includes a torque transmission portion formed in each of the first clutch member and the second clutch member, and capable of transmitting the rotational force transmitted to the second clutch member to the first clutch member.

3. The power transmission device according to claim 2, wherein: The torque transmission portion, the clutch-side assist cam surface, the clutch-side sliding cam surface, the pressure member-side assist cam surface, and the pressure member-side sliding cam surface are located on the same plane orthogonal to the axial direction of the output member.

4. The power transmission device according to claim 2, wherein: The torque transmission portion includes a clutch-side second cam portion, wherein the clutch-side second cam portion includes: a first portion formed on the clutch-side first cam portion and having a first cam surface; and a second portion formed on the second clutch member and having a second cam surface capable of abutting against the first cam surface. A circumferential length of a radially outer side of the second clutch-side cam portion is shorter than a circumferential length of a radially outer side of the first clutch-side cam portion.

5. The power transmission device according to claim 4, wherein: The clutch-side second cam portion projects radially inward from the inner peripheral surface of the second clutch member.

6. The power transmission device according to claim 2, wherein: The torque transmission portion includes a clutch-side second cam portion, wherein the clutch-side second cam portion includes: a first portion formed on the clutch-side first cam portion and having a first cam surface; and a second portion formed on the second clutch member and having a second cam surface capable of abutting against the first cam surface. The number of the clutch-side second cam portions is different from the number of the clutch-side first cam portions.

7. The power transmission device according to claim 6, wherein: The number of the clutch-side second cam portions is greater than the number of the clutch-side first cam portions.

8. The power transmission device according to claim 7, wherein: The number of the clutch-side second cam portions is an integral multiple of the number of the clutch-side first cam portions.

9. The power transmission device according to claim 2, wherein: The torque transmitting portion includes a cam portion that overlaps with the clutch-side first cam portion when viewed in the axial direction of the output member.

10. The power transmission device according to claim 1, wherein: The clutch member includes a reverse torque transmission cam, and when rotational force is input to the first clutch member via the output member, the reverse torque transmission cam can move the second clutch member to press the driving side clutch plate and the driven side clutch plate against each other. The power transmission device is configured such that the reverse torque transmission cam operates to move the second clutch member before the clutch-side sliding cam surface contacts the pressure member-side sliding cam surface and the pressure member moves away from the clutch member in order to reduce the pressing force between the driving-side clutch plate and the driven-side clutch plate.

11. A power transmission device, comprising: a clutch member housed in a clutch housing that rotates together with an input member that is rotated by a driving force of an engine of a vehicle, a plurality of driving-side clutch plates attached to the clutch housing, a plurality of driven-side clutch plates formed alternately with the driving-side clutch plates of the clutch housing attached to the clutch member, and the clutch member being coupled to an output member capable of rotating wheels of the vehicle; as well as a pressure member movable between an operating position and a non-operating position, wherein the pressure member presses the driving-side clutch plate and the driven-side clutch plate against each other to enable transmission of the driving force of the engine to the wheels, and wherein the pressure member releases the pressing force between the driving-side clutch plate and the driven-side clutch plate to stop transmission of the driving force of the engine to the wheels; It is characterized in that The clutch member comprises: a first clutch member coupled to the output member; a second clutch member to which the driven side clutch plate is attached; and a plurality of clutch-side first cam portions, each of which has a clutch-side auxiliary cam surface. When the clutch member rotates relative to the pressure member, the clutch-side auxiliary cam surface generates a force in a direction that causes the pressure member to approach the clutch member, thereby increasing the pressing force between the driving-side clutch plate and the driven-side clutch plate. The clutch-side first cam portion is provided on the first clutch member, The pressure member has a plurality of pressure member side cam portions, each of which has a pressure member side auxiliary cam surface. When the pressure member rotates relative to the clutch member, the pressure member side auxiliary cam surface is configured to be able to contact the clutch side auxiliary cam surface and generate a force in the direction of causing the pressure member to approach the clutch member, so as to increase the pressing force between the driving side clutch plate and the driven side clutch plate.

12. A power transmission device, comprising: a clutch member housed in a clutch housing that rotates together with an input member that is rotated by a driving force of an engine of a vehicle, a plurality of driving-side clutch plates attached to the clutch housing, a plurality of driven-side clutch plates formed alternately with the driving-side clutch plates of the clutch housing attached to the clutch member, and the clutch member being coupled to an output member capable of rotating wheels of the vehicle; as well as a pressure member movable between an operating position and a non-operating position, wherein the pressure member presses the driving-side clutch plate and the driven-side clutch plate against each other to enable transmission of the driving force of the engine to the wheels, and wherein the pressure member releases the pressing force between the driving-side clutch plate and the driven-side clutch plate to stop transmission of the driving force of the engine to the wheels; It is characterized in that The clutch member comprises: a first clutch member coupled to the output member; a second clutch member to which the driven side clutch plate is attached; and a plurality of clutch-side first cam portions, each of the plurality of clutch-side first cam portions having a clutch-side sliding cam surface, wherein when the clutch member rotates relative to the pressure member, the clutch-side sliding cam surface causes the pressure member to separate from the clutch member to reduce the pressing force between the driving-side clutch plate and the driven-side clutch plate; The clutch-side first cam portion is provided on the first clutch member, The pressure member has a plurality of pressure member side cam portions, and the plurality of pressure member side cam portions have a pressure member side sliding cam surface. When the pressure member rotates relative to the clutch member, the pressure member side sliding cam surface is configured to be able to contact the clutch side sliding cam surface and cause the pressure member to leave the clutch member so as to reduce the pressing force between the driving side clutch plate and the driven side clutch plate.

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