Power transmission device

Abstract

The present application provides a power transmission device capable of improving operability by suppressing suddenness in a power transmission process. The power transmission device has: 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 a driving-side clutch plate (6) and a driven-side clutch plate (7) reach an engaged state before being pressed; and a clutch spring (11) that contracts in a process in which the linkage member moves to further move the pressure member after the driving-side clutch plate and the driven-side clutch plate reach the engaged state, and that 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 a maximum load of the release spring.

Description

[0001] This application is a divisional application of the original application No. 201980079472.1 (PCT application No. PCT / JP2019 / 047408, filed on December 04, 2019, with the title of “Power transmission device”). TECHNICAL FIELD

[0002] The present application relates to a power transmission device capable of appropriately transmitting or stopping transmission of 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 transmission of 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 capable of moving 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 a driving-side clutch plate and a driven-side clutch plate against each other, and is configured to stop transmission of power by moving the pressure member away from the clutch member to release pressing force between the driving-side clutch plate and the driven-side clutch plate.

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

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

[0006] LIST OF CITATIONS

[0007] PATENT LITERATURE

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

[0009] Technical issues

[0010] However, existing power transmission devices have the following problems.

[0011] If the compression of the release spring has ended at the load (maximum load) (see...) Figure 34 If the difference between P1 in the figure and the load (set load) at the start of the compression of the clutch spring (see P2 in the figure) is large, then during the movement of the linkage component and the movement of the pressure component from the non-working position to 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 component (stops at the movement amount α1 in the figure).

[0012] Then, as the engine speed increases further and the pressing load applied to the linkage reaches the set load of the clutch spring (at moment P2 in the diagram), the clutch spring begins to compress, and the linkage starts to move again, passing through the dead zone. However, because the clutch plates are pressed against each other and power is transmitted after the dead zone has been passed, there is a sense of surprise when power is transmitted, which may affect operability.

[0013] The present invention was made with this in mind, and its object is to provide a power transmission device that can suppress the sense of surprise during power transmission and improve operability.

[0014] Solution to the problem

[0015] According to the first aspect, a power transmission apparatus includes: a clutch housing that rotates with an input member, the input member being rotated by a driving force of an engine of a vehicle, and a plurality of driving-side clutch plates attached to the clutch housing; a clutch member to which a plurality of driven-side clutch plates alternately formed with the plurality of driving-side clutch plates of the clutch housing are attached, and the clutch member being 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 plurality of driving-side clutch plates and the plurality of driven-side clutch plates against each other 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 a pressing force between the plurality of driving-side clutch plates and the plurality of driven-side clutch plates to be capable of stopping the transmission of the driving force of the engine to the wheel; a counterweight member that is provided in a groove portion extending in a radial direction of the clutch housing, and the counterweight member being movable in the groove portion from a radially inner side position to a radially outer side position due to a centrifugal force generated when the clutch housing rotates; a link member that is capable of moving the pressure member from the non-operating position to the operating position when the counterweight member moves from the radially inner side position to the radially outer side position; a release spring that is capable of holding the pressure member in the non-operating position, the release spring being compressed when the link member moves and the pressure member moves from the non-operating position toward the operating position, and the release spring being capable of applying an urging force while allowing the link 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 that is compressed in a process in which the link member moves after the plurality of driving-side clutch plates and the plurality of driven-side clutch plates have reached the engaged state, and the clutch spring being 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 link 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 second aspect, the power transmission apparatus of the first aspect includes a buffer member that is capable of applying an urging force while allowing the link member and the pressure member to move by being compressed in a process in which the link member moves and the pressure member moves from the non-operating position toward the operating position.

[0017] According to the invention of the third aspect, in the power transmission apparatus of the second aspect, the buffer member is constituted by a spring having a set load that causes the spring to be compressed before the clutch spring starts to be compressed.

[0018] Advantages of the Invention

[0019] With the invention of the first aspect, it is possible to avoid occurrence of a dead zone and improve operability by suppressing a sense of strangeness at the time of power transmission, because the set load of the clutch spring is set to be smaller than the maximum load of the release spring, so compression of the release spring and compression of the clutch spring are continuously performed, and the link member continuously moves.

[0020] With the invention of the second aspect, it is possible to avoid a dead zone and further suppress a sense of strangeness at the time of power transmission and improve operability when the buffer member or the clutch spring is continuously compressed during compression of the release spring, because the power transmission apparatus includes a buffer member that is able to apply a urging force by being compressed during movement of the link member and movement of the pressure member from the non-working position toward the working position, while allowing movement of the link member and the pressure member.

[0021] With the invention of the third aspect, it is possible to reliably suppress a sense of strangeness at the time of power transmission, because the buffer member is constituted by a spring having a set load that causes the spring to be compressed before the clutch spring starts to be compressed. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0024] [ Figure 3 ] is a schematic view of a drive-side clutch plate, a driven-side clutch plate, a reverse torque transmission cam, and the like of a power transmission apparatus.

[0025] [ Figure 4 ] is a perspective view of a housing portion of a clutch housing of a power transmission apparatus.

[0026] [ Figure 5 ] is a perspective view of a cover portion of a clutch housing of a power transmission apparatus.

[0027] [ Figure 6 ] is a three-side view of a first clutch member of a power transmission apparatus.

[0028] [ Figure 7FIG. 6 is a three-side view of a second clutch member of the power transmission device.

[0029] [ Figure 8 FIG. 7 is a three-side view of a pressure member of the power transmission device.

[0030] [ Figure 9 FIG. 8 is a perspective view illustrating the first clutch member, the second clutch member, the pressure member, and the bearing holding member of the power transmission device before assembly.

[0031] [ Figure 10 FIG. 9 is a perspective view illustrating the first clutch member, the second clutch member, the pressure member, and the bearing holding member of the power transmission device before assembly.

[0032] [ Figure 11 FIG. 10 is a perspective view illustrating the first clutch member, the second clutch member, the pressure member, and the bearing holding member of the power transmission device after assembly.

[0033] [ Figure 12 FIG. 11 is a three-side view of a bearing holding member of the power transmission device.

[0034] [ Figure 13 FIG. 12 is a schematic view illustrating the function of a crimping assist cam of the power transmission device.

[0035] [ Figure 14 FIG. 13 is a schematic view illustrating the function of a reverse torque limiter cam of the power transmission device.

[0036] [ Figure 15 FIG. 14 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 portion and the first contact surface (torque transmission portion) are in contact with each other.

[0037] [ Figure 16 FIG. 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 the other side surface of the protrusion portion and the second contact surface (movement amount limiting portion) are in contact with each other.

[0038] [ Figure 17 FIG. 16 is a schematic view 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 work.

[0039] [ Figure 18 FIG. 17 is a schematic view 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 to work.

[0040] [ Figure 19FIG. 1 is a perspective view of a power transmission device according to an embodiment of the present application.

[0041] [ Figure 20 FIG. 2 is a perspective view of a power transmission device according to another embodiment of the present application.

[0042] [ Figure 21 FIG. 3 is a perspective view of a power transmission device according to another embodiment of the present application.

[0043] [ Figure 22 FIG. 4 is a graph showing the movement amount and pressing load of a power transmission device according to another embodiment of the present application.

[0044] [ Figure 23 FIG. 5 is a graph showing the movement amount and pressing load of a power transmission device according to another embodiment of the present application.

[0045] [ Figure 24 FIG. 6 is a longitudinal sectional view of a power transmission device according to another embodiment of the present application.

[0046] [ Figure 25 FIG. 7 is a longitudinal sectional view of a power transmission device according to another embodiment of the present application.

[0047] [ Figure 26 FIG. 8 is a longitudinal sectional view of a power transmission device according to another embodiment of the present application.

[0048] [ Figure 27 FIG. 9 is a longitudinal sectional view of a power transmission device according to another embodiment of the present application (provided with a buffer member 12' and including a pull-type actuating member 10").

[0049] [ Figure 28 FIG. 10 is a plan view and a side view of a buffer member of a power transmission device.

[0050] [ Figure 29 FIG. 11 is a perspective view of a buffer member of a power transmission device.

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

[0052] [ Figure 31 FIG. 13 is a longitudinal sectional view of a power transmission device according to another embodiment of the present application (provided with a reverse torque transmission cam at the outer edge of the first clutch member 4a).

[0053] [ Figure 32FIG. 7 is a longitudinal sectional view of a power transmission apparatus according to another embodiment of the present application (a reverse torque transmission cam is provided at an outer edge of the first clutch member 4a, and a buffer member composed of a wave spring is provided).

[0054] [ Figure 33 FIG. 8 is a longitudinal sectional view of a power transmission apparatus according to another embodiment of the present application (a reverse torque transmission cam is provided at an outer edge of the first clutch member 4a, and a buffer member composed of a wave spring is provided).

[0055] [ Figure 34 FIG. 9 is a graph showing the moving amount and the pressing load of the linkage member of the conventional power transmission apparatus.

[0056] LIST OF REFERENCE NUMERALS

[0057] 1 input gear (input member)

[0058] 2 clutch housing

[0059] 2a housing portion

[0060] 2b cover portion

[0061] 3 output shaft (output member)

[0062] 4a first clutch member

[0063] 4aa inclined surface (crimping 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 portion

[0069] 4bb pressing portion

[0070] 4c accommodating recess

[0071] 4d recess

[0072] 4da inner peripheral wall surface

[0073] 5 pressure member

[0074] 5a inclined surface (crimping 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 member

[0080] 9 link member

[0081] 10 actuation member

[0082] 11 clutch spring

[0083] 12 cushion member (coned disc spring)

[0084] 12' cushion member (wave spring)

[0085] 12'a cutout portion

[0086] C bearing holding member

[0087] Ca open end portion

[0088] Cb top portion

[0089] Cc communication hole

[0090] K groove portion

[0091] K1 cam surface

[0092] K2 wall surface

[0093] T protrusion

[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 application 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 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 FIG. 1, the power transmission device according to the present embodiment is provided with a clutch 1, a transmission 2, a drive shaft 3, aFigures 1 to 12 As shown in FIG. 1, the power transmission device mainly includes: a clutch housing 2 in which an input gear 1 (input member) that rotates by a driving force of an engine of a vehicle is formed; clutch members (a first clutch member 4a and a second clutch member 4b); a pressure member 5 that is attached to the clutch members (the first clutch member 4a and the second clutch member 4b) of the clutch housing 2 and that is configured to be movable in the axial direction of the clutch housing 2; a plurality of driving-side clutch plates 6; a plurality of driven-side clutch plates 7; a counterweight member 8 that is configured of a steel ball member that is movable (rollable) in the radial direction in the clutch housing 2; a link member 9; and an actuating member 10 that is actuable by hand or an actuator (not shown). The symbol S in the drawing represents a spring damper, the symbol B1 represents a roller bearing, and the symbols B2 and B3 represent thrust bearings, respectively. Figure 2 As shown in FIG. 1, the power transmission device mainly includes: a clutch housing 2 in which an input gear 1 (input member) that rotates by a driving force of an engine of a vehicle is formed; clutch members (a first clutch member 4a and a second clutch member 4b); a pressure member 5 that is attached to the clutch members (the first clutch member 4a and the second clutch member 4b) of the clutch housing 2 and that is configured to be movable in the axial direction of the clutch housing 2; a plurality of driving-side clutch plates 6; a plurality of driven-side clutch plates 7; a counterweight member 8 that is configured of a steel ball member that is movable (rollable) in the radial direction in the clutch housing 2; a link member 9; and an actuating member 10 that is actuable by hand or an actuator (not shown). The symbol S in the drawing represents a spring damper, the symbol B1 represents a roller bearing, and the symbols B2 and B3 represent thrust bearings, respectively.

[0104] When the driving force (rotational force) transmitted from the engine is input, the input gear 1 is rotatable about 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 housing portion 2a that is configured of a cylindrical member (which is open at the right side in FIG. 1) and that is coupled to the input gear 1, and a cover portion 2b that is attached so as to close the opening of the housing portion 2a. The clutch housing 2 is rotatable with the rotation of the input gear 1 due to the driving force of the engine. Figure 2

[0105] As shown in FIG. 1, 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 driving-side clutch plates 6 are attached so as to fit to the cutouts 2aa. Each driving-side clutch plate 6 is configured of a substantially annular plate material, is configured to be rotatable with the rotation of the clutch housing 2, and is slidable in the axial direction (left-right direction in FIG. 1). Figure 4 Figure 2

[0106] Further, as shown in FIG. 1, a plurality of groove portions 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. The counterweight member 8 is provided in each of the plurality of groove portions 2ba. 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 is rotating at low speed, the counterweight member 8 is located at a radially inner position (position shown in FIG. 1). In a state in which the clutch housing 2 is rotating at high speed, the counterweight member 8 is located at a radially outer position. Figure 5 Figure 2

[0107] ​​​​​A plurality of driven-side clutch plates 7 formed alternately with the drive-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 an output shaft 3 (output member) capable of rotating the wheels of the vehicle. The clutch members are constituted by assembling the two members of the first clutch member 4a and the second clutch member 4b.

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

[0109] As shown in Figure 7 , the second clutch member 4b is constituted by a ring-shaped member, and is configured so that the driven-side clutch plates 7 are attached to spline-fitting portions 4ba (see Figure 2 and Figure 7 ) formed in the outer peripheral surface thereof by spline-fitting. As shown in Figures 9 to 11 , the pressure member 5 is assembled together with the clutch members (first clutch member 4a and second clutch member 4b). The plurality of drive-side clutch plates 6 and driven-side clutch plates 7 in the alternately stacked state are attached between a flange surface 5c (see Figure 2 and Figure 8 ) of the pressure member 5 and a flange surface 4ac (see Figure 2 and Figure 6 ) of the first clutch member 4a.

[0110] As shown in Figure 8 , the pressure member 5 is constituted by a disc-shaped member, and the flange surface 5c is formed along a peripheral edge portion thereof. The pressure member 5 is movable between an operating position, in which the pressure member 5 presses the drive-side clutch plates 6 and the driven-side clutch plates 7 against each other to enable transmission of the driving force of the engine to the wheels, and a non-operating position, in which the pressure member 5 releases the crimping force between the drive-side clutch plates 6 and the driven-side clutch plates 7 to enable stopping of the transmission of the driving force of the engine to the wheels (see Figure 2 ).

[0111] More specifically, as shown in Figure 7 ,Figure 9 and Figure 10 As shown in FIG. 6, the spline engagement portion 4ba formed in the second clutch member 4b has a protrusion / recess shape that is integrally formed along substantially the entire circumference of the outer peripheral side surface of the second clutch member 4b. When the driven-side clutch plate 7 is fitted into the recess of the spline engagement portion 4ba, movement of the driven-side clutch plate 7 in the rotational direction is restricted, while allowing movement of the driven-side clutch plate 7 in the axial direction with respect 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 plate 7 is stacked alternately with the drive-side clutch plate 6, and the clutch plates 6 and 7 can be pressed against each other, or the pressing force therebetween can be released. That is, both of the clutch plates 6 and 7 are allowed to slide in the axial direction of the second clutch member 4b. When the pressure member 5 moves to the left in FIG. 5 and its flange surface 5c moves toward the flange surface 4ac of the first clutch member 4a, both of 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. When the pressure member 5 moves to the right in FIG. 5 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. Figure 2 Figure 2

[0113] In a state where the drive-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other, the rotational force input to the clutch housing 2 (the driving force of the engine) is transmitted to the wheel side via the output shaft 3 (output member). In a state where the pressing between the drive-side clutch plate 6 and the driven-side clutch plate 7 is released, the rotational force input to the clutch housing 2 (the driving force of the engine) can be prevented from being transmitted to the output shaft 3 (output member).

[0114] Further, as shown in Figure 6 , Figure 8 , Figure 9 and Figure 10 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 pressing-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] As shown in FIG. 6, the spline engagement portion 4ba formed in the second clutch member 4b has a protrusion / recess shape that is integrally formed along substantially the entire circumference of the outer peripheral side surface of the second clutch member 4b. When the driven-side clutch plate 7 is fitted into the recess of the spline engagement portion 4ba, movement of the driven-side clutch plate 7 in the rotational direction is restricted, while allowing movement of the driven-side clutch plate 7 in the axial direction with respect to the second clutch member 4b, and the driven-side clutch plate 7 can rotate together with the second clutch member 4b. Figure 13 ​​As shown, when the engine speed increases and the rotational force input to the input gear 1 and 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 counterweight member 8 is in a radially outward position). Therefore, due to the action of the press-fit auxiliary cam, a force in direction c is generated in the pressure member 5. Consequently, the flange surface 5c of the pressure member 5 moves further toward the flange surface 4ac of the first clutch member 4a (…). Figure 2 The clutch moves from center to left, and the pressure member 5 increases the pressure between the drive-side clutch plate 6 and the driven-side clutch plate 7.

[0116] On the other hand, when the vehicle is in motion, when the rotational speed of the output shaft 3 exceeds the rotational speed of the input gear 1 and the clutch housing 2, and generates along... Figure 14 When the reverse torque is applied in direction b, the pressure member 5 moves in direction d as shown in the figure due to the action of the reverse torque limiter cam, thereby releasing the pressure force between the drive-side clutch plate 6 and the driven-side clutch plate 7. This avoids damage to the power transmission device and power source (engine side) caused by the reverse torque.

[0117] The counterweight member 8 is disposed in a groove 2ba extending radially along the clutch housing 2 (in this embodiment, the cover 2b). Due to the centrifugal force generated when the clutch housing 2 rotates, the counterweight member 8 is positioned radially inward from the groove 2ba (see...). Figure 2 The counterweight member 8 moves to the radially outer position to press the driving-side clutch plate 6 and the driven-side clutch plate 7 against each other. That is, the rolling surface (bottom surface) of the groove 2ba for the counterweight member 8 to roll has an upward slope from the radially inner position to the radially outer position. When the clutch housing 2 stops, the counterweight member 8 is held in the radially inner position due to the actuating force of the release spring m. When the clutch housing 2 rotates, centrifugal force is applied to the counterweight member 8, and when the clutch housing 2 reaches a predetermined speed, the counterweight member 8 moves along the upward slope to the radially outer position.

[0118] The linkage member 9 is composed of an annular member disposed in the clutch housing 2 (cover 2b). The linkage member 9 engages with a groove formed in the inner circumferential surface of the cover 2b, and can rotate together with the clutch housing 2. Figure 2 It moves in the left and right directions. When the counterweight component 8 moves from the radially inner position to the radially outer position, the linkage component 9 overcomes the actuating force of the clutch spring 11 and the release spring m. Figure 2 The pressure member 5 can be moved to the left and pressed to move it from the non-working position to the working position.

[0119] Actuating component 10 can be operated by hand or actuator (see...) Figure 2) the pressure member 5 between the driving side clutch plate 6 and the driven side clutch plate 7 can be released Figure 2 to the right). When a shift operation is performed, for example, by operation of a clutch pedal, a clutch lever, or the like of the vehicle or by work of an actuator, the actuating member 10 is moved to the right to contact the pressure member 5 via the bearing holding member C and move the pressure member 5 from the working position to the non-working position. Thus, 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 power transmission). Figure 2

[0120] As shown in Figure 2 , 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. As shown in Figure 12 , the bearing holding member C is composed of a tubular member with one end open and includes an open end portion Ca and a top portion Cb on the opposite side of the open end portion Ca. The bearing B1 according to the present embodiment is attached to the top portion Cb side in the bearing holding member C, and the tubular portion extends from the diameter-increased portion toward the open end portion Ca. In addition, although a ball bearing is used as the bearing B1 according to the present embodiment, another bearing such as a needle bearing or the like can be used.

[0121] In addition, as shown in Figure 2 and Figure 20 , the open end portion Ca of the bearing holding member C according to the present embodiment is fitted and attached into a recess 4d formed in the clutch member (first clutch member 4a) and assembled with an inner peripheral wall surface 4da of the recess 4d by spigot joint (mortise joint). The recess 4d is composed of a circular recess whose shape is similar to the outer shape of the open end portion Ca and has substantially the same size as the outer shape of the open end portion Ca (strictly speaking, the size is slightly larger than the open end portion Ca). By fitting the bearing holding member C into the recess 4d, positioning and centering with respect to the power transmission device are performed.

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

[0123] ​​The release spring m can hold the pressure member 5 in the non-working position and be compressed when the link member 9 moves and the pressure member 5 moves from the non-working position toward the working position. The release spring m can exert the urging force while allowing the link member 9 and the pressure member 5 to move until the drive-side clutch plate 6 and the driven-side clutch plate 7 reach the engaged state before being pressed against each other (a state in which the distance between the drive-side clutch plate 6 and the driven-side clutch plate 7 is zero and immediately before power transmission due to pressing).

[0124] Further, as Figure 21 indicated, the release spring m according to the present embodiment is constituted by a coned disc spring that can generate an urging force due to displacement between an intermediate portion ma and a peripheral portion mb. As Figure 2 and Figure 20 indicated, the intermediate portion ma is attached to the top portion 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 that protrudes annularly, and the peripheral portion mb of the release spring m is engaged with and attached to a ring-shaped member g (e.g., a snap ring or the like) attached to the protrusion 5d. Thus, the release spring m according to the present embodiment is attached to both the bearing holding member C and the pressure member 5, exerts an urging force (an urging force in the orientation indicated by the numeral a2 in the figure) to the pressure member 5, and can exert an urging force (an urging force in the orientation indicated by the symbol al in the figure) to the bearing holding member C to transmit the urging force to the actuation member 10. Figure 20

[0125] The clutch spring 11 is constituted by a coil spring interposed between the link member 9 and the pressure member 5. The clutch spring 11 can press the pressure member 5 to move the pressure member 5 in the direction in which the drive-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other when the link member 9 moves. Further, the clutch spring 11 can absorb the pressing force exerted by the pressure member 5 to the link member 9 when the actuation member 10 is operated.

[0126] The clutch spring 11 according to the present embodiment is compressed during movement of the link member 9, and can exert a pressing force between the drive-side clutch plate 6 and the driven-side clutch plate 7 while allowing the link member 9 to move until the drive-side clutch plate 6 and the driven-side clutch plate 7 reach the above-mentioned engaged state.

[0127] That is, when the weight member 8 moves from the radially inner position to the radially outer position and the link member 9 is pressed by the weight member 8 while the clutch housing 2 is rotating, the pressing force is transmitted to the pressure member 5 via the clutch spring 11 to move the pressure member 5 in the direction in which the drive-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other. Figure 2 ​moves to the left, and the drive-side clutch plate 6 and the driven-side clutch plate 7 are pressed against each other. When the actuating member 10 is actuated in this state, although the pressure member 5 moves to the right in the figure due to the pressing force of the actuating member 10, the pressing force applied to the link member 9 is absorbed by the clutch spring 11, and the position of the link member 9 (the position of the counterweight 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 drive-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). As shown in Figure 6 、 Figure 7 、 Figure 9 and Figure 10 The reverse torque transmission cam is composed of cam surfaces (K1, T1) that are integrally formed in the mating surfaces (mating surfaces when combined) of the first clutch member 4a and the second clutch member 4b, respectively.

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

[0130] As shown in Figure 7 and Figure 10 The cam surface T1 is composed of a plurality of inclined surfaces formed along the entire circumference of the bottom surface of the second clutch member 4b (mating surface with the first clutch member 4a). The cam surface T1 is formed in one end surface of each of a plurality of protrusions T that are annularly formed along the bottom surface of the second clutch member 4b. That is, a plurality of protrusions T are formed in the second clutch member 4b so as to be arranged in the circumferential direction thereof, 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 that extends in the axial direction of the second clutch member 4b.

[0131] As shown in Figure 17As shown, when the protrusion T is fitted into the groove K to engage the first clutch member 4a and the second clutch member 4b, the cam surface K1 and the cam surface T1 face each other to form a reverse torque transmission cam, and the wall surface K2 and the wall surface T2 face each other at a predetermined distance between them. When a rotational force is input to the first clutch member 4a via the output shaft 3, because the first clutch member 4a rotates relative to the second clutch member 4b, as... Figure 18 As shown, due to the cam action of cam surface K1 and cam surface T1, the second clutch component 4b is relative to the first clutch component 4a at... Figure 2 and Figure 18 Move to the right from the center.

[0132] like Figure 7 As shown, the pressing part 4bb is formed in the second clutch member 4b on the extension line of the spline engagement part 4ba. When the second clutch member 4b is in Figure 2 When the pressure member 5 moves to the right, the pressing part 4bb presses the leftmost driven clutch plate 7 in the same direction. The driven clutch plate 7 is one of the drive clutch plate 6 and the driven clutch plate 7 that are attached in a stacked state. Therefore, even when the pressure member 5 is in the non-operating position, the drive clutch plate 6 and the driven clutch plate 7 can be pressed against each other, and when a 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] Specifically, according to this embodiment, the reverse torque transmission cam can cause the second clutch member 4b to move in the direction toward the linkage member 9 ( Figure 2 The cam moves upward (from center to right) to maintain contact between the linkage component 9 and the counterweight component 8. That is, when the reverse torque transmission cam starts working and causes the second clutch component 4b to... Figure 2 When the clutch moves to the right, the reverse torque transmission cam presses the drive-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 linkage member 9 and the counterweight member 8 are separated when the reverse torque transmission cam is engaged, the linkage member 9 cannot follow the movement of the counterweight member 8 as it moves between a radially inward position and a radially outward position as the clutch housing 2 rotates. In contrast, in this embodiment, the contact between the linkage member 9 and the counterweight member 8 can be maintained even when the reverse torque transmission cam is engaged, so the linkage member 9 can stably follow the movement of the counterweight member 8.

[0135] Further, the plurality of cam surfaces K1 and T1 of the reverse torque transmission cam according to the present embodiment are formed along the annular shape of the driven-side clutch plate 7 attached to the second clutch member 4b. That is, the cam surfaces K1 and T1 are formed along the projected image shape (annular shape) of the driven-side clutch plate 7, which is pressed by the pressing portion 4bb when the reverse torque transmission cam is in operation. Therefore, due to the cam action of the reverse torque transmission 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 drive-side clutch plate 6 and the driven-side clutch plate 7 against each other.

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

[0137] Further, the power transmission device according to the present embodiment includes a torque transmission portion that is formed in each of the first clutch member 4a and the second clutch member 4b, and that 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 that is formed in each of the first clutch member 4a and the second clutch member 4b, and that 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, as shown in Figure 6 and Figure 9 , a plurality of (three in the present embodiment) protruding portions F are integrally formed in the first clutch member 4a so as to be arranged at regular intervals in the circumferential direction. As shown in Figure 7 and Figure 9 , inwardly extending protruding portions G are integrally formed in the second clutch member 4b. As shown in Figure 15 and Figure 16 , when the first clutch member 4a and the second clutch member 4b are assembled together, one protruding portion F is interposed between the 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 protruding portion G face each other.

[0139] A side surface F1 of the protrusion F formed in the first clutch member 4a and a first contact surface G1 of the protrusion G formed in the second clutch member 4b constitute the torque transmission part according to this embodiment. That is, as Figure 15 As shown, when the pressure member 5 moves to the working position to press the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other and engage the clutch (transmitting driving force), the wall surface K2 of the groove K and the wall surface T2 of the protrusion T of the reverse torque transmission cam remain separated (see...). 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 limiting part according to this embodiment. That is, when a 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 K and the cam surface T1 of the protrusion T of the reverse torque transmission cam (see...). Figure 18 When the movement reaches the set value, such as... 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. Therefore, when the reverse torque transmission cam is working, the amount of movement 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 may be formed in the first clutch member 4a, and the protrusion F may 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 the protrusion G formed in the first clutch member 4a constitute the torque transmission part 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 limiting part according to this embodiment.

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

[0143] like Figure 2As shown, when the engine is stopped or idling, since the driving force of the engine is not transmitted to the input gear 1, or the rotational speed of the input gear 1 is low, the counterweight member 8 is in the radially inner side position, and the pressure member 5 is in the non-working position. At this time, when a rotational force is input to the first clutch member 4a via the output shaft 3 (output member), the second clutch member 4b moves to the right in the figure due to the cam action of the reverse torque transmission cam, 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 been stopped or idling, the rotational speed of the input gear 1 changes from the low rotational speed to the high rotational speed (intermediate rotational speed range), the counterweight member 8 is positioned between the radially inner side position and the radially outer side position, and the pressure member 5 is in the working position. At this time, when a 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, the second clutch member 4b moves to the right in the figure due to the cam action of the reverse torque transmission cam, 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] When the vehicle starts moving after having been stopped or idling, the rotational speed of the input gear 1 changes from the low rotational speed to the high rotational speed (intermediate rotational speed range), the counterweight member 8 is positioned between the radially inner side position and the radially outer side position, and the pressure member 5 is in the working position. At this time, when a 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, the second clutch member 4b moves to the right in the figure due to the cam action of the reverse torque transmission cam, 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 the present 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 rotational speed of the engine increases and the counterweight member 8 moves from the radially inner side position to the radially outer side position, in the process in which the link member 9 is pressed by the counterweight member 8 and moves, when the release spring m is compressed and exceeds the set load of the clutch spring 11, the clutch spring 11 starts to be compressed, and thus it is possible to avoid the occurrence of a dead zone.

[0147] Subsequently, the function of the power transmission device of the present embodiment will be described in comparison with the existing 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, the function of the power transmission device according to the present embodiment will be described with reference to FIG. 1. Figure 34The function of the existing power transmission device is described by a graph (a graph with the amount of movement (mm) of the link member 9 along the horizontal axis and the pressing load (N) generated in the link member 9 along the vertical axis). In the graph, Figure 34 P1 indicates the pressing load of the link member 9 when the amount of deformation (compression amount) of the release spring m is maximum (when the maximum load of the release spring m is reached), and P2 indicates the pressing load of the link member 9 when the clutch spring 11 starts to be deformed (when the set load of the clutch spring 11 is reached).

[0149] In the process in which the rotation speed of the engine increases and the weight member 8 moves from the radially inner side position to the radially outer side position to move the link member 9, the release spring m is deformed and the clutch spring 11 is not deformed (i.e., the link member 9 moves together with the pressure member 5) until the amount of movement of the link member 9 reaches a1, and, when the amount of movement of the link member 9 reaches a1, the link member 9 stops moving, becoming a dead zone, although the pressing load (N) increases from P1 to P2.

[0150] When the pressing load (N) reaches P2 (the set load of the clutch spring 11) from this state, the clutch spring 11 starts to be deformed, and the pressing load (N) increases with the movement of the link member 9. Therefore, the link 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 starts to be compressed, the clutch plates (the drive side clutch plate 6 and the driven side clutch plate 7) are pressed against each other to transmit power, and thus an unexpected feeling is generated when the power is transmitted.

[0151] In contrast, in the present 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. Therefore, as Figure 22 indicated in the graph, in the process in which the link member 9 moves, the release spring m is compressed and deformed, and, when the amount of movement of the link member 9 reaches a2, the release spring m reaches the set load P2 of the clutch spring 11, the clutch spring 11 starts to be compressed (deformed). Subsequently, when the amount of movement of the link member 9 reaches a1, the release spring m reaches the maximum load P1, and, when the release spring m stops being further compressed (deformed), the clutch spring 11 is compressed and deformed, so the link member 9 continuously moves.

[0152] That is, according to this drawing, the release spring m is continuously compressed (deformed) until the movement amount of the link member 9 reaches a2 in the process in which the rotation speed of the engine increases and the weight member 8 moves from the radially inner side position to the radially outer side position, thereby moving the link member 9, and when the movement amount of the link member 9 becomes a2 and the pressing load (N) reaches the set load P2 of the clutch spring 11, the clutch spring 11 starts to be deformed together with the release spring m. Subsequently, when the movement amount of the link member 9 reaches a1, the release spring m reaches the maximum load P1 and stops deforming, and the clutch spring 11 continues to be deformed (compressed), so the link member 9 continuously moves.

[0153] Therefore, before the movement amount of the link member 9 becomes a1 (before the pressing load becomes P1), only the release spring m is deformed until the movement amount of the link member 9 becomes a2, and both the release spring m and the clutch spring 11 are deformed until the movement amount of the link member 9 becomes a1, so the link member 9 continuously moves. When the movement amount of the link member 9 becomes a1 and the pressing load reaches the maximum load P1 of the release spring, the release spring m stops deforming, and the clutch spring 11 continues to be deformed, thereby allowing the link member 9 to continuously move. Therefore, it is possible to reduce the existing dead zone and to smoothly and continuously move the weight member 8 and the link member 9, so it is possible to suppress the impact at the time of clutch engagement and to suppress the sense of strangeness at the time of power transmission.

[0154] This embodiment does not have a spring or the like between the first clutch member 4a and the second clutch member 4b. However, for example, a buffer member 12 can 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 apply urging force by being compressed (spring deformation) in the process in which the link member 9 moves and the pressure member 5 moves from the non-working position toward the working position, while allowing the link member 9 and the pressure member 5 to move.

[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. As shown in Figs. 9 and 10, the buffer member 12 is assembled by being housed in a housing recess 4c formed in a surface (specifically, a surface of the first clutch member 4a facing the second clutch member 4b) of the first clutch member 4a and the second clutch member 4b facing each other. Figure 2 Figure 3 Figure 19 The housing recess 4c is composed of an annular groove, and the buffer member 12 is composed of a coned disc spring having an annular shape that conforms to the shape of the groove. As shown in Figs. 9 and 10, the buffer member 12 is assembled by being housed in a housing recess 4c formed in a surface (specifically, a surface of the first clutch member 4a facing the second clutch member 4b) of the first clutch member 4a and the second clutch member 4b facing each other.

[0156] The housing recess 4c is composed of an annular groove, and the buffer member 12 is composed of a coned disc spring having an annular shape that conforms to the shape of the groove. As shown in Figs. 9 and 10, the buffer member 12 is assembled by being housed in a housing recess 4c formed in a surface (specifically, a surface of the first clutch member 4a facing the second clutch member 4b) of the first clutch member 4a and the second clutch member 4b facing each other. Figure 19 ​​As shown, the receiving recess 4c is formed by a groove having a wall surface 4ca with a radially inner side and a wall surface 4cb with a radially outer side; and a buffer member 12, which is made of an annular spring, conforms to the shape of the groove and is assembled into the receiving recess 4c.

[0157] According to this embodiment, the reverse torque transmission cam is formed in multiple annular shapes on the surfaces of the first clutch member 4a and the second clutch member 4b that face each other. For example... Figure 6 As shown, the receiving recess 4c is formed in a concentric circle shape at a position adjacent to the reverse torque transmission cam (in this embodiment, radially inside the position where the reverse torque transmission cam is formed).

[0158] The buffer member 12 is set to a load (P3) such that the buffer member 12 is compressed before the clutch spring 11 begins to compress. Therefore, as Figure 23 As shown, before the movement of the linkage member 9 becomes α1 (before the pressing load becomes P1), only the release spring m deforms until the movement of the linkage member 9 becomes α2. Both the release spring m and the clutch spring 11 deform until the movement of the linkage member 9 becomes α3. Subsequently, the release spring m, the clutch spring 11, and the buffer member 12 all deform until the movement of the linkage member 9 becomes α1, thus allowing the linkage member 9 to move continuously. When the movement of the linkage member 9 becomes 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 the buffer member 12 stop deforming, while the clutch spring 11 continues to deform, thereby allowing the linkage member 9 to move continuously. Therefore, in the same situation, the existing dead zone can be reduced, and the counterweight member 8 and the linkage member 9 can move smoothly and continuously, thus suppressing the impact during clutch engagement and the unexpected sensation during power transmission.

[0159] When the buffer member 12 is configured as described above, the receiving recess 4c is formed in a concentric circle shape at a position radially inner to the position of the reverse torque transmission cam. However, the receiving recess 4c can also be formed in a concentric circle shape at a position radially outer to the position of the reverse torque transmission cam. In this case, as... Figure 24 As shown, the buffer member 12 can be configured to apply actuating force to the stacked portion (disc assembly) of the drive-side clutch disc 6 and the driven-side clutch disc 7 in the direction in which the drive-side clutch disc 6 and the driven-side clutch disc 7 press against each other.

[0160] In this embodiment, since the set load of the clutch spring 11 is set to be less 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 performed continuously, and the linkage member 9 moves continuously. Therefore, dead zones can be avoided and operability can be improved by suppressing the unexpected feeling during power transmission.

[0161] In the case where the power transmission device includes the buffer member 12, which can apply the urging force by being compressed during movement of the link member 9 and movement of the pressure member 5 from the non-working position toward the working position while allowing the link member 9 and the pressure member 5 to move, when the buffer member 12 or the clutch spring 11 is compressed during release of the compression of the spring m, the dead zone can be avoided, and the unexpected feeling at the time of transmission of the power can be further suppressed, and the operability can be improved. Further, in the case where the buffer member 12 is provided, since the buffer member 12 is constituted by a spring having a set load that causes the spring to be compressed before the clutch spring 11 starts to be compressed, the unexpected feeling at the time of transmission of the power can be more reliably suppressed.

[0162] Further, in the case where the buffer member 12 is provided, the buffer member 12 is housed in the housing recess 4c formed in the surface of the first clutch member 4a and the second clutch member 4b facing each other. Thus, the positional displacement of the buffer member 12 that can occur in the case where the first clutch member 4a moves relative to the second clutch member 4b can be avoided. The housing recess 4c is formed in the surface of the first clutch member 4a facing the second clutch member 4b. However, the housing recess 4c can be formed in the surface of the second clutch member 4b facing the first clutch member 4a.

[0163] Further, the above-described housing recess 4c is constituted by a ring-shaped groove, and the buffer member 12 is constituted by a spring having a ring-shaped shape that conforms to the shape of the groove. Thus, the urging force generated by the buffer member 12 can be substantially uniformly applied to the second clutch member 4b and the like, and the urging force can be stably applied. The above-described reverse torque transmission cam is formed in a plurality of ring-shaped shapes in the surfaces of the first clutch member 4a and the second clutch member 4b facing each other, and the housing recess 4c is formed in a concentric circular shape at a position adjacent to the reverse torque transmission cam. Thus, the reverse torque transmission cam can be allowed to reliably and stably move the second clutch member 4b, and the buffer member 12 can be allowed to reliably and stably apply the urging force.

[0164] In addition, the bearing holding member C according to the present embodiment is constituted by a cylindrical member with one end open, and the open end portion Ca is fitted and attached to the recess 4d formed in the clutch member (the first clutch member 4a) (in a spigot-fitting state). Thus, the bearing holding member C is easily assembled, and the bearing holding member C can be stably operated at the time of performing the shift operation.

[0165] The power transmission device includes a release spring m that can apply urging force to the pressure member 5 while allowing the link member 9 and the pressure member 5 to move until the drive-side clutch plate 6 and the driven-side clutch plate 7 reach the engaged state before the drive-side clutch plate 6 and the driven-side clutch plate 7 press against each other, and that is attached to both the bearing holding member C and the pressure member 5, applies urging force to the pressure member 5, and can apply urging force to the bearing holding member C to transmit the urging force to the actuation member 10. Therefore, the release spring m can also be used as a spring that prevents backlash of the shift operation device, and the number of components can be reduced.

[0166] Further, the release spring m according to the present embodiment is composed of a coned disc spring that can generate urging force due to displacement between an intermediate portion ma attached to the bearing holding member C and a peripheral portion mb 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] Further, the clutch member according to the present 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 can press the drive-side clutch plate 6 and the driven-side clutch plate 7 against each other by moving the second clutch member 4b when a rotational force is input to the first clutch member 4a via the output shaft 3 (output member), and a recess 4d is formed in the first clutch member 4a. Therefore, it is possible to avoid interference of the movement of the second clutch member 4b by the reverse torque transmission cam due to the bearing holding member C, and to enable smooth movement of each of the bearing holding member C and the second clutch member 4b by the reverse torque transmission cam.

[0168] With the above-described embodiment, the reverse torque transmission cam can move the second clutch member 4b in a direction toward the link member 9 to maintain contact between the link member 9 and the counterweight member 8. Therefore, 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 by the counterweight member 8 when engine brake is applied.

[0169] The reverse torque transmission cam according to the present 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 mating surfaces of the first clutch member 4a and the second clutch member 4b, respectively. Therefore, it is possible to enable reliable and smooth movement of the second clutch member 4b by the reverse torque transmission cam.

[0170] Further, the power transmission device includes a press-fitting assist cam constituted by an inclined surface 4aa of the first clutch member 4a and an inclined surface 5a of the pressure member 5 facing each other, and when the rotational force input to the input gear 1 (input member) becomes transmittable to the output shaft 3 (output member), the press-fitting assist cam increases the press-fitting force between the driving-side clutch plate 6 and the driven-side clutch plate 7. Thus, in addition to the press-fitting force generated by the movement of the weight member 8 by the centrifugal force, the press-fitting force generated by the press-fitting assist cam can be applied, and the driving-side clutch plate 6 and the driven-side clutch plate 7 can be more smoothly and reliably pressed against each other.

[0171] Further, the power transmission device includes a reverse torque limiter cam constituted by an inclined surface 4ab of the first clutch member 4a and an inclined surface 5b of the pressure member 5 facing each other, and 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 (first clutch member 4a) and the pressure member 5 rotate relative to each other, the reverse torque limiter cam can release the press-fitting force between the driving-side clutch plate 6 and the driven-side clutch plate 7. Thus, 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 actuated because the reverse torque transmission cam is actuated before the reverse torque limiter cam starts to work.

[0172] Further, the present embodiment includes a reverse torque transmission cam 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), and a torque transmission portion that 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). Thus, 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 of the wheel side to the engine side, and power transmission can be stably performed when the weight member 8 is moved to the radially outer position and the pressure member 5 is moved to the working position.

[0173] Further, the power transmission device includes a movement amount limiting portion that 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. Thus, the reverse torque transmission cam can be enabled to move the second clutch member 4b within a set range.

[0174] Furthermore, the protrusion F is formed in either the first clutch member 4a or the second clutch member 4b. The torque transmission part is composed of one side surface F1 of the protrusion F and a first contact surface G1 that receives rotational force by contacting the side surface F1. The movement limiting part is composed of another side surface F2 of the protrusion F and a second contact surface G2 that limits the movement by contacting the other side surface F2. Therefore, the protrusion F can simultaneously serve as both a torque transmission part and a movement limiting part.

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

[0176] Figure 25 One embodiment is shown in which the buffer member 12 is attached to the surface of the first clutch member 4a facing the second clutch member 4b. Figure 26 One embodiment is shown in which a buffer member 12 is attached to the surface of the stacked portion (disc assembly) of the drive-side clutch disc 6 and the driven-side clutch disc 7 that applies actuation force to the first clutch member 4a. The bearing retaining member C' is movable via the actuating member 10', and the release spring m' is composed of a helical spring attached to both the bearing retaining member C' and the pressure member 5.

[0177] Furthermore, instead of the buffer member 12 made of a conical disc spring, another elastic member can be used. For example, such as... Figure 27 As shown, the buffer member 12', which is composed of a wave spring, can be disposed in the receiving recess 4c. Figure 28 and Figure 29 As shown, the wave spring is composed of a C-shaped member having a cutout 12'a in a portion of the ring. The wave spring has a wave shape relative to the thickness direction t and can generate elastic force. The wave spring is positioned between the first clutch member 4a and the second clutch member 4b, and the wave spring can be compressed during the movement of the linkage member 9 and the pressure member 5 from the non-operating position to the operating position, thereby applying actuation force while allowing the linkage member 9 and the pressure member 5 to move.

[0178] In the power transmission device shown in the drawing, the bearing holding member C has a plurality of (three in the present embodiment) communication holes Cc formed in the side wall thereof, and allows oil supplied to the inside of the bearing holding member C to flow to the outside via the oil flow path r. The actuating member 10" engages with the roller bearing B1 of the bearing holding member C, and due to the operation of the driver or the work of the actuator, the actuating member 10" can move the pressure member 5 between the working position and the non-working position by moving in the left-right direction in the drawing.

[0179] As Figure 27 shown, the actuating member 10" according to the present embodiment is pull type. When operated by hand or an actuator, the actuating member 10" moves to the right in the drawing and pulls the bearing B1 in the same direction, and by this the actuating member 10" can release the pressure contact force between the driving side clutch plate 6 and the driven side clutch plate 7. As Figure 30 shown, a buffer member 12' composed of a coned disc spring can be used instead of the buffer member 12 of the power transmission device shown in Figure 27 .

[0180] In addition, as Figure 31 shown, a reverse torque transmission cam (cam surface K1 and cam surface T1) can be provided in the outer peripheral edge 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 edge 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 (thrust) of the second clutch member 4b can be set larger.

[0181] In Figure 31 the power transmission device shown in the drawing, no buffer member 12 or 12' is provided. However, a buffer member 12 composed of a coned disc spring can be provided radially inside the reverse torque transmission cam (cam surface K1 and cam surface T1) (see Figure 32 ), or a buffer member 12' composed of a wave spring can be provided radially inside the reverse torque transmission cam (cam surface K1 and cam surface T1) (see Figure 33 ).

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

[0183] Industrial applicability

[0184] The present application can be applied to power transmission devices having different outer shapes or having another additional function as long as the set load of the clutch spring is set to be smaller than the maximum load of the release spring.

Claims

1. A power transmitting apparatus comprising: a clutch member housed in a clutch case that rotates together with an input member that rotates by a driving force of an engine of a vehicle, and to which a plurality of driving-side clutch plates are attached, a plurality of driven-side clutch plates alternately formed with the driving-side clutch plates are attached to the clutch member, and the clutch member is coupled to an output member that can rotate a wheel of the vehicle; a pressure member that is movable in an axial direction of the output member between an operating position at which the pressure member is in a state of pressing the driving-side clutch plates and the driven-side clutch plates to be able to transmit the driving force of the engine to the wheel, and a non-operating position at which the pressure member releases a pressing force between the driving-side clutch plates and the driven-side clutch plates to be able to stop the transmission of the driving force of the engine to the wheel; a weight member that is movable from a radially inner side position to a radially outer side position due to a centrifugal force generated when the clutch case rotates; an actuating member that can move the pressure member in a direction in which the pressing force between the driving-side clutch plates and the driven-side clutch plates is released; a bearing that supports the actuating member; a bearing holding member that holds the bearing, is composed of a cylindrical member that is open at one end, and in a state in which the weight member is at the radially inner side position, an open end portion of the bearing holding member is fitted to the clutch member; a spring that exerts a force on the bearing holding member in a direction from the bearing holding member toward the clutch member, the weight member is configured to switch the driving-side clutch plates and the driven-side clutch plates from a non-operating state in which the pressing force is released to an operating state in which the driving-side clutch plates and the driven-side clutch plates are pressed against each other to be able to transmit the driving force of the engine to the wheel when the weight member moves from the radially inner side position to the radially outer side position, the pressure member is fitted to an outer peripheral surface of the bearing holding member, and is configured to move together with the bearing holding member and contact the pressure member to move the pressure member from the operating position to the non-operating position when the actuating member moves the pressure member in a direction in which the pressing force between the driving-side clutch plates and the driven-side clutch plates is released.

2. The power transmitting apparatus according to claim 1, wherein the bearing holding member holds the bearing at a top portion thereof on a side opposite to the opening in the axial direction of the output member, and a diameter of the opening is larger than a diameter of the top portion. ​

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