Clutch device

Abstract

To provide a clutch device excellent in assembling property of a clutch center with a pressure plate.SOLUTION: In a clutch device 10, when a pressure side top surface 90C and a center side top surface 60C are positioned in the same position relative to a direction D, and an end 84HB at a side in a second circumferential direction S2 of an insertion hole 84H and a boss part 54 are brought into contact with each other, an end 90AB in a first circumferential direction S1 of a pressure side assist cam surface 90A is positioned on a side in the first circumferential direction S1 with respect to an end 60AB in the second circumferential direction S2 of a center side assist cam surface 60A, an end 90SB in the first circumferential direction S1 of a pressure side slipper cam surface 90S is positioned on a side in the first circumferential direction S1 with respect to an end 60SB in the second circumferential direction S2 of a center side slipper cam surface 60S, and the formula of LB>LA and LC>LA, the formula of LD≥LE / 4 and the formula LF≥LG / 4 are satisfied.SELECTED DRAWING: Figure 12B

Description

[Technical field]

[0001] The present invention relates to a clutch device, and more particularly to a clutch device that selectively transmits or cuts off the rotational driving force of an input shaft, which is rotationally driven by a prime mover such as an engine, to an output shaft. [Background technology]

[0002] Conventionally, vehicles such as motorcycles are equipped with a clutch device. The clutch device is disposed between an engine and a driving wheel, and transmits or interrupts the rotational driving force of the engine to the driving wheel. The clutch device usually includes a plurality of input side rotating plates that rotate by the rotational driving force of the engine, and a plurality of output side rotating plates connected to an output shaft that transmits the rotational driving force to the driving wheel. The input side rotating plates and the output side rotating plates are arranged alternately in the stacking direction, and the transmission or interruption of the rotational driving force is performed by pressing the input side rotating plates and the output side rotating plates against each other and separating them.

[0003] For example, Patent Document 1 and Patent Document 2 disclose a clutch device including a clutch center and a pressure plate that is arranged so as to be able to approach and separate from the clutch center. The pressure plate is configured so as to be able to press an input side rotating plate and an output side rotating plate. In this way, the clutch device uses an assembled clutch center and pressure plate.

[0004] In addition, the clutch center and pressure plate of the clutch devices in Patent Documents 1 and 2 are equipped with an assist cam surface that generates a force in a direction that moves the pressure plate closer to the clutch center when the rotational driving force of the engine can be transmitted to the output shaft, thereby increasing the pressing force between the input side rotating plate and the output side rotating plate, and a slipper cam surface that moves the pressure plate away from the clutch center when the rotational speed of the clutch center exceeds the rotational speed of the pressure plate, thereby reducing the pressing force between the input side rotating plate and the output side rotating plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5847551 [Patent Document 2] International Publication No. 2018 / 172176 Summary of the Invention [Problem to be solved by the invention]

[0006] However, depending on the positions of the assist cam surface and slipper cam surface of the clutch center and the assist cam surface and slipper cam surface of the pressure plate, the cam surfaces of the two may interfere with each other when assembling the clutch center and the pressure plate, making assembly difficult.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a clutch device which is excellent in assembling ability between the clutch center and the pressure plate. [Means for solving the problem]

[0008] The clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input shaft to an output shaft, and includes a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotating plates that are rotationally driven by the rotational drive of the input shaft and that rotates together with the output shaft, and a pressure plate that is arranged to be able to approach or move away from the clutch center and to rotate relatively thereto, holds at least a portion of a plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and is able to press the input side rotating plates and the output side rotating plates, The clutch center includes an output shaft holding portion to which the output shaft is connected, a center-side assist cam surface that is located radially outward of the output shaft holding portion and that generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input side rotating plate and the output side rotating plate when the pressure plate rotates relative to the clutch center, a center-side slipper cam surface that moves the pressure plate away from the clutch center in order to reduce the pressing force between the input side rotating plate and the output side rotating plate, and the center-side assist cam surface. and a center side top surface located between the center side slipper cam surfaces, and a boss portion located radially outward from the output shaft holding portion and extending toward the pressure plate, wherein the pressure plate has a pressure side assist cam surface configured to be able to come into contact with the center side assist cam surface when the pressure plate rotates relative to the clutch center, and which generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input side rotating plate and the output side rotating plate, and a pressure-side slipper cam surface that is configured to be able to come into contact with the center-side slipper cam surface and that separates the pressure plate from the clutch center to reduce the pressing force between the input-side rotating plate and the output-side rotating plate, and a pressure-side top surface that is located between the pressure-side assist cam surface and the pressure-side slipper cam surface; a plurality of pressure-side cam portions each having a pressure-side top surface that is located between the pressure-side assist cam surface and the pressure-side slipper cam surface; a moving direction that is a direction in which the pressure plate approaches and moves away from the clutch center, a first direction that is a direction in which the pressure plate approaches the clutch center,a spring accommodating portion that is formed in the pressure-side cam portion so as to be recessed from the second direction to the first direction when a direction in which the pressure plate moves away from the clutch center is defined as a second direction, and that accommodates a pressure spring that urges the pressure plate in the first direction, and an insertion hole into which the boss portion is inserted is formed through the spring accommodating portion, and a direction from one pressure-side cam portion to the other pressure-side cam portion in a circumferential direction is defined as a first circumferential direction, and a direction from the other pressure-side cam portion to one pressure-side cam portion in a circumferential direction is defined as a second circumferential direction. When a direction toward a slipper-side cam portion is defined as a second circumferential direction, the pressure plate and the clutch center are configured to rotate in the first circumferential direction, and when the pressure-side top surface and the center-side top surface are located at the same position with respect to the moving direction and the second circumferential direction end of the insertion hole and the boss portion are in contact with each other, the first circumferential direction end of the pressure-side assist cam surface is located on the first circumferential direction side of the second circumferential direction end of the center-side assist cam surface, and The circumferential end is located on the first circumferential side of the second circumferential end of the center-side slipper cam surface, and when the circumferential length from the first circumferential end of the pressure-side assist cam surface to the second circumferential end of the center-side assist cam surface is defined as LA, the circumferential length from the first circumferential end of the insertion hole to the boss portion is defined as LB, and the circumferential length from the first circumferential end of the pressure-side slipper cam surface to the second circumferential end of the center-side slipper cam surface is defined as LC, then LB>LA and L where LD is a length in the movement direction from a point where a straight line that is parallel to the movement direction and passes through the second circumferential end of the center-side assist cam surface intersects with the pressure-side assist cam surface to the pressure-side top surface, and LE is a length in the movement direction of the pressure-side assist cam surface, LF is a length in the movement direction from a point where a straight line that is parallel to the movement direction and passes through the first circumferential end of the pressure-side assist cam surface intersects with the center-side assist cam surface to the center-side top surface, and LD is a length in the movement direction of the pressure-side assist cam surface, LE is a length in the movement direction of the pressure-side assist cam surface, LF is a length in the movement direction from a point where a straight line that is parallel to the movement direction and passes through the first circumferential end of the pressure-side assist cam surface intersects with the center-side assist cam surface to the center-side top surface,When the length of the center side assist cam surface in the moving direction is LG, the formula LF≧LG / 4 is satisfied.

[0009] According to the clutch device of the present invention, when the pressure-side top surface and the center-side top surface are located at the same position in the moving direction and the second circumferential end of the insertion hole is in contact with the boss portion, the first circumferential end of the pressure-side assist cam surface is located on the first circumferential side of the second circumferential end of the center-side assist cam surface, and the first circumferential end of the pressure-side slipper cam surface is located on the first circumferential side of the second circumferential end of the center-side slipper cam surface. According to the above aspect, when the clutch center and the pressure plate are assembled, even if the pressure plate is brought close to the clutch center with force, the pressure-side top surface and the center-side top surface come into contact with each other first. That is, since the pressure-side slipper cam surface and the center-side slipper cam surface do not come into contact with each other first, it is possible to prevent the center-side slipper cam surface from being damaged by the first circumferential end of the pressure-side slipper cam surface. Moreover, when the pressure-side top surface and the center-side top surface are located at the same position in the moving direction and the second circumferential end of the insertion hole and the boss portion are in contact with each other, the formulas LB>LA and LC>LA are satisfied. According to the above aspect, the pressure plate can be assembled to the clutch center by rotating the pressure plate in the second circumferential direction. Furthermore, when the pressure-side top surface and the center-side top surface are located at the same position in the moving direction and the second circumferential end of the insertion hole and the boss portion are in contact with each other, the formulas LD≧LE / 4 and LF≧LG / 4 are satisfied. If the overlapping portion between the pressure-side top surface and the center-side top surface in the circumferential direction S is small when the pressure-side top surface and the center-side top surface come into contact with each other, there is a risk that the pressure-side assist cam surface and the center-side assist cam surface will be damaged. However, since the equation LD≧LE / 4 is satisfied and the equation LF≧LG / 4 is satisfied, a sufficient overlapping area between the pressure side top surface and the center side top surface is secured, thereby suppressing damage to the pressure side assist cam surface and the center side assist cam surface. Effect of the Invention

[0010] According to the present invention, it is possible to provide a clutch device which is excellent in assembling properties between the clutch center and the pressure plate. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a clutch device according to one embodiment. [Diagram 2] FIG. 2 is a perspective view of the clutch center according to one embodiment. [Diagram 3] FIG. 3 is a plan view of the clutch center according to one embodiment. [Figure 4] FIG. 4 is a perspective view of a pressure plate according to one embodiment. [Diagram 5] FIG. 5 is a plan view of a pressure plate according to one embodiment. [Figure 6] FIG. 6 is a perspective view of a pressure plate according to one embodiment. [Figure 7] FIG. 7 is a plan view of a pressure plate according to one embodiment. [Figure 8] FIG. 8 is an enlarged side view of a part of the pressure-side cam portion according to one embodiment. [Figure 9] FIG. 9 is an enlarged perspective view of a portion of a pressure plate according to one embodiment. [Figure 10] FIG. 10 is a plan view showing a state in which the clutch center and the pressure plate according to one embodiment are combined. [Figure 11A] FIG. 11A is a schematic diagram for explaining the action of the center side assist cam surface and the pressure side assist cam surface. [Figure 11B] FIG. 11B is a schematic diagram for explaining the action of the center-side slipper cam surface and the pressure-side slipper cam surface. [Figure 12A] FIG. 12A is an enlarged cross-sectional view of a portion of the pressure plate and the clutch center according to one embodiment. [Figure 12B]FIG. 12B is an enlarged cross-sectional view of a portion of the pressure plate and the clutch center when the pressure-side top surface and the center-side top surface come into contact with each other according to one embodiment. [Figure 12C] FIG. 12C is an enlarged cross-sectional view showing a portion of FIG. 12B. [Figure 13] FIG. 13 is an enlarged cross-sectional view of a portion of a pressure plate and a clutch center according to another embodiment. [Figure 14] FIG. 14 is an exploded perspective view of a clutch center and a pressure plate according to another embodiment. [Figure 15] FIG. 15 is a perspective view of a pressure plate according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a clutch device according to the present invention will be described with reference to the drawings. Note that the embodiment described here is not intended to limit the present invention in any particular way. In addition, the same reference numerals are used for members and parts that perform the same functions, and duplicated descriptions will be omitted or simplified as appropriate.

[0013] First Embodiment Fig. 1 is a cross-sectional view of a clutch device 10 according to a first embodiment. The clutch device 10 is provided on a vehicle such as a motorcycle. The clutch device 10 is a device that transmits or cuts off the rotational driving force of an input shaft (crankshaft) of an engine of the motorcycle to an output shaft 15. The clutch device 10 is a device that transmits or cuts off the rotational driving force of the input shaft to a driving wheel (rear wheel) via the output shaft 15. The clutch device 10 is disposed between the engine and the transmission.

[0014] In the following description, the direction in which the pressure plate 70 of the clutch device 10 approaches and moves away from the clutch center 40 is referred to as direction D (one example of a moving direction), the direction in which the pressure plate 70 approaches the clutch center 40 is referred to as a first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is referred to as a second direction D2. The circumferential direction of the clutch center 40 and the pressure plate 70 is referred to as a circumferential direction S, the direction from one pressure side cam portion 90 to the other pressure side cam portion 90 in the circumferential direction S is referred to as a first circumferential direction S1 (see FIG. 5), and the direction from the other pressure side cam portion 90 to one pressure side cam portion 90 is referred to as a second circumferential direction S2 (see FIG. 5). In this embodiment, the axial direction of the output shaft 15, the axial direction of the clutch housing 30, the axial direction of the clutch center 40, and the axial direction of the pressure plate 70 are the same as the direction D. Furthermore, the pressure plate 70 and the clutch center 40 rotate in a first circumferential direction S1. However, the above direction is merely a direction determined for the convenience of explanation, and does not limit the installation mode of the clutch device 10 or the present invention in any way.

[0015] As shown in FIG. 1, the clutch device 10 includes an output shaft 15, an input side rotating plate 20, an output side rotating plate 22, a clutch housing 30, a clutch center 40, a pressure plate 70, and a stopper plate 100.

[0016] As shown in Fig. 1, the output shaft 15 is a shaft body formed into a hollow shape. One end of the output shaft 15 rotatably supports an input gear 35 and a clutch housing 30 (described later) via a needle bearing 15A. The output shaft 15 fixedly supports a clutch center 40 via a nut 15B. That is, the output shaft 15 rotates integrally with the clutch center 40. The other end of the output shaft 15 is connected to, for example, a transmission (not shown) of a motorcycle.

[0017] As shown in FIG. 1, the output shaft 15 includes a push rod 16A in a hollow portion 15H thereof and a push member 16B provided adjacent to the push rod 16A. The hollow portion 15H functions as a flow passage for clutch oil. The clutch oil flows inside the output shaft 15, i.e., inside the hollow portion 15H. The push rod 16A and the push member 16B are provided slidably inside the hollow portion 15H of the output shaft 15. One end (the end on the left side in the figure) of the push rod 16A is connected to a clutch operation lever (not shown) of the motorcycle, and slides inside the hollow portion 15H by operating the clutch operation lever to press the push member 16B in the second direction D2. A part of the push member 16B protrudes outward from the output shaft 15 (here, in the second direction D2) and is connected to a release bearing 18 provided on the pressure plate 70. The push rod 16A and the push member 16B are formed to have a smaller inner diameter than the inner diameter of the hollow portion 15H, ensuring the flow of clutch oil within the hollow portion 15H.

[0018] The clutch housing 30 is made of an aluminum alloy. The clutch housing 30 is formed in a cylindrical shape with a bottom. As shown in Fig. 1, the clutch housing 30 has a bottom wall 31 formed in a substantially circular shape, and a side wall 33 extending in a second direction D2 from an edge of the bottom wall 31. The clutch housing 30 holds a plurality of input side rotating plates 20.

[0019] As shown in Fig. 1, an input gear 35 is provided on a bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by a rivet 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates by the rotational drive of the input shaft of the engine. The input gear 35 is rotated integrally with the clutch housing 30 independently of the output shaft 15.

[0020] The input side rotating plate 20 is rotationally driven by the rotational drive of the input shaft. As shown in Fig. 1, the input side rotating plate 20 is held on the inner circumferential surface of a side wall 33 of the clutch housing 30. The input side rotating plate 20 is held in the clutch housing 30 by spline fitting. The input side rotating plate 20 is provided so as to be displaceable along the axial direction of the clutch housing 30. The input side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0021] The input side rotating plate 20 is a member pressed against the output side rotating plate 22. The input side rotating plate 20 is a flat plate formed in an annular shape. The input side rotating plate 20 is formed by punching out a thin plate made of SPCC (cold rolled steel plate) material into an annular shape. Friction materials (not shown) made of multiple pieces of paper are attached to the front and back surfaces of the input side rotating plate 20. Grooves several μm to several tens of μm deep are formed between the friction materials to hold clutch oil.

[0022] As shown in FIG. 1, the clutch center 40 is accommodated in the clutch housing 30. The clutch center 40 is arranged concentrically with the clutch housing 30. The clutch center 40 is made of an aluminum alloy. The clutch center 40 has a cylindrical main body 42 and a flange 68 extending radially outward from the outer circumferential edge of the main body 42. The clutch center 40 holds at least a part of the input side rotating plate 20 and the multiple output side rotating plates 22 arranged alternately in the direction D. The clutch center 40 is driven to rotate together with the output shaft 15.

[0023] As shown in FIG. 2, the main body 42 includes an annular base wall 43, an outer peripheral wall 45 located radially outward from the base wall 43 and extending toward the second direction D2, an output shaft holding portion 50 provided in the center of the base wall 43, a plurality of center side cam portions 60 connected to the base wall 43 and the outer peripheral wall 45, and a center side fitting portion 58.

[0024] The output shaft holding portion 50 is formed in a cylindrical shape. An insertion hole 51 into which the output shaft 15 is inserted and spline-fitted is formed in the output shaft holding portion 50. The insertion hole 51 is formed penetrating the base wall 43. An inner circumferential surface 50A of the output shaft holding portion 50 that forms the insertion hole 51 has a plurality of spline grooves formed along the axial direction. The output shaft 15 is connected to the output shaft holding portion 50.

[0025] As shown in FIG. 2, the outer peripheral wall 45 of the clutch center 40 is disposed radially outward from the output shaft holding portion 50. A spline fitting portion 46 is provided on the outer peripheral surface of the outer peripheral wall 45. The spline fitting portion 46 has a plurality of center side fitting teeth 47 extending in the axial direction of the clutch center 40 along the outer peripheral surface of the outer peripheral wall 45, a plurality of spline grooves 48 formed between adjacent center side fitting teeth 47 and extending in the axial direction of the clutch center 40, and an oil discharge hole 49. The center side fitting teeth 47 hold the output side rotating plate 22. The center side fitting teeth 47 are arranged in the circumferential direction S. The center side fitting teeth 47 are formed at equal intervals in the circumferential direction S. The center side fitting teeth 47 are formed in the same shape. The center side fitting teeth 47 protrude radially outward from the outer peripheral surface of the outer peripheral wall 45. The oil discharge hole 49 is formed penetrating the outer peripheral wall 45 in the radial direction. The oil discharge hole 49 is formed between the adjacent center side fitting teeth 47. That is, the oil discharge hole 49 is formed in the spline groove 48. The oil discharge hole 49 is formed on the side of the center side cam portion 60. The oil discharge hole 49 is formed on the side of the center side slipper cam surface 60S of the center side cam portion 60. The oil discharge hole 49 is formed on the second circumferential direction S2 side of the center side slipper cam surface 60S. The oil discharge hole 49 is formed on the first circumferential direction S1 side of the boss portion 54 described later. In this embodiment, the oil discharge holes 49 are formed in threes at three positions in the circumferential direction S of the outer peripheral wall 45. The oil discharge holes 49 are arranged at equal intervals in the circumferential direction S. The oil discharge holes 49 communicate the inside and the outside of the clutch center 40. The oil drain hole 49 is a hole for draining the clutch oil that has flowed out from the output shaft 15 into the clutch center 40 to the outside of the clutch center 40 .

[0026] The output side rotating plate 22 is held by the spline fitting portion 46 of the clutch center 40 and the pressure plate 70. A part of the output side rotating plate 22 is held by the center side fitting teeth 47 and the spline grooves 48 of the clutch center 40 through spline fitting. Another part of the output side rotating plate 22 is held by pressure side fitting teeth 77 (see FIG. 4 ) of the pressure plate 70, which will be described later. The output side rotating plate 22 is provided so as to be displaceable along the axial direction of the clutch center 40. The output side rotating plate 22 is provided so as to be rotatable integrally with the clutch center 40.

[0027] The output side rotating plate 22 is a member pressed against the input side rotating plate 20. The output side rotating plate 22 is a flat plate formed in an annular shape. The output side rotating plate 22 is formed by punching out a thin plate material made of SPCC material into an annular shape. Grooves having a depth of several μm to several tens of μm are formed on the front and back surfaces of the output side rotating plate 22 for holding clutch oil. The front and back surfaces of the output side rotating plate 22 are each subjected to a surface hardening treatment in order to improve wear resistance. The friction material provided on the input side rotating plate 20 may be provided on the output side rotating plate 22 instead of the input side rotating plate 20, or may be provided on both the input side rotating plate 20 and the output side rotating plate 22.

[0028] The center cam portion 60 is formed in a platform shape having a cam surface made of an inclined surface constituting an Assist & Slipper (registered trademark) mechanism that generates an assist torque, which is a force that increases the pressing force (pressure contact force) between the input side rotating plate 20 and the output side rotating plate 22, or a slipper torque, which is a force that causes the input side rotating plate 20 and the output side rotating plate 22 to separate early and transition to a half-clutch state. The center cam portion 60 is formed so as to protrude from the base wall 43 in the second direction D2. As shown in FIG. 3, the center cam portions 60 are disposed at equal intervals in the circumferential direction S of the clutch center 40. In this embodiment, the clutch center 40 has three center cam portions 60, but the number of center cam portions 60 is not limited to three.

[0029] As shown in FIG. 3, the center-side cam portion 60 is located radially outward of the output shaft holding portion 50. The center-side cam portion 60 has a center-side assist cam surface 60A, a center-side slipper cam surface 60S, and a center-side top surface 60C. The center-side assist cam surface 60A is configured to generate a force in a direction that moves the pressure plate 70 closer to the clutch center 40 in order to increase the pressing force (pressing force) between the input side rotating plate 20 and the output side rotating plate 22 when rotating relative to the pressure plate 70. In this embodiment, when the above force is generated, the position of the pressure plate 70 relative to the clutch center 40 does not change, and the pressure plate 70 does not need to physically approach the clutch center 40. Note that the pressure plate 70 may be physically displaced relative to the clutch center 40. The center-side slipper cam surface 60S is configured to move the pressure plate 70 away from the clutch center 40 in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22 when rotating relative to the pressure plate 70. In the center-side cam parts 60 adjacent to each other in the circumferential direction S, the center-side assist cam surface 60A of one center-side cam part 60L and the center-side slipper cam surface 60S of the other center-side cam part 60M are arranged opposite each other in the circumferential direction S. The center-side top surface 60C is located between the center-side assist cam surface 60A and the center-side slipper cam surface 60S. More specifically, the center-side top surface 60C is located between the center-side assist cam surface 60A and the center-side slipper cam surface 60S in the circumferential direction S. The center-side top surface 60C is continuous with the center-side assist cam surface 60A and the center-side slipper cam surface 60S. The connection portion between the center side top surface 60C and the center side assist cam surface 60A, and the connection portion between the center side top surface 60C and the center side slipper cam surface 60S are curved surfaces.

[0030] As shown in FIG. 2, the clutch center 40 has a plurality of boss portions 54 (three in this embodiment). The boss portions 54 are members that support the pressure plate 70. The plurality of boss portions 54 are disposed at equal intervals in the circumferential direction S. The boss portions 54 are formed in a cylindrical shape. The boss portions 54 are located radially outward from the output shaft holding portion 50. The boss portions 54 extend toward the pressure plate 70 (i.e., toward the second direction D2). The boss portions 54 are provided on the base wall 43. The boss portions 54 are formed with a screw hole 54H into which the bolt 28 (see FIG. 1) is inserted. The screw hole 54H extends in the axial direction of the clutch center 40. The screw hole 54H is a hole for attaching the stopper plate 100.

[0031] As shown in FIG. 2, the center-side fitting portion 58 is located radially outward from the output shaft holding portion 50. The center-side fitting portion 58 is located radially outward from the center-side cam portion 60. The center-side fitting portion 58 is located on the second direction D2 side from the center-side cam portion 60. The center-side fitting portion 58 is formed on the inner peripheral surface of the outer peripheral wall 45. The center-side fitting portion 58 is configured to be slidably fitted onto a pressure-side fitting portion 88 (see FIG. 4) described later. The inner diameter of the center-side fitting portion 58 is formed with a fitting tolerance that allows the clutch oil flowing out from the tip portion 15T of the output shaft 15 to flow with respect to the pressure-side fitting portion 88. That is, a gap is formed between the center-side fitting portion 58 and the pressure-side fitting portion 88 described later. In this embodiment, for example, the center side fitting portion 58 is formed with an inner diameter that is 0.1 mm larger than the outer diameter of the pressure side fitting portion 88. The dimensional tolerance between the inner diameter of the center side fitting portion 58 and the outer diameter of the pressure side fitting portion 88 is appropriately set according to the amount of clutch oil to be circulated, and is, for example, not less than 0.1 mm and not more than 0.5 mm.

[0032] 2 and 3, the clutch center 40 has a center-side cam hole 43H penetrating a portion of the base wall 43. The center-side cam hole 43H extends from the side of the output shaft holding portion 50 to the outer peripheral wall 45. The center-side cam hole 43H is formed between the center-side assist cam surface 60A of the center-side cam portion 60 and the boss portion 54. When viewed from the axial direction of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap with each other.

[0033] As shown in FIG. 1, the pressure plate 70 is provided so as to be capable of approaching or separating from the clutch center 40 and rotatable relative thereto. The pressure plate 70 is configured so as to be capable of pressing the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 70 is arranged concentrically with the clutch center 40 and the clutch housing 30. The pressure plate 70 is formed of an aluminum alloy. The pressure plate 70 has a main body 72 and a flange 98 that is connected to the outer circumferential edge of the main body 72 on the second direction D2 side and extends radially outward. The main body 72 protrudes in the first direction D1 beyond the flange 98. The pressure plate 70 holds at least a portion of the input side rotating plate 20 and the multiple output side rotating plates 22 that are arranged alternately.

[0034] As shown in FIG. 4, the main body 72 includes a cylindrical portion 80, a plurality of pressure-side cam portions 90, a pressure-side fitting portion 88, and a spring accommodating portion 84 (see also FIG. 6).

[0035] The cylindrical portion 80 is formed in a cylindrical shape. The cylindrical portion 80 is formed integrally with the pressure side cam portion 90. The cylindrical portion 80 accommodates the tip portion 15T (see FIG. 1) of the output shaft 15. The cylindrical portion 80 accommodates the release bearing 18 (see FIG. 1). The cylindrical portion 80 is a portion that receives a pressing force from the push member 16B. The cylindrical portion 80 is a portion that receives the clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0036] The pressure-side cam portion 90 is formed in a platform shape having a cam surface made of an inclined surface constituting an Assist & Slipper (registered trademark) mechanism that slides on the center-side cam portion 60 to generate an assist torque or a slipper torque. The pressure-side cam portion 90 is formed so as to protrude in a first direction D1 beyond the flange 98. As shown in FIG. 5, the pressure-side cam portions 90 are disposed at equal intervals in the circumferential direction S of the pressure plate 70. In this embodiment, the pressure plate 70 has three pressure-side cam portions 90, but the number of pressure-side cam portions 90 is not limited to three.

[0037] As shown in FIG. 5, the pressure-side cam portion 90 is located radially outward from the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also FIG. 7 and FIG. 9), a pressure-side slipper cam surface 90S, and a pressure-side top surface 90C. The pressure-side assist cam surface 90A is configured to be able to come into contact with the center-side assist cam surface 60A. The pressure-side assist cam surface 90A is configured to generate a force in a direction that moves the pressure plate 70 closer to the clutch center 40 in order to increase the pressing force (pressing force) between the input-side rotating plate 20 and the output-side rotating plate 22 when rotating relative to the clutch center 40. The pressure-side slipper cam surface 90S is configured to be able to come into contact with the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to move the pressure plate 70 away from the clutch center 40 in order to reduce the pressing force (pressing force) between the input side rotating plate 20 and the output side rotating plate 22 when rotating relative to the clutch center 40. In the pressure-side cam portions 90 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 90M are disposed opposite each other in the circumferential direction S. The pressure-side top surface 90C is located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S. More specifically, the pressure-side top surface 90C is located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S in the circumferential direction S. The pressure side top surface 90C is continuous with the pressure side assist cam surface 90A and the pressure side slipper cam surface 90S. The connecting portion between the pressure side top surface 90C and the pressure side assist cam surface 90A and the connecting portion between the pressure side top surface 90C and the pressure side slipper cam surface 90S are curved surfaces. Here, the pressure side assist cam surface 90A, the pressure side slipper cam surface 90S, the center side assist cam surface 60A, and the center side slipper cam surface 60S are parallel to each other.

[0038] As shown in Fig. 8, a chamfered portion 90AP is formed by linearly chamfering an end portion in the circumferential direction S of the pressure-side assist cam surface 90A of the pressure-side cam portion 90. The corner of the chamfered portion 90AP (the corner on the first direction D1 and first circumferential direction S1 side) is a right angle. More specifically, the chamfered portion 90AP is formed at an end portion 90AB in the first circumferential direction S1 of the pressure-side assist cam surface 90A.

[0039] Here, the action of the center side cam portion 60 and the pressure side cam portion 90 will be described. When the engine speed increases and the rotational driving force input to the input gear 35 and the clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, a rotational force in the first circumferential direction S1 is applied to the pressure plate 70 as shown in Fig. 11A. Therefore, a force in the first direction D1 is generated on the pressure plate 70 due to the action of the center side assist cam surface 60A and the pressure side assist cam surface 90A. This increases the pressing force between the input side rotating plate 20 and the output side rotating plate 22.

[0040] On the other hand, when the rotation speed of the output shaft 15 exceeds the rotation speed of the input gear 35 and the clutch housing 30 and back torque is generated, a rotational force in the first circumferential direction S1 is applied to the clutch center 40 as shown in Fig. 11B. Therefore, the action of the center side slipper cam surface 60S and the pressure side slipper cam surface 90S moves the pressure plate 70 in the second direction D2 to release the pressure contact force between the input side rotating plate 20 and the output side rotating plate 22. This makes it possible to avoid malfunctions of the engine and transmission due to back torque.

[0041] 4, the pressure-side fitting portion 88 is located radially outward from the pressure-side cam portion 90. The pressure-side fitting portion 88 is located on the second direction D2 side from the pressure-side cam portion 90. The pressure-side fitting portion 88 is configured to be slidably fitted into the center-side fitting portion 58 (see FIG. 2).

[0042] As shown in Figs. 4 and 5, the pressure plate 70 has a pressure-side cam hole 73H penetrating a part of the main body 72 and the flange 98. The pressure-side cam hole 73H is located radially outward from the cylindrical portion 80. The pressure-side cam hole 73H extends from the side of the cylindrical portion 80 to a position radially outward from the pressure-side fitting portion 88. The pressure-side cam hole 73H is formed between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of the adjacent pressure-side cam portion 90. As shown in Figs. 5 and 7, when viewed from the axial direction of the pressure plate 70, the pressure-side assist cam surface 90A and a part of the pressure-side cam hole 73H overlap each other.

[0043] As shown in FIG. 4, the pressure plate 70 has a plurality of pressure side fitting teeth 77 arranged on a flange 98. The pressure side fitting teeth 77 hold the output side rotating plate 22. The pressure side fitting teeth 77 protrude from the flange 98 in a first direction D1. The pressure side fitting teeth 77 are located radially outward from the cylindrical portion 80. They are located radially outward from the pressure side cam portion 90. The pressure side fitting teeth 77 are located radially outward from the pressure side cam portion 90. The pressure side fitting teeth 77 are located radially outward from the pressure side fitting portion 88. The pressure side fitting teeth 77 are aligned in the circumferential direction S. The pressure side fitting teeth 77 are arranged at equal intervals in the circumferential direction S. In this embodiment, since some of the pressure side fitting teeth 77 are removed, the intervals in those portions are wider, but the remaining adjacent pressure side fitting teeth 77 are disposed at equal intervals.

[0044] As shown in FIG. 6 and FIG. 7, the spring accommodating portion 84 is formed in the pressure side cam portion 90. The spring accommodating portion 84 is formed so as to be recessed from the second direction D2 to the first direction D1. The spring accommodating portion 84 is formed in an elliptical shape. The spring accommodating portion 84 accommodates the pressure spring 25 (see FIG. 1). The spring accommodating portion 84 is formed with an insertion hole 84H through which the boss portion 54 (see FIG. 2) is inserted. That is, the insertion hole 84H is formed through the pressure side cam portion 90. The insertion hole 84H is formed in an elliptical shape. The insertion hole 84H is located on the second circumferential direction S2 side of the pressure side assist cam surface 90A. The insertion hole 84H is located on the first circumferential direction S1 side of the pressure side slipper cam surface 90S.

[0045] 1, the pressure spring 25 is accommodated in the spring accommodating portion 84. The pressure spring 25 fits onto the boss portion 54 inserted into the insertion hole 84H of the spring accommodating portion 84. The pressure spring 25 biases the pressure plate 70 toward the clutch center 40 (i.e., toward the first direction D1). The pressure spring 25 is, for example, a coil spring formed by winding spring steel in a spiral shape.

[0046] Fig. 10 is a plan view showing the state in which the clutch center 40 and the pressure plate 70 are assembled. In the state shown in Fig. 10, the pressure side assist cam surface 90A and the center side assist cam surface 60A are not in contact with each other, and the pressure side slipper cam surface 90S and the center side slipper cam surface 60S are not in contact with each other. At this time, the pressure plate 70 is closest to the clutch center 40. As shown in FIG. 10, in the entire range in the circumferential direction S from the position just before the pressure side slipper cam surface 90S and the center side slipper cam surface 60S come into contact to the position just before the pressure side assist cam surface 90A and the center side assist cam surface 60A come into contact, the distance L5 in the circumferential direction S between the boss portion 54 and the end 84HA on the pressure side assist cam surface 90A side (i.e., the first circumferential direction S1 side) of the insertion hole 84H is longer than the distance L6 in the circumferential direction S between the boss portion 54 and the end 84HB on the pressure side slipper cam surface 90S side (i.e., the second circumferential direction S2 side) of the insertion hole 84H. When the pressure plate 70 is closest to the clutch center 40, the pressure side slipper cam surface 90S and the center side slipper cam surface 60S do not contact each other, and the pressure side assist cam surface 90A and the center side assist cam surface 60A do not contact each other, the distance L5 is always longer than the distance L6. Here, the entire range in the circumferential direction S from the position immediately before the pressure side slipper cam surface 90S and the center side slipper cam surface 60S come into contact with each other to the position immediately before the pressure side assist cam surface 90A and the center side assist cam surface 60A come into contact with each other is the range in the circumferential direction S from the position where the pressure side slipper cam surface 90S and the center side slipper cam surface 60S come into contact with each other to the position where the pressure side assist cam surface 90A and the center side assist cam surface 60A come into contact with each other, excluding the position where the pressure side slipper cam surface 90S and the center side slipper cam surface 60S come into contact with each other and the position where the pressure side assist cam surface 90A and the center side assist cam surface 60A come into contact with each other.

[0047] FIG. 12A is a cross-sectional view of an enlarged portion of the pressure plate 70 and the clutch center 40. FIG. 12A is a cross-sectional view taken along the line XIIA-XIIA in FIG. 10. That is, FIG. 12A is a cross-sectional view taken along a plane passing through the axis 54C of the boss portion 54 and extending in the circumferential direction S and the axial direction of the output shaft 15. As shown in FIG. 12A, in a state in which the center-side top surface 60C and the pressure-side top surface 90C are located at the same position with respect to the direction D and the end 60AB of the center-side assist cam surface 60A in the second circumferential direction S2 faces the end 90AB of the pressure-side assist cam surface 90A in the first circumferential direction S1, the end 90SB of the pressure-side slipper cam surface 90S in the first circumferential direction S1 is located closer to the first circumferential direction S1 than the end 60SB of the center-side slipper cam surface 60S in the second circumferential direction S2. With respect to the circumferential direction S, a gap is formed between the end 60SB and the end 90SB. When the center-side top surface 60C and the pressure-side top surface 90C are located at the same position in the moving direction D and the end 84HA of the insertion hole 84H on the pressure-side assist cam surface 90A side is in contact with the boss portion 54, the end 60AB in the second circumferential direction S2 of the center-side assist cam surface 60A is located closer to the first circumferential direction S1 than the end 90AB in the first circumferential direction S1 of the pressure-side assist cam surface 90A. A gap is formed between the end 60AB and the end 90AB in the circumferential direction S. The center-side top surface 60C and the pressure-side top surface 90C being located at the same position in the direction D means a position where the center-side top surface 60C and the pressure-side top surface 90C are in contact with each other when the center-side top surface 60C and the pressure-side top surface 90C are located at the same position in the circumferential direction S.

[0048] As shown in FIG. 12B, when the clutch center 40 and the pressure plate 70 are assembled, the boss portion 54 is inserted into the insertion hole 84H, and the center side top surface 60C and the pressure side top surface 90C are brought into contact with each other in the direction D (for example, into surface contact). When the pressure side top surface 90C and the center side top surface 60C are located at the same position with respect to direction D, and the end 84HB on the second circumferential direction S2 side of the insertion hole 84H (i.e., the pressure side slipper cam surface 90S side) is in contact with the boss portion 54, the end 90AB in the first circumferential direction S1 of the pressure side assist cam surface 90A is located closer to the first circumferential direction S1 than the end 60AB in the second circumferential direction S2 of the center side assist cam surface 60A, and the end 90SB in the first circumferential direction S1 of the pressure side slipper cam surface 90S is located closer to the first circumferential direction S1 than the end 60SB in the second circumferential direction S2 of the center side slipper cam surface 60S. In this way, when assembling the clutch center 40 and the pressure plate 70, the boss portion 54 can be inserted into the insertion hole 84H so that the end portion 84HB on the second circumferential direction S2 side of the insertion hole 84H is in contact with the boss portion 54, thereby enabling the pressure side top surface 90C to come into contact with the center side top surface 60C. This prevents the end portion 90SB of the pressure side slipper cam surface 90S in the first circumferential direction S1 from colliding forcefully with the center side slipper cam surface 60S, thereby preventing damage to the center side slipper cam surface 60S.

[0049] Furthermore, as shown in FIG. 12B, when the pressure-side top surface 90C and the center-side top surface 60C are located at the same position in the direction D, and the end 84HB on the second circumferential direction S2 side of the insertion hole 84H (i.e., the pressure-side slipper cam surface 90S side) is in contact with the boss portion 54, the length in the circumferential direction S from the end 90AB in the first circumferential direction S1 of the pressure-side assist cam surface 90A to the end 60AB in the second circumferential direction S2 of the center-side assist cam surface 60A is LA, the length in the circumferential direction S from the end 84HA on the first circumferential direction S1 side of the insertion hole 84H (i.e., the pressure-side assist cam surface 90A side) to the boss portion 54 is LB, and the length in the circumferential direction S from the end 90SB in the first circumferential direction S1 of the pressure-side slipper cam surface 90S to the end 60SB in the second circumferential direction S2 of the center-side slipper cam surface 60S is LC, the equations LB>LA and LC>LA are satisfied. As a result, by rotating the pressure plate 70 in the second circumferential direction S2 (see Figure 12A), the pressure plate 70 can be assembled to the clutch center 40 without interference between the pressure side assist cam surface 90A and the center side assist cam surface 60A, and without interference between the pressure side slipper cam surface 90S and the center side slipper cam surface 60S.

[0050] Furthermore, as shown in FIG. 12C, in a state where the pressure-side top surface 90C and the center-side top surface 60C are located at the same position in the direction D and the end 84HB on the second circumferential direction S2 side of the insertion hole 84H (i.e., the pressure-side slipper cam surface 90S side) is in contact with the boss portion 54, the length in the direction D from a point Q1 where a straight line P1 that is parallel to the direction D and passes through the end 60AB of the center-side assist cam surface 60A in the second circumferential direction S2 intersects with the pressure-side assist cam surface 90A to the pressure-side top surface 90C is defined as LD. When the length of the pressure-side assist cam surface 90A in direction D is LE, the formula LD ≧ LE / 4 (preferably LD ≧ LE / 2) is satisfied, and when the length of the direction D from point Q2 where a straight line P2 that is parallel to direction D and passes through an end 90AB of the pressure-side assist cam surface 90A in the first circumferential direction S1 intersects with the center-side assist cam surface 60A to the center-side top surface 60C is LF, and when the length of the center-side assist cam surface 60A in direction D is LG, the formula LF ≧ LG / 4 (preferably LF ≧ LG / 2) is satisfied. As a result, when the center-side top surface 60C and the pressure-side top surface 90C are brought into contact with each other in the direction D, a wider range of contact can be achieved, thereby suppressing damage to the pressure-side assist cam surface 90A and the center-side assist cam surface 60A.

[0051] As shown in FIG. 1, the stopper plate 100 is provided so as to be able to come into contact with the pressure plate 70. The stopper plate 100 is a member that prevents the pressure plate 70 from moving away from the clutch center 40 in the second direction D2 by more than a predetermined distance. The stopper plate 100 is fixed to the boss portion 54 of the clutch center 40 by the bolt 28. The pressure plate 70 is fixed by tightening the bolt 28 to the boss portion 54 via the stopper plate 100 in a state in which the boss portion 54 of the clutch center 40 and the pressure spring 25 are arranged in the spring accommodating portion 84. The bolt 28 is inserted into the screw hole 54H of the boss portion 54. The stopper plate 100 is formed in a substantially triangular shape in a plan view. When the input side rotating plate 20 and the output side rotating plate 22 are assembled and the stopper plate 100 is attached to the boss portion 54, the pressure side top surface 90C is located closer to the first direction D1 than the center side top surface 60C (see FIG. 1).

[0052] Here, when the pressure plate 70 contacts the stopper plate 100, the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S are in contact with each other over 50% to 90% of the area of ​​the pressure-side slipper cam surface 90S and over 50% to 90% of the area of ​​the center-side slipper cam surface 60S, respectively. Also, when the pressure plate 70 contacts the stopper plate 100, the pressure spring 25 is separated from the side wall of the spring accommodating portion 84. That is, the pressure spring 25 is not sandwiched between the boss portion 54 and the spring accommodating portion 84, and excessive stress is prevented from being applied to the boss portion 54.

[0053] Here, the circumferential length L1 (see Figure 5) from the end 90AB in the first circumferential direction S1 of the pressure side assist cam surface 90A located on the first circumferential direction S1 side of one pressure side cam portion 90L of the pressure side cam portions 90 adjacent to each other in the circumferential direction S to the end 90SB in the first circumferential direction S1 of the pressure side slipper cam surface 90S located on the second circumferential direction S2 side of the other pressure side cam portion 90M is longer than the circumferential length L2 (see Figure 3) from the end 60AB in the second circumferential direction S2 of the center side assist cam surface 60A of one center side cam portion 60 to the end 60SB in the second circumferential direction S2 of the center side slipper cam surface 60S.

[0054] Furthermore, when viewed from the axial direction of the output shaft 15, the angle θ1 (see Figure 5) formed by the center of the pressure plate 70 (here, the center 80C of the cylindrical portion 80) and the end 90AB in the first circumferential direction S1 of the pressure side assist cam surface 90A located on the first circumferential direction S1 side of one of the pressure side cam portions 90L of the pressure side cam portions 90 adjacent to each other in the circumferential direction S, and the end 90SB in the first circumferential direction S1 of the pressure side slipper cam surface 90S located on the second circumferential direction S2 side of the other pressure side cam portion 90M, is greater than the angle θ2 (see Figure 3) formed by the center 50C of the output shaft holding portion 50 and the end 60AB in the second circumferential direction S2 of the center side assist cam surface 60A of one center side cam portion 60, and the end 60SB in the second circumferential direction S2 of the center side slipper cam surface 60S. Angle θ1 is the angle between a line passing through the center 80C and end 90AB of the cylindrical portion 80 and a line passing through the center 80C and end 90SB. Angle θ2 is the angle between a line passing through the center 50C and end 60AB of the output shaft holding portion 50 and a line passing through the center 50C and end 60SB.

[0055] In addition, the length L3 (see Figure 3) in the circumferential direction S from the end 60AB in the second circumferential direction S2 of the center side assist cam surface 60A to the boss portion 54 is longer than the length L4 (see Figure 5) in the circumferential direction S from the end 90AB in the first circumferential direction S1 of the pressure side assist cam surface 90A to the insertion hole 84H.

[0056] Also, as viewed from the axial direction of the output shaft 15, an angle θ3 (see FIG. 3) between the center 50C of the output shaft holding portion 50, the end 60AB in the second circumferential direction S2 of the center-side assist cam surface 60A of the center-side cam portion 60, and the axis 54C of the boss portion 54 is larger than an angle θ4 (see FIG. 5) between the center of the pressure plate 70 (here, the center 80C of the cylindrical portion 80), the end 90AB in the first circumferential direction S1 of the pressure-side assist cam surface 90A, and the center 84HC of the insertion hole 84H. The angle θ3 is an angle between a straight line passing through the center 50C and the end 60AB of the output shaft holding portion 50 and a straight line passing through the center 50C and the axis 54C of the boss portion 54. The angle θ4 is an angle between a straight line passing through the center 80C and the end 90AB of the cylindrical portion 80 and a straight line passing through the center 80C and the center 84HC of the insertion hole 84H.

[0057] A predetermined amount of clutch oil is filled inside the clutch device 10. The clutch oil flows through the hollow portion 15H of the output shaft 15 into the clutch center 40 and the pressure plate 70, and is then supplied to the input side rotating plate 20 and the output side rotating plate 22 through the gap between the center side fitting portion 58 and the pressure side fitting portion 88 and the oil discharge hole 49. The clutch oil absorbs heat and suppresses wear of the friction material. The clutch device 10 of this embodiment is a so-called wet-type multi-plate friction clutch device.

[0058] Next, the operation of the clutch device 10 of this embodiment will be described. As described above, the clutch device 10 is disposed between the engine and the transmission of the motorcycle, and transmits or cuts off the rotational driving force of the engine to the transmission when the rider operates the clutch operating lever.

[0059] In the clutch device 10, when the rider of the motorcycle does not operate the clutch operating lever, the clutch release mechanism (not shown) does not press the push rod 16A, and the pressure plate 70 presses the input side rotating plate 20 by the biasing force (elastic force) of the pressure spring 25. As a result, the clutch center 40 is in a clutch-on state in which the input side rotating plate 20 and the output side rotating plate 22 are pressed against each other and frictionally connected, and is driven to rotate. That is, the rotational driving force of the engine is transmitted to the clutch center 40, and the output shaft 15 is driven to rotate.

[0060] In the clutch ON state, the clutch oil that flows inside the hollow portion H of the output shaft 15 and flows out from the tip end 15T of the output shaft 15 drops or flies into the cylindrical portion 80 and adheres thereto (see arrow F in FIG. 1). The clutch oil that adheres to the inside of the cylindrical portion 80 is guided into the clutch center 40. As a result, the clutch oil flows out to the outside of the clutch center 40 through the oil discharge hole 49. The clutch oil also flows out to the outside of the clutch center 40 through the gap between the center side fitting portion 58 and the pressure side fitting portion 88. The clutch oil that flows out to the outside of the clutch center 40 is then supplied to the input side rotating plate 20 and the output side rotating plate 22.

[0061] On the other hand, when the rider of the motorcycle operates the clutch operating lever in the clutch ON state, the clutch release mechanism (not shown) presses the push rod 16A, and the pressure plate 70 is displaced in a direction (second direction D2) away from the clutch center 40 against the biasing force of the pressure spring 25. As a result, the clutch center 40 enters a clutch OFF state in which the frictional connection between the input side rotating plate 20 and the output side rotating plate 22 is released, and the rotational drive is attenuated or stopped. In other words, the rotational drive force of the engine is cut off from the clutch center 40.

[0062] In the clutch OFF state, the clutch oil that flows inside the hollow portion H of the output shaft 15 and flows out from the tip portion 15T of the output shaft 15 is led into the clutch center 40, just as in the clutch ON state. At this time, the pressure plate 70 is separated from the clutch center 40, so the amount of engagement between the center side fitting portion 58 and the pressure side fitting portion 88 decreases. As a result, the clutch oil in the cylindrical portion 80 flows out of the clutch center 40 more actively and flows to various places inside the clutch device 10. In particular, the clutch oil can be actively led between the input side rotating plate 20 and the output side rotating plate 22, which are separated from each other.

[0063] When the driver releases the clutch operating lever in the clutch OFF state, the pressure applied to the pressure plate 70 by the clutch release mechanism (not shown) via the push member 16B is released, and the pressure plate 70 is displaced in a direction approaching the clutch center 40 (first direction D1) by the force of the pressure spring 25.

[0064] As described above, according to the clutch device 10 of this embodiment, when the pressure side top surface 90C and the center side top surface 60C are located at the same position with respect to direction D, and the end 84HB on the second circumferential direction S2 side of the insertion hole 84H is in contact with the boss portion 54, the end 90AB in the first circumferential direction S1 of the pressure side assist cam surface 90A is located closer to the first circumferential direction S1 than the end 60AB in the second circumferential direction S2 of the center side assist cam surface 60A, and the end 90SB in the first circumferential direction S1 of the pressure side slipper cam surface 90S is located closer to the first circumferential direction S1 than the end 60SB in the second circumferential direction S2 of the center side slipper cam surface 60S. According to the above embodiment, even if the pressure plate 70 is brought vigorously close to the clutch center 40 when the clutch center 40 and the pressure plate 70 are assembled, the pressure-side top surface 90C and the center-side top surface 60C come into contact with each other first. That is, since the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S do not come into contact with each other first, it is possible to prevent the center-side slipper cam surface 60S from being damaged by the end 90SB of the pressure-side slipper cam surface 90S in the first circumferential direction S1. In addition, when the pressure-side top surface 90C and the center-side top surface 60C are located at the same position with respect to the direction D and the end 84HB of the insertion hole 84H on the second circumferential direction S2 side comes into contact with the boss portion 54, the formulas LB>LA and LC>LA are satisfied. According to the above embodiment, the pressure plate 70 can be assembled to the clutch center 40 by rotating the pressure plate 70 in the second circumferential direction S2. Furthermore, when the pressure-side top surface 90C and the center-side top surface 60C are located at the same position in the direction D and the end 84HB of the insertion hole 84H on the second circumferential direction S2 side is in contact with the boss portion 54, the formula LD≧LE / 4 is satisfied, and the formula LF≧LG / 4 is satisfied. When the pressure-side top surface 90C and the center-side top surface 60C come into contact with each other, if there is little overlap between the pressure-side top surface 90C and the center-side top surface 60C in the circumferential direction S, there is a risk that the pressure-side assist cam surface 90A and the center-side assist cam surface 60A will be damaged.However, since the equation LD≧LE / 4 is satisfied and the equation LF≧LG / 4 is satisfied, a sufficient overlapping area between the pressure side top surface 90C and the center side top surface 60C is secured, thereby suppressing damage to the pressure side assist cam surface 90A and the center side assist cam surface 60A.

[0065] In the clutch device 10 of this embodiment, LD, LE, LF, and LG satisfy the formulas LD ≥ LE / 2 and LF ≥ LG / 2. According to the above aspect, the overlapping portion between the pressure side top surface 90C and the center side top surface 60C is sufficiently secured, and damage to the pressure side assist cam surface 90A and the center side assist cam surface 60A can be suppressed.

[0066] In the clutch device 10 of this embodiment, when the input side rotating plate 20 and the output side rotating plate 22 are assembled and the stopper plate 100 is attached to the boss portion 54, the pressure side top surface 90C is located closer to the first direction D1 than the center side top surface 60C. In this manner, the clutch center 40 and pressure plate 70 of this embodiment can be reliably assembled.

[0067] <Second embodiment> FIG. 13 is a cross-sectional view of a pressure plate 70 and a clutch center 40 according to the second embodiment, which is partially enlarged. FIG. 13 corresponds to a cross-sectional view cut by a plane passing through the axis 54C of the boss portion 54 and extending in the circumferential direction S and the axial direction of the output shaft 15. As shown in FIG. 13, the pressure plate 70 includes a ring-shaped spring seat 85 housed in a spring housing portion 84. The ring-shaped spring seat 85 includes, for example, an O-shape (O-ring) and a C-shape (C-ring). The spring seat 85 is formed in an elliptical shape. The spring seat 85 is arranged so as to be movable in the circumferential direction S within the spring housing portion 84. In the example shown in FIG. 13, the spring seat 85 is located closest to the second circumferential direction S2 in the spring housing portion 84. That is, an end portion 85A of the spring seat 85 in the second circumferential direction S2 contacts an inner wall 84A of the spring housing portion 84. The boss portion 54 penetrates the spring seat 85. The pressure spring 25 is disposed on a surface 85M of the spring seat 85 on the second direction D2 side.

[0068] As shown in FIG. 13, when the center-side top surface 60C and the pressure-side top surface 90C are located at the same position in the moving direction D, the total length of the first length LS1 and the second length LS2 is longer than the third length LS3. That is, (LS1+LS2)>LS3 is established. Here, the first length LS1 is the distance in the circumferential direction S between the end 60AB of the center-side assist cam surface 60A in the second circumferential direction S2 and the end 90AB of the pressure-side assist cam surface 90A in the first circumferential direction S1. The second length LS2 is the distance in the circumferential direction S between the end 60SB of the center-side slipper cam surface 60S in the second circumferential direction S2 and the end 90SB of the pressure-side slipper cam surface 90S in the first circumferential direction S1. The third length LS3 is the distance in the circumferential direction S between the first inner edge 85HA and the end 84HA when the spring seat 85 is located closest to the second circumferential direction S2 in the spring accommodating portion 84, a first inner edge 85HA which is the inner edge of the spring seat 85 on the first circumferential direction S1 side is in contact with the boss portion 54, and an end 84HA which is the inner edge of the insertion hole 84H on the first circumferential direction S1 side is not in contact with the boss portion 54. The end 84HA is an example of the first inner edge.

[0069] <Third embodiment> FIG. 14 is an exploded perspective view of a clutch center 240 and a pressure plate 270 of a clutch device 210 according to the third embodiment.

[0070] The clutch center 240 is accommodated in the clutch housing 30 (see FIG. 1). The clutch center 240 is disposed concentrically with the clutch housing 30. As shown in FIG. 14, the clutch center 240 has a main body 242 and a flange 268 that is connected to the outer circumferential edge of the main body 242 on the first direction D1 side and extends radially outward. The main body 242 protrudes in the second direction D2 beyond the flange 268. The clutch center 240 does not hold the output side rotating plate 22. The clutch center 240 is driven to rotate together with the output shaft 15 (see FIG. 1).

[0071] 14, the main body 242 includes an output shaft holding portion 250, a plurality of center side cam portions 60, and a center side fitting portion 258. The center side cam portion 60 is formed so as to protrude in the second direction D2 beyond the flange 268. The center side cam portion 60 is located radially outward of the output shaft holding portion 250.

[0072] The output shaft holding portion 250 is formed in a cylindrical shape. An insertion hole 251 into which the output shaft 15 (see FIG. 1) is inserted and spline-fitted is formed in the output shaft holding portion 250. The insertion hole 251 is formed penetrating the main body 242. An inner circumferential surface 250A of the output shaft holding portion 250 that forms the insertion hole 251 has a plurality of spline grooves formed along the axial direction. The output shaft 15 is connected to the output shaft holding portion 250.

[0073] 14, the clutch center 240 has a plurality of (three in this embodiment) boss portions 54. The boss portions 54 are located radially outward from the output shaft holding portion 250. The boss portions 54 are provided on the main body 242.

[0074] 14, the clutch center 240 has a center-side cam hole 243H that penetrates the main body 242 and a portion of the flange 268. The center-side cam hole 243H penetrates the main body 242 and the flange 268 in direction D. The center-side cam hole 243H extends from the side of the output shaft holding portion 250 to the flange 268. The center-side cam hole 243H is formed between the center-side assist cam surface 60A of the center-side cam portion 60 and the boss portion 54. When viewed from the axial direction of the clutch center 240, the center-side assist cam surface 60A and a portion of the center-side cam hole 243H overlap with each other.

[0075] As shown in Fig. 14, the center side fitting portion 258 is provided on the main body 242. The center side fitting portion 258 is located radially outward from the center side cam portion 60. The center side fitting portion 258 is located on the first direction D1 side from the center side cam portion 60. The center side fitting portion 258 is configured to be slidably fitted into the pressure side fitting portion 288 (see Fig. 15).

[0076] The pressure plate 270 is provided so as to be capable of approaching or separating from the clutch center 240 and rotatable relative thereto. The pressure plate 270 is configured so as to be capable of pressing the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 270 is arranged concentrically with the clutch center 240 and the clutch housing 30. The pressure plate 270 has a cylindrical main body 272 and a flange 298 extending radially outward from the outer circumferential edge of the main body 272. The pressure plate 270 holds the input side rotating plate 20 and a plurality of output side rotating plates 22 arranged alternately in the direction D. In this embodiment, the pressure plate 270 holds all of the output side rotating plates 22.

[0077] As shown in FIG. 15, the main body 272 includes an annular base wall 273, an outer peripheral wall 275 located radially outside the base wall 273 and extending in the first direction D1, a cylindrical portion 280 provided in the center of the base wall 273, a plurality of pressure-side cam portions 90 connected to the base wall 273 and the outer peripheral wall 275, a pressure-side fitting portion 288, and a spring accommodating portion 84 (see FIG. 14). The pressure-side cam portion 90 is formed so as to protrude from the main body 272 in the first direction D1. The pressure-side cam portion 90 is located radially outside the cylindrical portion 280. The pressure-side cam portion 90 is located radially inside the outer peripheral wall 275.

[0078] The cylindrical portion 280 is formed in a cylindrical shape. The cylindrical portion 280 is formed integrally with the pressure side cam portion 90. The cylindrical portion 280 accommodates the tip portion 15T (see FIG. 1) of the output shaft 15. The cylindrical portion 280 accommodates the release bearing 18 (see FIG. 1). The cylindrical portion 280 is a portion that receives a pressing force from the push member 16B. The cylindrical portion 280 is a portion that receives the clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0079] As shown in FIG. 15, the outer peripheral wall 275 of the pressure plate 270 is disposed radially outward from the cylindrical portion 280. The outer peripheral wall 275 is formed in an annular shape extending in the direction D. A spline fitting portion 276 is provided on an outer peripheral surface 275A of the outer peripheral wall 275. The spline fitting portion 276 has a plurality of pressure side fitting teeth 277 extending in the axial direction of the pressure plate 270 along the outer peripheral surface 275A of the outer peripheral wall 275, a plurality of spline grooves 278 formed between adjacent pressure side fitting teeth 277 and extending in the axial direction of the pressure plate 270, and an oil discharge hole 279. The pressure side fitting teeth 277 hold the output side rotating plate 22. The pressure side fitting teeth 277 are arranged in the circumferential direction S. The pressure side fitting teeth 277 are formed at equal intervals in the circumferential direction S. The pressure side fitting teeth 277 are formed in the same shape. The pressure side fitting teeth 277 protrude radially outward from the outer peripheral surface 275A of the outer peripheral wall 275. The oil discharge hole 279 is formed penetrating the outer peripheral wall 275 in the radial direction. The oil discharge hole 279 is formed between the adjacent pressure side fitting teeth 277. That is, the oil discharge hole 279 is formed in the spline groove 278. The oil discharge hole 279 is formed on the side of the pressure side cam portion 90. The oil discharge hole 279 is formed on the side of the pressure side assist cam surface 90A of the pressure side cam portion 90. The oil discharge hole 279 is formed on the first circumferential direction S1 side of the pressure side assist cam surface 90A. The oil discharge hole 279 is formed on the second circumferential direction S2 side of the pressure side slipper cam surface 90S. In this embodiment, the oil discharge holes 279 are formed in threes at three locations in the circumferential direction S of the outer peripheral wall 275. The oil discharge holes 279 are arranged at positions equally spaced apart in the circumferential direction S. The oil discharge holes 279 communicate between the inside and the outside of the pressure plate 270. The oil discharge holes 279 are holes that discharge the clutch oil that has flowed out from the output shaft 15 into the pressure plate 270 to the outside of the pressure plate 270. Here, the oil discharge holes 279 discharge the clutch oil that flows on the inner circumferential surface 275B side of the outer peripheral wall 275 to the outside of the pressure plate 270.At least a portion of the oil drain hole 279 is provided in a position facing the center side fitting portion 258 (see FIG. 14).

[0080] The output side rotating plate 22 is held by a spline fitting portion 276 of the pressure plate 270. The output side rotating plate 22 is held by spline fitting to pressure side fitting teeth 277 and spline grooves 278. The output side rotating plate 22 is provided so as to be displaceable along the axial direction of the pressure plate 270. The output side rotating plate 22 is provided so as to be rotatable integrally with the pressure plate 270.

[0081] As shown in FIG. 14 and FIG. 15, the pressure plate 270 has a pressure-side cam hole 273H penetrating a part of the base wall 273. The pressure-side cam hole 273H penetrates the base wall 273 in the direction D. The pressure-side cam hole 273H is located radially outward from the cylindrical portion 80. The pressure-side cam hole 273H extends from the side of the cylindrical portion 80 to the outer peripheral wall 275. The pressure-side cam hole 273H is formed penetrating between the adjacent pressure-side cam portions 90. The pressure-side cam hole 273H is formed penetrating between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of the adjacent pressure-side cam portions 90. When viewed from the axial direction of the pressure plate 270, the pressure-side assist cam surface 90A and a part of the pressure-side cam hole 273H overlap. Clutch oil flows from the outside of the pressure plate 270 into the pressure side cam hole 273H.

[0082] As shown in FIG. 15, the pressure side fitting portion 288 is located radially outward from the cylindrical portion 280. The pressure side fitting portion 288 is located radially outward from the pressure side cam portion 90. The pressure side fitting portion 288 is located closer to the first direction D1 than the pressure side cam portion 90. The pressure side fitting portion 288 is formed on the inner peripheral surface 275B of the outer peripheral wall 275. The pressure side fitting portion 288 is configured to be slidably fitted onto the center side fitting portion 258 (see FIG. 14). A gap is formed between the pressure side fitting portion 288 and the center side fitting portion 258.

[0083] In the clutch center 240 and pressure plate 270 according to the third embodiment, similarly to the clutch center 40 and pressure plate 70 according to the first embodiment, in the entire range in the circumferential direction S from the position immediately before the pressure side slipper cam surface 90S and the center side slipper cam surface 60S come into contact to the position immediately before the pressure side assist cam surface 90A and the center side assist cam surface 60A come into contact, the distance L5 in the circumferential direction S between the boss portion 54 and the end 84HA on the pressure side assist cam surface 90A side (i.e., the first circumferential direction S1 side) of the insertion hole 84H is longer than the distance L6 in the circumferential direction S between the boss portion 54 and the end 84HB on the pressure side slipper cam surface 90S side (i.e., the second circumferential direction S2 side) of the insertion hole 84H (see FIG. 10).

[0084] In the clutch device 210 of this embodiment, the output side rotating plate 22 is held only by the pressure side fitting teeth 277. According to the above-described embodiment, the structure of the clutch center 240 can be further simplified.

[0085] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0086] In the above-described third embodiment, the clutch center 240 is configured not to hold the output side rotating plate 22, but is not limited to this. The clutch center 240 may have center side fitting teeth having a configuration similar to the pressure side fitting teeth 77 of the first embodiment that can hold the output side rotating plate 22.

[0087] In the above-described embodiment, the pressure-side assist cam surface 90A, the pressure-side slipper cam surface 90S, the center-side assist cam surface 60A, and the center-side slipper cam surface 60S are parallel to each other, but are not limited to this. For example, if the pressure-side assist cam surface 90A and the center-side assist cam surface 60A are parallel to each other and the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S are parallel to each other, the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S (the center-side assist cam surface 60A and the center-side slipper cam surface 60S) do not have to be parallel to each other. [Explanation of symbols]

[0088] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 25 Pressure Spring 30 Clutch housing 40 Clutch center 50 Output shaft holder 54 Boss 60 Center side cam part 60A Center side assist cam surface 60AB second circumferential end 60C Center side top surface 60S Center side slipper cam surface 60SB Second circumferential end 70 Pressure Plate 84 Spring housing 84H Insertion hole 90 Pressure side cam part 90A Pressure side assist cam surface 90AB first circumferential end 90C Pressure side top surface 90S Pressure side slipper cam surface 90SB First circumferential end D1 First direction D2 Second direction S1 First circumferential direction S2 Second circumferential direction

Claims

1. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotary plates that are rotationally driven by the rotational drive of the input shaft and that is rotationally driven together with the output shaft; a pressure plate that is provided so as to be capable of approaching or separating from the clutch center and rotatable relative to the clutch center, that holds at least a part of a plurality of output side rotating plates that are arranged alternately with the input side rotating plate, and that is capable of pressing the input side rotating plate and the output side rotating plate, The clutch center is an output shaft holding portion to which the output shaft is connected; a plurality of center side cam portions each having a center side assist cam surface located radially outward of the output shaft holding portion and generating a force in a direction that moves the pressure plate closer to the clutch center in order to increase the pressing force between the input side rotating plate and the output side rotating plate when the center side cam portions rotate relative to the pressure plate, a center side slipper cam surface that moves the pressure plate away from the clutch center in order to decrease the pressing force between the input side rotating plate and the output side rotating plate, and a center side top surface located between the center side assist cam surface and the center side slipper cam surface; a boss portion located radially outward from the output shaft holding portion and extending toward the pressure plate, The pressure plate is a plurality of pressure-side cam portions each having a pressure-side assist cam surface configured to be capable of contacting the center-side assist cam surface when rotating relative to the clutch center, and generating a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input side rotating plate and the output side rotating plate, a pressure-side slipper cam surface configured to be capable of contacting the center-side slipper cam surface, and moving the pressure plate away from the clutch center in order to reduce the pressing force between the input side rotating plate and the output side rotating plate, and a pressure-side top surface located between the pressure-side assist cam surface and the pressure-side slipper cam surface; a spring accommodating portion that is formed in the pressure-side cam portion so as to be recessed from the second direction to the first direction, where a direction in which the pressure plate approaches and moves away from the clutch center is defined as a movement direction, a direction in which the pressure plate approaches the clutch center is defined as a first direction, and a direction in which the pressure plate moves away from the clutch center is defined as a second direction, and that accommodates a pressure spring that urges the pressure plate in the first direction, The spring accommodating portion has an insertion hole through which the boss portion is inserted, a circumferential distance between the boss portion and the end portion of the insertion hole on the pressure-side slipper cam surface side is shorter than a circumferential distance between the boss portion and the end portion of the insertion hole on the pressure-side assist cam surface side, in an entire circumferential range from a position immediately before contact between the pressure-side slipper cam surface and the center-side slipper cam surface to a position immediately before contact between the pressure-side assist cam surface and the center-side assist cam surface, a first circumferential direction is a direction from one of the pressure side cam portions to the other of the pressure side cam portions, and a second circumferential direction is a direction from the other of the pressure side cam portions to one of the pressure side cam portions, the pressure plate and the clutch center are configured to rotate in the first circumferential direction, In a state in which the pressure-side top surface and the center-side top surface are located at the same position with respect to the moving direction and the end portion of the insertion hole on the second circumferential direction side and the boss portion are in contact with each other, The first circumferential end of the pressure-side assist cam surface is located on the first circumferential side of the second circumferential end of the center-side assist cam surface, and the first circumferential end of the pressure-side slipper cam surface is located on the first circumferential side of the second circumferential end of the center-side slipper cam surface, and When the circumferential length from the first circumferential end of the pressure-side assist cam surface to the second circumferential end of the center-side assist cam surface is defined as LA, the circumferential length from the first circumferential end of the insertion hole to the boss portion is defined as LB, and the circumferential length from the first circumferential end of the pressure-side slipper cam surface to the second circumferential end of the center-side slipper cam surface is defined as LC, the formulas LB>LA and LC>LA are satisfied, and When a length in the movement direction from a point where a straight line that is parallel to the movement direction and that passes through the second circumferential end of the center-side assist cam surface intersects with the pressure-side assist cam surface to the pressure-side top surface is defined as LD, and a length in the movement direction of the pressure-side assist cam surface is defined as LE, the formula LD≧LE / 4 is satisfied, and A clutch device which satisfies the formula LF≧LG / 4, where LF is the length in the movement direction from the point where a straight line parallel to the movement direction and passing through the first circumferential end of the pressure side assist cam surface intersects with the center side assist cam surface to the center side top surface, and LG is the length in the movement direction of the center side assist cam surface.

2. 2. The clutch device according to claim 1, wherein the LD, the LE, the LF, and the LG satisfy the expressions LD≧LE / 2 and LF≧LG / 2.

3. a stopper plate that is provided so as to be able to come into contact with the pressure plate and that prevents the pressure plate from moving away from the clutch center in the second direction by a predetermined distance or more; The boss portion is formed with a screw hole for attaching the stopper plate, 3. The clutch device according to claim 1, wherein when the input side rotating plate and the output side rotating plate are assembled and the stopper plate is attached to the boss portion, the pressure side top surface is located on the first direction side of the center side top surface.

4. the pressure plate includes pressure-side fitting teeth that hold the output-side rotating plate, 3. The clutch device according to claim 1, wherein the output side rotating plate is held only by the pressure side fitting teeth.

Images