Clutch device and motorcycle

Abstract

To supply clutch oil to an input side rotating plate and an output side rotating plate by efficiently feeding the clutch oil in a flange of a pressure plate.SOLUTION: A clutch device 10 includes a pressure plate 70 which is provided so as to be approachable to and separable from a clutch center 40 and relatively rotatable, and can press an input side rotating plate 20 and an output side rotating plate 22. The pressure plate 70 includes a flange 98 extending to a radial outer side from an outer peripheral edge of a body 72, and a plurality of pressure side engagement teeth 77 formed on the flange 98. The flange 98 includes a pressing surface 98A imparting pressing force to the input side rotating plate 20 and the output side rotating plate 22, and an engagement tooth forming surface 98B positioned on a radial inner side than the pressing surface 98A and positioned between the adjacent pressure side engagement teeth 77. The pressing surface 98A and the engagement tooth forming surface 98B are almost flush with each other.SELECTED DRAWING: Figure 9A

Description

[Technical field]

[0001] The present invention relates to a clutch device and a motorcycle, and more particularly to a clutch device that selectively transmits or cuts off the rotational driving force of an input shaft that is rotationally driven by a prime mover such as an engine to an output shaft, and a motorcycle equipped with the same. [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 discloses a clutch device that includes a clutch center (clutch member) that holds an output side rotating plate (driven side clutch plate) and a pressure plate (pressure member) that is provided 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 the input side rotating plate and the output side rotating plate. In this way, the clutch center and the pressure plate are assembled together and used in the clutch device.

[0004] In the clutch device of Patent Document 1, the clutch center has center-side fitting teeth (an outer peripheral wall on which a spline is formed) and the pressure plate has pressure-side fitting teeth as portions for holding the output-side rotating plate. When the clutch center and the pressure plate are assembled, the center-side fitting teeth and the pressure-side fitting teeth are configured to overlap in the radial direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6894792 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, clutch oil flowing out from the output shaft flows inside the clutch center. Some of the clutch oil passes between the clutch center and the pressure plate and flows to the flange of the pressure plate. Here, the flange is formed with pressure side fitting teeth that hold the input side rotating plate and the output side rotating plate. For this reason, it is desirable to efficiently flow the clutch oil in the flange and supply the clutch oil to the input side rotating plate and the output side rotating plate.

[0007] The present invention has been made in consideration of these points, and its object is to provide a clutch device that can efficiently flow clutch oil at the flange of the pressure plate and supply clutch oil to the input side rotating plate and the output side rotating plate, and a motorcycle equipped with the same. [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, holds a plurality of output side rotating plates arranged alternately with the input side rotating plates, and is rotationally driven 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 be rotatable relative to the clutch center and can press the input side rotating plate and the output side rotating plate. The pressure plate includes a main body, a flange that extends radially outward from an outer circumferential edge of the main body, and a plurality of pressure side fitting teeth that are formed on the flange, hold the input side rotating plate and the output side rotating plate, and are arranged in the circumferential direction. The flange includes a pressing surface that applies a pressing force to the input side rotating plate and the output side rotating plate, and a fitting tooth forming surface that is located radially inward of the pressing surface and is located between adjacent pressure side fitting teeth. The pressing surface and the mating teeth forming surface are formed to be substantially flush with each other.

[0009] In the clutch device according to the present invention, the pressing surface and the mating teeth forming surface are formed to be substantially flush with each other. Therefore, the clutch oil that passes between the clutch center and the pressure plate and flows to the flange of the pressure plate reaches the mating teeth forming surface and then flows smoothly to the pressing surface. In other words, because the clutch oil flows efficiently in the flange, the clutch oil can be efficiently supplied to the input side rotating plate and the output side rotating plate that are held by the pressure side mating teeth.

[0010] Another 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, the clutch device including: a clutch center 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, that holds a plurality of output side rotating plates arranged alternately with the input side rotating plates, and that rotates together with the output shaft; and a pressure plate that is provided so as to be able to approach or move away from the clutch center and to rotate relatively thereto, and that can press the input side rotating plates and the output side rotating plates. The pressure plate includes a main body, a flange extending radially outward from an outer circumferential edge of the main body, and a plurality of pressure side fitting teeth formed on the flange, that hold the input side rotating plates and the output side rotating plates, and that are arranged in the circumferential direction. The flange includes a fitting tooth forming surface located between adjacent pressure side fitting teeth, and a connection surface located radially between the main body and the pressure side fitting teeth. The mating teeth forming surface and the connecting surface are formed to be substantially flush with each other.

[0011] In the clutch device according to the present invention, the mating teeth forming surface and the connection surface are formed to be substantially flush with each other. Therefore, the clutch oil that passes between the clutch center and the pressure plate and flows to the flange of the pressure plate reaches the connection surface and then flows smoothly to the mating teeth forming surface. In other words, because the clutch oil flows efficiently in the flange, the clutch oil can be efficiently supplied to the input side rotating plate and the output side rotating plate that are held by the pressure side mating teeth. Effect of the Invention

[0012] According to the present invention, it is possible to provide a clutch device that allows clutch oil to flow efficiently at the flange of the pressure plate and can supply clutch oil to the input side rotating plate and the output side rotating plate. [Brief description of the drawings]

[0013] [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 a plan view showing a state in which the clutch center and the pressure plate according to one embodiment are combined. [Figure 9A] FIG. 9A is an enlarged cross-sectional view of a portion of the pressure plate. [Figure 9B] FIG. 9B is an enlarged cross-sectional view of a portion of the pressure plate before lathe processing. [Figure 10A] FIG. 10A is a schematic diagram for explaining the action of the center side assist cam surface and the pressure side assist cam surface. [Figure 10B] FIG. 10B is a schematic diagram for explaining the action of the center-side slipper cam surface and the pressure-side slipper cam surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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.

[0015] 1 is a cross-sectional view of a clutch device 10 according to this 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.

[0016] In the following description, the direction in which the pressure plate 70 and the clutch center 40 of the clutch device 10 are aligned is defined as direction D, the direction in which the pressure plate 70 approaches the clutch center 40 is defined as a first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is defined as a second direction D2. The circumferential direction of the clutch center 40 and the pressure plate 70 is defined as 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 defined 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 defined 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 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] As shown in Fig. 1, the clutch center 40 is accommodated in the clutch housing 30. The clutch center 40 is disposed concentrically with the clutch housing 30. 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 an input side rotating plate 20 and a plurality of output side rotating plates 22 arranged alternately in direction D. The clutch center 40 is driven to rotate together with the output shaft 15.

[0024] As shown in FIG. 2, the main body 42 includes an annular base wall 43, an outer peripheral wall 45 located radially outward of 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.

[0025] 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.

[0026] As shown in FIG. 2, the outer peripheral wall 45 of the clutch center 40 is disposed radially outward of the output shaft holding portion 50. A spline fitting portion 46 is provided on an outer peripheral surface 45A 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 45A 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 input side rotating plate 20 and 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 45A of the outer peripheral wall 45. The number of the center side fitting teeth 47 may be a multiple of the number of the center side cam portions 60. In this embodiment, as described later, the number of the center side cam portions 60 is three, and the number of the center side fitting teeth 47 is 30. The number of the center side fitting teeth 47 does not have to be a multiple of the number of the center side cam portions 60. 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 first circumferential direction S1 side of the center-side slipper cam surface 60S. The oil discharge hole 49 is formed on the second circumferential direction S2 side of the boss portion 54 described later. In this embodiment, the oil discharge holes 49 are formed in threes at three locations 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 outside of the clutch center 40. The oil discharge hole 49 is a hole that discharges 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. Here, the oil discharge hole 49 discharges the clutch oil that flows on the inner circumferential surface 45B side of the outer peripheral wall 45 to the outside of the clutch center 40.At least a portion of the oil drain hole 49 is provided in a position facing a pressure side fitting portion 88, which will be described later.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] As shown in FIG. 3, the center-side cam portion 60 is located radially outside the output shaft holding portion 50. The center-side cam portion 60 has a center-side assist cam surface 60A and a center-side slipper cam surface 60S. 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 the center-side assist cam surface 60A rotates 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 portions 60 adjacent to each other in the circumferential direction S, the center-side assist cam surface 60A of one center-side cam portion 60L and the center-side slipper cam surface 60S of the other center-side cam portion 60M are disposed opposite each other in the circumferential direction S.

[0031] 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.

[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 penetrates the base wall 43 in direction D. 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. 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 45B of the outer peripheral wall 45. The center-side fitting portion 58 is configured to be slidably fitted to 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 (see FIG. 1) 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.

[0034] 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 of rotating relatively 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 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 a plurality of output side rotating plates 22 that are arranged alternately with the input side rotating plate 20.

[0035] 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).

[0036] As shown in FIG. 4, the flange 98 extends radially outward from the outer periphery of the main body 72. Here, the flange 98 extends radially outward from the outer periphery of the pressure side fitting portion 88. The flange 98 includes a pressing surface 98A that applies a pressing force to the input side rotating plate 20 and the output side rotating plate 22, a fitting tooth forming surface 98B located radially inward from the pressing surface 98A, and a connecting surface 98C located radially inward from the fitting tooth forming surface 98B. The pressing surface 98A is a surface that directly or indirectly contacts the input side rotating plate 20 and the output side rotating plate 22. The pressing surface 98A sandwiches the input side rotating plate 20 and the output side rotating plate 22 between itself and the flange 68 of the clutch center 40. The fitting tooth forming surface 98B has pressure side fitting teeth 77 formed thereon, which will be described later. The fitting tooth forming surface 98B is located between the adjacent pressure side fitting teeth 77. The connection surface 98C is connected to the main body 72. Here, the connection surface 98C is connected to the pressure-side fitting portion 88. The connection surface 98C is located between the main body 72 and the pressure-side fitting teeth 77 in the radial direction.

[0037] As shown in FIG. 4, the pressing surface 98A and the mating tooth forming surface 98B are formed to be substantially flush. The mating tooth forming surface 98B and the connecting surface 98C are formed to be substantially flush. The pressing surface 98A, the mating tooth forming surface 98B, and the connecting surface 98C are formed to be substantially flush. Here, "substantially flush" includes a state in which the surfaces are completely flush with no step, and a state in which the surfaces are substantially flush with each other but have a step of about 0 mm to 0.3 mm. In this embodiment, as shown in FIG. 9A, the mating tooth forming surface 98B and the connecting surface 98C are completely flush, and the pressing surface 98A and the mating tooth forming surface 98B are substantially flush with a slight step. Here, the slight step between the pressing surface 98A and the mating tooth forming surface 98B is due to lathe processing of the surface of the pressing surface 98A. 9B, the pressing surface 98A, the mating teeth forming surface 98B, and the connecting surface 98C are completely flush with each other before lathe processing. If the pressing surface 98A, the mating teeth forming surface 98B, and the connecting surface 98C are completely flush with each other before lathe processing, the pressing surface 98A, the mating teeth forming surface 98B, and the connecting surface 98C will usually be approximately flush with each other after lathe processing.

[0038] As shown in FIG. 4 and FIG. 5, the flange 98 has a through hole 99. The through hole 99 penetrates the flange 98 in the direction D. In this embodiment, the through hole 99 is formed at three positions in the circumferential direction S of the flange 98. The three through holes 99 are arranged at equal intervals in the circumferential direction S. The number of the through holes 99 is not limited to three. The multiple through holes 99 do not have to be arranged at equal intervals. The through hole 99 is formed radially inward from the pressing surface 98A. The through hole 99 is formed in the fitting tooth forming surface 98B. In this embodiment, the through hole 99 is formed from the fitting tooth forming surface 98B to the connecting surface 98C. The through hole 99 is located between the adjacent pressure side fitting teeth 77 with respect to the circumferential direction S. As shown in FIG. 1, the through hole 99 is formed so that the opening area increases from the front surface 98F of the flange 98 toward the back surface 98R. The through hole 99 is formed so that the inner diameter increases from the front surface 98F of the flange 98 toward the back surface 98R. The through hole 99 is formed so that the cross-sectional area increases from the front surface 98F of the flange 98 toward the back surface 98R. A dedicated jig is inserted into the through hole 99 when assembling the clutch device 10. This jig is inserted in the first direction D1 from the outside of the pressure plate 70. By using the jig, the positions of the input side rotating plate 20 and the output side rotating plate 22 are adjusted. When the assembly of the clutch device 10 is completed, the jig is removed and the through hole 99 is opened. Therefore, when the clutch device 10 is used, that is, when the pressure plate 70 rotates, the clutch oil that flows along the outer surface of the pressure plate 70 toward the edge due to centrifugal force easily flows in from the through hole 99. This makes it possible to efficiently supply clutch oil to the input side rotating plate 20 and the output side rotating plate 22 held by the pressure side fitting teeth 77.

[0039] 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.

[0040] 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.

[0041] As shown in FIG. 5, the pressure-side cam portion 90 is located radially outside the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also FIG. 7) and a pressure-side slipper cam surface 90S. 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 (pressure contact 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.

[0042] 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. 10A. 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.

[0043] 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. 10B. 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.

[0044] As shown in FIG. 4 and FIG. 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 radially outward position from the pressure side fitting portion 88. The pressure side cam hole 73H is formed penetrating between the adjacent pressure side cam portions 90. The pressure side cam hole 73H 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. As shown in FIG. 5 and FIG. 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.

[0045] As shown in Figs. 6 and 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). An insertion hole 84H into which the boss portion 54 (see Fig. 2) is inserted is formed through the spring accommodating portion 84. 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.

[0046] 1, the pressure spring 25 is accommodated in the spring accommodating portion 84. The pressure spring 25 is held by 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.

[0047] As shown in Fig. 4, the pressure side fitting portion 88 is provided on the main body 72. 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).

[0048] As shown in FIG. 4, the pressure plate 70 has a plurality of pressure side fitting teeth 77 formed on a flange 98. The pressure side fitting teeth 77 hold the input side rotating plate 20 and the output side rotating plate 22. The pressure side fitting teeth 77 are located radially outward from the cylindrical portion 80. 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 formed on a fitting tooth forming surface 98B of the flange 98. The pressure side fitting teeth 77 protrude from the fitting tooth forming surface 98B in the first direction D1. The pressure side fitting teeth 77 are arranged 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.

[0049] 9 is a plan view showing a state in which the clutch center 40 and the pressure plate 70 are assembled. In the state shown in FIG. 9, 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. In the state shown in FIG. 9 (assembly state), the distance L1 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 shorter than the distance L2 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 in the normal state.

[0050] 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 stopper plate 100 is formed in a substantially triangular shape in a plan view.

[0051] 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.

[0052] A predetermined amount of clutch oil is filled in 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 also flows from the outside of the clutch center 40 through the hollow portion 15H of the output shaft 15 to the inside of the clutch center 40 through the pressure side cam hole 73H. 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.

[0053] 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.

[0054] 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.

[0055] In the clutch ON state, the clutch oil that flows inside the hollow portion 15H 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.

[0056] 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.

[0057] In the clutch OFF state, the clutch oil that flows inside the hollow portion 15H of the output shaft 15 and flows out from the tip end 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.

[0058] 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.

[0059] As described above, in the clutch device 10 of this embodiment, the pressing surface 98A and the mating tooth forming surface 98B are formed to be substantially flush with each other. Therefore, the clutch oil that passes between the clutch center 40 and the pressure plate 70 and flows to the flange 98 of the pressure plate 70 reaches the mating tooth forming surface 98B and then flows smoothly to the pressing surface 98A. In other words, since the clutch oil flows efficiently in the flange 98, the clutch oil can be efficiently supplied to the input side rotating plate 20 and the output side rotating plate 22 held by the pressure side mating teeth 77.

[0060] In the clutch device 10 of this embodiment, the mating teeth forming surface 98B and the connection surface 98C are formed to be substantially flush with each other. Therefore, the clutch oil that passes between the clutch center 40 and the pressure plate 70 and flows to the flange 98 of the pressure plate 70 reaches the connection surface 98C and then flows smoothly to the mating teeth forming surface 98B. In other words, since the clutch oil flows efficiently in the flange 98, the clutch oil can be efficiently supplied to the input side rotating plate 20 and the output side rotating plate 22 held by the pressure side mating teeth 77.

[0061] In the clutch device 10 of this embodiment, the flange 98 has a connection surface 98C located between the main body 72 and the pressure side fitting teeth 77 in the radial direction, and the pressing surface 98A, the fitting teeth forming surface 98B, and the connecting surface 98C are formed to be approximately flush with each other. According to the above-mentioned embodiment, the pressing surface 98A, the fitting teeth forming surface 98B, and the connecting surface 98C are formed to be approximately flush with each other. Therefore, the clutch oil that flows between the clutch center 40 and the pressure plate 70 and flows to the flange 98 of the pressure plate 70 smoothly flows to the pressing surface 98A via the fitting teeth forming surface 98B after reaching the connecting surface 98C. That is, since the clutch oil flows efficiently in the flange 98, the clutch oil can be efficiently supplied to the input side rotating plate 20 and the output side rotating plate 22 held by the pressure side fitting teeth 77.

[0062] In the clutch device 10 of this embodiment, the clutch center 40 includes an output shaft holding portion 50 to which the output shaft 15 is connected, an outer peripheral wall 45 located radially outward from the output shaft holding portion 50, a plurality of center side fitting teeth 47 arranged circumferentially and formed to hold the input side rotating plate 20 and the output side rotating plate 22 and protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45, a plurality of spline grooves 48 formed between adjacent center side fitting teeth 47, an oil discharge hole 49 formed in the spline groove 48 so as to penetrate the outer peripheral wall 45 and discharges clutch oil flowing on the inner peripheral surface 45B side of the outer peripheral wall 45 to the outside of the clutch center 40, and a center side fitting portion 58 formed on the inner peripheral surface 45B of the outer peripheral wall 45. The pressure plate 70 is provided on the main body 72 and includes a pressure-side fitting portion 88 that is slidably fitted into the center-side fitting portion 58, and the oil drain hole 49 is provided at a position facing the pressure-side fitting portion 88. According to the above embodiment, since the oil drain hole 49 is provided at a position facing the pressure-side fitting portion 88, a part of the clutch oil flowing between the pressure-side fitting portion 88 and the center-side fitting portion 58 is discharged from the oil drain hole 49 to the outside of the clutch center 40. Since the center-side fitting teeth 47 that hold the input-side rotating plate 20 and the output-side rotating plate 22 are located radially outside the oil drain hole 49, the clutch oil is effectively supplied to the input-side rotating plate 20 and the output-side rotating plate 22.

[0063] 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.

[0064] In the above-described embodiment, the center-side cam portion 60 has the center-side assist cam surface 60A and the center-side slipper cam surface 60S, but it is sufficient if it has at least one of them.

[0065] In the above-described embodiment, the pressure-side cam portion 90 has the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S, but it is sufficient if it has at least one of them. [Explanation of symbols]

[0066] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 30 Clutch housing 40 Clutch center 42 Main unit 45 Outer wall 45A Outer surface 45B Inner surface 47 Center side mating teeth 48 Spline groove 49 Oil drain hole 50 Output shaft holder 58 Center side fitting part 60 Center side cam part 60A Center side assist cam surface 60S Center side slipper cam surface 68 Flange 70 Pressure Plate 72 Main Body 77 Pressure side mating teeth 80 Cylindrical part 88 Pressure side fitting part 90 Pressure side cam part 90A Pressure side assist cam surface 90S Pressure side slipper cam surface 98 Flange 98A Pressing surface 98B Interlocking tooth forming surface 98C Connection Surface

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 rotating plates that are rotationally driven by the rotational drive of the input shaft, holds a plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and 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 and that is capable of pressing the input side rotating plate and the output side rotating plate, the input side rotating plate is provided so as to be displaceable along the axial direction of the clutch housing and to be rotatable integrally with the clutch housing, The pressure plate is The main body, a flange extending radially outward from an outer periphery of the body; a plurality of pressure side fitting teeth formed on the flange, holding the input side rotating plate and the output side rotating plate, and arranged in a circumferential direction; The flange is a pressing surface for applying a pressing force to the input side rotating plate and the output side rotating plate; a fitting tooth forming surface located radially inward from the pressing surface and located between adjacent pressure side fitting teeth; a connection surface located between the main body and the pressure side fitting teeth in a radial direction and formed continuously over the entire circumferential direction of the pressure plate, A clutch device, wherein the pressing surface and the mating tooth forming surface are continuous, the mating tooth forming surface and the connecting surface are continuous, and the pressing surface, the mating tooth forming surface and the connecting surface are formed to be approximately flush with each other.

2. 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 rotating plates that are rotationally driven by the rotational drive of the input shaft, holds a plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and 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 and that is capable of pressing the input side rotating plate and the output side rotating plate, the input side rotating plate is provided so as to be displaceable along the axial direction of the clutch housing and to be rotatable integrally with the clutch housing, The clutch center is an output shaft holding portion to which the output shaft is connected; an outer circumferential wall located radially outward of the output shaft holding portion; a plurality of center side fitting teeth arranged in a circumferential direction, the center side fitting teeth being arranged to hold the input side rotating plate and the output side rotating plate and protruding radially outward from an outer circumferential surface of the outer circumferential wall; a plurality of spline grooves formed between adjacent center side fitting teeth; an oil drain hole formed in the spline groove so as to penetrate the outer peripheral wall and draining clutch oil flowing along an inner peripheral surface side of the outer peripheral wall to an outside of the clutch center; a center side fitting portion formed on an inner peripheral surface of the outer peripheral wall, a portion of the output side rotating plate is spline-fitted to the center side fitting teeth and the spline grooves, The pressure plate is The main body, a flange extending radially outward from an outer periphery of the body; a plurality of pressure side fitting teeth that are formed on the flange, hold the input side rotating plate and the output side rotating plate, and are arranged in a circumferential direction; a pressure side fitting portion provided on the main body and slidably fitted into the center side fitting portion; a pressure-side assist cam surface that generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase a pressing force between the input side rotating plate and the output side rotating plate when the pressure plate rotates relative to the clutch center, The flange is a pressing surface for applying a pressing force to the input side rotating plate and the output side rotating plate; a fitting tooth forming surface located radially inward from the pressing surface and located between adjacent pressure side fitting teeth, The pressing surface and the engaging teeth forming surface are formed to be substantially flush with each other, when 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, the pressure-side fitting portion is located on the second direction side of the pressure-side assist cam surface, The oil discharge hole is provided at a position facing the pressure side fitting portion.

3. 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 rotating plates that are rotationally driven by the rotational drive of the input shaft, holds a plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and 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 and that is capable of pressing the input side rotating plate and the output side rotating plate, the input side rotating plate is provided so as to be displaceable along the axial direction of the clutch housing and to be rotatable integrally with the clutch housing, The clutch center is an output shaft holding portion to which the output shaft is connected; an outer circumferential wall located radially outward of the output shaft holding portion; a plurality of center side fitting teeth arranged in a circumferential direction, the center side fitting teeth being arranged to hold the input side rotating plate and the output side rotating plate and protruding radially outward from an outer circumferential surface of the outer circumferential wall; a plurality of spline grooves formed between adjacent center side fitting teeth; an oil drain hole formed in the spline groove so as to penetrate the outer peripheral wall and draining clutch oil flowing along an inner peripheral surface side of the outer peripheral wall to an outside of the clutch center; a center side fitting portion formed on an inner peripheral surface of the outer peripheral wall, a portion of the output side rotating plate is spline-fitted to the center side fitting teeth and the spline grooves, The pressure plate is The main body, a flange extending radially outward from an outer periphery of the body; a plurality of pressure side fitting teeth that are formed on the flange, hold the input side rotating plate and the output side rotating plate, and are arranged in a circumferential direction; a pressure side fitting portion provided on the main body and slidably fitted into the center side fitting portion; a pressure-side assist cam surface that generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase a pressing force between the input side rotating plate and the output side rotating plate when the pressure plate rotates relative to the clutch center, The flange is a mating tooth forming surface located between adjacent pressure side mating teeth; a connection surface located between the body and the pressure side fitting teeth in a radial direction, The engaging teeth forming surface and the connecting surface are formed to be substantially flush with each other, when 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, the pressure-side fitting portion is located on the second direction side of the pressure-side assist cam surface, The oil discharge hole is provided at a position facing the pressure side fitting portion.

4. A motorcycle comprising the clutch device according to claim 1.

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