Clutch device

Abstract

In the clutch device 210, the pressure side cam portion 260 has a first corner portion 291 that defines the opening end of the pressure side cam hole 273H on the second direction D2 side and is located on one side of the pressure side cam hole 273H in the circumferential direction S of the pressure plate 270, and a second corner portion 292 that defines the opening end of the pressure side cam hole 273H on the second direction D2 side and is located on the other side of the pressure side cam hole 273H in the circumferential direction S, and the first corner portion 291 has an R-chamfered shape and the second corner portion 292 has a pin-angle shape.

Description

[Technical Field]

[0001] The present invention relates to a clutch device. [Background technology]

[0002] Conventionally, vehicles such as motorcycles have been equipped with clutch devices. For example, Patent Document 1 discloses a clutch device including a clutch center that holds a portion of an output rotating plate, and a pressure plate that is arranged to be able to approach and move away from the clutch center and that holds a portion of the output rotating plate. The clutch center and the pressure plate each include an annular outer peripheral wall and a plurality of engaging teeth that protrude radially outward from the outer peripheral surface of the outer peripheral wall, and the output rotating plate is held by the engaging teeth.

[0003] Furthermore, the clutch center and pressure plate of the clutch device of Patent Document 1 are each equipped with a center-side assist cam surface and a pressure-side assist cam surface that generate 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-204655 Summary of the Invention [Problem to be solved by the invention]

[0005] In a clutch device having a center-side assist cam surface and a pressure-side assist cam surface, the center-side assist cam surface and the pressure-side assist cam surface frequently come into contact with each other. For this reason, it is desirable to effectively supply clutch oil to the center-side assist cam surface and the pressure-side assist cam surface in order to suppress wear on the center-side assist cam surface and the pressure-side assist cam surface and the generation of abnormal noise when they come into contact.

[0006] The present invention has been made in consideration of the above points, and its object is to provide a clutch device that can effectively supply clutch oil to the center side assist cam surface or the pressure side assist cam surface. [Means for solving the problem]

[0007] A clutch device according to the present invention is a clutch device that transmits or cuts off 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 is rotationally driven together with the output shaft; a pressure plate that is provided so as to be able to approach and move away from the clutch center, that holds at least some of the plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and that is able to press the input side rotating plates and the output side rotating plates; and a stopper plate that is fixed to the clutch center and 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 by more than a predetermined distance in the second direction, when the direction in which the pressure plate approaches and moves away from the clutch center is defined as a movement direction, the direction in which the pressure plate approaches the clutch center is defined as a first direction, and the direction in which the pressure plate moves away from the clutch center is defined as a second direction, and the pressure plate a pressure-side cam portion having a pressure-side assist cam surface that generates a force in a direction from the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotary plate and the output-side rotary plate when the pressure plate rotates relative to the clutch center, and a pressure-side slipper cam surface that separates the pressure plate from the clutch center in order to decrease the pressing force between the input-side rotary plate and the output-side rotary plate; and a plurality of pressure-side cam holes that are formed between adjacent pressure-side cam portions, and In terms of appearance, at least a portion of the pressure-side assist cam surface overlaps with the pressure-side cam hole, and the pressure-side cam portion has a first corner portion that defines the opening end of the pressure-side cam hole on the second direction side and is located on one side of the pressure-side cam hole in the circumferential direction of the pressure plate, and a second corner portion that defines the opening end of the pressure-side cam hole on the second direction side and is located on the other side of the pressure-side cam hole in the circumferential direction, and the first corner portion has an R-chamfered shape and the second corner portion has a pin-angle shape.

[0008] In the clutch device according to the present invention, the pressure-side cam portion has a first corner that defines the opening end of the pressure-side cam hole on the second direction side and is located on one side of the pressure-side cam hole in the circumferential direction of the pressure plate, and a second corner that defines the opening end of the pressure-side cam hole on the second direction side and is located on the other side of the pressure-side cam hole in the circumferential direction, the first corner having a rounded chamfered shape and the second corner having a pin-shaped corner. According to the above aspect, when the pressure plate rotates and clutch oil flows around the opening end of the pressure-side cam hole on the second direction side, the first corner has a rounded chamfered shape and can be guided by the first corner to be supplied into the pressure-side cam hole, and the second corner has a pin-shaped corner, so that the clutch oil can be splashed from the second corner over a wider area of ​​the pressure-side cam hole. Here, when viewed from the axial direction of the output shaft, the pressure side assist cam surface and the pressure side cam hole overlap, so clutch oil can be effectively supplied to the pressure side assist cam surface via the first corner portion and the second corner portion.

[0009] Another clutch device according to the present invention is a clutch device that transmits or interrupts 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 is rotationally driven together with the output shaft; a pressure plate that is provided so as to be able to approach and move away from the clutch center, that holds at least some of a plurality of output side rotating plates that are arranged alternately with the input side rotating plates, and that is able to press the input side rotating plates and the output side rotating plates; and a stopper plate that is fixed to the pressure plate and is provided so as to be able to come into contact with the clutch center and that prevents the pressure plate from moving away from the clutch center by more than a predetermined distance in the second direction, when the direction in which the pressure plate approaches and moves away from the clutch center is defined as a movement direction, the direction in which the pressure plate approaches the clutch center is defined as a first direction, and the direction in which the pressure plate moves away from the clutch center is defined as a second direction. a plurality of center-side cam portions each having a center-side assist cam surface that generates a force in a direction from the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotary plate and the output-side rotary plate when the pressure plate rotates relative to the pressure plate, and a center-side slipper cam surface that separates the pressure plate from the clutch center in order to decrease the pressing force between the input-side rotary plate and the output-side rotary plate; and a plurality of center-side cam holes that are formed between adjacent center-side cam portions, When viewed in the axial direction of the output shaft, at least a portion of the center-side assist cam surface overlaps with the center-side cam hole, and the center-side cam portion has a first corner portion that defines the opening end of the center-side cam hole on the first direction side and is located on one side of the center-side cam hole in the circumferential direction of the clutch center, and a second corner portion that defines the opening end of the center-side cam hole on the first direction side and is located on the other side of the center-side cam hole in the circumferential direction, and the first corner portion has an R-chamfered shape and the second corner portion has a pin-angle shape.

[0010] In another clutch device according to the present invention, the center-side cam portion has a first corner that defines the opening end of the center-side cam hole on the first direction side and is located on one side of the center-side cam hole in the circumferential direction of the clutch center, and a second corner that defines the opening end of the center-side cam hole on the first direction side and is located on the other side of the center-side cam hole in the circumferential direction, the first corner having an R-chamfered shape and the second corner having a pin-angled shape. According to the above aspect, when the clutch center rotates and clutch oil flows around the opening end of the center-side cam hole on the first direction side, the R-chamfered shape of the first corner allows the clutch oil to be guided by the first corner and supplied into the center-side cam hole, and the pin-angle shape of the second corner allows the clutch oil to splash from the second corner over a wider area of ​​the center-side cam hole. Here, when viewed from the axial direction of the output shaft, the center side assist cam surface and the center side cam hole overlap, so clutch oil can be effectively supplied to the center side assist cam surface via the first corner portion and the second corner portion. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a clutch device that can effectively supply clutch oil to the center side assist cam surface or the pressure side assist cam surface. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view of a clutch device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the clutch center according to the first embodiment. [Figure 3] FIG. 3 is a plan view of the clutch center according to the first embodiment. [Figure 4] FIG. 4 is a perspective view of the clutch center according to the first embodiment. [Figure 5] FIG. 5 is a plan view of the clutch center according to the first embodiment. [Figure 6] FIG. 6 is a perspective view of the pressure plate according to the first embodiment. [Figure 7]FIG. 7 is a plan view of the pressure plate according to the first embodiment. [Figure 8] FIG. 8 is a perspective view of the pressure plate according to the first embodiment. [Figure 9] FIG. 9 is a plan view of the pressure plate according to the first embodiment. [Figure 10A] FIG. 10A is a schematic diagram illustrating the action of the center-side assist cam surface and the pressure-side assist cam surface. [Figure 10B] FIG. 10B is a schematic diagram illustrating the action of the center-side slipper cam surface and the pressure-side slipper cam surface. [Figure 11] FIG. 11 is a schematic diagram showing the positional relationship between the center-side annular portion and the pressure-side annular portion when viewed in the axial direction of the output shaft. [Figure 12] FIG. 12 is a plan view showing the clutch center and the pressure plate as viewed from the axial direction of the output shaft in a state in which the center-side assist cam surface and the pressure-side assist cam surface are in contact with each other. [Figure 13] FIG. 13 is a side view showing a state in which a part of the center-side protrusion overlaps with the pressure-side spline groove when viewed from the radial direction of the output shaft. [Figure 14] FIG. 14 is a side view showing a state in which a gap is formed between the center-side protrusion and the pressure plate when viewed from the radial direction of the output shaft. [Figure 15] FIG. 15 is a side view showing the relationship between the outermost output-side rotating plate and the center-side protrusion when viewed from the radial direction of the output shaft. [Figure 16] FIG. 16 is a side view showing a state in which a part of the pressure-side protrusion overlaps with the center-side spline groove when viewed from the radial direction of the output shaft. [Figure 17] FIG. 17 is a cross-sectional view of a clutch device according to the second embodiment. [Figure 18] FIG. 18 is a perspective view of the clutch center according to the second embodiment. [Figure 19] FIG. 19 is a plan view of the clutch center according to the second embodiment. [Figure 20] FIG. 20 is a perspective view of the clutch center according to the second embodiment. [Figure 21] FIG. 21 is a plan view of the clutch center according to the second embodiment. [Figure 22] FIG. 22 is a perspective view of a pressure plate according to the second embodiment. [Figure 23] FIG. 23 is a plan view of a pressure plate according to the second embodiment. [Figure 24] FIG. 24 is a perspective view of a pressure plate according to the second embodiment. [Figure 25] FIG. 25 is a plan view of a pressure plate according to the second embodiment. [Figure 26] FIG. 26 is a schematic diagram showing the positional relationship between the center-side annular portion and the pressure-side annular portion when viewed in the axial direction of the output shaft. [Figure 27] FIG. 27 is a schematic diagram showing the positional relationship between the center-side fitting teeth and the pressure-side fitting teeth when viewed in the axial direction of the output shaft. [Figure 28] FIG. 28 is a schematic diagram showing the positional relationship between the center-side fitting teeth and the pressure-side fitting teeth when viewed in the axial direction of the output shaft. [Figure 29] FIG. 29 is a schematic diagram showing the positional relationship between the center-side fitting teeth and the pressure-side fitting teeth when viewed in the axial direction of the output shaft. [Figure 30] FIG. 30 is a table showing the positional relationship between the center side fitting teeth and the pressure side fitting teeth when viewed from the axial direction of the output shaft. [Figure 31] FIG. 31 is a side view showing a state in which the center line of the center-side spline groove and the center line of the pressure-side spline groove are aligned on the same straight line when viewed from the radial direction of the output shaft. [Figure 32] FIG. 32 is a plan view showing the clutch center and the pressure plate as viewed from the axial direction of the output shaft in a state in which the center-side assist cam surface and the pressure-side assist cam surface are in contact with each other. [Figure 33]FIG. 33 is a side view showing a state in which a part of the pressure-side protrusion overlaps with the center-side spline groove when viewed from the radial direction of the output shaft. [Figure 34] FIG. 34 is a side view showing a state in which a gap is formed between the pressure-side protrusion and the clutch center when viewed from the radial direction of the output shaft. [Figure 35] FIG. 35 is a side view showing the relationship between the outermost output-side rotary plate and the pressure-side protrusion when viewed from the radial direction of the output shaft. [Figure 36] FIG. 36 is a side view showing a state in which a part of the center-side protrusion overlaps with the pressure-side spline groove when viewed from the radial direction of the output shaft. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of a clutch device according to the present invention will be described with reference to the drawings. It should be noted that the embodiment described here is not intended to limit the present invention in any particular way. Furthermore, the same reference numerals are used to designate members and parts that perform the same functions, and redundant descriptions will be omitted or simplified as appropriate.

[0014] 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 a power source such as 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.

[0015] 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, the direction in which the pressure plate 70 approaches the clutch center 40 is referred to as first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is referred to as second direction D2. Direction D is an example of a movement direction. The circumferential direction of the clutch center 40 and the pressure plate 70 is referred to as circumferential direction S, the direction from one side to the other in the circumferential direction S is referred to as first circumferential direction S1 (see FIG. 2), and the direction from the other side to the other is referred to as second circumferential direction S2 (see FIG. 2). 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. The pressure plate 70 and the clutch center 40 rotate in the first circumferential direction S1. However, the above directions are merely defined for the convenience of explanation, and do not limit the installation mode of the clutch device 10 or the present invention in any way.

[0016] 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.

[0017] As shown in Fig. 1, the output shaft 15 is a hollow shaft body. One end of the output shaft 15 rotatably supports an input gear 35 and a clutch housing 30 (described later) via a bearing 15A. The output shaft 15 fixedly supports a clutch center 40 via a washer 15D and a nut 15N. 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] 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 direction D 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 the 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 as the input shaft of the engine rotates. The input gear 35 rotates 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 the side wall 33 of the clutch housing 30. The input side rotating plate 20 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. The input side rotating plate 20 is provided so as to be displaceable along the axial direction of the clutch housing 30 (i.e., direction D). 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 that is pressed against the output side rotating plate 22. The input side rotating plate 20 is formed in an annular shape. The input side rotating plate 20 is formed by aluminum die-casting. Friction material (not shown) made of multiple pieces of paper is attached to the front and back surfaces of the input side rotating plate 20. Grooves several hundred microns 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 disposed concentrically with the clutch housing 30. The clutch center 40 has a cylindrical main body 42 and a center-side flange 68 extending radially outward from the outer peripheral edge of the main body 42. The main body 42 protrudes in the second direction D2 beyond the center-side flange 68. The clutch center 40 holds the input-side rotating plate 20 and some of 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 Figure 2, the main body 42 includes an output shaft holding portion 50 provided in the center of the main body 42, a center side outer peripheral wall 45 located radially outward from the output shaft holding portion 50, and a plurality of center side cam portions 60 connected to the output shaft holding portion 50 and the center side outer peripheral wall 45.

[0024] 2 and 3, the center-side flange 68 extends radially outward from the outer peripheral edge of the main body 42. The center-side flange 68 is located radially outward of the center-side cam portion 60. The center-side flange 68, together with a pressure-side flange 98 (described later) of the pressure plate 70, sandwiches the input-side rotating plate 20 and the output-side rotating plate 22. The center-side flange 68 is provided so as to be able to press the input-side rotating plate 20 and the output-side rotating plate 22. The center-side flange 68 is a member that applies a pressing force to the input-side rotating plate 20 and the output-side rotating plate 22.

[0025] As shown in FIG. 2, the output shaft holding portion 50 is formed in a cylindrical shape. The output shaft holding portion 50 extends in direction D. An end portion of the output shaft holding portion 50 on the second direction D2 side is located closer to the second direction D2 than the center-side cam portion 60. An insertion hole 51 is formed through the output shaft holding portion 50, into which the output shaft 15 is inserted and spline-fitted. 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 Figures 2 and 3, the center-side outer peripheral wall 45 is formed in an annular shape extending in direction D. A center-side spline fitting portion 46 is provided on the outer peripheral surface 45A of the center-side outer peripheral wall 45. The center-side 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 center-side outer peripheral wall 45, and a plurality of center-side spline grooves 48 formed between adjacent center-side fitting teeth 47 and extending in the axial direction of the clutch center 40. The center-side fitting teeth 47 hold the output-side rotating plate 22. The center-side fitting teeth 47 are aligned 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 center-side outer peripheral wall 45. When viewed from the axial direction of the output shaft 15, the center-side fitting teeth 47 are formed by both side surfaces 47S in the circumferential direction S and a top surface 47Q connecting the radially outer ends of both side surfaces 47S. The multiple center-side spline grooves 48 are aligned in the circumferential direction S. The multiple center-side spline grooves 48 are formed at equal intervals in the circumferential direction S. The multiple center-side spline grooves 48 are formed to have the same shape. When viewed from the axial direction of the output shaft 15, the center-side spline grooves 48 are formed by the side surfaces 47S in the circumferential direction S of adjacent center-side fitting teeth 47 and the outer peripheral surface 45A of the center-side outer peripheral wall 45. An oil circulation hole 45F is provided in the center-side outer peripheral wall 45, penetrating in the radial direction. The oil circulation holes 45F communicate with the center side spline grooves 48.

[0027] As shown in FIGS. 2 and 3, the clutch center 40 includes a plurality of center-side protrusions 41. The center-side protrusions 41 are provided at the end 47D2 of the center-side fitting tooth 47 in the second direction D2. The center-side protrusions 41 extend in the second direction D2 from the end 47D2 in the second direction D2. The center-side protrusions 41 and the center-side fitting tooth 47 are integrally formed. The plurality of center-side protrusions 41 are aligned in the circumferential direction S. The plurality of center-side protrusions 41 are formed at equal intervals in the circumferential direction S. The plurality of center-side protrusions 41 are formed to have the same shape. Here, the center-side protrusions 41 include, for example, a first center-side protrusion 41A and a second center-side protrusion 41B. The length of the first center-side protrusion 41A in the direction D is the same as the length of the second center-side protrusion 41B in the direction D. The length of the first center-side protrusion 41A in direction D and the length of the second center-side protrusion 41B in direction D may be different. Also, the clutch center 40 includes three center-side protrusions 41, but may include two center-side protrusions 41, four or more center-side protrusions 41, or one center-side protrusion 41.

[0028] The output side rotating plate 22 is held by a center side spline fitting portion 46 of the clutch center 40 and a pressure side spline fitting portion 76 of the pressure plate 70, which will be described later. A portion of the output side rotating plate 22 is held by spline fitting to center side fitting teeth 47 and center side spline grooves 48 of the clutch center 40. Another portion of the output side rotating plate 22 is held by spline fitting to pressure side fitting teeth 77 (see Figures 6 and 7) and pressure side spline grooves 78 (see Figures 6 and 7), which will be described later, of the pressure plate 70. 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.

[0029] The output side rotating plate 22 is a member that is pressed against the input side rotating plate 20. The output side rotating plate 22 is formed in an annular shape. The output side rotating plate 22 is formed by punching out an annular shape from a thin plate material made of SPCC material. 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.

[0030] The center-side cam portion 60 is formed in a platform shape with a cam surface made of an inclined surface that constitutes 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 quickly separates the input-side rotating plate 20 and the output-side rotating plate 22, resulting in a transition to a partial clutch state. The partial clutch state is a state between a clutch-engaged state and a clutch-disengaged state. The center-side cam portion 60 is formed on the main body 42. An end of the center-side cam portion 60 on the second direction D2 side is located closer to the second direction D2 than the center-side outer peripheral wall 45. The center-side cam portions 60 are arranged at equal intervals in the circumferential direction S of the clutch center 40. In this embodiment, the clutch center 40 has three center-side cam portions 60, but the number of center-side cam portions 60 is not limited to three.

[0031] As shown in FIG. 2, 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 (see also FIGS. 4 and 5) and a center-side slipper cam surface 60S. The center-side assist cam surface 60A is configured to generate a force (here, a first direction D1) from the pressure plate 70 toward the clutch center 40 when the clutch center 40 rotates relative to the pressure plate 70 during acceleration or other such events in order to increase the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22. In this embodiment, when the 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 the clutch center 40 rotates relative to the pressure plate 70 during deceleration, etc. 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 arranged opposite each other in the circumferential direction S.

[0032] As shown in FIGS. 4 and 5, the center-side cam portion 60 has a first corner 61 and a second corner 62. The first corner 61 defines the opening end of the center-side cam hole 43H on the first direction D1 side, and is located on one side of the center-side cam hole 43H in the circumferential direction S of the clutch center 40 (here, the first circumferential direction S1 side). The first corner 61 is located on the center-side assist cam surface 60A side. The first corner 61 has a so-called R-chamfered shape with a rounded corner. The second corner 62 defines the opening end of the center-side cam hole 43H on the first direction D1 side, and is located on the other side of the center-side cam hole 43H in the circumferential direction S of the clutch center 40 (here, the second circumferential direction S2 side). The second corner 62 is located on the center-side slipper cam surface 60S side. The second corner 62 has a so-called pin-angle shape with a pointed tip.

[0033] As shown in FIGS. 3 and 5, the clutch center 40 has a center-side cam hole 43H penetrating a portion of the main body 42. The center-side cam hole 43H penetrates the main body 42 in direction D. The center-side cam hole 43H extends from a radially outer portion of the output shaft holding portion 50 to the center-side outer peripheral wall 45. The center-side cam hole 43H is formed between the center-side assist cam surface 60A and the center-side slipper cam surface 60S of the adjacent center-side cam portion 60. The center-side cam hole 43H has a first portion 43H1 located on the center-side assist cam surface 60A side and a second portion 43H2 located on the center-side slipper cam surface 60S side. The radial length L1 of the first portion 43H1 is longer than the radial length L2 of the second portion 43H2. A boss portion 84 (see FIG. 1), which will be described later, of the pressure plate 70 is inserted into the center-side cam hole 43H. When viewed in the axial direction of the clutch center 40 (i.e., the axial direction of the output shaft 15), at least a portion of the center-side assist cam surface 60A overlaps with a portion of the center-side cam hole 43H.

[0034] As shown in Figures 2 to 5, the clutch center 40 has an inner diameter side step portion 65. The inner diameter side step portion 65 is formed on a radially outer surface 50J (see Figure 2) of the output shaft holding portion 50. The inner diameter side step portion 65 extends in direction D. The inner diameter side step portion 65 defines a part of the center side cam hole 43H. When viewed from the axial direction of the output shaft 15, a portion 65S2 of the inner diameter side step portion 65 located on the second circumferential direction S2 side is located radially outward of a portion 65S1 located on the first circumferential direction S1 side.

[0035] As shown in Figures 2 to 5, the clutch center 40 has an outer diameter side step portion 66. The outer diameter side step portion 66 is formed on a radially inner surface 45P (see Figure 4) of the center side outer peripheral wall 45. The outer diameter side step portion 66 extends in direction D. The outer diameter side step portion 66 defines a part of the center side cam hole 43H. When viewed in the axial direction of the output shaft 15, a portion 66S2 of the outer diameter side step portion 66 located on the second circumferential direction S2 side is located radially inward of a portion 66S1 located on the first circumferential direction S1 side.

[0036] As shown in FIGS. 4 and 5 , the clutch center 40 includes a spring accommodating portion 54. The spring accommodating portion 54 is an example of an accommodating portion. The spring accommodating portion 54 is recessed from the first direction D1 toward the second direction D2. The spring accommodating portion 54 is formed in the main body 42. More specifically, the spring accommodating portion 54 is formed in the center-side cam portion 60. The spring accommodating portion 54 accommodates the clutch spring 25 (see FIG. 1 ). In this embodiment, the clutch center 40 includes three spring accommodating portions 54. The three spring accommodating portions 54 are disposed at equal intervals in the circumferential direction S of the clutch center 40. The number of spring accommodating portions 54 is not limited to three. The spring accommodating portion 54 is located closer to the second circumferential direction S2 than the center-side slipper cam surface 60S. The spring accommodating portion 54 is located closer to the first circumferential direction S1 than the first corner portion 61. The spring accommodating portion 54 is located closer to the first circumferential direction S1 than the center-side assist cam surface 60A. The spring accommodating portion 54 has a bottom wall portion 54A that comes into contact with the end portion 25D2 of the clutch spring 25 in the second direction D2. As shown in FIG. 5 , the length 43SL of the center-side cam hole 43H in the circumferential direction S is longer than the length 54SL of the spring accommodating portion 54 in the circumferential direction S. The center-side protrusion 41 is located radially outward of the spring accommodating portion 54. The center-side protrusion 41 is located radially outward of the outer diameter side end portion 54T of the spring accommodating portion 54.

[0037] 1, the clutch spring 25 is housed in the spring housing 54. The clutch spring 25 biases the pressure plate 70 in a direction toward the clutch center 40 with respect to direction D (i.e., the first direction D1). The clutch spring 25 is, for example, a coil spring formed by spirally winding spring steel.

[0038] As shown in Figures 4 and 5, the clutch center 40 has a recess 99 formed in the center-side flange 68. The recess 99 is located radially outward of the spring accommodating portion 54. The recess 99 is recessed from the first direction D1 toward the second direction D2. For example, the recess 99 is recessed by 0.1 mm or more and 0.5 mm or less from the surface on the first direction D1 side. The recess 99 may be recessed by more than 0 mm and less than 0.1 mm from the surface on the first direction D1 side. At least a portion of the center-side protrusion 41 is located radially between the spring accommodating portion 54 and the recess 99.

[0039] As shown in FIG. 1, the clutch center 40 is provided with a biasing member 68S. The biasing member 68S is, for example, a disc spring. The biasing member 68S is provided on the center-side flange 68. The biasing member 68S is provided so as to be able to come into contact with the output-side rotating plate 22 held by the center-side fitting teeth 47. The biasing member 68S is configured to attenuate the generated assist force in order to suppress a sudden increase in the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22 due to the assist force generated when the center-side assist cam surface 60A comes into contact with a pressure-side assist cam surface 90A (described later).

[0040] As shown in FIG. 1 , the pressure plate 70 is housed in the clutch housing 30. The pressure plate 70 is located between the clutch housing 30 and the clutch center 40. The pressure plate 70 is provided so as to be able to move toward and away from the clutch center 40. The pressure plate 70 is provided so as to be able to rotate relative to the clutch center 40. The pressure plate 70 is configured so as to be able to press the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 70 is disposed concentrically with the clutch center 40 and the clutch housing 30. As shown in FIG. 6 , the pressure plate 70 has a cylindrical main body 72 and a pressure side flange 98 that connects to the outer peripheral 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 pressure side flange 98. The pressure plate 70 holds at least some of the input side rotating plates 20 and the multiple output side rotating plates 22 that are arranged alternately.

[0041] As shown in Figures 6 and 7, the main body 72 comprises an annular base wall 73, a fitting hole 80 provided in the center of the base wall 73, a pressure side outer peripheral wall 75 located radially outside the base wall 73 and extending toward the first direction D1, and a plurality of pressure side cam portions 90 connected to the base wall 73 and the pressure side outer peripheral wall 75.

[0042] As shown in Figures 6 and 7, the pressure-side flange 98 extends radially outward from the outer peripheral edge of the main body 72. The pressure-side flange 98 is located radially outward of the pressure-side cam portion 90. The pressure-side flange 98, together with the center-side flange 68 of the clutch center 40, sandwiches the input-side rotating plate 20 and the output-side rotating plate 22. The pressure-side flange 98 is provided so as to be able to press the input-side rotating plate 20 and the output-side rotating plate 22. The pressure-side flange 98 is a member that applies a pressing force to the input-side rotating plate 20 and the output-side rotating plate 22.

[0043] As shown in Figures 6 and 7, the fitting hole 80 is formed in the center of the main body 72. The fitting hole 80 penetrates the base wall 73 in direction D. The output shaft holding portion 50 (see Figure 2) of the clutch center 40 is inserted into the fitting hole 80. The fitting hole 80 fits onto the output shaft holding portion 50.

[0044] As shown in Figures 6 and 7, the pressure-side outer peripheral wall 75 is formed in an annular shape extending in direction D. A pressure-side spline fitting portion 76 is provided on an outer peripheral surface 75A of the pressure-side outer peripheral wall 75. The pressure-side spline fitting portion 76 has a plurality of pressure-side fitting teeth 77 extending in the axial direction of the pressure plate 70 along the outer peripheral surface 75A of the pressure-side outer peripheral wall 75, and a plurality of pressure-side spline grooves 78 formed between adjacent pressure-side fitting teeth 77 and extending in the axial direction of the pressure plate 70. The pressure-side fitting teeth 77 hold the output-side rotating plate 22. The plurality of pressure-side fitting teeth 77 are aligned in the circumferential direction S. The plurality of pressure-side fitting teeth 77 are formed to have the same shape. The pressure-side fitting teeth 77 protrude radially outward from the outer peripheral surface 75A of the pressure-side outer peripheral wall 75. When viewed from the axial direction of the output shaft 15, the pressure-side fitted teeth 77 are formed by both side surfaces 77S in the circumferential direction S and a top surface 77Q connecting radially outer ends of the both side surfaces 77S. In this embodiment, when viewed from the axial direction of the output shaft 15, the pressure-side fitted teeth 77 and the center-side fitted teeth 47 have the same outer shape. The multiple pressure-side spline grooves 78 are aligned in the circumferential direction S. When viewed from the axial direction of the output shaft 15, the pressure-side spline grooves 78 are formed by the side surfaces 77S in the circumferential direction S of adjacent pressure-side fitted teeth 77 and the outer peripheral surface 75A of the pressure-side outer peripheral wall 75. The multiple pressure-side spline grooves 78 include first pressure-side spline grooves 78A that are long in the circumferential direction S and second pressure-side spline grooves 78B that are short in the circumferential direction S.

[0045] The pressure-side cam portion 90 is formed in a platform shape having a cam surface made up of an inclined surface that constitutes an Assist & Slipper (registered trademark) mechanism that slides on the center-side cam portion 60 to generate assist torque or slipper torque. The pressure-side cam portion 90 is formed so as to protrude in the first direction D1 beyond the pressure-side flange 98. As shown in FIG. 7 , the pressure-side cam portions 90 are arranged 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.

[0046] As shown in FIG. 6, the pressure-side cam portion 90 is located radially outward of the fitting hole 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also FIGS. 8 and 9) 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 from the pressure plate 70 toward 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 pressure plate 70 rotates relative to the clutch center 40 during acceleration, etc. 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 the pressure plate 70 rotates relative to the clutch center 40 during deceleration, etc. 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 arranged opposite each other in the circumferential direction S.

[0047] 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.

[0048] 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. As a result, 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, releasing the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22. This makes it possible to avoid problems with the engine and transmission due to back torque.

[0049] As shown in FIGS. 7 and 9, the pressure plate 70 has a pressure-side cam hole 73H penetrating a portion of the base wall 73. The pressure-side cam hole 73H penetrates the base wall 73 in direction D. The pressure-side cam hole 73H is located radially outward of the fitting hole 80. The pressure-side cam hole 73H extends from the side of the fitting hole 80 to the pressure-side outer peripheral wall 75. The pressure-side cam hole 73H is formed to penetrate between adjacent pressure-side cam portions 90. The pressure-side cam hole 73H is formed to penetrate between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 90. When viewed in the axial direction of the pressure plate 70 (i.e., the axial direction of the output shaft 15), at least a portion of the pressure-side assist cam surface 90A overlaps with a portion of the pressure-side cam hole 73H.

[0050] As shown in FIGS. 6 and 7 , the pressure plate 70 has a plurality of boss portions 84 (three in this embodiment). The plurality of boss portions 84 are arranged at equal intervals in the circumferential direction S. The boss portions 84 are formed in a cylindrical shape. The boss portions 84 are located radially outward from the fitting holes 80. The boss portions 84 extend from the base wall 73 in a first direction D1. The boss portions 84 are provided on the pressure-side cam portion 90. The boss portions 84 are located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S in the circumferential direction S. As shown in FIG. 1 , the boss portions 84 are inserted into the center-side cam hole 43H. A threaded hole 84H into which the bolt 28 is inserted is formed in the boss portion 84. The threaded hole 84H extends in the direction D.

[0051] As shown in FIG. 1 , the stopper plate 100 is provided so as to be able to come into contact with the clutch center 40. The stopper plate 100 is a member that prevents the pressure plate 70 from moving away from the clutch center 40 by more than a predetermined distance in the second direction D2. The stopper plate 100 is a member that displaces the pressure plate 70 in the direction D. An end 25D1 of the clutch spring 25 on the first direction D1 side comes into contact with the stopper plate 100. The stopper plate 100 is fixed to the pressure plate 70 by a bolt 28. The stopper plate 100 rotates integrally with the pressure plate 70. The stopper plate 100 moves in the direction D with respect to the clutch center 40 and rotates relatively to the clutch center 40. The stopper plate 100 is actuated by a clutch release mechanism (not shown). Here, the clutch release mechanism is a mechanical device that is actuated by the driver's operation of a clutch operating lever (not shown) in a vehicle such as a motorcycle equipped with the clutch device 10. The clutch release mechanism may also be electrically actuated by a servo motor or the like.

[0052] 11 , when viewed from the axial direction of the output shaft 15, at least a portion of the annular center-side annular portion 49 overlaps with the annular pressure-side annular portion 79. In this embodiment, the entire center-side annular portion 49 overlaps with the entire pressure-side annular portion 79. When viewed from the axial direction of the output shaft 15, the center-side annular portion 49 is a portion radially surrounded by a center-side tooth tip circle 49A passing through the tooth tip 47T (i.e., the top surface 47Q) located radially outermost among the center-side fitted teeth 47 and a center-side tooth root circle 49B passing through the tooth root 47B located radially innermost among the center-side fitted teeth 47. The tooth root 47B is continuous with the outer peripheral surface 45A of the center-side outer peripheral wall 45 and is located at the same position as the outer peripheral surface 45A in the radial direction. When viewed from the axial direction of the output shaft 15, the pressure-side annular portion 79 is a portion radially surrounded by a pressure-side tooth tip circle 79A passing through the tooth tips 77T (i.e., the top faces 77Q) located radially outermost among the pressure-side fitted teeth 77, and a pressure-side tooth bottom circle 79B passing through the tooth bottoms 77B located radially innermost among the pressure-side fitted teeth 77. The tooth bottoms 77B are continuous with the outer peripheral surface 75A of the pressure-side outer peripheral wall 75 and are at the same position in the radial direction as the outer peripheral surface 75A. In Figure 11, the center-side fitted teeth 47 and the center-side spline grooves 48 are indicated by dashed lines, and the pressure-side fitted teeth 77 and the pressure-side spline grooves 78 are indicated by solid lines. The positional relationship between the pressure side fitting teeth 77 and the center side fitting teeth 47 when viewed from the axial direction of the output shaft 15 and the positional relationship between the pressure side fitting teeth 77 and the center side fitting teeth 47 when viewed from the radial direction of the output shaft 15 are the same as the positional relationship between the pressure side fitting teeth 277 and the center side fitting teeth 247 according to the second embodiment described later (see Figures 26 to 29).

[0053] As shown in FIG. 12, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, as viewed from the axial direction of the output shaft 15 (for example, when viewed from the first direction D1 to the second direction D2), a first gap 87 is provided on the second circumferential direction S2 side of the end portion 60AS2 of the center-side assist cam surface 60A in the second circumferential direction S2. The first gap 87 penetrates the clutch center 40 and the pressure plate 70 in the direction D and overlaps with the pressure-side cam hole 73H. The first gap 87 is defined by the end portion 60AS2, the pressure-side cam portion 90, and the pressure-side bottom wall portion 73B. As shown in FIGS. 6 and 7, the pressure-side bottom wall portion 73B is a part of the base wall 73 and is located radially outward from the fitting hole 80. The pressure-side bottom wall portion 73B is located radially inward from the pressure-side cam portion 90. The pressure-side bottom wall portion 73B is located closer to the second direction D2 than the end portion 90D1 of the pressure-side cam portion 90 in the first direction D1.

[0054] 12, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, a recess 85 recessed in the second direction D2 is formed by the clutch center 40 and the pressure plate 70. The recess 85 is formed by a radially inner surface 90I of the pressure-side cam portion 90, a surface 73BD1 on the first direction D1 side of the pressure-side bottom wall portion 73B, and a radially outer surface 50J of the output shaft holding portion 50. The recess 85 is located closer to the second circumferential direction S2 than the first gap 87.

[0055] 12, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, a second gap 88 is provided radially outward of the center-side assist cam surface 60A when viewed in the axial direction of the output shaft 15. The second gap 88 passes through the clutch center 40 and the pressure plate 70 in direction D and overlaps with the pressure-side cam hole 73H. The second gap 88 is defined by the radially outer end 60AJ of the center-side assist cam surface 60A, the pressure-side cam portion 90, and the main body 42.

[0056] 13 , in at least a portion of the half-clutch state, at least a portion of the center-side protrusion 41 overlaps with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. In the entire half-clutch state, at least a portion of the center-side protrusion 41 may overlap with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. In the clutch-disengaged state, at least a portion of the center-side protrusion 41 may overlap with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. In at least a portion (e.g., all) of the state in which the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S are in contact with each other, at least a portion of the center-side protrusion 41 may overlap with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. In a state in which the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, at least a portion of the center-side protrusion 41 may overlap with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. In a state in which the clutch center 40 and the stopper plate 100 are in contact with each other, at least a portion of the center-side protrusion 41 may overlap with the pressure-side spline groove 78 when viewed from the radial direction of the output shaft 15. The state in which a portion of the center-side protrusion 41 overlaps with the pressure-side spline groove 78 shown in FIG. 13 can be one example of each of the above states.

[0057] As shown in FIG. 14 , when the clutch center 40 and the stopper plate 100 are in contact with each other, a gap 58 may be formed between the center-side protrusion 41 and the pressure plate 70 in the direction D when viewed from the radial direction of the output shaft 15. A length 58L of the gap 58 in the direction D is shorter than a length 22L (see FIG. 1 ) of the output-side rotating plate 22 in the direction D. As shown in FIG. 15 , when the pressure plate 70 is closest to the clutch center 40, among the output-side rotating plates 22 held by the center-side fitting teeth 47, the output-side rotating plate 22 located furthest in the second direction D2 is defined as the outermost output-side rotating plate 22X. When the clutch center 40 and the stopper plate 100 are in contact with each other, a surface 22XD1 on the first direction D1 side of the outermost output-side rotating plate 22X is located closer to the first direction D1 than an end 41D2 on the second direction D2 side of the center-side protrusion 41.

[0058] In the above-described embodiment, the clutch center 40 includes a plurality of center-side protrusions 41, and for example, when viewed from the radial direction of the output shaft 15, in at least a portion of the partial clutch state, at least a portion of the center-side protrusions 41 overlap with the pressure-side spline grooves 78. However, this is not limiting. As shown in FIG. 16 , for example, the pressure plate 70 may include a plurality of pressure-side protrusions 71, and for example, when viewed from the radial direction of the output shaft 15, in at least a portion of the partial clutch state, at least a portion of the pressure-side protrusions 71 may overlap with the center-side spline grooves 48. The pressure-side protrusions 71 are provided at the end 77D1 of the pressure-side fitting tooth 77 in the first direction D1. The pressure-side protrusions 71 extend in the first direction D1 from the end 77D1 in the first direction D1. The positional relationship between the pressure-side protrusion 71 and the center-side spline grooves 48 may be the same as the positional relationship between the center-side protrusion 41 and the pressure-side spline grooves 78 .

[0059] In the clutch device 10 of this embodiment, the center-side cam portion 60 has a first corner portion 61 that defines the opening end of the center-side cam hole 43H on the first direction D1 side and is located on one side of the center-side cam hole 43H in the circumferential direction S of the clutch center 40, and a second corner portion 62 that defines the opening end of the center-side cam hole 43H on the first direction D1 side and is located on the other side of the center-side cam hole 43H in the circumferential direction S, and the first corner portion 61 has an R-chamfered shape and the second corner portion 62 has a pin-angle shape. According to the above aspect, when the clutch center 40 rotates and clutch oil flows around the open end of the center-side cam hole 43H on the first direction D1 side, the first corner 61 has a rounded chamfered shape, so the clutch oil is guided by the first corner 61 and can be supplied into the center-side cam hole 43H, and the second corner 62 has a pin-angled shape, so the clutch oil can be scattered over a wider area of ​​the center-side cam hole 43H from the second corner 62. Here, the center-side assist cam surface 60A and the center-side cam hole 43H overlap when viewed in the axial direction of the output shaft 15, so clutch oil can be effectively supplied to the center-side assist cam surface 60A via the first corner 61 and the second corner 62.

[0060] In the clutch device 10 of this embodiment, the first corner 61 is located on the first circumferential direction S1 side of the center-side cam hole 43H, and the second corner 62 is located on the second circumferential direction S2 side of the center-side cam hole 43H. According to the above aspect, clutch oil can be more effectively supplied to the center-side assist cam surface 60A via the first corner 61 and the second corner 62.

[0061] In the clutch device 10 of this embodiment, the clutch center 40 is provided with a recess 99 that is formed in the center-side flange 68 so as to be located radially outward of the spring accommodating portion 54 and that is recessed from the first direction D1 to the second direction D2. According to the above aspect, the center-side flange 68 is provided with the recess 99 that is recessed from the first direction D1 to the second direction D2, which makes it possible to reduce the weight of the clutch center 40. Here, because the radially outer side of the spring accommodating portion 54 is already highly rigid due to the provision of the spring accommodating portion 54, the rigidity of the clutch center 40 can be ensured even when the recess 99 is provided.

[0062] In the clutch device 10 of this embodiment, the first corner 61 is located on the center-side assist cam surface 60A side, and the second corner 62 is located on the center-side slipper cam surface 60S side. According to the above aspect, when clutch oil flows around the open end of the center-side cam hole 43H on the first direction D1 side, the first corner 61 has an R-chamfered shape and is located on the center-side assist cam surface 60A side, so that the clutch oil can be guided by the first corner 61 and supplied to the center-side assist cam surface 60A. In addition, because the second corner 62 has a pin-angle shape, the clutch oil can be splashed toward the center-side assist cam surface 60A located on the opposite side of the center-side cam hole 43H from the second corner 62.

[0063] In the clutch device 10 of this embodiment, the length of the center-side cam hole 43H in the circumferential direction S is longer than the length of the spring accommodating portion 54 in the circumferential direction S. According to the above aspect, the length of the center-side cam hole 43H in the circumferential direction S is ensured to be longer than the length of the spring accommodating portion 54 in the circumferential direction S, so that clutch oil can be supplied to the center-side assist cam surface 60A through the center-side cam hole 43H.

[0064] Second Embodiment 17 is a cross-sectional view of a clutch device 210 according to a second embodiment. The clutch device 210 is provided on a vehicle such as a motorcycle. The clutch device 210 is a device that transmits or cuts off the rotational driving force of an input shaft (crankshaft) of an engine of a motorcycle to an output shaft 15, for example. The clutch device 210 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 210 is arranged between the engine and the transmission.

[0065] As shown in FIG. 17, the clutch device 210 includes an output shaft 15, an input side rotating plate 20, an output side rotating plate 22, a clutch housing 30, a clutch center 240, a pressure plate 270, and a stopper plate 300.

[0066] As shown in FIG. 17 , the output shaft 15 includes a hollow portion 15H, in which a push rod 16A is located, and a push member 16B is provided adjacent to the push rod 16A. The hollow portion 15H functions as a passage for clutch oil. The clutch oil flows through the output shaft 15, i.e., the hollow portion 15H. The push rod 16A and the push member 16B are slidably provided within 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 operating lever (not shown) of the motorcycle. When the clutch operating lever is operated, the push rod 16A slides within the hollow portion 15H and presses the push member 16B in the second direction D2. A portion of the push member 16B protrudes outward from the output shaft 15 (in this case, in the second direction D2) and is connected to a release bearing 18 provided on the pressure plate 270. The push rod 16A and the push member 16B are formed to have a smaller inner diameter than the hollow portion 15H, ensuring the flow of clutch oil within the hollow portion 15H.

[0067] As shown in FIG. 17, the clutch center 240 is accommodated in the clutch housing 30. The clutch center 240 is disposed concentrically with the clutch housing 30. As shown in FIG. 18, the clutch center 240 has a cylindrical main body 242 and a center-side flange 68 extending radially outward from the outer circumferential edge of the main body 242. The main body 242 protrudes in the second direction D2 beyond the center-side flange 68. The clutch center 240 holds the input-side rotating plate 20 and some of the multiple output-side rotating plates 22 arranged alternately in the direction D. The clutch center 240 is driven to rotate together with the output shaft 15.

[0068] As shown in Figure 18, the main body 242 includes an annular base wall 243, an output shaft holding portion 250 provided in the center of the base wall 243, a center side outer peripheral wall 245 located radially outside the base wall 243 and extending in the second direction D2, and a plurality of center side cam portions 260 connected to the base wall 243 and the center side outer peripheral wall 245.

[0069] 18, the output shaft holding portion 250 is formed in a cylindrical shape. The output shaft holding portion 250 extends in direction D. The end portion of the output shaft holding portion 250 on the second direction D2 side is located closer to the first direction D1 side than the center-side cam portion 260. The output shaft 15 is connected to the output shaft holding portion 250.

[0070] As shown in Figures 18 and 19, the center-side outer peripheral wall 245 is formed in an annular shape extending in direction D. A center-side spline fitting portion 246 is provided on an outer peripheral surface 245A of the center-side outer peripheral wall 245. The center-side spline fitting portion 246 has a plurality of center-side fitting teeth 247 extending in the axial direction of the clutch center 240 along the outer peripheral surface 245A of the center-side outer peripheral wall 245, and a plurality of center-side spline grooves 248 formed between adjacent center-side fitting teeth 247 and extending in the axial direction of the clutch center 240. The center-side fitting teeth 247 hold the output-side rotating plate 22. The plurality of center-side fitting teeth 247 are aligned in the circumferential direction S. The plurality of center-side fitting teeth 247 are formed in the same shape. The center-side fitting teeth 247 protrude radially outward from the outer peripheral surface 245A of the center-side outer peripheral wall 245. When viewed from the axial direction of the output shaft 15, the center-side fitting teeth 247 are formed by both side surfaces 247S in the circumferential direction S and a top surface 247Q connecting radially outer ends of the both side surfaces 247S. The multiple center-side spline grooves 248 are aligned in the circumferential direction S. The multiple center-side spline grooves 248 include first center-side spline grooves 248A that are long in the circumferential direction S and second center-side spline grooves 248B that are short in the circumferential direction S. When viewed from the axial direction of the output shaft 15, the center-side spline grooves 248 are formed by the side surfaces 247S in the circumferential direction S of adjacent center-side fitting teeth 247 and the outer peripheral surface 245A of the center-side outer peripheral wall 245.

[0071] The center-side cam portion 260 is formed in a platform shape having a cam surface made up of an inclined surface that constitutes the Assist & Slipper (registered trademark) mechanism. The center-side cam portion 260 is formed on the main body 242. An end portion of the center-side cam portion 260 on the second direction D2 side is flush with an end portion of the center-side outer peripheral wall 245 on the second direction D2 side. The center-side cam portions 260 are arranged at equal intervals in the circumferential direction S of the clutch center 240. In this embodiment, the clutch center 240 has three center-side cam portions 260, but the number of center-side cam portions 260 is not limited to three.

[0072] 18 and 19, the center-side cam portion 260 is located radially outward of the output shaft holding portion 250. The center-side cam portion 260 has a center-side assist cam surface 60A (see also FIGS. 20 and 21) and a center-side slipper cam surface 60S. In the center-side cam portions 260 adjacent to each other in the circumferential direction S, the center-side assist cam surface 60A of one center-side cam portion 260L and the center-side slipper cam surface 60S of the other center-side cam portion 260M are arranged opposite each other in the circumferential direction S.

[0073] As shown in Figures 19 and 21, the clutch center 240 has a center-side cam hole 243H that penetrates a portion of the base wall 243. The center-side cam hole 243H penetrates the base wall 243 in direction D. The center-side cam hole 243H is located radially outward of the output shaft holding portion 250. The center-side cam hole 243H extends from the radially outer portion of the output shaft holding portion 250 to the center-side outer peripheral wall 245. The center-side cam hole 243H is formed to penetrate between adjacent center-side cam portions 260. The center-side cam hole 243H is formed to penetrate between the center-side assist cam surface 60A and the center-side slipper cam surface 60S of adjacent center-side cam portions 260. When viewed in 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.

[0074] 18 and 19, the clutch center 240 has a plurality of boss portions 84 (three in this embodiment). The boss portions 84 are located radially outward from the output shaft holding portion 250. The boss portions 84 extend from the base wall 243 in the second direction D2. The boss portions 84 are provided on the center-side cam portion 260. As shown in FIG. 17, the boss portions 84 are inserted into the pressure-side cam hole 273H.

[0075] As shown in FIG. 17 , the pressure plate 270 is housed in the clutch housing 30. The pressure plate 270 is located closer to the clutch center 240 in the second direction D2. The pressure plate 270 is provided so as to be able to move toward or away from the clutch center 240 and to rotate relative to it. The pressure plate 270 is configured to be able to press the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 270 is disposed concentrically with the clutch center 240 and the clutch housing 30. As shown in FIG. 22 , the pressure plate 270 has a cylindrical main body 272 and a pressure side flange 98 that connects to the outer circumferential edge of the main body 272 on the second direction D2 side and extends radially outward. The main body 272 protrudes in the first direction D1 beyond the pressure side flange 98. The pressure plate 270 holds a portion of the plurality of output side rotating plates 22 that are arranged alternately with the input side rotating plates 20.

[0076] As shown in Figures 22 and 23, the main body 272 comprises a cylindrical portion 281, a fitting hole 282 provided in the cylindrical portion 281, a pressure side outer peripheral wall 275 located radially outward from the cylindrical portion 281 and extending in direction D, and a plurality of pressure side cam portions 290 located radially outward from the cylindrical portion 281 and connected to the pressure side outer peripheral wall 275.

[0077] As shown in Figures 22 and 23, the main body 272 is formed with a through hole 298 that penetrates in direction D. The through hole 298 is located radially outward from the pressure-side outer peripheral wall 275. The through hole 298 is located radially outward from the pressure-side slipper cam surface 90S. The through hole 298 is located radially inward from the pressure-side flange 98. The through hole 298 is located between adjacent pressure-side fitting teeth 277.

[0078] 22 and 23, the fitting hole 282 is provided at an open end of the cylindrical portion 281 on the first direction D1 side. The output shaft holding portion 250 of the clutch center 240 is inserted into the fitting hole 282. The output shaft holding portion 250 fits into the fitting hole 282. The cylindrical portion 281 is located radially outward of the output shaft holding portion 250 when the pressure plate 270 is assembled to the clutch center 240.

[0079] As shown in Figures 22 and 23, the pressure-side outer peripheral wall 275 is formed in an annular shape extending in direction D. A pressure-side spline fitting portion 276 is provided on an outer peripheral surface 275A of the pressure-side outer peripheral wall 275. The pressure-side 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 pressure-side outer peripheral wall 275, and a plurality of pressure-side spline grooves 278 formed between adjacent pressure-side fitting teeth 277 and extending in the axial direction of the pressure plate 270. The pressure-side fitting teeth 277 hold the output-side rotating plate 22. The multiple pressure-side fitting teeth 277 are aligned in the circumferential direction S. The multiple pressure-side fitting teeth 277 are formed to have the same shape. The pressure-side fitting teeth 277 protrude radially outward from the outer peripheral surface 275A of the pressure-side outer peripheral wall 275. When viewed from the axial direction of the output shaft 15, the pressure-side fitting teeth 277 are formed by both side surfaces 277S in the circumferential direction S and a top surface 277Q that connects the radially outer ends of the both side surfaces 277S. In this embodiment, when viewed from the axial direction of the output shaft 15, the pressure-side fitting teeth 277 and the center-side fitting teeth 247 have the same outer shape. The multiple pressure-side spline grooves 278 are aligned in the circumferential direction S. When viewed from the axial direction of the output shaft 15, the pressure-side spline grooves 278 are formed by the side surfaces 277S in the circumferential direction S of adjacent pressure-side fitting teeth 277 and the outer peripheral surface 275A of the pressure-side outer peripheral wall 275.

[0080] As shown in FIGS. 22 and 23, the pressure plate 270 includes a plurality of pressure-side protrusions 271. The pressure-side protrusions 271 are provided at the end 277D1 of the pressure-side fitting tooth 277 in the first direction D1. The pressure-side protrusions 271 extend in the first direction D1 from the end 277D1 in the first direction D1. The pressure-side protrusions 271 and the pressure-side fitting tooth 277 are integrally formed. The plurality of pressure-side protrusions 271 are aligned in the circumferential direction S. The plurality of pressure-side protrusions 271 are formed at equal intervals in the circumferential direction S. The plurality of pressure-side protrusions 271 are formed to have the same shape. Here, the pressure-side protrusions 271 include, for example, a first pressure-side protrusion 271A and a second pressure-side protrusion 271B. The length of the first pressure side protrusion 271A in direction D is the same as the length of the second pressure side protrusion 271B in direction D. Note that the length of the first pressure side protrusion 271A in direction D may be different from the length of the second pressure side protrusion 271B in direction D.

[0081] The pressure-side cam portion 290 is formed in a platform shape having a cam surface made up of an inclined surface that constitutes the Assist & Slipper (registered trademark) mechanism. The pressure-side cam portion 290 is formed so as to protrude in the first direction D1 beyond the pressure-side flange 98. The pressure-side cam portions 290 are arranged at equal intervals in the circumferential direction S of the pressure plate 270. In this embodiment, the pressure plate 270 has three pressure-side cam portions 290, but the number of pressure-side cam portions 290 is not limited to three.

[0082] 22 and 23, the pressure-side cam portion 290 is located radially outward of the cylindrical portion 281. The pressure-side cam portion 290 has a pressure-side assist cam surface 90A (see also FIGS. 24 and 25) and a pressure-side slipper cam surface 90S. In the pressure-side cam portions 290 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 290L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 290M are arranged opposite each other in the circumferential direction S.

[0083] As shown in FIGS. 24 and 25 , the pressure-side cam portion 290 has a first corner 291 and a second corner 292. The first corner 291 defines the opening end of the pressure-side cam hole 273H on the second direction D2 side, and is located on one side of the pressure-side cam hole 273H in the circumferential direction S of the pressure plate 270 (here, the second circumferential direction S2 side). The first corner 291 is located on the pressure-side assist cam surface 90A side. The first corner 291 has a so-called R-chamfered shape in which the corner is rounded. The second corner 292 defines the opening end of the pressure-side cam hole 273H on the second direction D2 side, and is located on the other side of the pressure-side cam hole 273H in the circumferential direction S of the pressure plate 270 (here, the first circumferential direction S1 side). The second corner 292 is located on the pressure-side slipper cam surface 90S side. The second corner 292 has a sharp tip, or a so-called pin-angle shape.

[0084] As shown in Figures 23 and 25, the pressure plate 270 has a pressure-side cam hole 273H that penetrates a portion of the main body 272. The pressure-side cam hole 273H penetrates the main body 272 in direction D. The pressure-side cam hole 273H is located radially outward of the fitting hole 282. The pressure-side cam hole 273H extends from the radially outer portion of the fitting hole 282 to the pressure-side outer peripheral wall 275. The pressure-side cam hole 273H is formed to penetrate between adjacent pressure-side cam portions 290. The pressure-side cam hole 273H is formed to penetrate between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 290. The pressure-side cam hole 273H has a first portion 273H1 located on the pressure-side assist cam surface 90A side and a second portion 273H2 located on the pressure-side slipper cam surface 90S side. The radial length LH1 of the first portion 273H1 is longer than the radial length LH2 of the second portion 273H2. When viewed from the axial direction of the pressure plate 270 (i.e., the axial direction of the output shaft 15), the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 273H overlap.

[0085] 22 to 25, the pressure plate 270 includes an inner diameter side step portion 295. The inner diameter side step portion 295 is formed on a radially outer surface 281J of the cylindrical portion 281. The inner diameter side step portion 295 extends in direction D. The inner diameter side step portion 295 defines a part of the pressure side cam hole 273H. When viewed from the axial direction of the output shaft 15, a portion 295S1 of the inner diameter side step portion 295 located on the first circumferential direction S1 side is located radially outward of a portion 295S2 located on the second circumferential direction S2 side.

[0086] As shown in FIGS. 22 to 25, the pressure plate 270 has an outer diameter side step portion 296. The outer diameter side step portion 296 is formed on the radially inner surface of the pressure side outer peripheral wall 275. The outer diameter side step portion 296 extends in direction D. The outer diameter side step portion 296 defines a part of the pressure side cam hole 273H. When viewed from the axial direction of the output shaft 15, a portion 296S1 of the outer diameter side step portion 296 located on the first circumferential direction S1 side is located radially inward of a portion 296S2 located on the second circumferential direction S2 side.

[0087] As shown in FIGS. 24 and 25 , the pressure plate 270 includes a spring accommodating portion 54. The spring accommodating portion 54 is an example of an accommodating portion. The spring accommodating portion 54 is recessed from the second direction D2 toward the first direction D1. The spring accommodating portion 54 is formed in the main body 272. More specifically, the spring accommodating portion 54 is formed in the pressure-side cam portion 290. In this embodiment, the pressure plate 270 includes three spring accommodating portions 54. The three spring accommodating portions 54 are disposed at equal intervals in the circumferential direction S of the pressure plate 270. The number of spring accommodating portions 54 is not limited to three. The spring accommodating portion 54 is located closer to the first circumferential direction S1 than the pressure-side slipper cam surface 90S. The spring accommodating portion 54 is located closer to the second circumferential direction S2 than the pressure-side assist cam surface 90A. The spring accommodating portion 54 is located closer to the second circumferential direction S2 than the first corner portion 291. A bottom wall portion 54A of the spring accommodating portion 54 contacts an end portion 25D1 of the clutch spring 25 in the first direction D1. A length 273SL of the pressure-side cam hole 273H in the circumferential direction S is longer than a length 54SL of the spring accommodating portion 54 in the circumferential direction S. The pressure-side protrusion 271 is located radially outward of the spring accommodating portion 54. The pressure-side protrusion 271 is located radially outward of an outer diameter side end portion 54T of the spring accommodating portion 54.

[0088] As shown in Figures 24 and 25, the pressure plate 270 has a recess 299 formed in the pressure-side flange 98. The recess 299 is located radially outward from the spring accommodating portion 54. The recess 299 is recessed from the second direction D2 toward the first direction D1. The recess 299 is recessed, for example, by 0.1 mm or more and 0.5 mm or less from the surface on the second direction D2 side. The recess 299 may be recessed by more than 0 mm and less than 0.1 mm from the surface on the second direction D2 side. At least a portion of the pressure-side protrusion 271 is located radially between the spring accommodating portion 54 and the recess 299.

[0089] As shown in Figure 17, the stopper plate 300 is provided so as to be able to come into contact with the pressure plate 270. The stopper plate 300 is a member that prevents the pressure plate 270 from moving away from the clutch center 240 in the second direction D2 by more than a predetermined distance. An end 25D2 of the clutch spring 25 on the second direction D2 side comes into contact with the stopper plate 300. The stopper plate 300 is fixed to the clutch center 240 by a bolt 28. The stopper plate 300 rotates integrally with the clutch center 240.

[0090] 26 , when viewed from the axial direction of the output shaft 15, at least a portion of the annular center-side annular portion 249 overlaps with the annular pressure-side annular portion 279. In this embodiment, the entire center-side annular portion 249 overlaps with the entire pressure-side annular portion 279. When viewed from the axial direction of the output shaft 15, the center-side annular portion 249 is a portion radially surrounded by a center-side tooth tip circle 249A passing through the tooth tip 247T (i.e., the top surface 247Q) located radially outermost among the center-side fitted teeth 247 and a center-side tooth bottom circle 249B passing through the tooth bottom 247B located radially innermost among the center-side fitted teeth 247. The tooth bottom 247B is continuous with the outer peripheral surface 245A of the center-side outer peripheral wall 245 and is located at the same position as the outer peripheral surface 245A in the radial direction. When viewed from the axial direction of the output shaft 15, the pressure-side annular portion 279 is a portion radially surrounded by a pressure-side tooth tip circle 279A passing through the tooth tip 277T (i.e., the top surface 277Q) located at the radially outermost position among the pressure-side fitted teeth 277 and a pressure-side tooth bottom circle 279B passing through the tooth bottom 277B located at the radially innermost position among the pressure-side fitted teeth 277. The tooth bottom 277B is continuous with the outer peripheral surface 275A of the pressure-side outer peripheral wall 275 and is at the same position in the radial direction as the outer peripheral surface 275A. In Figure 26, the center-side fitted teeth 247 and the center-side spline grooves 248 are indicated by dashed lines, and the pressure-side fitted teeth 277 and the pressure-side spline grooves 278 are indicated by solid lines.

[0091] 27 and 28, when viewed from the axial direction of the output shaft 15, at least a portion of the pressure-side fitting tooth 277 overlaps with the center-side fitting tooth 247. When viewed from the axial direction of the output shaft 15, at least a portion of the tooth tip 277T of the pressure-side fitting tooth 277 overlaps with the tooth tip 247T of the center-side fitting tooth 247. In the example shown in FIG. 27, when viewed from the axial direction of the output shaft 15, the entirety of one pressure-side fitting tooth 277 overlaps with the entirety of one center-side fitting tooth 247. When viewed from the axial direction of the output shaft 15, the entirety of the tooth tip 277T of one pressure-side fitting tooth 277 overlaps with the entirety of the tooth tip 247T of one center-side fitting tooth 247. When viewed from the axial direction of the output shaft 15, a center-side center line 247L passing through a center 247C in the circumferential direction S of the center-side fitting tooth 247 and a center 15C of the output shaft 15 overlaps with a pressure-side center line 277L passing through a center 277C in the circumferential direction S of the pressure-side fitting tooth 277 and the center 15C of the output shaft 15. In the example shown in FIG. 28 , when viewed from the axial direction of the output shaft 15, a portion of one pressure-side fitting tooth 277 overlaps with a portion of one center-side fitting tooth 247. When viewed from the axial direction of the output shaft 15, a portion of a tooth tip 277T of one pressure-side fitting tooth 277 overlaps with a portion of a tooth tip 247T of one center-side fitting tooth 247. 27 and 28, when viewed in the axial direction of the output shaft 15, at least a portion of the pressure-side spline grooves 278 overlaps with a center-side spline groove 248. In the example shown in Fig. 27, when viewed in the axial direction of the output shaft 15, the entirety of one pressure-side spline groove 278 overlaps with the entirety of one center-side spline groove 248. In the example shown in Fig. 28, when viewed in the axial direction of the output shaft 15, a portion of one pressure-side spline groove 278 overlaps with a portion of one center-side spline groove 248.

[0092] As shown in Figure 29, when viewed in the axial direction of the output shaft 15, the pressure-side fitting teeth 277 do not overlap with the center-side fitting teeth 247. In the example shown in Figure 29, when viewed in the axial direction of the output shaft 15, the entire tooth tip 277T of one pressure-side fitting tooth 277 does not overlap with the entire tooth tip 247T of one center-side fitting tooth 247. Also, as shown in Figure 29, when viewed in the axial direction of the output shaft 15, some of the multiple pressure-side spline grooves 278 do not overlap with the center-side spline grooves 248.

[0093] The positional relationship between the center-side fitting teeth 247 and the pressure-side fitting teeth 277 when viewed in the axial direction of the output shaft 15 varies depending on the relative positional relationship of the pressure plate 270 with respect to the clutch center 240. The positional relationship between the center-side fitting teeth 247 and the pressure-side fitting teeth 277 when viewed in the axial direction of the output shaft 15 can vary, for example, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A come into contact, in a partial clutch state, when the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S come into contact, and when the pressure plate 270 comes into contact with the stopper plate 300. 27 is defined as positional relationship 1, the positional relationship in FIG. 28 is defined as positional relationship 2, and the positional relationship in FIG. 29 is defined as positional relationship 3, the positional relationship between the center-side fitting teeth 247 and the pressure-side fitting teeth 277 when viewed from the axial direction of the output shaft 15 can be as shown in Fig. 30. As shown in Fig. 30, for example, in Example 1, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A come into contact, positional relationship 1 (Fig. 27) can be achieved, when the clutch is in a half-engaged state, positional relationship 3 (Fig. 29) can be achieved, when the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S come into contact, positional relationship 2 (Fig. 28) can be achieved, and when the pressure plate 270 comes into contact with the stopper plate 300, positional relationship 2 (Fig. 28) can be achieved.

[0094] In at least a portion of the range from when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact to when the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S are in contact, at least a portion of the pressure-side fitting tooth 277 may overlap with the center-side fitting tooth 247 when viewed in the axial direction of the output shaft 15. In a state where the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact, at least a portion of the pressure-side fitting tooth 277 may overlap with the center-side fitting tooth 247 when viewed in the axial direction of the output shaft 15. During the entire period from the state in which the center side assist cam surface 60A and the pressure side assist cam surface 90A come into contact to the state in which the center side slipper cam surface 60S and the pressure side slipper cam surface 90S come into contact, at least a portion of the pressure side engaging tooth 277 may overlap with the center side engaging tooth 247 when viewed from the axial direction of the output shaft 15.

[0095] In at least a portion of an operating state ranging from when the pressure plate 270 is closest to the clutch center 240 to when the pressure plate 270 is furthest from the clutch center 240, at least a portion of the pressure-side fitting teeth 277 may overlap with the center-side fitting teeth 247 when viewed in the axial direction of the output shaft 15. In all of an operating state ranging from when the pressure plate 270 is closest to the clutch center 240 to when the pressure plate 270 is furthest from the clutch center 240, at least a portion of the pressure-side fitting teeth 277 may overlap with the center-side fitting teeth 247 when viewed in the axial direction of the output shaft 15.

[0096] In at least a part of the partial clutch state, at least a part of the pressure-side fitting teeth 277 may overlap with the center-side fitting teeth 247 when viewed in the axial direction of the output shaft 15. In the entire partial clutch state, at least a part of the pressure-side fitting teeth 277 may overlap with the center-side fitting teeth 247 when viewed in the axial direction of the output shaft 15.

[0097] In a part of the range from when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact to when the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S are in contact, when viewed in the axial direction of the output shaft 15, a center-side center line 247L (see FIG. 27 ) passing through the center 247C in the circumferential direction S of the center-side fitted tooth 247 and the center 15C of the output shaft 15 may overlap with a pressure-side center line 277L passing through the center 277C in the circumferential direction S of the pressure-side fitted tooth 277 and the center 15C of the output shaft 15. In a state where the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact, when viewed in the axial direction of the output shaft 15, the center-side center line 247L may overlap with the pressure-side center line 277L.

[0098] As shown in Figure 31, in at least a portion of the operating state ranging from when the pressure plate 270 is closest to the clutch center 240 to when the pressure plate 270 is farthest from the clutch center 240, when viewed from the radial direction of the output shaft 15, the center line 248C of the center side spline groove 248 extending in the axial direction of the output shaft 15 and the center line 278C of the pressure side spline groove 278 extending in the axial direction of the output shaft 15 are positioned on the same straight line, and when viewed from the axial direction of the output shaft 15, the radially inner surface 248G of the center side spline groove 248 and the radially inner surface 278G of the pressure side spline groove 278 are positioned on the same plane (see Figure 27).

[0099] As shown in FIG. 32, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, as viewed from the axial direction of the output shaft 15 (for example, when viewed from the second direction D2 to the first direction D1), a first gap 287 is provided on the first circumferential direction S1 side of the end 90AS1 of the pressure-side assist cam surface 90A in the first circumferential direction S1. The first gap 287 penetrates the clutch center 240 and the pressure plate 270 in the direction D and overlaps with the center-side cam hole 243H. The first gap 287 is defined by the end 90AS1, the center-side cam portion 260, and the center-side bottom wall portion 243B. As shown in FIGS. 18 and 19, the center-side bottom wall portion 243B is a part of the base wall 243 and is located radially outward from the output shaft holding portion 250 and radially inward from the center-side cam portion 260. The center-side bottom wall portion 243B is located closer to the first direction D1 than the end portion 260D2 of the center-side cam portion 260 in the second direction D2.

[0100] 32, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, a recess 285 recessed in the first direction D1 is formed by the clutch center 240 and the pressure plate 270. The recess 285 is formed by a radially inner surface 260I of the center-side cam portion 260, a surface 243BD2 on the second direction D2 side of the center-side bottom wall portion 243B, and a radially outer surface 281J of the cylindrical portion 281. The recess 285 is located closer to the first circumferential direction S1 than the first gap 287.

[0101] 32, when the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, a second gap 288 is provided radially outward of the pressure-side assist cam surface 90A when viewed from the axial direction of the output shaft 15. The second gap 288 passes through the clutch center 240 and the pressure plate 270 in direction D and overlaps with the center-side cam hole 243H. The second gap 288 is defined by the radially outer end 90AJ of the pressure-side assist cam surface 90A, the center-side cam portion 260, and the main body 272.

[0102] 33 , in at least a part of the half-clutch state, at least a part of the pressure-side protrusion 271 overlaps with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. In the entire half-clutch state, at least a part of the pressure-side protrusion 271 may overlap with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. In the clutch-disengaged state, at least a part of the pressure-side protrusion 271 may overlap with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. In at least a part (for example, all) of the state in which the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S are in contact with each other, at least a part of the pressure-side protrusion 271 may overlap with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. In a state where the center-side assist cam surface 60A and the pressure-side assist cam surface 90A are in contact with each other, at least a portion of the pressure-side protrusion 271 may overlap with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. In a state where the pressure plate 270 and the stopper plate 300 are in contact with each other, at least a portion of the pressure-side protrusion 271 may overlap with the center-side spline groove 248 when viewed from the radial direction of the output shaft 15. Note that the state shown in FIG. 33 where a portion of the pressure-side protrusion 271 overlaps with the center-side spline groove 248 may be one example of each of the above states.

[0103] 34, when viewed from the radial direction of the output shaft 15, in a state where the pressure plate 270 and the stopper plate 300 are in contact with each other, a gap 258 may be formed between the pressure-side protrusion 271 and the clutch center 240 in direction D. A length 258L of the gap 258 in direction D is shorter than a length 22L of the output-side rotating plate 22 in direction D (see FIG. 17). As shown in Figure 35, when the pressure plate 270 is closest to the clutch center 240, and the output side rotating plate 22 held by the pressure side protrusion 271 and located furthest in the first direction D1 is the outermost output side rotating plate 22X, when the pressure plate 270 and the stopper plate 300 are in contact with each other, the surface 22XD2 on the second direction D2 side of the outermost output side rotating plate 22X is located closer to the second direction D2 than the end 271D1 on the first direction D1 side of the pressure side protrusion 271.

[0104] In the above-described embodiment, the pressure plate 270 includes a plurality of pressure-side protrusions 271, and for example, in at least a portion of the partial clutch state, when viewed from the radial direction of the output shaft 15, at least a portion of the pressure-side protrusions 271 overlap with the center-side spline grooves 248. However, this is not limiting. For example, the clutch center 240 may include a plurality of center-side protrusions 241, and as shown in FIG. 36, for example, in at least a portion of the partial clutch state, when viewed from the radial direction of the output shaft 15. The center-side protrusions 241 are provided at the end 247D2 of the center-side fitted tooth 247 in the second direction D2. The center-side protrusions 241 extend in the second direction D2 from the end 247D2 in the second direction D2. The positional relationship between the center-side protrusion 241 and the pressure-side spline grooves 278 may be the same as the positional relationship between the pressure-side protrusion 271 and the center-side spline grooves 248 .

[0105] As described above, according to the clutch device 210 of this embodiment, the pressure side cam portion 290 has a first corner portion 291 that defines the opening end of the pressure side cam hole 273H on the second direction D2 side and is located on one side of the pressure side cam hole 273H in the circumferential direction S of the pressure plate 270, and a second corner portion 292 that defines the opening end of the pressure side cam hole 273H on the second direction D2 side and is located on the other side of the pressure side cam hole 273H in the circumferential direction S, and the first corner portion 291 has an R-chamfered shape and the second corner portion 292 has a pin-angle shape. According to the above aspect, when the pressure plate 270 rotates and clutch oil flows around the open end of the pressure-side cam hole 273H on the second direction D2 side, the first corner 291 has a rounded chamfered shape, so that the clutch oil is guided by the first corner 291 and supplied into the pressure-side cam hole 273H, and the second corner 292 has a pin-angled shape, so that the clutch oil can be scattered over a wider area of ​​the pressure-side cam hole 273H from the second corner 292. Here, the pressure-side assist cam surface 90A and the pressure-side cam hole 273H overlap when viewed from the axial direction of the output shaft 15, so that the clutch oil can be effectively supplied to the pressure-side assist cam surface 90A via the first corner 291 and the second corner 292.

[0106] In the clutch device 210 of this embodiment, the first corner 291 is located on the second circumferential direction S2 side of the pressure-side cam hole 273H, and the second corner 292 is located on the first circumferential direction S1 side of the pressure-side cam hole 273H. According to the above aspect, clutch oil can be more effectively supplied to the pressure-side assist cam surface 90A via the first corner 291 and the second corner 292.

[0107] In the clutch device 210 of this embodiment, the pressure plate 270 is provided with a recess 299 that is formed in the pressure-side flange 98 so as to be located radially outward of the spring accommodating portion 54 and that recesses from the second direction D2 to the first direction D1. According to the above aspect, the pressure-side flange 98 is provided with the recess 299 that recesses from the second direction D2 to the first direction D1, which makes it possible to reduce the weight of the pressure plate 270. Here, because the radially outer side of the spring accommodating portion 54 is already highly rigid due to the provision of the spring accommodating portion 54, the rigidity of the pressure plate 270 can be ensured even when the recess 299 is provided.

[0108] In the clutch device 210 of this embodiment, the first corner 291 is located on the pressure-side assist cam surface 90A side, and the second corner 292 is located on the pressure-side slipper cam surface 90S side. According to the above aspect, when clutch oil flows around the opening end of the pressure-side cam hole 273H on the second direction D2 side, the first corner 291 has an R-chamfered shape and is located on the pressure-side assist cam surface 90A side, so that the clutch oil can be guided by the first corner 291 and supplied to the pressure-side assist cam surface 90A. In addition, because the second corner 292 has a pin-angle shape, the clutch oil can be splashed toward the pressure-side assist cam surface 90A located on the opposite side of the pressure-side cam hole 273H from the second corner 292.

[0109] In the clutch device 210 of this embodiment, the length of the pressure-side cam hole 273H in the circumferential direction S is longer than the length of the spring accommodating portion 54 in the circumferential direction S. According to the above aspect, the length of the pressure-side cam hole 273H in the circumferential direction S is ensured to be longer than the length of the spring accommodating portion 54 in the circumferential direction S, so that clutch oil can be supplied to the pressure-side assist cam surface 90A through the pressure-side cam hole 273H.

[0110] 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.

[0111] In the above-described embodiments, the clutch centers 40, 240 and the pressure plates 70, 270 are each configured to hold the output side rotating plates 22, but this is not limiting. For example, the clutch centers 40, 240 may hold all of the output side rotating plates 22, and the pressure plates 70, 270 may not hold any of the output side rotating plates 22. Furthermore, the pressure plates 70, 270 may hold all of the output side rotating plates 22, and the clutch centers 40, 240 may not hold any of the output side rotating plates 22.

[0112] In the above-described embodiments, the pressure plates 70 and 270 hold one output side rotary plate 22, but may hold a plurality of output side rotary plates 22.

[0113] In the above-described embodiments, the output shaft holding portion 50, 250 and the center-side fitting teeth 47, 247 are formed integrally, but this is not limiting. For example, the clutch center 40, 240 may have an inner diameter side portion having the output shaft holding portion 50, 250, and an outer diameter side portion formed separately from the inner diameter side portion and having the center-side fitting teeth 47, 247. In this case, the center-side cam hole 43H, 243H is preferably provided in the inner diameter side portion, but may also be provided in the outer diameter side portion. [Explanation of symbols]

[0114] 10. Clutch device 15 Output shaft 25 clutch spring 40 Clutch center 43H Center side cam hole 54 Spring housing 60 Center side cam part 60A Center side assist cam surface 60S Center side slipper cam surface 61 1st corner 62 Second corner 68 Center flange 70 Pressure Plate 90A Pressure side assist cam surface 90S Pressure side slipper cam surface 98 Pressure side flange 99 recess 100 Stopper plate 210 Clutch device 240 Clutch Center 270 Pressure Plate 273H Pressure side cam hole 290 Pressure side cam part 291 1st corner 292 Second corner 70 Pressure Plate 299 recess 300 Stopper plate

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 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 able to approach and move away from the clutch center, that holds at least some of the plurality of output side rotating plates that are arranged alternately with the input side rotating plate, and that can press the input side rotating plate and the output side rotating plate; a stopper plate that is fixed to the clutch center and 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 more than a predetermined distance, when the direction in which the pressure plate approaches and moves away from the clutch center is defined as a movement direction, the direction in which the pressure plate approaches the clutch center is defined as a first direction, and the direction in which the pressure plate moves away from the clutch center is defined as a second direction, The pressure plate is a plurality of pressure-side cam portions each having a pressure-side assist cam surface that generates a force from the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotary plate and the output-side rotary plate when the pressure plate rotates relative to the clutch center, and a pressure-side slipper cam surface that separates the pressure plate from the clutch center in order to decrease the pressing force between the input-side rotary plate and the output-side rotary plate; a plurality of pressure-side cam holes formed between adjacent pressure-side cam portions, When viewed in the axial direction of the output shaft, at least a portion of the pressure-side assist cam surface and the pressure-side cam hole overlap with each other, The pressure side cam portion is a first corner portion that defines an open end portion of the pressure-side cam hole on the second direction side and is located on one side of the pressure-side cam hole in the circumferential direction of the pressure plate; a second corner portion that defines an opening end of the pressure-side cam hole on the second direction side and is located on the other side of the pressure-side cam hole in the circumferential direction, The clutch device, wherein the first corner portion has a rounded chamfered shape and the second corner portion has a pin-angled shape.

2. a first circumferential direction is a direction from one side to the other side in the circumferential direction, and a second circumferential direction is a direction from the other side to the one side, the pressure plate is configured to rotate in the first circumferential direction, the first corner portion is located on the second circumferential direction side of the pressure-side cam hole, The clutch device according to claim 1 , wherein the second corner portion is located on the first circumferential side of the pressure-side cam hole.

3. The pressure plate is an accommodating portion that is formed in the pressure-side cam portion so as to be located on the second circumferential direction side of the first corner portion, that is recessed from the second direction toward the first direction, and that accommodates a clutch spring that urges the pressure plate in the first direction; a pressure-side flange located radially outward of the pressure-side cam portion and capable of pressing the input-side rotary plate and the output-side rotary plate; 3. The clutch device according to claim 2, further comprising: a recess formed in the pressure-side flange so as to be positioned radially outward of the housing portion and recessed from the second direction toward the first direction.

4. the first corner portion is located on the pressure-side assist cam surface side, 2. The clutch device according to claim 1, wherein the second corner portion is located on the pressure-side slipper cam surface side.

5. The pressure plate is a housing portion that is formed between adjacent pressure-side cam holes, that is recessed from the second direction toward the first direction, and that houses a clutch spring that urges the pressure plate in the first direction, 2. The clutch device according to claim 1, wherein the pressure-side cam hole has a length in the circumferential direction that is longer than the length of the accommodation portion in the circumferential direction.

6. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center 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 able to approach and move away from the clutch center, that holds at least some of the plurality of output side rotating plates that are arranged alternately with the input side rotating plate, and that can press the input side rotating plate and the output side rotating plate; a stopper plate that is fixed to the pressure plate and is capable of coming into contact with the clutch center, and that prevents the pressure plate from moving away from the clutch center in the second direction by more than a predetermined distance, when the direction in which the pressure plate approaches and moves away from the clutch center is defined as a movement direction, the direction in which the pressure plate approaches the clutch center is defined as a first direction, and the direction in which the pressure plate moves away from the clutch center is defined as a second direction, The clutch center is a plurality of center-side cam portions each having a center-side assist cam surface that generates a force from the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotary plate and the output-side rotary plate when the pressure plate rotates relative to the pressure plate, and 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 rotary plate and the output-side rotary plate; a plurality of center-side cam holes formed between adjacent center-side cam portions, When viewed in the axial direction of the output shaft, at least a portion of the center-side assist cam surface and the center-side cam hole overlap with each other, The center side cam portion is a first corner portion that defines an open end portion of the center-side cam hole on the first direction side and is located on one side of the center-side cam hole in the circumferential direction of the clutch center; a second corner portion that defines an open end portion of the center-side cam hole on the first direction side and is located on the other side of the center-side cam hole in the circumferential direction, The clutch device, wherein the first corner portion has a rounded chamfered shape and the second corner portion has a pin-angled shape.

7. When a direction from one side to the other side in the circumferential direction is defined as a first circumferential direction and a direction from the other side to the one side is defined as a second circumferential direction, the clutch center is configured to rotate in the first circumferential direction, the first corner portion is located on the first circumferential side of the center-side cam hole, The clutch device according to claim 6, wherein the second corner portion is located on the second circumferential side of the center-side cam hole.

8. The clutch center is an accommodating portion that is formed in the center-side cam portion so as to be located on the first circumferential direction side of the first corner portion, that is recessed from the first direction toward the second direction, and that accommodates a clutch spring that urges the pressure plate in the first direction; a center-side flange located radially outward of the center-side cam portion and capable of pressing the input-side rotary plate and the output-side rotary plate; 8. The clutch device according to claim 7, further comprising: a recess formed in the center-side flange so as to be positioned radially outward of the accommodating portion and recessed from the first direction toward the second direction.

9. the first corner portion is located on the center-side assist cam surface side, 7. The clutch device according to claim 6, wherein the second corner portion is located on the side of the center-side slipper cam surface.

10. The clutch center is an accommodating portion formed between adjacent center-side cam holes, recessed from the first direction toward the second direction, and configured to accommodate a clutch spring that urges the pressure plate in the first direction; 7. The clutch device according to claim 6, wherein the length of the center cam hole in the circumferential direction is longer than the length of the housing portion in the circumferential direction.

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