Clutch device

Abstract

To realize weight reduction of cam portions including an assist cam surface and a slipper cam surface.SOLUTION: A clutch device 10 includes a pressure plate 70, which is movable toward or away from and rotatable relative to a clutch center 40 and can press input-side rotating plates 20 and output-side rotating plates 22. The clutch center 40 includes multiple center-side cam portions 60 each having a center-side assist cam surface 60A. A center-side cam portion 60 includes at least one of: a first center-side recess 62 recessed in a first direction D1 from a surface 60D2 of the center-side cam portion 60 at the side of a second direction D2; and a second center-side recess 64 recessed in the second direction D2 from a surface 60D1 of the center-side cam portion 60 at the side of the first direction D1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, vehicles such as motorcycles have been equipped with clutch devices. The clutch device is disposed between an engine and a drive wheel to transmit or interrupt the rotational driving force of the engine to the drive wheel. The clutch device typically includes a plurality of input rotating plates that rotate due to the rotational driving force of the engine, and a plurality of output rotating plates connected to an output shaft that transmits the rotational driving force to the drive wheel. The input rotating plates and output rotating plates are arranged alternately in the stacking direction, and the transmission or interruption of the rotational driving force is performed by pressing the input rotating plates and the output rotating plates together and separating them.

[0003] For example, Patent Document 1 discloses a clutch device that includes a clutch center (clutch member) that holds an output-side rotating plate (driven-side clutch plate) and a pressure plate (pressure member) that is provided so as to be able to approach and move away from the clutch center. The pressure plate is configured so as to be able to press against the input-side rotating plate and the output-side rotating plate. In this way, the clutch device uses an assembled clutch center and pressure plate.

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

[0005] [Patent Document 1] Patent No. 5847551 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the cam portion of the clutch center and pressure plate, which includes the assist cam surface and slipper cam surface, has a relatively large thickness. Therefore, the larger the cam portion, the greater the weight, which increases the weight of the entire clutch device. Since the clutch device is mounted on a vehicle such as a motorcycle, a relatively lightweight one is preferable.

[0007] The present invention has been made in consideration of these points, and its purpose is to provide a clutch device in which the weight of a cam portion having an assist cam surface and a slipper cam surface is reduced on at least one of the clutch center and the pressure plate. [Means for solving the problem]

[0008] A clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational drive force of an input shaft to an output shaft, and includes: a clutch center housed in a clutch housing that holds a plurality of input rotating plates that are rotationally driven by the rotational drive of the input shaft, that holds a plurality of output rotating plates arranged alternately with the input rotating plates, and that rotates together with the output shaft; and a pressure plate that is capable of approaching or moving away from the clutch center and rotatable relative to the clutch center and can press the input rotating plates and the output rotating plates. The clutch center includes an output shaft holding portion to which the output shaft is connected, and a plurality of center-side cam portions that are located radially outward of the output shaft holding portion and have center-side assist cam surfaces that, when rotating relative to the pressure plate, generate a force that moves the pressure plate toward the clutch center to increase the pressing force between the input rotating plate and the output rotating plate. When 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 center-side cam portion has at least one of a first center-side recess recessed in the first direction from the surface of the center-side cam portion on the second direction side and a second center-side recess recessed in the second direction from the surface of the center-side cam portion on the first direction side.

[0009] In the clutch device according to the present invention, the center-side cam portion has at least one of a first center-side recess recessed in a first direction from the surface of the center-side cam portion facing the second direction and a second center-side recess recessed in a second direction from the surface of the center-side cam portion facing the first direction. Because the center-side cam portion has at least one of the first center-side recess and the second center-side recess, the center-side cam portion is lighter than if it did not have these recesses. Since the clutch device includes a lighter clutch center, the weight of the entire clutch device is reduced.

[0010] Another clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational drive force of an input shaft to an output shaft, the clutch device including: a clutch center accommodated in a clutch housing that holds a plurality of input rotating plates that are rotationally driven by the rotational drive of the input shaft, that holds a plurality of output rotating plates arranged alternately with the input rotating plates, and that rotates together with the output shaft; and a pressure plate that is capable of approaching or moving away from the clutch center and rotatable relative to the clutch center, and that can press the input rotating plates and the output rotating plates. The pressure plate is located radially outward of the output shaft, and has a plurality of pressure-side cam portions that have pressure-side assist cam surfaces that, when rotating relative to the clutch center, generate a force that moves the pressure plate toward the clutch center to increase the pressing force between the input rotating plate and the output rotating plate. When 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 side cam portion has at least one of a first pressure side recess that is recessed in the second direction from the surface of the pressure side cam portion on the first direction side and a second pressure side recess that is recessed in the first direction from the surface of the pressure side cam portion on the second direction side, and when viewed from the axial direction of the output shaft, at least a portion of the first pressure side recess overlaps with the pressure side assist cam surface.

[0011] According to another clutch device of the present invention, the pressure-side cam portion has at least one of a first pressure-side recess recessed in a second direction from a surface of the pressure-side cam portion facing a first direction and a second pressure-side recess recessed in a first direction from a surface of the pressure-side cam portion facing a second direction. Because the pressure-side cam portion has at least one of the first pressure-side recess and the second pressure-side recess, the pressure-side cam portion is lighter than a pressure-side cam portion that does not have these recesses. The clutch device includes a lighter pressure plate, thereby achieving a reduction in the overall weight of the clutch device. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a clutch device in which a weight reduction is realized in a cam portion having an assist cam surface and a slipper cam surface on at least one of the clutch center and the pressure plate. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view of a clutch device according to one embodiment. [Figure 2] FIG. 2 is a perspective view of a clutch center according to one embodiment. [Figure 3] FIG. 3 is a plan view of the clutch center according to one embodiment. [Figure 4] FIG. 4 is a perspective view of a clutch center according to one embodiment. [Figure 5] FIG. 5 is a plan view of the clutch center according to one embodiment. [Figure 6] FIG. 6 is a perspective view of a pressure plate according to one embodiment. [Figure 7] FIG. 7 is a plan view of a pressure plate according to one embodiment. [Figure 8] FIG. 8 is a perspective view of a pressure plate according to one embodiment. [Figure 9] FIG. 9 is a plan view of a pressure plate according to one embodiment. [Figure 10] FIG. 10 is a side view of a pressure plate according to one embodiment. [Figure 11] FIG. 11 is a plan view showing a state in which the clutch center and pressure plate according to one embodiment are combined. [Figure 12] FIG. 12 is a plan view showing a state in which the clutch center and pressure plate according to one embodiment are combined. [Figure 13A] FIG. 13A is a schematic diagram illustrating the action of the center-side assist cam surface and the pressure-side assist cam surface. [Figure 13B]FIG. 13B is a schematic diagram illustrating the action of the center-side slipper cam surface and the pressure-side slipper cam surface. [Figure 14] FIG. 14 is a cross-sectional view of a center-side cam portion according to one embodiment. [Figure 15] FIG. 15 is a cross-sectional view of a pressure-side cam portion according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] 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.

[0015] FIG. 1 is a cross-sectional view of a clutch device 10 according to this embodiment. The clutch device 10 is provided on a vehicle such as a motorcycle. The clutch device 10 is a device that transmits or cuts off the rotational driving force of an input shaft (crankshaft) of an engine of the motorcycle to an output shaft 15, for example. The clutch device 10 is a device that transmits or cuts off the rotational driving force of the input shaft to a driving wheel (rear wheel) via the output shaft 15. The clutch device 10 is disposed between the engine and the transmission.

[0016] In the following description, the direction in which the pressure plate 70 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 a first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is referred to as a second direction D2. The circumferential direction of the clutch center 40 and the pressure plate 70 is referred to as a circumferential direction S, and the direction from one pressure-side cam portion 90 to the other pressure-side cam portion 90 with respect to the circumferential direction S (the direction from one center-side cam portion 60 to the other center-side cam portion 60) is referred to as a first circumferential direction S1 (see FIG. 7), and the direction from the other pressure-side cam portion 90 to one pressure-side cam portion 90 (the direction from the other center-side cam portion 60 to one center-side cam portion 60) is referred to as a second circumferential direction S2 (see FIG. 7). In this embodiment, the axial direction of the output shaft 15, the axial direction of the clutch housing 30, the axial direction of the clutch center 40, and the axial direction of the pressure plate 70 are the same as direction D. Furthermore, the pressure plate 70 and the clutch center 40 rotate in a first circumferential direction S1 (i.e., the direction from the center-side assist cam surface 60A of one center-side cam portion 60 toward the center-side slipper cam surface 60S). However, the above directions are merely defined for the convenience of explanation, and do not limit in any way the installation mode of the clutch device 10 or the present invention.

[0017] 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.

[0018] 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 needle bearing 15A. The output shaft 15 fixedly supports a clutch center 40 via a nut 15B. That is, the output shaft 15 rotates integrally with the clutch center 40. The other end of the output shaft 15 is connected to, for example, a transmission (not shown) of a motorcycle.

[0019] As shown in FIG. 1 , the output shaft 15 includes a hollow portion 15H, which houses a push rod 16A and a push member 16B located adjacent to the push rod 16A. The hollow portion 15H functions as a passageway 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 disposed 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 70. 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.

[0020] 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 from an edge of the bottom wall 31 in the second direction D2. The clutch housing 30 holds a plurality of input side rotating plates 20.

[0021] 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.

[0022] 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 in the clutch housing 30 by spline fitting. The input side rotating plate 20 is provided so as to be displaceable along the axial direction of the clutch housing 30. The input side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0023] 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 a flat plate formed in an annular shape. The input side rotating plate 20 is formed by punching out an annular shape from a thin plate made of SPCC (cold rolled steel plate). 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 μm to several tens of μm deep are formed between the friction materials to hold clutch oil.

[0024] As shown in FIG. 1 , the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is arranged concentrically with the clutch housing 30. The clutch center 40 has a cylindrical main body 42 and a flange 68 extending radially outward from the outer periphery of the main body 42. The clutch center 40 holds an input side rotating plate 20 and a plurality of output side rotating plates 22 arranged alternately in direction D. The clutch center 40 is driven to rotate together with the output shaft 15.

[0025] As shown in Figure 2, the main body 42 includes an annular base wall 43, an outer peripheral wall 45 located radially outward of the base wall 43 and extending toward the second direction D2, an output shaft holding portion 50 provided in the center of the base wall 43, a plurality of center side cam portions 60 connected to the base wall 43 and the outer peripheral wall 45, and a center side fitting portion 58.

[0026] The output shaft holding portion 50 is formed in a cylindrical shape. An insertion hole 51 is formed in the output shaft holding portion 50, into which the output shaft 15 is inserted and spline-fitted. The insertion hole 51 is formed to penetrate the base wall 43. An inner circumferential surface 50A of the output shaft holding portion 50, which forms the insertion hole 51, is formed with a plurality of spline grooves along the axial direction. The output shaft 15 is connected to the output shaft holding portion 50.

[0027] As shown in FIG. 2 , the outer peripheral wall 45 of the clutch center 40 is disposed radially outward of the output shaft holding portion 50. The outer peripheral wall 45 is positioned radially outward of the center-side cam portion 60. A spline fitting portion 46 is provided on an outer peripheral surface 45A of the outer peripheral wall 45. The spline fitting portion 46 has a plurality of center-side fitting teeth 47 extending in the axial direction of the clutch center 40 along the outer peripheral surface 45A of the outer peripheral wall 45, a plurality of spline grooves 48 formed between adjacent center-side fitting teeth 47 and extending in the axial direction of the clutch center 40, and an oil discharge hole 49. The center-side fitting teeth 47 hold the 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 to have the same shape. The center-side fitting teeth 47 protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45. The oil discharge holes 49 are formed by penetrating the outer peripheral wall 45 in the radial direction. The oil discharge holes 49 are formed between adjacent center-side fitting teeth 47. That is, the oil discharge holes 49 are formed in the spline grooves 48. The oil discharge holes 49 are formed on the sides of the center-side cam portion 60. The oil discharge holes 49 are formed on the sides of the center-side slipper cam surface 60S of the center-side cam portion 60. The oil discharge holes 49 are formed on the second circumferential direction S2 side of the center-side slipper cam surface 60S. The oil discharge holes 49 are formed on the first circumferential direction S1 side of a boss portion 54, which will be described later. In this embodiment, two oil discharge holes 49 are formed at each of three locations in the circumferential direction S of the outer peripheral wall 45. The oil discharge holes 49 are arranged at equal intervals in the circumferential direction S. The oil discharge hole 49 connects the inside and outside of the clutch center 40. The oil discharge hole 49 is a hole that discharges clutch oil that has flowed into the clutch center 40 from the output shaft 15 to the outside of the clutch center 40.

[0028] The output side rotating plate 22 is held by the spline fitting portion 46 of the clutch center 40 and the pressure plate 70. A portion of the output side rotating plate 22 is held by the center side fitting teeth 47 and the spline grooves 48 of the clutch center 40 through spline fitting. Another portion of the output side rotating plate 22 is held by the pressure side fitting teeth 77 (see FIG. 6 ) of the pressure plate 70, which will be described later. The output side rotating plate 22 is provided so as to be displaceable along the axial direction of the clutch center 40. The output side rotating plate 22 is provided so as to be rotatable integrally with the clutch center 40.

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

[0030] The center-side cam portion 60 is formed in a platform shape having 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, causing the clutch to transition to a half-clutch state. The center-side cam portion 60 is formed to protrude from the base wall 43 in the second direction D2. As shown in FIG. 3 , 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. 3 , the center-side cam portion 60 is located radially outward of the output shaft holding portion 50. The center-side cam portion 60 has a center-side assist cam surface 60A and a center-side slipper cam surface 60S. The center-side assist cam surface 60A is configured to generate a force in a direction that moves the pressure plate 70 closer to the clutch center 40 when it rotates relative to the pressure plate 70, 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 move closer to 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 when rotating relative to the pressure plate 70 in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22. 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 FIG. 2, the center-side cam portion 60 has a first center-side recess 62 recessed in the first direction D1 from a surface 60D2 on the second direction D2 side of the center-side cam portion 60. The first center-side recess 62 is located closer to the second circumferential direction S2 than the center-side slipper cam surface 60S. As shown in FIG. 5, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the first center-side recess 62 overlaps with the center-side assist cam surface 60A. As shown in FIG. 14, the first center-side recess 62 has a first center-side inclined surface 63 parallel to the center-side assist cam surface 60A. The first center-side inclined surface 63 is inclined toward the second direction D2 as it approaches the second circumferential direction S2.

[0033] As shown in FIG. 4, the center-side cam portion 60 has a second center-side recess 64 recessed in the second direction D2 from a surface 60D1 on the first direction D1 side of the center-side cam portion 60. The second center-side recess 64 is located closer to the first circumferential direction S1 than the center-side assist cam surface 60A. As shown in FIG. 3, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the second center-side recess 64 overlaps with the center-side slipper cam surface 60S. As shown in FIG. 14, the second center-side recess 64 has a second center-side inclined surface 65 parallel to the center-side slipper cam surface 60S. The second center-side inclined surface 65 is inclined toward the first direction D1 as it approaches the first circumferential direction S1.

[0034] As shown in FIG. 14, the end 62A of the first center-side recess 62 in the first direction D1 is located closer to the first direction D1 than the end 64A of the second center-side recess 64 in the second direction D2. The end 62A of the first center-side recess 62 in the first direction D1 may be located closer to the second direction D2 than the end 64A of the second center-side recess 64 in the second direction D2. The length L1 of the first center-side recess 62 in the direction D is shorter than the length L2 of the second center-side recess 64 in the direction D. The length LS1 of the first center-side recess 62 in the circumferential direction S is shorter than the length LS2 of the second center-side recess 64 in the circumferential direction S. As shown in FIG. 3, the first center-side recess 62 and the second center-side recess 64 do not overlap when viewed from the axial direction of the output shaft 15 (i.e., in the direction D).

[0035] As shown in FIG. 3 , the clutch center 40 has an oil passage 53 formed through the outer peripheral wall 45. The oil passage 53 is formed in a spline groove 48 so as to penetrate the outer peripheral wall 45. The oil passage 53 is formed between adjacent center-side fitting teeth 47. One end of the oil passage 53 opens radially inward and communicates with the second center-side recess 64. The other end of the oil passage 53 opens radially outward and communicates with the outside of the outer peripheral wall 45. The oil passage 53 is configured to guide clutch oil that flows from the output shaft 15 and into the second center-side recess 64 from the first direction D1 side of the clutch center 40 to the outside of the clutch center 40 (to the radial outside of the clutch center 40) via the spline groove 48. As a result, clutch oil is supplied via the oil passage 53 to the output-side rotating plate 22 and the input-side rotating plate 20 held by the center-side fitting teeth 47.

[0036] As shown in FIG. 2, the clutch center 40 has a plurality of boss portions 54 (three in this embodiment). The boss portions 54 are members that support the pressure plate 70. The plurality of boss portions 54 are arranged at equal intervals in the circumferential direction S. The boss portions 54 are formed in a cylindrical shape. The boss portions 54 are located radially outward from the output shaft holding portion 50. The boss portions 54 extend toward the pressure plate 70 (i.e., toward the second direction D2). The boss portions 54 are provided on the base wall 43. A threaded hole 54H is formed in the boss portion 54, into which the bolt 28 (see FIG. 1) is inserted. The threaded hole 54H extends in the axial direction of the clutch center 40.

[0037] As shown in FIG. 2, the center-side fitting portion 58 is located radially outward from the output shaft holding portion 50. The center-side fitting portion 58 is located radially outward from the center-side cam portion 60. The center-side fitting portion 58 is located closer to the second direction D2 than the center-side cam portion 60. The center-side fitting portion 58 is formed on the inner peripheral surface of the outer peripheral wall 45. The center-side fitting portion 58 is configured to slidably fit onto a pressure-side fitting portion 88 (see FIG. 6), which will be described later. The inner diameter of the center-side fitting portion 58 is formed with a fitting tolerance that allows the clutch oil flowing out from the tip end 15T of the output shaft 15 to pass through relative to the pressure-side fitting portion 88. That is, a gap is formed between the center-side fitting portion 58 and the pressure-side fitting portion 88, which will be described later. In this embodiment, for example, the center-side fitting portion 58 is formed with an inner diameter that is 0.1 mm larger than the outer diameter of the pressure-side fitting portion 88. The dimensional tolerance between the inner diameter of the center-side fitting portion 58 and the outer diameter of the pressure-side fitting portion 88 is set appropriately depending on the amount of clutch oil that is desired to be circulated, but is, for example, 0.1 mm or more and 0.5 mm or less.

[0038] 2 and 3, the clutch center 40 has a center-side cam hole 43H that penetrates a portion of the base wall 43. The center-side cam hole 43H extends from the side of the output shaft holding portion 50 to the outer peripheral wall 45. The center-side cam hole 43H is formed to penetrate between adjacent center-side cam portions 60. The center-side cam hole 43H is formed between the center-side assist cam surface 60A of the center-side cam portion 60 and the boss portion 54. When viewed from the axial direction of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0039] As shown in FIG. 1 , the pressure plate 70 is provided so as to be able to move toward or away from the clutch center 40 and to rotate relative to it. The pressure plate 70 is configured to be able to press the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 70 is arranged concentrically with the clutch center 40 and the clutch housing 30. The pressure plate 70 has a main body 72 and a flange 98 that is connected to the outer 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 flange 98. The flange 98 is located radially outward beyond a cylindrical portion 80 (see FIG. 6 ), which will be described later. The pressure plate 70 holds a plurality of output side rotating plates 22 that are arranged alternately with the input side rotating plates 20. The flange 98 is configured to be able to press the input side rotating plate 20 and the output side rotating plate 22.

[0040] As shown in FIG. 6, the main body 72 includes a cylindrical portion 80, a plurality of pressure-side cam portions 90, a pressure-side fitting portion 88, and a spring accommodating portion 84 (see also FIG. 8).

[0041] The cylindrical portion 80 is formed in a cylindrical shape. The cylindrical portion 80 is formed integrally with the pressure-side cam portion 90. The cylindrical portion 80 accommodates the tip portion 15T (see FIG. 1) of the output shaft 15. The cylindrical portion 80 accommodates the release bearing 18 (see FIG. 1). The cylindrical portion 80 is a portion that receives a pressing force from the push member 16B. The cylindrical portion 80 is a portion that receives clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0042] 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 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.

[0043] As shown in FIG. 7, the pressure-side cam portion 90 is located radially outward of the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also FIG. 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 that moves the pressure plate 70 closer to the clutch center 40 when rotating relative to the clutch center 40, in order to increase the pressing force (pressing force) between the input-side rotating plate 20 and the output-side rotating plate 22. The pressure-side slipper cam surface 90S is configured to be able to come into contact with the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to move the pressure plate 70 away from the clutch center 40 in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22 when rotating relative to the clutch center 40. In the pressure-side cam portions 90 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 90M are arranged opposite each other in the circumferential direction S.

[0044] As shown in FIG. 6, the pressure-side cam portion 90 has a first pressure-side recess 92 recessed in the second direction D2 from a surface 90D1 on the first direction D1 side of the pressure-side cam portion 90. The first pressure-side recess 92 is located closer to the first circumferential direction S1 than the pressure-side slipper cam surface 90S. As shown in FIG. 9, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the first pressure-side recess 92 overlaps with the pressure-side assist cam surface 90A. As shown in FIG. 15, the first pressure-side recess 92 has a first pressure-side inclined surface 93 parallel to the pressure-side assist cam surface 90A. The first pressure-side inclined surface 93 is inclined toward the first direction D1 as it approaches the first circumferential direction S1.

[0045] As shown in FIG. 8, the pressure-side cam portion 90 has a second pressure-side recess 94 recessed in the first direction D1 from a surface 90D2 on the second direction D2 side of the pressure-side cam portion 90. The second pressure-side recess 94 is located closer to the second circumferential direction S2 than the pressure-side assist cam surface 90A. As shown in FIG. 7, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the second pressure-side recess 94 overlaps with the pressure-side slipper cam surface 90S. As shown in FIG. 15, the second pressure-side recess 94 has a second pressure-side inclined surface 95 parallel to the pressure-side slipper cam surface 90S. The second pressure-side inclined surface 95 is inclined toward the second direction D2 as it approaches the second circumferential direction S2. As shown in FIG. 10, an end 94A of the second pressure-side recess 94 in the first direction D1 is located closer to the first direction D1 than an end 88A of the pressure-side fitting portion 88 in the first direction D1.

[0046] 15, an end 92A of the first pressure side recess 92 in the second direction D2 is located closer to the first direction D1 than an end 94A of the second pressure side recess 94 in the first direction D1. Note that the end 92A of the first pressure side recess 92 in the second direction D2 may be located closer to the second direction D2 than the end 94A of the second pressure side recess 94 in the first direction D1. As shown in FIG. 3, the first pressure side recess 92 and the second pressure side recess 94 do not overlap when viewed from the axial direction of the output shaft 15 (i.e., direction D).

[0047] As shown in FIG. 11, when viewed from the axial direction of the output shaft 15 (i.e., direction D; here, first direction D1), the second pressure-side recess 94 of the pressure plate 70 and the first center-side recess 62 of the clutch center 40 do not overlap. When viewed from the axial direction of the output shaft 15 (i.e., direction D; here, first direction D1), at least a portion of the first center-side recess 62 of the clutch center 40 overlaps with the pressure-side cam hole 73H of the pressure plate 70. That is, the first center-side recess 62 is exposed to the outside through the pressure-side cam hole 73H. Also, as shown in FIG. 12, when viewed from the axial direction of the output shaft 15 (i.e., direction D; here, second direction D2), the first pressure-side recess 92 of the pressure plate 70 and the second center-side recess 64 of the clutch center 40 do not overlap. When viewed from the axial direction of the output shaft 15 (i.e., direction D; here, second direction D2), at least a portion of the first pressure-side recess 92 of the pressure plate 70 overlaps with the center-side cam hole 43H of the clutch center 40. In other words, the first pressure-side recess 92 is exposed to the outside through the center-side cam hole 43H.

[0048] Here, the function 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. 13A. 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. Note that the first center-side recess 62 and other components are not shown in FIG. 13A.

[0049] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational 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. 13B. 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 malfunctions in the engine and transmission due to back torque. Note that the first center-side recess 62 and other components are not shown in FIG. 13B.

[0050] 6, the pressure-side fitting portion 88 is located radially outward from the pressure-side cam portion 90. The pressure-side fitting portion 88 is located closer to the second direction D2 than the pressure-side cam portion 90. The pressure-side fitting portion 88 is configured to be slidably fitted into the center-side fitting portion 58 (see FIG. 2).

[0051] As shown in FIGS. 6 and 7, the pressure plate 70 has a pressure-side cam hole 73H that penetrates a portion of the main body 72 and the flange 98. The pressure-side cam hole 73H is located radially outward of the cylindrical portion 80. The pressure-side cam hole 73H extends from a side of the cylindrical portion 80 to a position radially outward of the pressure-side fitting portion 88. 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 between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 90. As shown in FIGS. 7 and 9, when viewed in the axial direction of the pressure plate 70, the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 73H overlap.

[0052] As shown in FIG. 6, the pressure plate 70 has a plurality of pressure side fitting teeth 77 arranged on a flange 98. The pressure side fitting teeth 77 hold the output side rotating plate 22. The pressure side fitting teeth 77 protrude from the flange 98 in a first direction D1. The pressure side fitting teeth 77 are located radially outward from the cylindrical portion 80. They are located radially outward from the pressure side cam portion 90. The pressure side fitting teeth 77 are located radially outward from the pressure side cam portion 90. The pressure side fitting teeth 77 are located radially outward from the pressure side fitting portion 88. The plurality of pressure side fitting teeth 77 are aligned in the circumferential direction S. The plurality of pressure side fitting teeth 77 are arranged at equal intervals in the circumferential direction S. In this embodiment, some of the pressure-side fitting teeth 77 are removed, so the spacing between those parts is wider, but the other adjacent pressure-side fitting teeth 77 are arranged at equal intervals.

[0053] As shown in Figures 8 and 9, the spring accommodating portion 84 is formed in the pressure-side cam portion 90. The spring accommodating portion 84 is located between the first pressure-side recess 92 and the second pressure-side recess 94. The spring accommodating portion 84 is formed so as to be recessed from the second direction D2 to the first direction D1. The spring accommodating portion 84 is formed in an elliptical shape. The spring accommodating portion 84 accommodates the pressure spring 25 (see Figure 1). An insertion hole 84H, into which the boss portion 54 (see Figure 2) is inserted, is formed through the spring accommodating portion 84. That is, the insertion hole 84H is formed through the pressure-side cam portion 90. The insertion hole 84H is formed in an elliptical shape.

[0054] 1, the pressure spring 25 is housed in the spring housing portion 84. The pressure spring 25 is held by the boss portion 54 inserted into the insertion hole 84H of the spring housing portion 84. The pressure spring 25 biases the pressure plate 70 toward the clutch center 40 (i.e., toward the first direction D1). The pressure spring 25 is, for example, a coil spring formed by spirally winding spring steel.

[0055] 11 and 12 are plan views showing the state in which the clutch center 40 and the pressure plate 70 are assembled. In the state shown in Figures 11 and 12, the pressure-side assist cam surface 90A and the center-side assist cam surface 60A do not contact each other, and the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S do not contact each other. At this time, the pressure plate 70 is closest to the clutch center 40.

[0056] As shown in FIG. 1 , the stopper plate 100 is provided so as to be able to come into contact with the pressure plate 70. The stopper plate 100 is a member that prevents the pressure plate 70 from moving away from the clutch center 40 by more than a predetermined distance in the second direction D2. The stopper plate 100 is fixed to the boss portion 54 of the clutch center 40 by the bolt 28. The pressure plate 70 is fixed by tightening the bolt 28 to the boss portion 54 via the stopper plate 100 with the boss portion 54 of the clutch center 40 and the pressure spring 25 disposed in the spring accommodating portion 84. The stopper plate 100 is formed in a substantially triangular shape in a plan view.

[0057] Here, when the pressure plate 70 contacts the stopper plate 100, the contact areas of the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S are 50% to 90% of the area of ​​the pressure-side slipper cam surface 90S and 50% to 90% of the area of ​​the center-side slipper cam surface 60S, respectively. Furthermore, when the pressure plate 70 contacts the stopper plate 100, the pressure spring 25 is spaced apart from the side wall of the spring accommodating portion 84. In other words, the pressure spring 25 is not sandwiched between the boss portion 54 and the spring accommodating portion 84, and application of excessive stress to the boss portion 54 is suppressed.

[0058] A predetermined amount of clutch oil is filled inside the clutch device 10. The clutch oil flows through the hollow portion 15H of the output shaft 15 into the clutch center 40 and the pressure plate 70, and is then supplied to the input side rotating plate 20 and the output side rotating plate 22 through the gap between the center side fitting portion 58 and the pressure side fitting portion 88 and the oil discharge hole 49. The clutch oil absorbs heat and prevents wear of the friction material. The clutch device 10 of this embodiment is a so-called wet-type multi-plate friction clutch device.

[0059] Next, we will explain the operation of the clutch device 10 of this embodiment. As described above, the clutch device 10 is disposed between the engine and the transmission of the motorcycle, and transmits or cuts off the rotational driving force of the engine to the transmission when the rider operates the clutch operating lever.

[0060] When the rider of the motorcycle does not operate the clutch operating lever, the clutch release mechanism (not shown) does not press the push rod 16A, and the pressure plate 70 presses the input side rotating plate 20 by the biasing force (elastic force) of the pressure spring 25. As a result, the clutch center 40 is in a clutch-on state where the input side rotating plate 20 and the output side rotating plate 22 are pressed against each other and frictionally connected, and is driven to rotate. In other words, the rotational driving force of the engine is transmitted to the clutch center 40, and the output shaft 15 is driven to rotate.

[0061] In the clutch-on state, the clutch oil that flows inside the hollow portion H of the output shaft 15 and flows out from the tip end 15T of the output shaft 15 drops or flies into the cylindrical portion 80 and adheres thereto (see arrow F in FIG. 1). The clutch oil that adheres to the inside of the cylindrical portion 80 is guided into the clutch center 40. As a result, the clutch oil flows out of the clutch center 40 through the oil discharge hole 49. The clutch oil also flows out of the clutch center 40 through the gap between the center-side fitting portion 58 and the pressure-side fitting portion 88. The clutch oil that has flowed out of the clutch center 40 is then supplied to the input-side rotating plate 20 and the output-side rotating plate 22.

[0062] On the other hand, when the rider of the motorcycle operates the clutch operating lever while the clutch is in the ON state, the clutch release mechanism (not shown) presses the push rod 16A, causing the pressure plate 70 to displace in a direction (second direction D2) away from the clutch center 40 against the biasing force of the pressure spring 25. As a result, the clutch center 40 enters a clutch-off state in which the frictional connection between the input-side rotating plate 20 and the output-side rotating plate 22 is released, and the rotational drive is attenuated or stopped. In other words, the rotational drive force of the engine is cut off from the clutch center 40.

[0063] In the clutch-off state, the clutch oil that flows inside the hollow portion H of the output shaft 15 and flows out from the tip end 15T of the output shaft 15 is guided into the clutch center 40, just as in the clutch-on state. At this time, the pressure plate 70 moves away from the clutch center 40, reducing the amount of engagement between the center-side fitting portion 58 and the pressure-side fitting portion 88. As a result, the clutch oil in the cylindrical portion 80 more actively flows out of the clutch center 40 and flows to various locations inside the clutch device 10. In particular, the clutch oil can be actively guided between the input-side rotating plate 20 and the output-side rotating plate 22, which are spaced apart from each other.

[0064] When the driver releases the clutch operating lever in the clutch-off state, the pressure applied to the pressure plate 70 by the clutch release mechanism (not shown) via the push member 16B is released, and the pressure plate 70 is displaced in a direction approaching the clutch center 40 (first direction D1) by the force of the pressure spring 25.

[0065] As described above, according to the clutch device 10 of this embodiment, the center-side cam portion 60 has at least one of the first center-side recess 62 recessed in the first direction D1 from the surface 60D2 on the second direction D2 side of the center-side cam portion 60 and the second center-side recess 64 recessed in the second direction D2 from the surface D1 on the first direction D1 side of the center-side cam portion 60. As such, because the center-side cam portion 60 has at least one of the first center-side recess 62 and the second center-side recess 64, the center-side cam portion 60 is lighter than if it did not have these recesses. The clutch device 10 is provided with a lighter clutch center 40, and therefore the weight of the entire clutch device 10 is reduced.

[0066] In the clutch device 10 of this embodiment, the center-side cam portion 60 has the first center-side recess 62 and the second center-side recess 64. According to the above aspect, the center-side cam portion 60 can be made even lighter.

[0067] In the clutch device 10 of this embodiment, the end 62A of the first center-side recess 62 in the first direction D1 is located closer to the first direction D1 than the end 64A of the second center-side recess 64 in the second direction D2. According to the above aspect, the center-side cam portion 60 can be further reduced in weight.

[0068] In the clutch device 10 of this embodiment, at least a portion of the first center-side recess 62 overlaps with the center-side assist cam surface 60A when viewed from the axial direction of the output shaft 15 (i.e., direction D). According to the above aspect, the thickness of the portion having the center-side assist cam surface 60A can be made relatively thin, which allows for accurate molding during manufacturing and improves the surface properties, such as the surface roughness, of the center-side assist cam surface 60A.

[0069] In the clutch device 10 of this embodiment, the first center-side recess 62 has a first center-side inclined surface 63 that is parallel to the center-side assist cam surface 60A. According to the above aspect, the thickness of the portion having the center-side assist cam surface 60A can be made approximately uniform, thereby improving the performance of the center-side assist cam surface 60A.

[0070] In the clutch device 10 of this embodiment, the clutch center 40 is configured to rotate in a first circumferential direction S1, which is a direction from the center-side assist cam surface 60A of one center-side cam portion 60 toward the center-side slipper cam surface 60S, and the first center-side inclined surface 63 is inclined so as to approach the second direction D2 as it approaches the second circumferential direction S2. According to the above aspect, even if clutch oil accumulates in the first center-side recess 62, the clutch oil accumulated in the first center-side recess 62 flows out along the first center-side inclined surface 63 in the second circumferential direction S2.

[0071] In the clutch device 10 of this embodiment, at least a portion of the second center-side recess 64 overlaps with the center-side slipper cam surface 60S when viewed from the axial direction of the output shaft 15 (i.e., direction D). According to the above aspect, the thickness of the portion having the center-side slipper cam surface 60S can be made relatively thin, which allows for accurate molding during manufacturing and improves the surface properties, such as the surface roughness, of the center-side slipper cam surface 60S.

[0072] In the clutch device 10 of this embodiment, the second center-side recess 64 has a second center-side inclined surface 65 that is parallel to the center-side slipper cam surface 60S. According to the above aspect, the thickness of the portion having the center-side slipper cam surface 60S can be made approximately uniform, thereby improving the performance of the center-side slipper cam surface 60S.

[0073] In the clutch device 10 of this embodiment, the clutch center 40 includes an outer peripheral wall 45 located radially outward of the center-side cam portion 60, and an oil passage 53 formed through the outer peripheral wall 45, with one end opening radially inward and communicating with the second center-side recess 64 and the other end opening radially outward and communicating with the outside of the outer peripheral wall 45. According to the above aspect, the clutch oil that flows out from the output shaft 15 and into the second center-side recess 64 from the first direction D1 side of the clutch center 40 can be supplied to the output-side rotating plate 22 and the input-side rotating plate 20 via the oil passage 53.

[0074] In the clutch device 10 of this embodiment, the oil passages 53 are formed in the spline grooves 48 so as to penetrate the outer peripheral wall 45. According to the above aspect, the clutch oil flows along the spline grooves, so that the clutch oil can be supplied to the output side rotating plate 22 and the input side rotating plate 20 in a balanced manner.

[0075] In the clutch device 10 of this embodiment, the first center-side recess 62 and the second center-side recess 64 do not overlap when viewed in the axial direction of the output shaft 15 (i.e., direction D). According to the above aspect, even if the depths of the first center-side recess 62 and the second center-side recess 64 in the axial direction of the output shaft 15 are increased, they do not interfere with each other. Therefore, by making the depths of the first center-side recess 62 and the second center-side recess 64 relatively large, the weight of the center-side cam portion 60 can be further reduced.

[0076] According to the clutch device 10 of this embodiment, the pressure-side cam portion 90 has at least one of a first pressure-side recess 92 recessed in the second direction D2 from a surface 90D1 on the first direction D1 side of the pressure-side cam portion 90 and a second pressure-side recess 94 recessed in the first direction D1 from a surface 90DS on the second direction D2 side of the pressure-side cam portion 90. As such, because the pressure-side cam portion 90 has at least one of the first pressure-side recess 92 and the second pressure-side recess 94, the pressure-side cam portion 90 is lighter than a pressure-side cam portion 90 that does not have these recesses. The clutch device 10 is provided with a lighter pressure plate 70, and therefore the weight of the entire clutch device 10 is reduced.

[0077] In the clutch device 10 of this embodiment, the pressure-side cam portion 90 has the first pressure-side recess 92 and the second pressure-side recess 94. According to the above aspect, the weight of the pressure-side cam portion 90 can be further reduced.

[0078] In the clutch device 10 of this embodiment, the pressure plate 70 includes a spring accommodating portion 84 that is formed in the pressure-side cam portion 90 so as to be recessed from the second direction D2 to the first direction D1 and that accommodates the pressure spring 25 that urges the pressure plate 70 in the first direction D1, and the spring accommodating portion 84 is located between the first pressure-side recess 92 and the second pressure-side recess 94. According to the above aspect, the weight of the pressure-side cam portion 90 can be further reduced.

[0079] In the clutch device 10 of this embodiment, the end 92A of the first pressure-side recess 92 in the second direction D2 may be located closer to the second direction D2 than the end 94A of the second pressure-side recess 94 in the first direction D1. According to the above aspect, the weight of the pressure-side cam portion 90 can be further reduced.

[0080] In the clutch device 10 of this embodiment, the clutch center 40 includes an output shaft holding portion 50 to which the output shaft 15 is connected and a center-side fitting portion 58 located radially outward from the output shaft holding portion 50, the pressure plate 70 includes a pressure-side fitting portion 88 located radially outward from the pressure-side cam portion 90 and slidably fitted into the center-side fitting portion 58, and an end portion 94A in the first direction D1 of the second pressure-side recess 94 is located on the first direction D1 side of an end portion 88A in the first direction D1 of the pressure-side fitting portion 88. According to the above aspect, the weight of the pressure-side cam portion 90 can be further reduced.

[0081] In the clutch device 10 of this embodiment, at least a portion of the first pressure-side recess 92 overlaps with the pressure-side assist cam surface 90A when viewed from the axial direction (i.e., direction D) of the output shaft 15. According to the above aspect, the thickness of the portion having the pressure-side assist cam surface 90A can be made relatively thin, which allows for accurate molding during manufacturing and improves the surface properties, such as the surface roughness, of the pressure-side assist cam surface 90A.

[0082] In the clutch device 10 of this embodiment, the first pressure-side recess 92 has a first pressure-side inclined surface 93 that is parallel to the pressure-side assist cam surface 90A. According to the above aspect, the thickness of the portion having the pressure-side assist cam surface 90A can be made substantially uniform, thereby improving the performance of the pressure-side assist cam surface 90A.

[0083] In the clutch device 10 of this embodiment, at least a portion of the second pressure-side recess 94 overlaps with the pressure-side slipper cam surface 90S when viewed from the axial direction of the output shaft 15 (i.e., direction D). According to the above aspect, the thickness of the portion having the pressure-side slipper cam surface 90S can be made relatively thin, which allows for accurate molding during manufacturing and improves the surface properties, such as the surface roughness, of the pressure-side slipper cam surface 90S.

[0084] In the clutch device 10 of this embodiment, the second pressure-side recess 94 has a second pressure-side inclined surface 95 that is parallel to the pressure-side slipper cam surface 90S. According to the above aspect, the thickness of the portion having the pressure-side slipper cam surface 90S can be made substantially uniform, thereby improving the performance of the pressure-side slipper cam surface 90S.

[0085] In the clutch device 10 of this embodiment, the first pressure side recess 92 and the second pressure side recess 94 do not overlap when viewed in the axial direction of the output shaft 15 (i.e., direction D). According to the above aspect, even if the depths of the first pressure side recess 92 and the second pressure side recess 94 in the axial direction of the output shaft 15 are increased, they do not interfere with each other. Therefore, by making the depths of the first pressure side recess 92 and the second pressure side recess 94 relatively large, the weight of the pressure side cam portion 90 can be further reduced.

[0086] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 (i.e., direction D), the second pressure-side recess 94 of the pressure plate 70 and the first center-side recess 62 of the clutch center 40 do not overlap. According to the above aspect, clutch oil scattering toward the pressure plate 70 from the second direction D2 is more likely to flow into the second pressure-side recess 94 and the first center-side recess 62. The clutch oil that has flowed into the second pressure-side recess 94 and the first center-side recess 62 flows out of the second pressure-side recess 94 and the first center-side recess 62 during engine rotation fluctuations, for example, and is supplied to the pressure-side assist cam surface 90A of the pressure-side cam portion 90 and the center-side assist cam surface 60A of the center-side cam portion 60, etc., thereby smoothly lubricating the pressure-side assist cam surface 90A, the center-side assist cam surface 60A, etc.

[0087] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the first center-side recess 62 overlaps with the pressure-side cam hole 73H. According to the above aspect, clutch oil scattering toward the pressure plate 70 from the second direction D2 is more likely to flow into the first center-side recess 62 through the pressure-side cam hole 73H. The clutch oil that has flowed into the first center-side recess 62 flows out of the first center-side recess 62 during engine rotation fluctuations and is supplied to the pressure-side assist cam surface 90A of the pressure-side cam portion 90 and the center-side assist cam surface 60A of the center-side cam portion 60, etc., thereby smoothly lubricating the pressure-side assist cam surface 90A, the center-side assist cam surface 60A, etc.

[0088] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 (i.e., direction D), the first pressure-side recess 92 of the pressure plate 70 and the second center-side recess 64 of the clutch center 40 do not overlap. According to the above aspect, clutch oil scattering toward the clutch center 40 from the first direction D1 is more likely to flow into the first pressure-side recess 92 and the second center-side recess 64. The clutch oil that has flowed into the first pressure-side recess 92 and the second center-side recess 64 flows out of the first pressure-side recess 92 and the second center-side recess 64 during engine rotation fluctuations, etc., and is supplied to the pressure-side assist cam surface 90A of the pressure-side cam portion 90 and the center-side assist cam surface 60A of the center-side cam portion 60, etc., thereby smoothly lubricating the pressure-side assist cam surface 90A, the center-side assist cam surface 60A, etc.

[0089] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 (i.e., direction D), at least a portion of the first pressure-side recess 92 overlaps with the center-side cam hole 43H. According to the above aspect, clutch oil scattering toward the clutch center 40 from the first direction D1 is more likely to flow into the first pressure-side recess 92 through the center-side cam hole 43H. The clutch oil that has flowed into the first pressure-side recess 92 flows out of the first pressure-side recess 92 during engine rotation fluctuations and is supplied to the pressure-side assist cam surface 90A of the pressure-side cam portion 90 and the center-side assist cam surface 60A of the center-side cam portion 60, etc., thereby smoothly lubricating the pressure-side assist cam surface 90A, the center-side assist cam surface 60A, etc.

[0090] 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.

[0091] In the above-described embodiment, the center-side cam portion 60 has the first center-side recess 62 and the second center-side recess 64, but may have at least one of them. Also, the pressure-side cam portion 90 has the first pressure-side recess 92 and the second pressure-side recess 94, but may have at least one of them.

[0092] There are no particular limitations on the shapes of the first center-side recess 62, the second center-side recess 64, the first pressure-side recess 92, and the second pressure-side recess 94. They may be, for example, circular, elliptical, or rectangular.

[0093] In the above-described embodiment, the center-side cam portion 60 has the center-side assist cam surface 60A and the center-side slipper cam surface 60S, but it is sufficient that it has at least the center-side assist cam surface 60A.

[0094] In the above-described embodiment, the pressure-side cam portion 90 has the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S, but it is sufficient that it has at least the pressure-side assist cam surface 90A. [Explanation of symbols]

[0095] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 25 Pressure spring 30 Clutch housing 40 Clutch center 54 Boss section 58 Center side fitting part 60 Center side cam part 60A Center side assist cam surface 60S Center side slipper cam surface 62 First center recess 63 First center side inclined surface 64 Second center recess 65 Second center side inclined surface 70 Pressure Plate 80 Cylindrical part 84 Spring housing 88 Pressure side fitting part 90 Pressure side cam 92 First pressure side recess 93 First pressure side inclined surface 94 Second pressure side recess 95 Second pressure side inclined surface 90A Pressure side assist cam surface 90S Pressure side slipper cam surface

Claims

1. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center 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 or move away from the clutch center and to be able to rotate relative to the clutch center, and that is able to press the input side rotary plate and a plurality of output side rotary plates that are arranged alternately with the input side rotary plate, The pressure plate is The main body and a flange connected to the body and extending radially outward; a plurality of pressure-side cam portions each having a pressure-side assist cam surface that generates a force in a direction that moves the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when the pressure plate rotates relative to the clutch center, and a pressure-side slipper cam surface that moves the pressure plate away from the clutch center in order to decrease the pressing force between the input-side rotating plate and the output-side rotating plate; a pressure-side cam hole that is positioned between the pressure-side cam portions that are adjacent to each other in the circumferential direction and that penetrates the main body, the pressure-side cam portion includes at least the second pressure-side recess out of a first pressure-side recess located between the pressure-side assist cam surface and the pressure-side slipper cam surface in the circumferential direction and recessed in the second direction from the surface of the pressure-side cam portion on the first direction side, and a second pressure-side recess located between the pressure-side assist cam surface and the pressure-side slipper cam surface in the circumferential direction and recessed in the first direction from the surface of the pressure-side cam portion on the second direction side, and a spring accommodating portion located between the pressure-side assist cam surface and the pressure-side slipper cam surface in the circumferential direction, recessed in the first direction from the surface of the pressure-side cam portion on the second direction side, and accommodating a pressure spring, The clutch center is an output shaft holding portion to which the output shaft is connected; a plurality of center-side cam portions each having a center-side assist cam surface that is positioned radially outward of the output shaft holding portion and that generates a force in a direction that moves the pressure plate toward the clutch center in order to increase a pressing force between the input-side rotating plate and the output-side rotating plate when the center-side cam portions rotate relative to the pressure plate, the center-side cam portion has a first center-side recess recessed in the first direction from a surface of the center-side cam portion on the second direction side, When a direction from one of the pressure-side cam portions to the other of the pressure-side cam portions with respect to the circumferential direction is defined as a first circumferential direction, and a direction from the other of the pressure-side cam portions to one of the pressure-side cam portions is defined as a second circumferential direction, the pressure plate is configured to rotate in the first circumferential direction, which is a direction from the pressure-side slipper cam surface of one of the pressure-side cam portions to the pressure-side assist cam surface, the second pressure-side recess is located between the second circumferential edge of the pressure-side slipper cam surface and the spring accommodating portion in the circumferential direction, When viewed from the axial direction of the output shaft, at least a portion of the second pressure-side recess overlaps with the pressure-side slipper cam surface, the first center-side recess has a first center-side inclined surface that is inclined toward the second direction as it goes in the second circumferential direction, the first center-side inclined surface is parallel to the center-side assist cam surface, When viewed from the axial direction of the output shaft, the first center-side inclined surface is entirely exposed from the pressure-side cam hole.

2. 2. The clutch device according to claim 1, wherein the second pressure side recess has a second pressure side inclined surface that is parallel to the pressure side slipper cam surface.

3. 3. The clutch device according to claim 2, wherein the second pressure side inclined surface is inclined so as to approach the second direction as it goes in the second circumferential direction.

4. A clutch device as described in claim 1, wherein the second pressure side recess of the pressure plate and the first center side recess of the clutch center do not overlap when viewed from the axial direction of the output shaft.

Images