Clutch device

Abstract

A clutch device 10 comprises a clutch center 40 that is rotationally driven together with an output shaft 15, and a pressure plate 270 that is provided so as to be capable of approaching or separating from the clutch center 40 and rotating relative thereto. The clutch center 40 comprises a plurality of oil discharge holes 49 that are formed in spline grooves 48 so as to penetrate through an outer peripheral wall 45 and are capable of discharging clutch oil flowing on the inner peripheral side of the outer peripheral wall 45 to the outside of the clutch center 40. At least some of the plurality of oil discharge holes 49 provided in one spline groove 48A are offset from each other at positions in the circumferential direction S.

Description

Clutch device

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

[0002] A straddle-type vehicle such as a motorcycle includes a clutch device capable of transmitting and cutting off the rotational driving force of a drive source such as an engine to drive wheels. For example, Patent Document 1 discloses a clutch device including a clutch center that holds an output-side rotating plate, and a pressure plate provided so as to be able to approach and separate from the clutch center. Further, in the clutch device of Patent Document 1, the clutch center has center-side engagement teeth and the pressure plate has pressure-side engagement teeth as portions for holding the output-side rotating plate. Furthermore, an oil discharge hole for discharging clutch oil flowing inside the clutch center to the outside is formed in the clutch center, and the clutch oil is supplied to the input-side rotating plate and the output-side rotating plate through the oil discharge hole.

[0003] Japanese Patent No. 7225461

[0004] By the way, in the technology disclosed in Patent Document 1, the oil discharge hole is provided in a spline groove between adjacent center-side engagement teeth, and it is desired to more effectively supply clutch oil from the oil discharge hole to the input-side rotating plate and the output-side rotating plate.

[0005] The present invention has been made in view of this point, and an object of the present invention is to provide a clutch device that can more effectively supply clutch oil from an oil discharge hole to an input-side rotating plate and an output-side rotating plate.

[0006] The clutch device according to the present invention is a clutch device that transmits or interrupts the rotational driving force of an input shaft, which is rotationally driven by the driving force of a drive source, to an output shaft, and comprises a clutch center housed 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 which rotates together with the output shaft, and a pressure plate that is provided so as to be able to approach or move away from the clutch center and so as to be able to rotate relative to it, and which is able to press the input-side rotating plates and a plurality of output-side rotating plates arranged alternately with the input-side rotating plates, wherein the clutch center is connected to an output shaft holding part The clutch center comprises an outer peripheral wall located radially outward from the output shaft holding portion, a plurality of center-side fitting teeth arranged circumferentially that hold the output-side rotating plate and protrude radially outward from the outer peripheral surface of the outer peripheral wall, a plurality of spline grooves formed between adjacent center-side fitting teeth, and a plurality of oil discharge holes formed in the spline grooves so as to penetrate the outer peripheral wall, which are capable of discharging clutch oil flowing on the inner circumferential side of the outer peripheral wall to the outside of the clutch center, wherein at least some of the plurality of oil discharge holes provided in one of the spline grooves are offset from each other in the circumferential direction.

[0007] According to the clutch device of the present invention, at least some of the multiple oil discharge holes provided in a single spline groove are offset from each other in the circumferential direction. In this embodiment, since more clutch oil can be discharged from the multiple oil discharge holes provided in a single spline groove over a wide area in the circumferential direction to the outside of the clutch center, clutch oil can be supplied more effectively to the input side rotating plate and the output side rotating plate.

[0008] Another clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input shaft, which is rotationally driven by the driving force of a drive source, to an output shaft, comprising: a clutch center housed 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 which rotates together with the output shaft; and a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which can press the input-side rotating plates and a plurality of output-side rotating plates arranged alternately with the input-side rotating plates, wherein the pressure plate extends in the axial direction of the output shaft, and the output The clutch plate comprises an outer peripheral wall formed in an annular shape when viewed from the axial direction of the force axis, a plurality of pressure-side fitting teeth arranged in the circumferential direction that hold the output-side rotating plate and protrude radially outward from the outer peripheral surface of the outer peripheral wall, a plurality of spline grooves formed between adjacent pressure-side fitting teeth, and a plurality of oil discharge holes formed in the spline grooves so as to penetrate the outer peripheral wall, which are capable of discharging clutch oil flowing on the inner circumferential side of the outer peripheral wall to the outside of the pressure plate, wherein at least some of the plurality of oil discharge holes provided in one of the spline grooves are offset from each other in the circumferential direction.

[0009] In another clutch device according to the present invention, at least some of the multiple oil discharge holes provided in a single spline groove are offset from each other in the circumferential direction. According to the above embodiment, since more clutch oil can be discharged from the multiple oil discharge holes provided in a single spline groove over a wide area in the circumferential direction to the outside of the pressure plate, clutch oil can be supplied more effectively to the input side rotating plate and the output side rotating plate.

[0010] According to the present invention, a clutch device can be provided that can more effectively supply clutch oil from the oil discharge hole to the input side rotating plate and the output side rotating plate.

[0011] Figure 1 is a cross-sectional view of a clutch device according to the first embodiment. Figure 2 is a perspective view of a clutch center according to the first embodiment. Figure 3 is a plan view of a clutch center according to the first embodiment. Figure 4 is a side view of a clutch center according to the first embodiment. Figure 5 is a perspective view of a pressure plate according to the first embodiment. Figure 6 is a plan view of a pressure plate according to the first embodiment. Figure 7A is a schematic diagram illustrating the operation of the center-side assist cam surface and the pressure-side assist cam surface. Figure 7B is a schematic diagram illustrating the operation of the center-side slipper cam surface and the pressure-side slipper cam surface. Figure 8 is a side view of a clutch center according to the first modified example. Figure 9 is a side view of a clutch center according to the second modified example. Figure 10A is a plan view of a clutch center according to the third modified example. Figure 10B is a side view of a clutch center according to the third modified example. Figure 11 is a side view of a clutch center according to the fourth modified example. Figure 12 is a cross-sectional view of a clutch device according to the second embodiment. Figure 13 is a perspective view of a clutch center according to the second embodiment. Figure 14 is a plan view of the clutch center according to the second embodiment. Figure 15 is a perspective view of the pressure plate according to the second embodiment. Figure 16 is a plan view of the pressure plate according to the second embodiment. Figure 17 is a side view of the pressure plate according to the second embodiment. Figure 18 is a side view of the pressure plate according to the first modification. Figure 19 is a side view of the pressure plate according to the second modification. Figure 20A is a plan view of the pressure plate according to the third modification. Figure 20B is a side view of the pressure plate according to the third modification. Figure 21 is a side view of the pressure plate according to the fourth modification.

[0012] Hereinafter, embodiments of the clutch device according to the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for members and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0013] <First Embodiment> Figure 1 is a cross-sectional view of a clutch device 10 according to the first embodiment. The clutch device 10 is installed in a saddle-type vehicle such as a motorcycle. The clutch device 10 is a device that transmits or interrupts the rotational driving force of an input shaft (crankshaft), which is rotated by the driving force of an engine, which is the driving source of a motorcycle, to an output shaft 15. The clutch device 10 is a device for transmitting or interrupting the rotational driving force of the input shaft to the drive wheel (rear wheel) via the output shaft 15. The clutch device 10 is positioned between the engine and the transmission.

[0014] In the following description, the direction in which the pressure plate 70 of the clutch device 10 approaches and moves away from the clutch center 40 is denoted as direction D, the direction in which the pressure plate 70 approaches the clutch center 40 is denoted as the first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is denoted as the second direction D2. Furthermore, the circumferential direction of the clutch center 40 and the pressure plate 70 is denoted as the circumferential direction S, the direction from one pressure-side cam portion 90 toward the other pressure-side cam portion 90 (the direction from one center-side cam portion 60 toward the other center-side cam portion 60) is denoted as the first circumferential direction S1 (see Figure 2), and the direction from the other pressure-side cam portion 90 toward the one pressure-side cam portion 90 (the direction from the other center-side cam portion 60 toward the one center-side cam portion 60) is denoted as the second circumferential direction S2 (see Figure 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. Furthermore, the pressure plate 70 and the clutch center 40 rotate in the 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 direction is merely defined for the convenience of explanation and does not limit the installation configuration of the clutch device 10 in any way, nor does it limit the present invention in any way.

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

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

[0017] As shown in Figure 1, the output shaft 15 includes a push rod 16A and a push member 16B provided adjacent to the push rod 16A in its hollow portion 15H. The hollow portion 15H functions as a passage for clutch oil. The clutch oil flows inside the output shaft 15, i.e., inside the hollow portion 15H. The push rod 16A and the push member 16B are slidably mounted inside the hollow portion 15H of the output shaft 15. One end of the push rod 16A (the left end in the figure) is connected to the clutch operating lever (not shown) of a motorcycle, and operation of the clutch operating lever causes it to slide inside the hollow portion 15H and press the push member 16B in the second direction D2. The push rod 16A may also be configured to slide inside the hollow portion 15H by a servo motor. 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 be thinner than the inner diameter of the hollow portion 15H, ensuring the flow of clutch oil within the hollow portion 15H.

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

[0019] As shown in Figure 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 rivets 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates due to the rotational drive of the engine's input shaft. The input gear 35 rotates independently of the output shaft 15 and integrally with the clutch housing 30.

[0020] The input-side rotating plate 20 is rotationally driven by the rotational drive of the input shaft. As shown in Figure 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 (i.e., direction D) of the clutch housing 30. The input-side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0021] The input-side rotating plate 20 is a component 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 molded from aluminum die-cast. A friction material (not shown) consisting of multiple pieces of paper is attached to the front and back surfaces of the input-side rotating plate 20. Grooves several hundred micrometers deep are formed between the friction material to hold clutch oil.

[0022] As shown in Figure 1, the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is positioned concentrically with the clutch housing 30. The clutch center 40 has a cylindrical body 42 and a center-side flange 68 extending radially outward from the outer peripheral edge of the body 42. The clutch center 40 holds an input-side rotating plate 20 and a plurality of output-side rotating plates 22 that are alternately arranged in direction D. The clutch center 40 rotates together with the output shaft 15.

[0023] As shown in Figure 2, the center flange 68 extends radially outward from the outer peripheral edge of the main body 42. The center flange 68 is located radially outward from the center cam portion 60, which will be described later. The center flange 68, together with the pressure flange 98 of the pressure plate 70, which will be described later, clamps the input rotating plate 20 and the output rotating plate 22. The center flange 68 is provided so as to be able to press the input rotating plate 20 and the output rotating plate 22. The center flange 68 is a member that applies pressing force to the input rotating plate 20 and the output rotating plate 22.

[0024] As shown in Figure 2, the main body 42 comprises an annular base wall 43, an outer peripheral wall 45 located radially outward from the base wall 43 and extending toward a second direction D2, an output shaft holding portion 50 provided in the center of the base wall 43, a plurality of center-side cam portions 60 connected to the base wall 43 and the outer peripheral wall 45, and a center-side fitting portion 58.

[0025] The output shaft holder 50 is formed in a cylindrical shape. The output shaft holder 50 has an insertion hole 51 into which the output shaft 15 is inserted and spline fitted. The insertion hole 51 is formed through the base wall 43. Multiple spline grooves are formed along the axial direction (i.e., direction D) on the inner circumferential surface 50A of the output shaft holder 50 that forms the insertion hole 51. The output shaft 15 is connected to the output shaft holder 50.

[0026] As shown in Figure 2, the outer peripheral wall 45 of the clutch center 40 is positioned radially outward from the output shaft holding portion 50. The outer peripheral wall 45 is located radially outward from the center-side cam portion 60. A spline fitting portion 46 is provided on the 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 (i.e., direction D) of the clutch center 40 along the outer peripheral surface 45A of the outer peripheral wall 45, and a plurality of spline grooves 48 formed between adjacent center-side fitting teeth 47 and extending in the axial direction (i.e., direction D) of the clutch center 40. The center-side fitting teeth 47 hold the output-side rotating plate 22. The plurality of center-side fitting teeth 47 are arranged in the circumferential direction S. The plurality of center-side fitting teeth 47 are formed at equal intervals in the circumferential direction S. The plurality of center-side fitting teeth 47 are formed to have the same shape. The center-side mating teeth 47 protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45. The multiple spline grooves 48 are arranged in the circumferential direction S. The multiple spline grooves 48 are formed at equal intervals in the circumferential direction S. The multiple spline grooves 48 are formed in the same shape. In this embodiment, the length of the spline groove 48 in the circumferential direction S is longer than the length of the center-side mating teeth 47 in the circumferential direction S, but they may be the same or shorter.

[0027] As shown in Figures 2 and 4, the clutch center 40 is provided with a plurality of oil discharge holes 49. The oil discharge holes 49 are formed between adjacent center-side fitting teeth 47. The oil discharge holes 49 are formed in spline grooves 48 so as to penetrate the outer peripheral wall 45. The oil discharge holes 49 penetrate the outer peripheral wall 45 radially. The oil discharge holes 49 communicate the inside and outside of the clutch center 40. The oil discharge holes 49 are configured to discharge clutch oil flowing on the inner circumference side of the outer peripheral wall 45 to the outside of the clutch center 40. In this embodiment, the oil discharge holes 49 are formed in a circular shape, but the shape is not particularly limited.

[0028] As shown in Figure 4, the multiple oil discharge holes 49 provided in one spline groove 48A include a first oil discharge hole 49A and a second oil discharge hole 49B. The first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are offset from each other in the circumferential direction S. The first oil discharge hole 49A is located on the first circumferential direction S1 side than the second oil discharge hole 49B. The first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are offset from each other in the axial direction (i.e., direction D) of the output shaft 15. The first oil discharge hole 49A is located on the first direction D1 side than the second oil discharge hole 49B. When viewed radially, the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are located between the end 60SD1 of the center slipper cam surface 60S in the first direction D1 and the end 60SD2 of the center slipper cam surface 60S in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. When viewed radially, all of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) are located in the portion 48AD1 on the center flange 68 side when the spline groove 48A is divided into two equal parts in the axial direction (i.e., direction D) of the output shaft 15. Here, the first oil discharge hole 49A and the second oil discharge hole 49B are not located in the portion 48AD2 on the pressure plate 70 side when the spline groove 48A is divided into two equal parts in the axial direction (i.e., direction D) of the output shaft 15. The first oil discharge hole 49A and the second oil discharge hole 49B are located on the first circumferential direction S1 side with respect to the center line 48AL that passes through the center of the circumferential direction S of the spline groove 48A and extends in the axial direction (i.e., direction D) of the output shaft, but they may also be located on the second circumferential direction S2 side. As shown in Figure 3, the second oil discharge hole 49B provided in one spline groove 48A is located between the end portion 60SS1 of the center-side slipper cam surface 60S in the first circumferential direction S1 and the end portion 60SS2 of the center-side slipper cam surface 60S in the second circumferential direction S2 with respect to the circumferential direction S. Similarly, the first oil discharge hole 49A may also be located between the end portion 60SS1 and the end portion 60SS2 with respect to the circumferential direction S.

[0029] As shown in Figure 4, the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are formed along the center slipper cam surface 60S. When viewed radially, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A is parallel to the center slipper cam surface 60S. When viewed radially, the straight line LC1 passing through the center of the first oil discharge hole 49A and the center of the second oil discharge hole 49B provided in one spline groove 48A is parallel to the center slipper cam surface 60S.

[0030] As shown in Figure 4, when viewed from the radial direction, at least a portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center slipper cam surface 60S. When viewed from the radial direction, more than half of the circumferential S portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center slipper cam surface 60S.

[0031] 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 spline fitting to the center-side fitting teeth 47 and spline groove 48 of the clutch center 40. Another portion of the output-side rotating plate 22 is held by the pressure-side fitting teeth 77 (see Figure 5), 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 (i.e., direction D) of the clutch center 40. The output-side rotating plate 22 is provided so as to be rotatable integrally with the clutch center 40.

[0032] The output-side rotating plate 22 is a component 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 sheet 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 it may be provided on both the input-side rotating plate 20 and the output-side rotating plate 22.

[0033] The center-side cam portion 60 is formed in a trapezoidal shape and has a cam surface consisting of an inclined surface that constitutes an assist & slipper (registered trademark) mechanism that generates assist torque, which is a force that increases the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22, or slipper torque, which is a force that decreases the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22, causing the system to transition to a half-clutch state. The half-clutch state is a state between the state in which the clutch is fully engaged and the state in which the clutch is fully disengaged. As shown in Figure 2, the center-side cam portion 60 is formed to protrude in the second direction D2 from the surface 43D2 of the base wall 43 on the second direction D2 side. 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.

[0034] As shown in Figures 2 and 3, the center-side cam portion 60 is located radially outward from 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 (here, a first direction D1) in the direction from the pressure plate 70 toward the clutch center 40 in order to increase 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, such as when accelerating. In this embodiment, when the above force is generated, the position of the pressure plate 70 relative to the clutch center 40 does not change, and it is not necessary for the pressure plate 70 to physically approach the clutch center 40. However, the pressure plate 70 may be physically displaced relative to the clutch center 40. The center slipper cam surface 60S is configured to separate the pressure plate 70 from the clutch center 40 in order to reduce the pressing force (contact force) between the input rotating plate 20 and the output rotating plate 22 when the clutch center 40 rotates relative to the pressure plate 70, such as when decelerating. In adjacent center cam portions 60 with respect to the circumferential direction S, the center assist cam surface 60A of one center cam portion 60M and the center slipper cam surface 60S of the other center cam portion 60L are arranged facing each other in the circumferential direction S.

[0035] As shown in Figures 2 and 3, the clutch center 40 is provided with a plurality of (three in this embodiment) boss portions 54. 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. The boss portions 54 have screw holes 54H into which bolts 28 (see Figure 1) are inserted. The screw holes 54H extend in the axial direction (i.e., direction D) of the clutch center 40.

[0036] As shown in Figure 2, the center-side fitting portion 58 is located radially outward from the output shaft holding portion 50. The center-side fitting portion 58 is located radially outward from the center-side cam portion 60. The center-side fitting portion 58 is located on the second direction D2 side of the center-side cam portion 60. The center-side fitting portion 58 is formed on the inner circumferential surface 45B of the outer circumferential wall 45. The center-side fitting portion 58 is configured to be slidably fitted onto the pressure-side fitting portion 88 (see Figure 5), which will be described later. The inner diameter of the center-side fitting portion 58 is formed with a fitting tolerance that allows the flow of clutch oil flowing out from the tip portion 15T of the output shaft 15 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.

[0037] As shown in Figures 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 through between adjacent center-side cam portions 60. The center-side cam hole 43H is formed between the center-side assist cam surface 60A and the boss portion 54 of the center-side cam portion 60. When viewed from the axial direction (i.e., direction D) of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0038] As shown in Figure 1, the pressure plate 70 is provided so as to be able to approach or move away from the clutch center 40 and to be able to rotate relative to it. The pressure plate 70 is configured to be able to press against 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. As shown in Figure 5, the pressure plate 70 has a main body 72 and a pressure side 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 further in the first direction D1 than the pressure side flange 98. The pressure side flange 98 is located radially outward from the cylindrical portion 80 which will be described later. The pressure plate 70 holds a plurality of output side rotating plates 22 which are arranged alternately with the input side rotating plate 20. The pressure side flange 98 is configured to be able to press against the input side rotating plate 20 and the output side rotating plate 22.

[0039] As shown in Figures 5 and 6, 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 from the pressure-side cam portion 90, which will be described later. The pressure-side flange 98, together with the center-side flange 68 of the clutch center 40, clamps 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 against the input-side rotating plate 20 and the output-side rotating plate 22. The pressure-side flange 98 is a member that applies pressing force to the input-side rotating plate 20 and the output-side rotating plate 22.

[0040] As shown in Figure 5, the main body 72 comprises a cylindrical portion 80, a plurality of pressure-side cam portions 90, a pressure-side fitting portion 88, and a spring housing portion 84 (see also Figure 6).

[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 houses the tip portion 15T (see Figure 1) of the output shaft 15. The release bearing 18 (see Figure 1) is housed in the cylindrical portion 80. The cylindrical portion 80 is the part that receives the pressing force from the push member 16B. The cylindrical portion 80 is the part that receives the 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 trapezoidal shape and has a cam surface consisting of an inclined surface that slides against the center-side cam portion 60 to generate assist torque or slipper torque, forming an assist & slipper (registered trademark) mechanism. The pressure-side cam portion 90 is formed to protrude in the first direction D1 from the pressure-side flange 98. As shown in Figure 5, 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 Figure 5, 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 Figure 6) and a pressure-side slipper cam surface 90S. The pressure-side assist cam surface 90A is configured to be in contact with the center-side assist cam surface 60A. The pressure-side assist cam surface 90A is configured to generate a force in the direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force (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, such as when accelerating. The pressure-side slipper cam surface 90S is configured to be in contact with the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to separate the pressure plate 70 from the clutch center 40 in order to reduce the pressing force (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, such as when decelerating. In adjacent pressure-side cam sections 90 with respect to the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam section 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam section 90M are arranged facing each other in the circumferential direction S.

[0044] Here, the operations 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 becomes transmissible to the output shaft 15 via the clutch center 40, as shown in FIG. 7A, a rotational force in a first circumferential direction S1 is applied to the pressure plate 70. Therefore, due to the action of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A, a force in a first direction D1 is generated on the pressure plate 70. This is configured to increase the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22.

[0045] On the other hand, when back torque occurs as the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30, as shown in FIG. 7B, a rotational force in the first circumferential direction S1 is applied to the clutch center 40. Therefore, due to the action of the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S, the pressure plate 70 is moved in a second direction D2 to release the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22. This makes it possible to avoid malfunctions to the engine and transmission caused by back torque.

[0046] As shown in FIG. 5, the pressure-side fitting portion 88 is located radially outward of the pressure-side cam portion 90. The pressure-side fitting portion 88 is located closer to the second direction D2 side than the pressure-side cam portion 90. The pressure-side fitting portion 88 is configured to be slidably fitted internally into the center-side fitting portion 58 (see FIG. 2).

[0047] As shown in FIGS. 5 and 6, the pressure plate 70 has a pressure-side cam hole 73H penetrating through a part of the main body 72 and the pressure-side 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 the 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 so as 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 FIG. 6, when viewed from the axial direction of the pressure plate 70 (i.e., direction D), the pressure-side assist cam surface 90A overlaps with a part of the pressure-side cam hole 73H.

[0048] As shown in FIG. 5, the pressure plate 70 includes a plurality of pressure-side fitting teeth 77 disposed on the pressure-side flange 98. The pressure-side fitting teeth 77 hold the output-side rotating plate 22. The pressure-side fitting teeth 77 protrude from the pressure-side flange 98 toward the first direction D1. The pressure-side fitting teeth 77 are located radially outward of the cylindrical portion 80, and are located radially outward of the pressure-side cam portions 90. The pressure-side fitting teeth 77 are located radially outward of the pressure-side cam portions 90. The pressure-side fitting teeth 77 are located radially outward of the pressure-side fitting portion 88. The plurality of pressure-side fitting teeth 77 are arranged in the circumferential direction S. The plurality of pressure-side fitting teeth 77 are arranged at equal intervals in the circumferential direction S. In the present embodiment, since some of the pressure-side fitting teeth 77 are removed, the interval between these portions is widened, while the other adjacent pressure-side fitting teeth 77 are arranged at equal intervals.

[0049] As shown in Figures 5 and 6, the spring housing portion 84 is formed in the pressure-side cam portion 90. The spring housing portion 84 is located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S. The spring housing portion 84 is formed to be recessed from the second direction D2 to the first direction D1. The spring housing portion 84 is formed in an elliptical shape. The spring housing portion 84 houses the pressure spring 25 (see Figure 1). An insertion hole 84H is formed through the spring housing portion 84 into which the boss portion 54 (see Figure 2) is inserted. That is, the insertion hole 84H is formed through the pressure-side cam portion 90. The insertion hole 84H is formed in an elliptical shape.

[0050] As shown in Figure 1, the pressure spring 25 is housed in the spring housing 84. The pressure spring 25 is held by a boss portion 54 inserted into an insertion hole 84H of the spring housing 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 made by winding spring steel in a spiral shape.

[0051] As shown in Figure 1, the stopper plate 100 is provided so as to be in contact with the pressure plate 70. The stopper plate 100 is a member that prevents the pressure plate 70 from moving away from the clutch center 40 in the second direction D2 by a predetermined distance or more. The stopper plate 100 is fixed to the boss portion 54 of the clutch center 40 by bolts 28. The pressure plate 70 is fixed to the boss portion 54 of the clutch center 40 by bolts 28 tightened 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 positioned in the spring housing portion 84.

[0052] A predetermined amount of clutch oil is filled inside the clutch device 10. The clutch oil flows into the clutch center 40 and pressure plate 70 through the hollow portion 15H of the output shaft 15, 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, etc. The clutch oil absorbs heat and suppresses wear of the friction material. The clutch device 10 of this embodiment is a so-called wet multi-plate friction clutch device.

[0053] As described above, in the clutch device 10 of this embodiment, at least a portion of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) are offset from each other in the circumferential direction S. According to the above embodiment, a larger amount of clutch oil can be discharged from the multiple oil discharge holes 49 provided in one spline groove 48A to the outside of the clutch center 40 over a wide area in the circumferential direction S, thereby enabling a more effective supply of clutch oil to the input side rotating plate 20 and the output side rotating plate 22.

[0054] In the clutch device 10 of this embodiment, at least some of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) are offset from each other in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, a larger amount of clutch oil can be discharged from the multiple oil discharge holes 49 provided in one spline groove 48A to the outside of the clutch center 40 over a wide area in both the circumferential direction S and the axial direction (i.e., direction D).

[0055] In the clutch device 10 of this embodiment, when viewed from the radial direction, at least a portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center slipper cam surface 60S. According to the above embodiment, since clutch oil tends to accumulate around the center slipper cam surface 60S inside the clutch center 40, more clutch oil can be discharged through the oil discharge hole 49.

[0056] In the clutch device 10 of this embodiment, when viewed from the radial direction, more than half of the circumferential S portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center slipper cam surface 60S. According to the above embodiment, the degree of freedom in the position in which the oil discharge hole 49 is provided is increased.

[0057] In the clutch device 10 of this embodiment, a plurality of oil discharge holes 49 (here, the first oil discharge hole 49A and the second oil discharge hole 49B) provided in a single spline groove 48A are formed along the center-side slipper cam surface 60S. According to the above embodiment, clutch oil tends to accumulate around the center-side slipper cam surface 60S inside the clutch center 40, so more clutch oil can be discharged through the oil discharge holes 49.

[0058] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through at least two of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) is parallel to the center slipper cam surface 60S. According to the above embodiment, clutch oil accumulated around the center slipper cam surface 60S can be efficiently discharged through the oil discharge holes 49.

[0059] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through all of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) is parallel to the center slipper cam surface 60S. According to the above embodiment, clutch oil accumulated around the center slipper cam surface 60S can be efficiently discharged through the oil discharge holes 49.

[0060] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 that passes through all the centers of the multiple oil discharge holes 49 provided in one spline groove 48A is parallel to the center slipper cam surface 60S. According to the above embodiment, the clutch oil accumulated around the center slipper cam surface 60S can be discharged more efficiently through the oil discharge holes 49.

[0061] In the clutch device 10 of this embodiment, when viewed from the radial direction, the multiple oil discharge holes 49 provided in one spline groove 48A are located between the end 60SD1 of the center slipper cam surface 60S in the first direction D1 and the end 60SD2 of the center slipper cam surface 60S in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil accumulated around the center slipper cam surface 60S can be efficiently discharged through the oil discharge holes 49.

[0062] In the clutch device 10 of this embodiment, when viewed radially, all of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) are located in the portion 48AD1 on the center flange 68 side when the spline groove 48A is divided into two equal parts in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil can be supplied to a wider area of ​​the output rotating plate 22 and the input rotating plate 20 via the center flange 68.

[0063] In the clutch device 10 of this embodiment, the first oil discharge hole 49A and the second oil discharge hole 49B are located on the first circumferential direction S1 side with respect to the center line 48AL that passes through the center of the circumferential direction S of the spline groove 48A and extends in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, a large amount of clutch oil can be discharged from the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A to a specific part outside the clutch center 40.

[0064] In the clutch device 10 of this embodiment, at least a portion of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the second oil discharge hole 49B) is located between the first circumferential end 60SS1 of the center-side slipper cam surface 60S in the circumferential direction S1 and the second circumferential end 60SS2 of the center-side slipper cam surface 60S in the circumferential direction S2 with respect to the circumferential direction S. According to the above embodiment, clutch oil accumulated around the center-side slipper cam surface 60S can be efficiently discharged through the second oil discharge hole 49B.

[0065] Figure 8 is a side view of the clutch center 40 according to the first modified example. As shown in Figure 8, the plurality of oil discharge holes 49 provided in one spline groove 48A include a first oil discharge hole 49A, a second oil discharge hole 49B, and a third oil discharge hole 49C. The first oil discharge hole 49A and the third oil discharge hole 49C provided in one spline groove 48A are at the same position in the circumferential direction S. The first oil discharge hole 49A is located on the first direction D1 side than the third oil discharge hole 49C. The second oil discharge hole 49B and the third oil discharge hole 49C provided in one spline groove 48A are at the same position in the axial direction (i.e., direction D) of the output shaft 15. The second oil discharge hole 49B is located on the second circumferential direction S2 side than the third oil discharge hole 49C. The third oil discharge hole 49C may be located at a different position in the circumferential direction S than the first oil discharge hole 49A. The third oil discharge hole 49C may be located at a different position in direction D than the second oil discharge hole 49B.

[0066] As shown in Figure 8, when viewed radially, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B is parallel to the center-side slipper cam surface 60S. The straight line LC2 passing through the first oil discharge hole 49A and the third oil discharge hole 49C, and the straight line LC3 passing through the second oil discharge hole 49B and the third oil discharge hole 49C, are not parallel to the center-side slipper cam surface 60S.

[0067] In the clutch device 10 of this embodiment, some of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the third oil discharge hole 49C) are located at the same position in the circumferential direction S. According to the above embodiment, more clutch oil can be discharged from a specific part in the circumferential direction S.

[0068] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B is parallel to the center-side slipper cam surface 60S, while the straight line LC2 passing through the first oil discharge hole 49A and the third oil discharge hole 49C, and the straight line LC3 passing through the second oil discharge hole 49B and the third oil discharge hole 49C are not parallel to the center-side slipper cam surface 60S. According to the above embodiment, clutch oil accumulated around the center-side slipper cam surface 60S can be efficiently discharged through the first oil discharge hole 49A and the second oil discharge hole 49B, and clutch oil inside the clutch center 40 can be further discharged through the third oil discharge hole 49C.

[0069] Figure 9 is a side view of the clutch center 40 according to a second modified example. As shown in Figure 9, the first oil discharge hole 49A provided in one spline groove 48A is located on the first circumferential direction S1 side with respect to the center line 48AL which passes through the center of the circumferential direction S of the spline groove 48A and extends in the axial direction (i.e., direction D) of the output shaft 15. The second oil discharge hole 49B provided in one spline groove 48A is located on the second circumferential direction S2 side with respect to the center line 48AL. Alternatively, the first oil discharge hole 49A may be located on the second circumferential direction S2 side with respect to the center line 48AL, and the second oil discharge hole 49B may be located on the first circumferential direction S1 side with respect to the center line 48AL.

[0070] In the clutch device 10 of this embodiment, the first oil discharge hole 49A is located on the first circumferential direction S1 side with respect to the center line 48AL that passes through the center of the circumferential direction S of the spline groove 48A and extends in the axial direction (i.e., direction D) of the output shaft 15, and the second oil discharge hole 49B is located on the second circumferential direction S2 side with respect to the center line 48AL. According to the above embodiment, a larger amount of clutch oil can be discharged to the outside of the clutch center 40 over a wide area in the circumferential direction S from the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A.

[0071] Figure 10A is a plan view of the clutch center 40 according to the third modified example. Figure 10B is a side view of the clutch center 40 according to the third modified example. As shown in Figure 10B, when viewed radially, the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are located between the end 60AD1 of the center-side assist cam surface 60A in the first direction D1 and the end 60AD2 of the center-side assist cam surface 60A in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. The first oil discharge hole 49A and the second oil discharge hole 49B are located on the second circumferential direction S2 side with respect to the center line 48AL that passes through the center of the circumferential direction S of the spline groove 48A and extends in the axial direction (i.e., direction D) of the output shaft 15, but they may also be located on the first circumferential direction S1 side. As shown in Figure 10A, the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are located between the first circumferential end 60AS1 of the center-side assist cam surface 60A in the circumferential direction S1 and the second circumferential end 60AS2 of the center-side assist cam surface 60A in the circumferential direction S2, with respect to the circumferential direction S.

[0072] As shown in Figure 10B, the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A are formed along the center-side assist cam surface 60A. When viewed radially, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B provided in one spline groove 48A is parallel to the center-side assist cam surface 60A. When viewed radially, the straight line LC1 passing through the center of the first oil discharge hole 49A and the center of the second oil discharge hole 49B provided in one spline groove 48A is parallel to the center-side assist cam surface 60A.

[0073] As shown in Figure 10B, when viewed from the radial direction, at least a portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center-side assist cam surface 60A. When viewed from the radial direction, more than half of the circumferential S portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center-side assist cam surface 60A.

[0074] In the clutch device 10 of this embodiment, when viewed from the radial direction, at least a portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center-side assist cam surface 60A. According to the above embodiment, since clutch oil tends to accumulate around the center-side assist cam surface 60A inside the clutch center 40, more clutch oil can be discharged through the oil discharge hole 49.

[0075] In the clutch device 10 of this embodiment, when viewed from the radial direction, more than half of the circumferential S portion of the spline groove 48A in which the oil discharge hole 49 is formed overlaps with the center-side assist cam surface 60A. According to the above embodiment, the degree of freedom in the position in which the oil discharge hole 49 is provided is increased.

[0076] In the clutch device 10 of this embodiment, a plurality of oil discharge holes 49 (here, the first oil discharge hole 49A and the second oil discharge hole 49B) provided in one spline groove 48A are formed along the center-side assist cam surface 60A. According to the above embodiment, clutch oil tends to accumulate around the center-side assist cam surface 60A inside the clutch center 40, so more clutch oil can be discharged through the oil discharge holes 49.

[0077] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through at least two of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) is parallel to the center-side assist cam surface 60A. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be efficiently discharged through the oil discharge holes 49.

[0078] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through all of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) is parallel to the center-side assist cam surface 60A. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be efficiently discharged through the oil discharge holes 49.

[0079] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 that passes through all the centers of the multiple oil discharge holes 49 provided in one spline groove 48A is parallel to the center-side assist cam surface 60A. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be discharged more efficiently through the oil discharge holes 49.

[0080] In the clutch device 10 of this embodiment, when viewed from the radial direction, the multiple oil discharge holes 49 (here, the first oil discharge hole 49A and the second oil discharge hole 49B) provided in one spline groove 48A are located between the end 60AD1 of the center-side assist cam surface 60A in the first direction D1 and the end 60AD2 of the center-side assist cam surface 60A in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be efficiently discharged through the oil discharge holes 49.

[0081] In the clutch device 10 of this embodiment, at least a portion of the multiple oil discharge holes 49 provided in one spline groove 48A (here, the first oil discharge hole 49A and the second oil discharge hole 49B) are located between the end 60AS1 of the center-side assist cam surface 60A in the first circumferential direction S1 and the end 60AS2 of the center-side assist cam surface 60A in the second circumferential direction S2 with respect to the circumferential direction S. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be efficiently discharged through the oil discharge holes 49.

[0082] Figure 11 is a side view of the clutch center 40 according to a fourth modified example. As shown in Figure 11, when viewed radially, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B is parallel to the center-side assist cam surface 60A. The straight line LC2 passing through the first oil discharge hole 49A and the third oil discharge hole 49C, and the straight line LC3 passing through the second oil discharge hole 49B and the third oil discharge hole 49C, are not parallel to the center-side assist cam surface 60A.

[0083] In the clutch device 10 of this embodiment, when viewed from the radial direction, the straight line LC1 passing through the first oil discharge hole 49A and the second oil discharge hole 49B is parallel to the center-side assist cam surface 60A, while the straight line LC2 passing through the first oil discharge hole 49A and the third oil discharge hole 49C, and the straight line LC3 passing through the second oil discharge hole 49B and the third oil discharge hole 49C are not parallel to the center-side assist cam surface 60A. According to the above embodiment, clutch oil accumulated around the center-side assist cam surface 60A can be efficiently discharged through the first oil discharge hole 49A and the second oil discharge hole 49B, and clutch oil inside the clutch center 40 can be further discharged through the third oil discharge hole 49C.

[0084] <Second Embodiment> Figure 12 is a cross-sectional view showing a part of the clutch device 210 according to the second embodiment. As shown in Figure 12, 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 100. The clutch device 210 of this embodiment is a so-called wet multi-plate friction clutch device.

[0085] As shown in Figure 12, the clutch center 240 is housed in the clutch housing 30. The clutch center 240 is positioned concentrically with the clutch housing 30. The clutch center 240 has a body 242 and a center-side flange 68 extending radially outward from the outer peripheral edge of the body 242. The body 242 has a portion that protrudes in a second direction D2 from the center-side flange 68. The clutch center 240 does not hold the output-side rotating plate 22. The clutch center 240 rotates together with the output shaft 15.

[0086] As shown in Figure 13, the main body 242 includes an output shaft holding portion 50, a plurality of center-side cam portions 60, and a center-side fitting portion 258.

[0087] As shown in Figures 13 and 14, the clutch center 240 is provided with a plurality of (three in this embodiment) boss portions 54. The boss portions 54 are provided on the center-side cam portion 60.

[0088] As shown in Figures 13 and 14, the clutch center 240 has a center-side cam hole 243H that penetrates a portion of the main body 242. The center-side cam hole 243H penetrates the main body 242 in direction D. The center-side cam hole 243H extends from the side of the output shaft holding portion 50 to the center-side flange 68. The center-side cam hole 243H is formed between the center-side assist cam surface 60A and the center-side slipper cam surface 60S of the center-side cam portion 60. When viewed from the axial direction of the clutch center 240, the center-side assist cam surface 60A and a portion of the center-side cam hole 243H overlap.

[0089] As shown in Figure 13, the center-side fitting portion 258 is provided on the main body 242. The center-side fitting portion 258 is located radially outward from the center-side cam portion 60. The center-side fitting portion 258 is located toward the first direction D1 side from the center-side cam portion 60. The center-side fitting portion 258 is configured to be slidably fitted into the pressure-side fitting portion 288 (see Figure 15).

[0090] As shown in Figure 12, the pressure plate 270 is housed in the clutch housing 30. The pressure plate 270 is located on the second direction D2 side of the clutch center 240. The pressure plate 270 is provided so as to be able to move toward or away from the clutch center 240 and to be able to rotate relative to it. The pressure plate 270 is configured to be able to press against the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 270 is arranged concentrically with the clutch center 240 and the clutch housing 30. As shown in Figures 15 and 16, the pressure plate 270 has a cylindrical body 272 and a pressure side flange 98 extending radially outward from the outer peripheral edge of the body 272. The body 272 has a portion that protrudes in the first direction D1 from the pressure side flange 98. The pressure plate 270 holds all of the input side rotating plate 20 and the plurality of output side rotating plates 22 that are arranged alternately in direction D.

[0091] The output-side rotating plate 22 is held by a spline fitting portion 276 of the pressure plate 270, which will be described later. The output-side rotating plate 22 is held by spline fitting to the pressure-side fitting teeth 277 (see Figures 15 and 16) and spline grooves 278 (see Figures 15 and 16) of the pressure plate 270, which will be described later. The output-side rotating plate 22 is provided so as to be displaceable along the axial direction (i.e., direction D) of the pressure plate 270. The output-side rotating plate 22 is provided so as to be rotatable integrally with the pressure plate 270.

[0092] As shown in Figures 15 and 16, the main body 272 comprises an annular base wall 273, an annular outer peripheral wall 275, a cylindrical portion 80 provided in the center of the base wall 273, a plurality of pressure-side cam portions 90 connected to the base wall 273 and the outer peripheral wall 275, a pressure-side fitting portion 288, and a spring housing portion 289 (see Figure 12).

[0093] As shown in Figures 15 and 16, the outer peripheral wall 275 is positioned radially outward from the cylindrical portion 80. The outer peripheral wall 275 is formed in an annular shape when viewed from the axial direction of the output shaft 15. The outer peripheral wall 275 extends in the axial direction (i.e., direction D) of the output shaft 15. A spline fitting portion 276 is provided on the outer peripheral surface 275A of the outer peripheral wall 275. The spline fitting portion 276 has a plurality of pressure-side fitting teeth 277 that extend along the outer peripheral surface 275A of the outer peripheral wall 275 in the axial direction (i.e., direction D) of the pressure plate 270, and a plurality of spline grooves 278 formed between adjacent pressure-side fitting teeth 277 and extending in the axial direction of the pressure plate 270. The pressure-side fitting teeth 277 hold all of the output-side rotating plates 22. The plurality of pressure-side fitting teeth 277 are aligned in the circumferential direction S. Multiple pressure-side mating teeth 277 are formed at equal intervals in the circumferential direction S. Multiple pressure-side mating teeth 277 are formed to have the same shape. The pressure-side mating teeth 277 protrude radially outward from the outer peripheral surface 275A of the outer peripheral wall 275. Multiple spline grooves 278 are arranged in the circumferential direction S. Multiple spline grooves 278 are formed at equal intervals in the circumferential direction S. Multiple spline grooves 278 are formed to have the same shape. In this embodiment, the length of the spline groove 278 in the circumferential direction S is longer than the length of the pressure-side mating teeth 277 in the circumferential direction S, but it may be the same or shorter.

[0094] As shown in Figures 15 and 17, the pressure plate 270 is provided with a plurality of oil discharge holes 279. The oil discharge holes 279 are formed between adjacent pressure-side fitting teeth 277. The oil discharge holes 279 are formed in spline grooves 278 so as to penetrate the outer peripheral wall 275. The oil discharge holes 279 penetrate the outer peripheral wall 275 radially. The oil discharge holes 279 communicate the inside and outside of the pressure plate 270. The oil discharge holes 279 are configured to discharge clutch oil flowing on the inner circumference side of the outer peripheral wall 275 to the outside of the pressure plate 270. In this embodiment, the oil discharge holes 279 are formed in a circular shape, but the shape is not particularly limited.

[0095] As shown in Figure 17, the multiple oil discharge holes 279 provided in one spline groove 278A include a first oil discharge hole 279A and a second oil discharge hole 279B. The first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are offset from each other in the circumferential direction S. The first oil discharge hole 279A is located on the second circumferential direction S2 side than the second oil discharge hole 279B. The first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are offset from each other in the axial direction (i.e., direction D) of the output shaft 15. The first oil discharge hole 279A is located on the second direction D2 side than the second oil discharge hole 279B. When viewed radially, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are located between the end 90AD1 in the first direction D1 and the end 90AD2 in the second direction D2 of the pressure-side assist cam surface 90A with respect to the axial direction (i.e., direction D) of the output shaft 15. When viewed radially, all of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) are located in the portion 278AD2 on the pressure-side flange 98 side when the spline groove 278A is divided into two equal parts in the axial direction (direction D) of the output shaft 15. Here, the first oil discharge hole 279A and the second oil discharge hole 279B are not located in the portion 278AD1 on the clutch center 240 side when the spline groove 278A is divided into two equal parts in the axial direction (direction D) of the output shaft 15. The first oil discharge hole 279A is located on the second circumferential direction S2 side with respect to the center line 278AL which passes through the center of the circumferential direction S of the spline groove 278A and extends in the axial direction (i.e., direction D) of the output shaft 15, and the second oil discharge hole 279B is located on the first circumferential direction S1 side with respect to the center line 278AL. As shown in Figure 16, the first oil discharge hole 279A and the second oil discharge hole 279B, provided in one spline groove 278A, are located between the first circumferential end 90AS1 of the pressure-side assist cam surface 90A in the circumferential direction S1 and the second circumferential end 90AS2 of the pressure-side assist cam surface 90A in the circumferential direction S2, with respect to the circumferential direction S.

[0096] As shown in Figure 17, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are formed along the pressure-side assist cam surface 90A. When viewed radially, the straight line LP1 passing through the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A is parallel to the pressure-side assist cam surface 90A. When viewed radially, the straight line LP1 passing through the center of the first oil discharge hole 279A and the center of the second oil discharge hole 279B provided in one spline groove 278A is parallel to the pressure-side assist cam surface 90A.

[0097] As shown in Figure 17, when viewed from the radial direction, at least a portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side assist cam surface 90A. When viewed from the radial direction, more than half of the circumferential S portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side assist cam surface 90A.

[0098] As shown in Figure 15, the pressure-side fitting portion 288 is located radially outward from the cylindrical portion 80. The pressure-side fitting portion 288 is located radially outward from the pressure-side cam portion 90. The pressure-side fitting portion 288 is located toward the first direction D1 side from the pressure-side cam portion 90. The pressure-side fitting portion 288 is formed on the inner circumferential surface 275B of the outer circumferential wall 275. The pressure-side fitting portion 288 is configured to slidably fit onto the center-side fitting portion 258 (see Figure 13). A gap is formed between the pressure-side fitting portion 288 and the center-side fitting portion 258.

[0099] As shown in Figure 12, the spring housing portion 289 is formed in the pressure-side cam portion 90. The spring housing portion 289 is formed to be recessed from the second direction D2 to the first direction D1. The spring housing portion 289 is formed in a circular shape. The spring housing portion 289 houses the pressure spring 25.

[0100] As shown in Figures 15 and 16, the pressure plate 270 has a pressure-side cam hole 273H that penetrates a portion of the base wall 273. The pressure-side cam hole 273H penetrates the base wall 273 in direction D. The pressure-side cam hole 273H is located radially outward from the cylindrical portion 80. The pressure-side cam hole 273H extends from the side of the cylindrical portion 80 to the outer peripheral wall 275. The pressure-side cam hole 273H is formed through between adjacent pressure-side cam portions 90. The pressure-side cam hole 273H is formed through 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 from the axial direction of the pressure plate 270, the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 273H overlap.

[0101] As described above, in the clutch device 210 of this embodiment, at least a portion of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) are offset from each other in the circumferential direction S. According to the above embodiment, more clutch oil can be discharged from the multiple oil discharge holes 279 provided in one spline groove 278A to the outside of the pressure plate 270 over a wide area in the circumferential direction S, thereby supplying clutch oil to the input side rotating plate 20 and the output side rotating plate 22 more effectively.

[0102] In the clutch device 210 of this embodiment, at least some of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) are offset from each other in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, more clutch oil can be discharged from the multiple oil discharge holes 279 provided in one spline groove 278A to the outside of the pressure plate 270 over a wide area in both the circumferential direction S and the axial direction (i.e., direction D).

[0103] In the clutch device 210 of this embodiment, when viewed from the radial direction, at least a portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil tends to accumulate around the pressure-side assist cam surface 90A inside the pressure plate 270, so more clutch oil can be discharged through the oil discharge hole 279.

[0104] In the clutch device 210 of this embodiment, when viewed from the radial direction, more than half of the circumferential S portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side assist cam surface 90A. According to the above embodiment, the degree of freedom in the position in which the oil discharge hole 279 is provided is increased.

[0105] In the clutch device 210 of this embodiment, a plurality of oil discharge holes 279 (here, the first oil discharge hole 279A and the second oil discharge hole 279B) provided in one spline groove 278A are formed along the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil tends to accumulate around the pressure-side assist cam surface 90A inside the pressure plate 270, so more clutch oil can be discharged through the oil discharge holes 279.

[0106] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 passing through at least two of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) is parallel to the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be efficiently discharged through the oil discharge holes 279.

[0107] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 passing through all of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) is parallel to the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be efficiently discharged through the oil discharge holes 279.

[0108] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 that passes through all the centers of the multiple oil discharge holes 279 provided in one spline groove 278A is parallel to the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be discharged more efficiently through the oil discharge holes 279.

[0109] In the clutch device 210 of this embodiment, when viewed from the radial direction, the multiple oil discharge holes 279 provided in one spline groove 278A are located between the end 90AD1 of the pressure-side assist cam surface 90A in the first direction D1 and the end 90AD2 of the pressure-side assist cam surface 90A in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be efficiently discharged through the oil discharge holes 279.

[0110] In the clutch device 210 of this embodiment, when viewed radially, all of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) are located in the portion 278AD2 on the pressure-side flange 98 side when the spline groove 278A is divided into two equal parts in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil can be supplied to a wider area of ​​the output-side rotating plate 22 and the input-side rotating plate 20 via the pressure-side flange 98.

[0111] In the clutch device 210 of this embodiment, the first oil discharge hole 279A is located on the second circumferential direction S2 side with respect to the center line 278AL which passes through the center of the circumferential direction S of the spline groove 278A and extends in the axial direction (i.e., direction D) of the output shaft 15, and the second oil discharge hole 279B is located on the first circumferential direction S1 side with respect to the center line 278AL. According to the above embodiment, a larger amount of clutch oil can be discharged to the outside of the pressure plate 270 over a wide area in the circumferential direction S from the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A.

[0112] In the clutch device 210 of this embodiment, at least a portion of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) are located between the end 90AS1 of the pressure-side assist cam surface 90A in the first circumferential direction S1 and the end 90AS2 of the pressure-side assist cam surface 90A in the second circumferential direction S2 with respect to the circumferential direction S. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be efficiently discharged through the oil discharge holes 279.

[0113] Figure 18 is a side view of a pressure plate 270 according to the first modified example. As shown in Figure 18, the multiple oil discharge holes 279 provided in one spline groove 278A include a first oil discharge hole 279A, a second oil discharge hole 279B, and a third oil discharge hole 279C. The first oil discharge hole 279A and the third oil discharge hole 279C provided in one spline groove 278A are at the same position in the circumferential direction S. The first oil discharge hole 279A is located on the second direction D2 side than the third oil discharge hole 279C. The second oil discharge hole 279B and the third oil discharge hole 279C provided in one spline groove 278A are at the same position in the axial direction (i.e., direction D) of the output shaft 15. The second oil discharge hole 279B is located on the first circumferential direction S1 side than the third oil discharge hole 279C. The third oil discharge hole 279C may be located at a different position in the circumferential direction S than the first oil discharge hole 279A. The third oil discharge hole 279C may be located at a different position in direction D than the second oil discharge hole 279B.

[0114] As shown in Figure 18, when viewed radially, the straight line LP1 passing through the first oil discharge hole 279A and the second oil discharge hole 279B is parallel to the pressure-side assist cam surface 90A. The straight line LP2 passing through the first oil discharge hole 279A and the third oil discharge hole 279C, and the straight line LP3 passing through the second oil discharge hole 279B and the third oil discharge hole 279C, are not parallel to the pressure-side assist cam surface 90A.

[0115] In the clutch device 210 of this embodiment, some of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the third oil discharge hole 279C) are located at the same position in the circumferential direction S. According to the above embodiment, more clutch oil can be discharged from a specific part in the circumferential direction S.

[0116] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 passing through the first oil discharge hole 279A and the second oil discharge hole 279B is parallel to the pressure-side assist cam surface 90A, while the straight line LP2 passing through the first oil discharge hole 279A and the third oil discharge hole 279C, and the straight line LP3 passing through the second oil discharge hole 279B and the third oil discharge hole 279C are not parallel to the pressure-side assist cam surface 90A. According to the above embodiment, clutch oil accumulated around the pressure-side assist cam surface 90A can be efficiently discharged through the first oil discharge hole 279A and the second oil discharge hole 279B, and clutch oil inside the pressure plate 270 can be further discharged through the third oil discharge hole 279C.

[0117] Figure 19 is a side view of a pressure plate 270 according to a second modified example. As shown in Figure 19, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are located on the second circumferential direction S2 side with respect to the center line 278AL which passes through the center of the circumferential direction S of the spline groove 278A and extends in the axial direction (i.e., direction D) of the output shaft 15. Alternatively, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A may be located on the first circumferential direction S1 side with respect to the center line 278AL.

[0118] In the clutch device 210 of this embodiment, the first oil discharge hole 279A and the second oil discharge hole 279B are located on the second circumferential direction S2 side with respect to the center line 278AL that passes through the circumferential center of the spline groove 278A and extends in the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, a larger amount of clutch oil can be discharged to a specific part outside the pressure plate 270 from the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A.

[0119] Figure 20A is a plan view of the pressure plate 270 according to the third modification. Figure 20B is a side view of the pressure plate 270 according to the third modification. As shown in Figure 20B, when viewed radially, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are located between the end 90SD1 in the first direction D1 and the end 90SD2 in the second direction D2 of the pressure-side slipper cam surface 90S with respect to the axial direction (i.e., direction D) of the output shaft 15. The first oil discharge hole 279A and the second oil discharge hole 279B are located on the first circumferential direction S1 side with respect to the center line 278AL that passes through the center of the circumferential direction S of the spline groove 278A and extends in the axial direction (i.e., direction D) of the output shaft 15, but they may also be located on the second circumferential direction S2 side. As shown in Figure 20A, the second oil discharge hole 279B provided in one spline groove 278A is located between the first circumferential end 90SS1 of the pressure-side slipper cam surface 90S in the circumferential direction S1 and the second circumferential end 90SS2 of the pressure-side slipper cam surface 90S in the circumferential direction S2, with respect to the circumferential direction S.

[0120] As shown in Figure 20B, the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A are formed along the pressure-side slipper cam surface 90S. When viewed radially, the straight line LP1 passing through the first oil discharge hole 279A and the second oil discharge hole 279B provided in one spline groove 278A is parallel to the pressure-side slipper cam surface 90S. When viewed radially, the straight line LP1 passing through the center of the first oil discharge hole 279A and the center of the second oil discharge hole 279B provided in one spline groove 278A is parallel to the pressure-side slipper cam surface 90S.

[0121] As shown in Figure 20B, when viewed radially, at least a portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side slipper cam surface 90S. When viewed radially, more than half of the circumferential S portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side slipper cam surface 90S.

[0122] In the clutch device 210 of this embodiment, when viewed from the radial direction, at least a portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side slipper cam surface 90S. According to the above embodiment, clutch oil tends to accumulate around the pressure-side slipper cam surface 90S inside the pressure plate 270, so more clutch oil can be discharged through the oil discharge hole 279.

[0123] In the clutch device 210 of this embodiment, when viewed from the radial direction, more than half of the circumferential S portion of the spline groove 278A in which the oil discharge hole 279 is formed overlaps with the pressure-side slipper cam surface 90S. According to the above embodiment, the degree of freedom in the position in which the oil discharge hole 279 is provided is increased.

[0124] In the clutch device 210 of this embodiment, a plurality of oil discharge holes 279 (here, the first oil discharge hole 279A and the second oil discharge hole 279B) provided in one spline groove 278A are formed along the pressure-side slipper cam surface 90S. According to the above embodiment, clutch oil tends to accumulate around the pressure-side slipper cam surface 90S inside the pressure plate 270, so more clutch oil can be discharged through the oil discharge holes.

[0125] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 passing through at least two of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) is parallel to the pressure-side slipper cam surface 90S. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be efficiently discharged through the oil discharge holes 279.

[0126] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 passing through all of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the first oil discharge hole 279A and the second oil discharge hole 279B) is parallel to the pressure-side slipper cam surface 90S. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be efficiently discharged through the oil discharge holes 279.

[0127] In the clutch device 210 of this embodiment, when viewed from the radial direction, the straight line LP1 that passes through all the centers of the multiple oil discharge holes 279 provided in one spline groove 278A is parallel to the pressure-side slipper cam surface 90S. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be discharged more efficiently through the oil discharge holes 279.

[0128] In the clutch device 210 of this embodiment, when viewed from the radial direction, the multiple oil discharge holes 279 (here, the first oil discharge hole 279A and the second oil discharge hole 279B) provided in one spline groove 278A are located between the end 90SD1 of the pressure-side slipper cam surface 90S in the first direction D1 and the end 90SD2 of the pressure-side slipper cam surface 90S in the second direction D2 with respect to the axial direction (i.e., direction D) of the output shaft 15. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be efficiently discharged through the oil discharge holes 279.

[0129] In the clutch device 210 of this embodiment, at least a portion of the multiple oil discharge holes 279 provided in one spline groove 278A (here, the second oil discharge hole 279B) is located between the first circumferential end 90SS1 of the pressure-side slipper cam surface 90S in the circumferential direction S1 and the second circumferential end 90SS2 of the pressure-side slipper cam surface 90S in the circumferential direction S2 with respect to the circumferential direction S. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be efficiently discharged through the second oil discharge hole 279B.

[0130] Figure 21 is a side view of the pressure plate 270 according to a fourth modification. As shown in Figure 21, when viewed radially, the straight line LP1 passing through the first oil discharge hole 279A and the second oil discharge hole 279B is parallel to the pressure-side slipper cam surface 90S. The straight line LP2 passing through the first oil discharge hole 279A and the third oil discharge hole 279C, and the straight line LP3 passing through the second oil discharge hole 279B and the third oil discharge hole 279C, are not parallel to the pressure-side slipper cam surface 90S.

[0131] In the clutch device 210 of this embodiment, when viewed radially, the straight line passing through the first oil discharge hole 279A and the second oil discharge hole 279B is parallel to the pressure-side slipper cam surface, while the straight line passing through the first oil discharge hole and the third oil discharge hole, and the straight line passing through the second oil discharge hole and the third oil discharge hole are not parallel to the pressure-side slipper cam surface. According to the above embodiment, clutch oil accumulated around the pressure-side slipper cam surface 90S can be efficiently discharged through the first oil discharge hole 279A and the second oil discharge hole 279B, and clutch oil inside the pressure plate 270 can be further discharged through the third oil discharge hole 279C.

[0132] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0133] In the first embodiment described above, the clutch center 40 and the pressure plate 70 were configured to hold the output-side rotating plate 22, but the invention is not limited to this configuration. For example, the clutch center 40 alone may be configured to hold the output-side rotating plate 22.

[0134] The technology disclosed herein can be applied to various types of clutch devices. In the embodiments described above, a so-called internal-cut type clutch device is described as an example, in which the pressure plates 70 and 270 are located on the opposite side of the clutch housing 30, with the clutch centers 40 and 240 in between, in the axial direction (i.e., direction D) of the output shaft 15, but the technology is not limited thereto. For example, it can also be similarly applied to a so-called external-cut type clutch device in which the pressure plates 70 and 270 are located between the clutch centers 40 and 240 and the clutch housing 30, in the axial direction of the output shaft 15.

[0135] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 30 Clutch housing 40 Clutch center 47 Center side mating teeth 48 Spline groove 49 Oil discharge hole 60 Center side cam section 60A Center side assist cam surface 60S Center side slipper cam surface 68 Center side flange 70 Pressure plate 90 Pressure side cam section 90A Pressure side assist cam surface 90S Pressure side slipper cam surface 98 Pressure side flange 210 Clutch device 240 Clutch center 270 Pressure plate 277 Pressure side mating teeth 278 Spline groove 279 Oil discharge hole

Claims

1. A clutch device for transmitting or interrupting the rotational driving force of an input shaft, which is rotationally driven by the driving force of a drive source, to an output shaft, comprising: a clutch center housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and which rotates together with the output shaft; and a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which can press the input-side rotating plates and a plurality of output-side rotating plates arranged alternately with the input-side rotating plates, wherein the clutch center comprises: an output shaft holding portion to which the output shaft is connected; an outer peripheral wall located radially outward from the output shaft holding portion; a plurality of center-side fitting teeth arranged in the circumferential direction that hold the output-side rotating plates and protrude radially outward from the outer peripheral surface of the outer peripheral wall; a plurality of spline grooves formed between adjacent center-side fitting teeth; and a plurality of oil discharge holes formed in the spline grooves so as to penetrate the outer peripheral wall, which can discharge clutch oil flowing on the inner circumferential side of the outer peripheral wall to the outside of the clutch center, A clutch device in which at least some of the multiple oil discharge holes provided in one of the spline grooves are offset from each other in the circumferential direction.

2. The clutch device according to claim 1, wherein at least some of the plurality of oil discharge holes provided in one of the spline grooves are offset from each other in the axial direction of the output shaft.

3. The clutch device according to claim 1, wherein some of the oil discharge holes provided in one of the spline grooves are in the same position in the circumferential direction.

4. The clutch device according to claim 1, wherein the clutch center is located radially outward of the output shaft holding portion and comprises a plurality of center-side cam portions having a center-side assist cam surface that generates a force toward the clutch center from the pressure plate in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when rotated 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 rotating plate and the output-side rotating plate, and when viewed radially, at least a portion of the spline groove in which the oil discharge hole is formed overlaps with the center-side slipper cam surface or the center-side assist cam surface.

5. The clutch device according to claim 4, wherein, when viewed from the radial direction, more than half of the circumferential portion of the spline groove in which the oil discharge hole is formed overlaps with the center slipper cam surface or the center assist cam surface.

6. The clutch device according to claim 4, wherein the plurality of oil discharge holes provided in one spline groove are formed along the center slipper cam surface.

7. The clutch device according to claim 6, wherein, when viewed from the radial direction, a straight line passing through at least two of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the center slipper cam surface.

8. The clutch device according to claim 6, wherein, when viewed from the radial direction, the straight line passing through all of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the center slipper cam surface.

9. The clutch device according to claim 8, wherein, when viewed from the radial direction, a straight line passing through all the centers of each of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the center slipper cam surface.

10. The clutch device according to claim 6, wherein, when the direction in which the pressure plate approaches the clutch center is defined as the first direction, and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the plurality of oil discharge holes provided in one spline groove are located between the end of the center-side slipper cam surface in the first direction and the end of the center-side slipper cam surface in the second direction with respect to the axial direction of the output shaft.

11. The clutch device according to claim 4, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole, a second oil discharge hole, and a third oil discharge hole, wherein, when viewed from the radial direction, the line passing through the first oil discharge hole and the second oil discharge hole is parallel to the center-side slipper cam surface, and the line passing through the first oil discharge hole and the third oil discharge hole and the line passing through the second oil discharge hole and the third oil discharge hole are not parallel to the center-side slipper cam surface.

12. The clutch device according to claim 4, wherein the plurality of oil discharge holes provided in one of the spline grooves are formed along the center-side assist cam surface.

13. The clutch device according to claim 12, wherein, when viewed from the radial direction, a straight line passing through at least two of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the center-side assist cam surface.

14. The clutch device according to claim 12, wherein, when viewed from the radial direction, the straight line passing through all of the multiple oil discharge holes provided in one of the spline grooves is parallel to the center-side assist cam surface.

15. The clutch device according to claim 14, wherein, when viewed from the radial direction, a straight line passing through all the centers of each of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the center-side assist cam surface.

16. The clutch device according to claim 12, wherein, when the direction in which the pressure plate approaches the clutch center is defined as the first direction and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the plurality of oil discharge holes provided in one spline groove are located between the end of the center-side assist cam surface in the first direction and the end of the center-side assist cam surface in the second direction with respect to the axial direction of the output shaft.

17. The clutch device according to claim 4, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole, a second oil discharge hole, and a third oil discharge hole, wherein, when viewed from the radial direction, the line passing through the first oil discharge hole and the second oil discharge hole is parallel to the center-side assist cam surface, and the line passing through the first oil discharge hole and the third oil discharge hole and the line passing through the second oil discharge hole and the third oil discharge hole are not parallel to the center-side assist cam surface.

18. The clutch device according to claim 1, wherein the clutch center comprises a center-side flange capable of pressing the input-side rotating plate and the output-side rotating plate, and when viewed radially, all of the plurality of oil discharge holes provided in one of the spline grooves are located on the portion on the center-side flange side when the spline groove is divided into two equal parts in the axial direction of the output shaft.

19. The clutch device according to claim 1, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole and a second oil discharge hole, and the first oil discharge hole and the second oil discharge hole are located on one or the other side in the circumferential direction with respect to a center line passing through the circumferential center of the spline groove and extending in the axial direction of the output shaft.

20. The clutch device according to claim 1, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole and a second oil discharge hole, the first oil discharge hole is located on one side in the circumferential direction with respect to a center line passing through the circumferential center of the spline groove and extending in the axial direction of the output shaft, and the second oil discharge hole is located on the other side in the circumferential direction with respect to the center line.

21. The clutch device according to claim 1, wherein the clutch center is located radially outward of the output shaft holding portion and comprises a plurality of center-side cam portions having a center-side assist cam surface that generates a force toward the clutch center from the pressure plate in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when rotated 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 rotating plate and the output-side rotating plate, and the clutch center and the pressure plate are configured to rotate in the first circumferential direction when the direction from one to the other is defined as the first circumferential direction and the direction from the other to the one is defined as the second circumferential direction, and at least a portion of the plurality of oil discharge holes provided in one of the spline grooves are located between the first circumferential end of the center-side assist cam surface and the second circumferential end of the center-side assist cam surface with respect to the circumferential direction.

22. The clutch device according to claim 1, wherein the clutch center is located radially outward of the output shaft holding portion and comprises a plurality of center-side cam portions having a center-side assist cam surface that generates a force toward the clutch center from the pressure plate in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when rotated 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 rotating plate and the output-side rotating plate, and the clutch center and the pressure plate are configured to rotate in the first circumferential direction when the direction from one to the other is defined as the first circumferential direction and the direction from the other to the one is defined as the second circumferential direction, and at least a portion of the plurality of oil discharge holes provided in one of the spline grooves are located between the first circumferential end of the center-side slipper cam surface and the second circumferential end of the center-side slipper cam surface with respect to the circumferential direction.

23. A clutch device for transmitting or interrupting the rotational driving force of an input shaft, which is rotationally driven by the driving force of a drive source, to an output shaft, comprising: a clutch center housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and which rotates together with the output shaft; and a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which can press the input-side rotating plates and a plurality of output-side rotating plates arranged alternately with the input-side rotating plates, wherein the pressure plate comprises: an outer peripheral wall extending in the axial direction of the output shaft and formed in an annular shape when viewed from the axial direction of the output shaft; a plurality of circumferentially arranged pressure-side fitting teeth that hold the output-side rotating plates and are formed to protrude radially outward from the outer peripheral surface of the outer peripheral wall; and a plurality of spline grooves formed between adjacent pressure-side fitting teeth. A clutch device comprising: a plurality of oil discharge holes formed in the spline groove so as to penetrate the outer peripheral wall, which are capable of discharging clutch oil flowing on the inner circumferential side of the outer peripheral wall to the outside of the pressure plate, wherein at least some of the plurality of oil discharge holes provided in one of the spline grooves are offset from each other in the circumferential direction.

24. The clutch device according to claim 23, wherein at least some of the plurality of oil discharge holes provided in one spline groove are offset from each other in the axial direction of the output shaft.

25. The clutch device according to claim 23, wherein some of the oil discharge holes provided in one of the spline grooves are in the same position in the circumferential direction.

26. The clutch device according to claim 23, wherein the pressure plate is located radially inward of the outer peripheral wall and comprises a plurality of pressure-side cam portions having a pressure-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when rotated 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 rotating plate and the output-side rotating plate, and when viewed radially, at least a portion of the spline groove in which the oil discharge hole is formed overlaps with the pressure-side slipper cam surface or the pressure-side assist cam surface.

27. The clutch device according to claim 26, wherein, when viewed from the radial direction, more than half of the circumferential portion of the spline groove in which the oil discharge hole is formed overlaps with the pressure-side slipper cam surface or the pressure-side assist cam surface.

28. The clutch device according to claim 26, wherein the plurality of oil discharge holes provided in one of the spline grooves are formed along the pressure-side slipper cam surface.

29. The clutch device according to claim 28, wherein, when viewed from the radial direction, a straight line passing through at least two of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the pressure-side slipper cam surface.

30. The clutch device according to claim 28, wherein, when viewed from the radial direction, the straight line passing through all of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the pressure-side slipper cam surface.

31. The clutch device according to claim 30, wherein, when viewed from the radial direction, a straight line passing through all the centers of each of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the pressure-side slipper cam surface.

32. The clutch device according to claim 28, wherein, when the direction in which the pressure plate approaches the clutch center is defined as the first direction and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the plurality of oil discharge holes provided in one spline groove are located between the end of the pressure-side slipper cam surface in the first direction and the end of the pressure-side slipper cam surface in the second direction with respect to the axial direction of the output shaft.

33. The clutch device according to claim 26, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole, a second oil discharge hole, and a third oil discharge hole, wherein, when viewed from the radial direction, the line passing through the first oil discharge hole and the second oil discharge hole is parallel to the pressure-side slipper cam surface, and the line passing through the first oil discharge hole and the third oil discharge hole and the line passing through the second oil discharge hole and the third oil discharge hole are not parallel to the pressure-side slipper cam surface.

34. The clutch device according to claim 26, wherein the plurality of oil discharge holes provided in one of the spline grooves are formed along the pressure-side assist cam surface.

35. The clutch device according to claim 34, wherein, when viewed from the radial direction, a straight line passing through at least two of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the pressure-side assist cam surface.

36. The clutch device according to claim 34, wherein, when viewed from the radial direction, the straight line passing through all of the multiple oil discharge holes provided in one of the spline grooves is parallel to the pressure-side assist cam surface.

37. The clutch device according to claim 36, wherein, when viewed from the radial direction, a straight line passing through all the centers of each of the plurality of oil discharge holes provided in one of the spline grooves is parallel to the pressure-side assist cam surface.

38. The clutch device according to claim 34, wherein, when the direction in which the pressure plate approaches the clutch center is defined as the first direction and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the plurality of oil discharge holes provided in one spline groove are located between the end of the pressure-side assist cam surface in the first direction and the end of the pressure-side assist cam surface in the second direction with respect to the axial direction of the output shaft.

39. The clutch device according to claim 26, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole, a second oil discharge hole, and a third oil discharge hole, wherein, when viewed from the radial direction, the line passing through the first oil discharge hole and the second oil discharge hole is parallel to the pressure-side assist cam surface, and the line passing through the first oil discharge hole and the third oil discharge hole and the line passing through the second oil discharge hole and the third oil discharge hole are not parallel to the pressure-side assist cam surface.

40. The clutch device according to claim 23, wherein the pressure plate comprises a pressure-side flange capable of pressing the input-side rotating plate and the output-side rotating plate, and when viewed radially, all of the plurality of oil discharge holes provided in one of the spline grooves are located on the pressure-side flange side portion when the spline groove is divided into two equal parts in the axial direction of the output shaft.

41. The clutch device according to claim 23, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole and a second oil discharge hole, and the first oil discharge hole and the second oil discharge hole are located on one or the other side in the circumferential direction with respect to a center line passing through the circumferential center of the spline groove and extending in the axial direction of the output shaft.

42. The clutch device according to claim 23, wherein the plurality of oil discharge holes provided in one spline groove include a first oil discharge hole and a second oil discharge hole, the first oil discharge hole is located on one side in the circumferential direction with respect to a center line passing through the circumferential center of the spline groove and extending in the axial direction of the output shaft, and the second oil discharge hole is located on the other side in the circumferential direction with respect to the center line.

43. The clutch device according to claim 23, wherein the pressure plate comprises a plurality of pressure-side cam portions having a pressure-side assist cam surface located radially inward of the outer peripheral wall and having a pressure-side assist cam surface that generates a force in a direction toward the clutch center in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate when it 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 rotating plate and the output-side rotating plate, wherein the clutch center and the pressure plate are configured to rotate in the first circumferential direction when the direction from one to the other is defined as the first circumferential direction and the direction from the other to the one is defined as the second circumferential direction, and at least a portion of the plurality of oil discharge holes provided in one of the spline grooves are located between the first circumferential end of the pressure-side assist cam surface and the second circumferential end of the pressure-side assist cam surface with respect to the circumferential direction.

44. The clutch device according to claim 23, wherein the pressure plate comprises a plurality of pressure-side cam portions having a pressure-side assist cam surface located radially inward of the outer peripheral wall and, when rotated relative to the clutch center, a pressure-side assist cam surface that generates a force in a direction toward the clutch center from the pressure plate to increase the pressing force between the input-side rotating plate and the output-side rotating plate, and a pressure-side slipper cam surface that separates the pressure plate from the clutch center to decrease the pressing force between the input-side rotating plate and the output-side rotating plate, wherein the clutch center and the pressure plate are configured to rotate in the first circumferential direction when the direction from one to the other is defined as the first circumferential direction and the direction from the other to the one is defined as the second circumferential direction, and at least a portion of the plurality of oil discharge holes provided in one of the spline grooves are located between the first circumferential end of the pressure-side slipper cam surface and the second circumferential end of the pressure-side slipper cam surface with respect to the circumferential direction.

Images