Clutch device

Abstract

To achieve weight reduction in the cam section having an assist cam surface and a slipper cam surface. [Solution] The clutch device 10 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, and includes a pressure plate 70 capable of pressing the input side rotating plate 20 and the output side rotating plate 22. The clutch center 40 includes a plurality of center side cam portions 60 having a center side assist cam surface 60A, and each center side cam portion 60 has at least one of a first center side recess 62 recessed in the first direction D1 from the surface 60D2 on the second direction D2 side of the center side cam portion 60, and a second center side recess 64 recessed in the second direction D2 from the surface 60D1 on the first direction D1 side of the center side cam portion 60.

Description

Technical Field

[0001] The present invention relates to a clutch device. More specifically, the present invention relates to a clutch device that arbitrarily transmits or blocks the rotational driving force of an input shaft that is rotationally driven by a prime mover such as an engine to an output shaft.

Background Art

[0002] Conventionally, vehicles such as motorcycles have a clutch device. The clutch device is disposed between the engine and the drive wheel, and transmits or blocks the rotational driving force of the engine to the drive wheel. The clutch device generally includes a plurality of input-side rotating plates that rotate by the rotational driving force of the engine, and a plurality of output-side rotating plates connected to an output shaft that transmits the rotational driving force to the drive wheel. The input-side rotating plates and the output-side rotating plates are alternately arranged in the stacking direction, and the transmission or blocking of the rotational driving force is performed by pressing and separating the input-side rotating plates and the output-side rotating plates.

[0003] For example, Patent Document 1 discloses a clutch device including a clutch center (clutch member) that holds an output-side rotating plate (passive-side clutch plate), and a pressure plate (pressure member) provided so as to be able to approach and separate from the clutch center. The pressure plate is configured to be able to press the input-side rotating plate and the output-side rotating plate. Thus, in the clutch device, the clutch center and the pressure plate are assembled and used.

[0004] Further, the clutch center and the pressure plate of the clutch device of Patent Document 1 include an assist cam surface that generates a force in a direction to approach the pressure plate to the clutch center when the rotational driving force of the engine can be transmitted to the output shaft, thereby increasing the pressing force between the input-side rotating plate and the output-side rotating plate, and a slipper cam surface that separates the pressure plate from the clutch center when the rotational speed of the clutch center exceeds the rotational speed of the pressure plate, thereby reducing the pressing force between the input-side rotating plate and the output-side rotating plate.

Prior Art Documents

[0005] [Patent Document 1] Patent No. 5847551 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, the cam portion of the clutch center and pressure plate, which includes the assist cam surface and the slipper cam surface, has a relatively large thickness. Therefore, as the cam portion increases in size, its weight also increases, leading to the problem of increased overall clutch device weight. Since clutch devices are mounted on vehicles such as motorcycles, a relatively lightweight design is preferable.

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

[0008] The clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input shaft to an output shaft, and 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 holds a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates and rotates together with the output shaft, and a pressure plate that is provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which can press the input-side rotating plates and the output-side rotating plates. The clutch center comprises an output shaft holding portion to which the output shaft is connected, and a plurality of center-side cam portions located radially outside the output shaft holding portion and having a center-side assist cam surface that, when rotated relative to the pressure plate, generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input-side rotating plates and the output-side rotating plates. 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 center-side cam portion has at least one of a first center-side recess that is recessed in the first direction from the surface of the center-side cam portion on the second direction side, and a second center-side recess that is recessed in the second direction from the surface of the center-side cam portion on the first direction side.

[0009] According to the clutch device of the present invention, the center-side cam portion has at least one of a first center-side recess that is recessed in a first direction from the second direction side surface of the center-side cam portion and a second center-side recess that is recessed in a second direction from the first direction side surface of the center-side cam portion. In this way, since the center-side cam portion has at least one of the first center-side recess and the second center-side recess, the center-side cam portion is lighter compared to the case in which it does not have these recesses. Because the clutch device is equipped with a lighter clutch center, the overall weight reduction of the clutch device is achieved.

[0010] Furthermore, another clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input shaft to an output shaft, 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 holds a plurality of output-side rotating plates arranged alternately with the input-side rotating plates and is rotationally driven together with the output shaft; and a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and capable of pressing the input-side rotating plates and the output-side rotating plates. The pressure plate is located radially outward from the output shaft and has a plurality of pressure-side cam portions having pressure-side assist cam surfaces that, when rotated relative to the clutch center, generate a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input-side rotating plates and the output-side rotating plates. 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 pressure-side cam portion has at least one of a first pressure-side recess that recesses in the second direction from the surface of the pressure-side cam portion on the first direction side, and a second pressure-side recess that recesses in the first direction from the surface of the pressure-side cam portion on the second direction side, and when viewed from the axial direction of the output shaft, at least a part of the first pressure-side recess overlaps with the pressure-side assist cam surface.

[0011] In another clutch device according to the present invention, the pressure-side cam portion has at least one of a first pressure-side recess that recesses in a second direction from the surface of the pressure-side cam portion in a first direction and a second pressure-side recess that recesses in a first direction from the surface of the pressure-side cam portion in a second direction. Thus, since the pressure-side cam portion has at least one of the first pressure-side recess and the second pressure-side recess, the pressure-side cam portion is lighter compared to the case in which it does not have these recesses. The clutch device is equipped with a lighter pressure plate, thus achieving overall weight reduction of the clutch device. [Effects of the Invention]

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

[0013] [Figure 1] Figure 1 is a cross-sectional view of a clutch device according to one embodiment. [Figure 2] Figure 2 is a perspective view of a clutch center according to one embodiment. [Figure 3] Figure 3 is a plan view of a clutch center according to one embodiment. [Figure 4] Figure 4 is a perspective view of a clutch center according to one embodiment. [Figure 5] Figure 5 is a plan view of a clutch center according to one embodiment. [Figure 6] Figure 6 is a perspective view of a pressure plate according to one embodiment. [Figure 7] Figure 7 is a plan view of a pressure plate according to one embodiment. [Figure 8] Figure 8 is a perspective view of a pressure plate according to one embodiment. [Figure 9] Figure 9 is a plan view of a pressure plate according to one embodiment. [Figure 10] Figure 10 is a side view of a pressure plate according to one embodiment. [Figure 11] Figure 11 is a plan view showing a clutch center and a pressure plate assembled according to one embodiment. [Figure 12] Figure 12 is a plan view showing a clutch center and a pressure plate assembled according to one embodiment. [Figure 13A] Figure 13A is a schematic diagram illustrating the operation of the center-side assist cam surface and the pressure-side assist cam surface. [Figure 13B]FIG. 13B is a schematic diagram for explaining the operation of the center-side slipper cam surface and the pressure-side slipper cam surface. [Figure 14] FIG. 14 is a cross-sectional view of the center-side cam portion according to an embodiment. [Figure 15] FIG. 15 is a cross-sectional view of the pressure-side cam portion according to an embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0014] Hereinafter, embodiments of the clutch device according to the present invention will be described with reference to the drawings. Note that the embodiments described here are not intended to particularly limit the present invention. Also, members and parts having the same function are denoted by the same reference numerals, and redundant descriptions are omitted or simplified as appropriate.

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

[0016] In the following description, the direction in which the pressure plate 70 of the clutch device 10 approaches and moves away from the clutch center 40 is 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 7), 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 7). In this embodiment, the axial direction of the output shaft 15, the axial direction of the clutch housing 30, the axial direction of the clutch center 40, and the axial direction of the pressure plate 70 are the same as direction D. Furthermore, the pressure plate 70 and the clutch center 40 rotate in 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.

[0017] 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.

[0018] 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 motor vehicle or motorcycle.

[0019] As shown in Figure 1, the output shaft 15 is equipped with a push rod 16A in its hollow section 15H and a push member 16B provided adjacent to the push rod 16A. The hollow section 15H functions as a passage for clutch oil. The clutch oil flows inside the output shaft 15, i.e., inside the hollow section 15H. The push rod 16A and the push member 16B are slidably mounted inside the hollow section 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 by operating the clutch operating lever, it slides inside the hollow section 15H and presses the push member 16B in a second direction D2. A part 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 that clutch oil can flow within the hollow portion 15H.

[0020] The clutch housing 30 is made of an aluminum alloy. 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.

[0021] 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.

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

[0023] The input-side rotating plate 20 is a component that is pressed against the output-side rotating plate 22. The input-side rotating plate 20 is a flat plate formed in an annular shape. The input-side rotating plate 20 is formed by punching out an annular shape from a thin sheet of SPCC (cold-rolled steel sheet) material. 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 with a depth of several micrometers to tens of micrometers are formed between the friction material to hold clutch oil.

[0024] 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 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 arranged alternately in direction D. The clutch center 40 is rotationally driven together with the output shaft 15.

[0025] 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.

[0026] 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 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.

[0027] 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 of the clutch center 40 along the outer peripheral surface 45A of the outer peripheral wall 45, a plurality of spline grooves 48 formed between adjacent center-side fitting teeth 47 and extending in the axial direction of the clutch center 40, and an oil discharge hole 49. The center-side fitting teeth 47 hold the output-side rotating plate 22. The 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 fitting teeth 47 protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45. The oil discharge holes 49 are formed to penetrate the outer peripheral wall 45 radially. The oil discharge holes 49 are formed between adjacent center-side fitting teeth 47. That is, the oil discharge holes 49 are formed in the spline grooves 48. The oil discharge holes 49 are formed on the side of the center-side cam portion 60. The oil discharge holes 49 are formed on the side of the center-side slipper cam surface 60S of the center-side cam portion 60. The oil discharge holes 49 are formed on the second circumferential direction S2 side of the center-side slipper cam surface 60S. The oil discharge holes 49 are formed on the first circumferential direction S1 side of the boss portion 54, which will be described later. In this embodiment, two oil discharge holes 49 are formed at three locations in the circumferential direction S of the outer peripheral wall 45. The oil discharge holes 49 are arranged at equal intervals in the circumferential direction S. The oil discharge hole 49 connects the inside and outside of the clutch center 40. The oil discharge hole 49 is a hole that discharges the clutch oil that has flowed into the clutch center 40 from the output shaft 15 to the outside of the clutch center 40.

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

[0029] The output-side rotating plate 22 is a component that is pressed against the input-side rotating plate 20. The output-side rotating plate 22 is a flat plate formed in an annular shape. The output-side rotating plate 22 is formed by punching out an annular shape from a thin sheet material made of SPCC material. Grooves with a depth of several micrometers to several tens of micrometers are formed on the front and back surfaces of the output-side rotating plate 22 to hold clutch oil. The front and back surfaces of the output-side rotating plate 22 are each subjected to a surface hardening treatment to improve wear resistance. The friction material provided on the input-side rotating plate 20 may be provided on the output-side rotating plate 22 instead of the input-side rotating plate 20, or it may be provided on both the input-side rotating plate 20 and the output-side rotating plate 22.

[0030] The center-side cam portion 60 is formed in a 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 (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22, or slipper torque, which is a force that causes the input-side rotating plate 20 and the output-side rotating plate 22 to separate early and transition to a half-clutch state. The center-side cam portion 60 is formed to protrude from the base wall 43 in a second direction D2. As shown in Figure 3, the center-side cam portions 60 are arranged at equal intervals in the circumferential direction S of the clutch center 40. In this embodiment, the clutch center 40 has three center-side cam portions 60, but the number of center-side cam portions 60 is not limited to three.

[0031] As shown in Figure 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 that moves the pressure plate 70 closer to 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 it rotates relative to the pressure plate 70. In this embodiment, when the above force is generated, the position of the pressure plate 70 relative to the clutch center 40 does not change, and 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 move the pressure plate 70 away 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 it rotates relative to the pressure plate 70. In adjacent center cam portions 60 with respect to the circumferential direction S, the center assist cam surface 60A of one center cam portion 60L and the center slipper cam surface 60S of the other center cam portion 60M are arranged facing each other in the circumferential direction S.

[0032] As shown in Figure 2, the center cam portion 60 has a first center recess 62 that is recessed in the first direction D1 from the surface 60D2 of the center cam portion 60 on the second direction D2 side. The first center recess 62 is located on the second circumferential direction S2 side of the center slipper cam surface 60S. As shown in Figure 5, when viewed from the axial direction (i.e., direction D) of the output shaft 15, at least a portion of the first center recess 62 overlaps with the center assist cam surface 60A. As shown in Figure 14, the first center recess 62 has a first center inclined surface 63 parallel to the center assist cam surface 60A. The first center inclined surface 63 is inclined so that it is directed toward the second direction D2 as it goes toward the second circumferential direction S2.

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

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

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

[0036] As shown in Figure 2, the clutch center 40 is provided with a plurality (three in this embodiment) of 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 of the clutch center 40.

[0037] 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 of the outer peripheral wall 45. The center-side fitting portion 58 is configured to be slidably fitted onto the pressure-side fitting portion 88 (see Figure 6), which will be described later. The inner diameter of the center-side fitting portion 58 is formed with a fitting tolerance that allows the 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. In this embodiment, for example, the center-side fitting portion 58 is formed with an inner diameter that is 0.1 mm larger than the outer diameter of the pressure-side fitting portion 88. The dimensional tolerance between the inner diameter of the center-side fitting portion 58 and the outer diameter of the pressure-side fitting portion 88 is set appropriately according to the amount of clutch oil to be circulated, but is, for example, 0.1 mm or more and 0.5 mm or less.

[0038] 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 of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0039] As shown in Figure 1, the pressure plate 70 is provided so as to be able to move closer to or further 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 positioned concentrically with the clutch center 40 and the clutch housing 30. The pressure plate 70 has a body 72 and a flange 98 that is connected to the outer peripheral edge of the body 72 on the second direction D2 side and extends radially outward. The body 72 protrudes further in the first direction D1 than the flange 98. The flange 98 is located radially outward from the cylindrical portion 80 (see Figure 6), which will be described later. The pressure plate 70 holds a plurality of output side rotating plates 22 that are arranged alternately with the input side rotating plate 20. The flange 98 is configured to be able to press against the input side rotating plate 20 and the output side rotating plate 22.

[0040] As shown in Figure 6, 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 8).

[0041] The cylindrical portion 80 is formed in a cylindrical shape. The cylindrical portion 80 is formed integrally with the pressure-side cam portion 90. The cylindrical portion 80 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 from the flange 98 in the first direction D1. As shown in Figure 7, the pressure-side cam portions 90 are arranged at equal intervals in the circumferential direction S of the pressure plate 70. In this embodiment, the pressure plate 70 has three pressure-side cam portions 90, but the number of pressure-side cam portions 90 is not limited to three.

[0043] As shown in Figure 7, the pressure-side cam portion 90 is located radially outward of the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also Figure 9) 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 that moves the pressure plate 70 closer to 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 it rotates relative to the clutch center 40. 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 it rotates relative to the clutch center 40. 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] As shown in Figure 6, the pressure-side cam portion 90 has a first pressure-side recess 92 that recesses in the second direction D2 from the surface 90D1 on the first direction D1 side of the pressure-side cam portion 90. The first pressure-side recess 92 is located on the first circumferential direction S1 side of the pressure-side slipper cam surface 90S. As shown in Figure 9, when viewed from the axial direction (i.e., direction D) of the output shaft 15, at least a portion of the first pressure-side recess 92 overlaps with the pressure-side assist cam surface 90A. As shown in Figure 15, the first pressure-side recess 92 has a first pressure-side inclined surface 93 parallel to the pressure-side assist cam surface 90A. The first pressure-side inclined surface 93 is inclined so that it moves toward the first direction D1 as it moves toward the first circumferential direction S1.

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

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

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

[0048] Here, the operation of the center-side cam portion 60 and the pressure-side cam portion 90 will be explained. When the engine speed increases and the rotational driving force input to the input gear 35 and clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, a rotational force in the first circumferential direction S1 is applied to the pressure plate 70, as shown in Figure 13A. As a result, the operation of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A generates a force in the first direction D1 on the pressure plate 70. This increases the contact force between the input-side rotating plate 20 and the output-side rotating plate 22. Note that in Figure 13A, the first center-side recess 62 and other parts are omitted from the illustration.

[0049] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and clutch housing 30, resulting in back torque, a first rotational force in the circumferential direction S1 is applied to the clutch center 40, as shown in Figure 13B. As a result, the action of the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S moves the pressure plate 70 in the second direction D2, releasing the contact force between the input-side rotating plate 20 and the output-side rotating plate 22. This prevents malfunctions in the engine and transmission caused by back torque. Note that in Figure 13B, the first center-side recess 62 and other components are omitted from the illustration.

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

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

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

[0053] As shown in Figures 8 and 9, the spring housing portion 84 is formed in the pressure-side cam portion 90. The spring housing portion 84 is located between the first pressure-side recess 92 and the second pressure-side recess 94. The spring housing portion 84 is formed to recess 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.

[0054] 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 of spring steel wound in a spiral shape.

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

[0056] 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 a 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. The stopper plate 100 is formed in a substantially triangular shape in plan view.

[0057] Here, when the pressure plate 70 contacts the stopper plate 100, the contact area between the pressure-side slipper cam surface 90S and the center-side slipper cam surface 60S is 50% to 90% of the area of ​​the pressure-side slipper cam surface 90S, and 50% to 90% of the area of ​​the center-side slipper cam surface 60S, respectively. Also, when the pressure plate 70 contacts the stopper plate 100, the pressure spring 25 is separated from the side wall of the spring housing 84. That is, the pressure spring 25 is not sandwiched between the boss portion 54 and the spring housing 84, and excessive stress on the boss portion 54 is suppressed.

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

[0059] Next, the operation of the clutch device 10 in this embodiment will be described. As described above, the clutch device 10 is positioned between the engine and the transmission of the motorcycle, and the driver operates the clutch lever to transmit and interrupt the rotational driving force of the engine to the transmission.

[0060] In the clutch device 10, if the motorcycle operator does not operate the clutch lever, the clutch release mechanism (not shown) does not press the push rod 16A, so the pressure plate 70 presses the input side rotating plate 20 by the biasing force (elastic force) of the pressure spring 25. As a result, the clutch center 40 rotates in the ON state, with the input side rotating plate 20 and the output side rotating plate 22 pressed against each other and frictionally coupled. That is, the rotational driving force of the engine is transmitted to the clutch center 40 and the output shaft 15 rotates.

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

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

[0063] In the clutch-off state, the clutch oil flowing through the hollow portion H of the output shaft 15 and flowing out from the tip portion 15T of the output shaft 15 is guided into the clutch center 40, similar to the clutch-on state. At this time, the pressure plate 70 is separated from the clutch center 40, so the amount of engagement with the center-side fitting portion 58 and the pressure-side fitting portion 88 is reduced. As a result, the clutch oil in the cylindrical portion 80 flows more actively to the outside of the clutch center 40 and flows to various parts inside the clutch device 10. In particular, the clutch oil can be actively guided between the input-side rotating plate 20 and the output-side rotating plate 22, which are separated from each other.

[0064] Furthermore, when the driver releases the clutch operating lever while the clutch is in the OFF state, the pressure on the pressure plate 70 via the push member 16B by the clutch release mechanism (not shown) is released, and the pressure plate 70 is displaced in a direction approaching the clutch center 40 (first direction D1) by the biasing force of the pressure spring 25.

[0065] As described above, according to the clutch device 10 of this embodiment, the center-side cam portion 60 has at least one of a first center-side recess 62 that is recessed in the first direction D1 from the surface 60D2 of the center-side cam portion 60 on the second direction D2 side, and a second center-side recess 64 that is recessed in the second direction D2 from the surface D1 of the center-side cam portion 60 on the first direction D1 side. Thus, since the center-side cam portion 60 has at least one of the first center-side recess 62 and the second center-side recess 64, the center-side cam portion 60 is lighter compared to the case in which it does not have these recesses. Since the clutch device 10 is equipped with a lighter clutch center 40, the overall weight reduction of the clutch device 10 is achieved.

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

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

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

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

[0070] In the clutch device 10 of this embodiment, the clutch center 40 is configured to rotate in a first circumferential direction S1, which is 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, and the first center-side inclined surface 63 is inclined toward the second direction D2 as it moves toward the second circumferential direction S2. According to the above embodiment, even if clutch oil accumulates in the first center-side recess 62, the clutch oil accumulated in the first center-side recess 62 flows out in the second circumferential direction S2 along the first center-side inclined surface 63.

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

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

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

[0074] In the clutch device 10 of this embodiment, the oil passage 53 is formed in a spline groove 48 that penetrates the outer peripheral wall 45. According to the above embodiment, since the clutch oil flows along the spline groove, the clutch oil can be supplied to the output side rotating plate 22 and the input side rotating plate 20 in a balanced manner.

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

[0076] According to the clutch device 10 of this embodiment, the pressure-side cam portion 90 has at least one of a first pressure-side recess 92 that recesses in the second direction D2 from the surface 90D1 of the pressure-side cam portion 90 on the first direction D1 side, and a second pressure-side recess 94 that recesses in the first direction D1 from the surface 90DS of the pressure-side cam portion 90 on the second direction D2 side. Thus, since the pressure-side cam portion 90 has at least one of the first pressure-side recess 92 and the second pressure-side recess 94, the pressure-side cam portion 90 is lighter compared to the case in which it does not have these recesses. The clutch device 10 is equipped with a lighter pressure plate 70, thus achieving overall weight reduction of the clutch device 10.

[0077] In the clutch device 10 of this embodiment, the pressure-side cam portion 90 has a first pressure-side recess 92 and a second pressure-side recess 94. According to the above embodiment, the pressure-side cam portion 90 can be made even lighter.

[0078] In the clutch device 10 of this embodiment, the pressure plate 70 is formed in the pressure-side cam portion 90 so as to be recessed from a second direction D2 to a first direction D1 and includes a spring housing portion 84 that houses a pressure spring 25 that biases the pressure plate 70 in the first direction D1, and the spring housing portion 84 is located between the first pressure-side recess 92 and the second pressure-side recess 94. According to the above embodiment, the pressure-side cam portion 90 can be made even lighter.

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

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

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

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

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

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

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

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

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

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

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

[0090] 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.

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

[0092] The shapes of the first center-side recess 62, the second center-side recess 64, the first pressure-side recess 92, and the second pressure-side recess 94 are not particularly limited. They may be, for example, circular, elliptical, or rectangular.

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

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

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

Claims

[Claim 1] A clutch device for transmitting or interrupting the rotational driving force of an input shaft to an output shaft, A clutch center is housed in a clutch housing that holds a plurality of input-side rotating plates which are rotated by the rotational drive of the input shaft, and which rotates together with the output shaft, The clutch center is provided to be able to approach or move away from it and to be able to rotate relative to it, and the pressure plate is capable of pressing the input side rotating plate and a plurality of output side rotating plates arranged alternately with the input side rotating plate, The clutch center is, The output shaft holding part to which the output shaft is connected, The device comprises a plurality of center-side cam portions located radially outward from the output shaft holding portion, and having center-side assist cam surfaces that, when rotated relative to the pressure plate, generate a force in a direction that brings the pressure plate closer to the clutch center in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate, When the 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 center-side cam portion has a first center-side recess that is recessed in the first direction from the second direction side surface of the center-side cam portion, and a second center-side recess that is recessed in the second direction from the first direction side surface of the center-side cam portion. A clutch device wherein the end of the first center-side recess in the first direction is located on the first direction side of the end of the second center-side recess in the second direction.

Images