Clutch device

Abstract

To provide a clutch device in which the pressure side cam portion having a pressure side assist cam surface and a pressure side slipper cam surface in the pressure plate is made lighter. [Solution] The clutch device 10 includes a clutch center 40 that rotates together with the output shaft 15, a pressure plate 70 that is movable toward or away from the clutch center 40 and rotatable relative to it, and a lifter plate 100 fixed to the pressure plate 70, wherein at least a portion of the boss portion 84 of the pressure plate 70 is located within a recess 99 formed in the pressure-side cam portion 90, and is located to the right R of the left surface 73L of the base wall 73, and is located to the left L of the left surface 90L of the pressure-side cam portion 90 that partitions the recess 99 and is located opposite the right surface 90R of the pressure-side cam portion 90.

Description

Technical Field

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

Background Art

[0002] Saddle-type vehicles such as motorcycles include a clutch device that can transmit and cut off the rotational driving force of a driving source such as an engine to a driving wheel. For example, in Patent Document 1, an input shaft connected to the engine side, an output shaft connected to the driving wheel side, a clutch center connected to the output shaft, a pressure plate that can approach or separate from the clutch center, a plurality of input-side rotating plates held by a clutch housing that rotates by the rotational driving force of the input shaft, and a plurality of output-side rotating plates alternately arranged with the input-side rotating plates are disclosed.

[0003] Further, the pressure plate of the clutch device in Patent Document 1 has a pressure-side assist cam surface that generates a force in the direction from the pressure plate toward the clutch center when the rotational driving force of the engine can be transmitted to the output shaft, increasing the pressing force between the input-side rotating plate and the output-side rotation, and a pressure-side 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, reducing the pressing force between the input-side rotating plate and the output-side rotation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, the pressure-side cam section has a relatively large thickness. Therefore, the larger the pressure-side cam section, the greater the weight, which leads to a problem of increased overall clutch device weight. Since clutch devices are mounted on vehicles such as motorcycles, a relatively lightweight design is preferable.

[0006] 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 pressure-side cam portion having a pressure-side assist cam surface and a pressure-side slipper cam surface in the pressure plate is reduced. [Means for solving the problem]

[0007] 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 rotates together with the output shaft; 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 holds at least a portion of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates, and which can press the input-side rotating plates and the output-side rotating plates; and a lifter plate fixed to the pressure 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 with respect to the axial direction of the output shaft, the pressure plate comprises: a base wall, and extending from the base wall in the first direction, and when rotating relative to the clutch center, the The device comprises a pressure-side cam portion 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, 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; a boss portion that is provided on the pressure-side cam portion in part and extends in the axial direction and fixes the lifter plate; and a recess that is formed on the pressure-side cam portion in part and recesses in the first direction more than the second direction side surface of the base wall, wherein at least a portion of the boss portion is located in the recess and is located toward the first direction more than the second direction side surface of the base wall, and is located toward the second direction more than the second direction side surface of the pressure-side cam portion that partitions the recess and is located opposite to the first direction side surface of the pressure-side cam portion.

[0008] According to the clutch device of the present invention, the pressure plate has a recess formed in the pressure-side cam portion, at least a portion of which is recessed in the first direction relative to the second direction surface of the base wall. Because the recess is formed in the pressure-side cam portion in this way, it is lighter than when the recess is not formed in the pressure-side cam portion. Furthermore, at least a portion of the end of the boss portion on the second direction side is located within the recess, and is located on the first direction side relative to the second direction surface of the base wall, and on the second direction side relative to the second direction surface of the pressure-side cam portion. Because a portion of the boss portion is located within the recess in this way, the rigidity around the recess can be increased. As a result, the clutch device has a pressure plate that is lighter while maintaining rigidity, thus achieving overall weight reduction of the clutch device. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a clutch device in which the weight of the pressure-side cam portion having a pressure-side assist cam surface and a pressure-side slipper cam surface in the pressure plate is reduced. [Brief explanation of the drawing]

[0010] [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 showing a part of a clutch device according to one embodiment. [Figure 3] Figure 3 is a plan view showing a part of a clutch device 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 clutch center according to one embodiment. [Figure 7] Figure 7 is a plan view of a clutch center according to one embodiment. [Figure 8]FIG. 8 is a perspective view of a clutch center and a nut according to an embodiment. [Figure 9] FIG. 9 is a perspective view of a pressure plate according to an embodiment. [Figure 10] FIG. 10 is a plan view of a pressure plate according to an embodiment. [Figure 11] FIG. 11 is a perspective view of a pressure plate according to an embodiment. [Figure 12] FIG. 12 is a plan view of a pressure plate according to an embodiment. [Figure 13] FIG. 13 is an enlarged cross-sectional view of a part of FIG. 1. [Figure 14A] FIG. 14A is a schematic diagram for explaining the operation of the center side assist cam surface and the pressure side assist cam surface. [Figure 14B] FIG. 14B is a schematic diagram for explaining the operation of the center side slipper cam surface and the pressure side slipper cam surface. [Figure 15] FIG. 15 is a side view showing a part of a pressure plate according to an embodiment. [Figure 16] FIG. 16 is an enlarged perspective view of a part of a pressure plate according to an embodiment. [Figure 17] FIG. 17 is an enlarged perspective view of a part of a pressure plate according to an embodiment.

Embodiments for Carrying out the Invention

[0011] Hereinafter, embodiments of the clutch device according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are not intended to limit the present invention in particular. In addition, members and parts having the same operation are denoted by the same reference numerals, and redundant descriptions are omitted or simplified as appropriate.

[0012] FIG. 1 is a cross-sectional view of a clutch device 10 according to the present embodiment. The clutch device 10 is provided in a vehicle such as a motorcycle, for example. The clutch device 10 is a device that transmits or blocks the rotational driving force of an input shaft (crankshaft) of a power source such as an engine of a motorcycle to an output shaft 15, for example. The clutch device 10 is a device for transmitting or blocking 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 an engine and a transmission.

[0013] In the following description, the direction in which the pressure plate 70 of the clutch device 10 approaches and separates from the clutch center 40 is defined as the left-right direction LR, the direction in which the pressure plate 70 approaches the clutch center 40 is defined as the right direction R, and the direction in which the pressure plate 70 separates from the clutch center 40 is defined as the left direction L. The right direction R is an example of the first direction, and the left direction L is an example of the second direction. In the drawings, the reference signs L and R denote the left and right directions, respectively. Also, the circumferential direction (i.e., the rotational direction) of the clutch center 40 and the pressure plate 70 is defined as the circumferential direction S, and the direction from one center-side cam portion 60 to the other center-side cam portion 60 (the direction from one pressure-side cam portion 90 to the other pressure-side cam portion 90) with respect to the circumferential direction S is defined as the first circumferential direction S1 (see FIG. 4), and the direction from the other center-side cam portion 60 to the one center-side cam portion 60 (the direction from the other pressure-side cam portion 90 to the one pressure-side cam portion 90) is defined as the second circumferential direction S2 (see FIG. 4). In the present embodiment, the axial direction of the output shaft 15 is the same as the left-right direction LR. Also, 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 to the center-side slipper cam surface 60S). In the present embodiment, the radial directions of the output shaft 15, the clutch housing 30, the clutch center 40, and the pressure plate 70 are the same direction. In the following description, unless otherwise specified, the "radial direction" refers to the radial direction of the output shaft 15. However, the above directions are merely defined for convenience of explanation and do not limit the installation mode of the clutch device 10 in any way, nor do they limit the present invention in any way.

[0014] As shown in Figure 1, the clutch device 10 comprises 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 lifter plate 100. In this embodiment, as shown in Figures 2 and 3, the clutch center 40, the pressure plate 70, and the lifter plate 100 are integrated. More specifically, the clutch center 40, the pressure plate 70, the multiple output side rotating plates 22 held by the pressure plate 70, the multiple input side rotating plates 20 arranged alternately with the output side rotating plates 22, the clutch spring 25 (see Figure 1), which will be described later, and the lifter plate 100 are integrated. These components are housed in the clutch housing 30 in an integrated state and fixed to the output shaft 15. When the clutch center 40, pressure plate 70, and lifter plate 100 are integrated, the pressure plate 70 is closest to the clutch center 40.

[0015] 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 bearing 15A. The output shaft 15 fixedly supports the clutch center 40 via a washer 15D and a nut 15N. That is, the output shaft 15 rotates integrally with the clutch center 40. As shown in Figures 2 and 3, the nut 15N is exposed to the outside through a through hole 100H formed in the lifter plate 100. As shown in Figure 3, when viewed in the axial direction (i.e., left-right direction LR) of the output shaft 15, the nut 15N does not overlap with the lifter plate 100. That is, the entire nut 15N overlaps with the through hole 100H. The other end of the output shaft 15 is connected to, for example, a transmission (not shown) of a motorcycle or automobile.

[0016] 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 to the right R from the edge of the bottom wall 31. The clutch housing 30 holds a plurality of input side rotating plates 20.

[0017] 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 (not shown). 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.

[0018] 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., left-right direction LR) of the clutch housing 30. The input-side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0019] 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 made of die-cast aluminum. 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.

[0020] 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.

[0021] 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. As shown in Figures 4 to 7, the clutch center 40 has a body 42 and a center-side flange 68 extending radially outward from the outer peripheral edge of the body 42. The body 42 protrudes to the left L of the center-side flange 68. The clutch center 40 does not hold the input-side rotating plate 20 and a plurality of output-side rotating plates 22 that are alternately arranged in the left-right direction L. The clutch center 40 is rotationally driven together with the output shaft 15.

[0022] As shown in Figure 4, the main body 42 includes an output shaft holding portion 50 located in the center of the main body 42, and a plurality of center-side cam portions 60 located radially outward from the output shaft holding portion 50.

[0023] As shown in Figure 4, the output shaft holder 50 is formed in a cylindrical shape. The output shaft holder 50 extends in the left-right direction LR. The left end face 50L of the output shaft holder 50 is located to the left L of the center-side cam portion 60. An insertion hole 51 is formed through the output shaft holder 50 into which the output shaft 15 is inserted and spline fitted. 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. As shown in Figure 8, a nut 15N (see also Figure 1) is placed on the right end face 50R (see also Figure 6) of the output shaft holder 50.

[0024] 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, which generates assist torque, 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, 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 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 4, the center-side cam portion 60 is formed on the main body 42. The left end face 60L of the center-side cam portion 60 is located to the left of the center-side flange 68. 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.

[0025] As shown in Figure 5, the center-side cam portion 60 has a center-side assist cam surface 60A (see also Figures 6 and 7) and a center-side slipper cam surface 60S (see also Figure 4). The center-side assist cam surface 60A is configured to generate a force (here, to the right R) 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 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 60X and the center slipper cam surface 60S of the other center cam portion 60Y are arranged facing each other in the circumferential direction S.

[0026] As shown in Figure 5, the clutch center 40 has a center-side cam hole 43H that penetrates a portion of the main body 42. The center-side cam hole 43H penetrates the main body 42 in the left-right direction (LR). The center-side cam hole 43H extends from the radially outer portion of the output shaft holding portion 50 to the center-side flange 68. The center-side cam hole 43H is formed between the center-side assist cam surface 60A and the center-side slipper cam surface 60S of adjacent center-side cam portions 60. The boss portion 84 (see Figure 1), which will be described later, of the pressure plate 70 is inserted into the center-side cam hole 43H. When viewed from the axial direction of the clutch center 40 (i.e., the axial direction of the output shaft 15), the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0027] As shown in Figures 6 and 7, the clutch center 40 is provided with a spring housing 54. The spring housing 54 is recessed from the right (R) to the left (L). The spring housing 54 is formed in the main body 42. More specifically, the spring housing 54 is formed in the center-side cam portion 60. The spring housing 54 houses the clutch spring 25 (see Figure 1). In this embodiment, the clutch center 40 is provided with three spring housings 54. The three spring housings 54 are arranged at equal intervals in the circumferential direction S of the clutch center 40. Note that the number of spring housings 54 is not limited to three. The spring housings 54 are located on the second circumferential direction S2 side of the center-side slipper cam surface 60S. The spring housings 54 are located on the first circumferential direction S1 side of the center-side assist cam surface 60A. The length of the center-side cam hole 43H in the circumferential direction S is longer than the length of the spring housing 54 in the circumferential direction S. As shown in Figure 1, the spring housing 54 has a bottom wall portion 54A that contacts the left end portion 25L of the clutch spring 25.

[0028] As shown in Figure 1, the clutch spring 25 is housed in the spring housing 54. The clutch spring 25 biases the pressure plate 70 toward the clutch center 40 (i.e., to the right R). The clutch spring 25 is, for example, a coil spring made by winding spring steel in a spiral shape.

[0029] As shown in Figures 4 and 5, the center flange 68 extends radially outward from the outer peripheral edge 42 of the main body. The center flange 68 is located radially outward from the center cam portion 60. The center flange 68, together with the pressure-side flange 98 (see Figure 9) of the pressure plate 70 (described later), clamps the input-side rotating plate 20 and the output-side rotating plate 22. The center flange 68 is provided so as to be able to press against the input-side rotating plate 20 and the output-side rotating plate 22. The center flange 68 is a member that applies pressing force to the input-side rotating plate 20 and the output-side rotating plate 22. The center flange 68 includes a pressing surface 68P capable of pressing against the input-side rotating plate 20 and the output-side rotating plate 22, and an inner diameter side surface 68Q located radially inward from the pressing surface 68P. The pressing surface 68P is provided so as to be able to contact the input-side rotating plate 20. The pressing surface 68P may be provided so as to be in contact with the output side rotating plate 22. The inner diameter side surface 68Q does not come into contact with the input side rotating plate 20 or the output side rotating plate 22. The inner diameter side surface 68Q faces at least a portion of the right end face of the mating tooth 77. The inner diameter side surface 68Q faces at least a portion of the right end face 77BPR of the projection 77BP. The inner diameter side surface 68Q normally faces at least a portion of the right end face 77AR of the mating tooth 77A. The pressing surface 68P is located to the left L of the inner diameter side surface 68Q.

[0030] As shown in Figure 1, the pressure plate 70 is housed in the clutch housing 30. The pressure plate 70 is located between the clutch housing 30 and the clutch center 40. The pressure plate 70 is located to the left L of the clutch center 40. The pressure plate 70 is provided so as to be able to move toward or away from the clutch center 40 and to be rotatable relative to it. The pressure plate 70 is configured 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. As shown in Figures 9 to 12, the pressure plate 70 has a body 72 and a pressure side flange 98 that is connected to the outer peripheral edge of the body 72 and extends radially outward. The body 72 protrudes to the right R of the pressure side flange 98. The pressure plate 70 holds all of the input side rotating plate 20 and the plurality of output side rotating plates 22 which are arranged alternately.

[0031] As shown in Figures 9 and 10, the main body 72 comprises an annular base wall 73, a fitting hole 80 provided in the center of the base wall 73, an outer peripheral wall 75 located radially outward from the base wall 73 and extending to the right R, and a plurality of pressure-side cam portions 90 connected to the base wall 73 and the outer peripheral wall 75.

[0032] As shown in Figures 9 and 11, the fitting hole 80 is formed in the center of the base wall 73. The fitting hole 80 penetrates the base wall 73 in the left-right direction (LR). The output shaft holding portion 50 (see Figure 4) of the clutch center 40 is inserted into the fitting hole 80. The fitting hole 80 is externally fitted onto the output shaft holding portion 50.

[0033] As shown in Figures 9 and 10, the outer peripheral wall 75 extends from the base wall 73 in the left-right direction LR (here, rightward R) and is formed in an annular shape when viewed from the axial direction of the output shaft 15 (i.e., left-right direction LR). A spline fitting portion 76 is provided on the outer peripheral surface 75A of the outer peripheral wall 75. The spline fitting portion 76 has a plurality of fitting teeth 77 that extend along the outer peripheral surface 75A of the outer peripheral wall 75 in the axial direction of the pressure plate 70 (i.e., left-right direction LR), and a plurality of spline grooves 78 formed between adjacent fitting teeth 77 and extending in the axial direction of the pressure plate 70. The fitting teeth 77 hold all of the plurality of output-side rotating plates 22. The plurality of fitting teeth 77 are arranged at equal intervals in the circumferential direction S. The fitting teeth 77 protrude radially outward from the outer peripheral surface 75A of the outer peripheral wall 75. The plurality of spline grooves 78 are arranged at equal intervals in the circumferential direction S. Multiple spline grooves 78 are formed to have the same shape.

[0034] The output-side rotating plate 22 is held in the spline-fitting portion 76 of the pressure plate 70. All of the multiple output-side rotating plates 22 are held in the fitting teeth 77 and spline grooves 78 of the pressure plate 70 by spline fitting. The output-side rotating plate 22 is provided so as to be displaceable along the axial direction (i.e., left-right direction LR) of the pressure plate 70. The output-side rotating plate 22 is provided so as to be rotatable integrally with the pressure plate 70.

[0035] As shown in Figure 9, the mating teeth 77 include a plurality of normal mating teeth 77A and a plurality of extended mating teeth 77B. The right end face 77AR of the normal mating teeth 77A is formed flush with the right end face 75R of the outer peripheral wall 75. The extended mating teeth 77B have projections 77BP that extend to the right R beyond the right end face 75R of the outer peripheral wall 75. The projections 77BP are located radially outward of the pressure-side cam portion 90. The projections 77BP are located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S, which will be described later, with respect to the circumferential direction S. The projections 77BP are located radially outward of the boss portion 84, which will be described later. The projections 77BP are located between the first circumferential direction S1 end of the boss portion 84 and the second circumferential direction S2 end of the boss portion 84 with respect to the circumferential direction S. The extended mating teeth 77B are arranged at equal intervals in the circumferential direction S. In this embodiment, the mating teeth 77 include three extended mating teeth 77B, but the number of extended mating teeth 77B is not limited to three.

[0036] Figure 13 is an enlarged cross-sectional view of a part of the clutch device 10, showing the state in which the pressure plate 70 is closest to the clutch center 40 (i.e., the clutch is fully engaged). As shown in Figure 13, in the state in which the pressure plate 70 is closest to the clutch center 40, the axial distance (i.e., left-right direction LR) LX between at least a part of the mating teeth 77 (here, the extended mating teeth 77B) and the inner diameter side surface 68Q of the center-side flange 68 is less than or equal to the axial length LY of the input-side rotating plate 20R, which is located furthest to the right R of the input-side rotating plate 20 and the output-side rotating plate 22. Here, the axial length LY of the input-side rotating plate 20R is the axial length of the portion of the input-side rotating plate 20 that can contact the output-side rotating plate 22. The input-side rotating plate 20R is an example of a specific rotating plate. When the pressure plate 70 is closest to the clutch center 40, the axial distance LX between the right end face 77BPR of the projection 77BP and the inner diameter side surface 68Q is less than or equal to the axial length LY of the input side rotating plate 20R. When the pressure plate 70 is closest to the clutch center 40, the axial distance LX between the right end face 77BPR of the projection 77BP and the inner diameter side surface 68Q is, for example, less than or equal to three-quarters (preferably less than or equal to half) of the axial length LY of the input side rotating plate 20R. When the pressure plate 70 is closest to the clutch center 40, the axial distance LX between the right end face 77BPR of the projection 77BP and the inner diameter side surface 68Q is, for example, more than or equal to one-quarter (preferably more than half) of the axial length LY of the input side rotating plate 20R. Furthermore, when the pressure plate 70 is closest to the clutch center 40, the axial distance between the right end face 75R of the outer peripheral wall 75 and the pressing surface 68P of the center-side flange 68 may be longer than, shorter than, or equal to the axial length LY of the input-side rotating plate 20R.

[0037] 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 extends to the right R from the base wall 73. The pressure-side cam portion 90 is formed to protrude to the right R from the pressure-side flange 98. As shown in Figure 10, 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.

[0038] As shown in Figure 10, the pressure-side cam portion 90 is located radially outward of the fitting hole 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also Figures 11 and 12) 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 90X and the pressure-side slipper cam surface 90S of the other pressure-side cam section 90Y are arranged opposite each other in the circumferential direction S. As shown in Figure 15, the axial length (i.e., left-right direction LR) 90AL of the pressure-side assist cam surface 90A is longer than the axial length (i.e., left-right direction LR) 90SL of the pressure-side slipper cam surface 90S. The right end of the pressure-side slipper cam surface 90S is located to the left L of the right end of the pressure-side assist cam surface 90A.

[0039] 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 first rotational force in the circumferential direction S1 is applied to the pressure plate 70, as shown in Figure 14A. As a result, the operation of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A generates a force directed to the right R on the pressure plate 70. This increases the contact force between the input-side rotating plate 20 and the output-side rotating plate 22.

[0040] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30, resulting in back torque, a first circumferential rotational force S1 is applied to the clutch center 40, as shown in Figure 14B. 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 to the left L, 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.

[0041] As shown in Figures 10 and 12, the pressure plate 70 has a pressure-side cam hole 73H that penetrates a portion of the base wall 73. The pressure-side cam hole 73H penetrates the base wall 73 in the left-right direction (LR). The pressure-side cam hole 73H is located radially outward from the fitting hole 80. The pressure-side cam hole 73H extends from the side of the fitting hole 80 to the outer peripheral wall 75. The pressure-side cam hole 73H is formed through between adjacent pressure-side cam portions 90. The pressure-side cam hole 73H 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. The pressure-side cam hole 73H has, with respect to the circumferential direction S, a first portion 73H1 located on the pressure-side assist cam surface 90A side and a second portion 73H2 located on the pressure-side slipper cam surface 90S side. The radial length L1 of the first portion 73H1 is longer than the radial length L2 of the second portion 73H2. The radially inner end of the first portion 73H1 is located radially inward than the radially inner end of the second portion 73H2. The radially inner end of the first portion 73H1 is located radially inward than the radially inner end of the pressure-side assist cam surface 90A. When viewed from the axial direction (i.e., left-right direction LR) of the output shaft 15, a gap SP is formed in the radial direction between the radially inner end of the first portion 73H1 and the radially inner end of the first circumferential direction S1 side (i.e., the pressure-side assist cam surface 90A side) of the pressure-side cam portion 90, with respect to the radial direction, and the gap SP penetrates the base wall 73 in the left-right direction LR. Clutch oil flowing outside the pressure plate 70 flows into the interior of the pressure plate 70 through this gap SP. A portion of the clutch oil that flows into the interior of the pressure plate 70 is supplied to the pressure-side assist cam surface 90A. With respect to the circumferential direction S, a stepped portion 74 is provided at the boundary between the first portion 73H1 and the second portion 73H2. When viewed from the axial direction (i.e., left-right direction LR) of the pressure plate 70, the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 73H (in this case, the first portion 73H1) overlap.

[0042] As shown in Figures 9 and 10, the pressure plate 70 has a plurality of (three in this embodiment) boss portions 84. The plurality of boss portions 84 are arranged at equal intervals in the circumferential direction S. The boss portions 84 are formed in a cylindrical shape. The boss portions 84 are located radially outward from the fitting hole 80. The boss portions 84 extend in the left-right direction LR. A part of the boss portion 84 extends to the right R from the base wall 73. At least a part of the boss portion 84 is provided on the pressure-side cam portion 90. The boss portion 84 may be provided at a position separated from the pressure-side cam portion 90. The boss portion 84 is provided integrally with the pressure-side cam portion 90. The boss portion 84 extends to the right R from the right surface 90R of the pressure-side cam portion 90. The boss portion 84 is located between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S with respect to the circumferential direction S. As shown in Figure 1, the boss portion 84 is inserted into the center-side cam hole 43H. The boss portion 84 has a threaded hole 84H into which a bolt 28 is inserted. The threaded hole 84H extends in the left-right direction LR. The boss portion 84 fixes the lifter plate 100 via the bolt 28.

[0043] As shown in Figures 9 and 10, the pressure plate 70 is provided with a projection 95 on the pressure-side cam portion 90. The projection 95 is located at the end of the pressure-side cam portion 90 on the first circumferential direction S1 side. Note that the first circumferential direction S1 side edge of the projection 95 and the first circumferential direction S1 side edge of the pressure-side cam portion 90 do not have to coincide. That is, when viewed in the axial direction of the output shaft 15 (i.e., left-right direction LR), a gap may be formed between the first circumferential direction S1 side edge of the projection 95 and the first circumferential direction S1 side edge of the pressure-side cam portion 90 with respect to the circumferential direction S. It is desirable that the length of this gap in the circumferential direction S is shorter than the length of the projection 95 in the circumferential direction S. The projection 95 extends from the right surface 90R of the pressure-side cam portion 90 toward the right R. At least a portion of the projection 95 extends radially. As shown in Figure 16, the protrusion 95 has a first protrusion 96 and a second protrusion 97 that is continuous with the first protrusion 96.

[0044] As shown in Figure 16, the first projection 96 extends radially along the first circumferential S1 end of the pressure-side cam portion 90. The first projection 96 extends radially from the radially inner end of the pressure-side cam portion 90. The first projection 96 is continuous with the outer peripheral wall 75. The radially outer end of the first projection 96 is continuous with the outer peripheral wall 75. The right face 96R of the first projection 96 is flush with the right end face 75R of the outer peripheral wall 75. The first projection 96 has a first portion 96A with a first length in the circumferential direction S, and a second portion 96B which is located radially outward from the first portion 96A and has a second length in the circumferential direction S that is longer than the first length. When viewed radially, at least a portion of the first projection 96 overlaps with the mating teeth 77. When viewed in the axial direction (i.e., left-right direction LR) of the output shaft 15, the first protrusion 96 coincides with the pressure-side assist cam surface 90A.

[0045] As shown in Figure 16, the second projection 97 extends in the circumferential direction S. The second projection 97 extends in the circumferential direction S along the radially inward end of the pressure-side cam portion 90. The second projection 97 is continuous with the boss portion 84. The second circumferential direction S2 end of the second projection 97 is continuous with the boss portion 84. The right surface 97R of the second projection 97 is flush with the right surface 96R of the first projection 96. That is, the right surface 97R of the second projection 97 is flush with the right end surface 75R of the outer peripheral wall 75. Note that the projection 95 does not necessarily have to have the second projection 97.

[0046] As shown in Figures 11 and 12, the pressure plate 70 includes a recess 99 formed in at least part of the pressure-side cam portion 90. Here, the recess 99 is formed in the base wall 73 and the pressure-side cam portion 90. The recess 99 is recessed to the right R from the left surface 73L of the base wall 73. Here, the recess 99 is recessed to the right R from the left surface 73L of the base wall 73. The recess 99 is located between adjacent pressure-side cam holes 73H with respect to the circumferential direction S. The recess 99 is demarcated by the left surface 90L of the pressure-side cam portion 90, which is located opposite the right surface 90R (see Figure 9) of the pressure-side cam portion 90, and by a side surface 91 extending in the axial direction (i.e., left-right direction LR). The side surface 91 has an inner side surface 91I, an outer side surface 91O located radially outward from the inner side surface 91I, an assist side surface 91A located on the pressure-side assist cam surface 90A side, and a slipper side surface 91S located on the pressure-side slipper cam surface 90S side. The inner side surface 91I is located radially inward from a portion of the boss portion 84. The outer side surface 91O is located radially outward from the boss portion 84. The assist side surface 91A is located on the pressure-side assist cam surface 90A side with respect to the circumferential direction S than the pressure-side slipper cam surface 90S. The assist side surface 91A connects the first circumferential end of the inner side surface 91I on the circumferential direction S1 side to the first circumferential end of the outer side surface 91O on the circumferential direction S1 side. The slipper side surface 91S is located on the pressure-side slipper cam surface 90S side with respect to the circumferential direction S than the pressure-side assist cam surface 90A. The slipper side surface 91S connects the end of the inner surface surface 91I on the second circumferential direction S2 side to the end of the outer surface surface 91O on the second circumferential direction S2 side. The slipper side surface 91S is inclined so that it is positioned more towards the second circumferential direction S2 side as it moves to the left L. The slipper side surface 91S is parallel to the pressure-side slipper cam surface 90S.

[0047] As shown in Figure 17, at least a portion of the left end 84L of the boss portion 84 is located within the recess 99. The left end 84L of the boss portion 84 is located to the right R of the left surface 73L of the base wall 73. The left end 84L of the boss portion 84 is located to the right R of the center LR in the left-right direction of the recess 99. The left end 84L of the boss portion 84 is located to the left L of the left surface 90L of the pressure-side cam portion 90. The left end 84L of the boss portion 84 is continuous with the side surface 91. The left end 84L of the boss portion 84 is continuous with the inner surface 91I. The left end 84L of the boss portion 84 is continuous with at least a portion of the inner surface 91I with respect to the circumferential direction S, specifically the portion on the pressure-side assist cam surface 90A side (first circumferential direction S1 side) of the inner surface 91I that is on the center of the circumferential direction S of the inner surface 91I. The left end 84L of the boss portion 84 is continuous with the assist side surface 91A. The left end portion 84L of the boss portion 84 is not continuous with the outer surface 91O. The left end portion 84L of the boss portion 84 is not continuous with the slipper surface 91S. As shown in Figure 12, a portion of the boss portion 84 is located radially inward from the slipper surface 91S. The center 84C of the boss portion 84 is located radially inward from the slipper surface 91S.

[0048] As shown in Figures 9 and 10, the pressure-side flange 98 extends radially outward from the outer peripheral edge 72 of the main body. The pressure-side flange 98 is located radially outward from the outer peripheral wall 75. 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 a pressing force to the input-side rotating plate 20 and the output-side rotating plate 22.

[0049] As shown in Figure 1, the lifter plate 100 is fixed to the boss portion 84 via bolts 28. The lifter plate 100 is a component for displacing the pressure plate 70 in the left-right direction (LR). The lifter plate 100 is located to the right (R) of the clutch center 40. The lifter plate 100 supports the clutch spring 25. The right end 25R of the clutch spring 25 contacts the lifter plate 100. The lifter plate 100 is fixed to the pressure plate 70. The lifter plate 100 has an insertion hole 104H into which the bolts 28 that fix the lifter plate 100 to the pressure plate 70 are inserted. The lifter plate 100 is fixed to the boss portion 84 of the pressure plate 70 by the bolts 28. A through hole 100H is formed in the center of the lifter plate 100. The lifter plate 100 rotates integrally with the pressure plate 70. The lifter plate 100 moves in the left-right direction (L / R) relative to the clutch center 40 and rotates relative to the clutch center 40. The lifter plate 100 is operated by a clutch release mechanism (not shown). When the lifter plate 100 moves to the left (L), the pressure plate 70 also moves to the left (L). Here, the clutch release mechanism is a mechanical device that operates in a vehicle such as a motorcycle equipped with a clutch device 10 by the operation of the driver's clutch lever (not shown). The clutch release mechanism may also be electrically operated by a servo motor or the like.

[0050] Next, the assembly of the clutch device 10 will be described. First, with multiple input-side rotating plates 20 and multiple output-side rotating plates 22 arranged alternately, the output-side rotating plates 22 are attached to the mating teeth 77 of the pressure plate 70. Then, the clutch center 40 is attached to the pressure plate 70. After that, the clutch spring 25 is housed in the spring housing portion 54 of the clutch center 40, and with the lifter plate 100 in contact with the tip of the boss portion 84 of the pressure plate 70 (right end in Figure 1), the lifter plate 100 is fixed to the boss portion 84 with bolts 28. As a result, with the pressure plate 70 in its closest position to the clutch center 40, the clutch center 40, the pressure plate 70, the output-side rotating plates 22, the input-side rotating plates 20, the clutch spring 25, and the lifter plate 100 are integrated into one unit. Then, by engaging the input-side rotating plate 20 with the notch 30C of the clutch housing 30, the integrated clutch center 40, pressure plate 70, output-side rotating plate 22, input-side rotating plate 20, clutch spring 25, and lifter plate 100 are attached to the clutch housing 30. Finally, by inserting a washer 15D and a nut 15N through the through hole 100H formed in the lifter plate 100 and fixing the clutch center 40 to the output shaft 15, the integrated clutch center 40, pressure plate 70, output-side rotating plate 22, input-side rotating plate 20, clutch spring 25, and lifter plate 100 are attached to the output shaft 15. The washer 15D and nut 15N are fixed to the output shaft 15.

[0051] As described above, in the clutch device 10 of this embodiment, the pressure plate 70 has a recess 99 formed in the pressure-side cam portion 90, at least a portion of which is recessed to the right R of the left surface 73L of the base wall 73. In this way, because the recess 99 is formed in the pressure-side cam portion 90, it is lighter than when the recess 99 is not formed in the pressure-side cam portion 90. Furthermore, at least a portion of the left end portion 84L of the boss portion 84 is located within the recess 99, and is located to the right R of the left surface 73L of the base wall 73, and is located to the left L of the left surface 90L of the pressure-side cam portion 90. In this way, because a portion of the boss portion 84 is located within the recess 99, the rigidity around the recess 99 can be increased. As described above, the clutch device 10 has a pressure plate 70 that is lighter while maintaining rigidity, thus achieving overall weight reduction of the clutch device 10.

[0052] In the clutch device 10 of this embodiment, the left end portion 84L of the boss portion 84 is continuous with the side surface 91 that demarcates the recess 99 of the pressure-side cam portion 90 and extends in the left-right direction LR. According to the above embodiment, since a part of the boss portion 84 is continuous with the side surface 91 of the pressure-side cam portion 90, the rigidity around the recess 99 can be further increased.

[0053] In the clutch device 10 of this embodiment, the left end portion 84L of the boss portion 84 is continuous with the inner surface 91I. According to the above embodiment, since a part of the boss portion 84 is continuous with the inner surface 91I of the pressure-side cam portion 90, the rigidity around the recess 99 can be further increased.

[0054] In the clutch device 10 of this embodiment, the left end portion 84L of the boss portion 84 is continuous with at least a portion of the inner surface 91I that is on the side of the pressure-side assist cam surface 90A with respect to the circumferential direction S. According to the above embodiment, by having a portion of the boss portion 84 continuous with at least a portion of the inner surface 91I that is on the side of the pressure-side assist cam surface 90A that is on the side of the circumferential direction center of the inner surface 91I, the rigidity of the recess 99 around the pressure-side assist cam surface 90A can be increased.

[0055] In the clutch device 10 of this embodiment, the left end portion 84L of the boss portion 84 is continuous with the assist side surface 91A. According to the above embodiment, by having a part of the boss portion 84 continuous with the assist side surface 91A, the rigidity of the recess 99 around the pressure-side assist cam surface 90A can be increased.

[0056] 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.

[0057] In the embodiment described above, the first projection 96 is continuous with the outer peripheral wall 75, but it does not have to be continuous with the outer peripheral wall 75. That is, the radially outer end of the first projection 96 does not have to be continuous with the outer peripheral wall 75. Also, the second projection 97 is continuous with the boss portion 84, but it does not have to be continuous with the boss portion 84. That is, the second circumferential end of the second projection 97 on the S2 side does not have to be continuous with the boss portion 84.

[0058] In the embodiment described above, the left end portion 84L of the boss portion 84 is continuous with the inner surface 91I, but it may also be continuous with the inner surface 91I and the outer surface 91O, or it may not be continuous with the inner surface 91I but be continuous with the outer surface 91O. Furthermore, the left end portion 84L of the boss portion 84 does not have to be continuous with the side surface 91.

[0059] In the embodiment described above, the input-side rotating plate 20R (input-side rotating plate 20) is located furthest to the right R of the input-side rotating plate 20 and the output-side rotating plate 22, but it may also be the output-side rotating plate 22. In this case, the axial length LY of the output-side rotating plate 22 is the axial length of the portion of the output-side rotating plate 22 that can contact the input-side rotating plate 20.

[0060] In the embodiment described above, all of the protrusions 77BP were located radially outward of the boss portion 84, but some of the multiple protrusions 77BP may be located radially outward of the boss portion 84.

[0061] In the embodiment described above, the projection 95 was located at the first circumferential S1 end of the pressure-side cam portion 90, but is not limited thereto. For example, the projection 95 may be located at the second circumferential S2 end of the pressure-side cam portion 90. Alternatively, the projection 95 may be provided at both the first circumferential S1 end and the second circumferential S2 end of the pressure-side cam portion 90. If the projection 95 is located at the second circumferential S2 end of the pressure-side cam portion 90, the first projection 96 may extend radially along the second circumferential S2 end of the pressure-side cam portion 90, and the projection 95 may include a second projection 97 that is continuous with the first projection 96 and extends circumferentially S along the radially inner end of the pressure-side cam portion 90.

[0062] In the embodiment described above, the pressure plate 70 holds all of the output-side rotating plates 22, but this is not limited to this configuration. For example, the pressure plate 70 may be configured to hold some of the multiple output-side rotating plates 22, and the clutch center 40 may be configured to hold other parts of the multiple output-side rotating plates 22. [Explanation of Symbols]

[0063] 10. Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 30 Clutch Housing 40 Clutch Center 70 Pressure Plates 73 Base Wall 73L Left side (side facing the second direction) 75 Outer wall 77 interlocking teeth 78 spline grooves 84 Boss Section 84L Left end (end on the second direction side) 90 Pressure-side cam section 90A Pressure-side assist cam surface 90L Left side (side facing the second direction) 90R Right side (side facing the first direction) 90S Pressure side slipper cam surface 91 Side view 91O outer surface 91I Inner surface 91A Assist side 99 recess 100 Lifter Plate

Claims

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 is rotated together with the output shaft, A pressure plate is provided that is movable toward or away from the clutch center and rotatable relative to it, and holds at least a portion of a plurality of output-side rotating plates arranged alternately with the input-side rotating plate, and is capable of pressing the input-side rotating plate and the output-side rotating plate. With respect to the axial direction of the output shaft, 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 device comprises a lifter plate located on the first direction side of the clutch center and fixed to the pressure plate, The aforementioned pressure plate is Base wall and, A pressure-side cam portion having a pressure-side assist cam surface that extends from the base wall in the first direction and, when rotated relative to the clutch center, generates a force in the direction from the pressure plate toward the clutch center in order to increase the pressing force between the input-side rotating plate and the output-side rotating plate, 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, At least a portion of the boss portion is provided on the pressure-side cam portion, extends in the axial direction, and fixes the lifter plate, It comprises a recess formed at least in part on the pressure-side cam portion, which is recessed in the first direction more than the second direction side surface of the base wall, A clutch device wherein at least a portion of the boss portion on the second direction side is located within the recess and is located on the first direction side of the base wall on the second direction side and is located on the second direction side of the pressure-side cam portion that partitions the recess and is located on the second direction side of the pressure-side cam portion opposite to the first direction side of the pressure-side cam portion.

2. The clutch device according to claim 1, wherein the end of the boss portion on the second direction side is continuous with the side of the pressure-side cam portion that demarcates the recess and extends in the axial direction.

3. The aforementioned side surface includes an outer surface located radially outward from the boss portion and an inner surface located radially inward from a portion of the boss portion. The clutch device according to claim 2, wherein the end of the boss portion on the second direction side is continuous with the inner surface.

4. The clutch device according to claim 3, wherein the end of the boss portion on the second direction side is continuous with at least a portion of the inner surface that is on the pressure-side assist cam surface side of the circumferential direction, compared to the circumferential center of the inner surface.

5. The aforementioned side surface includes an outer surface located radially outward from the boss portion, an inner surface located radially inward from a part of the boss portion, and an assist side surface connecting the outer surface and the inner surface and located circumferentially on the pressure-side assist cam surface side than the pressure-side slipper cam surface. The clutch device according to claim 2, wherein the end of the boss portion on the second direction side is continuous with the assist side surface.

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