Clutch device

Abstract

A centrifugal clutch mechanism 120 comprises a holding member 140 movably holding a weight member 130 between a radially inner position MI and a radially outer position MO, wherein the weight member 130 has a first surface 131, a first contact surface 132A that comes into contact with a first partition wall 146W1 when located at the radially outer position MO, a second contact surface 132B that comes into contact with a second partition wall 146W2 when located at the radially outer position MO. When viewed from the axial direction of an output shaft 15, a first straight line L1 passing through one end in a circumferential direction S of the first contact surface 132A and the other end in the circumferential direction S thereof, and a second straight line L2 passing through one end in the circumferential direction S of the second contact surface 132B and the other end in the circumferential direction S thereof intersect each other at a position radially outward of the first surface 131.

Description

Clutch device

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

[0002] A saddle-type vehicle such as a motorcycle includes a clutch device that can transmit or cut off the rotational driving force of a power source such as an engine to a drive wheel. For example, in Patent Document 1, an input member (hereinafter referred to as an input shaft) connected to the engine side, an output member (hereinafter referred to as an output shaft) connected to the drive wheel side, a clutch member (hereinafter referred to as a clutch center) connected to the output shaft, and a pressure member (hereinafter referred to as a pressure plate) that can approach and separate from the clutch center are disclosed.

[0003] Further, the clutch device of Patent Document 1 includes a centrifugal clutch mechanism including a weight member that moves in the radial direction and a holding member that houses the weight member. The weight member moves from a position on the inner side in the radial direction to a position on the outer side in the radial direction by the centrifugal force accompanying the rotation of the clutch housing. As the weight member moves from a position on the inner side in the radial direction to a position on the outer side in the radial direction, a semi-clutch state is formed in which the driving-side clutch plate (hereinafter referred to as the input-side rotating plate) and the driven-side clutch plate (hereinafter referred to as the output-side rotating plate) come into contact, and the driving force of the engine is configured to be transmitted to the output shaft.

[0004] Japanese Patent No. 7480281

[0005] By the way, when the weight member housed in the holding member moves from a position on the inner side in the radial direction to a position on the outer side in the radial direction, the weight member is configured to abut against the holding member. Also, a slight gap is provided between the weight member and the holding member in the circumferential direction so that the weight member housed in the holding member can move smoothly in the radial direction. Therefore, depending on the way the weight member in the position on the outer side in the radial direction contacts the holding member, there is a risk that the weight member vibrates in the circumferential direction and the riding comfort deteriorates.

[0006] The present invention has been made in view of such a point, and an object thereof is to provide a clutch device in which a decrease in riding comfort is suppressed.

[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, comprising: a clutch center housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational drive of the input shaft, and which rotates together with the output shaft; a pressure plate provided so as to be able to approach and separate from the clutch center, 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 the clutch housing The centrifugal clutch machine comprises a weight member configured to move from a radially inner position to a radially outer position due to the centrifugal force accompanying the rotation of the shaft, and a centrifugal clutch mechanism which, when the weight member is in the radially inner position, releases the contact force between the input side rotating plate and the output side rotating plate, thereby blocking the transmission of the rotational driving force of the input shaft to the output shaft, and increases the rotational driving force transmitted from the input shaft to the output shaft as the weight member moves from the radially inner position to the radially outer position, and the centrifugal clutch machine The structure includes a holding member that holds the weight member so as to be movable between an inner position in the radial direction and an outer position in the radial direction, the holding member includes a housing portion for housing the weight member, the weight member has an outer surface in the radial direction and a first surface that extends in a direction intersecting a center line passing through the center of the weight member and the center of the holding member when viewed from the axial direction of the output shaft, and a portion located on one side in the circumferential direction from the first surface, inclined with respect to the center line, and when in the outer position in the radial direction, the housing portion of the holding member is separated The retaining member has a first contact surface that contacts a first partition wall that defines a section, and a second contact surface that is located on the other side in the circumferential direction from the first surface, is inclined with respect to the center line, and when it is located on the radially outer side, contacts a second partition wall that defines the housing section of the retaining member, and when viewed from the axial direction, a first straight line passing through one end of the first contact surface in the circumferential direction and the other end of the first contact surface, and a second straight line passing through one end of the second contact surface in the circumferential direction and the other end of the second contact surface, intersect at a position radially outer from the first surface.

[0008] According to the clutch device of the present invention, the weight member has a first surface, a first contact surface that contacts a first partition wall that defines the housing portion of the holding member, and a second contact surface that contacts a second partition wall that defines the housing portion. A first straight line passing through one circumferential end and the other circumferential end of the first contact surface, and a second straight line passing through one circumferential end and the other circumferential end of the second contact surface, intersect at a position radially outward from the first surface. In the above embodiment, since the first contact surface and the second contact surface are inclined with respect to a center line passing through the center of the weight member and the center of the holding member when viewed from the axial direction of the output shaft, when the weight member moves to a radially outward position and the first contact surface comes into contact with the first partition wall and the second contact surface comes into contact with the second partition wall, the circumferential movement of the weight member can be suppressed. This suppresses a decrease in ride comfort. In addition, the portion of the holding member that receives the pressing force from the weight member is stabilized, so the strength of the holding member can be ensured.

[0009] According to the present invention, it is possible to provide a clutch device that suppresses a decrease in ride comfort.

[0010] Figure 1 is a cross-sectional view of the clutch device according to this embodiment. Figure 2 is a perspective view of the clutch center according to this embodiment. Figure 3 is a perspective view of the clutch center according to this embodiment. Figure 4 is a perspective view of the pressure plate according to this embodiment. Figure 5 is a perspective view of the pressure plate according to this embodiment. Figure 6A is a schematic diagram illustrating the operation of the center-side assist cam surface and the pressure-side assist cam surface. Figure 6B is a schematic diagram illustrating the operation of the center-side slipper cam surface and the pressure-side slipper cam surface. Figure 6C is an enlarged cross-sectional view of a part of the clutch device according to this embodiment. Figure 7 is a perspective view showing the centrifugal clutch mechanism according to this embodiment, showing the weight member positioned radially inward. Figure 8 is a plan view showing the centrifugal clutch mechanism according to this embodiment, showing the weight member positioned radially inward. Figure 9 is a plan view showing a part of the centrifugal clutch mechanism according to this embodiment, showing the weight member positioned radially inward. Figure 10A is a plan view showing a part of the centrifugal clutch mechanism according to this embodiment, and is an enlarged plan view showing the state in which the weight member is located radially inward. Figure 10B is an enlarged plan view of a part of Figure 10A. Figure 11 is a plan view showing a part of the centrifugal clutch mechanism according to this embodiment, and is an enlarged plan view showing the state in which the weight member is located radially outward. Figure 12 is a plan view showing the retaining member according to this embodiment. Figure 13 is a perspective view showing the retaining member according to this embodiment. Figure 14 is an enlarged plan view showing a part of the retaining member according to this embodiment. Figure 15 is an enlarged perspective view showing a part of the retaining member according to this embodiment. Figure 16A is an enlarged plan view showing a part of the retaining member according to this embodiment. Figure 16B is an enlarged plan view of a part of Figure 16A. Figure 17 is a plan view showing the weight member and spring according to this embodiment. Figure 18 is a plan view showing the weight member and spring according to this embodiment. Figure 19 is a perspective view showing the weight member and spring according to this embodiment. Figure 20 is a perspective view showing the weight member and spring according to this embodiment. Figure 21A is a plan view showing a pressure-welded member according to this embodiment. Figure 21B is a cross-sectional view along line A-A in Figure 21A.Figure 22 is a perspective view showing a pressure-contacting member according to this embodiment. Figure 23 is a perspective view showing a part of the centrifugal clutch mechanism according to this embodiment. Figure 24 is a plan view showing a part of the centrifugal clutch mechanism according to this embodiment, and is an enlarged plan view showing the state in which the weight member is located radially inward. Figure 25 is a plan view showing the pressure-contacting member and guide member according to this embodiment. Figure 26 is a side view showing the pressure-contacting member and guide member according to this embodiment. Figure 27 is a cross-sectional view of the clutch device according to this embodiment. Figure 28 is an enlarged plan view showing a part of a retaining member according to a modified example. Figure 29 is an enlarged plan view showing a part of a retaining member and weight member according to a modified example. Figure 30 is a plan view showing a weight member and spring according to a modified example. Figure 31 is an enlarged cross-sectional view showing a part of the clutch device according to a modified example. Figure 32 is an enlarged plan view showing a part of a pressure-contacting member according to a modified example.

[0011] Hereinafter, embodiments of the clutch device according to the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for members and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0012] Figure 1 is a cross-sectional view of the clutch device 10 according to this embodiment. The clutch device 10 is installed in a saddle-type vehicle such as a motorcycle. The clutch device 10 is a device that transmits or interrupts the rotational driving force of the input shaft (crankshaft) of the engine, which is the power source of the motorcycle, to the output shaft 15. The clutch device 10 is a device for transmitting or interrupting the rotational driving force of the input shaft to the drive wheel (rear wheel) via the output shaft 15. The clutch device 10 is positioned between the engine and the transmission.

[0013] In the following description, the directions in which the pressure plate 70 of the clutch device 10 approaches and moves away from the clutch center 40 are denoted as the left-right direction LR, the direction in which the pressure plate 70 approaches the clutch center 40 is denoted as the left direction L, and the direction in which the pressure plate 70 moves away from the clutch center 40 is denoted as the right direction R. The right direction R is an example of the first direction, and the left direction L is an example of the second direction. The symbols L and R in the drawings mean left and right, respectively. Furthermore, the circumferential direction (i.e., rotational direction) of the clutch center 40 and the pressure plate 70 is defined as the circumferential direction S. With respect to the circumferential direction S, the direction from one center-side cam portion 60 toward the other center-side cam portion 60 (the direction from one pressure-side cam portion 90 toward the other pressure-side cam portion 90) is defined as the first circumferential direction S1 (see Figure 2), and the direction from the other center-side cam portion 60 toward the one center-side cam portion 60 (the direction from the other pressure-side cam portion 90 toward the one pressure-side cam portion 90) is defined as the second circumferential direction S2 (see Figure 2). In this 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 toward the center-side slipper cam surface 60S). However, the directions described above are merely defined for the sake of explanation and do not limit the installation configuration 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 includes an output shaft 15, a plurality of input-side rotating plates 20, a plurality of output-side rotating plates 22, a clutch housing 30, a clutch center 40, a pressure plate 70, a stopper plate 100, a centrifugal clutch mechanism 120, and an auxiliary clutch plate 180.

[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 needle bearing 28A. The output shaft 15 fixedly supports the clutch center 40 via a nut 28B. 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 motorcycle transmission (not shown).

[0016] As shown in Figure 1, the output shaft 15 has a main body portion 15A that extends in the left-right direction L and R. The main body portion 15A has an oil passage 15H through which clutch oil flows. The oil passage 15H is formed between the sleeve 16C, which is fitted onto the push rod 16A (described later), and the main body portion 15A. The clutch oil flows inside the output shaft 15, that is, inside the oil passage 15H of the main body portion 15A.

[0017] As shown in Figure 1, the oil passage 15H of the output shaft 15 is provided with a push rod 16A and a push member 16B adjacent to the push rod 16A. The push rod 16A and the push member 16B are slidably mounted within the sleeve 16C. One end of the push rod 16A (the left end in the figure) is connected to the clutch operating lever (not shown) of a motorcycle, and operation of the clutch operating lever causes it to slide within the sleeve 16C and press the push member 16B to the right R. A part of the push member 16B protrudes outward from the output shaft 15 (to the right R in this case) and is connected to a release bearing 18 provided on the pressure plate 70. The sleeve 16C and the push member 16B are formed to be narrower than the inner diameter of the main body 15A, ensuring the flow of clutch oil within the oil passage 15H. The push rod 16A may also be configured to slide electrically by a servo motor or the like.

[0018] The clutch housing 30 is formed from aluminum die-cast. 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.

[0019] As shown in Figure 1, an input gear 35 is provided on the bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by rivets 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates due to the rotational drive of the engine's input shaft. The input gear 35 rotates independently of the output shaft 15 and integrally with the clutch housing 30.

[0020] The input-side rotating plate 20 is rotationally driven by the rotational drive of the input shaft. As shown in Figure 1, the input-side rotating plate 20 is held on the inner circumferential surface of the side wall 33 of the clutch housing 30. The input-side rotating plate 20 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. The input-side rotating plate 20 is provided so as to be displaceable along the axial direction (i.e., 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.

[0021] The input-side rotating plate 20 is a component that is pressed against the output-side rotating plate 22. The input-side rotating plate 20 is formed in an annular shape. The input-side rotating plate 20 is molded from aluminum die-cast. A friction material (not shown) consisting of multiple pieces of paper is attached to the front and back surfaces of the input-side rotating plate 20. Grooves several hundred micrometers deep are formed between the friction material to hold clutch oil.

[0022] As shown in Figure 1, the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is positioned concentrically with the clutch housing 30. The clutch center 40 holds a portion of the output side rotating plate 22. The clutch center 40 rotates together with the output shaft 15.

[0023] As shown in Figure 2, the clutch center 40 comprises an annular base wall 43, an outer peripheral wall 45 extending to the right from the base wall 43, an output shaft holding portion 50 provided in the center of the base wall 43, a plurality of center-side cam portions 60, and a center-side fitting portion 58. The center-side cam portions 60 are formed to protrude to the right R from the base wall 43. The center-side cam portions 60 are located radially outside the output shaft holding portion 50.

[0024] As shown in Figure 2, 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 (see Figure 1) 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.

[0025] As shown in Figure 2, the outer peripheral wall 45 is positioned radially outward from the output shaft holding portion 50. The outer peripheral wall 45 is formed in an annular shape when viewed from the axial direction of the output shaft 15. The outer peripheral wall 45 extends in the axial direction of the output shaft 15 (i.e., the left-right direction LR). 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 along the outer peripheral surface 45A of the outer peripheral wall 45 in the axial direction of the clutch center 40 (i.e., the left-right direction LR), 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 a plurality of center-side oil flow holes 49. The center-side fitting teeth 47 hold at least a portion of the output-side rotating plate 22. The plurality of center-side fitting teeth 47 are arranged in the circumferential direction S. Multiple center-side mating teeth 47 are formed at equal intervals in the circumferential direction S. Multiple center-side mating teeth 47 are formed to have the same shape. The center-side mating teeth 47 protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45. Multiple spline grooves 48 are arranged in the circumferential direction S. Multiple spline grooves 48 are formed at equal intervals in the circumferential direction S. Multiple spline grooves 48 are formed to have the same shape.

[0026] As shown in Figure 2, the center-side oil flow hole 49 is formed by penetrating the outer peripheral wall 45 in the radial direction. The center-side oil flow hole 49 is formed between adjacent center-side fitting teeth 47. That is, the center-side oil flow hole 49 is formed in the spline groove 48. The center-side oil flow hole 49 is a hole that allows clutch oil to flow between the inside and outside of the clutch center 40. The center-side oil flow hole 49 is a hole that can discharge, for example, clutch oil that has flowed out from the output shaft 15 into the clutch center 40 to the outside of the clutch center 40. The clutch oil discharged from the center-side oil flow hole 49 is supplied to the input-side rotating plate 20 and the output-side rotating plate 22 located radially outside the center-side oil flow hole 49. The center-side oil flow hole 49 includes a center-side first oil flow hole 49A located radially outward from the center-side cam portion 60, a center-side second oil flow hole 49B located on the first circumferential direction S1 side of the center-side slipper cam surface 60S, and a center-side third oil flow hole 49C located on the second circumferential direction S2 side of the center-side assist cam surface 60A.

[0027] 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 87 (see Figure 4), which will be described later, of the pressure plate 70. The output-side rotating plate 22 is provided so as to be displaceable along the axial direction (i.e., left-right direction L and R) of the clutch center 40. The output-side rotating plate 22 is provided so as to be rotatable integrally with the clutch center 40. The output-side rotating plate 22 is provided so as to be displaceable along the axial direction (i.e., left-right direction L and R) of the pressure plate 70. The output-side rotating plate 22 is provided so as to be rotatable integrally with the pressure plate 70.

[0028] 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.

[0029] 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 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. The center-side cam portion 60 is formed in the base wall 43. The right end of the center-side cam portion 60 is located to the left L of the right end of the outer peripheral wall 45. The center-side cam portions 60 are arranged at equal intervals in the circumferential direction S of the clutch center 40. In this embodiment, the clutch center 40 has three center-side cam portions 60, but the number of center-side cam portions 60 is not limited to three.

[0030] As shown in Figure 2, the center-side cam portion 60 is located radially outside the output shaft holding portion 50. The center-side cam portion 60 has a center-side assist cam surface 60A (see also Figure 3) and a center-side slipper cam surface 60S. The center-side assist cam surface 60A is configured to generate a force (in this case, to the left L) 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 move the pressure plate 70 away from the clutch center 40 (in this case, to move the pressure plate 70 to the right R) 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 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.

[0031] As shown in Figure 2, the clutch center 40 is provided with a plurality of (three in this embodiment) boss portions 54. The boss portions 54 are members that hold the stopper plate 100. 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 right R). The boss portions 54 are provided on the center-side cam portion 60. With respect to the circumferential direction S, the boss portions 54 are provided between the center-side assist cam surface 60A and the center-side slipper cam surface 60S. The boss portions 54 have screw holes 54H into which a bolt 28 (see Figure 1) is inserted. The screw holes 54H extend in the axial direction (i.e., left-right direction LR) of the clutch center 40.

[0032] 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 to the right R of the center-side cam portion 60. The center-side fitting portion 58 is formed on the inner circumferential surface 45B of the outer circumferential wall 45. The center-side fitting portion 58 is configured to be slidably fitted onto the pressure-side fitting portion 88 (see Figure 4), 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 (see Figure 1) relative to the pressure-side fitting portion 88. That is, a gap is formed between the center-side fitting portion 58 and the pressure-side fitting portion 88, which will be described later.

[0033] 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 on the second circumferential direction S2 side of the center-side assist cam surface 60A 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.

[0034] As shown in Figure 1, the pressure plate 70 is provided so as to be able to move toward and away from the clutch center 40. The pressure plate 70 is provided so as to be able to rotate relative to the clutch center 40. The pressure plate 70 is configured 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 is fitted inside the clutch center 40. This provides radial positioning for the pressure plate 70. The pressure plate 70 is provided so as to be able to move relative to the clutch center 40 in the left-right direction L and R. The pressure plate 70 and the clutch center 40 are configured to rotate relative to each other in the circumferential direction S. As shown in Figure 4, 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 right side R and extends radially outward. The body 72 protrudes to the left L of the flange 98. The flange 98 is located at the outer diameter end of the pressure plate 70. The flange 98 is located radially outward from the cylindrical portion 80 (see also Figure 5), which will be described later. The pressure plate 70 holds at least a portion of the multiple output-side rotating plates 22, which are arranged alternately with the input-side rotating plate 20. The flange 98 is configured to press against the input-side rotating plate 20 and the output-side rotating plates 22. The flange 98 is provided so as to be able to clamp the input-side rotating plate 20 and the output-side rotating plate 22 together with the pressure contact member 150 of the centrifugal clutch mechanism 120, which will be described later. As shown in Figure 6C, the flange 98 has a pressing surface 98P capable of pressing against the input-side rotating plate 20 and the output-side rotating plate 22. The pressing surface 98P is a machined surface (e.g., a flat surface) processed by a milling machine or the like. The flange 98 has a recess 98C radially inward from the pressing surface 98P. The recess 98C is recessed from left L to right R. The depth 98L of the recess 98C in the left-right direction LR is smaller than the thickness 21L of the end plate 21 in the left-right direction LR, which will be described later. The depth 98L may be the same as the thickness 21L, or it may be larger than the thickness 21L. As shown in Figure 4, the recess 98C is continuously provided over the entire circumferential direction S of the flange 98. The radial length of the recess 98C is not constant.For example, the radial length from the radially inner end of the recess 98C of the pressing surface 98P (i.e., the radially outer end 98T of the recess 98C) to the pressure-side fitting teeth 87 is shorter than the radial length from the radially inner end of the recess 98C of the pressing surface 98P to the pressure-side fitting portion 88, which will be described later. By providing the recess 98C radially inward from the pressing surface 98P, the right surface 21R of the end plate 21 and the pressing surface 98P can be made to contact more reliably. As shown in Figure 6C, the radially outer end 98T of the recess 98C is located radially outward from the portion 21I of the radially inner end of the end plate 21 that is not held by the pressure-side fitting teeth 87. The radially outer end 98T of the recess 98C is located radially outward from the portion 21I of the radially inner end of the end plate 21 that is not held by the pressure-side fitting teeth 87, when the end plate 21, input-side rotating plate 20, and output-side rotating plate 22 are assembled to the clutch device 10. The radially outer end 98T of the recess 98C is located radially outward from the portion 21I of the radially inner end of the end plate 21 that is not held by the pressure-side fitting teeth 87, regardless of the position of the end plate 21 in the left-right direction LR. By the radially outer end 98T of the recess 98C being located radially outward from the portion 21I of the radially inner end of the end plate 21 that is not held by the pressure-side fitting teeth 87, the right surface 21R of the end plate 21 can be more reliably brought into contact with the entire pressing surface 98P. The radially outer end 98T of the recess 98C is located radially outward from the radially outer end 87T of the pressure-side mating tooth 87. In Figure 6C, the dashed line IL1 is a straight line that passes through the radially outer end 98T of the recess 98C and is parallel to the axis 15CL of the output shaft 15 (see Figure 1). The dashed line IL2 is a straight line that passes through the portion 21I of the radially inner end of the end plate 21 that is not held by the pressure-side mating tooth 87 and is parallel to the axis 15CL of the output shaft 15. The dashed line IL3 is a straight line that passes through the radially outer end 87T of the pressure-side mating tooth 87 and is parallel to the axis 15CL of the output shaft 15.

[0035] As shown in Figure 4, 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 Figure 5).

[0036] The cylindrical portion 80 is formed in the shape of a bottomed cylinder. The cylindrical portion 80 is formed to be recessed from the left L to the right R. 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.

[0037] As shown in Figure 4, 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 to the left L from the flange 98. 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 4, the pressure-side cam portion 90 is located radially outward from the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also Figure 5) 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 toward the clutch center 40 (in this case, to the left L) from the pressure plate 70 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, 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 move the pressure plate 70 away from the clutch center 40 (in this case, to the right R) 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, such as when decelerating. In adjacent pressure-side cam sections 90 with respect to the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam section 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam section 90M are arranged facing each other in the circumferential direction S.

[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 6A. As a result, the operation of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A generates a force L to the left on the pressure plate 70, increasing 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 6B. 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 right R, 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 Figure 4, 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 to the right R 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 4).

[0042] As shown in Figures 4 and 5, the pressure plate 70 has a pressure-side cam hole 83H that penetrates part of the body 72 and flange 98. The pressure-side cam hole 83H is located radially outward from the cylindrical portion 80. The pressure-side cam hole 83H extends radially from the side of the cylindrical portion 80 to radially outward from the pressure-side fitting portion 88. The pressure-side cam hole 83H 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. When viewed from the axial direction of the pressure plate 70, the pressure-side assist cam surface 90A and part of the pressure-side cam hole 83H overlap. The boss portion 54 (see Figure 2) of the clutch center 40 is inserted into the pressure-side cam hole 83H. The boss portion 54 penetrates the pressure-side cam hole 83H.

[0043] As shown in Fig. 4, the pressure plate 70 includes a plurality of pressure-side fitting teeth 87 disposed on the flange 98. The pressure-side fitting teeth 87 hold the output-side rotating plate 22. The pressure-side fitting teeth 87 project leftward L from the flange 98. The pressure-side fitting teeth 87 are located radially outside the cylindrical portion 80. The pressure-side fitting teeth 87 are located radially outside the pressure-side cam portion 90. The pressure-side fitting teeth 87 are located radially outside the pressure-side fitting portion 88. The plurality of pressure-side fitting teeth 87 are arranged in the circumferential direction S. The plurality of pressure-side fitting teeth 87 are arranged at equal intervals in the circumferential direction S. In this embodiment, since some of the pressure-side fitting teeth 87 are removed, the interval of this portion is widened, but the other adjacent pressure-side fitting teeth 87 are arranged at equal intervals. As shown in Fig. 1, the pressure-side fitting teeth 87 hold the end plate 21. The end plate 21 is a plate used to adjust the left-right direction LR interval (i.e., the axial interval of the output shaft 15) between the input-side rotating plate 20 and the output-side rotating plate 22 when the weight member 130 (described later) of the centrifugal clutch mechanism 120 is at the inner position MI in the radial direction. The end plate 21 is provided so as to be movable in the left-right direction LR.

[0044] As shown in Fig. 5, the spring housing portion 84 is formed in the pressure-side cam portion 90. The spring housing portion 84 is located radially outside the cylindrical portion 80. The spring housing portion 84 is formed to be recessed from the right side R to the left side L. The spring housing portion 84 is provided between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S with respect to the circumferential direction S. The spring housing portion 84 is formed in a circular shape when viewed from the axial direction of the output shaft 15. The spring housing portion 84 houses the clutch spring 25 (see Fig. 1).

[0045] As shown in Figure 1, the clutch spring 25 is housed in the spring housing 84. The left end 25L of the clutch spring 25 is in contact with the pressure plate 70. The right end 25R of the clutch spring 25 is in contact with the stopper plate 100. The clutch spring 25 biases the pressure plate 70 toward the clutch center 40 (i.e., toward the left L). The clutch spring 25 is, for example, a coil spring made by winding spring steel in a spiral shape. The clutch spring 25 extends in the left-right direction L and R.

[0046] As shown in Figures 4 and 5, the pressure plate 70 is provided with a plurality of pressure-side oil flow holes 89. The pressure-side oil flow holes 89 include a first pressure-side oil flow hole 89A formed in the cylindrical portion 80 and a second pressure-side oil flow hole 89B formed in the pressure-side cam portion 90. The first pressure-side oil flow hole 89A is formed to penetrate the cylindrical portion 80 radially. The first pressure-side oil flow hole 89A is, for example, a hole that can discharge clutch oil that has flowed into the cylindrical portion 80 to the outside of the cylindrical portion 80. The second pressure-side oil flow hole 89B is formed to penetrate the pressure-side cam portion 90 radially. The second pressure-side oil flow hole 89B is, for example, a hole that can discharge clutch oil that has flowed into the spring housing portion 84 to the outside of the spring housing portion 84.

[0047] 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 to the right R 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 stopper plate 100 is fixed to the boss portion 54 with the clutch spring 25 positioned in the spring housing portion 84.

[0048] As shown in FIG. 1, the centrifugal clutch mechanism 120 is provided within the clutch housing 30. The centrifugal clutch mechanism 120 is provided to the left L of the clutch center 40. The centrifugal clutch mechanism 120 is held by the clutch housing 30. The centrifugal clutch mechanism 120 is provided so as to be rotatable integrally with the clutch housing 30. As shown in FIGS. 7 and 8, the centrifugal clutch mechanism 120 includes a plurality of weight members 130, a holding member 140, a pressing member 150, a spring 160 (see FIG. 9), and a guide member 170. The centrifugal clutch mechanism 120 releases the pressing force between the input-side rotating plate 20 and the output-side rotating plate 22 when the weight member 130 is at the radially inner position MI (see FIGS. 1 and 10A), blocking the transmission of the rotational driving force of the input shaft to the output shaft 15 (i.e., setting the clutch in a disengaged state). In the centrifugal clutch mechanism 120, as the weight member 130 moves from the radially inner position MI to the radially outer position MO (see FIG. 11) (in the process of the weight member 130 moving from the radially inner position MI to the radially outer position MO), the rotational driving force transmitted from the input shaft to the output shaft 15 increases (at this time, a semi-clutch state may be achieved). The centrifugal clutch mechanism 120 presses the input-side rotating plate 20 and the output-side rotating plate 22 together when the weight member 130 is at the radially outer position MO, transmitting the rotational driving force of the input shaft to the output shaft 15 (i.e., setting the clutch in an engaged state). The centrifugal clutch mechanism 120 is configured to be able to press the auxiliary clutch plate 180 (see FIG. 1).

[0049] As shown in FIG. 9, the holding member 140 holds the weight member 130. The holding member 140 holds the weight member 130 so as to be movable between the radially inner position MI (see FIG. 10A) and the radially outer position MO (see FIG. 11). As shown in FIGS. 12 and 13, the holding member 140 is formed in an annular shape. The holding member 140 is formed by die casting of aluminum. The holding member 140 includes a holding-side main body portion 141 and a plurality of holding-side engaging claws 142.

[0050] As shown in Figure 12, the retaining body portion 141 is formed in an annular shape. The retaining body portion 141 includes a first annular portion 143, a second annular portion 144, a plurality of ribs 145, a plurality of housing portions 146, a plurality of connecting portions 147, and a pressing portion 149 (see Figure 1).

[0051] As shown in Figure 12, the first annular portion 143 is formed in an annular shape. A through hole 143H into which the output shaft 15 (see Figure 1) is inserted is formed in the center of the first annular portion 143. The second annular portion 144 is also formed in an annular shape. The second annular portion 144 is located radially outward from the first annular portion 143. The second annular portion 144 is concentric with the first annular portion 143. The radial length of the first annular portion 143 is longer than the radial length of the second annular portion 144.

[0052] As shown in Figure 12, the rib 145 extends radially. The rib 145 is located radially between the first annular portion 143 and the second annular portion 144. The rib 145 is connected to the first annular portion 143. The rib 145 is connected to the second annular portion 144. As shown in Figure 13, the rib 145 connects the first annular portion 143 and the second annular portion 144. At least a portion of the right surface 145R of the rib 145 and the right surface 143R of the first annular portion 143 are formed flush. In this embodiment, the entire right surface 145R of the rib 145, excluding the portion on which the communication portion 147 is formed, and the entire right surface 143R of the first annular portion 143 are formed flush. At least a portion of the right surface 145R of the rib 145 and the right surface 144R of the second annular portion 144 are formed flush. In this embodiment, the entire right surface 145R of the rib 145, excluding the portion where the communication portion 147 is formed, and the entire right surface 144R of the second annular portion 144 are formed flush with each other. The right surface 145R is an example of the first direction side surface of the rib 145, the right surface 143R is an example of the first direction side surface of the first annular portion 143, and the right surface 144R is an example of the first direction side surface of the second annular portion 144.

[0053] As shown in Figures 14 and 15, the rib 145 comprises a rib body portion 145A, a first extension portion 145B, and a second extension portion 145C. The rib body portion 145A extends radially. The rib body portion 145A connects the first annular portion 143 and the second annular portion 144. The rib body portion 145A has an insertion hole 145H into which a rivet 178 (see Figure 8) for fixing the guide member 170 to the holding member 140 is inserted.

[0054] As shown in Figure 14, the first extension portion 145B is located radially inward from the communication portion 147. The first extension portion 145B extends from the rib body portion 145A toward the first circumferential direction S1. The first extension portion 145B is substantially triangular in shape when viewed from the axial direction of the output shaft 15. The first extension portion 145BB has a first guide surface 145BG and a first curved surface 145BE. The first guide surface 145BG extends parallel to the direction of movement MDA (see Figure 10A) of the first weight member 130A (see Figure 10A) which is located toward the first circumferential direction S1 with respect to one of the ribs 145 of the weight member 130. The first guide surface 145BG guides the radial movement of the first weight member 130A. The first curved surface 145BE is located between the first guide surface 145BG and the communication portion 147. The first curved surface 145BE is continuous with the rib body portion 145A.

[0055] As shown in Figure 14, the second extension portion 145C is located radially inward from the communication portion 147. The second extension portion 145C extends from the rib body portion 145A toward the second circumferential direction S2. The second extension portion 145C is substantially triangular in shape when viewed from the axial direction of the output shaft 15. The second extension portion 145C has a second guide surface 145CG and a second curved surface 145CE. The second guide surface 145CG extends parallel to the direction of movement MDB (see Figure 10A) of the second weight member 130B (see Figure 10A) which is located toward the second circumferential direction S2 side with respect to one of the ribs 145 of the weight member 130. The second guide surface 145CG guides the radial movement of the second weight member 130B. The second curved surface 145CE is located between the second guide surface 145CG and the communication portion 147. The second curved surface 145CE is continuous with the rib body portion 145A. The first extension portion 145B and the second extension portion 145C are symmetrical with respect to the rib body portion 145A.

[0056] As shown in Figure 1, the housing portion 146 is formed in the holding-side main body portion 141 so as to be recessed in the axial direction (i.e., left-right direction L and R) of the output shaft 15. The housing portion 146 is recessed from the right R to the left L. As shown in Figure 9, the housing portion 146 is formed between adjacent ribs 145 with respect to the circumferential direction S. The housing portion 146 is formed between the first annular portion 143 and the second annular portion 144 with respect to the radial direction. The housing portion 146 connects the first annular portion 143 and the second annular portion 144. Multiple housing portions 146 are arranged in the circumferential direction S. The housing portion 146 houses the weight member 130. The housing portion 146 houses the weight member 130 so as to be movable in the radial direction. As shown in Figure 16A, the housing portion 146 is provided with a spring housing groove 146N for housing a part of the spring 160. The spring housing groove 146N is formed on the right surface 146R of the housing portion 146. The right surface 146R is an example of a base surface. The spring housing groove 146N is recessed to the left L from the right surface 146R. The spring housing groove 146N extends in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential directions S). The spring housing groove 146N includes a first spring housing groove 146N1 for housing the first spring 161 (see Figure 9), which will be described later, and a second spring housing groove 146N2 for housing the second spring 162. The housing portion 146 is provided with a rolling groove 146P on which the spherical member 135 of the weight member 130, which will be described later, rolls. The rolling groove 146P is formed on the right surface 146R of the housing portion 146. The rolling groove 146P is recessed to the left L from the right surface 146R. The rolling groove 146P extends in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential directions S). The rolling groove 146P includes a first rolling groove 146P1 that accommodates the retaining side first spherical member 135AL, which will be described later, and a second rolling groove 146P2 that accommodates the retaining side second spherical member 135BL. The first rolling groove 146P1 is located on the first circumferential direction S1 side of the first spring housing groove 146N1. The second rolling groove 146P2 is located on the second circumferential direction S2 side of the second spring housing groove 146N2. The main partition wall 146W, which partitions the housing section 146 and to which the radial outer end of the spring 160 makes contact, extends in a direction that intersects (in this case, perpendicular to) the center line CL (see also Figure 11), which passes through the center 130C of the weight member 130 and the center 140C of the holding member 140, when viewed from the axial direction of the output shaft 15.The center line CL is the trajectory traced by the radial movement of the center 130C of the weight member 130. The center 140C coincides with the center of the output shaft 15. The first partition wall 146W1 that demarcates the housing section 146 is located on the first circumferential direction S1 side than the main partition wall 146W. The first partition wall 146W1 is continuous with the main partition wall 146W. The first partition wall 146W1 is inclined with respect to the center line CL. The first partition wall 146W1 is inclined radially inward as it approaches the first circumferential direction S1. When viewed from the axial direction of the output shaft 15, the length of the circumferential direction S of the first partition wall 146W1 is longer than the length of the circumferential direction S of the first contact surface 132A (see Figure 17) of the weight member 130, which will be described later. Furthermore, when viewed from the axial direction of the output shaft 15, the length of the first partition wall 146W1 in the circumferential direction S may be shorter than the length of the first contact surface 132A (see Figure 17) of the weight member 130, which will be described later. The second partition wall 146W2 that partitions the housing section 146 is located on the second circumferential direction S2 side of the main partition wall 146W. The second partition wall 146W2 is continuous with the main partition wall 146W. The second partition wall 146W2 is inclined with respect to the center line CL. The second partition wall 146W2 is inclined radially inward as it goes towards the second circumferential direction S2. When viewed from the axial direction of the output shaft 15, the length of the second partition wall 146W2 in the circumferential direction S is longer than the length of the second contact surface 132B (see Figure 17) of the weight member 130, which will be described later. Furthermore, when viewed from the axial direction of the output shaft 15, the length S in the circumferential direction of the second partition wall 146W2 may be shorter than the length S in the circumferential direction of the second contact surface 132B of the weight member 130 (see Figure 17), which will be described later. The main partition wall 146W, the first partition wall 146W1, and the second partition wall 146W2 in this embodiment are linear (for example, flat) when viewed from the axial direction of the output shaft 15, but may also be curved (for example, a curved surface concave radially outward). The housing portion 146 has a through hole 146H that penetrates in the axial direction of the output shaft 15 (i.e., left-right direction LR). The through hole 146H penetrates the holding member 140. The through hole 146H is located radially inward from the spring housing groove 146N. The through hole 146H is located radially inward from the rib 145. The clutch oil flowing outside the retaining member 140 flows into the housing portion 146 through the through hole 146H.

[0057] As shown in Figure 12, the communication portion 147 connects adjacent housing portions 146 with respect to the circumferential direction S. The communication portion 147 is provided on the rib 145. More specifically, the communication portion 147 is provided on the rib body portion 145A of the rib 145. As shown in Figure 13, the communication portion 147 is formed on the rib 145 so as to be recessed from the right R to the left L. The communication portion 147 is located radially outward from the radial center of the rib 145. The communication portion 147 is adjacent to the second annular portion 144. The right surface 147R of the portion of the rib 145 on which the communication portion 147 is formed is located to the right R of the right surface 146R of the housing portion 146. The right surface 147R is an example of the first direction side surface of the portion on which the communication portion 147 is formed, and the right surface 146R is an example of the first direction side surface of the housing portion 146.

[0058] As shown in Figure 1, the pressing portion 149 is provided on the first annular portion 143. The pressing portion 149 corresponds to the left side of the first annular portion 143. The pressing portion 149 is configured to press the auxiliary clutch plate 180. The pressing portion 149 presses the auxiliary clutch plate 180 to the left L by moving the weight member 130 from the radially inner position MI to the radially outer position MO.

[0059] As shown in Figure 12, the retaining side engaging claw 142 protrudes radially outward from the outer peripheral edge 141E of the retaining side body portion 141 (i.e., the outer peripheral edge 141E of the second annular portion 144). The retaining side engaging claw 142 is integrally formed with the retaining side body portion 141. The retaining side engaging claw 142 is integrally formed with the second annular portion 144. The right surface 142R of the retaining side engaging claw 142 and the right surface 144R of the second annular portion 144 are formed flush. The retaining side engaging claw 142 engages with the clutch housing 30 (see Figure 1). The retaining member 140 is held by the retaining side engaging claw 142 engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. Multiple retaining side engaging claws 142 are arranged in the circumferential direction S. As shown in Figure 11, the retaining-side engaging claw 142 and the first partition wall 146W1 and the second partition wall 146W2 are offset in the circumferential direction S. When the weight member 130 is at the radially outer position MO, the retaining-side engaging claw 142 and the first contact surface 132A and the second contact surface 132B of the weight member 130, which will be described later, are offset in the circumferential direction S. With respect to the circumferential direction S, the retaining-side engaging claw 142 is positioned between the first partition wall 146W1 and the second partition wall 146W2. When the weight member 130 is at the radially outer position MO, the retaining-side engaging claw 142 is positioned between the first contact surface 132A and the second contact surface 132B with respect to the circumferential direction S.

[0060] As shown in Figure 12, the retaining side engaging claw 142 includes a first retaining side engaging claw 142A located radially outside the communicating portion 147 and having the shape of a third outer peripheral edge, a second retaining side engaging claw 142B located radially outside the housing portion 146 and having the shape of a fourth outer peripheral edge, and a third retaining side engaging claw 142C located radially outside the housing portion 146 and having the shape of a third outer peripheral edge. The outer peripheral edges of the first retaining side engaging claw 142A and the third retaining side engaging claw 142C are partially cut out in an arc shape. The outer peripheral edge of the second retaining side engaging claw 142B is formed in a curved shape. The outer peripheral edge of the second retaining side engaging claw 142B may be formed in a straight shape. The first retaining side engaging claw 142A overlaps with the rib 145 when viewed from the radial direction. The second retaining side engaging claw 142B and the third retaining side engaging claw 142C overlap the housing portion 146 when viewed radially. When viewed from the axial direction of the output shaft 15, the two second retaining side engaging claws 142B intersect the center line 140CL passing through the center 140C of the retaining member 140, while the remaining first retaining side engaging claw 142A and third retaining side engaging claw 142C do not intersect the center line 140CL. Here, the center line 140CL is a straight line passing through the housing portion 146. One of the two second retaining side engaging claws 142B may have the shape of a third outer periphery. The retaining side engaging claw 142 is an example of a retaining side projection. The first retaining side engaging claw 142A and the third retaining side engaging claw 142C are examples of first retaining side projections. The second retaining side engaging claw 142B is an example of a second retaining side projection. The first retaining side engaging claw 142A is an example of the outer diameter side thickness portion.

[0061] As shown in Figure 9, the weight member 130 is housed in the housing portion 146 of the holding member 140. Multiple weight members 130 are arranged in the circumferential direction S. The weight member 130 is configured to be movable from an inner radial position MI (see also Figure 10A) to an outer radial position MO (see Figure 11) due to the centrifugal force accompanying the rotation of the clutch housing 30. The weight member 130 is configured to press the contact member 150 toward the right R. The weight member 130 is configured to press the holding member 140 toward the left L. As shown in Figure 9, when no centrifugal force is applied, the weight member 130 is held in the inner radial position MI by the spring 160. As shown in Figure 11, when centrifugal force is applied, the weight member 130 moves radially outward against the biasing force of the spring 160 and moves to the outer radial position MO.

[0062] As shown in Figures 17 and 18, the weight member 130 comprises a weight body 130X, a through hole 133, a cylindrical member 134, a spherical member 135, and a biasing member holding part 136 (see also Figure 20).

[0063] As shown in Figure 10A, the weight body 130X has a first surface 131 (see also Figure 19), a first contact surface 132A, and a second contact surface 132B. The first surface 131 is the radially outer surface. The first surface 131 extends in a direction that intersects (in this case, perpendicular to) the center line CL, which passes through the center 130C of the weight member 130 and the center 140C of the holding member 140, when viewed from the axial direction of the output shaft 15. The first contact surface 132A is located on the first circumferential direction S1 side of the first surface 131. The first contact surface 132A is continuous with the first surface 131. The first contact surface 132A is inclined with respect to the center line CL. The first contact surface 132A is inclined radially inward as it goes towards the first circumferential direction S1. The end 132AS1 of the first contact surface 132A on the first circumferential direction S1 side is located on the second circumferential direction S2 side than the end 146W1S1 of the first partition wall 146W1 on the first circumferential direction S1 side (see Figure 16A). The end 132AS2 of the first contact surface 132A on the second circumferential direction S2 side is located on the first circumferential direction S1 side than the end 146W1S2 of the first partition wall 146W1 on the second circumferential direction S2 side (see Figure 16A). The second contact surface 132B is located on the second circumferential direction S2 side than the first surface 131. The second contact surface 132B is continuous with the first surface 131. The second contact surface 132B is inclined with respect to the center line CL. The second contact surface 132B is inclined radially inward as it approaches the second circumferential direction S2. The end 132BS1 of the second contact surface 132B on the first circumferential direction S1 side is located on the second circumferential direction S2 side than the end 146W2S1 of the second partition wall 146W2 on the first circumferential direction S1 side (see Figure 16A). The end 132BS2 of the second contact surface 132B on the second circumferential direction S2 side is located on the first circumferential direction S1 side than the end 146W2S2 of the second partition wall 146W2 on the second circumferential direction S2 side (see Figure 16A). As shown in Figure 17, when viewed from the axial direction of the output shaft 15, the first straight line L1 passing through the end of the first circumferential direction S1 side and the end of the second circumferential direction S2 side of the first contact surface 132A, and the second straight line L2 passing through the end of the first circumferential direction S1 side and the end of the second circumferential direction S2 side of the second contact surface 132B intersect at a position radially outside the first surface 131.In this embodiment, the first surface 131, the first contact surface 132A, and the second contact surface 132B are linear (e.g., flat) when viewed from the axial direction of the output shaft 15, but may also be curved (e.g., a curved surface concave radially outward). The weight body 130X is formed from, for example, an aluminum alloy.

[0064] As shown in Figure 11, the first contact surface 132A contacts the first partition wall 146W1 of the holding member 140 when the weight member 130 is at the radially outer position MO. The first contact surface 132A makes surface contact with the first partition wall 146W1 of the holding member 140 when the weight member 130 is at the radially outer position MO. Alternatively, a projection may be provided on at least one of the first contact surface 132A and the first partition wall 146W1, so that the first contact surface 132A and the first partition wall 146W1 make point contact. The second contact surface 132B contacts the second partition wall 146W2 of the holding member 140 when the weight member 130 is at the radially outer position MO. The second contact surface 132B makes surface contact with the second partition wall 146W2 of the holding member 140 when the weight member 130 is at the radially outer position MO. Furthermore, a projection may be provided on at least one of the second contact surface 132B and the second partition wall 146W2, so that the second contact surface 132B and the second partition wall 146W2 make point contact. The first surface 131 does not contact the main partition wall 146W of the holding member 140 when the weight member 130 is at the radially outer position MO. That is, when the weight member 130 is at the radially outer position MO, a gap SP is formed between the main partition wall 146W of the holding member 140 and the first surface 131 with respect to the radial direction. Of the weight member 130, a certain surface between the first contact surface 132A and the second contact surface 132B with respect to the circumferential direction S does not contact the holding member 140 when the weight member 130 is at the radially outer position MO.

[0065] As shown in Figure 10A, the weight body 130X has a first circumferential sliding surface 139A and a second circumferential sliding surface 139B. The first circumferential sliding surface 139A slides against the second guide surface 145CG. The first circumferential sliding surface 139A is parallel to the second guide surface 145CG. The second circumferential sliding surface 139B slides against the first guide surface 145BG. The second circumferential sliding surface 139B is parallel to the first guide surface 145BG. The first circumferential sliding surface 139A, the second guide surface 145CG, the second circumferential sliding surface 139B, and the first guide surface 145BG are all parallel to each other. The first circumferential sliding surface 139A is an example of a second weight sliding surface. The second circumferential sliding surface 139B is an example of the first weight sliding surface.

[0066] As shown in Figure 19, the through hole 133 is formed in the weight body 130X. The through hole 133 is a hole that penetrates the weight body 130X in the axial direction of the output shaft 15 (i.e., in the left-right direction L and R). The through hole 133 includes a first through hole 133A and a second through hole 133B. A cylindrical member 134 is provided in the through hole 133 for holding the spherical member 135 so that it can roll. The cylindrical member 134 is fitted inside the through hole 133 and extends in the axial direction of the output shaft 15 (i.e., in the left-right direction L and R). The cylindrical member 134 is molded from a resin that is harder than, for example, the weight member 130 (e.g., the weight body 130X). The cylindrical member 134 may be made of a material that is harder than the weight member 130 (for example, the weight body 130X) and less susceptible to wear by the spherical member 135. Instead of resin, it may be made of steel, SPCE, or the like. The cylindrical member 134 includes a first cylindrical member 134A housed in the first through hole 133A and a second cylindrical member 134B housed in the second through hole 133B. A portion of the spherical member 135 protrudes from the opening of the through hole 133. The spherical member 135 is, for example, a steel ball. The spherical member 135 includes a pressure-contacting first spherical member 135AR and a holding-side first spherical member 135AL (see Figure 20) that are rotatably held by the first cylindrical member 134A. The first spherical member 135AR on the contact side and the first spherical member 135AL on the holding side are aligned in the left-right direction LR. The diameter of the first spherical member 135AL on the holding side is longer than the diameter of the first spherical member 135AR on the contact side. The spherical member 135 includes a second spherical member 135BR on the contact side and a second spherical member 135BL on the holding side (see Figure 20), which are rotatably held by the second cylindrical member 134B. The second spherical member 135BR on the contact side and the second spherical member 135BL on the holding side are aligned in the left-right direction LR. The diameter of the second spherical member 135BL on the holding side is longer than the diameter of the second spherical member 135BR on the contact side. The first spherical member 135AR on the contact side and the second spherical member 135BR on the contact side are provided so as to be in contact with the contact member 150. The first spherical member 135AR and the second spherical member 135BR on the contact side are rotatably mounted on the contact member 150. The first spherical member 135AR and the second spherical member 135BR on the contact side are rotatably mounted on the inclined surface 156 of the contact member 150, which will be described later.The first retaining spherical member 135AL and the second retaining spherical member 135BL are provided so as to be in contact with the retaining member 140. The first retaining spherical member 135AL and the second retaining spherical member 135BL are provided so as to be rotatable relative to the retaining member 140. The first retaining spherical member 135AL and the second retaining spherical member 135BL are provided so as to be in contact with the right surface 146R of the housing portion 146. The first retaining spherical member 135AL and the second retaining spherical member 135BL are provided so as to be rotatable within the rolling groove 146P of the retaining member 140.

[0067] As shown in Figure 10B, when viewed from the axial direction of the output shaft 15, at least a portion of the first partition wall 146W1 is located at a position along the extension of a straight line LX1 that is aligned with the direction of movement of the first holding spherical member 135AL and passes through the first holding spherical member 135AL. The direction of movement of the first holding spherical member 135AL is the direction that intersects the radial direction (i.e., the direction having components of both the radial and circumferential directions S). The first partition wall 146W1 is located on the outer circumference side of the first holding spherical member 135AL. The straight line LX1 is located on the second circumferential direction S2 side of the first partition wall 146W1S1 on the first circumferential direction S1 side. The straight line LX1 is located on the first circumferential direction S1 side of the first partition wall 146W1S2 on the second circumferential direction S2 side. The straight line LX1 that runs along the direction of movement of the first spherical member 135AL and passes through the first spherical member 135AL is a straight line indicating the direction of movement of the first spherical member 135AL, and passing through a part of the first spherical member 135AL. Here, the straight line LX1 passes through the edge of the first spherical member 135AL on the first circumferential direction S1 side. Note that the straight line LX1 may also be a straight line that passes through a part of the first spherical member 135AL on the second circumferential direction S2 side (for example, the edge on the second circumferential direction S2 side) rather than the edge on the first circumferential direction S1 side.

[0068] As shown in Figure 10B, when viewed from the axial direction of the output shaft 15, at least a portion of the second partition wall 146W2 is located at a position along the extension of a straight line LX2 that is aligned with the direction of movement of the second holding spherical member 135BL and passes through the second holding spherical member 135BL. The direction of movement of the second holding spherical member 135BL is the direction that intersects the radial direction (i.e., the direction having components of both the radial and circumferential directions S). The second partition wall 146W2 is located on the outer circumference side of the second holding spherical member 135BL. The straight line LX2 is located on the second circumferential direction S2 side of the second partition wall 146W2S1 on the first circumferential direction S1 side of the second partition wall 146W2S2. The straight line LX2 is located on the first circumferential direction S1 side of the second partition wall 146W2S2 on the second circumferential direction S2 side of the second partition wall 146W2S2. The straight line LX2 that runs along the direction of movement of the retaining second spherical member 135BL and passes through the retaining second spherical member 135BL is a straight line indicating the direction of movement of the retaining second spherical member 135BL, and passing through a part of the retaining second spherical member 135BL. Here, the straight line LX2 passes through the edge of the retaining second spherical member 135BL on the second circumferential direction S2 side. Note that the straight line LX2 may also be a straight line that passes through a portion of the retaining second spherical member 135BL on the first circumferential direction S1 side (for example, the edge on the first circumferential direction S1 side) rather than the edge on the second circumferential direction S2 side.

[0069] As shown in Figure 16B, when viewed from the axial direction of the output shaft 15, at least a portion of the first partition wall 146W1 is located at a position along the extension of the straight line LY1 which is aligned with the direction of movement of the holding side first spherical member 135AL and passes through the first rolling groove 146P1. The first partition wall 146W1 is located on the outer circumference side of the first rolling groove 146P1. The straight line LY1 is located on the second circumferential direction S2 side of the first partition wall 146W1 than the first circumferential direction S1 side end 146W1S1 of the first partition wall 146W1. The straight line LY1 is located on the first circumferential direction S1 side of the first partition wall 146W1 than the second circumferential direction S2 side end 146W1S2 of the first partition wall 146W1. The straight line LY1, which is along the direction of movement of the retaining side first spherical member 135AL and passes through the first rolling groove 146P1, is a straight line indicating the direction of movement of the retaining side first spherical member 135AL and passing through a part of the first rolling groove 146P1. Here, the straight line LY1 passes through the edge of the first rolling groove 146P1 on the first circumferential direction S1 side. Note that the straight line LY1 may also be a straight line that passes through a part of the first rolling groove 146P1 on the second circumferential direction S2 side (for example, the edge on the second circumferential direction S2 side) rather than the edge on the first circumferential direction S1 side.

[0070] As shown in Figure 16B, when viewed from the axial direction of the output shaft 15, at least a portion of the second partition wall 146W2 is located at a position along the extension of the straight line LY2 which is aligned with the direction of movement of the retaining side second spherical member 135BL and passes through the second rolling groove 146P2. The second partition wall 146W2 is located on the outer circumference side of the second rolling groove 146P2. The straight line LY2 is located on the second circumferential direction S2 side of the end 146W2S1 on the first circumferential direction S1 side of the second partition wall 146W2. The straight line LY2 is located on the first circumferential direction S1 side of the end 146W2S2 on the second circumferential direction S2 side of the second partition wall 146W2. The straight line LY2, which is along the direction of movement of the retaining second spherical member 135BL and passes through the second rolling groove 146P2, is a straight line indicating the direction of movement of the retaining second spherical member 135BL and passing through a part of the second rolling groove 146P2. Here, the straight line LY2 passes through the edge of the second rolling groove 146P2 on the second circumferential direction S2 side. Note that the straight line LY2 may also be a straight line that passes through a portion of the second rolling groove 146P2 on the first circumferential direction S1 side (for example, the edge on the first circumferential direction S1 side) rather than the edge of the second circumferential direction S2 side.

[0071] As shown in Figures 18 and 20, the biasing member holder 136 holds the spring 160. The biasing member holder 136 is a recessed groove that extends from the left L to the right R of the weight body 130X and from the radially outer side to the radially inner side. The biasing member holder 136 includes a retaining wall 136W that holds the radially inner end of the spring 160. In this embodiment, the biasing member holder 136 includes a first biasing member holder 136A that holds a first spring 161 (described later) and a second biasing member holder 136B that holds a second spring 162 (described later). The first biasing member holder 136A and the second biasing member holder 136B are located between the first through hole 133A and the second through hole 133B with respect to the circumferential direction S.

[0072] As shown in Figure 9, the spring 160 is positioned between the weight member 130 and the retaining member 140. The spring 160 is an example of a biasing member. The spring 160 is housed in the retaining member 140. The spring 160 is housed in the spring housing groove 146N (see Figure 12) of the retaining member 140. Part of the spring 160 is located inside the weight member 130. That is, part of the spring 160 is located inside the biasing member holding portion 136. The spring 160 biases the weight member 130 radially inward. The spring 160 is, for example, a coil spring. The spring 160 includes a first spring 161 and a second spring 162 arranged in the circumferential direction S. The first spring 161 is an example of a first biasing member. The second spring 162 is an example of a second biasing member. The first spring 161 and the second spring 162 have the same shape. The first spring 161 and the second spring 162 are housed in the first spring housing groove 146N1 and the second spring housing groove 146N2, respectively. The first spring 161 and the second spring 162 bias one weight member 130 radially inward. With respect to the circumferential direction S, the first spring 161 and the second spring 162 are located between the first spherical member 135AR and the second spherical member 135BR on the pressure contact side of the weight member 130. As shown in Figure 24, with respect to the circumferential direction S, the first spring 161 and the second spring 162 are located between the first protrusion 155A and the second protrusion 155B of the pressure contact member 150, which will be described later.

[0073] As shown in Figure 17, the weight member 130 has a housing groove 138. The weight body 130X has a roughly cross-shaped housing groove 138 that is recessed to the left L from the right surface of the weight body 130X. A roughly cross-shaped leaf spring (not shown) is placed in the housing groove 138. The housing groove 138 is located between the first through hole 133A and the second through hole 133B with respect to the circumferential direction S.

[0074] The pressure contact member 150 is configured to press against the input side rotating plate 20 and the output side rotating plate 22 as the weight member 130 moves from the radially inner position MI (see Figure 10A) to the radially outer position MO (see Figure 11). In the process of the weight member 130 moving from the radially inner position MI to the radially outer position MO, the pressure contact member 150 moves in the axial direction of the output shaft 15 (here, to the right R) and presses against the input side rotating plate 20 and the output side rotating plate 22. As shown in Figures 21A and 22, the pressure contact member 150 is formed in an annular shape. The pressure contact member 150 is made of die-cast aluminum. The pressure contact member 150 comprises an annular pressure contact side main body portion 151, a plurality of protrusions 155, and a plurality of pressure contact side engaging claws 152. A through-hole 151H is formed in the center of the main body portion 151 on the pressure contact side, into which the output shaft 15 (see Figure 1) is inserted.

[0075] As shown in Figures 21A and 22, the protrusions 155 project from the pressure-contacting main body 151 in the axial direction of the output shaft 15 (in this case, to the left L). The protrusions 155 extend in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential directions S). Multiple protrusions 155 are arranged in the circumferential direction S of the pressure-contacting main body 151. Multiple protrusions 155 are spaced apart from each other. As shown in Figure 23, a single weight member 130 is configured to have contact with multiple (in this case, two, but there may be three or more) protrusions 155. As shown in Figure 1, the protrusions 155 have an inclined surface 156 that contacts the weight member 130. More specifically, the inclined surface 156 contacts the spherical members 135 of the weight member 130 (pressure-contacting first spherical member 135AR and pressure-contacting second spherical member 135BR). The inclined surface 156 is inclined with respect to the axial direction (i.e., left-right direction LR) of the output shaft 15. The inclined surface 156 is inclined to the left L as it extends radially outward. At least a portion of the inclined surface 156 of the multiple protrusions 155 that contact one weight member 130 are located on the same plane. Guide grooves 157 are formed in the inclined surface 156 to guide the radial movement of the spherical member 135. The guide grooves 157 extend in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential direction S). The guide grooves 157 extend parallel to the center line CL.

[0076] As shown in Figure 24, the multiple protrusions 155 include a first protrusion 155A and a second protrusion 155B that contact one weight member 130. The first protrusion 155A and the second protrusion 155B extend parallel to the center line CL. A first guide groove 157A is formed on the inclined surface 156 of the first protrusion 155A, which guides the radial movement of the pressure-contacting first spherical member 135AR. The center line CLA of the first guide groove 157A is parallel to the center line CL. A second guide groove 157B is formed on the inclined surface 156 of the second protrusion 155B, which guides the radial movement of the pressure-contacting second spherical member 135BR. The center line CLB of the second guide groove 157B is parallel to the center line CL. The first guide groove 157A and the second guide groove 157B are parallel to each other. As shown in Figure 21A, the first circumferential S1 side edge 155AS1 and the second circumferential S2 side edge 155AS2 of the first protrusion 155A, which extend in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential directions S), and the first circumferential S1 side edge 155BS1 and the second circumferential S2 side edge 155BS2 of the second protrusion 155B, which extend in a direction intersecting the radial direction (i.e., a direction having components of both the radial and circumferential directions S), are parallel to each other. At least a portion of the bottom surfaces 157P (see also Figure 21B) that define the guide grooves 157 formed on the inclined surfaces 156 of the multiple protrusions 155 are located on the same plane. Here, at least a portion of the bottom surface 157P defining the first guide groove 157A formed on the inclined surface 156 of the first protrusion 155A and at least a portion of the bottom surface 157P defining the second guide groove 157B formed on the inclined surface 156 of the second protrusion 155B are located on the same plane. For example, the entire bottom surface 157P defining the first guide groove 157A and the entire bottom surface 157P defining the second guide groove 157B are located on the same plane.

[0077] As shown in Figure 21A, the pressure-contact side engaging claw 152 protrudes radially outward from the outer peripheral edge 151E of the pressure-contact side main body portion 151. The pressure-contact side engaging claw 152 is integrally formed with the pressure-contact side main body portion 151. The left surface 152L of the pressure-contact side engaging claw 152 and the left surface 151L of the pressure-contact side main body portion 151 are formed flush. The pressure-contact side engaging claw 152 engages with the clutch housing 30 (see Figure 1). The pressure contact member 150 is held by the pressure-contact side engaging claw 152 engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. Multiple pressure-contact side engaging claws 152 are arranged in the circumferential direction S. The pressure-contact side engaging claws 152 and the first protrusion 155A and the second protrusion 155B are offset in the circumferential direction S. With respect to the circumferential direction S, the pressure-contact side engaging claw 152 is positioned between the first protrusion 155A and the second protrusion 155B.

[0078] As shown in Figure 21A, the pressure-contact side engaging claw 152 includes a first pressure-contact side engaging claw 152A having the shape of a first outer peripheral edge, a second pressure-contact side engaging claw 152B having the shape of a second outer peripheral edge, and a third pressure-contact side engaging claw 152C having the shape of a first outer peripheral edge. The outer peripheral edges of the first pressure-contact side engaging claw 152A and the third pressure-contact side engaging claw 152C are partially cut out in an arc shape. The outer peripheral edge of the second pressure-contact side engaging claw 152B is formed in a curved shape. However, the outer peripheral edge of the second pressure-contact side engaging claw 152B may be formed in a straight shape. The first pressure-contact side engaging claw 152A is located between a first protrusion 155A that contacts one weight member 130 (for example, the first weight member 130A shown in Figure 23) and a second protrusion 155B that contacts another weight member 130 (for example, the second weight member 130B shown in Figure 23) with respect to the circumferential direction S. The second pressure-contact side engaging claw 152B and the third pressure-contact side engaging claw 152C are located, respectively, between the first protrusion 155A and the second protrusion 155B that contact one weight member 130 with respect to the circumferential direction S. The first pressure-contact side engaging claw 152A, the second pressure-contact side engaging claw 152B, and the third pressure-contact side engaging claw 152C do not overlap with the protrusion 155 when viewed from the radial direction. As shown in Figures 23 and 24, the second pressure-contact side engaging claw 152B is located radially outward of the weight member 130. The first pressure-contact side engaging claw 152A is located on the first circumferential direction S1 side and the second circumferential direction S2 side of the second pressure-contact side engaging claw 152B, respectively. The third pressure-contact side engaging claw 152C is located radially outward of the weight member 130. The first pressure-contact side engaging claw 152A is located on the first circumferential direction S1 side and the second circumferential direction S2 side of the third pressure-contact side engaging claw 152C, respectively. As shown in Figure 7, the first pressure-contact side engaging claw 152A faces the first retaining side engaging claw 142A. The second pressure-contact side engaging claw 152B faces the second retaining side engaging claw 142B. The third pressure-contact side engaging claw 152C faces the third retaining side engaging claw 142C. When viewed from the axial direction of the output shaft 15, the two second pressure-contact side engaging claws 152B intersect the center line 150CL, which passes through the center 150C of the pressure-contact member 150, while the remaining first pressure-contact side engaging claws 152A and third pressure-contact side engaging claws 152C do not intersect the center line 150CL. Here, the center line 150CL is a straight line passing between the first protrusion 155A and the second protrusion 155B.One of the two second pressure-contact side engaging claws 152B may have the shape of the first outer peripheral edge. The pressure-contact side engaging claw 152 is an example of a pressure-contact side projection. The first pressure-contact side engaging claw 152A and the third pressure-contact side engaging claw 152C are examples of the first pressure-contact side projection. The second pressure-contact side engaging claw 152B is an example of the second pressure-contact side projection.

[0079] As shown in Figure 21A, when viewed from the axial direction, a part of the contact member 150 (here, the contact-side main body portion 151) and the center-side fitting teeth 47 overlap. As shown in Figure 1, when the weight member 130 is in the radially inner position MI, a gap SPI is formed between a part of the contact member 150 (here, the contact-side main body portion 151) and the center-side fitting teeth 47 with respect to the axial direction of the output shaft 15 (i.e., the left-right direction LR), allowing the contact member 150 to move in the axial direction. As shown in Figure 27, when the weight member 130 is in the radially outer position MO, a gap SPO is formed between a part of the contact member 150 (here, the contact-side main body portion 151) and the center-side fitting teeth 47 with respect to the axial direction of the output shaft 15 (i.e., the left-right direction LR), allowing the contact member 150 to move in the axial direction. Throughout the entire range of the movement of the weight member 130 from its radially inner position MI to its radially outer position MO, a gap is formed between a portion of the pressure contact member 150 (in this case, the pressure contact side main body portion 151) and the center side fitting teeth 47 with respect to the axial direction of the output shaft 15. That is, when the weight member 130 moves from its radially inner position MI to its radially outer position MO, a gap is always formed between a portion of the pressure contact member 150 (in this case, the pressure contact side main body portion 151) and the center side fitting teeth 47 with respect to the axial direction of the output shaft 15. The axial lengths of the gaps SPI and SPO are longer than the axial length of the output side rotating plate 22. At least a portion of the input side rotating plate 20 is located radially outside the gaps SPI and SPO. At least a portion of the specific input-side rotating plate 20SP, which contacts the pressure contact member 150, is located radially outside the gaps SPI and SPO. The specific input-side rotating plate 20SP is the input-side rotating plate 20 located furthest to the left L among the input-side rotating plates 20. When the weight member 130 is in the radially inward position MI, the length LS1 of the gap SPI in the left-right direction LR is more than half the length LS2 of the specific input-side rotating plate 20SP in the left-right direction LR. A portion of the pressure contact member 150 that can contact the input-side rotating plate 20 or the output-side rotating plate 22 may be located radially outside the gaps SPI and SPO. Note that in Figure 21A, only one center-side fitting tooth 47 of the clutch center 40 is shown.

[0080] As shown in Figure 7, the guide member 170 is positioned between the holding member 140 and the pressure contact member 150 with respect to the axial direction (i.e., left-right direction L / R) of the output shaft 15. The guide member 170 is attached to the holding member 140. The guide member 170 is fixed to the surface of the holding member 140 on which the housing portion 146 is formed. The guide member 170 holds the weight member 130 so that it can move radially. The guide member 170 guides the radial movement of the weight member 130. As shown in Figure 25, the guide member 170 is formed in an annular shape. The guide member 170 comprises a first annular portion 173, a second annular portion 174, and a plurality of ribs 175.

[0081] As shown in Figure 25, the first annular portion 173 is formed in an annular shape. A through hole 173H into which the output shaft 15 (see Figure 1) is inserted is formed in the center of the first annular portion 173. The second annular portion 174 is also formed in an annular shape. The second annular portion 174 is located radially outward from the first annular portion 173. The second annular portion 174 is concentric with the first annular portion 173. The radial length of the first annular portion 173 is longer than the radial length of the second annular portion 174.

[0082] As shown in Figure 25, the rib 175 extends radially. The rib 175 connects the first annular portion 173 and the second annular portion 174. As shown in Figure 8, the rib 175 includes a first rib 175A that overlaps with the weight member 130 when viewed from the axial direction (i.e., left-right direction LR) of the output shaft 15, and a second rib 175B that overlaps with the rib 145 of the holding member 140. The first rib 175A guides the radial movement of the weight member 130. A portion of the first rib 175A is housed in the housing groove 138 of the weight member 130. As shown in Figure 25, with respect to the circumferential direction S, the first rib 175A is located between the first protrusion 155A and the second protrusion 155B of the pressure contact member 150. The second rib 175B has an insertion hole 175H into which a rivet 178 (see Figure 8) for fixing the guide member 170 to the holding member 140 is inserted.

[0083] As shown in Figure 26, when the weight member 130 is in the radially inner position MI (see Figure 1) and viewed from the radial direction, at least a portion of the first protrusion 155A and the second protrusion 155B overlap with the guide member 170. In this embodiment, when the weight member 130 is in the radially inner position MI and viewed from the radial direction, a portion of the first protrusion 155A and the second protrusion 155B is located closer to the holding member 140 (i.e., to the left L) than the guide member 170. Note that the weight member 130 is not shown in Figure 26.

[0084] As shown in Figure 1, the auxiliary clutch plate 180 is provided inside the clutch housing 30. The auxiliary clutch plate 180 is fixed to the output shaft 15. The auxiliary clutch plate 180 has an insertion hole 180H into which the output shaft 15 is inserted and spline-fitted. The auxiliary clutch plate 180 is positioned to the left L of a part of the centrifugal clutch mechanism 120. The auxiliary clutch plate 180 is adjacent to the clutch center 40.

[0085] The auxiliary clutch plate 180 is configured to be released from the pressure applied by the centrifugal clutch mechanism 120 (in this case, the pressing portion 149 of the holding member 140) when the pressure between the input-side rotating plate 20 and the output-side rotating plate 22 is released (i.e., when the weight member 130 is in the radially inner position MI), thereby blocking the transmission of the rotational driving force of the input shaft to the output shaft 15. As the weight member 130 moves from the radially inner position MI to the radially outer position MO, the auxiliary clutch plate 180 is pressed by the centrifugal clutch mechanism 120 (in this case, the pressing portion 149 of the holding member 140), increasing the rotational driving force transmitted from the input shaft to the output shaft 15.

[0086] The centrifugal clutch mechanism 120 of this embodiment is configured in a so-called normally open state. When the throttle of a saddle-type vehicle (for example, a motorcycle) is not operated, that is, when the engine is idling, the weight member 130 is in the radially inward position MI. When the weight member 130 is in the radially inward position MI, the centrifugal clutch mechanism 120 releases the contact force between the input-side rotating plate 20 and the output-side rotating plate 22, thereby blocking the transmission of the rotational driving force of the input shaft to the output shaft 15. When the weight member 130 is in the radially inward position MI, the input-side rotating plate 20 and the output-side rotating plate 22 are separated from each other, and there is a gap between the input-side rotating plate 20 and the output-side rotating plate 22. In other words, the clutch is disengaged.

[0087] When the throttle is operated to increase the engine speed from idling speed (when the throttle is not operated), the weight member 130 begins to move from the radially inner position MI to the radially outer position MO due to centrifugal force. As the weight member 130 begins to move toward the radially outer position MO, the weight member 130 presses the pressure contact member 150 to the right R. When the weight member 130 reaches the first position in the radial direction, the pressure contact member 150 presses the input side rotating plate 20 and the output side rotating plate 22 against each other, creating a semi-clutch state. That is, the pressure contact member 150 presses the input side rotating plate 20 and the output side rotating plate 22 against each other, creating a semi-clutch state between a state where the clutch is disengaged and a state where the clutch is engaged (i.e., all input side rotating plates 20 and all output side rotating plates 22 are in pressure contact with each other). When the input-side rotating plate 20 and the output-side rotating plate 22 come into contact with each other, the transmission of rotational driving force from the input shaft to the output shaft 15 begins. That is, the saddle-type vehicle starts moving. In the half-clutch state, the contact force between the input-side rotating plate 20 and the output-side rotating plate 22 is intermediate, so the rotational driving force from the engine is transmitted to the transmission and drive wheels (rear wheels), etc., with slippage. Note that the half-clutch state may occur at the same time that the weight member 130 begins to move from the radially inner position MI to the radially outer position MO.

[0088] When the throttle is further operated from a partially clutched state to increase the engine speed, the centrifugal force acting on the weight member 130 increases. At this point, the pressure plate 70 is biased to the left L by the biasing force of the clutch spring 25 and is in contact with the clutch center 40. Therefore, when the centrifugal force acting on the weight member 130 increases, the weight member 130 remains in a first position radially until the pressing force that the weight member 130 exerts on the pressure contact member 150 to the right R exceeds the biasing force of the clutch spring 25, pressing the input side rotating plate 20 and the output side rotating plate 22 via the pressure contact member 150. As a result, all of the input side rotating plates 20 and all of the output side rotating plates 22 are pressed against each other (in close contact), and the clutch is engaged. Furthermore, after the weight member 130 moves radially outward from the first position, all input-side rotating plates 20 and all output-side rotating plates 22 may be pressed against each other (closely in contact), that is, in a state where the clutch is engaged.

[0089] When the throttle is further operated from the clutch engaged state to further increase the engine speed, the pressing force of the weight member 130 pressing the contact member 150 to the right (R) exceeds the biasing force of the clutch spring 25, causing the weight member 130 to start moving radially outward from the first position. As a result, the contact member 150 moves further to the right (R), and the pressure plate 70 is pressed to the right (R) by the contact member 150 and moves to the right (R). The weight member 130 moves to the radially outward position MO as the engine speed increases. Furthermore, as the pressure plate 70 moves away from the clutch center 40, the center-side assist cam surface 60A and the pressure-side assist cam surface 90A act on the pressure plate 70 to generate a force (so-called assist force) in the direction toward the clutch center 40 (in this case, to the left (L)), increasing the contact force between the input-side rotating plate 20 and the output-side rotating plate 22. Furthermore, the pressure-side assist cam surface 90A and the center-side assist cam surface 60A may be in contact at an engine speed lower than the engine speed at which the saddle-type vehicle starts. Alternatively, the pressure-side assist cam surface 90A and the center-side assist cam surface 60A may be in contact at an engine speed at which the saddle-type vehicle starts. Alternatively, the pressure-side assist cam surface 90A and the center-side assist cam surface 60A may be in contact at an engine speed higher than the engine speed at which the saddle-type vehicle starts. In this case, the pressure-side assist cam surface 90A and the center-side assist cam surface 60A may be in contact after the pressure plate 70 has separated from the clutch center 40.

[0090] In this embodiment, as the weight member 130 moves from the radially inner position MI to the radially outer position MO, the rotational driving force transmitted from the input shaft to the output shaft 15 increases continuously. However, the transmitted rotational driving force does not necessarily have to increase continuously. For example, the rotational driving force transmitted from the input shaft to the output shaft 15 may be kept constant for a portion of the time it takes for the weight member 130 to move from the radially inner position MI to the radially outer position MO, thereby making the increase in rotational driving force discontinuous. Furthermore, the increase in rotational driving force transmitted from the input shaft to the output shaft 15 does not have to be constant. For example, the increase in rotational driving force transmitted from the input shaft to the output shaft 15 may change as the weight member 130 moves from the radially inner position MI to the radially outer position MO.

[0091] As described above, according to the clutch device 10 of this embodiment, the weight member 130 has a first surface 131, a first contact surface 132A that contacts the first partition wall 146W1 that partitions the housing portion 146 of the holding member 140, and a second contact surface 132B that contacts the second partition wall 146W2 that partitions the housing portion 146. A first straight line L1 passing through one end and the other end in the circumferential direction of the first contact surface 132A, and a second straight line L2 passing through one end and the other end in the circumferential direction of the second contact surface 132B, intersect at a position radially outside the first surface 131. According to the above embodiment, since the first contact surface 132A and the second contact surface 132B are inclined with respect to the center line CL passing through the center 130C of the weight member 130 and the center 140C of the holding member 140 when viewed from the axial direction of the output shaft 15, when the weight member 130 moves to a radially outward position MO, and the first contact surface 132A comes into contact with the first partition wall 146W1 and the second contact surface 132B comes into contact with the second partition wall 146W2, the movement of the weight member 130 in the circumferential direction S can be suppressed. This suppresses a decrease in ride comfort. In addition, since the part of the holding member 140 that receives the pressing force from the weight member 130 is stabilized, the strength of the holding member 140 can be ensured.

[0092] In the clutch device 10 of this embodiment, when the weight member 130 is in the radially outer position MO, a gap SP is formed between the holding member 140 and the first surface 131 in the radial direction. According to the above embodiment, when the weight member 130 moves to the radially outer position MO and the first contact surface 132A comes into contact with the first partition wall 146W1 and the second contact surface 132B comes into contact with the second partition wall 146W2, the movement of the weight member 130 in the circumferential direction S can be suppressed more reliably.

[0093] In the clutch device 10 of this embodiment, when the weight member 130 is in the radially outer position MO, the retaining side engaging claw 142 and the first contact surface 132A and the second contact surface 132B are offset in the circumferential direction S. According to the above embodiment, when the weight member 130 moves to the radially outer position MO, the pressing force from the weight member 130 is not directly transmitted to the retaining side engaging claw 142, thereby preventing excessive load from being placed on the retaining side engaging claw 142.

[0094] In the clutch device 10 of this embodiment, when the weight member 130 is in the radially outer position MO, the retaining side engaging claw 142 is positioned between the first contact surface 132A and the second contact surface 132B with respect to the circumferential direction S. According to the above embodiment, when the weight member 130 moves to the radially outer position MO, the pressing force from the weight member 130 is not directly transmitted to the retaining side engaging claw 142, thereby preventing excessive load from being placed on the retaining side engaging claw 142.

[0095] In the clutch device 10 of this embodiment, the first contact surface 132A is configured to be able to make surface contact with the first partition wall 146W1, and the second contact surface 132B is configured to be able to make surface contact with the second partition wall 146W2. According to the above embodiment, the movement of the weight member 130 in the circumferential direction S can be suppressed more reliably.

[0096] 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.

[0097] In the embodiment described above, the rib 145 was connected to the second annular portion 144, but it is not limited to this. For example, as shown in Figure 28, the rib 145 does not have to be connected to the second annular portion 144. In this case, the communication portion 147 is provided between the second annular portion 144 and the rib 145 in the radial direction. The right surface 147R of the portion in which the communication portion 147 is formed and the right surface 146R of the housing portion 146 are formed flush. The communication portion 147 may also be provided between the first annular portion 143 and the rib 145 in the radial direction. Furthermore, the communication portion 147 is a recessed groove formed in the rib 145 so as to be recessed from the right R to the left L, but it may also be a through hole that penetrates the rib 145 in the circumferential direction S.

[0098] As shown in Figure 29, the retaining body portion 141 may have an inner diameter thickened portion 141T that protrudes radially inward from the inner peripheral edge of the second annular portion 144. In this case, the first surface 131 of the weight member 130 does not contact the main partition wall 146W of the retaining member 140 when the weight member 130 is in the radially outer position MO.

[0099] In the embodiment described above, the first spring 161 and the second spring 162 were located between the first retaining spherical member 135AL and the second retaining spherical member 135BL of the weight member 130 with respect to the circumferential direction S, but are not limited to this. For example, as shown in Figure 30, the first retaining spherical member 135AL and the second retaining spherical member 135BL of the weight member 130 may be located between the first spring 161 and the second spring 162 with respect to the circumferential direction S.

[0100] As shown in Figure 31, the inclined surface 156 of the pressure contact member 150 may be curved. The inclined surface 156 is curved so as to be recessed to the right R. The radially outer portion of the inclined surface 156 is located closer to the weight member 130 (i.e., to the left L) than the radially inner portion.

[0101] In the above-described embodiment, a guide groove 157 was provided on the protrusion 155 to guide the radial movement of the spherical member 135 of the weight member 130, but the embodiment is not limited to this. For example, a projection may be provided on the protrusion 155 that extends toward the weight member 130, and a guide groove may be provided on the weight member 130 to guide the radial movement of this projection.

[0102] The first circumferential S1 side end 132AS1 of the first contact surface 132A (see Figure 17) may be located closer to the first circumferential S1 direction than the first circumferential S1 side end 146W1S1 of the first partition wall 146W1 (see Figure 16A). The second circumferential S2 side end 132AS2 of the first contact surface 132A (see Figure 17) may be located closer to the second circumferential S2 direction than the second circumferential S2 side end 146W1S2 of the first partition wall 146W1 (see Figure 16A). Also, the first circumferential S1 side end 132BS1 of the second contact surface 132B (see Figure 17) may be located closer to the first circumferential S1 direction than the first circumferential S1 side end 146W2S1 of the second partition wall 146W2 (see Figure 16A). The end portion 132BS2 of the second contact surface 132B on the second circumferential direction S2 side (see Figure 17) may be located on the second circumferential direction S2 side than the end portion 146W2S2 of the second partition wall 146W2 on the second circumferential direction S2 side (see Figure 16A).

[0103] In the embodiment described above, the first annular portion 143 and the second annular portion 144 are formed continuously in the circumferential direction, but are not limited thereto. For example, they may be formed discontinuously in the circumferential direction by forming radially extending grooves in the first annular portion 143 and / or the second annular portion 144.

[0104] In the embodiment described above, as shown in Figure 1, the pressure plate 70 holds one output-side rotating plate 22, but it may also hold multiple output-side rotating plates 22. Furthermore, the clutch center 40 holds multiple output-side rotating plates 22, but it may also not hold any output-side rotating plates 22, with all output-side rotating plates 22 being held by the pressure plate 70.

[0105] In the embodiment described above, the multiple protrusions 155 included a first protrusion 155A and a second protrusion 155B that contact one weight member 130, but the first protrusion 155A and the second protrusion 155B may be formed integrally. As shown in Figure 32, a first guide groove 157A and a second guide groove 157B may be formed on the inclined surface 156 of the protrusion 155. Here, at least a portion of the bottom surface 157P defining the first guide groove 157A formed on the inclined surface 156 of the protrusion 155 and at least a portion of the bottom surface 157P defining the second guide groove 157B formed on the inclined surface 156 of the protrusion 155 are located on the same plane. For example, the entire bottom surface 157P defining the first guide groove 157A and the entire bottom surface 157P defining the second guide groove 157B are located on the same plane. Note that the cross-sectional view along line A-A in Figure 32 is the same as that in Figure 21A.

[0106] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 30 Clutch housing 40 Clutch center 70 Pressure plate 120 Centrifugal clutch mechanism 130 Weight member 131 First surface 132A First contact surface 132B Second contact surface 140 Retaining member 142 Retaining side engaging claw 146 Housing section 146W1 First compartment wall 146W2 Second compartment wall

Claims

1. 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 rotated 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 and move away from the clutch center, which holds at least a portion of a plurality of output-side rotating plates arranged alternately with the input-side rotating plates, and which can press the input-side rotating plates and the output-side rotating plates; and a weight member configured to be movable from a radially inner position to a radially outer position by the centrifugal force accompanying the rotation of the clutch housing, and which, when the weight member is in the radially inner position, releases the pressure force between the input-side rotating plates and the output-side rotating plates, thereby interrupting the transmission of the rotational driving force of the input shaft to the output shaft, and which increases the rotational driving force transmitted from the input shaft to the output shaft as the weight member moves from the radially inner position to the radially outer position, The centrifugal clutch mechanism includes a holding member that holds the weight member so as to be movable between an inner position in the radial direction and an outer position in the radial direction, the holding member includes a housing portion for housing the weight member, the weight member has a first surface which is the outer surface in the radial direction and extends in a direction intersecting a center line passing through the center of the weight member and the center of the holding member when viewed from the axial direction of the output shaft, a first contact surface which is located on one side in the circumferential direction from the first surface, is inclined with respect to the center line and contacts a first compartment wall which defines the housing portion of the holding member when it is in the outer position in the radial direction, and a second contact surface which is located on the other side in the circumferential direction from the first surface, is inclined with respect to the center line and contacts a second compartment wall which defines the housing portion of the holding member when it is in the outer position in the radial direction A clutch device in which, when viewed from the axial direction, a first straight line passing through one circumferential end and the other circumferential end of the first contact surface and a second straight line passing through one circumferential end and the other circumferential end of the second contact surface intersect at a position radially outward from the first surface.

2. The clutch device according to claim 1, wherein when the weight member is in an outer position in the radial direction, a gap is formed between the holding member and the first surface in the radial direction.

3. The clutch device according to claim 1, wherein the retaining member comprises a retaining-side main body portion formed in an annular shape and having the housing portion formed thereon, and a retaining-side engaging claw protruding radially outward from the outer peripheral edge of the retaining-side main body portion and engaging with the clutch housing, and when the weight member is in the radially outward position, the retaining-side engaging claw and the first contact surface and the second contact surface are offset in the circumferential direction.

4. The clutch device according to claim 3, wherein when the weight member is located on the outer side in the radial direction, the retaining side engaging claw is positioned between the first contact surface and the second contact surface in the circumferential direction.

5. The clutch device according to claim 1, wherein the first contact surface is configured to be able to make surface contact with the first partition wall, and the second contact surface is configured to be able to make surface contact with the second partition wall.

6. The clutch device according to claim 1, wherein the weight member comprises a weight body, a through hole formed in the weight body and penetrating in the axial direction, and a spherical member that partially protrudes from the opening of the through hole and contacts the base surface of the housing, and at least a part of the first partition wall is located at a position along the direction of movement of the spherical member and passing through the spherical member when viewed from the axial direction.

7. The clutch device according to claim 1, wherein the weight member comprises a weight body, a through hole formed in the weight body and penetrating in the axial direction, and a spherical member that partially protrudes from the opening of the through hole and contacts the base surface of the housing, and at least a part of the second partition wall is located at a position along the direction of movement of the spherical member and passing through the spherical member when viewed from the axial direction.

8. The clutch device according to claim 1, wherein the weight member comprises a weight body, a through hole formed in the weight body and penetrating in the axial direction, and a spherical member that partially protrudes from the opening of the through hole and rolls in a rolling groove formed on the base surface of the housing, and at least a part of the first partition wall is located at a position along a straight line that is aligned with the direction of movement of the spherical member and passes through the rolling groove when viewed from the axial direction.

9. The clutch device according to claim 1, wherein the weight member comprises a weight body, a through hole formed in the weight body and penetrating in the axial direction, and a spherical member that partially protrudes from the opening of the through hole and rolls in a rolling groove formed on the base surface of the housing, and at least a part of the second partition wall is located at a position along a straight line that is aligned with the direction of movement of the spherical member and passes through the rolling groove when viewed from the axial direction.

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