Clutch device

Abstract

To provide a clutch device in which damage to the engaging claws is suppressed. 【Solution means】The clutch device 10 includes a centrifugal clutch mechanism 120 having a weight member 130. The centrifugal clutch mechanism 120 includes a holding member 140 that holds the weight member 130, a spring 160 that biases the weight member 130, and a pressing member 150 that presses the input-side rotating plate 20 and the output-side rotating plate 22 together. The holding member 140 includes an engaging claw 143 that protrudes from the outer peripheral edge 141E of the main body 141 toward the outer side M1 in the radial direction M and engages with the clutch housing 30, and a housing recess 145 that houses the weight member 130. The main body 141 includes a wall portion 141A that is located between the engaging claw 143 and the housing recess 145 in the radial direction M, and a protruding portion 141B that protrudes from the wall portion 141A toward the inner side M2 in the radial direction M and partitions a part of the housing recess 145, and has a thick portion 141T including these.

Description

Technical Field

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

Background Art

[0002] A saddle-type vehicle such as a motorcycle is provided with a clutch device capable of transmitting and interrupting the rotational driving force of a drive source such as an engine to a drive wheel. For example, Patent Document 1 discloses a clutch device having 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 that can approach or separate from the clutch center.

[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 holding member has an engagement claw that engages with the clutch housing and is configured to rotate together with the clutch housing. The engagement claw is located on the outer side in the radial direction of 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, and is configured to transmit the driving force of the engine to the wheels by pressing 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).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, since the rotational driving force of the clutch housing is transmitted to the holding member via the engaging claws, a relatively large load is applied to the engaging claws. If the engaging claws are damaged, there may arise a problem that the rotational driving force of the clutch housing cannot be sufficiently transmitted to the weight member. For this reason, there is a demand for providing a clutch device in which damage to the engaging claws is suppressed.

[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 damage to the engaging claws is suppressed.

Means for Solving the Problem

[0007] The inventor of the present application has decided to increase the strength against torsion by increasing the thickness of the engaging claws. Furthermore, it has been discovered that a relatively large load is applied to the engaging claws by the load from the weight member when the weight member located inside in the radial direction of the engaging claws moves from the position inside in the radial direction to the position outside by centrifugal force. Therefore, it has been decided to improve the strength of the entire engaging claws by changing the shape around the engaging claws.

[0008] The clutch device according to the present invention is a clutch device that transmits or shuts off the rotational driving force of an input shaft to an output shaft, and is housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and a clutch center that is rotationally driven together with the output shaft, and is provided so as to be able to approach or separate from the clutch center, and holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates, and a pressure member that can press the input-side rotating plates and the output-side rotating plates, and has a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position by centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, the input-side rotating plates and the output-side rotating plates are brought into pressure contact to make it possible to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are in the inner position in the radial direction, the pressure contact force between the input-side rotating plates and the output-side rotating plates is released to cut off the transmission of the rotational driving force of the input shaft to the output shaft, and a centrifugal clutch mechanism, and the centrifugal clutch mechanism includes a holding member that holds the weight members so as to be movable between the inner position in the radial direction and the outer position in the radial direction, a biasing member provided on the holding member that biases the weight members toward the inner side in the radial direction, and a pressure contact member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction and brings the input-side rotating plates and the output-side rotating plates into pressure contact, and the holding member includes a main body formed in a ring shape, an engaging claw that projects from the outer peripheral edge of the main body toward the outer side in the radial direction and engages with the clutch housing, and a housing recess formed in the main body so as to be recessed in the axial direction of the output shaft and housing the weight members so as to be movable in the radial direction, and the main body includes a wall portion located between the engaging claw and the housing recess in the radial direction, and a protruding portion that projects from the wall portion toward the inner side in the radial direction and partitions a part of the housing recess, and has a thick portion including them.

[0009] According to the clutch device of the present invention, the main body of the holding member includes a wall portion positioned between the engaging claw and the accommodating recess in the radial direction, and a protruding portion that protrudes from the wall portion toward the inner side in the radial direction and partitions a part of the accommodating recess, and is provided with a thick portion. According to the above aspect, since a thick portion is provided between the engaging claw and the accommodating recess, the radial thickness increases by the thickness of the thick portion, and the rigidity of the engaging claw is increased. Thereby, for example, even if the weight member comes into contact with the protruding portion, since the rigidity of the engaging claw is improved, breakage of the engaging claw can be suppressed.

[0010] Another clutch device according to the present invention is a clutch device that transmits or shuts off the rotational driving force of an input shaft to an output shaft, and is housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and a clutch center that is rotationally driven together with the output shaft, and is provided so as to be able to approach or separate from the clutch center, and holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates, and a presser member that can press the input-side rotating plates and the output-side rotating plates, and has a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position by centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, the input-side rotating plates and the output-side rotating plates are brought into pressure contact to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are in the inner position in the radial direction, the pressure contact force between the input-side rotating plates and the output-side rotating plates is released to block the transmission of the rotational driving force of the input shaft to the output shaft, and a centrifugal clutch mechanism, and the centrifugal clutch mechanism includes a holding member that holds the weight members so as to be movable between the inner position in the radial direction and the outer position in the radial direction, a biasing member provided on the holding member that biases the weight members inward in the radial direction, and a pressure contact member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction to bring the input-side rotating plates and the output-side rotating plates into pressure contact, and the holding member includes a main body formed in a ring shape, an engaging claw that projects outward in the radial direction from the outer peripheral edge of the main body and engages with the clutch housing, and a housing recess formed in the main body so as to be recessed in the axial direction of the output shaft and housing the weight members so as to be movable in the radial direction, and the main body includes a wall portion located between the engaging claw and the housing recess in the radial direction, and the radial length of the wall portion is longer than the radial length from the outer peripheral edge of the main body to the outer end of the engaging claw in the radial direction.

[0011] According to another clutch device of the present invention, the main body of the holding member includes a wall portion positioned between the engaging claw and the accommodating recess in the radial direction, and the radial length of the wall portion is longer than the radial length from the outer peripheral edge of the main body to the outer end of the engaging claw in the radial direction. According to the above aspect, since the wall portion is relatively thick, the rigidity of the engaging claw is high. Thereby, for example, even if the weight member contacts the wall portion, since the rigidity of the engaging claw is improved, breakage of the engaging claw can be suppressed.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a clutch device in which breakage of the engaging claw is suppressed.

Brief Description of the Drawings

[0013]

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MODE FOR CARRYING OUT THE INVENTION

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

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

[0016] In the following description, the direction in which the pressure member 70 of the clutch device 10 approaches and separates from the clutch center 40 is defined as direction D, the direction in which the pressure member 70 approaches the clutch center 40 is defined as the first direction D1, and the direction in which the pressure member 70 separates from the clutch center 40 is defined as the second direction D2. Further, the circumferential direction (i.e., the rotational direction) of the clutch center 40 and the pressure member 70 is defined as the circumferential direction S, and the direction from one center-side cam portion 60 to the other center-side cam portion 60 (the direction from one pressure-side cam portion 90 to the other pressure-side cam portion 90) with respect to the circumferential direction S is defined as the first circumferential direction S1 (see FIG. 2), and the direction from the other center-side cam portion 60 to the one center-side cam portion 60 (the direction from the other pressure-side cam portion 90 to the one pressure-side cam portion 90) is defined as the second circumferential direction S2 (see FIG. 2). Further, the radial direction of the output shaft 15 is defined as the radial direction M, the direction away from the output shaft 15 is defined as the outer side M1 (see FIG. 20), and the direction toward the output shaft 15 is defined as the inner side M2 (see FIG. 20). In the present embodiment, the axial direction of the output shaft 15 is the same as direction D. Further, the pressure member 70 and the clutch center 40 rotate in the first circumferential direction S1 (i.e., the direction from the center-side assist cam surface 60A of one center-side cam portion 60 to the center-side slipper cam surface 60S). However, the above directions are merely defined for convenience of explanation and do not limit the installation mode of the clutch device 10 in any way, nor do they limit the present invention in any way.

[0017] As shown in FIG. 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 member 70, a stopper plate 100, a centrifugal clutch mechanism 120, and an auxiliary clutch plate 180.

[0018] As shown in FIG. 1, the output shaft 15 is a shaft body formed in a hollow shape. One end of the output shaft 15 rotatably supports an input gear 35 and a 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 transmission (not shown) of a motorcycle.

[0019] As shown in FIG. 1, the output shaft 15 includes a main body portion 15A extending in the direction D. The main body portion 15A has an oil flow path 15H through which clutch oil circulates inside. The oil flow path 15H is formed between a sleeve 16C externally fitted to a push rod 16A, which will be described later, and the main body portion 15A. The clutch oil circulates inside the output shaft 15, that is, inside the oil flow path 15H of the main body portion 15A.

[0020] As shown in Fig. 1, an oil flow path 15H of an output shaft 15 is provided with a push rod 16A and a push member 16B provided adjacent to the push rod 16A. The push rod 16A and the push member 16B are slidably provided within a sleeve 16C. One end (the left end in the figure) of the push rod 16A is connected to a clutch operation lever (not shown) of a motorcycle, and slides within the sleeve 16C by the operation of the clutch operation lever to press the push member 16B in a second direction D2. A part of the push member 16B protrudes outward (here, in the second direction D2) of the output shaft 15 and is connected to a release bearing 18 provided on a pressure member 70. The sleeve 16C and the push member 16B are formed thinner than the inner diameter of a main body portion 15A, and the flowability of clutch oil is ensured within the oil flow path 15H.

[0021] The clutch housing 30 is formed by aluminum die casting. The clutch housing 30 is formed in a bottomed cylindrical shape. As shown in Fig. 1, the clutch housing 30 has a bottom wall 31 formed in a substantially circular shape and a side wall 33 extending in the second direction D2 from an edge of the bottom wall 31. The clutch housing 30 holds a plurality of input-side rotating plates 20.

[0022] As shown in Fig. 1, an input gear 35 is provided on the bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by a rivet 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates by the rotational drive of an input shaft of an engine. The input gear 35 rotates integrally with the clutch housing 30 independently of the output shaft 15.

[0023] The input-side rotating plate 20 is rotationally driven by the rotational drive of the input shaft. As shown in FIG. 1, the input-side rotating plate 20 is held on the inner peripheral surface of the side wall 33 of the clutch housing 30. The input-side rotating plate 20 is held in the clutch housing 30 by spline fitting. The input-side rotating plate 20 is provided so as to be displaceable along the axial direction (i.e., direction D) of the clutch housing 30. The input-side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0024] The input-side rotating plate 20 is a member that is pressed against the output-side rotating plate 22. The input-side rotating plate 20 is formed in an annular shape. The input-side rotating plate 20 is formed by aluminum die casting. Friction materials (not shown) made of a plurality of pieces of paper are attached to the front and back surfaces of the input-side rotating plate 20. Grooves with a depth of several hundred μm for holding clutch oil are formed between the friction materials.

[0025] As shown in FIG. 1, the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is arranged concentrically with the clutch housing 30. The clutch center 40 holds a plurality of output-side rotating plates 22. The output-side rotating plates 22 are alternately arranged with the input-side rotating plate 20 in the direction D. The clutch center 40 is rotationally driven together with the output shaft 15. The clutch center 40 includes a first clutch center 41 and a second clutch center 51. The first clutch center 41 and the second clutch center 51 are assembled to each other. The second clutch center 51 is located on the outer side M1 in the radial direction M of the first clutch center 41. The second clutch center 51 fits over the first clutch center 41.

[0026] As shown in FIG. 2, the first clutch center 41 includes an output shaft holding portion 42, an annular base wall 43 located on the outer side M1 in the radial direction M of the output shaft holding portion 42, and a plurality of center-side cam portions 60.

[0027] As shown in FIG. 1, the output shaft holding portion 42 is connected to the output shaft 15. As shown in FIG. 2, the output shaft holding portion 42 is formed in a cylindrical shape. An insertion hole 45 into which the output shaft 15 is inserted and spline-fitted is formed in the output shaft holding portion 42. The insertion hole 45 is formed so as to penetrate the output shaft holding portion 42. A plurality of fitting teeth 47 extending in the axial direction (i.e., direction D) of the output shaft 15 are formed on the inner wall 45A that partitions the insertion hole 45 in the output shaft holding portion 42. The fitting teeth 47 are fitted to the output shaft 15.

[0028] The center side cam portion 60 is formed in a trapezoidal shape having a cam surface that is an inclined surface constituting an assist & slipper (registered trademark) mechanism that generates an assist torque that is a force for increasing the pressing force (contact pressure) between the input side rotating plate 20 and the output side rotating plate 22 or a slipper torque that is a force for reducing the pressing force (contact pressure) between the input side rotating plate 20 and the output side rotating plate 22 and causing a transition to a semi-clutch state. The semi-clutch state is a state between a state where the clutch is completely engaged (i.e., a state where the input side rotating plate 20 and the output side rotating plate 22 are in pressure contact with each other) and a state where the clutch is completely disengaged (i.e., a state where the input side rotating plate 20 and the output side rotating plate 22 are separated from each other). As shown in FIG. 2, the center side cam portion 60 is formed so as to project in the second direction D2 from the surface 43D2 on the second direction D2 side of the base wall 43. The center side cam portions 60 are arranged at equal intervals in the circumferential direction S of the first clutch center 41. In the present embodiment, the first clutch center 41 has three center side cam portions 60, but the number of center side cam portions 60 is not limited to three.

[0029] As shown in FIG. 2, the center-side cam portion 60 is located outside M1 in the radial direction M of the output shaft holding portion 42. The center-side cam portion 60 has a center-side assist cam surface 60A (see also FIG. 3) and a center-side slipper cam surface 60S. When the center-side assist cam surface 60A rotates relative to the pressure member 70, such as when accelerating, it is configured to generate a force (here, the first direction D1) in the direction toward the clutch center 40 for the pressure member 70 in order to increase the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22. In the present embodiment, when the above force is generated, the position of the pressure member 70 relative to the clutch center 40 does not change, and it is not necessary for the pressure member 70 to physically approach the clutch center 40. Note that the pressure member 70 may physically displace relative to the clutch center 40. The center-side slipper cam surface 60S is configured to separate the pressure member 70 from the clutch center 40 in order to decrease the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22 when it rotates relative to the pressure member 70, such as when decelerating. In the center-side cam portions 60 adjacent in the circumferential direction S, the center-side assist cam surface 60A of one center-side cam portion 60L and the center-side slipper cam surface 60S of the other center-side cam portion 60M are arranged to face each other in the circumferential direction S.

[0030] As shown in FIG. 2, the first clutch center 41 includes a plurality (three in the present embodiment) of boss portions 62. The boss portion 62 is a member that indirectly holds the pressure member 70. The plurality of boss portions 62 are arranged at equal intervals in the circumferential direction S. The boss portion 62 is formed in a cylindrical shape. The boss portion 62 is located outside M1 in the radial direction M from the output shaft holding portion 42. The boss portion 62 extends toward the pressure member 70 (i.e., in the second direction D2). The boss portion 62 is provided on the center-side cam portion 60. The boss portion 62 is provided between the center-side assist cam surface 60A and the center-side slipper cam surface 60S in the circumferential direction S. A screw hole 62H into which a bolt 28 (see FIG. 1) is inserted is formed in the boss portion 62. The screw hole 62H extends in the axial direction (i.e., direction D) of the clutch center 40.

[0031] As shown in FIGS. 2 and 3, the first clutch center 41 has a center-side cam hole 43H that penetrates a part of the base wall 43. The center-side cam hole 43H penetrates the base wall 43 in the direction D. The center-side cam hole 43H extends in the radial direction M from the side of the output shaft holding portion 42. The center-side cam hole 43H is positioned between adjacent center-side cam portions 60 in the circumferential direction S. When viewed from the axial direction of the clutch center 40, a part of the center-side assist cam surface 60A overlaps with a part of the center-side cam hole 43H.

[0032] As shown in FIG. 2, the first clutch center 41 has a plurality of engagement grooves 49. The engagement grooves 49 are formed on the outer peripheral surface of the base wall 43. The engagement grooves 49 are recessed from the outer peripheral surface of the base wall 43 toward the inner side M2 in the radial direction M.

[0033] As shown in FIG. 4, the second clutch center 51 includes an annular outer peripheral wall 52, a flange 68 that extends from the outer peripheral wall 52 to the outer side M1 in the radial direction M, and a center-side fitting portion 54. The second clutch center 51 holds a plurality of output-side rotating plates 22 that are alternately arranged with the input-side rotating plate 20 in the direction D. The flange 68 is configured to be able to press the input-side rotating plate 20 and the output-side rotating plates 22.

[0034] As shown in FIG. 4, a spline fitting portion 56 is provided on the outer peripheral surface of the outer peripheral wall 52. The spline fitting portion 56 includes a plurality of center-side fitting teeth 57 that extend in the axial direction (i.e., direction D) of the second clutch center 51 along the outer peripheral surface of the outer peripheral wall 52, a plurality of spline grooves 58 that are formed between adjacent center-side fitting teeth 57 and extend in the axial direction (i.e., direction D) of the second clutch center 51, and an oil discharge hole 59. The center-side fitting teeth 57 hold the output-side rotating plate 22. The plurality of center-side fitting teeth 57 are arranged in the circumferential direction S. The plurality of center-side fitting teeth 57 are formed at equal intervals in the circumferential direction S. The plurality of center-side fitting teeth 57 are formed in the same shape. The center-side fitting teeth 57 project outward in the radial direction M from the outer peripheral surface of the outer peripheral wall 52. The oil discharge hole 59 is formed to penetrate the outer peripheral wall 52 in the radial direction M. The oil discharge hole 59 is formed between adjacent center-side fitting teeth 57. That is, the oil discharge hole 59 is formed in the spline groove 58. The oil discharge hole 59 is formed in the center-side fitting portion 54. The oil discharge hole 59 communicates the inside and the outside of the second clutch center 51. The oil discharge hole 59 is a hole that discharges clutch oil or the like 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 oil discharge hole 59 is supplied to the input-side rotating plate 20 and the output-side rotating plate 22 located on the outer side M1 in the radial direction M of the oil discharge hole 59.

[0035] The output-side rotating plate 22 is held by the spline fitting portion 56 and the pressure member 70 of the second clutch center 51. A part of the output-side rotating plate 22 is held by spline fitting with the center-side fitting teeth 57 and the spline grooves 58 of the second clutch center 51. Another part of the output-side rotating plate 22 is held by the pressure-side fitting teeth 87 (see FIG. 6) of the pressure member 70 described later. The output-side rotating plate 22 is provided so as to be displaceable along the axial direction (i.e., direction D) of the 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., direction D) of the pressure member 70. The output-side rotating plate 22 is provided so as to be rotatable integrally with the pressure member 70.

[0036] The output-side rotating plate 22 is a member that is pressed against the input-side rotating plate 20. The output-side rotating plate 22 is formed in an annular shape. The output-side rotating plate 22 is formed by punching and shaping a thin plate material made of SPCC material into an annular shape. Note that the friction material provided on the input-side rotating plate 20 may be provided on the output-side rotating plate 22 instead of the input-side rotating plate 20, or may be provided on each of the input-side rotating plate 20 and the output-side rotating plate 22.

[0037] As shown in FIG. 4, the center-side fitting portion 54 is formed on the inner peripheral surface of the outer peripheral wall 52. The center-side fitting portion 54 is configured to be slidably externally fitted to a pressure-side fitting portion 88 (see FIG. 6) described later. The inner diameter of the center-side fitting portion 54 is formed with a fitting tolerance that allows the flow of clutch oil flowing out from the tip portion 15T (see FIG. 1) of the output shaft 15 with respect to the pressure-side fitting portion 88. That is, a gap is formed between the center-side fitting portion 54 and the pressure-side fitting portion 88.

[0038] As shown in FIGS. 4 and 5, the second clutch center 51 has a plurality of engaging protrusions 55. The engaging protrusions 55 engage with the engaging grooves 49 (see FIG. 2) of the first clutch center 41. The engaging protrusions 55 are formed on the inner peripheral surface of the outer peripheral wall 52. The engaging protrusions 55 project from the inner peripheral surface of the outer peripheral wall 52 toward the inner side M2 in the radial direction M.

[0039] As shown in FIG. 1, the pressure member 70 is provided so as to be able to approach or separate from the clutch center 40. The pressure member 70 is provided so as to be relatively rotatable with respect to the clutch center 40. The pressure member 70 is configured to be able to press the input-side rotating plate 20 and the output-side rotating plate 22. The pressure member 70 is arranged concentrically with the clutch center 40 and the clutch housing 30. The pressure member 70 is fitted inside the second clutch center 51. Thereby, the positioning of the pressure member 70 in the radial direction M is achieved. The pressure member 70 is provided so as to be slidable with respect to the first clutch center 41 and the second clutch center 51 in the direction D. The pressure member 70, the first clutch center 41, and the second clutch center 51 are configured to be relatively rotatable with respect to each other in the circumferential direction S. As shown in FIG. 6, the pressure member 70 has a main body 72 and a flange 98 that is connected to the outer peripheral edge on the second direction D2 side of the main body 72 and extends to the outside M1 in the radial direction M. The main body 72 protrudes in the first direction D1 more than the flange 98. The flange 98 is located at the outer diameter end of the pressure member 70. The flange 98 is located on the outside M1 in the radial direction M more than the cylindrical portion 80 (also refer to FIG. 7) described later. The pressure member 70 holds at least a part of the plurality of output-side rotating plates 22 arranged alternately with the input-side rotating plate 20. The flange 98 is configured to be able to press the input-side rotating plate 20 and the output-side rotating plate 22.

[0040] As shown in FIG. 6, the main body 72 includes a cylindrical portion 80, a plurality of pressure-side cam portions 90, a pressure-side fitting portion 88, and a spring accommodating portion 84 (refer to FIG. 7).

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

[0042] As shown in FIG. 6, the pressure-side cam portion 90 is formed in a trapezoidal shape having a cam surface formed of an inclined surface that constitutes an assist & slipper (registered trademark) mechanism that slides on the center-side cam portion 60 to generate assist torque or slipper torque. The pressure-side cam portion 90 is formed so as to protrude in the first direction D1 from the flange 98. The pressure-side cam portions 90 are arranged at equal intervals in the circumferential direction S of the pressure member 70. In the present embodiment, the pressure member 70 has three pressure-side cam portions 90, but the number of pressure-side cam portions 90 is not limited to three.

[0043] As shown in FIG. 6, the pressure-side cam portion 90 is located on the outer side M1 in the radial direction M from the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also FIG. 7) and a pressure-side slipper cam surface 90S. The pressure-side assist cam surface 90A is configured to be capable of contacting the center-side assist cam surface 60A. The pressure-side assist cam surface 90A is configured to generate a force in the direction from the pressure member 70 toward the clutch center 40 (here, the first direction D1) in order to increase the pressing force (contact pressure) between the input-side rotating plate 20 and the output-side rotating plate 22 when the clutch center 40 rotates relative to it, such as when accelerating. The pressure-side slipper cam surface 90S is configured to be capable of contacting the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to separate the pressure member 70 from the clutch center 40 in order to decrease the pressing force (contact pressure) between the input-side rotating plate 20 and the output-side rotating plate 22 when the clutch center 40 rotates relative to it, such as when decelerating. In the pressure-side cam portions 90 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 90M are arranged to face each other in the circumferential direction S.

[0044] Here, the operations of the center-side cam portion 60 and the pressure-side cam portion 90 will be described. When the engine speed increases and the rotational driving force input to the input gear 35 and the clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, as shown in FIG. 8A, a rotational force in the first circumferential direction S1 is applied to the pressure member 70. Therefore, due to the operations of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A, a force in the first direction D1 is generated on the pressure member 70, increasing the pressing contact force between the input-side rotating plate 20 and the output-side rotating plate 22.

[0045] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational speeds of the input gear 35 and the clutch housing 30 and a back torque occurs, as shown in FIG. 8B, a rotational force in the first circumferential direction S1 is applied to the clutch center 40. Therefore, due to the operations of the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S, the pressure member 70 is moved in the second direction D2 to release the pressing contact force between the input-side rotating plate 20 and the output-side rotating plate 22. Thereby, problems with respect to the engine and the transmission due to the back torque can be avoided.

[0046] As shown in FIG. 6, the pressure-side fitting portion 88 is located on the outer side M1 in the radial direction M from the pressure-side cam portion 90. The pressure-side fitting portion 88 is located on the second direction D2 side from the pressure-side cam portion 90. The pressure-side fitting portion 88 is configured to be slidably fitted inside the center-side fitting portion 54 (see FIG. 4).

[0047] As shown in FIGS. 6 and 7, the pressure member 70 has a pressure-side cam hole 83H that penetrates a part of the main body 72 and the flange 98. The pressure-side cam hole 83H is located on the outer side M1 in the radial direction M from the cylindrical portion 80. The pressure-side cam hole 83H extends in the radial direction M from the side of the cylindrical portion 80 to the outer side M1 in the radial direction M 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 the adjacent pressure-side cam portions 90. When viewed from the axial direction of the pressure member 70, a part of the pressure-side assist cam surface 90A overlaps with a part of the pressure-side cam hole 83H. The boss portion 62 (see FIG. 2) of the first clutch center 41 is inserted into the pressure-side cam hole 83H. The boss portion 62 penetrates the pressure-side cam hole 83H.

[0048] As shown in FIG. 6, the pressure member 70 includes a plurality of pressure-side fitting teeth 87 disposed on the flange 98. The pressure-side fitting teeth 87 hold at least a part of the output-side rotating plate 22. The pressure-side fitting teeth 87 project from the flange 98 in the first direction D1. The pressure-side fitting teeth 87 are located on the outer side M1 in the radial direction M from the cylindrical portion 80. The pressure-side fitting teeth 87 are located on the outer side M1 in the radial direction M from the pressure-side cam portion 90. The pressure-side fitting teeth 87 are located on the outer side M1 in the radial direction M from 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 part 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 interval in the direction D (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 position PI on the inner side M2 in the radial direction M.

[0049] As shown in FIG. 7, the spring housing portion 84 is formed in the pressure-side cam portion 90. The spring housing portion 84 is located on the outer side M1 in the radial direction M with respect to the cylindrical portion 80. The spring housing portion 84 is formed so as to be recessed from the second direction D2 toward the first direction D1. The spring housing portion 84 is formed in a circular shape. The spring housing portion 84 houses the clutch spring 25.

[0050] As shown in FIG. 1, the clutch spring 25 is housed in the spring housing portion 84. The end portion 25D1 in the first direction D1 of the clutch spring 25 is in contact with the pressure member 70. The end portion 25D2 in the second direction D2 of the clutch spring 25 is in contact with the stopper plate 100. The clutch spring 25 biases the pressure member 70 toward the clutch center 40 (i.e., in the first direction D1). The clutch spring 25 is, for example, a coil spring formed by spirally winding spring steel. The clutch spring 25 extends in the direction D.

[0051] As shown in FIG. 1, the centrifugal clutch mechanism 120 is provided within the clutch housing 30. The centrifugal clutch mechanism 120 is provided on the first direction D1 side with respect to 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 FIG. 9A, the centrifugal clutch mechanism 120 includes a plurality of weight members 130, a holding member 140, a pressing member 150 (see FIG. 1), a spring 160 (also see FIG. 9B), and a contact member 170 (see FIG. 1). The centrifugal clutch mechanism 120 is configured such that when the weight member 130 is at the position PO on the outer side M1 in the radial direction M (see FIGS. 1 and 21), the input-side rotating plate 20 and the output-side rotating plate 22 are pressed against each other to enable transmission of the rotational driving force of the input shaft to the output shaft 15. The centrifugal clutch mechanism 120 is configured such that when the weight member 130 is at the position PI on the inner side M2 in the radial direction M (see FIG. 20), the pressing force between the input-side rotating plate 20 and the output-side rotating plate 22 is released to block transmission of the rotational driving force of the input shaft to the output shaft 15. The centrifugal clutch mechanism 120 is configured to be able to press the auxiliary clutch plate 180 (see FIG. 1).

[0052] As shown in FIG. 9B, the holding member 140 movably holds the weight member 130 between the position PI on the inner side M2 in the radial direction M and the position PO on the outer side M1 in the radial direction M (see FIG. 18). 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 main body 141, a plurality of engaging claws 143, a plurality of accommodating recesses 145, and a pressing portion 149 (see FIG. 1).

[0053] As shown in FIG. 10, the main body 141 is formed in a ring shape. As shown in FIG. 12A, the main body 141 includes a thick portion 141T including a wall portion 141A and a protruding portion 141B. The wall portion 141A is located between the engagement claw 143 and the accommodation recess 145 with respect to the radial direction M. The protruding portion 141B protrudes from the wall portion 141A toward the inner side M2 in the radial direction M. The protruding portion 141B partitions a part of the accommodation recess 145. The end portion 141BX on the inner side M2 in the radial direction M of the protruding portion 141B is located on the inner side M2 in the radial direction M rather than the end portion 145X on the outer side M1 in the radial direction M of the accommodation recess 145. As shown in FIG. 9B, the protruding portion 141B is located between a first spring 161 and a second spring 162, which will be described later, with respect to the circumferential direction S. Note that the two-dot chain line 141EL in FIG. 12B indicates the outer peripheral edge 141E. The two-dot chain line 145XL in FIG. 12B indicates a straight line that passes through the end portion 145X on the outer side M1 in the radial direction M of the accommodation recess 145 and is orthogonal to the radial direction M when viewed from the axial direction of the output shaft 15. The two-dot chain line 141BXL in FIG. 12B indicates a straight line that passes through the end portion 141BX on the inner side M2 in the radial direction M of the protruding portion 141B and is orthogonal to the radial direction M when viewed from the axial direction of the output shaft 15.

[0054] As shown in FIG. 10, the engagement claw 143 protrudes from the outer peripheral edge 141E of the main body 141 toward the outer side M1 in the radial direction M. The engagement claw 143 is integrally formed with the main body 141. The engagement claw 143 engages with the clutch housing 30 (see FIG. 1). The plurality of engagement claws 143 are arranged in the circumferential direction S. As shown in FIG. 12A, the engagement claw 143 has a head portion 143A and a root portion 143B located radially inward of the head portion 143A. The length LA in the circumferential direction S of the head portion 143A is longer than the length LB in the circumferential direction S of the root portion 143B.

[0055] As shown in FIG. 1, the accommodation recess 145 is formed in the main body 141 so as to be recessed in the axial direction (i.e., direction D) of the output shaft 15. The accommodation recess 145 is recessed in the first direction D1. The accommodation recess 145 accommodates the weight member 130 so as to be movable in the radial direction M. The plurality of accommodation recesses 145 are arranged in the circumferential direction S. As shown in FIGS. 10 and 11, the accommodation recess 145 is provided with a sliding surface 145M on which the weight member 130 slides when the weight member 130 moves in the radial direction M. An accommodation groove 146 for accommodating a part of the spring 160 is formed in the accommodation recess 145. The accommodation groove 146 extends in the radial direction M. The accommodation groove 146 includes a first accommodation groove 146A for accommodating the first spring 161 and a second accommodation groove 146B for accommodating the second spring 162, which will be described later. The first accommodation groove 146A is located on the first circumferential direction S1 side of the protrusion 141B. The second accommodation groove 146B is located on the second circumferential direction S2 side of the protrusion 141B. One end of each of the first spring 161 and the second spring 162 abuts against the end 145X on the outer side M1 in the radial direction M of the accommodation recess 145. As shown in FIG. 19, the accommodation recess 145 is provided with a pressing surface 145H that is pressed by the weight member 130 when the weight member 130 is at the position PO on the outer side M1 in the radial direction M. A stress in the outer side M1 in the radial direction M is applied to the pressing surface 145H from the weight member 130. The engaging claw 143 and the pressing surface 145H are arranged offset in the circumferential direction S. Here, the engaging claw 143 is arranged between a pair of pressing surfaces 145H in the circumferential direction S. Note that a through hole penetrating the main body 141 in the axial direction (i.e., direction D) of the output shaft 15 may be formed in the accommodation recess 145. In this case, the clutch oil flowing outside the holding member 140 flows into the accommodation recess 145 through the through hole.

[0056] As shown in FIG. 12A, the length L1 in the circumferential direction S of the protruding portion 141B is equal to or greater than the length L2 in the circumferential direction S of the engaging claw 143. The radial length L3 from the outer peripheral edge 141E of the main body 141 to the end 141BX on the inner side M2 in the radial direction M of the protruding portion 141B is longer than the radial length L4 from the outer peripheral edge 141E of the main body 141 to the end 143X on the outer side M1 in the radial direction M of the engaging claw 143. The end 141BL in the first circumferential direction S1 of the protruding portion 141B is located closer to the first circumferential direction S1 side than the end 143AL in the first circumferential direction S1 of the engaging claw 143. Here, the end 143AL in the first circumferential direction S1 of the engaging claw 143 is the end in the first circumferential direction S1 of the head 143A. The end 141BR in the second circumferential direction S2 of the protruding portion 141B is located closer to the second circumferential direction S2 side than the end 143AR in the second circumferential direction S2 of the engaging claw 143. Here, the end 143AR in the second circumferential direction S2 of the engaging claw 143 is the end in the second circumferential direction S2 of the head 143A. Also, the end 141BL in the first circumferential direction S1 of the protruding portion 141B is located closer to the first circumferential direction S1 side than the end 143BL in the first circumferential direction S1 of the root portion 143B. The end 141BR in the second circumferential direction S2 of the protruding portion 141B is located closer to the second circumferential direction S2 side than the end 143BR in the second circumferential direction S2 of the root portion 143B. The surfaces on the side of the pressing member 150 of the wall portion 141A, the protruding portion 141B, and the engaging claw 143 are formed flush. Note that the two-dot chain line 143XL in FIG. 12B indicates a straight line that passes through the end 143X on the outer side M1 in the radial direction M of the engaging claw 143 and is orthogonal to the radial direction M when viewed from the axial direction of the output shaft 15. The two-dot chain line 141BLL in FIG. 12B indicates a straight line that passes through the end 141BL in the first circumferential direction S1 of the protruding portion 141B and is parallel to the radial direction M when viewed from the axial direction of the output shaft 15. The two-dot chain line 143ALL in FIG. 12B indicates a straight line that passes through the end 143AL in the first circumferential direction S1 of the engaging claw 143 and is parallel to the radial direction M when viewed from the axial direction of the output shaft 15. The two-dot chain line 143BLL in FIG. 12B indicates a straight line that passes through the end 143BL in the first circumferential direction S1 of the root portion 143B and is parallel to the radial direction M when viewed from the axial direction of the output shaft 15. The two-dot chain line 141BRL in FIG. 12B indicates a straight line that passes through the end 141BR in the second circumferential direction S2 of the protruding portion 141B and is parallel to the radial direction M when viewed from the axial direction of the output shaft 15.The two-dot chain line 143ARL in Fig. 12B indicates a straight line passing through the end 143AR of the engaging claw 143 in the second circumferential direction S2 and parallel to the radial direction M as viewed from the axial direction of the output shaft 15. The two-dot chain line 143BRL in Fig. 12B indicates a straight line passing through the end 143BR of the base portion 143B in the second circumferential direction S2 and parallel to the radial direction M as viewed from the axial direction of the output shaft 15.

[0057] As shown in Fig. 9B, the plurality of weight members 130 are arranged in the circumferential direction S. The weight members 130 are configured to be movable from the position PI on the inner side M2 of the radial direction M to the outer side position by the centrifugal force accompanying the rotation of the clutch housing 30. The weight members 130 are configured to be able to press the pressing member 150 in the second direction D2. As shown in Fig. 20, the weight members 130 are held at the position PI on the inner side M2 of the radial direction M by the spring 160 (see Fig. 9B) when no centrifugal force is applied. As shown in Fig. 21, when the centrifugal force is applied, the weight members 130 move toward the outer side M1 of the radial direction M against the biasing force of the spring 160 and move to the position PO on the outer side M1 of the radial direction M. At this time, as shown in Fig. 19, the weight members 130 press the pressing surface 145H of the housing recess 145, but the weight members 130 do not contact the protruding portion 141B of the holding member 140. The weight members 130 are housed in the housing recess 145 of the holding member 140. As shown in Fig. 15, the weight members 130 include a biasing member holding portion 131, a first plane 133 provided on one side of the circumferential direction S with respect to the biasing member holding portion 131, a second plane 135 provided on the other side of the circumferential direction S with respect to the biasing member holding portion 131, and a weight side inclined surface 130F (see Fig. 13) located on the side opposite to the first plane 133 and the second plane 135 with respect to the axial direction (i.e., direction D) of the output shaft 15. The weight side inclined surface 130F is an example of a weight side sliding portion.

[0058] The biasing member holding portion 131 holds the spring 160. As shown in FIG. 15, the biasing member holding portion 131 is a concave groove that recesses from the first direction D1 toward the second direction D2 and from the outer side M1 to the inner side M2 in the radial direction M. The biasing member holding portion 131 includes a holding wall 132 that holds the end portion of the spring 160 on the inner side M2 in the radial direction M. In the present embodiment, the biasing member holding portion 131 includes a first biasing member holding portion 131A that holds the first spring 161 described later, and a second biasing member holding portion 131B that holds the second spring 162 described later.

[0059] As shown in FIGS. 15 and 16, the first plane 133 is provided on the first circumferential direction S1 side of the biasing member holding portion 131. More specifically, the first plane 133 is provided on the first circumferential direction S1 side of the first biasing member holding portion 131A. The first plane 133 is provided side by side in the circumferential direction with the first biasing member holding portion 131A. The second plane 135 is provided on the second circumferential direction S2 side of the biasing member holding portion 131. More specifically, the second plane 135 is provided on the second circumferential direction S2 side of the second biasing member holding portion 131B. The second plane 135 is provided side by side in the circumferential direction with the second biasing member holding portion 131B. As shown in FIG. 17, the first plane 133 and the second plane 135 are orthogonal to the axial direction (i.e., direction D) of the output shaft 15. The first plane 133 and the second plane 135 are formed flush. The first plane 133 and the second plane 135 are provided slidably with respect to the holding member 140. More specifically, the first plane 133 and the second plane 135 are provided slidably with respect to the sliding surface 145M of the housing recess 145. As shown in FIG. 16, the end portion 133A on the inner side M2 in the radial direction M of the first plane 133 and the end portion 135A on the inner side M2 in the radial direction M of the second plane 135 are located on the inner side M2 in the radial direction M with respect to the holding wall 132.

[0060] As shown in FIG. 15, the weight member 130 includes a third plane 137. The third plane 137 is located between the first plane 133 and the second plane 135 with respect to the circumferential direction S. The third plane 137 is located between the first biasing member holding portion 131A and the second biasing member holding portion 131B with respect to the circumferential direction S. The third plane 137 may be provided slidably with respect to the holding member 140. The third plane 137 may be formed flush with the first plane 133 and the second plane 135.

[0061] The weight side inclined surface 130F is provided so as to be contactable with the pressing member 150. As shown in FIG. 17, the weight side inclined surface 130F is inclined with respect to the axial direction (i.e., direction D) of the output shaft 15. The weight side inclined surface 130F is inclined so as to face the first direction D1 from the inner side M2 in the radial direction M toward the outer side M1 in the radial direction M. The weight side inclined surface 130F is configured to be slidable with respect to a pressing side inclined surface 150F (see FIG. 20) of the pressing member 150 described later.

[0062] As shown in FIG. 17, the end portion 133B on the outer side M1 in the radial direction M of the first plane 133 and the end portion 135B on the outer side M1 in the radial direction M of the second plane 135 are located on the outer side M1 in the radial direction M rather than the end portion 130FA on the inner side M2 in the radial direction M of the weight side inclined surface 130F. The end portion 133A on the inner side M2 in the radial direction M of the first plane 133 and the end portion 135A on the inner side M2 in the radial direction M of the second plane 135 are located on the inner side M2 in the radial direction M rather than the end portion 130FA on the inner side M2 in the radial direction M of the weight side inclined surface 130F. The length L5 in the radial direction M of the first plane 133 and the second plane 135 is longer than the length L6 in the radial direction M of the weight side inclined surface 130F. The total area of the first plane 133 and the second plane 135 is larger than the area of the weight side inclined surface 130F. The length L7 (see FIG. 16) in the circumferential direction S from the end portion 133S1 in the first circumferential direction S1 of the first plane 133 to the end portion 135S2 in the second circumferential direction S2 of the second plane 135 is longer than the length L8 (see FIG. 14) in the circumferential direction S of the weight side inclined surface 130F.

[0063] As shown in FIG. 9B, the spring 160 is disposed outside M1 in the radial direction M of the weight member 130. The spring 160 is an example of a biasing member. The spring 160 is provided on the holding member 140. The spring 160 is housed in the housing recess 145 of the holding member 140. More specifically, a part of the spring 160 is housed in the housing groove 146 (see FIG. 10). A part of the spring 160 is located inside the weight member 130. That is, a part of the spring 160 is located within the biasing member holding portion 131. The spring 160 biases the weight member 130 toward the inner side M2 in the radial direction M. 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 housing recess 145. The first spring 161 and the second spring 162 bias the weight member 130 toward the inner side M2 in the radial direction M. The first spring 161 and the second spring 162 are provided between the first plane 133 and the second plane 135 with respect to the circumferential direction S.

[0064] As shown in FIG. 1, the contact member 170 is disposed between the holding member 140 and the pressure contact member 150. The contact member 170 is disposed on the opposite side of the holding member 140 with the weight member 130 interposed therebetween in the axial direction (here, direction D) of the output shaft 15. As shown in FIG. 9A, the contact member 170 is formed in a disc shape. The contact member 170 is fixed to the holding member 140. More specifically, the contact member 170 is fixed to the holding member 140 by fastening a bolt 172 to a bolt hole 140H (see FIG. 9B) formed in the holding member 140. Note that the means for fixing the contact member 170 to the holding member 140 is not limited to the bolt 172. Instead of the bolt 172, for example, the contact member 170 may be fixed to the holding member 140 by other fixing means such as a rivet. The contact member 170 contacts the weight member 130. The contact member 170 is a member that suppresses the movement of the weight member 130 in the second direction D2. A plurality of openings 170H arranged in the circumferential direction S are formed in the contact member 170. The weight side inclined surface 130F of the weight member 130 is exposed to the outside from the opening 170H.

[0065] The clamping member 150 is configured to move in the axial direction of the output shaft 15 (here, the second direction D2) when the weight member 130 moves from the position PI on the inner side M2 in the radial direction M to the position PO on the outer side M1, so that the input-side rotating plate 20 and the output-side rotating plate 22 can be clamped. The clamping member 150 is formed in an annular shape. As shown in FIG. 1, the clamping member 150 has a clamping-side inclined surface 150F and a pressing surface 150P. The clamping-side inclined surface 150F is an example of a clamping-side sliding portion. The clamping-side inclined surface 150F is provided so as to be in contact with the weight member 130. The clamping-side inclined surface 150F is inclined with respect to the axial direction of the output shaft 15 (i.e., the direction D). The clamping-side inclined surface 150F is inclined so as to face the first direction D1 from the inner side M2 in the radial direction M toward the outer side M1 in the radial direction M. The clamping-side inclined surface 150F is configured to be slidable with respect to the weight-side inclined surface 130F of the weight member 130. As shown in FIG. 21, in a cross-sectional view in a plane including the axial direction of the output shaft 15 (i.e., the direction D) and the radial direction M, a straight line CL1 passing through the center 150FC in the radial direction M of the clamping-side inclined surface 150F and parallel to the axial direction of the output shaft 15 (i.e., the direction D) passes through the first plane 133 and the second plane 135 when the weight member 130 is located on the outer side M1 in the radial direction M. A plurality of engaging protrusions 153 are provided over the circumferential direction S for each weight member 130. The engaging protrusions 153 overlap with the engaging claws 143 of the holding member 140. The engaging protrusions 153 engage with the clutch housing 30. The holding member 140 and the clamping member 150 are held in the clutch housing 30 by spline fitting. The holding member 140 and the clamping member 150 are provided so as to be displaceable along the axial direction of the clutch housing 30 (i.e., the direction D).The holding member 140 and the pressure contact member 150 are provided so as to be rotatable integrally with the clutch housing 30.

[0066] In such a centrifugal clutch mechanism 120, as shown in FIGS. 9A and 20, when no centrifugal force is applied to the weight member 130, the weight member 130 is held at the position P1 on the inner side M2 in the radial direction M, and the pressing force between the input-side rotating plate 20 and the output-side rotating plate 22 is released. On the other hand, as shown in FIGS. 18 and 21, when centrifugal force is applied to the weight member 130, the weight member 130 moves from the position P1 on the inner side M2 in the radial direction M to the position PO on the outer side M1. When the weight member 130 moves in the radial direction M, the weight-side inclined surface 130F of the weight member 130 and the pressure-contact-side inclined surface 150F of the pressure contact member 150 slide, and the first plane 133 and the second plane 135 of the weight member 130 and the sliding surface 145M of the holding member 140 slide. At this time, the pressing surface 150P of the pressure contact member 150 presses the input-side rotating plate 20 and the output-side rotating plate 22 via the flange 68 of the second clutch center 51 to bring them into a pressure-contact state, and the rotational driving force of the input shaft can be transmitted to the output shaft 15. At the same time, the holding member 140 moves in the first direction D1, and the pressing portion 149 (see FIG. 1) of the holding member 140 presses the auxiliary clutch plate 180.

[0067] As shown in FIG. 1, the auxiliary clutch plate 180 is provided in the clutch housing 30. The auxiliary clutch plate 180 is fixed to the output shaft 15. An insertion hole 152H into which the output shaft 15 is inserted and spline-fitted is formed in the auxiliary clutch plate 180. The auxiliary clutch plate 180 is disposed on the first direction D1 side of a part of the centrifugal clutch mechanism 120. The auxiliary clutch plate 180 is adjacent to the first clutch center 41.

[0068] The auxiliary clutch plate 180 is configured to be pressed by the centrifugal clutch mechanism 120 (here, the pressing portion 149 of the holding member 140) when the input-side rotating plate 20 and the output-side rotating plate 22 are in pressure contact (that is, when the weight member 130 of the centrifugal clutch mechanism 120 is located at the position PO on the outer side M1 in the radial direction M), so that the rotational driving force of the input shaft can be transmitted to the output shaft 15. The auxiliary clutch plate 180 is configured to be released from the pressing by the centrifugal clutch mechanism 120 (here, the pressing portion 149 of the holding member 140) when the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22 is released (that is, when the weight member 130 is located at the position PI on the inner side M2 in the radial direction M), and to block the transmission of the rotational driving force of the input shaft to the output shaft 15.

[0069] As shown in FIG. 1, the stopper plate 100 is provided so as to be capable of contacting the pressure member 70. The stopper plate 100 is a member that suppresses the pressure member 70 from separating from the clutch center 40 by a predetermined distance or more in the second direction D2. The stopper plate 100 is fixed to the boss portion 62 of the first clutch center 41 by bolts 28. The pressure member 70 is fixed to the clutch center 40 with the clutch spring 25 disposed in the spring housing portion 84 and the bolts 28 tightened to the boss portion 62 via the stopper plate 100. The stopper plate 100 is formed in a ring shape in plan view.

[0070] As described above, according to the clutch device 10 of the present embodiment, the main body 141 of the holding member 140 includes a wall portion 141A located between the engaging claw 143 and the housing recess 145 with respect to the radial direction M, and a protruding portion 141B that protrudes from the wall portion 141A toward the inner side M2 in the radial direction M and partitions a part of the housing recess 145. According to the above aspect, since the thick portion 141T is provided between the engaging claw 143 and the housing recess 145, the thickness in the radial direction M increases by the amount of the thick portion 141T, and the rigidity of the engaging claw 143 is increased. Thereby, for example, even if the weight member 130 comes into contact with the protruding portion 141B, since the rigidity of the engaging claw 143 is improved, breakage of the engaging claw 143 can be suppressed.

[0071] In the clutch device 10 of the present embodiment, the length L1 in the circumferential direction S of the protruding portion 141B is equal to or greater than the length L2 in the circumferential direction S of the engaging claw 143. According to the above aspect, the rigidity of the engaging claw 143 can be made higher.

[0072] In the clutch device 10 of the present embodiment, the length L3 in the radial direction M from the outer peripheral edge 141E of the main body 141 to the end 141BX on the inner side M2 in the radial direction M of the protruding portion 141B is longer than the length L4 in the radial direction M from the outer peripheral edge 141E of the main body 141 to the end 143X on the outer side M1 in the radial direction M of the engaging claw 143. According to the above aspect, the rigidity of the engaging claw 143 can be made higher.

[0073] In the clutch device 10 of the present embodiment, the protruding portion 141B is positioned between the first spring 161 and the second spring 162 in the circumferential direction S. According to the above aspect, the load from the weight member 130 applied to the engaging claw 143 can be reduced.

[0074] <Second Embodiment> As shown in FIG. 22, the centrifugal clutch mechanism 220 according to the second embodiment includes a plurality of weight members 230, a holding member 240, a pressing member 150, a spring 160 (see FIG. 25), and a cylindrical member 270. The centrifugal clutch mechanism 220 has the same configuration as the centrifugal clutch mechanism 120 according to the first embodiment, except that it has the weight member 230 instead of the weight member 130, has the holding member 240 instead of the holding member 140, and further has the cylindrical member 270.

[0075] As shown in FIGS. 22 and 23, the holding member 240 includes a holding member side guide portion 245 that houses a part of the cylindrical member 270. The holding member side guide portion 245 is formed on a surface 245M of the housing recess 145 that faces the weight member 230. The holding member side guide portion 245 holds the cylindrical member 270 such that a part of the cylindrical member 270 protrudes from the surface 245M of the holding member 240 facing the weight member 230 toward the weight member 230 (i.e., in the second direction D2). The holding member side guide portion 245 guides the movement of the cylindrical member 270 in the radial direction M. The holding member side guide portion 245 is positioned between the first housing groove 146A and the second housing groove 146B in the circumferential direction S. The holding member side guide portion 245 is formed in a rectangular shape in plan view. The holding member side guide portion 245 is configured to restrict the movement of the cylindrical member 270 in the circumferential direction S and to restrict the movement of the cylindrical member 270 in the radial direction M by a predetermined distance or more.

[0076] As shown in FIG. 24, the weight member 230 includes a guide portion 238 that houses a part of the cylindrical member 270. The guide portion 238 is formed on a surface (here, the third plane 137) facing the holding member 240. The guide portion 238 holds the cylindrical member 270 such that a part of the cylindrical member 270 protrudes from the surface (here, the third plane 137) facing the holding member 240 of the weight member 230 toward the holding member 240 (that is, in the first direction D1) (see FIG. 26). The guide portion 238 guides the movement of the cylindrical member 270 in the radial direction M. The guide portion 238 is located between the first biasing member holding portion 131A and the second biasing member holding portion 131B with respect to the circumferential direction S. As shown in FIG. 25, the guide portion 238 is formed in a rectangular shape in plan view. The guide portion 238 includes a first restricting portion 238S that restricts the cylindrical member 270 from moving in the circumferential direction S, and a second restricting portion 238M that restricts the cylindrical member 270 from moving more than a predetermined distance in the radial direction M. The first restricting portion 238S is provided on each of the first circumferential direction S1 side and the second circumferential direction S2 side with respect to the circumferential direction S. The second restricting portion 238M is provided on each of the outer side M1 and the inner side M2 with respect to the radial direction M. The guide portion 238 has a housing concave groove 238P that is recessed in the direction (that is, the second direction D2) from the holding member 240 toward the weight member 230 with respect to the axial direction (that is, the direction D) of the output shaft 15 and houses a part of the cylindrical member 270. The housing concave groove 238P is defined by the first restricting portion 238S and the second restricting portion 238M.

[0077] As shown in FIG. 22, the cylindrical member 270 is provided between the weight member 230 and the holding member 240 with respect to the axial direction (i.e., direction D) of the output shaft 15. The cylindrical member 270 is arranged to extend in a direction intersecting the radial direction M (here, a direction orthogonal to the radial direction M and the direction D). The cylindrical member 270 rolls with respect to the weight member 230 and the holding member 240. A part of the cylindrical member 270 is accommodated in the holding member side guide portion 245 of the holding member 240, and another part of the cylindrical member 270 is accommodated in the guide portion 238 of the weight member 230. The cylindrical member 270 rolls with respect to the holding member side guide portion 245 and the guide portion 238. As shown in FIG. 25, the cylindrical member 270 is positioned between the first spring 161 and the second spring 162 with respect to the circumferential direction S. The length L9 of the cylindrical member 270 in the circumferential direction S is equal to or greater than one-fourth of the length L8 (see FIG. 14) of the weight side inclined surface 130F in the circumferential direction S.

[0078] As shown in FIG. 27, in a cross-sectional view in a plane including the axial direction (i.e., direction D) and the radial direction M of the output shaft 15, when the weight member 230 is located on the inner side M2 of the radial direction M, at least a part of the cylindrical member 270 overlaps with the spring 160. Here, all of the cylindrical member 270 overlaps with the spring 160. In a cross-sectional view in a plane including the axial direction (i.e., direction D) and the radial direction M of the output shaft 15, when the weight member 230 is located on the inner side M2 of the radial direction M, at least a part of the guide portion 238 overlaps with the spring 160. Here, all of the guide portion 238 overlaps with the spring 160.

[0079] As shown in FIG. 28, in a cross-sectional view in a plane including the axial direction (i.e., direction D) and the radial direction M of the output shaft 15, a straight line CL2 passing through the center 150FC in the radial direction M of the pressing-side inclined surface 150F and parallel to the axial direction (i.e., direction D) of the output shaft 15 passes through the guide portion 238 when the weight member 230 is located on the outer side M1 in the radial direction M. As shown in FIG. 29, when viewed from the axial direction (i.e., direction D) of the output shaft 15 with the weight member 230 located on the inner side M2 in the radial direction M, at least a part of the weight-side inclined surface 130F and the holding member-side guide portion 245 overlap. As shown in FIG. 30, when viewed from the axial direction (i.e., direction D) of the output shaft 15 with the weight member 230 located on the outer side M1 in the radial direction M, the pressing-side inclined surface 150F and at least a part of the guide portion 238 overlap.

[0080] In such a centrifugal clutch mechanism 220, as shown in FIGS. 27 and 29, when no centrifugal force is applied to the weight member 230, the weight member 230 is held at the position PI on the inner side M2 in the radial direction M, and the pressing force between the input-side rotating plate 20 and the output-side rotating plate 22 is released. On the other hand, as shown in FIGS. 28 and 30, when centrifugal force is applied to the weight member 230, the weight member 230 moves from the position PI on the inner side M2 in the radial direction M to the position PO on the outer side M1. When the weight member 230 moves in the radial direction M, it is guided by the guide portion 238 and the holding member-side guide portion 245, and the cylindrical member 270 rolls with respect to the weight member 230 and the holding member 240. At this time, the first plane 133 and the second plane 135 of the weight member 230 do not slide on the sliding surface 145M of the holding member 240.

[0081] <Third Embodiment> As shown in FIG. 31, the holding member 340 according to the third embodiment includes a main body 341, a plurality of engaging claws 143, a plurality of accommodating recesses 345, and a pressing portion 149 (see FIG. 1).

[0082] The main body 341 is formed in a ring shape. As shown in FIG. 31, the main body 341 includes a wall portion 341A. The wall portion 341A is located between the engaging claw 143 and the housing recess 345 with respect to the radial direction M. The wall portion 341A partitions a part of the housing recess 345.

[0083] As shown in FIG. 31, the housing recess 345 is formed in the main body 341 so as to be recessed in the axial direction of the output shaft 15. The housing recess 345 is recessed in the first direction D1. The housing recess 345 movably houses the weight member 130 in the radial direction M. One end of each of the first spring 161 and the second spring 162 abuts against the end portion 345X on the outer side M1 in the radial direction M of the housing recess 345.

[0084] As shown in FIG. 31, the length L10 in the radial direction M of the wall portion 341A is longer than the length L4 in the radial direction M from the outer peripheral edge 141E of the main body 341 to the end portion 143X on the outer side M1 in the radial direction M of the engaging claw 143. Here, the length L10 in the radial direction M of the wall portion 341A is the length in the radial direction M from the outer peripheral edge 141E of the main body 341 to the end portion 345X on the outer side M1 in the radial direction M of the housing recess 345. The length L11 in the circumferential direction S of the wall portion 341A is equal to or greater than the length L2 in the circumferential direction S of the engaging claw 143.

[0085] According to the clutch device 10 of the present embodiment, the main body 341 of the holding member 340 includes a wall portion 341A located between the engaging claw 143 and the housing recess 345 with respect to the radial direction M, and the length L10 in the radial direction M of the wall portion 341A is longer than the length L4 in the radial direction M from the outer peripheral edge 141E of the main body 341 to the end portion 143X on the outer side M1 in the radial direction M of the engaging claw 143. According to the above aspect, since the wall portion 341A is relatively thick, the rigidity of the engaging claw 143 is high. Thereby, for example, even if the weight member 130 comes into contact with the wall portion 341A, the rigidity of the engaging claw 143 is improved, so that breakage of the engaging claw 143 can be suppressed.

[0086] In the clutch device 10 of the present embodiment, the length L11 in the circumferential direction S of the wall portion 341A is equal to or greater than the length L2 in the circumferential direction S of the engaging claw 143. According to the above aspect, the rigidity of the engaging claw 143 can be further increased. <Fourth Embodiment> FIG. 32 is a plan view showing a part of the centrifugal clutch mechanism 420 according to the fourth embodiment. The centrifugal clutch mechanism 420 includes a plurality of weight members 130, a holding member 140, a pressing member 150 (see FIG. 1), a spring 160, and a contact member 170 (see FIG. 1). The plurality of weight members 130 includes a first weight member 130A and a second weight member 130B. The first weight member 130A and the second weight member 130B have the same configuration except that the first weight member 130A is lighter than the second weight member 130B. The first weight member 130A and the second weight member 130B are formed of, for example, different materials. In the example shown in FIG. 1, the first weight member 130A and the second weight member 130B are configured to move the pressing member 150 in the second direction D2.

[0087] As shown in FIG. 32, the first weight member 130A and the second weight member 130B are alternately arranged in the circumferential direction S. That is, one first weight member 130A is located between two second weight members 130B arranged side by side in the circumferential direction S. The number of the first weight members 130A is the same as the number of the second weight members 130B. In the present embodiment, the number of the first weight members 130A is three, and the number of the second weight members 130B is three, but they are not limited to three respectively. When viewed in the axial direction of the output shaft 15, a part of the plurality of first weight members 130A is arranged symmetrically with respect to a straight line LC passing through the center 15C of the output shaft 15, and a part of the plurality of second weight members 130B is arranged symmetrically with respect to the straight line LC.

[0088] As shown in FIGS. 33A and 33B, the first weight member 130A starts to move from the position PI on the inner side M2 in the radial direction M toward the position PO on the outer side M1 in the radial direction M when the engine speed reaches the first engine speed E1. The first engine speed E1 is the engine speed at the start of the vehicle. The first weight member 130A starts to press the pressing member 150 and moves the pressing member 150 in the axial direction (i.e., direction D) when the engine speed reaches the first engine speed E1. The pressing member 150 starts to move from the position PD1 on the most first direction D1 side, which is the initial position, toward the position PD2 on the most second direction D2 side. Until the engine speed reaches the second engine speed E2 from the first engine speed E1, the first weight member 130A continues to move in the radial direction M, and the pressing member 150 continues to move in the second direction D2. The second weight member 130B starts to move from the position PI on the inner side M2 in the radial direction M toward the position PO on the outer side M1 in the radial direction M in the semi-clutch state. The engine speed in the semi-clutch state is higher than the engine speed at the start of the vehicle (here, the first engine speed E1). The second weight member 130B starts to move from the position PI on the inner side M2 in the radial direction M toward the position PO on the outer side M1 in the radial direction M, for example, when the engine speed reaches the second engine speed E2. Until the engine speed reaches the third engine speed E3 from the second engine speed E2, the first weight member 130A does not move in the radial direction M, the pressing member 150 does not move in the direction D, and only the second weight member 130B continues to move in the radial direction M. The second weight member 130B starts to press the pressing member 150 and moves the pressing member 150 in the axial direction (i.e., direction D) when the engine speed reaches the third engine speed E3. When the engine speed reaches the third engine speed E3, the first weight member 130A and the second weight member 130B start to press the pressing member 150 simultaneously, and the pressing member 150 starts to move in the direction D again. Thereafter, the first weight member 130A and the second weight member 130B reach the position PO on the outer side M1 in the radial direction M when the engine speed reaches the sixth engine speed E6. At this time, the pressing member 150 also reaches the position PD2.Thus, since the pressing member 150 is not pressed using all of the first weight member 130A and the second weight member 130B from the beginning, the input-side rotating plate 20 and the output-side rotating plate 22 are not suddenly pressed but are gradually pressed. That is, since the sudden engagement of the clutch can be suppressed, the deterioration of the riding comfort is suppressed. In the present embodiment, the first movement amount MD1 in the radial direction M of the first weight member 130A until the engine speed reaches the second engine speed E2 from the first engine speed E1 is different from the second movement amount MD2 in the radial direction M of the first weight member 130A from the second engine speed E2 to the sixth engine speed E6. Here, the second movement amount MD2 is larger than the first movement amount MD1. Also, the third movement amount MD3 in the radial direction M of the first weight member 130A from the second engine speed E2 to the fifth engine speed E5 is larger than the first movement amount MD1. In FIGS. 33A and 33B, E0 is the engine speed at idling, E4 is the engine speed when a force in the direction from the pressure member 70 toward the clutch center 40 (here, the first direction D1) starts to be generated due to the action of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A, and E5 is the engine speed when the input-side rotating plate 20 and the output-side rotating plate 22 are completely pressed together. The center-side assist cam surface 60A and the pressure-side assist cam surface 90A are configured to start generating a force in the direction from the pressure member 70 toward the clutch center 40 when the engine speed reaches the fourth engine speed E4. Also, in FIG. 33A, the solid line indicates the movement locus of the first weight member 130A, the broken line indicates the movement locus of the second weight member 130B, and the one-dot chain line indicates the movement locus of the first weight member 130A and the second weight member 130B.

[0089] In the examples of FIGS. 33A and 33B, the pressure contact member 150 does not move in the direction D (here, the second direction D2) until the engine speed reaches the third engine speed E3 from the second engine speed E2, but may move continuously in the direction D as the engine speed increases. For example, until the engine speed reaches the third engine speed E3 from the second engine speed E2, the first weight member 130A and the second weight member 130B may move in the radial direction M, and the pressure contact member 150 may move in the direction D. In this case, for example, when the engine speed reaches the second engine speed E2, the first weight member 130A and the second weight member 130B may start pressing the pressure contact member 150 simultaneously. Also, in the example of FIG. 33A, at the third engine speed E3 which is lower than the fourth engine speed E4, the first weight member 130A and the second weight member 130B start pressing the pressure contact member 150 simultaneously, but at an engine speed higher than the fourth engine speed E4, the first weight member 130A and the second weight member 130B may start pressing the pressure contact member 150 simultaneously. That is, at an engine speed lower than the fourth engine speed E4 when a force in the direction from the pressure member 70 toward the clutch center 40 (here, the first direction D1) starts to be generated due to the action of the center side assist cam surface 60A and the pressure side assist cam surface 90A, only the first weight member 130A which is a part of the weight member 130 may press the pressure contact member 150, and the second weight member 130B which is another part of the weight member 130 may not press the pressure contact member 150. In other words, the third engine speed E3 which is the upper limit of the first region RE1 described later may be set to an engine speed higher than the fourth engine speed E4. Thereby, when a force in the direction from the pressure member 70 toward the clutch center 40 starts to be generated due to the action of the center side assist cam surface 60A and the pressure side assist cam surface 90A, since the input side rotating plate 20 and the output side rotating plate 22 are gradually pressed only by the first weight member 130A, sudden engagement of the clutch can be suppressed, and a decrease in riding comfort can be suppressed.

[0090] As shown in FIGS. 33A and 33B, when the engine speed is in the first region RE1, a part of the plurality of weight members 130 (here, the first weight member 130A) presses the contact member 150, and when the engine speed is in the second region RE2, all of the plurality of weight members 130 (here, the first weight member 130A and the second weight member 130B) press the contact member 150. Here, the pressing of the contact member 150 includes a case where the contact member 150 is pressed and the contact member 150 moves in the second direction D2, and a case where the contact member 150 is being pressed but the contact member 150 does not move in the second direction D2. The first region RE1 is from the engine speed at the start of the vehicle (for example, the first engine speed E1) to a predetermined first engine speed (for example, the third engine speed E3) in the semi-clutch state of the engine. The upper limit engine speed of the first region RE1 is lower than the fourth engine speed E4. The second region RE2 is from a predetermined first engine speed (for example, the third engine speed E3) in the semi-clutch state of the engine to a predetermined second engine speed (for example, the sixth engine speed E6) higher than the predetermined first engine speed. Note that the semi-clutch state region RH is from the first engine speed E1 to the fifth engine speed E5.

[0091] Next, the relationship between the engine speed and the pressing contact between the input-side rotating plate 20 and the output-side rotating plate 22 will be described. As shown in FIGS. 33A and 33B, until the engine speed reaches the second rotational speed E2 from the first rotational speed E1, the pressing member 150 presses the flange 68 of the second clutch center 51 in the second direction D2. As a result, the second clutch center 51 moves in the second direction D2 with respect to the first clutch center 41, and the input-side rotating plate 20 and the output-side rotating plate 22 come into contact with each other to enter a semi-clutch state. By entering the semi-clutch state, the rotational driving force of the input shaft begins to be transmitted to the output shaft 15. When the engine speed reaches the second rotational speed E2, when the first weight member 130A attempts to move the pressing member 150 further in the second direction D2, since the input-side rotating plate 20 and the output-side rotating plate 22 are in contact with each other, the pressing member 150 attempts to move the pressure member 70 in the second direction D2 via the input-side rotating plate 20 and the output-side rotating plate 22. Here, the wall surface 84D1 (see FIG. 20) on the first direction D1 side of the spring housing portion 84 of the pressure member 70 is in contact with the wall surface 41D2 (see FIG. 20) on the second direction D2 side of the first clutch center 41, and the pressure member 70 is biased in the first direction D1 by the clutch spring 25. For this reason, until the force in the second direction D2 acting on the pressing member 150 from the weight member 130 (here, the first weight member 130A and the second weight member 130B) exceeds the spring force of the clutch spring 25 as the engine speed further increases from the second rotational speed E2, the pressing member 150 stays at the position PDS (see FIG. 33B) at the second rotational speed E2. That is, the pressure member 70 is held in a state of being in contact with the wall surface 41D2 on the second direction D2 side of the first clutch center 41 by the spring force of the clutch spring 25. Then, when the engine speed reaches the third rotational speed E3 and the second weight member 130B starts to press the pressing member 150, since both the first weight member 130A and the second weight member 130B press the pressing member 150, the force in the second direction D2 acting on the pressing member 150 from the weight member 130 exceeds the spring force of the clutch spring 25.As a result, the pressing member 150 further moves in the second direction D2, moving the second clutch center 51 and the pressure member 70 in the second direction D2. Along with this, the input-side rotating plate 20 and the output-side rotating plate 22 are further pressed against each other, and when the engine speed is the fifth rotational speed E5, the input-side rotating plate 20 and the output-side rotating plate 22 are completely pressed against each other.

[0092] <Fifth Embodiment> FIG. 34 is a plan view showing a part of the centrifugal clutch mechanism 520 according to the fifth embodiment. The centrifugal clutch mechanism 520 includes a plurality of weight members 130, a holding member 140, a pressing member 150 (see FIG. 1), a spring 160, and a contact member 170 (see FIG. 1). The plurality of weight members 130 includes a first weight member 130A and a second weight member 130B. The first weight member 130A and the second weight member 130B have the same configuration except that the number of springs 160 biasing them toward the inner side M2 in the radial direction M is different. The first weight member 130A is biased toward the inner side M2 in the radial direction M by one spring 160. The second weight member 130B is biased toward the inner side M2 in the radial direction M by two springs 160. Note that the timing of the start of movement, the arrangement, etc. of the first weight member 130A and the second weight member 130B according to the fifth embodiment are the same as those of the first weight member 130A and the second weight member 130B according to the fourth embodiment.

[0093] <Sixth Embodiment> FIG. 35 is a plan view showing a part of the centrifugal clutch mechanism 620 according to the sixth embodiment. The centrifugal clutch mechanism 620 includes a plurality of weight members 130, a holding member 140, a pressing member 150 (see FIG. 1), a spring 160, a contact member 170 (see FIG. 1), and a restraining member 190. The plurality of weight members 130 includes a first weight member 130A and a second weight member 130B. The first weight member 130A and the second weight member 130B have the same configuration except that a second restraining member 190B, which will be described later, is provided on the second weight member 130B. Note that the timing and arrangement of the start of movement of the first weight member 130A and the second weight member 130B according to the sixth embodiment are the same as those of the first weight member 130A and the second weight member 130B according to the fourth embodiment.

[0094] As shown in FIG. 35, the suppression member 190 includes a first suppression member 190A provided on the holding member 140 and a second suppression member 190B provided on the second weight member 130B. The first suppression member 190A and the second suppression member 190B are, for example, magnets. When the second weight member 130B is at the position P1 on the inner side M2 in the radial direction M, the first suppression member 190A and the second suppression member 190B are attracted to each other by magnetic force. The suppression member 190 suppresses the start of the movement of the second weight member 130B from the position P1 on the inner side M2 in the radial direction M to the position P0 on the outer side M1 in the radial direction M until the centrifugal force reaches a predetermined magnitude (for example, until the second rotational speed E2 is reached). That is, when the attracting force between the first suppression member 190A and the second suppression member 190B is greater than the centrifugal force, the second weight member 130B does not move in the radial direction M. The suppression member 190 suppresses the second weight member 130B from pressing the pressing member 150 until the centrifugal force reaches a predetermined magnitude. When the centrifugal force becomes greater than a predetermined magnitude (for example, when the second rotational speed E2 is reached), the suppression member 190 allows the start of the movement of the second weight member 130B from the position P1 on the inner side M2 in the radial direction M to the position P0 on the outer side M1 in the radial direction M. That is, when the centrifugal force becomes greater than the attracting force between the first suppression member 190A and the second suppression member 190B, the second weight member 130B moves in the radial direction M. The suppression member 190 allows the second weight member 130B to press the pressing member 150 when the centrifugal force becomes greater than a predetermined magnitude.

[0095] <Seventh Embodiment> FIG. 36 is a plan view showing a part of the centrifugal clutch mechanism 720 according to the seventh embodiment. The centrifugal clutch mechanism 720 has the same configuration as the centrifugal clutch mechanism 420, except that the number of the first weight members 130A is different from the number of the second weight members 130B. The number of the first weight members 130A is larger than the number of the second weight members 130B. Note that the number of the second weight members 130B may be larger than the number of the first weight members 130A. Also, in the centrifugal clutch mechanisms 520 and 620 described above, similarly to the centrifugal clutch mechanism 720, the number of the first weight members 130A and the number of the second weight members 130B may be different. Note that the timing of the start of movement, the arrangement, etc. of the first weight members 130A and the second weight members 130B according to the seventh embodiment are the same as those of the first weight members 130A and the second weight members 130B according to the fourth embodiment.

[0096] <Eighth Embodiment> FIG. 37 is a cross-sectional view showing the centrifugal clutch mechanism 820 according to the eighth embodiment and its periphery. The centrifugal clutch mechanism 820 includes a plurality of weight members 830, a holding member 840, a pressing member 850, a spring 160, and a contact member 170. As shown in FIG. 38, the plurality of weight members 830 include a first weight member 830A and a second weight member 830B.

[0097] As shown in FIGS. 37 and 38, the holding member 840 holds the weight members 830 so as to be movable between a position PI on the inner side M2 in the radial direction M and a position PO on the outer side M1 in the radial direction M. The holding member 840 is formed in an annular shape. The holding member 840 is formed by die casting of aluminum. The holding member 840 includes a main body 141, a plurality of engaging claws 143, a plurality of housing recesses 145, and a pressing portion 149 (see FIG. 1).

[0098] As shown in FIG. 39, the weight member 830 includes a weight body 830X, a through hole 833, a cylindrical member 834, and a spherical member 835. The through hole 833 is formed in the weight body 830X. The through hole 833 is a hole that penetrates the weight body 830X in the axial direction (i.e., direction D) of the output shaft 15. A cylindrical member 834 that rotatably holds the spherical member 835 is provided in the through hole 833. The cylindrical member 834 is fitted inside the through hole 833 and extends in the axial direction (i.e., direction D) of the output shaft 15. A part of the spherical member 835 protrudes from the opening of the through hole 833. The spherical member 835 is, for example, a steel ball. The spherical member 835 includes a first spherical member 835A that can come into contact with (abut against) the pressing member 850 and a second spherical member 835B that can come into contact with (abut against) the holding member 840. The first spherical member 835A is provided so as to be rotatable with respect to an inclined surface 856 of the pressing member 850, which will be described later. The second spherical member 835B is provided so as to be rotatable with respect to the accommodation recess 145 of the holding member 840. The first spherical member 835A is an example of a contact portion on the weight member side.

[0099] The pressing member 850 is configured to move in the axial direction (here, the second direction D2) of the output shaft 15 when the weight member 830 moves from the position PI on the inner side M2 in the radial direction M to the position PO on the outer side M1 in the radial direction M, so that the input-side rotating plate 20 and the output-side rotating plate 22 can be pressed against each other. As shown in FIG. 40, the pressing member 850 is formed in an annular shape. The pressing member 850 includes an annular main body portion 851, a plurality of convex portions 855, and a plurality of engaging claws 843. The engaging claws 843 protrude from the outer peripheral edge 851E of the main body portion 851 toward the outer side M1 in the radial direction M. The engaging claws 843 are formed integrally with the main body portion 851. The engaging claws 843 engage with the clutch housing 30 (see FIG. 1). The plurality of engaging claws 843 are arranged in the circumferential direction S.

[0100] As shown in FIG. 40, the convex portion 855 protrudes from the main body portion 851 in the axial direction of the output shaft 15 (here, the first direction D1). The convex portion 855 extends in the radial direction M. A plurality of convex portions 855 are arranged in the circumferential direction S. The convex portion 855 has an inclined surface 856 that contacts the weight member 830. More specifically, the inclined surface 856 contacts (abuts) the first spherical member 835A of the weight member 830. The inclined surface 856 is inclined with respect to the axial direction of the output shaft 15 (i.e., direction D). The inclined surface 856 is inclined toward the first direction D1 as it goes toward the outside M1 in the radial direction M. A guide groove 857 for guiding the movement of the first spherical member 835A in the radial direction M is formed in the inclined surface 856. The guide groove 857 extends in the radial direction M. The inclined surface 856 is an example of a pressure contact member side contact portion. When the weight member 830 moves from the position PI inside the radial direction M to the position PO outside the radial direction M, the first spherical member 835A and the inclined surface 856 come into contact, and the pressure contact member 850 moves in the axial direction of the output shaft 15 (here, the second direction D2).

[0101] In the eighth embodiment, the first weight member 830A and the second weight member 830B are such that the first weight member 830A is lighter than the second weight member 830B. Note that the timing of the start of movement, the arrangement, etc. of the first weight member 830A and the second weight member 830B according to the eighth embodiment are the same as those of the first weight member 130A and the second weight member 130B according to the fourth embodiment. Also, similar to the fifth embodiment, in the first weight member 830A and the second weight member 830B, the number of springs 160 that bias toward the inside M2 in the radial direction M may be different. Also, similar to the sixth embodiment, the centrifugal clutch mechanism 820 may include a suppression member 190. Also, similar to the seventh embodiment, the number of the first weight members 830A and the number of the second weight members 830B may be different.

[0102] In the above-described eighth embodiment, the first weight member 830A was lighter than the second weight member 830B, but the present invention is not limited thereto. For example, when the first weight member 830A and the second weight member 830B have the same configuration, as shown in FIG. 41, the position PIA on the inner side M2 in the radial direction M of the first weight member 830A and the position PIB on the inner side M2 in the radial direction M of the second weight member 830B may be different with respect to the radial direction M. In this case, between the position PIA and the position PIB, the first spherical member 835A of the first weight member 830A presses the pressure contact member 850 in the second direction D2 via the inclined surface 856. At this time, the first spherical member 835A of the second weight member 830B does not press the pressure contact member 850 in the second direction D2. And between the position PIB and the position PO, the first spherical member 835A of the first weight member 830A presses the pressure contact member 850 in the second direction D2 via the inclined surface 856, and the first spherical member 835A of the second weight member 830B presses the pressure contact member 850 in the second direction D2 via the inclined surface 856. That is, the first weight member 830A presses the pressure contact member 850 within the range of the region PRA, and the second weight member 830B presses the pressure contact member 850 within the range of the region PRB. In addition, in this modified example, the shape of the first spherical member 835A of the first weight member 830A and the shape of the first spherical member 835A of the second weight member 830B may be different. In FIG. 41, the first spherical member 835A at the position PI on the inner side M2 in the radial direction M is shown by a solid line, and the first spherical member 835A at the position PO on the outer side M1 in the radial direction M is shown by a one-dot chain line.

[0103] In the above-described eighth embodiment, the first weight member 830A is lighter than the second weight member 830B, and the inclined surface 856 on which the first spherical member 835A of the first weight member 830A rolls and the inclined surface 856 on which the first spherical member 835A of the second weight member 830B rolls have the same shape, but it is not limited thereto. For example, when the first weight member 830A and the second weight member 830B have the same configuration, as shown in FIG. 42, in a cross-sectional view including the axis of the output shaft 15, the inclined surface 856A on which the first spherical member 835A of the first weight member 830A rolls and the inclined surface 856B on which the first spherical member 835A of the second weight member 830B rolls may have different shapes. That is, the length in the radial direction M of the inclined surface 856A may be longer than the length in the radial direction M of the inclined surface 856B. The end 856BM2 of the inner side M2 in the radial direction M of the inclined surface 856B is located on the outer side M1 in the radial direction M with respect to the end 856AM2 of the inner side M2 in the radial direction M of the inclined surface 856A. In this case, the position PIA of the inner side M2 in the radial direction M of the first weight member 830A and the position PIB of the inner side M2 in the radial direction M of the second weight member 830B are different with respect to the radial direction M. And between the position PIA and the position PIB, the first spherical member 835A of the first weight member 830A presses the pressure contact member 850 in the second direction D2 via the inclined surface 856A. At this time, the first spherical member 835A of the second weight member 830B does not press the pressure contact member 850 in the second direction D2. And between the position PIB and the position PO, the first spherical member 835A of the first weight member 830A presses the pressure contact member 850 in the second direction D2 via the inclined surface 856A, and the first spherical member 835A of the second weight member 830B presses the pressure contact member 850 in the second direction D2 via the inclined surface 856B. That is, the first weight member 830A presses the pressure contact member 850 within the range of the region PRA, and the second weight member 830B presses the pressure contact member 850 within the range of the region PRB. In addition, in this modification, the position of the inner side M2 in the radial direction M of the second weight member 830B may be the same as the position PIA of the inner side M2 in the radial direction M of the first weight member 830A, and the second weight member 830B may be configured to contact (i.e., press the inclined surface 856B) from the end 856BM2 of the inner side M2 in the radial direction M of the inclined surface 856B.Also, the positions of the inclined surface 856A and the inclined surface 856B in the radial direction M may be different. In FIG. 42, the first spherical member 835A at the position PI inside the radial direction M (M2) is shown by a solid line, and the first spherical member 835A at the position PO outside the radial direction M (M1) is shown by a one-dot chain line.

[0104] As described above, the preferred embodiments of the present invention have been described. However, the above-described embodiments are merely examples, and the present invention can be implemented in various other forms.

[0105] In each of the above-described embodiments, the spring 160 has been cited as an example of the biasing member, but it is not limited thereto. The biasing member may be an elastic body such as rubber, for example.

[0106] In each of the above-described embodiments, the pressure-contact side inclined surface 150F has been cited as an example of the pressure-contact side sliding portion, and the weight side inclined surface 130F has been cited as an example of the weight side sliding portion. Both were inclined surfaces inclined with respect to the axial direction (i.e., direction D) of the output shaft 15, but it is not limited thereto. At least one of the pressure-contact side sliding portion and the weight side sliding portion may be an inclined surface inclined with respect to the axial direction of the output shaft 15, and the other may be a protrusion or the like instead of an inclined surface.

[0107] In each of the above-described embodiments, the weight members 130 and 230 have included the biasing member holding portion 131, but they may not include the biasing member holding portion 131. In this case, for example, the spring 160 is arranged so as to abut against the end portion (for example, the end surface) on the outer side M1 in the radial direction M of the weight members 130 and 230.

[0108] In the first embodiment described above, the weight member 130 has included the first flat surface 133 and the second flat surface 135 provided slidably with respect to the holding member 140, but it may include only one of them. The first flat surface 133 and the second flat surface 135 are examples of flat surfaces. In this case, the weight member 130 itself can slide better with the holding member 140 via the first flat surface 133 or the second flat surface 135.

[0109] In each of the above-described embodiments, the pressing member 150 was configured to indirectly press the input-side rotating plate 20 and the output-side rotating plate 22 via the flange 68 of the second clutch center 51, but the present invention is not limited thereto. The pressing member 150 may be configured to directly press the input-side rotating plate 20 or the output-side rotating plate 22, thereby pressing the input-side rotating plate 20 and the output-side rotating plate 22 against each other.

[0110] In each of the above-described embodiments, the pressure member 70 holds one output-side rotating plate 22, but it may hold a plurality of output-side rotating plates 22.

[0111] In each of the above-described embodiments, the pressure member 70 holds a part of a plurality of output-side rotating plates 22, and the clutch center 40 (more specifically, the second clutch center 51) holds the other part of the plurality of output-side rotating plates 22, but the present invention is not limited thereto. For example, the pressure member 70 may hold all of the plurality of output-side rotating plates 22.

[0112] In each of the above-described embodiments, the clutch center 40 includes the first clutch center 41 and the second clutch center 51, but the first clutch center 41 and the second clutch center 51 may be integrally formed.

[0113] In each of the above-described embodiments, the weight member 130 was configured to directly press the pressing member 150, but it may be configured to indirectly press the pressing member 150.

[0114] In each of the above-described embodiments, an engine was used as the drive source, but the drive source is not limited to an engine and may be, for example, an electric motor or the like.

[0115] The shapes of the weight members 130, 230, and 830 are not limited to the shapes of the above-described embodiments and may be, for example, spherical.

[0116] The technology disclosed herein can be applied to various types of clutch devices. In each of the above-described embodiments, a so-called internal cut type clutch device is described as an example, in which, in the axial direction of the output shaft 15, the pressure member 70 is located on the side opposite to the clutch housing 30 with the clutch center 40 interposed therebetween. However, the present invention is not limited thereto. For example, in a so-called external cut type clutch device in which, in the axial direction of the output shaft 15, the pressure member 70 is located between the clutch center 40 and the clutch housing 30, the present invention can be similarly applied.

Description of Reference Numerals

[0117] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 30 Clutch housing 40 Clutch center 70 Pressure member 120 Centrifugal clutch mechanism 130 Weight member 140 Holding member 141 Body 141A Wall portion 141B Protrusion 141E Outer peripheral edge 141T Thick portion 143 Engaging claw 143A Head portion 143B Root portion 145 Accommodating recess 150 Pressing member 160 Spring (biasing member) 161 First spring 162 Second spring

Claims

1. A clutch device that transmits or blocks the rotational driving force of an input shaft to an output shaft, accommodated in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and a clutch center that is rotationally driven together with the output shaft, a plurality of output-side rotating plates that are provided so as to be able to approach or separate from the clutch center and are alternately arranged with the input-side rotating plates, and at least a part of the plurality of output-side rotating plates is held, and a pressure member that can press the input-side rotating plates and the output-side rotating plates, having a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position by centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, bringing the input-side rotating plates into pressure contact with the output-side rotating plates to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are in the inner position in the radial direction, releasing the pressure contact force between the input-side rotating plates and the output-side rotating plates to block the transmission of the rotational driving force of the input shaft to the output shaft, and a centrifugal clutch mechanism, wherein the centrifugal clutch mechanism has a holding member that movably holds the weight members between the inner position in the radial direction and the outer position in the radial direction, a biasing member provided on the holding member that biases the weight members inward in the radial direction, and a pressure contact member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction, and presses the input-side rotating plates and the output-side rotating plates, wherein the weight members include a first weight member that starts to move from the inner position in the radial direction toward the outer position in the radial direction when the rotational speed of the drive source is a first rotational speed, and a second weight member that starts to move from the inner position in the radial direction toward the outer position in the radial direction when the rotational speed of the drive source is a second rotational speed higher than the first rotational speed, a clutch device.

2. The clutch device according to claim 1, wherein the second weight member starts to move from the inner position in the radial direction toward the outer position in the radial direction in a semi-clutch state.

3. The clutch device according to claim 1, wherein one of the first weight members is located between two of the second weight members arranged in the circumferential direction.

4. The weight member includes a plurality of the first weight members and a plurality of the second weight members. The clutch device according to claim 1, wherein when viewed in the axial direction of the output shaft, a part of the plurality of the first weight members is arranged symmetrically with respect to a straight line passing through the center of the output shaft, and a part of the plurality of the second weight members is arranged symmetrically with respect to the straight line.

5. The weight member includes a plurality of the first weight members and a plurality of the second weight members. The clutch device according to claim 1, wherein the number of the first weight members is different from the number of the second weight members.

6. The clutch device according to claim 5, wherein the number of the second weight members is larger than the number of the first weight members.

7. The weight member includes a plurality of the first weight members and a plurality of the second weight members. The clutch device according to claim 1, wherein the number of the first weight members is the same as the number of the second weight members.

8. The first weight member is configured to reach a position on the outer side in the radial direction when the rotational speed of the drive source is a third rotational speed higher than the second rotational speed. The clutch device according to claim 1, wherein a first radial movement amount of the first weight member from the first rotational speed to the second rotational speed is different from a second radial movement amount of the first weight member from the second rotational speed to the third rotational speed.

9. The clutch device according to claim 8, wherein the second movement amount is larger than the first movement amount.

10. The clutch device according to claim 1, wherein an inner position in the radial direction of the first weight member and an inner position in the radial direction of the second weight member are different in the radial direction.

11. A clutch device for transmitting or blocking a rotational driving force of an input shaft to an output shaft, comprising: a clutch housing that houses a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft, and a clutch center that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or separate from the clutch center, holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates, and can press the input-side rotating plates and the output-side rotating plates. It includes a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position by centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, the input-side rotating plate and the output-side rotating plate are pressed against each other so that the rotational driving force of the input shaft can be transmitted to the output shaft, and when the weight members are in the inner position in the radial direction, the pressing force between the input-side rotating plate and the output-side rotating plate is released so that the transmission of the rotational driving force of the input shaft to the output shaft can be blocked, and a centrifugal clutch mechanism. The centrifugal clutch mechanism is a holding member that movably holds the weight members between the inner position in the radial direction and the outer position in the radial direction, a biasing member provided on the holding member to bias the weight members inward in the radial direction, a pressing member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction, and presses the input-side rotating plate and the output-side rotating plate against each other. The weight members include a first weight member and a second weight member. The centrifugal clutch mechanism includes a suppressing member that suppresses the start of the movement of the second weight member from the inner position in the radial direction to the outer position in the radial direction until the centrifugal force reaches a predetermined magnitude. The clutch device.

12. The clutch device according to claim 11, wherein the suppressing member allows the start of the movement of the second weight member from the inner position in the radial direction to the outer position in the radial direction when the centrifugal force becomes greater than the predetermined magnitude.

13. The clutch device according to claim 11, wherein one of the first weight members is located between two of the second weight members arranged in the circumferential direction.

14. The weight members include a plurality of the first weight members and a plurality of the second weight members. The clutch device according to claim 11, wherein when viewed in the axial direction of the output shaft, a part of the plurality of first weight members is arranged symmetrically with respect to a straight line passing through the center of the output shaft, and a part of the plurality of second weight members is arranged symmetrically with respect to the straight line.

15. The weight members include a plurality of the first weight members and a plurality of the second weight members. The clutch device according to claim 11, wherein the number of the first weight members is different from the number of the second weight members.

16. The clutch device according to claim 15, wherein the number of the first weight members is larger than the number of the second weight members.

17. The weight members include a plurality of the first weight members and a plurality of the second weight members, The clutch device according to claim 11, wherein the number of the first weight members is the same as the number of the second weight members.

18. A clutch device that transmits or blocks the rotational driving force of an input shaft to an output shaft, A clutch center that is housed in a clutch housing that holds a plurality of input-side rotating plates that are rotationally driven by the rotational driving of the input shaft and that rotates together with the output shaft, A pressure member that is provided so as to be able to approach or separate from the clutch center, holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plates, and can press the input-side rotating plates and the output-side rotating plates, It has a plurality of weight members configured to be movable from a position on the inner side in the radial direction to a position on the outer side by the centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the position on the outer side in the radial direction, the input-side rotating plate and the output-side rotating plate are brought into pressure contact to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are in the position on the inner side in the radial direction, the pressure contact force between the input-side rotating plate and the output-side rotating plate is released to block the transmission of the rotational driving force of the input shaft to the output shaft, and a centrifugal clutch mechanism, The centrifugal clutch mechanism is A holding member that movably holds the weight members between the position on the inner side in the radial direction and the position on the outer side in the radial direction, A biasing member that is provided on the holding member and biases the weight members inward in the radial direction, A pressure contact member that moves in the axial direction of the output shaft when the weight members move from the position on the inner side in the radial direction to the position on the outer side in the radial direction and brings the input-side rotating plate and the output-side rotating plate into pressure contact, The weight members are A first weight member that starts pressing the pressure contact member and moves the pressure contact member in the axial direction when the rotational speed of the drive source is a first rotational speed, A clutch device, comprising: a second weight member configured to start pressing the pressing member and move the pressing member in the axial direction when the rotational speed of the drive source is a second rotational speed higher than the first rotational speed.

19. The weight member includes a weight member side contact portion that can contact the pressing member. The pressing member includes a pressing member side contact portion that can contact the weight member side contact portion. The weight member is configured such that when the weight member moves from an inner position in the radial direction to an outer position in the radial direction, the weight member side contact portion contacts the pressing member side contact portion, and the pressing member moves in the axial direction of the output shaft. The clutch device according to claim 18, wherein in a cross-sectional view including the axis of the output shaft, at least one of the shape and position of the weight member side contact portion of the first weight member is different from at least one of the shape and position of the weight member side contact portion of the second weight member.

20. The weight member includes a weight member side contact portion that can contact the pressing member. The pressing member includes a pressing member side contact portion that can contact the weight member side contact portion. The weight member is configured such that when the weight member moves from an inner position in the radial direction to an outer position in the radial direction, the weight member side contact portion contacts the pressing member side contact portion, and the pressing member moves in the axial direction of the output shaft. The clutch device according to claim 18, wherein in a cross-sectional view including the axis of the output shaft, at least one of the shape and position of the pressing member side contact portion that contacts the weight member side contact portion of the first weight member is different from at least one of the shape and position of the pressing member side contact portion that contacts the weight member side contact portion of the second weight member.

21. The clutch device according to claim 19 or 20, wherein an end portion on the inner diameter side in the radial direction of the pressing member side contact portion that contacts the weight member side contact portion of the second weight member is located on the outer side in the radial direction compared to an end portion on the inner diameter side in the radial direction of the pressing member side contact portion that contacts the weight member side contact portion of the first weight member.

22. A clutch device configured to transmit or cut off a rotational driving force of an input shaft to an output shaft, comprising: a clutch center that is housed in a clutch housing that holds a plurality of input side rotating plates that are rotationally driven by the rotational driving of the input shaft and that rotates together with the output shaft. and a clutch center that rotates together with the output shaft and is housed in a clutch housing that holds a plurality of input side rotating plates that are rotationally driven by the rotational driving of the input shaft. A pressure member that is provided so as to be able to approach or separate from the clutch center, holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plate, and can press the input-side rotating plate and the output-side rotating plate. A centrifugal clutch mechanism having a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position by centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, the input-side rotating plate and the output-side rotating plate are brought into pressure contact to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are in the inner position in the radial direction, the pressure contact force between the input-side rotating plate and the output-side rotating plate is released to block the transmission of the rotational driving force of the input shaft to the output shaft. The centrifugal clutch mechanism includes: A holding member that movably holds the weight members between the inner position in the radial direction and the outer position in the radial direction. A biasing member provided on the holding member to bias the weight members inward in the radial direction. A pressure contact member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction, and presses the input-side rotating plate and the output-side rotating plate. The weight members include a first weight member and a second weight member. The centrifugal clutch mechanism includes a suppressing member that suppresses the second weight member from pressing the pressure contact member until the centrifugal force reaches a predetermined magnitude. A clutch device.

23. A clutch device that transmits or blocks the rotational driving force of an input shaft to an output shaft, It is 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 a clutch center that is rotationally driven together with the output shaft. A pressure member that is provided so as to be able to approach or separate from the clutch center, holds at least a part of a plurality of output-side rotating plates that are alternately arranged with the input-side rotating plate, and can press the input-side rotating plate and the output-side rotating plate. It includes a centrifugal clutch mechanism having a plurality of weight members configured to be movable from an inner position in the radial direction to an outer position due to centrifugal force accompanying the rotation of the clutch housing, and when the weight members are in the outer position in the radial direction, the input-side rotating plate and the output-side rotating plate are pressed against each other so that the rotational driving force of the input shaft can be transmitted to the output shaft, and when the weight members are in the inner position in the radial direction, the pressing force between the input-side rotating plate and the output-side rotating plate can be released to block the transmission of the rotational driving force of the input shaft to the output shaft. The centrifugal clutch mechanism is a holding member that movably holds the weight members between the inner position in the radial direction and the outer position in the radial direction, a biasing member provided on the holding member for biasing the weight members inward in the radial direction, and a pressing member that moves in the axial direction of the output shaft when the weight members move from the inner position in the radial direction to the outer position in the radial direction, and presses the input-side rotating plate and the output-side rotating plate against each other. A clutch device configured such that when the rotational speed of the drive source is in a first region, a part of the plurality of weight members presses the pressing member, and when the rotational speed of the drive source is in a second region, all of the plurality of weight members press the pressing member.

24. The first region is a predetermined first rotational speed of the drive source in a semi-clutch state from the rotational speed of the drive source at the start of vehicle travel, The second region is a predetermined second rotational speed higher than the predetermined first rotational speed from the predetermined first rotational speed. The clutch device according to claim 23.

25. The clutch center includes a center-side cam portion having a center-side assist cam surface that generates a force in a direction from the pressure member toward the clutch center to increase the pressing force between the input-side rotating plate and the output-side rotating plate when rotating relative to the pressure member. The pressure member is provided so as to be contactable with the center-side assist cam surface, and includes a pressure-side cam portion having a pressure-side assist cam surface that generates the force when rotating relative to the clutch center. The upper limit rotational speed of the first region is lower than the rotational speed at which the force begins to be generated by the action of the center-side assist cam surface and the pressure-side assist cam surface. The clutch device according to claim 23.

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