Clutch device

Abstract

A clutch device 10 comprises a centrifugal clutch mechanism 120 including a weight member 130. The centrifugal clutch mechanism 120 comprises: a holding member 140 that holds the weight member 130; a spring 160 that energizes the weight member 130 to the inner side M2 in the radial direction M; and a pressure contact member 150 that has a pressure contact-side inclined surface 150F provided so as to be capable of coming into contact with the weight member 130 and that brings an input-side rotary plate 20 and an output-side rotary plate 22 into pressure contact with each other. The weight member 130 has a first flat surface that is slidable relative to the holding member 140, and a weight-side inclined surface 130F that is slidable relative to the pressure contact-side inclined surface 150F.

Description

Clutch device

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

[0002] Straddle-type vehicles such as motorcycles are equipped with a clutch device that can transmit and interrupt the rotational driving force of a driving source such as an engine to a driving wheel. For example, Patent Document 1 discloses a clutch device that has an input member (hereinafter referred to as an input shaft) connected to the engine, an output member (hereinafter referred to as an output shaft) connected to the driving wheel, a clutch member (hereinafter referred to as a clutch center) connected to the output shaft, and a pressure member that can move toward or away from the clutch center.

[0003] The clutch device in Patent Document 1 also includes a centrifugal clutch mechanism that includes a weight member that moves radially and a retaining member that houses the weight member. The weight member moves from a radially inner position to a radially outer position due to centrifugal force generated by rotation of the clutch housing, and transmits the driving force of the engine to the wheels by pressing a driving clutch plate (hereinafter referred to as an input rotating plate) and a driven clutch plate (hereinafter referred to as an output rotating plate) together.

[0004] Japanese Patent Application Laid-Open No. 2022-30211

[0005] In the centrifugal clutch mechanism described in Patent Document 1, when a weight member housed in a retaining member moves radially, a second spherical member attached to the weight member rolls relative to the retaining member. The second spherical member is held in a state where a portion of the second spherical member protrudes from an opening of a through-hole formed in a separate weight member. Because the weight member and the second spherical member move together, large vibrations are generated in the centrifugal clutch mechanism when starting, which may result in a deterioration in ride comfort. In addition, the use of multiple spherical members increases the number of parts, resulting in increased assembly time and costs.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide a clutch device that suppresses deterioration in ride comfort when starting.

[0007] A clutch device according to the present invention is a clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, and includes: 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 drive of the input shaft and that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or move away from the clutch center and that holds at least some of the plurality of output side rotating plates that are arranged alternately with the input side rotating plates and that is capable of pressing the input side rotating plates and the output side rotating plates; and a plurality of weight members that are configured to be movable from a radially inner position to an outer position by centrifugal force that accompanies rotation of the clutch housing, and when the weight members are at the radially outer position, they press the input side rotating plates and the output side rotating plates together, making it possible to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are at the radially inner position, they release the pressing force between the input side rotating plates and the output side rotating plates to allow the rotation of the input shaft and a centrifugal clutch mechanism capable of blocking the transmission of a rolling driving force to the output shaft, the centrifugal clutch mechanism including a holding member that holds the weight member movably between an inner position in the radial direction and an outer position in the radial direction, a biasing member that is provided on the holding member and biases the weight member inward in the radial direction, and a pressure-contact side sliding portion that is provided so as to be able to come into contact with the weight member, and the weight member moves from the inner position in the radial direction to the outer position in the radial direction to block the transmission of a rolling driving force to the output shaft. and a pressing member that moves in the axial direction of the shaft to press the input side rotating plate and the output side rotating plate together, and the weight member has a first plane that is a plane extending in a direction intersecting the axial direction of the output shaft and is slidable against the holding member, and a weight side sliding portion that is a plane extending in a direction intersecting the axial direction of the output shaft and is slidable against the pressing side sliding portion, and at least one of the pressing side sliding portion and the weight side sliding portion is an inclined surface that is inclined with respect to the axial direction of the output shaft.

[0008] In the clutch device according to the present invention, the weight member has a first flat surface that extends in a direction intersecting the axial direction of the output shaft and is slidable relative to the retaining member. Because the weight member itself slides against the retaining member via the first flat surface, vibrations occurring in the centrifugal clutch mechanism during starting can be suppressed. This means that a decrease in ride comfort during starting can be suppressed. Furthermore, in addition to the first flat surface that is slidable relative to the retaining member, the weight member also has a weight-side sliding portion that is slidable relative to the pressure-contact-side sliding portion of the pressure-contact member. Because the weight member itself is slidable relative to the retaining member and the pressure-contact member, the clutch device can be manufactured easily with a small number of parts and at low cost.

[0009] Another clutch device according to the present invention is a clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, and includes a clutch center that is accommodated 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 that rotates together with the output shaft, a pressure member that is provided so as to be able to approach or move away from the clutch center and that holds at least some of a plurality of output side rotating plates that are arranged alternately with the input side rotating plates and that can press the input side rotating plates and the output side rotating plates, and a plurality of weight members that are configured to be movable from an inner position to an outer position in the radial direction by centrifugal force that accompanies rotation of the clutch housing, and that the weight members are arranged on the outer side in the radial direction. and a centrifugal clutch mechanism that presses the input side rotating plate and the output side rotating plate together when the weight member is at the radially inner position, thereby enabling transmission of the rotational drive force of the input shaft to the output shaft, and that releases the pressing force between the input side rotating plate and the output side rotating plate when the weight member is at the radially inner position, thereby blocking transmission of the rotational drive force of the input shaft to the output shaft, wherein the centrifugal clutch mechanism includes: a holding member that holds the weight member movably between the radially inner position and the radially outer position; a pressing member that moves in the axial direction of the output shaft as the weight member moves from the radially inner position to the radially outer position, thereby pressing the input side rotating plate and the output side rotating plate together; a cylindrical member that is provided between the weight member and the retaining member in the axial direction of the output shaft, that extends in a direction intersecting the radial direction, and that rolls relative to the weight member and the retaining member, wherein the weight member has a guide portion that is formed on a surface facing the retaining member, that holds the cylindrical member so that a part of the cylindrical member protrudes from the surface of the weight member facing the retaining member toward the retaining member, and that guides the radial movement of the cylindrical member.

[0010] In another clutch device according to the present invention, the weight member includes a guide portion formed on a surface facing the retaining member, the guide portion holding the cylindrical member so that a portion of the cylindrical member protrudes from the surface of the weight member facing the retaining member toward the retaining member, and the guide portion guides the radial movement of the cylindrical member. Here, the cylindrical member is rollable relative to the weight member and the retaining member, and is guided by the guide portion so that only the cylindrical member can move radially. This suppresses vibrations in the centrifugal clutch mechanism when starting, thereby suppressing a deterioration in ride comfort when starting.

[0011] Another clutch device according to the present invention is a clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, and includes: 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 drive of the input shaft and that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or move away from the clutch center and that holds at least some of the plurality of output side rotating plates that are arranged alternately with the input side rotating plates and that is capable of pressing the input side rotating plates and the output side rotating plates; and a plurality of weight members that are configured to be movable from a radially inner position to an outer position by centrifugal force that accompanies rotation of the clutch housing, and when the weight members are at the radially outer position, they press the input side rotating plates and the output side rotating plates together, making it possible to transmit the rotational driving force of the input shaft to the output shaft, and when the weight members are at the radially inner position, they release the pressing force between the input side rotating plates and the output side rotating plates to press the input shaft. and a centrifugal clutch mechanism capable of blocking transmission of rotational driving force to the output shaft, wherein the centrifugal clutch mechanism includes a holding member that holds the weight member movably between the radially inner position and the radially outer position, a biasing member that is provided on the holding member and biases the weight member inward in the radial direction, and a pressure-contact side sliding portion that is provided so as to be able to come into contact with the weight member, and wherein the rotational driving force is blocked from being transmitted to the output shaft by the weight member moving from the radially inner position to the radially outer position. and a pressing member that moves in the axial direction of the shaft and presses the input side rotating plate and the output side rotating plate together, and the weight member has a plane that extends in a direction intersecting the axial direction of the output shaft and is slidable against the holding member, and a weight side sliding portion that is located on the opposite side of the plane in the axial direction of the output shaft and is slidable against the pressing side sliding portion, and at least one of the pressing side sliding portion and the weight side sliding portion is an inclined surface that is inclined with respect to the axial direction of the output shaft.

[0012] According to another clutch device of the present invention, the weight member has a flat surface that extends in a direction intersecting the axial direction of the output shaft and is slidable relative to the retaining member. Because the weight member itself slides against the retaining member via the flat surface, vibrations occurring in the centrifugal clutch mechanism during starting can be suppressed. In other words, a decrease in ride comfort during starting can be suppressed. Furthermore, the weight member has, in addition to the flat surface that is slidable relative to the retaining member, a weight-side sliding portion that is slidable relative to the pressing-side sliding portion of the pressing member. Because the weight member itself is slidable relative to the retaining member and the pressing member, the clutch device can be manufactured easily with a small number of parts and at low cost.

[0013] According to the present invention, it is possible to provide a clutch device in which deterioration of ride comfort at start-up is suppressed.

[0014] FIG. 1 is a cross-sectional view of a clutch device according to the first embodiment. FIG. 2 is a perspective view of a first clutch center according to the first embodiment. FIG. 3 is a perspective view of the first clutch center according to the first embodiment. FIG. 4 is a perspective view of a second clutch center according to the first embodiment. FIG. 5 is a plan view of the second clutch center according to the first embodiment. FIG. 6 is a perspective view of a pressure member according to the first embodiment. FIG. 7 is a perspective view of a pressure member according to the first embodiment. FIG. 8A is a schematic view illustrating the functions of a center-side assist cam surface and a pressure-side assist cam surface. FIG. 8B is a schematic view illustrating the functions of a center-side slipper cam surface and a pressure-side slipper cam surface. FIG. 9A is a perspective view of a portion of a centrifugal clutch mechanism according to the first embodiment, and is a plan view illustrating a state in which a weight member is positioned radially inward. FIG. 9B is a plan view of a portion of a centrifugal clutch mechanism according to the first embodiment, and is a plan view illustrating a state in which a weight member is positioned radially inward. FIG. 10 is a plan view of a retaining member according to the first embodiment. FIG. 11 is a perspective view of a retaining member according to the first embodiment. FIG. 12 is an enlarged plan view showing a portion of a retaining member according to the first embodiment. FIG. 13 is a perspective view showing a weight member according to the first embodiment. FIG. 14 is a plan view showing a weight member according to the first embodiment. FIG. 15 is a perspective view showing a weight member according to the first embodiment. FIG. 16 is a bottom view showing a weight member according to the first embodiment. FIG. 17 is a side view showing a weight member according to the first embodiment. FIG. 18 is a plan view showing a portion of a centrifugal clutch mechanism according to the first embodiment, showing a state in which the weight member is positioned radially outward. FIG. 19 is an enlarged plan view showing a state in which the weight member is positioned radially outward. FIG. 20 is a cross-sectional view showing a portion of a clutch device according to the first embodiment, showing a state in which the weight member is positioned radially inward. FIG. 21 is a cross-sectional view showing a portion of a clutch device according to the first embodiment, showing a state in which the weight member is positioned radially outward. FIG. 22 is a cross-sectional view of a clutch device according to a second embodiment. FIG. 23 is a perspective view showing a retaining member according to the second embodiment. FIG. 24 is a perspective view showing a weight member according to the second embodiment.FIG. 25 is a bottom view showing a weight member according to the second embodiment. FIG. 26 is a side view showing a weight member according to the second embodiment. FIG. 27 is a cross-sectional view showing a portion of the clutch device according to the second embodiment, showing a state in which the weight member is positioned radially inward. FIG. 28 is a cross-sectional view showing a portion of the clutch device according to the second embodiment, showing a state in which the weight member is positioned radially outward. FIG. 29 is a plan view showing a portion of the centrifugal clutch mechanism according to the second embodiment, showing a state in which the weight member is positioned radially inward. FIG. 30 is a plan view showing a portion of the centrifugal clutch mechanism according to the second embodiment, showing a state in which the weight member is positioned radially outward. FIG. 31 is an enlarged plan view showing a state in which the weight member of the clutch device according to the third embodiment is positioned radially inward.

[0015] Hereinafter, an embodiment of a clutch device according to the present invention will be described with reference to the drawings. It should be noted that the embodiment described here is not intended to limit the present invention in any way. Furthermore, the same reference numerals are used to designate components and parts that perform the same functions, and redundant descriptions will be omitted or simplified as appropriate.

[0016] <First embodiment> Fig. 1 is a cross-sectional view of a clutch device 10 according to this embodiment. The clutch device 10 is provided, for example, in a saddle-ride type vehicle such as a motorcycle. The clutch device 10 is a device that transmits or cuts off the rotational driving force of an input shaft (crankshaft) of an engine, which is an example of a driving source of the motorcycle, to an output shaft 15. The clutch device 10 is a device that transmits or cuts 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 the engine and a transmission.

[0017] In the following description, the direction in which the pressure member 70 of the clutch device 10 approaches and moves away from the clutch center 40 is referred to as direction D, the direction in which the pressure member 70 approaches the clutch center 40 is referred to as a first direction D1, and the direction in which the pressure member 70 moves away from the clutch center 40 is referred to as a second direction D2. The circumferential direction (i.e., the rotational direction) of the clutch center 40 and the pressure member 70 is referred to as a circumferential direction S, the direction from one center-side cam portion 60 to the other center-side cam portion 60 with respect to the circumferential direction S (the direction from one pressure-side cam portion 90 to the other pressure-side cam portion 90) is referred to as a first circumferential direction S1 (see FIG. 2), and the direction from the other center-side cam portion 60 to one center-side cam portion 60 (the direction from the other pressure-side cam portion 90 to one pressure-side cam portion 90) is referred to as a second circumferential direction S2 (see FIG. 2). The radial direction of the output shaft 15 is referred to as the radial direction M, the direction away from the output shaft 15 as the outer side M1 (see FIG. 20), and the direction toward the output shaft 15 as the inner side M2 ​​(see FIG. 20). In this embodiment, the axial direction of the output shaft 15 is the same as direction D. The pressure member 70 and the clutch center 40 rotate in a first circumferential direction S1 (i.e., the direction from the center-side assist cam surface 60A of one center-side cam portion 60 toward the center-side slipper cam surface 60S). However, the above directions are merely defined for the convenience of explanation and do not limit the installation mode of the clutch device 10 or the present invention in any way.

[0018] 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.

[0019] As shown in Figure 1, the output shaft 15 is a hollow shaft body. One end of the output shaft 15 rotatably supports an input gear 35 and a clutch housing 30 (described later) via a needle bearing 28A. The output shaft 15 fixedly supports a 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.

[0020] As shown in Figure 1, the output shaft 15 has a main body 15A extending in direction D. The main body 15A has an oil flow path 15H therein through which clutch oil flows. The oil flow path 15H is formed between the main body 15A and a sleeve 16C that fits onto the outside of a push rod 16A (described later). The clutch oil flows inside the output shaft 15, i.e., through the oil flow path 15H of the main body 15A.

[0021] As shown in FIG. 1 , the oil flow path 15H of the output shaft 15 includes a push rod 16A and a push member 16B adjacent to the push rod 16A. The push rod 16A and the push member 16B are slidably disposed within a sleeve 16C. One end (the left end in the figure) of the push rod 16A is connected to a clutch operating lever (not shown) of the motorcycle. When the clutch operating lever is operated, the push rod 16A slides within the sleeve 16C and presses the push member 16B in the second direction D2. A portion of the push member 16B protrudes outward from the output shaft 15 (in this case, in the second direction D2) and is connected to a release bearing 18 provided on the pressure member 70. The sleeve 16C and the push member 16B are formed narrower than the inner diameter of the main body 15A, ensuring the flow of clutch oil within the oil flow path 15H.

[0022] The clutch housing 30 is formed by aluminum die-casting. The clutch housing 30 is formed in a cylindrical shape with a bottom. As shown in Figure 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.

[0023] As shown in Figure 1, an input gear 35 is provided on the bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by a rivet 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates when the input shaft of the engine is rotated. The input gear 35 rotates integrally with the clutch housing 30, independently of the output shaft 15.

[0024] 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 of the clutch housing 30 (i.e., direction D). The input side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0025] 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 material (not shown) made of multiple pieces of paper is attached to the front and back surfaces of the input side rotating plate 20. Grooves several hundred microns deep are formed between the friction material to retain clutch oil.

[0026] As shown in FIG. 1 , the clutch center 40 is accommodated 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 and the input side rotating plates 20 are arranged alternately in direction D. The clutch center 40 is driven to rotate 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 outside M1 of the first clutch center 41 in the radial direction M. The second clutch center 51 is fitted onto the first clutch center 41.

[0027] As shown in Figure 2, the first clutch center 41 includes an output shaft holding portion 42, an annular base wall 43 located on the outer side M1 of the output shaft holding portion 42 in the radial direction M, and a plurality of center side cam portions 60.

[0028] As shown in Fig. 1, the output shaft 15 is connected to the output shaft holding portion 42. 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 to penetrate the output shaft holding portion 42. A plurality of fitting teeth 47 extending in the axial direction of the output shaft 15 (i.e., direction D) are formed on an inner wall 45A of the output shaft holding portion 42 that defines the insertion hole 45. The fitting teeth 47 fit with the output shaft 15.

[0029] The center-side cam portion 60 is formed in a platform shape with a cam surface made up of an inclined surface that constitutes an Assist & Slipper (registered trademark) mechanism that generates an assist torque, which is a force that increases the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22, or a slipper torque, which is a force that decreases the pressing force (contact force) between the input-side rotating plate 20 and the output-side rotating plate 22, thereby transitioning to a partial clutch state. The partial clutch state is a state between a fully engaged state of the clutch (i.e., a state in which the input-side rotating plate 20 and the output-side rotating plate 22 are pressed against each other) and a fully disengaged state of the clutch (i.e., a state in which 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 to protrude in the second direction D2 from a 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 this 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.

[0030] As shown in FIG. 2 , the center-side cam portion 60 is located on the outer side M1 of the output shaft holder 42 in the radial direction M. 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. The center-side assist cam surface 60A is configured to generate a force (here, a first direction D1) that moves the pressure member 70 toward the clutch center 40 when the pressure member 70 rotates relative to the pressure member 70 during acceleration or other such events in order to increase the pressing force (pressure contact force) between the input side rotating plate 20 and the output side rotating plate 22. In this embodiment, when the force is generated, the position of the pressure member 70 relative to the clutch center 40 does not change, and the pressure member 70 does not need to physically approach the clutch center 40. Note that the pressure member 70 may be physically displaced relative to the clutch center 40. The center-side slipper cam surface 60S is configured to move the pressure member 70 away from the clutch center 40 when it rotates relative to the pressure member 70 during deceleration, etc., in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22. In the center-side cam portions 60 adjacent to each other 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 opposite each other in the circumferential direction S.

[0031] As shown in FIG. 2 , the first clutch center 41 has multiple boss portions 62 (three in this embodiment). The boss portions 62 are components that indirectly hold the pressure member 70. The multiple boss portions 62 are arranged at equal intervals in the circumferential direction S. The boss portions 62 are formed in a cylindrical shape. The boss portions 62 are located outwardly M1 in the radial direction M from the output shaft holding portion 42. The boss portions 62 extend toward the pressure member 70 (i.e., toward the second direction D2). The boss portions 62 are provided on the center-side cam portion 60. The boss portions 62 are provided between the center-side assist cam surface 60A and the center-side slipper cam surface 60S in the circumferential direction S. A threaded hole 62H is formed in the boss portion 62, into which the bolt 28 (see FIG. 1 ) is inserted. The threaded hole 62H extends in the axial direction of the clutch center 40 (i.e., in the direction D).

[0032] 2 and 3, the first clutch center 41 has a center-side cam hole 43H that penetrates a portion of the base wall 43. The center-side cam hole 43H penetrates the base wall 43 in 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 located between adjacent center-side cam portions 60 in the circumferential direction S. When viewed axially of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0033] 2, the first clutch center 41 has a plurality of engagement grooves 49. The engagement grooves 49 are formed in 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 an inner side M2 ​​in the radial direction M.

[0034] 4, the second clutch center 51 includes an annular outer peripheral wall 52, a flange 68 extending from the outer peripheral wall 52 toward the outside M1 in the radial direction M, and a center-side fitting portion 54. The second clutch center 51 holds an input side rotating plate 20 and a plurality of output side rotating plates 22 arranged alternately 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 plate 22.

[0035] 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 has a plurality of center-side fitting teeth 57 extending along the outer peripheral surface of the outer peripheral wall 52 in the axial direction of the second clutch center 51 (i.e., direction D), a plurality of spline grooves 58 formed between adjacent center-side fitting teeth 57 and extending in the axial direction of the second clutch center 51 (i.e., direction D), and an oil discharge hole 59. The center-side fitting teeth 57 hold the output-side rotating plate 22. The center-side fitting teeth 57 are aligned in the circumferential direction S. The center-side fitting teeth 57 are formed at equal intervals in the circumferential direction S. The center-side fitting teeth 57 are formed with the same shape. The center-side fitting teeth 57 protrude from the outer peripheral surface of the outer peripheral wall 52 to the outside M1 in the radial direction M. The oil discharge hole 59 is formed to penetrate the outer peripheral wall 52 in the radial direction M. The oil discharge holes 59 are formed between adjacent center-side fitting teeth 57. That is, the oil discharge holes 59 are formed in the spline grooves 58. The oil discharge holes 59 are formed in the center-side fitting portion 54. The oil discharge holes 59 communicate between the inside and outside of the second clutch center 51. The oil discharge holes 59 are holes that discharge clutch oil and the like that has flowed into the clutch center 40 from the output shaft 15 to the outside of the clutch center 40. The clutch oil discharged from the oil discharge holes 59 is supplied to the input-side rotating plate 20 and the output-side rotating plate 22 that are located on the outside M1 of the oil discharge holes 59 in the radial direction M.

[0036] The output side rotating plate 22 is held by the spline fitting portion 56 of the second clutch center 51 and the pressure member 70. A portion of the output side rotating plate 22 is held by the center side fitting teeth 57 and the spline grooves 58 of the second clutch center 51 through spline fitting. Another portion of the output side rotating plate 22 is held by pressure side fitting teeth 87 (see FIG. 6 ) of the pressure member 70, which will be described later. The output side rotating plate 22 is provided so as to be displaceable along the axial direction of the clutch center 40 (i.e., direction D). 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 of the pressure member 70 (i.e., direction D). The output side rotating plate 22 is provided so as to be rotatable integrally with the pressure member 70.

[0037] 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 out an SPCC thin plate into an annular shape. 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 both the input side rotating plate 20 and the output side rotating plate 22.

[0038] As shown in Figure 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 slidably fit onto a pressure-side fitting portion 88 (see Figure 6), which will be 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 end 15T (see Figure 1) of the output shaft 15 relative to the pressure-side fitting portion 88. In other words, a gap is formed between the center-side fitting portion 54 and the pressure-side fitting portion 88.

[0039] 4 and 5, the second clutch center 51 has a plurality of engagement protrusions 55. The engagement protrusions 55 engage with the engagement grooves 49 (see FIG. 2) of the first clutch center 41. The engagement protrusions 55 are formed on the inner circumferential surface of the outer circumferential wall 52. The engagement protrusions 55 protrude from the inner circumferential surface of the outer circumferential wall 52 toward the inner side M2 ​​in the radial direction M.

[0040] As shown in FIG. 1 , the pressure member 70 is provided so as to be able to move toward or away from the clutch center 40. The pressure member 70 is provided so as to be able to rotate relatively to the clutch center 40. The pressure member 70 is configured so as 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 into the second clutch center 51, thereby positioning the pressure member 70 in the radial direction M. The pressure member 70 is provided so as to be able to slide in direction D with respect to the first clutch center 41 and the second clutch center 51. The pressure member 70, the first clutch center 41, and the second clutch center 51 are configured so as to be able to rotate relatively to one another in the circumferential direction S. As shown in FIG. 6 , the pressure member 70 has a main body 72 and a flange 98 that connects to the outer peripheral edge of the main body 72 on the second direction D2 side and extends radially outward M1 in the radial direction M. The main body 72 protrudes in the first direction D1 beyond the flange 98. The flange 98 is located at the outer diameter end of the pressure member 70. The flange 98 is located radially outward M1 beyond a cylindrical portion 80 (see also FIG. 7 ), which will be described later. The pressure member 70 holds at least a portion of the input side rotating plates 20 and the multiple output side rotating plates 22 that are arranged alternately. The flange 98 is configured to be able to press against the input side rotating plates 20 and the output side rotating plates 22.

[0041] 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 (see FIG. 7).

[0042] 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 (see FIG. 1) of the output shaft 15. The cylindrical portion 80 accommodates the release bearing 18 (see FIG. 1). The cylindrical portion 80 is a portion that receives the pressing force from the push member 16B. The cylindrical portion 80 is a portion that receives the clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0043] As shown in FIG. 6 , the pressure-side cam portion 90 is formed in a platform shape having a cam surface made up 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 to protrude in the first direction D1 beyond 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 this 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.

[0044] As shown in FIG. 6 , the pressure-side cam portion 90 is located radially outwardly M1 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 able to contact the center-side assist cam surface 60A. The pressure-side assist cam surface 90A is configured to generate a force in a direction from the pressure member 70 toward the clutch center 40 (here, the first direction D1) to increase the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22 when the pressure member 70 rotates relative to the clutch center 40 during acceleration, etc. The pressure-side slipper cam surface 90S is configured to be able to contact the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to move the pressure member 70 away from the clutch center 40 when the pressure member 70 rotates relative to the clutch center 40 during deceleration or the like in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22. 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 opposite each other in the circumferential direction S.

[0045] Here, the action 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, a rotational force in the first circumferential direction S1 is applied to the pressure member 70, as shown in Figure 8A. Therefore, due to the action 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 in the pressure member 70, increasing the pressing force between the input-side rotating plate 20 and the output-side rotating plate 22.

[0046] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30 and back torque is generated, a rotational force in the first circumferential direction S1 is applied to the clutch center 40, as shown in Fig. 8B. Therefore, the action of the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S moves the pressure member 70 in the second direction D2, releasing the pressure contact force between the input-side rotating plate 20 and the output-side rotating plate 22. This makes it possible to avoid problems with the engine and transmission due to back torque.

[0047] 6, the pressure-side fitting portion 88 is located on the outer side M1 in the radial direction M of the pressure-side cam portion 90. The pressure-side fitting portion 88 is located on the second direction D2 side of the pressure-side cam portion 90. The pressure-side fitting portion 88 is configured to be slidably fitted into the center-side fitting portion 54 (see FIG. 4).

[0048] As shown in FIGS. 6 and 7 , the pressure member 70 has a pressure-side cam hole 83H that penetrates a portion of the main body 72 and the flange 98. The pressure-side cam hole 83H is located on the outer side M1 of the cylindrical portion 80 in the radial direction M. The pressure-side cam hole 83H extends in the radial direction M from a side of the cylindrical portion 80 to the outer side M1 of the pressure-side fitting portion 88 in the radial direction M. The pressure-side cam hole 83H is formed between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 90. When viewed in the axial direction of the pressure member 70, the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 83H overlap. 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 passes through the pressure-side cam hole 83H.

[0049] As shown in FIG. 6 , the pressure member 70 has a plurality of pressure-side fitting teeth 87 arranged on a flange 98. The pressure-side fitting teeth 87 hold at least a portion of the output-side rotating plate 22. The pressure-side fitting teeth 87 protrude from the flange 98 in a first direction D1. The pressure-side fitting teeth 87 are located on the outer side M1 of the cylindrical portion 80 in the radial direction M. The pressure-side fitting teeth 87 are located on the outer side M1 of the pressure-side cam portion 90 in the radial direction M. The pressure-side fitting teeth 87 are located on the outer side M1 of the pressure-side fitting portion 88 in the radial direction M. The plurality of pressure-side fitting teeth 87 are aligned 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, some of the pressure-side fitting teeth 87 have been removed, which increases the spacing between those portions, but the remaining adjacent pressure-side fitting teeth 87 are equally spaced. As shown in Fig. 1, the pressure-side fitting teeth 87 hold an end plate 21. The end plate 21 is a plate used to adjust the spacing in direction D between the input-side rotating plate 20 and the output-side rotating plate 22 (i.e., the spacing in the axial direction of the output shaft 15) when a weight member 130 (described later) of the centrifugal clutch mechanism 120 is located at a position M2 on the inside in the radial direction M.

[0050] As shown in Figure 7, the spring accommodating portion 84 is formed in the pressure-side cam portion 90. The spring accommodating portion 84 is located on the outer side M1 of the cylindrical portion 80 in the radial direction M. The spring accommodating portion 84 is formed so as to be recessed from the second direction D2 to the first direction D1. The spring accommodating portion 84 is formed in a circular shape. The spring accommodating portion 84 accommodates the clutch spring 25.

[0051] As shown in FIG. 1 , the clutch spring 25 is housed in the spring housing 84. An end 25D1 of the clutch spring 25 in the first direction D1 abuts against the pressure member 70. An end 25D2 of the clutch spring 25 in the second direction D2 abuts against the stopper plate 100. The clutch spring 25 biases the pressure member 70 toward the clutch center 40 (i.e., toward the first direction D1). The clutch spring 25 is, for example, a coil spring made of spring steel wound in a spiral shape. The clutch spring 25 extends in the direction D.

[0052] 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 of the clutch center 40. The centrifugal clutch mechanism 120 is held in the clutch housing 30. The centrifugal clutch mechanism 120 is provided 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 pressure contact member 150 (see FIG. 1 ), a spring 160 (see also FIG. 9B ), and a contact member 170 (see also FIG. 1 ). When the weight members 130 are at a position PO on the outer side M1 in the radial direction M (see FIGS. 1 and 21 ), the centrifugal clutch mechanism 120 presses the input side rotating plate 20 and the output side rotating plate 22 together, thereby enabling transmission of the rotational driving force of the input shaft to the output shaft 15. When the weight member 130 is at a position PI on the inside M2 ​​in the radial direction M (see FIG. 20), the centrifugal clutch mechanism 120 releases the pressure contact force between the input side rotating plate 20 and the output side rotating plate 22, thereby enabling the transmission of the rotational driving force of the input shaft to the output shaft 15 to be blocked. The centrifugal clutch mechanism 120 is configured to be able to press the auxiliary clutch plate 180 (see FIG. 1).

[0053] As shown in Figure 9B, the holding member 140 holds the weight member 130 movably 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 (see Figure 18). The holding member 140 is formed in an annular shape. The holding member 140 is formed by aluminum die-casting. 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 Figure 1).

[0054] As shown in FIG. 10 , the main body 141 is formed in a ring shape. As shown in FIG. 12 , the main body 141 includes a thick portion 141T including a wall portion 141A and a protrusion 141B. The wall portion 141A is located between the engagement claw 143 and the accommodating recess 145 in the radial direction M. The protrusion 141B protrudes from the wall portion 141A toward an inner side M2 ​​in the radial direction M. The protrusion 141B defines a portion of the accommodating recess 145. An end portion 141BX of the protrusion 141B on the inner side M2 ​​in the radial direction M is located more inward in the radial direction M than an end portion 145X of the accommodating recess 145 on the outer side M1 in the radial direction M. As shown in FIG. 9B , the protrusion 141B is located between a first spring 161 and a second spring 162 (described later) in the circumferential direction S.

[0055] As shown in Figure 10, the engagement claws 143 protrude from the outer peripheral edge 141E of the main body 141 toward the outer side M1 in the radial direction M. The engagement claws 143 are formed integrally with the main body 141. The engagement claws 143 engage with the clutch housing 30 (see Figure 1). The multiple engagement claws 143 are aligned in the circumferential direction S. As shown in Figure 12, the engagement claws 143 have a head 143A and a root portion 143B located radially inward of the head 143A. The length LA of the head 143A in the circumferential direction S is longer than the length LB of the root portion 143B in the circumferential direction S.

[0056] As shown in FIG. 1 , the accommodating recess 145 is formed in the main body 141 so as to be recessed in the axial direction of the output shaft 15 (i.e., direction D). The accommodating recess 145 is recessed in a first direction D1. The accommodating recess 145 accommodates the weight member 130 so as to be movable in the radial direction M. The multiple accommodating recesses 145 are aligned in the circumferential direction S. As shown in FIGS. 10 and 11 , the accommodating recess 145 is provided with a sliding surface 145M along which the weight member 130 slides when the weight member 130 moves in the radial direction M. The accommodating recess 145 is formed with an accommodating groove 146 that accommodates a portion of the spring 160. The accommodating groove 146 extends in the radial direction M. The accommodating groove 146 includes a first accommodating groove 146A that accommodates a first spring 161 (described later) and a second accommodating groove 146B that accommodates a second spring 162. The first accommodating groove 146A is located closer to the first circumferential direction S1 than the protruding portion 141B. The second accommodating groove 146B is located closer to the second circumferential direction S2 than the protruding portion 141B. One end of each of the first spring 161 and the second spring 162 abuts against an end portion 145X on the outer side M1 in the radial direction M of the accommodating recess 145. As shown in FIG. 19 , the accommodating recess 145 is provided with a pressing surface 145H that is pressed by the weight member 130 when the weight member 130 is at a position PO on the outer side M1 in the radial direction M. A stress from the weight member 130 on the outer side M1 in the radial direction M is applied to the pressing surface 145H. The engaging claw 143 and the pressing surface 145H are positioned offset from each other in the circumferential direction S. Here, the engaging claw 143 is positioned between the pair of pressing surfaces 145H in the circumferential direction S. The accommodating recess 145 may be formed with a through-hole that penetrates the main body 141 in the axial direction of the output shaft 15 (i.e., direction D). In this case, the clutch oil flowing outside the holding member 140 flows into the accommodating recess 145 via the through-hole.

[0057] As shown in FIG. 12 , the length L1 of the protrusion 141B in the circumferential direction S is equal to or greater than the length L2 of the engagement claw 143 in the circumferential direction S. The length L3 in the radial direction M from the outer peripheral edge 141E of the main body 141 to the end 141BX of the protrusion 141B on the inner side M2 ​​in the radial direction M 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 of the engagement claw 143 on the outer side M1 in the radial direction M. The end 141BL in the first circumferential direction S1 of the protrusion 141B is located closer to the first circumferential direction S1 than the end 143AL in the first circumferential direction S1 of the engagement claw 143. Here, the end 143AL in the first circumferential direction S1 of the engagement claw 143 is the end of the head 143A in the first circumferential direction S1. An end 141BR of the protrusion 141B in the second circumferential direction S2 is located closer to the second circumferential direction S2 than an end 143AR of the engagement claw 143 in the second circumferential direction S2. Here, the end 143AR of the engagement claw 143 in the second circumferential direction S2 is the end of the head 143A in the second circumferential direction S2. Furthermore, an end 141BL of the protrusion 141B in the first circumferential direction S1 is located closer to the first circumferential direction S1 than an end 143BL of the root 143B in the first circumferential direction S1. An end 141BR of the protrusion 141B in the second circumferential direction S2 is located closer to the second circumferential direction S2 than an end 143BR of the root 143B in the second circumferential direction S2. The surfaces of the wall 141A, the protrusion 141B, and the engagement claw 143 facing the pressure contact member 150 are flush with each other.

[0058] As shown in FIG. 9B , the multiple weight members 130 are arranged in the circumferential direction S. The weight members 130 are configured to be movable from a position PI on the inner side M2 ​​in the radial direction M to a position on the outer side due to centrifugal force generated by 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 , when no centrifugal force is applied, the weight members 130 are held at a position PI on the inner side M2 ​​in the radial direction M by a spring 160 (see FIG. 9B ). As shown in FIG. 21 , when centrifugal force is applied, the weight members 130 move toward the outer side M1 in the radial direction M against the biasing force of the spring 160, and move to a position PO on the outer side M1 in the radial direction M. At this time, as shown in FIG. 19 , the weight member 130 presses the pressing surface 145H of the accommodation recess 145, but does not come into contact with the protrusion 141B of the holding member 140. The weight member 130 is accommodated in the accommodation recess 145 of the holding member 140. As shown in FIG. 15 , the weight member 130 includes a biasing member holding portion 131, a first flat surface 133 provided on one side of the biasing member holding portion 131 in the circumferential direction S, a second flat surface 135 provided on the other side of the biasing member holding portion 131 in the circumferential direction S, and a weight-side inclined surface 130F (see FIG. 13 ) located on the opposite side of the first flat surface 133 and the second flat surface 135 in the axial direction of the output shaft 15 (i.e., direction D). The weight-side inclined surface 130F is an example of a weight-side sliding portion.

[0059] The biasing member holding portion 131 holds the spring 160. As shown in Fig. 15, the biasing member holding portion 131 is a recessed groove recessed from the first direction D1 to 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 of the spring 160 on the inner side M2 ​​in the radial direction M. In this embodiment, the biasing member holding portion 131 includes a first biasing member holding portion 131A that holds a first spring 161 (described later) and a second biasing member holding portion 131B that holds a second spring 162 (described later).

[0060] As shown in FIGS. 15 and 16 , the first flat surface 133 is provided closer to the first circumferential direction S1 than the biasing member holding portion 131. More specifically, the first flat surface 133 is provided closer to the first circumferential direction S1 than the first biasing member holding portion 131A. The first flat surface 133 is provided side by side with the first biasing member holding portion 131A in the circumferential direction. The second flat surface 135 is provided closer to the second circumferential direction S2 than the biasing member holding portion 131. More specifically, the second flat surface 135 is provided closer to the second circumferential direction S2 than the second biasing member holding portion 131B. The second flat surface 135 is provided side by side with the second biasing member holding portion 131B in the circumferential direction. As shown in FIG. 17 , the first plane 133 and the second plane 135 are planes that extend in a direction intersecting the axial direction of the output shaft 15 (i.e., direction D) (for example, a direction inclined at an angle of 80° to 90° with respect to the axial direction of the output shaft 15; for example, a direction perpendicular to the axial direction of the output shaft 15). The first plane 133 and the second plane 135 are formed flush with each other. The first plane 133 and the second plane 135 are provided to be slidable relative to the holding member 140. More specifically, the first plane 133 and the second plane 135 are provided to be slidable relative to a sliding surface 145M of the accommodating recess 145. As shown in FIG. 16 , an end 133A on the inner side M2 ​​of the first plane 133 in the radial direction M and an end 135A on the inner side M2 ​​of the second plane 135 in the radial direction M are located inward M2 of the holding wall 132 in the radial direction M.

[0061] As shown in FIG. 15 , the weight member 130 includes a third flat surface 137. The third flat surface 137 is located between the first flat surface 133 and the second flat surface 135 in the circumferential direction S. The third flat surface 137 is located between the first biasing member holding portion 131A and the second biasing member holding portion 131B in the circumferential direction S. The third flat surface 137 extends in a direction intersecting the axial direction of the output shaft 15 (i.e., direction D) (for example, a direction inclined at an angle of 80° to 90° with respect to the axial direction of the output shaft 15; for example, a direction perpendicular to the axial direction of the output shaft 15). The third flat surface 137 may be provided to be slidable relative to the holding member 140. The third flat surface 137 may be formed flush with the first flat surface 133 and the second flat surface 135.

[0062] The weight-side inclined surface 130F is provided so as to be able to come into contact with the pressing member 150. As shown in Figure 17, the weight-side inclined surface 130F is inclined with respect to the axial direction of the output shaft 15 (i.e., direction D). The weight-side inclined surface 130F is inclined so as to face in a first direction D1 from an inner side M2 ​​in the radial direction M to an outer side M1 in the radial direction M. The weight-side inclined surface 130F is configured so as to be able to slide against a later-described pressing-side inclined surface 150F (see Figure 20) of the pressing member 150.

[0063] As shown in FIG. 17 , an end portion 133B on the outer side M1 of the first flat surface 133 and an end portion 135B on the outer side M1 of the second flat surface 135 are located further outward in the radial direction M than an end portion 130FA on the inner side M2 ​​of the weight-side inclined surface 130F. An end portion 133A on the inner side M2 ​​of the first flat surface 133 and an end portion 135A on the inner side M2 ​​of the second flat surface 135 are located further inward in the radial direction M than an end portion 130FA on the inner side M2 ​​of the weight-side inclined surface 130F. A length L5 in the radial direction M of the first flat surface 133 and the second flat surface 135 is longer than a length L6 in the radial direction M of the weight-side inclined surface 130F. The total area of ​​the first flat surface 133 and the second flat surface 135 is greater than the area of ​​the weight-side inclined surface 130F. The length L7 (see Figure 16) in the circumferential direction S from the end 133S1 in the first circumferential direction S1 of the first plane 133 to the end 135S2 in the second circumferential direction S2 of the second plane 135 is longer than the length L8 (see Figure 14) in the circumferential direction S of the weight-side inclined surface 130F.

[0064] As shown in FIG. 9B , the spring 160 is disposed on the outer side M1 of the weight member 130 in the radial direction M. The spring 160 is an example of a biasing member. The spring 160 is provided in the holding member 140. The spring 160 is housed in the housing recess 145 of the holding member 140. More specifically, a portion of the spring 160 is housed in the housing groove 146 (see FIG. 10 ). A portion of the spring 160 is located inside the weight member 130. That is, a portion of the spring 160 is located in 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 side by side 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 in the circumferential direction S.

[0065] 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 sandwiched between them in the axial direction (direction D in this case) of the output shaft 15. As shown in FIG. 9A , the contact member 170 is formed in a disk 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 bolts 172 into bolt holes 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 bolts 172. Instead of the bolts 172, the contact member 170 may be fixed to the holding member 140 by other fixing means, such as rivets. The contact member 170 comes into contact with the weight member 130. The contact member 170 is a member that prevents the weight member 130 from moving in the second direction D2. The contact member 170 has a plurality of openings 170H that are aligned in the circumferential direction S. The weight-side inclined surface 130F of the weight member 130 is exposed to the outside through the openings 170H. A portion of the weight member 130 (e.g., the weight-side inclined surface 130F) protrudes further toward the opposite side of the holding member 140 (here, the second direction D2 side) in the axial direction of the output shaft 15 (here, direction D) than the contact member 170 that is fixed to the opening of the holding member 140.

[0066] The pressing member 150 is configured to be able to move in the axial direction of the output shaft 15 (here, in the second direction D2) as the weight member 130 moves from a position PI on the inner side M2 ​​in the radial direction M to a position PO on the outer side M1, thereby pressing the input side rotating plate 20 and the output side rotating plate 22 together. The pressing member 150 is formed in an annular shape. As shown in FIG. 1 , the pressing member 150 has a pressing-side inclined surface 150F and a pressing surface 150P. The pressing-side inclined surface 150F is an example of a pressing-side sliding portion. The pressing-side inclined surface 150F is provided so as to be able to come into contact with the weight member 130. The pressing-side inclined surface 150F is inclined with respect to the axial direction of the output shaft 15 (i.e., direction D). The pressing-side inclined surface 150F is inclined in a first direction D1 from the inner side M2 ​​in the radial direction M toward the outer side M1 in the radial direction M. The pressure-side inclined surface 150F is configured to be slidable relative to the weight-side inclined surface 130F of the weight member 130. As shown in FIG. 21 , in a cross-sectional view taken along a plane including the axial direction (i.e., direction D) and radial direction M of the output shaft 15, a straight line CL1 passing through a center 150FC of the pressure-side inclined surface 150F in the radial direction M and parallel to the axial direction (i.e., direction D) of the output shaft 15 passes through the first flat surface 133 and the second flat surface 135 when the weight member 130 is positioned on the outer side M1 in the radial direction M. A plurality of pressure-side inclined surfaces 150F are provided for each weight member 130 along the circumferential direction S. When the clutch housing 30 rotates and centrifugal force is applied to the weight member 130, the weight member 130 moves along the pressure-side inclined surface 150F, causing the pressure member 150 to move in a direction away from the holding member 140 (i.e., the second direction D2). As a result, the pressing surface 150P of the pressure contact member 150 presses the flange 68 of the second clutch center 51 in the second direction D2. The pressure contact member 150 has a plurality of engaging protrusions 153 formed in the circumferential direction S. 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 pressure contact member 150 are held in the clutch housing 30 by spline fitting. The holding member 140 and the pressure contact member 150 are provided so as to be displaceable along the axial direction of the clutch housing 30 (i.e., 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 .

[0067] 9A and 20 , when no centrifugal force is applied to the weight member 130, the weight member 130 is held at 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. 18 and 21 , when centrifugal force is applied to the weight member 130, the weight member 130 moves from position PI on the inner side M2 ​​to position PO on the outer side M1 in the radial direction M. When the weight member 130 moves in the radial direction M, the weight-side inclined surface 130F of the weight member 130 slides against the pressing-side inclined surface 150F of the pressing member 150, and the first flat surface 133 and the second flat surface 135 of the weight member 130 slide against the sliding surface 145M of the holding member 140. At this time, the pressing surface 150P of the pressing 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, bringing them into a pressed state, and the rotational driving force of the input shaft becomes capable of being 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.

[0068] As shown in Fig. 1, the auxiliary clutch plate 180 is provided inside the clutch housing 30. The auxiliary clutch plate 180 is fixed to the output shaft 15. An insertion hole 152H is formed in the auxiliary clutch plate 180, into which the output shaft 15 is inserted and spline-fitted. The auxiliary clutch plate 180 is disposed closer to the first direction D1 than a portion of the centrifugal clutch mechanism 120. The auxiliary clutch plate 180 is adjacent to the first clutch center 41.

[0069] 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 with each other (i.e., when the weight member 130 of the centrifugal clutch mechanism 120 is located at position PO on the outer side M1 in the radial direction M), thereby enabling the rotational driving force of the input shaft to be transmitted to the output shaft 15. The auxiliary clutch plate 180 is configured to be released from the pressure of 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 (i.e., when the weight member 130 is located at position PI on the inner side M2 ​​in the radial direction M), thereby blocking the transmission of the rotational driving force of the input shaft to the output shaft 15.

[0070] As shown in Fig. 1, the stopper plate 100 is provided so as to be able to come into contact with the pressure member 70. The stopper plate 100 is a member that prevents the pressure member 70 from moving away from the clutch center 40 by more than a predetermined distance in the second direction D2. The stopper plate 100 is fixed to the boss portion 62 of the first clutch center 41 by the bolt 28. With the clutch spring 25 disposed in the spring accommodating portion 84, the pressure member 70 is fixed to the clutch center 40 by tightening the bolt 28 to the boss portion 62 via the stopper plate 100. The stopper plate 100 is formed in a ring shape in a plan view.

[0071] As described above, in the clutch device 10 of this embodiment, the weight member 130 includes the first flat surface 133 and the second flat surface 135, which are flat surfaces extending in a direction intersecting the axial direction of the output shaft 15 (i.e., direction D) and are slidable relative to the retaining member 140. Because the weight member 130 itself slides against the retaining member 140 via two flat surfaces (i.e., the first flat surface 133 and the second flat surface 135), vibrations occurring in the centrifugal clutch mechanism 120 during starting can be suppressed. This means that a decrease in ride comfort during starting can be suppressed. Furthermore, the weight member 130 includes the weight-side inclined surface 130F, which is slidable relative to the pressure-contact-side inclined surface 150F of the pressure-contact member 150, in addition to the first flat surface 133 and the second flat surface 135, which are slidable relative to the retaining member 140. In this way, since the weight member 130 itself is slidable relative to the holding member 140 and the pressing member 150, the clutch device 10 can be manufactured easily at low cost with a small number of parts.

[0072] In the clutch device 10 of this embodiment, an end portion 133A of the first flat surface 133 on the inner side M2 ​​in the radial direction M and an end portion 135A of the second flat surface 135 on the inner side M2 ​​in the radial direction M are located on the inner side M2 ​​in the radial direction M than the retaining wall 132. According to the above aspect, the first flat surface 133 and the second flat surface 135 are relatively large, so that the contact area with the retaining member 140 can be increased.

[0073] In the clutch device 10 of this embodiment, the ends 133B, 135B of the first flat surface 133 and the second flat surface 135 on the outer side M1 in the radial direction M are located on the outer side M1 in the radial direction M of the end 130FA of the weight-side inclined surface 130F on the inner side M2 ​​in the radial direction M, and the ends 133A, 135A of the first flat surface 133 and the second flat surface 135 on the inner side M2 ​​in the radial direction M are located on the inner side M2 ​​in the radial direction M of the weight-side inclined surface 130F. According to the above aspect, the first flat surface 133 and the second flat surface 135 are relatively large, so that the contact area with the retaining member 140 can be increased.

[0074] In the clutch device 10 of this embodiment, the length L5 of the first flat surface 133 and the second flat surface 135 in the radial direction M is longer than the length L6 of the weight-side inclined surface 130F in the radial direction M. According to the above aspect, since the first flat surface 133 and the second flat surface 135 are relatively large, the contact area with the retaining member 140 can be increased.

[0075] In the clutch device 10 of this embodiment, the total area of ​​the first flat surface 133 and the second flat surface 135 is larger than the area of ​​the weight-side inclined surface 130F. According to the above aspect, since the first flat surface 133 and the second flat surface 135 are relatively large, the contact area with the retaining member 140 can be increased.

[0076] In the clutch device 10 of this embodiment, the length L7 in the circumferential direction S from the end 133S2 of the first flat surface 133 in the second circumferential direction S2 to the end 135S1 of the second flat surface 135 in the first circumferential direction S1 is longer than the length L8 in the circumferential direction S of the weight-side inclined surface 130F. According to the above aspect, the first flat surface 133 and the second flat surface 135 are relatively large, so that the contact area with the retaining member 140 can be increased.

[0077] The clutch device 10 of this embodiment includes a plurality of springs 160 between the first plane 133 and the second plane 135 in the circumferential direction S. According to the above aspect, the weight member 130 itself can slide more effectively on the retaining member 140 via the first plane 133 and the second plane 135.

[0078] In the clutch device 10 of this embodiment, in a cross-sectional view taken along a plane including the axial direction (i.e., direction D) and the radial direction M of the output shaft 15, a straight line CL1 that passes through the center 150FC of the pressure-contact-side inclined surface 150F in the radial direction M and is parallel to the axial direction of the output shaft 15 passes through the first flat surface 133 and the second flat surface 135 when the weight member 130 is positioned on the outer side M1 in the radial direction M. According to the above aspect, the first flat surface 133 and the second flat surface 135 are relatively large, and therefore the contact area with the retaining member 140 can be increased.

[0079] 22 , a centrifugal clutch mechanism 220 according to the second embodiment includes a plurality of weight members 230, a holding member 240, a pressure contact 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 includes weight members 230 instead of weight members 130, holds holding members 240 instead of holding members 140, and further includes a cylindrical member 270.

[0080] As shown in Figures 22 and 23, the holding member 240 includes a holding member-side guide portion 245 that accommodates a portion of the cylindrical member 270. The holding member-side guide portion 245 is formed on a surface 245M of the accommodating recess 145 that faces the weight member 230. The holding member-side guide portion 245 holds the cylindrical member 270 so that a portion of the cylindrical member 270 protrudes from the surface 245M of the holding member 240 that faces the weight member 230 toward the weight member 230 (i.e., toward the second direction D2). The holding member-side guide portion 245 guides movement of the cylindrical member 270 in the radial direction M. The holding member-side guide portion 245 is located between the first accommodating groove 146A and the second accommodating groove 146B in the circumferential direction S. The holding member-side guide portion 245 is rectangular in plan view. The holding member side guide portion 245 is configured to restrict the cylindrical member 270 from moving in the circumferential direction S, and also restrict the cylindrical member 270 from moving in the radial direction M more than a predetermined distance.

[0081] As shown in FIG. 24 , the weight member 230 includes a guide portion 238 that accommodates a portion of the cylindrical member 270. The guide portion 238 is formed on a surface (here, the third flat surface 137) facing the holding member 240. The guide portion 238 holds the cylindrical member 270 so that a portion of the cylindrical member 270 protrudes from the surface (here, the third flat surface 137) of the weight member 230 facing the holding member 240 toward the holding member 240 (i.e., toward 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 a plan view. The guide portion 238 includes a first restricting portion 238S that restricts movement of the cylindrical member 270 in the circumferential direction S and a second restricting portion 238M that restricts movement of the cylindrical member 270 in the radial direction M beyond a predetermined distance. 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 an accommodation groove 238P that is recessed in a direction from the retaining member 240 toward the weight member 230 (i.e., the second direction D2) with respect to the axial direction of the output shaft 15 (i.e., direction D) and accommodates a portion of the cylindrical member 270. The accommodation groove 238P is defined by the first restricting portion 238S and the second restricting portion 238M.

[0082] As shown in FIG. 22 , the cylindrical member 270 is provided between the weight member 230 and the holding member 240 in the axial direction of the output shaft 15 (i.e., direction D). The cylindrical member 270 is disposed to extend in a direction intersecting the radial direction M (here, a direction perpendicular to the radial direction M and direction D). The cylindrical member 270 rolls relative to the weight member 230 and the holding member 240. A portion of the cylindrical member 270 is housed in the holding member-side guide portion 245 of the holding member 240, and another portion of the cylindrical member 270 is housed in the guide portion 238 of the weight member 230. The cylindrical member 270 rolls relative to the holding member-side guide portion 245 and the guide portion 238. As shown in FIG. 25 , the cylindrical member 270 is located between the first spring 161 and the second spring 162 in 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.

[0083] 27 , in a cross-sectional view taken along 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 positioned on the inner side M2 ​​in the radial direction M, at least a portion of the cylindrical member 270 overlaps with the spring 160. In this case, the entire cylindrical member 270 overlaps with the spring 160. In a cross-sectional view taken along 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 positioned on the inner side M2 ​​in the radial direction M, at least a portion of the guide portion 238 overlaps with the spring 160. In this case, the entire guide portion 238 overlaps with the spring 160.

[0084] As shown in Figure 28 , in a cross-sectional view taken along a plane including the axial direction (i.e., direction D) and radial direction M of the output shaft 15, a straight line CL2 passing through the center 150FC of the pressure-contact-side inclined surface 150F in the radial direction M 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 positioned on the outer side M1 in the radial direction M. As shown in Figure 29 , when viewed from the axial direction (i.e., direction D) of the output shaft 15 with the weight member 230 positioned on the inner side M2 ​​in the radial direction M, at least a portion of the weight-side inclined surface 130F overlaps with the holding member-side guide portion 245. As shown in Figure 30 , when viewed from the axial direction (i.e., direction D) of the output shaft 15 with the weight member 230 positioned on the outer side M1 in the radial direction M, at least a portion of the pressure-contact-side inclined surface 150F overlaps with the guide portion 238.

[0085] In this centrifugal clutch mechanism 220, as shown in Figures 27 and 29, when no centrifugal force is applied to the weight member 230, the weight member 230 is held at position PI on the inner side M2 ​​in the radial direction M, and the pressure contact force between the input side rotating plate 20 and the output side rotating plate 22 is released. On the other hand, as shown in Figures 28 and 30, when centrifugal force is applied to the weight member 230, the weight member 230 moves from position PI on the inner side M2 ​​in the radial direction M to position PO on the outer side M1. When the weight member 230 moves in the radial direction M, the cylindrical member 270 rolls relative to the weight member 230 and the holding member 240, guided by the guide portion 238 and the holding member side guide portion 245. At this time, the first flat surface 133 and the second flat surface 135 of the weight member 230 do not slide on the sliding surface 145M of the holding member 240.

[0086] According to the clutch device 10 of this embodiment, the weight member 230 includes a guide portion 238 that is formed on the third flat surface 137 facing the holding member 240, holds the cylindrical member 270 so that a portion of the cylindrical member 270 protrudes from the third flat surface 137 of the weight member 230 facing the holding member 240 toward the holding member 240, and guides the movement of the cylindrical member 270 in the radial direction M. Here, the cylindrical member 270 is rollable relative to the weight member 230 and the holding member 240, and is guided by the guide portion 238 so that only the cylindrical member 270 can move independently in the radial direction M, thereby suppressing the generation of vibration in the centrifugal clutch mechanism 120 when starting. In other words, a decrease in ride comfort when starting can be suppressed.

[0087] In the clutch device 10 of this embodiment, 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. According to the above aspect, the cylindrical member 270 can move smoothly in the radial direction M in the guide portion 238.

[0088] In the clutch device 10 of this embodiment, the guide portion 238 has an accommodation groove 238P that is recessed in a direction from the retaining member 240 toward the weight member 230 with respect to the axial direction of the output shaft 15 (i.e., direction D) and accommodates a portion of the cylindrical member 270. According to the above aspect, the cylindrical member 270 can move smoothly in the radial direction M in the guide portion 238.

[0089] In the clutch device 10 of this embodiment, the first restricting portion 238S and the second restricting portion 238M define the accommodation groove 238P. According to the above aspect, it is possible to easily restrict the movement of the cylindrical member 270 in a predetermined direction and accommodate the cylindrical member 270.

[0090] In the clutch device 10 of this embodiment, when viewed in cross section on a plane including the axial direction (i.e., direction D) and radial direction M of the output shaft 15, when the weight member 230 is positioned on the inner side M2 ​​in the radial direction M, at least a portion of the cylindrical member 270 overlaps with the spring 160. According to the above aspect, the cylindrical member 270 can be arranged compactly in the axial direction of the output shaft 15.

[0091] In the clutch device 10 of this embodiment, the cylindrical member 270 is located between the first spring 161 and the second spring 162 in the circumferential direction S. According to the above aspect, the cylindrical member 270 can be arranged compactly in the circumferential direction S.

[0092] In the clutch device 10 of this embodiment, when the weight member 230 is positioned on the inner side M2 ​​in the radial direction M in a cross-sectional view taken along a plane including the axial direction (i.e., direction D) of the output shaft 15 and the radial direction M, at least a portion of the guide portion 238 overlaps with the spring 160. According to the above aspect, the cylindrical member 270 can be arranged compactly in the axial direction of the output shaft 15.

[0093] In the clutch device 10 of this embodiment, in a cross-sectional view taken along a plane including the axial direction (i.e., direction D) and the radial direction M of the output shaft 15, a straight line LC2 that passes through the center 150FC of the pressure-contact-side inclined surface 150F in the radial direction M and is parallel to the axial direction of the output shaft 15 passes through the guide portion 238 when the weight member 230 is positioned on the outer side M1 in the radial direction M. According to the above aspect, the guide portion 238 is relatively large, and therefore the range of movement of the cylindrical member 270 in the radial direction M can be made wider.

[0094] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 with the weight member 230 positioned on the outer side M1 in the radial direction M, the pressure-contact-side inclined surface 150F and at least a portion of the guide portion 238 overlap. According to the above aspect, the guide portion 238 can be arranged compactly in the radial direction M, which makes it possible to prevent the weight member 230 from becoming large in size in the radial direction M.

[0095] In the clutch device 10 of this embodiment, the length L9 of the cylindrical member 270 in the circumferential direction S is equal to or greater than one-fourth the length L8 of the weight-side inclined surface 130F in the circumferential direction S. According to the above aspect, the cylindrical member 270 can roll smoothly relative to the weight member 230 and the holding member 240.

[0096] In the clutch device 10 of this embodiment, the holding member 240 is provided with a holding-member-side guide portion 245 that is formed on a surface 245M facing the weight member 230, that holds the cylindrical member 270 so that a portion 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, and that guides movement of the cylindrical member 270 in the radial direction M. According to the above aspect, the movement of the cylindrical member 270 in the radial direction M can be more reliably guided.

[0097] In the clutch device 10 of this embodiment, when viewed from the axial direction of the output shaft 15 with the weight member 230 positioned on the inner side M2 ​​in the radial direction M, at least a portion of the weight-side inclined surface 130F overlaps with the retaining member-side guide portion 245. According to the above aspect, the movement of the cylindrical member 270 in the radial direction M can be smoothly guided.

[0098] <Third embodiment> As shown in Figure 31, a 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 Figure 1).

[0099] 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 engagement claw 143 and the accommodating recess 345 in the radial direction M. The wall portion 341A defines a part of the accommodating recess 345.

[0100] 31 , the accommodating recess 345 is formed in the main body 341 so as to be recessed in the axial direction of the output shaft 15. The accommodating recess 345 is recessed in a first direction D1. The accommodating recess 345 accommodates the weight member 130 so as to be movable in the radial direction M. An end portion 345X of the accommodating recess 345 on the outer side M1 in the radial direction M abuts one end of each of the first spring 161 and the second spring 162.

[0101] 31 , the length L10 of the wall portion 341A in the radial direction M 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 143X on the outer side M1 in the radial direction M of the engagement 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 345X on the outer side M1 in the radial direction M of the accommodating recess 345. The length L11 in the circumferential direction S of the wall portion 341A is equal to or longer than the length L2 of the engagement claw 143 in the circumferential direction S.

[0102] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0103] In the above-described embodiments, the spring 160 is given as an example of the biasing member, but the biasing member is not limited to this. The biasing member may be, for example, an elastic body such as rubber.

[0104] In the above-described embodiments, the pressure-side inclined surface 150F is an example of the pressure-side sliding portion, and the weight-side inclined surface 130F is an example of the weight-side sliding portion, both of which are inclined surfaces inclined with respect to the axial direction (i.e., direction D) of the output shaft 15. However, the present invention is not limited to this. It is sufficient that at least one of the pressure-side sliding portion and the weight-side sliding portion is 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.

[0105] In the above-described embodiments, the weight members 130, 230 include the biasing member holding portion 131, but may not include the biasing member holding portion 131. In this case, for example, the spring 160 is disposed so as to abut against an end (e.g., an end face) of the weight member 130, 230 on the outer side M1 in the radial direction M.

[0106] In the above-described embodiments, two springs 160 are provided for one weight member 130, but this is not limiting. One spring 160 may be provided for one weight member 130, or three or more springs 160 may be provided for one weight member 130. For example, when one spring 160 is provided for one weight member 130, the weight member 130 may have one biasing member holding portion 131, and two flat surfaces (i.e., a first flat surface 133 and a second flat surface 135) that are slidable relative to the holding member 140 may be provided on each side of the one biasing member holding portion 131 in the circumferential direction S.

[0107] In the first embodiment described above, the weight member 130 includes the first flat surface 133 and the second flat surface 135 that are provided so as to be slidable relative to the holding member 140. However, the weight member 130 may include only one of these flat surfaces. 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 more effectively relative to the holding member 140 via the first flat surface 133 or the second flat surface 135.

[0108] In the first embodiment described above, the weight member 130 includes the first flat surface 133 and the second flat surface 135 that are provided slidably relative to the holding member 140. However, the first flat surface 133 and the second flat surface 135 may not slide relative to the holding member 140, and only the third flat surface 137 may be provided slidably relative to the holding member 140. Furthermore, any one, any two, or all of the first flat surface 133, the second flat surface 135, and the third flat surface 137 may be provided slidably relative to the holding member 140.

[0109] In the first embodiment described above, the first plane 133, the second plane 135, and the third plane 137 were located on the opposite side of the weight-side inclined surface 130F in the axial direction of the output shaft 15 (i.e., direction D), but they may also be located on the same side as the weight-side inclined surface 130F.

[0110] In each of the above-described embodiments, the pressing member 150 is configured to indirectly press the input side rotating plate 20 and the output side rotating plate 22 together via the flange 68 of the second clutch center 51, but this is not limiting. The pressing member 150 may also be configured to press the input side rotating plate 20 and the output side rotating plate 22 together by directly pressing the input side rotating plate 20 or the output side rotating plate 22.

[0111] In each of the above-described embodiments, the pressure member 70 (more specifically, the pressure side fitting tooth 87 ) holds one output side rotating plate 22 , but it may also hold multiple output side rotating plates 22 .

[0112] In the above-described embodiments, the pressure member 70 holds some of the output rotating plates 22, and the clutch center 40 (more specifically, the second clutch center 51) holds other parts of the output rotating plates 22. However, this is not limiting. For example, the pressure member 70 may hold all of the output rotating plates 22, and the clutch center 40 may not hold any of the output rotating plates 22.

[0113] 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 formed integrally.

[0114] In each of the above-described embodiments, the weight member 130 is configured to directly press the pressing member 150, but it may also be configured to indirectly press the pressing member 150.

[0115] In each of the above-described embodiments, an engine is used as the drive source, but the drive source is not limited to an engine and may be, for example, an electric motor.

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

[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 130F Weight side inclined surface (weight side sliding portion) 131 Urging member holding portion 131A First urging member holding portion 131B Second urging member holding portion 132 Holding wall 133 First flat surface 133A Radially inner end portion 135 Second flat surface 135A Radially inner end portion 137 Third flat surface 140 Holding member 145 Accommodating recess 145M Sliding surface 150 Pressing member 150F Pressing side inclined surface (pressing side sliding portion) 160 Spring (pressing member) 161 First spring 162 Second spring 220 Centrifugal clutch mechanism 230 Weight member 238 Guide portion 238S First restricting portion 238M Second restricting portion 238P Accommodation groove 240 Holding member 245 Holding member side guide portion 270 Cylindrical member

Claims

1. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotary plates that are rotationally driven by the rotational drive of the input shaft, and that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or move away from the clutch center, that holds at least some of the plurality of output side rotary plates that are arranged alternately with the input side rotary plate, and that is able to press the input side rotary plate and the output side rotary plate; a centrifugal clutch mechanism having a plurality of weight members configured to be movable from a radially inner position to an outer position by centrifugal force accompanying rotation of the clutch housing, and which presses the input side rotating plate and the output side rotating plate together when the weight members are at the radially outer positions, thereby enabling transmission of the rotational drive force of the input shaft to the output shaft, and which releases the pressing force between the input side rotating plate and the output side rotating plate when the weight members are at the radially inner positions, thereby blocking transmission of the rotational drive force of the input shaft to the output shaft, The centrifugal clutch mechanism includes: a holding member that holds the weight member movably between an inner position in the radial direction and an outer position in the radial direction; a biasing member provided on the holding member and biasing the weight member inward in the radial direction; a pressing member having a pressing-side sliding portion provided so as to be able to come into contact with the weight member, and which moves in the axial direction of the output shaft as the weight member moves from a radially inner position to a radially outer position, thereby pressing the input-side rotating plate and the output-side rotating plate together, The weight member includes: a weight-side sliding portion that is a plane extending in a direction intersecting an axial direction of the output shaft and is slidable relative to the pressure-contact-side sliding portion, At least one of the pressure-contact-side sliding portion and the weight-side sliding portion has an inclined surface inclined with respect to the axial direction of the output shaft, a clutch device in which, when a direction in which the pressing member approaches the weight member is defined as a first direction and a direction in which the pressing member moves away from the weight member is defined as a second direction, a surface of the weight member facing the second direction that is radially inward of the weight-side sliding portion is positioned closer to the first direction than the weight-side sliding portion in a cross-sectional view taken along a plane including the axial direction and the radial direction of the output shaft.

2. The weight member includes: a biasing member holding portion that holds the biasing member; a first plane extending in a direction intersecting an axial direction of the output shaft and slidable relative to the holding member; the first plane is provided on one side in the circumferential direction of the biasing member holding portion, The clutch device according to claim 1, wherein the weight-side sliding portion is located on the opposite side of the first plane in the axial direction of the output shaft.

3. 3. The clutch device according to claim 2, wherein the weight member is provided on the other circumferential side of the biasing member holding portion, and has a second plane that extends in a direction intersecting the axial direction of the output shaft and is slidable relative to the holding member.

4. the biasing member holding portion includes a holding wall that holds an inner end portion of the biasing member in the radial direction, The clutch device according to claim 3 , wherein the radially inner end of the first plane and the radially inner end of the second plane are located radially inward of the retaining wall.

5. outer ends of the first plane and the second plane in the radial direction are located radially outward of an inner end of the weight-side sliding portion in the radial direction, 4. The clutch device according to claim 3, wherein the radially inner ends of the first plane and the second plane are located radially inward of the radially inner end of the weight-side sliding portion.

6. The clutch device according to claim 5, wherein the radial length of the first plane and the second plane is longer than the radial length of the weight-side sliding portion.

7. 4. The clutch device according to claim 3, wherein a total area of ​​the first plane and the second plane is larger than an area of ​​the weight-side sliding portion.

8. 4. The clutch device according to claim 3, wherein the circumferential length from one end of the first plane in the circumferential direction to the other end of the second plane in the circumferential direction is longer than the circumferential length of the weight-side sliding portion.

9. The clutch device according to claim 3 , further comprising a plurality of said biasing members disposed between said first plane and said second plane in said circumferential direction.

10. 4. The clutch device according to claim 3, wherein, in a cross-sectional view on a plane including the axial direction and the radial direction of the output shaft, a straight line passing through the radial center of the pressure-contact-side sliding portion and parallel to the axial direction of the output shaft passes through the first plane and the second plane when the weight member is positioned on the outer side in the radial direction.

11. the pressure-contact-side sliding portion is a pressure-contact-side inclined surface inclined with respect to the axial direction of the output shaft, 4. The clutch device according to claim 3, wherein the weight-side sliding portion is a weight-side inclined surface that is inclined with respect to the axial direction of the output shaft and slides on the pressure-contact-side inclined surface.

12. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotary plates that are rotationally driven by the rotational drive of the input shaft, and that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or move away from the clutch center, that holds at least some of the plurality of output side rotary plates that are arranged alternately with the input side rotary plate, and that is able to press the input side rotary plate and the output side rotary plate; a centrifugal clutch mechanism having a plurality of weight members configured to be movable from a radially inner position to an outer position by centrifugal force accompanying rotation of the clutch housing, and which presses the input side rotating plate and the output side rotating plate together when the weight members are at the radially outer positions, thereby enabling transmission of the rotational drive force of the input shaft to the output shaft, and which releases the pressing force between the input side rotating plate and the output side rotating plate when the weight members are at the radially inner positions, thereby blocking transmission of the rotational drive force of the input shaft to the output shaft, The centrifugal clutch mechanism includes: a holding member that holds the weight member movably between an inner position in the radial direction and an outer position in the radial direction; a pressing member that moves in the axial direction of the output shaft as the weight member moves from the radially inner position to the radially outer position, and presses the input side rotating plate and the output side rotating plate into contact with each other; a cylindrical member that is provided between the weight member and the holding member in the axial direction of the output shaft, that extends in a direction intersecting the radial direction, and that rolls relative to the weight member and the holding member, the weight member is provided with a guide portion that is formed on a surface facing the retaining member, that holds the cylindrical member so that a portion of the cylindrical member protrudes from the surface of the weight member facing the retaining member toward the retaining member, and that guides the radial movement of the cylindrical member.

13. 13. The clutch device according to claim 12, wherein the guide portion includes a first restricting portion that restricts the cylindrical member from moving in the circumferential direction, and a second restricting portion that restricts the cylindrical member from moving in the radial direction by more than a predetermined distance.

14. 14. The clutch device according to claim 13, wherein the guide portion has an accommodation groove that is recessed in a direction from the holding member toward the weight member in the axial direction of the output shaft and that accommodates a portion of the cylindrical member.

15. The clutch device according to claim 14, wherein the first restricting portion and the second restricting portion define the accommodation groove.

16. the centrifugal clutch mechanism includes a biasing member provided on the holding member and biasing the weight member inward in the radial direction, 13. The clutch device according to claim 12, wherein, in a cross-sectional view taken along a plane including the axial direction and the radial direction of the output shaft, when the weight member is positioned radially inward, at least a portion of the cylindrical member overlaps with the biasing member.

17. the biasing member includes a first biasing member and a second biasing member arranged in a circumferential direction, 17. The clutch device according to claim 16, wherein the cylindrical member is located between the first biasing member and the second biasing member in the circumferential direction.

18. the centrifugal clutch mechanism includes a biasing member provided on the holding member and biasing the weight member inward in the radial direction, 13. The clutch device according to claim 12, wherein, in a cross-sectional view taken along a plane including the axial direction and the radial direction of the output shaft, when the weight member is positioned radially inward, at least a portion of the guide portion overlaps with the biasing member.

19. the pressing member has a pressing-side sliding portion provided so as to be able to come into contact with the weight member, the weight member has a weight-side sliding portion that is slidable relative to the pressure-contact-side sliding portion, At least one of the pressure-contact-side sliding portion and the weight-side sliding portion has an inclined surface inclined with respect to the axial direction of the output shaft, 13. The clutch device according to claim 12, wherein, in a cross-sectional view on a plane including the axial direction and the radial direction of the output shaft, a straight line passing through the radial center of the pressure-contact-side sliding portion and parallel to the axial direction of the output shaft passes through the guide portion when the weight member is positioned on the radial outside.

20. the pressing member has a pressing-side sliding portion provided so as to be able to come into contact with the weight member, the weight member has a weight-side sliding portion that is slidable relative to the pressure-contact-side sliding portion, At least one of the pressure-contact-side sliding portion and the weight-side sliding portion has an inclined surface inclined with respect to the axial direction of the output shaft, 13. The clutch device according to claim 12, wherein when viewed in the axial direction of the output shaft with the weight member positioned radially outward, the pressure-contact side sliding portion and at least a portion of the guide portion overlap.

21. the pressing member has a pressing-side sliding portion provided so as to be able to come into contact with the weight member, the weight member has a weight-side sliding portion that is slidable relative to the pressure-contact-side sliding portion, At least one of the pressure-contact-side sliding portion and the weight-side sliding portion has an inclined surface inclined with respect to the axial direction of the output shaft, 13. The clutch device according to claim 12, wherein the circumferential length of the cylindrical member is equal to or greater than one-fourth of the circumferential length of the weight-side sliding portion.

22. 13. The clutch device according to claim 12, wherein the retaining member includes a retaining member-side guide portion formed on a surface facing the weight member, the retaining member holding the cylindrical member so that a portion of the cylindrical member protrudes from the surface of the retaining member facing the weight member toward the weight member, and the retaining member-side guide portion guides the radial movement of the cylindrical member.

23. the pressing member has a pressing-side sliding portion provided so as to be able to come into contact with the weight member, the weight member has a weight-side sliding portion that is slidable relative to the pressure-contact-side sliding portion, At least one of the pressure-contact-side sliding portion and the weight-side sliding portion has an inclined surface inclined with respect to the axial direction of the output shaft, 23. The clutch device according to claim 22, wherein when viewed from the axial direction of the output shaft with the weight member positioned radially inward, at least a portion of the weight-side sliding portion and the holding member-side guide portion overlap.

24. A clutch device as described in claim 1, wherein the radial length of the weight side sliding portion is shorter than the radial length of the radial inner surface.

25. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotary plates that are rotationally driven by the rotational drive of the input shaft, and that is rotationally driven together with the output shaft; a pressure member that is provided so as to be able to approach or move away from the clutch center, that holds at least some of the plurality of output side rotary plates that are arranged alternately with the input side rotary plate, and that is able to press the input side rotary plate and the output side rotary plate; a centrifugal clutch mechanism having a plurality of weight members configured to be movable from a radially inner position to an outer position by centrifugal force accompanying rotation of the clutch housing, and which presses the input side rotating plate and the output side rotating plate together when the weight members are at the radially outer positions, thereby enabling transmission of the rotational drive force of the input shaft to the output shaft, and which releases the pressing force between the input side rotating plate and the output side rotating plate when the weight members are at the radially inner positions, thereby blocking transmission of the rotational drive force of the input shaft to the output shaft, The centrifugal clutch mechanism includes: a holding member that holds the weight member movably between an inner position in the radial direction and an outer position in the radial direction; a biasing member provided on the holding member and biasing the weight member inward in the radial direction; a pressing member having a pressing-side sliding portion provided so as to be able to come into contact with the weight member, and which moves in the axial direction of the output shaft as the weight member moves from a radially inner position to a radially outer position, thereby pressing the input-side rotating plate and the output-side rotating plate together, The weight member includes: a weight-side sliding portion that is a plane extending in a direction intersecting an axial direction of the output shaft and is slidable relative to the pressure-contact-side sliding portion, the biasing members include a first biasing member and a second biasing member arranged in a circumferential direction with respect to one of the weight members, a first circumferential direction is a direction from one side to the other side in the circumferential direction, and a second circumferential direction is a direction from the other side to the one side, the clutch center and the pressure member are configured to rotate in the first circumferential direction, the first biasing member is located on the second circumferential direction side of the second biasing member, when viewed from the axial direction of the output shaft, the weight-side sliding portion extends continuously from a portion on the second circumferential side of the first biasing member to a portion on the first circumferential side of the second biasing member.