Clutch device

Abstract

A clutch device 10 comprises: a clutch center 40; a pressure plate 70; a centrifugal clutch mechanism 120 having a plurality of weight members 122; and a clutch spring 25 that presses the pressure plate 70 in association with actuation of the centrifugal clutch mechanism 120. The clutch spring 25 is configured to press the pressure plate 70 in a first direction D1 as a result of the weight members 122 moving from a radially inner position PI1 to a radially outer position PO1, thus bringing a drive-side clutch plate 20 and a driven-side clutch plate 22 into pressure contact with each other. An end 25D1 of the clutch spring 25 in the first direction D1 is located on a surface side of the pressure plate 70 in a second direction D2, farther on the second direction D2 side than an end 77D1 of a mating tooth 77 of the pressure plate 70 in the first direction D1, and farther on the first direction D1 side than a center 77C of the mating tooth 77 in the direction D.

Description

Clutch device

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

[0002] A saddle-type vehicle such as a motorcycle includes a clutch device that can transmit and cut off 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 having an input member connected to the engine side, an output member connected to the driving wheel side, a clutch member (hereinafter referred to as a clutch center) connected to the output member, and a pressure member (hereinafter referred to as a pressure plate) that can approach or separate from the clutch center. Patent Document 1 also discloses a centrifugal clutch means in which a weight member moves from a first position to a second position due to centrifugal force associated with the rotation of a clutch housing, and a driving-side clutch plate and a driven-side clutch plate are pressed against each other.

[0003] Japanese Unexamined Patent Application Publication No. 2022-030211

[0004] By the way, in Patent Document 1, the clutch center holds some of the driven-side clutch plates, and the pressure plate holds some of the other driven-side clutch plates. However, in the case of a configuration where the pressure plate holds all the driven-side clutch plates, there is a possibility that the driving-side clutch plate and the driven-side clutch plate cannot be sufficiently pressed against each other even when the weight member moves from the first position to the second position.

[0005] The present invention has been made in view of such a point, and an object thereof is to provide a clutch device capable of sufficiently pressing a driving-side clutch plate and a driven-side clutch plate against each other.

[0006] The clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input member to an output member, and is housed in a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by the rotational drive of the input member, and a clutch center that is rotationally driven together with the output member, and a pressure plate that is provided so as to be able to approach or move away from the clutch center and so as to be rotatable relative to it, and holds all of the plurality of driven-side clutch plates that are arranged alternately with the drive-side clutch plates, and is capable of pressing the drive-side clutch plates and the driven-side clutch plates. The clutch mechanism includes a centrifugal clutch mechanism having a plurality of weight members that can move from a first position in which the pressing force between the drive-side clutch plate and the driven-side clutch plate is released as the centrifugal force increases due to the rotation of the clutch housing, thereby blocking the transmission of the rotational driving force of the input member to the output member, to a second position in which the drive-side clutch plate and the driven-side clutch plate are pressed together, making it possible to transmit the rotational driving force of the input member to the output member; and a pressing member that presses the pressure plate in conjunction with the operation of the centrifugal clutch mechanism. When the direction in which the reducing plate approaches the clutch center is defined as the first direction, and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the pressure plate comprises a base wall, an outer peripheral wall extending from the base wall in the first direction and formed in an annular shape when viewed from the axial direction of the output member, a plurality of fitting teeth arranged in the circumferential direction that hold all of the driven clutch plates and protrude radially outward from the outer peripheral surface of the outer peripheral wall, a plurality of spline grooves formed between adjacent fitting teeth, and the second direction The device comprises a recess formed to be recessed in the first direction and accommodating the pressing member, wherein the pressing member is configured to press the pressure plate in the first direction by the weight member moving from the first position to the second position, thereby bringing the drive-side clutch plate and the driven-side clutch plate into contact, and the end of the pressing member in the first direction is located on the second-direction side of the pressure plate and the end of the fitting teeth in the first direction, and on the first direction side of the axial center of the fitting teeth.

[0007] According to the clutch device of the present invention, the end of the pressing member in the first direction that presses the pressure plate in conjunction with the operation of the centrifugal clutch mechanism is located on the second direction side of the pressure plate, on the second direction side of the end of the mating teeth in the first direction, and on the first direction side of the axial center of the mating teeth. According to the above embodiment, the pressing force from the pressure plate pressed by the pressing member is efficiently transmitted by the drive-side clutch plate and the driven-side clutch plate. This makes it possible to sufficiently press the drive-side clutch plate and the driven-side clutch plate together.

[0008] Another clutch device according to the present invention is a clutch device for transmitting or interrupting the rotational driving force of an input member to an output member, comprising: a clutch center housed in a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by the rotational drive of the input member, and which rotates together with the output member; a pressure plate that is movable toward or toward the clutch center and rotatable relative to it, and which holds all of a plurality of driven-side clutch plates that are alternately arranged with the drive-side clutch plates, and which can press the drive-side clutch plates and the driven-side clutch plates; a centrifugal clutch mechanism having a plurality of weight members that are movable from a first position in which the contact force between the drive-side clutch plates and the driven-side clutch plates is released as the centrifugal force increases due to the rotation of the clutch housing, thereby interrupting the transmission of the rotational driving force of the input member to the output member, to a second position in which the drive-side clutch plates and the driven-side clutch plates are pressed together, thereby enabling the transmission of the rotational driving force of the input member to the output member; and in the axial direction of the output member The clutch comprises a pressure contact member positioned between the drive-side clutch plate, the driven-side clutch plate, and the clutch housing. When the direction in which the pressure plate approaches the clutch center is defined as the first direction, and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the pressure contact member is configured to move axially toward the first direction as the weight member moves from the first position to the second position, thereby bringing the drive-side clutch plate and the driven-side clutch plate into contact. The pressure plate comprises an outer peripheral wall extending in the axial direction of the output member and formed in an annular shape when viewed from the axial direction of the output member, a plurality of fitting teeth arranged in the circumferential direction that hold all of the driven clutch plates and protrude radially outward from the outer peripheral surface of the outer peripheral wall, and a plurality of spline grooves formed between adjacent fitting teeth, wherein the pressure contact member is located radially outward from the fitting teeth and has a pressing surface capable of pressing the drive clutch plate or the driven clutch plate.

[0009] In another clutch device according to the present invention, the contact member is located radially outward from the mating teeth and has a pressing surface capable of pressing against the drive-side clutch plate or the driven-side clutch plate. According to the above embodiment, the pressing force from the pressing surface of the contact member, which moves axially due to the movement of the weight member, is efficiently transmitted to the drive-side clutch plate and the driven-side clutch plate. This allows the drive-side clutch plate and the driven-side clutch plate to be sufficiently pressed together.

[0010] According to the present invention, it is possible to provide a clutch device that can sufficiently press the drive-side clutch plate and the driven-side clutch plate into contact.

[0011] Figure 1 is a cross-sectional view showing a part of the clutch device according to the first embodiment. Figure 2 is an exploded perspective view of the clutch center and pressure plate according to the first embodiment. Figure 3 is a perspective view of the pressure plate according to the first embodiment. Figure 4 is a cross-sectional view showing a part of the clutch device according to the first embodiment. Figure 5A is a schematic diagram illustrating the operation of the center-side assist cam surface and the pressure-side assist cam surface. Figure 5B is a schematic diagram illustrating the operation of the center-side slipper cam surface and the pressure-side slipper cam surface. Figure 6 is a cross-sectional view showing a part of the clutch device according to the first modified example. Figure 7 is a cross-sectional view showing a part of the clutch device according to the second modified example. Figure 8 is a cross-sectional view showing a part of the clutch device according to the second embodiment. Figure 9 is a perspective view of the centrifugal clutch mechanism according to the second embodiment. Figure 10 is a cross-sectional view showing a part of the clutch device according to the second embodiment.

[0012] Hereinafter, embodiments of the clutch device according to the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for members and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0013] <First Embodiment> Figure 1 is a cross-sectional view showing a part of the clutch device 10 according to the first embodiment. The clutch device 10 is installed in a vehicle such as a motorcycle. The clutch device 10 is a device that transmits or interrupts the rotational driving force of an input member (crankshaft) of a drive source (e.g., engine) of a motorcycle to an output shaft 15. The clutch device 10 is a device for transmitting or interrupting the rotational driving force of the input member to a drive wheel (rear wheel) via the output shaft 15. The clutch device 10 is arranged between the drive source and the transmission. The output shaft 15 is an example of an output member.

[0014] In the following description, the direction in which the pressure plate 70 of the clutch device 10 approaches and moves away from the clutch center 40 is denoted as direction D, the direction in which the pressure plate 70 approaches the clutch center 40 is denoted as the first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is denoted as the second direction D2. Furthermore, the circumferential direction of the clutch center 40 and the pressure plate 70 is denoted as the circumferential direction S, the direction from one pressure-side cam portion 90 toward the other pressure-side cam portion 90 (the direction from one center-side cam portion 60 toward the other center-side cam portion 60) is denoted as the first circumferential direction S1 (see Figure 3), and the direction from the other pressure-side cam portion 90 toward the one pressure-side cam portion 90 (the direction from the other center-side cam portion 60 toward the one center-side cam portion 60) is denoted as the second circumferential direction S2 (see Figure 3). In this embodiment, the axial direction of the output shaft 15, the axial direction of the clutch housing 30, the axial direction of the clutch center 40, and the axial direction of the pressure plate 70 are the same as direction D. Furthermore, the pressure plate 70 and the clutch center 40 rotate in the first circumferential direction S1 (i.e., the direction from the center-side assist cam surface 60A of one center-side cam portion 60 toward the center-side slipper cam surface 60S). However, the above direction is merely defined for the convenience of explanation and does not limit the installation configuration of the clutch device 10 in any way, nor does it limit the present invention in any way.

[0015] As shown in Figure 1, the clutch device 10 includes an output shaft 15, a drive-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 40, a pressure plate 70, and a centrifugal clutch mechanism 120.

[0016] As shown in Figure 1, the output shaft 15 is a hollow shaft. One end of the output shaft 15 rotatably supports the input gear 35 and clutch housing 30, which will be described later, via a needle bearing 15A. The output shaft 15 fixedly supports the clutch center 40 via a nut 15B. That is, the output shaft 15 rotates integrally with the clutch center 40. The other end of the output shaft 15 is connected to, for example, a transmission (not shown) of a motor vehicle or motorcycle.

[0017] As shown in Figure 1, the output shaft 15 includes a push rod 16A and a push member 16B provided adjacent to the push rod 16A in its hollow portion 15H. The hollow portion 15H functions as a passage for clutch oil. The clutch oil flows inside the output shaft 15, i.e., inside the hollow portion 15H. The push rod 16A and the push member 16B are slidably mounted inside the hollow portion 15H of the output shaft 15. One end of the push rod 16A (the left end in the figure) is connected to the clutch operating lever (not shown) of a motorcycle, and operation of the clutch operating lever causes it to slide inside the hollow portion 15H and press the push member 16B in the second direction D2. The push rod 16A may also be configured to slide inside the hollow portion 15H by a servo motor. 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 plate 70. The push rod 16A and the push member 16B are formed to be thinner than the inner diameter of the hollow portion 15H, ensuring the flow of clutch oil within the hollow portion 15H.

[0018] The clutch housing 30 is made of an aluminum alloy. The clutch housing 30 is formed in a bottomed cylindrical shape. As shown in Figure 1, the clutch housing 30 has a substantially circular bottom wall 31 and side walls 33 extending in direction D from the edge of the bottom wall 31. The clutch housing 30 holds a plurality of drive-side clutch plates 20.

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

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

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

[0022] As shown in Figure 1, the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is positioned concentrically with the clutch housing 30. The clutch center 40 has a cylindrical body 42 and a center-side flange 68 extending radially outward from the outer peripheral edge of the body 42. The body 42 has a portion that protrudes in a second direction D2 from the center-side flange 68. The clutch center 40 does not hold the driven clutch plate 22. The clutch center 40 is rotationally driven together with the output shaft 15.

[0023] As shown in Figure 2, the main body 42 comprises an output shaft holding portion 50, a plurality of center-side cam portions 60, and a center-side fitting portion 58. The center-side cam portions 60 are formed to protrude in a second direction D2 from the center-side flange 68. The center-side cam portions 60 are located radially outward from the output shaft holding portion 50.

[0024] As shown in Figure 2, the center flange 68 extends radially outward from the outer peripheral edge of the main body 42. The center flange 68 is located radially outward from the center cam portion 60. The center flange 68, together with the pressure flange 98 of the pressure plate 70 (described later), clamps the drive clutch plate 20 and the driven clutch plate 22. The center flange 68 is provided so as to be able to press the drive clutch plate 20 and the driven clutch plate 22. The center flange 68 is a member that applies pressing force to the drive clutch plate 20 and the driven clutch plate 22.

[0025] As shown in Figure 2, the output shaft holder 50 is formed in a cylindrical shape. The output shaft holder 50 has an insertion hole 51 into which the output shaft 15 (see Figure 1) is inserted and spline fitted. The insertion hole 51 is formed through the main body 42. Multiple spline grooves are formed along the axial direction on the inner circumferential surface 50A of the output shaft holder 50 that forms the insertion hole 51. The output shaft 15 is connected to the output shaft holder 50.

[0026] The center-side cam portion 60 is formed in a trapezoidal shape and has a cam surface consisting of an inclined surface that constitutes an assist & slipper (registered trademark) mechanism that generates assist torque, which is a force that increases the pressing force (contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22, or slipper torque, which is a force that causes the drive-side clutch plate 20 and the driven-side clutch plate 22 to separate early and transition to a half-clutch state. The half-clutch state is a state between the state in which the clutch is engaged and the state in which the clutch is disengaged. The center-side cam portion 60 is formed on the main body 42. The center-side cam portions 60 are arranged at equal intervals in the circumferential direction S of the clutch center 40. In this embodiment, the clutch center 40 has three center-side cam portions 60, but the number of center-side cam portions 60 is not limited to three.

[0027] As shown in Figure 2, the center-side cam portion 60 is located radially outward from the output shaft holding portion 50. The center-side cam portion 60 has a center-side assist cam surface 60A and a center-side slipper cam surface 60S. The center-side assist cam surface 60A is configured to generate a force (here, a first direction D1) in the direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force (contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the clutch center 40 rotates relative to the pressure plate 70, such as when accelerating. In this embodiment, when the above force is generated, the position of the pressure plate 70 relative to the clutch center 40 does not change, and it is not necessary for the pressure plate 70 to physically approach the clutch center 40. However, the pressure plate 70 may be physically displaced relative to the clutch center 40. The center slipper cam surface 60S is configured to separate the pressure plate 70 from the clutch center 40 in order to reduce the pressing force (contact force) between the drive clutch plate 20 and the driven clutch plate 22 when the clutch center 40 rotates relative to the pressure plate 70, such as when decelerating. In adjacent center cam portions 60 with respect to the circumferential direction S, the center assist cam surface 60A of one center cam portion 60L and the center slipper cam surface 60S of the other center cam portion 60M are arranged facing each other in the circumferential direction S.

[0028] As shown in Figure 2, the clutch center 40 is provided with a plurality of (three in this embodiment) boss portions 54. The boss portions 54 are members that support the pressure plate 70. The plurality of boss portions 54 are arranged at equal intervals in the circumferential direction S. The boss portions 54 are formed in a cylindrical shape. The boss portions 54 are located radially outward from the output shaft holding portion 50. The boss portions 54 extend toward the pressure plate 70 (i.e., toward the second direction D2). The boss portions 54 are provided on the main body 42. The boss portions 54 have screw holes 54H into which bolts (not shown) are inserted. The screw holes 54H extend in the axial direction of the clutch center 40.

[0029] As shown in Figure 2, the clutch center 40 has a center-side cam hole 43H that penetrates the main body 42 and a portion of the center-side flange 68. The center-side cam hole 43H penetrates the main body 42 and the center-side flange 68 in direction D. The center-side cam hole 43H extends from the side of the output shaft holding portion 50 to the center-side flange 68. The center-side cam hole 43H is formed between the center-side assist cam surface 60A and the boss portion 54 of the center-side cam portion 60. When viewed from the axial direction of the clutch center 40, the center-side assist cam surface 60A and a portion of the center-side cam hole 43H overlap.

[0030] As shown in Figure 2, the center-side fitting portion 58 is provided on the main body 42. The center-side fitting portion 58 is located radially outward from the center-side cam portion 60. The center-side fitting portion 58 is located on the first direction D1 side of the center-side cam portion 60. The center-side fitting portion 58 is configured to be slidably fitted into the pressure-side fitting portion 88 (see Figure 3).

[0031] As shown in Figure 1, the pressure plate 70 is housed in the clutch housing 30. The pressure plate 70 is located on the second direction D2 side of the clutch center 40. The pressure plate 70 is provided so as to be able to move toward or away from the clutch center 40 and to be able to rotate relative to it. The pressure plate 70 is configured to be able to press against the drive-side clutch plate 20 and the driven-side clutch plate 22. The pressure plate 70 is arranged concentrically with the clutch center 40 and the clutch housing 30. As shown in Figures 2 and 3, the pressure plate 70 has a cylindrical body 72 and a pressure-side flange 98 extending radially outward from the outer peripheral edge of the body 72. The body 72 has a portion that protrudes in the first direction D1 from the pressure-side flange 98. The pressure plate 70 holds all of the drive-side clutch plate 20 and the plurality of driven-side clutch plates 22 that are arranged alternately in direction D.

[0032] The driven clutch plate 22 is held in a spline fitting portion 76 of the pressure plate 70, which will be described later. The driven clutch plate 22 is held in the fitting teeth 77 (see Figures 2 and 3) and spline grooves 78 (see Figures 2 and 3) of the pressure plate 70 by spline fitting, which will be described later. The driven clutch plate 22 is provided so as to be displaceable along the axial direction (i.e., direction D) of the pressure plate 70. The driven clutch plate 22 is provided so as to be rotatable integrally with the pressure plate 70.

[0033] The driven clutch plate 22 is a component that is pressed against the drive clutch plate 20. The driven clutch plate 22 is formed in an annular shape. The driven clutch plate 22 is formed by punching out an annular shape from a thin sheet material made of SPCC material. The friction material provided on the drive clutch plate 20 may be provided on the driven clutch plate 22 instead of the drive clutch plate 20, or it may be provided on both the drive clutch plate 20 and the driven clutch plate 22.

[0034] As shown in Figures 2 and 3, the main body 72 includes an annular base wall 73, an outer peripheral wall 75 extending from the base wall 73 toward a first direction D1, a cylindrical portion 80 provided in the center of the base wall 73, a plurality of pressure-side cam portions 90 connected to the base wall 73 and the outer peripheral wall 75, a pressure-side fitting portion 88, a spring housing portion 89, and a boss portion housing hole 84.

[0035] As shown in Figures 2 and 3, the pressure-side flange 98 extends radially outward from the outer peripheral edge of the base wall 73 of the main body 72. The pressure-side flange 98 is located radially outward from the pressure-side cam portion 90. The pressure-side flange 98, together with the center-side flange 68 of the clutch center 40, clamps the drive-side clutch plate 20 and the driven-side clutch plate 22. The pressure-side flange 98 is provided so as to be able to press against the drive-side clutch plate 20 and the driven-side clutch plate 22. The pressure-side flange 98 is a member that applies pressing force to the drive-side clutch plate 20 and the driven-side clutch plate 22. The pressure-side flange 98 has a first flange surface 98D1 located in the first direction D1 and a second flange surface 98D2 located in the second direction D2. The first flange surface 98D1 is provided so as to be able to contact the drive-side clutch plate 20 or the driven-side clutch plate 22. The first flange surface 98D1 is configured to be able to press (press against) the drive-side clutch plate 20 and the driven-side clutch plate 22. The pressure-side flange 98 is an example of a flange.

[0036] The cylindrical portion 80 is formed in a cylindrical shape. The cylindrical portion 80 is formed integrally with the pressure-side cam portion 90. The cylindrical portion 80 houses the tip portion 15T (see Figure 1) of the output shaft 15. The release bearing 18 (see Figure 1) is housed in the cylindrical portion 80. The cylindrical portion 80 is the part that receives the pressing force from the push member 16B. The cylindrical portion 80 is the part that receives the clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0037] As shown in Figure 3, the outer peripheral wall 75 is positioned radially outward from the cylindrical portion 80. The outer peripheral wall 75 is formed in an annular shape when viewed from the axial direction of the output shaft 15. The outer peripheral wall 75 extends in the axial direction (i.e., direction D) of the output shaft 15. A spline fitting portion 76 is provided on the outer peripheral surface 75A of the outer peripheral wall 75. The spline fitting portion 76 has a plurality of fitting teeth 77 that extend along the outer peripheral surface 75A of the outer peripheral wall 75 in the axial direction (i.e., direction D) of the pressure plate 70, and a plurality of spline grooves 78 formed between adjacent fitting teeth 77 and extending in the axial direction of the pressure plate 70. The fitting teeth 77 hold all of the driven clutch plates 22. The plurality of fitting teeth 77 are arranged in the circumferential direction S. The plurality of fitting teeth 77 are formed at equal intervals in the circumferential direction S. The plurality of fitting teeth 77 are formed in the same shape. The mating teeth 77 protrude radially outward from the outer peripheral surface 75A of the outer peripheral wall 75. The multiple spline grooves 78 are aligned in the circumferential direction S. As shown in Figure 1, when the weight member 122 is in the radially inward position PI1, the end 77D1 of the mating teeth 77 in the first direction D1 is located on the second direction D1 side of the second direction D2 side surface 20LD2 of the drive-side clutch plate 20L that is located furthest to the first direction D1 side among the multiple drive-side clutch plates 20.

[0038] The pressure-side cam portion 90 is formed in a trapezoidal shape and has a cam surface consisting of an inclined surface that slides against the center-side cam portion 60 to generate assist torque or slipper torque, forming an assist & slipper (registered trademark) mechanism. As shown in Figure 3, the pressure-side cam portion 90 is formed to protrude from the pressure-side flange 98 in a first direction D1. The pressure-side cam portion 90 is formed to protrude from the base wall 73 in a first direction D1. The pressure-side cam portions 90 are arranged at equal intervals in the circumferential direction S of the pressure plate 70. In this embodiment, the pressure plate 70 has three pressure-side cam portions 90, but the number of pressure-side cam portions 90 is not limited to three.

[0039] As shown in Figure 3, the pressure-side cam portion 90 is located radially outward of the cylindrical portion 80. The pressure-side cam portion 90 is located radially inward of the outer peripheral wall 75. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also Figure 2) and a pressure-side slipper cam surface 90S. The pressure-side assist cam surface 90A is configured to be in contact with the center-side assist cam surface 60A. The pressure-side assist cam surface 90A is configured to generate a force in the direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force (contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 70 rotates relative to the clutch center 40, such as when accelerating. The pressure-side slipper cam surface 90S is configured to be in contact with the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to separate the pressure plate 70 from the clutch center 40 in order to reduce the pressing force (contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 70 rotates relative to the clutch center 40, such as when decelerating. In adjacent pressure-side cam portions 90 with respect to 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 facing each other in the circumferential direction S.

[0040] Here, the operation of the center-side cam portion 60 and the pressure-side cam portion 90 will be explained. When the engine speed increases and the rotational driving force input to the input gear 35 and clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, a first rotational force in the circumferential direction S1 is applied to the pressure plate 70, as shown in Figure 5A. As a result, a force in the first direction D1 is generated on the pressure plate 70 due to the action of the center-side assist cam surface 60A and the pressure-side assist cam surface 90A. This increases the contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22.

[0041] On the other hand, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30, resulting in back torque, a first rotational force in the circumferential direction S1 is applied to the clutch center 40, as shown in Figure 5B. As a result, the action of the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S moves the pressure plate 70 in the second direction D2, releasing the contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22. This makes it possible to avoid malfunctions in the engine and transmission caused by back torque.

[0042] As shown in Figure 3, the pressure-side fitting portion 88 is located radially outward from the cylindrical portion 80. The pressure-side fitting portion 88 is located radially outward from the pressure-side cam portion 90. The pressure-side fitting portion 88 is located on the first direction D1 side of the pressure-side cam portion 90. The pressure-side fitting portion 88 is formed on the inner circumferential surface 75B of the outer circumferential wall 75. The pressure-side fitting portion 88 is configured to slidably fit onto the center-side fitting portion 58 (see Figure 2). A gap is formed between the pressure-side fitting portion 88 and the center-side fitting portion 58.

[0043] As shown in Figures 2 and 3, the pressure plate 70 has a pressure-side cam hole 73H that penetrates a portion of the base wall 73. The pressure-side cam hole 73H penetrates the base wall 73 in direction D. The pressure-side cam hole 73H is located radially outward from the cylindrical portion 80. The pressure-side cam hole 73H extends from the side of the cylindrical portion 80 to the outer peripheral wall 75. The pressure-side cam hole 73H is formed through between adjacent pressure-side cam portions 90. The pressure-side cam hole 73H is formed through between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 90. When viewed from the axial direction of the pressure plate 70, the pressure-side assist cam surface 90A and a portion of the pressure-side cam hole 73H overlap. Clutch oil flows into the pressure-side cam hole 73H from outside the pressure plate 270.

[0044] As shown in FIGS. 2 and 3, the boss portion accommodation hole 84 is formed in the pressure side cam portion 90. The boss portion accommodation hole 84 is a through hole that penetrates the pressure side cam portion 90. The boss portion 54 (see FIG. 2) is inserted into the boss portion accommodation hole 84. The boss portion accommodation hole 84 is formed in a circular shape. The boss portion accommodation hole 84 is positioned between the pressure side cam hole 73H and the spring accommodation portion 89 in the circumferential direction S.

[0045] As shown in FIG. 2, the spring accommodation portion 89 is formed in the pressure side cam portion 90. The spring accommodation portion 89 is formed so as to be recessed from the second direction D2 to the first direction D1. The spring accommodation portion 89 is formed in a circular shape. As shown in FIG. 1, the spring accommodation portion 89 accommodates the clutch spring 25.

[0046] As shown in Figure 1, the clutch spring 25 is located between the pressure plate 70 and the centrifugal clutch mechanism 120. The clutch spring 25 is housed in a spring housing 89. The end 25D1 of the clutch spring 25 in the first direction D1 is located on the side of the pressure plate 70 in the second direction D2. The end 25D1 of the clutch spring 25 in the first direction D1 is located on the second direction D2 side of the end 77D1 of the mating teeth 77 in the first direction D1. The end 25D1 of the clutch spring 25 in the first direction D1 is located on the first direction D1 side of the pressure-side flange 98. The end 25D1 of the clutch spring 25 in the first direction D1 is located on the first direction D1 side of the axial (i.e., direction D) center 77C of the output shaft 15 of the mating teeth 77. The clutch spring 25 biases the pressure plate 70 toward the clutch center 40 (i.e., toward the first direction D1). The clutch spring 25 is, for example, a coil spring made by winding spring steel in a spiral shape. The clutch spring 25 presses the pressure plate 70 in conjunction with the operation of the centrifugal clutch mechanism 120 (as the weight member 122, described later, moves). The clutch spring 25 is configured to press the pressure plate 70 in a first direction D1 as the weight member 122 moves from a radially inward position PI1 (see Figure 1) to a radially outward position PO1 (see Figure 4), causing the drive-side clutch plate 20 and the driven-side clutch plate 22 to come into contact. The clutch spring 25 is an example of a pressing member. The radially inward position PI1 is an example of a first position. The radially outward position PO1 is an example of a second position. Figure 1 is a cross-sectional view of the clutch device 10 showing the state in which the weight member 122 is located at the radially inward position PI1. Figure 4 is a cross-sectional view of the clutch device 10 showing the state in which the weight member 122 is located at position PO1 on the radially outer side.

[0047] As shown in FIG. 1, the centrifugal clutch mechanism 120 is provided at an end portion 30D2 on the opening side (second direction D2 side) of the clutch housing 30. The centrifugal clutch mechanism 120 is provided so as to be rotatable integrally with the clutch housing 30. The centrifugal clutch mechanism 120 is provided on the second direction D2 side of the pressure plate 70. The centrifugal clutch mechanism 120 includes a plurality of weight members 122, a holding member 124 that houses the weight members 122, and an interlocking member 130. The centrifugal clutch mechanism 120 can block the transmission of the rotational driving force of the input member to the output shaft 15 by releasing the pressing force between the driving clutch plate 20 and the driven clutch plate 22 when the weight member 122 is at the radially inner position PI1 (see FIG. 1). The centrifugal clutch mechanism 120 can bring the driving clutch plate 20 and the driven clutch plate 22 into pressure contact to transmit the rotational driving force of the input member to the output shaft 15 when the weight member 122 is at the radially outer position PO1 (see FIG. 4). [[ID=!]]

[0048] The weight member 122 is movable from a first position PI1 (see FIG. 1) where it can block the transmission of the rotational driving force of the input member to the output shaft 15 by releasing the pressing force between the driving clutch plate 20 and the driven clutch plate 22 as the centrifugal force increases with the rotation of the clutch housing 30, to a second position PO1 (see FIG. 4) where it can bring the driving clutch plate 20 and the driven clutch plate 22 into pressure contact to transmit the rotational driving force of the input member to the output shaft 15. The weight member 122 is formed in a spherical shape. The weight member 122 is, for example, a steel ball. The weight member 122 is held at the radially inner position PI1 by a spring (not shown) in a state where no centrifugal force is applied. The weight member 122 moves radially outward against the biasing force of the spring (not shown) when centrifugal force is applied, and moves to the radially outer position PO1.

[0049] As shown in Figure 1, the retaining member 124 holds the weight member 122 so that it can move between a radially inward position PI1 and a radially outward position PO1. The retaining member 124 is provided with a contact surface 124A against which the weight member 122 abuts when the weight member 122 moves radially. The contact surface 124A is inclined toward the first direction D1 as it moves from the radially inward to the radially outward. The retaining member 124 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30.

[0050] As shown in Figure 1, the interlocking member 130 is attached to the holding member 124. The interlocking member 130 is provided so as to be displaceable along the axial direction (i.e., direction D) of the clutch housing 30. The interlocking member 130 and the holding member 124 are provided so as to be rotatable integrally with the clutch housing 30. The interlocking member 130 holds the clutch spring 25 housed in the spring housing 89. The interlocking member 130 contacts the end 25D2 of the clutch spring 25 in the second direction D2. The interlocking member 130, together with the holding member 124, holds the weight member 122. The interlocking member 130 is configured to move in the first direction D1 as the weight member 122 moves from a radially inward position PI1 to a radially outward position PO1, thereby pressing the clutch spring 25 in the first direction D1.

[0051] In the centrifugal clutch mechanism 120 with the above configuration, when no centrifugal force is applied to the weight member 122, the weight member 122 is held at a radially inward position PI1 (see Figure 1), and the contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22 is released. On the other hand, when centrifugal force is applied to the weight member 122, the weight member 122 moves from the radially inward position PI1 to the radially outward position PO1 (see Figure 4). As a result, the interlocking member 130 is pressed by the weight member 122 and moves in the first direction D1. When the pressing force from the weight member 122 to the interlocking member 130 can no longer be absorbed by the clutch spring 25, the pressing force is transmitted to the pressure plate 70 via the clutch spring 25, and the pressure plate 70 moves in the first direction D1. As a result, the drive-side clutch plate 20 and the driven-side clutch plate 22 are pressed against each other by the pressure-side flange 98 and the center-side flange 68, creating a press-fit state, which allows the rotational driving force of the input member to be transmitted to the output shaft 15.

[0052] As described above, according to the clutch device 10 of this embodiment, the end 25D1 of the clutch spring 25 that presses the pressure plate 70 in conjunction with the operation of the centrifugal clutch mechanism 120 is located on the side of the pressure plate 70 in the second direction D2, and is further to the second direction D2 than the end 77D1 of the fitting teeth 77 in the first direction D1, and is further to the first direction D1 than the axial center 77C of the fitting teeth 77. According to the above embodiment, the pressing force from the pressure plate 70 pressed by the clutch spring 25 is efficiently transmitted by the drive-side clutch plate 20 and the driven-side clutch plate 22. As a result, the drive-side clutch plate 20 and the driven-side clutch plate 22 can be sufficiently pressed into contact.

[0053] In the clutch device 10 of this embodiment, the end 25D1 of the clutch spring 25 in the first direction D1 is located on the first direction D1 side of the pressure side flange 98. According to the above embodiment, the pressing force from the pressure plate 70 pressed by the clutch spring 25 is efficiently transmitted by the drive side clutch plate 20 and the driven side clutch plate 22.

[0054] In the clutch device 10 of this embodiment, the clutch spring 25 is located between the pressure plate 70 and the centrifugal clutch mechanism 120. According to the above embodiment, power from the centrifugal clutch mechanism 120 can be easily transmitted to the pressure plate 70 via the clutch spring 25.

[0055] In the first embodiment described above, the clutch device 10 was equipped with a clutch spring 25 as an example of a pressing member, but is not limited thereto. For example, as shown in Figure 6, the pressing member 25A may be located on the second direction D2 side of the second flange surface 98D2. Here, the pressing member 25A is provided integrally with the centrifugal clutch mechanism 120. More specifically, the pressing member 25A is provided integrally with the interlocking member 130 of the centrifugal clutch mechanism 120. The pressing member 25A protrudes from the interlocking member 130 toward the first direction D1. The pressing member 25A is configured to press the second flange surface 98D2. The pressing member 25A is configured to press the portion of the second flange surface 98D2 radially outward from the inner diameter side edge 22I of the driven clutch plate 22. According to the above embodiment, the pressing force from the pressure plate 70 pressed by the pressing member 25A is efficiently transmitted by the drive-side clutch plate 20 and the driven-side clutch plate 22. In the example shown in Figure 6, the pressing member 25A is provided integrally with the interlocking member 130, but it may be a separate member from the interlocking member 130. Also, for example, if the pressure-side flange 98 has a projection extending in the second direction D2, the surface of this projection on the second direction D2 side corresponds to the second flange surface 98D2, and the interlocking member 130 corresponds to the pressing member.

[0056] Furthermore, as shown in Figure 7, for example, the pressing member 25B may be located on the side of the second direction D2 side of the base wall 73 D2. Here, the pressing member 25B is provided integrally with the centrifugal clutch mechanism 120. More specifically, the pressing member 25B is provided integrally with the interlocking member 130 of the centrifugal clutch mechanism 120. The pressing member 25B protrudes from the interlocking member 130 toward the first direction D1. The pressing member 25B is configured to press against the surface 73 D2 of the base wall 73 toward the second direction D2. According to the above embodiment, the pressing force from the pressure plate 70 pressed by the pressing member 25B is efficiently transmitted by the drive-side clutch plate 20 and the driven-side clutch plate 22. In the example shown in Figure 7, the pressing member 25B is provided integrally with the interlocking member 130, but it may be a separate member from the interlocking member 130. Furthermore, for example, if the base wall 73 has a projection extending in a second direction D2, the surface of this projection on the second direction D2 side corresponds to the surface 73D2 of the base wall 73 on the second direction D2 side, and the interlocking member 130 corresponds to the pressing member.

[0057] <Second Embodiment> Figure 8 is an enlarged cross-sectional view of a part of the clutch device 210 according to the second embodiment. As shown in Figure 8, the clutch device 210 includes an output shaft 15, a drive-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 240, a pressure plate 70, and a centrifugal clutch mechanism 320.

[0058] As shown in Figure 8, the clutch center 240 comprises a first clutch center 241 and a second clutch center 242. The first clutch center 241 is connected to the output shaft 15. The first clutch center 241 includes an output shaft holding portion 50 to which the output shaft 15 is connected. The first clutch center 241 includes a plurality of center-side cam portions 60 (see Figure 2). The second clutch center 242 is assembled to the first clutch center 241 so as to be movable in the axial direction (i.e., direction D) of the output shaft 15. The end portion 77D1 of the fitting teeth 77 of the pressure plate 70 in the first direction D1 faces the second clutch center 242 side surface 242D2 in the second direction D2. The second clutch center 242 includes a center-side flange 68. The center-side flange 68 is provided on the outer circumference of the second clutch center 242. The center flange 68 is located between the drive-side clutch plate 20 and the driven-side clutch plate 22 and the clutch housing 30 in the axial direction (i.e., direction D) of the output shaft 15. The center flange 68 moves axially (here in the second direction D2) as the weight member 322, described later, moves from a radially inward position PI2 (see Figure 8) to a radially outward position PO2 (see Figure 10), causing the drive-side clutch plate 20 and the driven-side clutch plate 22 to press against each other. The center flange 68 has a pressing surface 68D2 located radially outward from the fitting teeth 77. The pressing surface 68D2 is provided so as to be able to press against the drive-side clutch plate 20. The pressing surface 68D2 may also be provided so as to be able to press against the driven-side clutch plate 22. The center flange 68 is an example of a press-fitting member. The radially inward position PI2 is an example of a first position. The radially outward position PO2 is an example of a second position.

[0059] As shown in Figure 8, the centrifugal clutch mechanism 320 is housed in the clutch housing 30. The centrifugal clutch mechanism 320 is positioned on the first direction D1 side of the clutch center 240. The centrifugal clutch mechanism 320 is held in the clutch housing 30. The centrifugal clutch mechanism 320 is provided to be rotatable integrally with the clutch housing 30. The centrifugal clutch mechanism 320 has a plurality of weight members 322 and a holding member 324. The centrifugal clutch mechanism 320 is configured such that when the weight members 322 are in the radially inward position PI2 (see Figure 8), the pressure force between the drive-side clutch plate 20 and the driven-side clutch plate 22 is released, thereby blocking the transmission of the rotational driving force of the input member to the output shaft 15. The centrifugal clutch mechanism 320 presses the drive-side clutch plate 20 and the driven-side clutch plate 22 together when the weight member 322 is in the radially outward position PO2 (see Figure 10), thereby enabling the rotational driving force of the input member to be transmitted to the output shaft 15.

[0060] The weight member 322 is movable from a first position PI2 (see Figure 8), where the pressure between the drive-side clutch plate 20 and the driven-side clutch plate 22 is released as the centrifugal force increases with the rotation of the clutch housing 30, thereby blocking the transmission of the rotational driving force of the input member to the output shaft 15, to a second position PO2 (see Figure 10), where the drive-side clutch plate 20 and the driven-side clutch plate 22 are pressed together, allowing the rotational driving force of the input member to be transmitted to the output shaft 15. The weight member 322 is housed in a holding member 324. The weight member 322 comprises a main body portion 330 formed in a substantially rectangular parallelepiped shape, a first spherical member 331, and a second spherical member 332. The first spherical member 331 and the second spherical member are attached to the main body portion 330. The first spherical member 331 and the second spherical member are, for example, steel balls. The first spherical member 331 is provided so as to be in contact with the interlocking member 340. The second spherical member 332 is provided so as to be in contact with the holding member 324. The first spherical member 331 and the second spherical member 332 are configured to be rotatable. When no centrifugal force is applied, the weight member 322 is held in a radially inward position PI2 by a spring (not shown). When centrifugal force is applied, the weight member 322 moves radially outward against the biasing force of the spring (not shown) and moves to a radially outward position PO2.

[0061] As shown in Figure 8, the retaining member 324 holds the weight member 322 so that it can move between a radially inward position PI2 and a radially outward position PO2. The retaining member 324 has a housing portion 324A that accommodates the weight member 322. The retaining member 324 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30.

[0062] As shown in Figure 8, the clutch device 210 includes an interlocking member 340. The interlocking member 340 is positioned between the drive-side clutch plate 20 and the driven-side clutch plate 22 and the clutch housing 30 in the axial direction (i.e., direction D) of the output shaft 15. The interlocking member 340 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. As shown in Figure 9, the interlocking member 340 is formed in an annular shape. As shown in Figure 8, the interlocking member 340 includes an inclined surface 340A on which the first spherical member 331 rolls. The inclined surface 340A is tilted toward the first direction D1 as it moves from the radially inward to the radially outward. The interlocking member 340 moves in the axial direction of the output shaft 15 (here in the second direction D2) as the weight member 322 moves from a radially inward position PI2 (see Figure 8) to a radially outward position PO2 (see Figure 10), causing the drive-side clutch plate 20 and the driven-side clutch plate 22 to press against each other. The interlocking member 340 is provided so as to be able to press against the second clutch center 242. The interlocking member 340 and the centrifugal clutch mechanism 320 are provided so as to be able to rotate integrally with the clutch housing 30.

[0063] In the centrifugal clutch mechanism 320 with the above configuration, when no centrifugal force is applied to the weight member 322, the weight member 322 is held at a radially inward position PI2 (see Figure 8), and the contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22 is released. On the other hand, when centrifugal force is applied to the weight member 322, the weight member 322 moves from the radially inward position PI2 to the radially outward position PO2 (see Figure 10). As a result, the interlocking member 340 is pressed by the weight member 322 and moves in the second direction D2. As the interlocking member 340 moves in the second direction D2, the second clutch center 242 is pressed by the interlocking member 340, and the second clutch center 242 moves in the second direction. As a result, the drive-side clutch plate 20 and the driven-side clutch plate 22 are pressed against each other by the pressure-side flange 98 and the center-side flange 68, creating a press-fit state, which allows the rotational driving force of the input member to be transmitted to the output shaft 15.

[0064] In the clutch device 210 of this embodiment, the center flange 68 is located radially outward from the fitting teeth 77 and has a pressing surface 68D2 capable of pressing against the drive clutch plate 20. In this embodiment, the pressing force from the pressing surface 68D2 of the center flange 68, which moves in direction D due to the movement of the weight member 322, is efficiently transmitted to the drive clutch plate 20 and the driven clutch plate 22. This allows the drive clutch plate 20 and the driven clutch plate 22 to be sufficiently pressed against each other.

[0065] In the clutch device 210 of this embodiment, the clutch center 240 has a first clutch center 241 connected to the output shaft 15 and a second clutch center 242 assembled to be movable in direction D relative to the first clutch center 241, and the center-side flange 68 is provided on the outer circumference of the second clutch center 242. According to the above embodiment, the pressing force from the pressing surface 68D2 of the center-side flange 68, which moves in direction D due to the movement of the weight member 322, is efficiently transmitted by the drive-side clutch plate 20 and the driven-side clutch plate 22.

[0066] In the second embodiment described above, the center flange 68 had a pressing surface 68D2 capable of pressing against the drive clutch plate 20, but the invention is not limited to this. For example, the interlocking member 340 may have a pressing surface capable of pressing against the drive clutch plate 20 or the driven clutch plate 22. Also, the center flange 68 and the interlocking member 340 may be formed to be constant.

[0067] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0068] In the embodiments described above, the weight members 122 and 322 were configured to move as a whole between a first position (a radially inward position) and a second position (a radially outward position), but are not limited thereto. For example, a part of the weight member may be configured to swing (move) between the first position and the second position around a pivot axis that is perpendicular to the axis of the output shaft 15 and located radially outward from the axis of the output shaft 15. Furthermore, the ability of the weight member to move from the first position to the second position includes cases where the entire weight member is movable, as described above, and cases where only a part of the weight member is movable (swings).

[0069] 10 Clutch device 15 Output shaft (output member) 20 Drive-side clutch plate 22 Driven-side clutch plate 25 Clutch spring (pressing member) 30 Clutch housing 40 Clutch center 68 Center-side flange (pressure contact member) 70 Pressure plate 73 Base wall 75 Outer peripheral wall 77 Fitting teeth 78 Spline groove 80 Cylindrical part 84 Spring housing part 98 Pressure-side flange 120 Centrifugal clutch mechanism 122 Weight member 124 Holding member 130 Interlocking member

Claims

1. A clutch device for transmitting or interrupting the rotational driving force of an input member to an output member, comprising: a clutch center housed in a clutch housing that holds a plurality of drive-side clutch plates rotated by the rotational drive of the input member, and which rotates together with the output member; a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which holds all of a plurality of driven-side clutch plates arranged alternately with the drive-side clutch plates, and which can press the drive-side clutch plates and the driven-side clutch plates; and a centrifugal clutch mechanism having a plurality of weight members that are movable from a first position in which the contact force between the drive-side clutch plates and the driven-side clutch plates is released as the centrifugal force increases due to the rotation of the clutch housing, thereby interrupting the transmission of the rotational driving force of the input member to the output member, to a second position in which the drive-side clutch plates and the driven-side clutch plates are brought into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member; The centrifugal clutch mechanism comprises a pressing member that presses the pressure plate in conjunction with the operation of the centrifugal clutch mechanism, wherein the direction in which the pressure plate approaches the clutch center is defined as the first direction, and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the pressure plate comprises a base wall, an outer peripheral wall extending from the base wall in the first direction and formed in an annular shape when viewed from the axial direction of the output member, a plurality of fitting teeth arranged in the circumferential direction that hold all of the driven clutch plates and protrude radially outward from the outer peripheral surface of the outer peripheral wall, a plurality of spline grooves formed between adjacent fitting teeth, and a recess formed to recess from the second direction to the first direction and to accommodate the pressing member, wherein the pressing member is configured such that the weight member moves from the first position to the second position to press the pressure plate in the first direction, causing the drive-side clutch plate and the driven-side clutch plate to press against each other.A clutch device in which the end of the pressing member in the first direction is located on the side of the pressure plate in the second direction, further to the second direction than the end of the fitting tooth in the first direction, and further to the first direction than the axial center of the fitting tooth.

2. The clutch device according to claim 1, wherein the pressure plate comprises a flange extending radially outward from the outer peripheral edge of the base wall and having a first flange surface located on the first direction side and a second flange surface located on the second direction side, the first flange surface being configured to press against the drive-side clutch plate and the driven-side clutch plate, and the pressing member being located on the second direction side of the second flange surface and configured to press against the second flange surface.

3. The clutch device according to claim 2, wherein the pressing member is configured to press the portion of the second flange surface that is radially outward from the inner diameter side edge of the driven clutch plate.

4. The clutch device according to claim 1, wherein the pressure plate comprises a flange extending radially outward from the outer peripheral edge of the base wall and having a first flange surface located on the first direction side and a second flange surface located on the second direction side, the first flange surface being configured to press against the drive-side clutch plate and the driven-side clutch plate, and the pressing member being located on the second direction side of the base wall and configured to press against the second direction side of the base wall.

5. The clutch device according to claim 1, wherein the pressure plate comprises a flange extending radially outward from the outer peripheral edge of the base wall and having a first flange surface located on the first direction side and a second flange surface located on the second direction side, and the end of the pressing member in the first direction is located on the first direction side of the flange.

6. The clutch device according to claim 1, wherein the pressing member is a clutch spring located between the pressure plate and the centrifugal clutch mechanism.

7. A clutch device for transmitting or interrupting the rotational driving force of an input member to an output member, comprising: a clutch center housed in a clutch housing that holds a plurality of drive-side clutch plates rotated by the rotational drive of the input member, and which rotates together with the output member; a pressure plate provided so as to be able to approach or move away from the clutch center and to be rotatable relative to it, and which holds all of a plurality of driven-side clutch plates arranged alternately with the drive-side clutch plates, and which can press the drive-side clutch plates and the driven-side clutch plates; and a centrifugal clutch mechanism having a plurality of weight members that are movable from a first position in which the contact force between the drive-side clutch plates and the driven-side clutch plates is released as the centrifugal force increases due to the rotation of the clutch housing, thereby interrupting the transmission of the rotational driving force of the input member to the output member, to a second position in which the drive-side clutch plates and the driven-side clutch plates are brought into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member; The output member comprises a pressure contact member positioned between the drive-side clutch plate and the driven-side clutch plate and the clutch housing in the axial direction of the output member, wherein when the direction in which the pressure plate approaches the clutch center is defined as the first direction and the direction in which the pressure plate moves away from the clutch center is defined as the second direction, the pressure contact member is configured to move axially in the second direction as the weight member moves from the first position to the second position, thereby bringing the drive-side clutch plate and the driven-side clutch plate into contact, the pressure plate comprises an outer peripheral wall extending in the axial direction of the output member and formed in an annular shape when viewed from the axial direction of the output member, a plurality of fitting teeth arranged in the circumferential direction that hold all of the driven-side clutch plates and protrude radially outward from the outer peripheral surface of the outer peripheral wall, and a plurality of spline grooves formed between adjacent fitting teeth, the pressure contact member is A clutch device having a pressing surface located radially outward from the aforementioned mating teeth and capable of pressing against the drive-side clutch plate or the driven-side clutch plate.

8. The clutch device according to claim 7, wherein, when the weight member is in the first position, the end of the mating tooth in the first direction is located on the side in the first direction more toward the second direction than the side of the drive clutch plate that is located furthest toward the first direction among the plurality of drive clutch plates.

9. The clutch device according to claim 7, wherein the clutch center comprises a first clutch center connected to the output member and a second clutch center assembled to be movable in the axial direction relative to the first clutch center, and the pressure contact member is provided on the outer circumference of the second clutch center.

10. The clutch device according to claim 9, wherein the end of the mating tooth in the first direction faces the second direction side surface of the second clutch center.

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