Clutch device

Abstract

A clutch device 10 comprises a centrifugal clutch mechanism 120 having a weight 122 movable from an inner-diameter-side position PI where transmission of a rotational driving force of an input member to an output shaft 15 can be blocked, to an outer-diameter-side position PO where the rotational driving force can be transmitted to the output shaft 15. Throughout an entire process in which the one weight 122 moves from the inner-diameter-side position PI to the outer-diameter-side position PO, a straight line LS passing through a center 122C of the one weight 122 and a center 15C of the output shaft 15 passes through a pressure-side slipper cam surface 90S when viewed in the axial direction of the output shaft 15.

Description

Clutch device

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

[0002] For example, in Patent Document 1, as the centrifugal force increases with the rotation of the clutch housing, a weight that moves from the first position (for example, the inner diameter side position) to the second position (for example, the outer diameter side position) is provided to press the driving side clutch plate and the driven side clutch plate together. A clutch device is disclosed. According to such a conventional clutch device, when the clutch housing rotates with the driving of a driving source such as an engine, centrifugal force can be applied to the weight, and the driving force of the engine can be transmitted to the wheels by pressing the driving side clutch plate and the driven side clutch plate together.

[0003] Further, the clutch center and the pressure plate of the clutch device of Patent Document 1 generate a force in the direction from the pressure plate toward the clutch center when the rotational driving force of the engine can be transmitted to the output shaft, increasing the pressing force between the driving side clutch plate and the driven side clutch plate. It has an assist cam surface, and a slipper cam surface that separates the pressure plate from the clutch center when the rotational speed of the clutch center exceeds the rotational speed of the pressure plate, reducing the pressing force between the driving side clutch plate and the driven side clutch plate.

[0004] Japanese Patent Application Laid-Open No. 2020-90988

[0005] By the way, in a clutch device provided with a weight and a slipper cam surface, when the clutch center and the pressure plate rotate relative to each other, the driving side clutch plate and the driven side clutch plate are separated early through the slipper cam surfaces of the clutch center and the pressure plate, and the rotational driving force from the input member to the output member is reduced early. It is desired.

[0006] The present invention has been made in view of this point, and its object is to provide a clutch device that can separate the driving side clutch plate and the driven side clutch plate early and reduce the transmission of the rotational driving force from the input member to the output member early.

[0007] 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, 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 provided so as to be able to approach and move away from the clutch center, which holds at least one 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 plate and the driven-side clutch plate; and a centrifugal clutch mechanism having a plurality of weights that is movable from a first position in which the contact 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 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 plate and the driven-side clutch plate are brought into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, wherein the clutch center is The pressure plate is provided with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate when it rotates relative to the clutch center, and the pressure plate is provided with a pressure-side cam portion having a pressure-side slipper cam surface that is configured to be able to contact the center-side slipper cam surface when it rotates relative to the clutch center and that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate, and the weight is configured to press against the drive-side clutch plate and the driven-side clutch plate as it moves from the first position to the second position, and throughout the entire process of one of the weights moving from the first position to the second position, the straight line passing between the center of one of the weights and the center of the output member, when viewed in the axial direction of the output member, passes through the pressure-side slipper cam surface.

[0008] According to the clutch device of the present invention, throughout the entire process of one weight moving from a first position to a second position, the straight line passing between the center of one weight and the center of the output member, when viewed in the axial direction of the output member, passes through the pressure-side slipper cam surface. In this embodiment, when the clutch center rotates relative to the pressure plate, one weight is efficiently pressed in the direction from the second position to the first position via the pressure-side slipper cam surface. This allows the drive-side clutch plate and the driven-side clutch plate to be separated early, thereby reducing the transmission of rotational driving force from the input member to the output member at an early stage.

[0009] 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 that rotates together with the output member; and a pressure plate that is provided so as to be able to approach and separate from the clutch center and holds at least one of a plurality of driven-side clutch plates that are alternately arranged with the drive-side clutch plates, and that can press the drive-side clutch plate and the driven-side clutch plate. The clutch center comprises a centrifugal clutch mechanism having a plurality of weights that can move from an inner diameter position, which releases the contact force between the drive-side clutch plate and the driven-side clutch plate 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 an outer diameter position, which brings the drive-side clutch plate and the driven-side clutch plate into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, and the clutch center rotates relative to the pressure plate, the drive-side clutch plate The pressure plate is provided with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the driven clutch plate and the driven clutch plate, and the pressure plate is provided with a pressure-side cam portion having a pressure-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the driven clutch plate and the driven clutch plate, and the weight is inside The drive clutch plate and the driven clutch plate are configured to press against each other as the weight moves from the radial side position to the outer diameter side position, and when the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction, then throughout the entire process in which one of the weights moves from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the pressure-side slipper cam surface is,It is located in the region enclosed by a first tangent line that passes through the center of the output member and touches the first circumferential portion of the one weight, and a second tangent line that passes through the center of the output member and touches the second circumferential portion of the one weight.

[0010] In another clutch device according to the present invention, throughout the entire process in which one weight moves from the inner diameter side position to the outer diameter side position, at least a portion of the pressure-side slipper cam surface, when viewed in the axial direction of the output member, is located in the region enclosed by the first tangent and the second tangent. According to the above embodiment, when the clutch center rotates relative to the pressure plate, one weight is efficiently pressed in the direction from the outer diameter side position to the inner diameter side position via the pressure-side slipper cam surface. This allows the drive-side clutch plate and the driven-side clutch plate to be separated early, thereby reducing the transmission of rotational driving force from the input member to the output member at an early stage.

[0011] 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 provided so as to be able to approach and move away from the clutch center, which holds at least one 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 plate and the driven-side clutch plate; and a centrifugal clutch mechanism having a plurality of weights that is movable from a first position in which the contact 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 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 plate and the driven-side clutch plate are brought into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, wherein the clutch center rotates relative to the pressure plate. The clutch is equipped with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate, and the pressure plate is configured to be able to contact the center-side slipper cam surface when it rotates relative to the clutch center and has a pressure-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate. The drive clutch plate and the driven clutch plate are pressed together as the weight moves from the first position to the second position, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the first pressure-side cam portion is defined as the second circumferential direction, and throughout the entire process of one of the weights moving from the first position to the second position, when viewed in the axial direction of the output member,The first circumferential edge of the pressure-side slipper cam surface is located on the first circumferential side of a straight line passing through the center of one of the weights and the center of the output member, and the second circumferential edge of the pressure-side slipper cam surface is located on the second circumferential side of the straight line, and the pressure-side slipper cam surface is provided such that the straight line passes through the pressure-side slipper cam surface.

[0012] In another clutch device according to the present invention, the pressure-side slipper cam surface is provided such that, when viewed in the axial direction, a straight line passes through the pressure-side slipper cam surface throughout the entire process of one weight moving from a first position to a second position. According to the above embodiment, when the clutch center rotates relative to the pressure plate, one weight is efficiently pressed in the direction from the second position to the first position via the pressure-side slipper cam surface. This makes it possible to separate the drive-side clutch plate and the driven-side clutch plate early and reduce the transmission of rotational driving force from the input member to the output member early.

[0013] 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 provided so as to be able to approach and move away from the clutch center, which holds at least one 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 plate and the driven-side clutch plate; and a centrifugal clutch mechanism having a plurality of weights that can move from an inner diameter side position that can release the contact force between the drive-side clutch plate and the driven-side clutch plate 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 an outer diameter side position that brings the drive-side clutch plate and the driven-side clutch plate into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, wherein the clutch center rotates relative to the pressure plate, The clutch is provided with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate, and the pressure plate is configured to be able to contact the center-side slipper cam surface when it rotates relative to the clutch center and has a pressure-side cam portion having a pressure-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate. The weight is configured to press against the drive clutch plate and the driven clutch plate as it moves from the inner diameter side position to the outer diameter side position, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction, and throughout the entire process of one of the weights moving from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, with respect to the circumferential direction,At least a portion of the region enclosed by the first slipper-side straight line passing through the center of the output member and the first circumferential edge of the pressure-side slipper cam surface, and the second slipper-side straight line passing through the center of the output member and the second circumferential edge of the pressure-side slipper cam surface, is configured to overlap with the region enclosed by the first tangent line passing through the center of the output member and touching the first circumferential portion of one of the weights, and the second tangent line passing through the center of the output member and touching the second circumferential portion of one of the weights.

[0014] In another clutch device according to the present invention, throughout the entire process in which one weight moves from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the region enclosed by the first slipper side straight line and the second slipper side straight line overlaps with the region enclosed by the first tangent and the second tangent. According to the above embodiment, when the clutch center rotates relative to the pressure plate, one weight is efficiently pressed in the direction from the second position to the first position via the pressure side slipper cam surface. This makes it possible to separate the drive side clutch plate and the driven side clutch plate early and reduce the transmission of rotational driving force from the input member to the output member early.

[0015] 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 provided so as to be able to approach and move away from the clutch center, which holds at least one of a plurality of driven-side clutch plates arranged alternately with the drive-side clutch plates, and which can press the drive-side clutch plate and the driven-side clutch plate; and a centrifugal clutch mechanism having a plurality of weights that can move from a first position in which the contact 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 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 plate and the driven-side clutch plate are brought into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, wherein the clutch center rotates relative to the pressure plate, The clutch is equipped with a center-side cam portion having a center-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the driving clutch plate and the driven clutch plate, and the pressure plate is configured to be able to contact the center-side assist cam surface when it rotates relative to the clutch center and has a pressure-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the driving clutch plate and the driven clutch plate. The device is equipped with a pressure-side cam portion, and is configured such that the drive-side clutch plate and the driven-side clutch plate are pressed together when the weight moves from the first position to the second position, and when the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the first pressure-side cam portion is defined as the second circumferential direction, then, throughout the entire process of one of the weights moving from the first position to the second position, when viewed in the axial direction of the output member,The pressure-side assist cam surface is provided such that the first circumferential edge of the pressure-side assist cam surface is located on the first circumferential side of a straight line passing through the center of one of the weights and the center of the output member, the second circumferential edge of the pressure-side assist cam surface is located on the second circumferential side of the straight line, and the straight line passes through the pressure-side assist cam surface.

[0016] In another clutch device according to the present invention, the pressure-side assist cam surface is provided such that, when viewed in the axial direction, a straight line passes through the pressure-side assist cam surface throughout the entire process of a weight moving from a first position to a second position. According to the above embodiment, the pressure-side assist cam surface is pressed more reliably by the weight toward the center-side assist cam surface, so that the rotational driving force of the input member can be transmitted to the output member more reliably via the pressure-side assist cam surface and the center-side assist cam surface.

[0017] 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 that rotates together with the output member; and a pressure plate that is provided so as to be able to approach and separate from the clutch center and holds at least one of a plurality of driven-side clutch plates that are alternately arranged with the drive-side clutch plates, and that can press the drive-side clutch plate and the driven-side clutch plate. The clutch center comprises a clutch housing and a centrifugal clutch mechanism having a plurality of weights that can move from an inner diameter position, which releases the contact force between the drive-side clutch plate and the driven-side clutch plate 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 an outer diameter position, which brings the drive-side clutch plate and the driven-side clutch plate into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, wherein the clutch center rotates relative to the pressure plate, and the drive-side clutch... The clutch is provided with a center-side cam portion having a center-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate, and the pressure plate is configured to be able to contact the center-side assist cam surface when it rotates relative to the clutch center and has a pressure-side cam having a pressure-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate. The device is configured such that the drive clutch plate and the driven clutch plate are pressed together as the weight moves from the inner diameter side position to the outer diameter side position, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction, and throughout the entire process of one of the weights moving from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, with respect to the circumferential direction,At least a portion of the region enclosed by the first assist-side straight line passing through the center of the output member and the first circumferential edge of the pressure-side assist cam surface, and the second assist-side straight line passing through the center of the output member and the second circumferential edge of the pressure-side assist cam surface, is configured to overlap with the region enclosed by the first tangent line passing through the center of the output member and touching the first circumferential portion of one of the weights, and the second tangent line passing through the center of the output member and touching the second circumferential portion of one of the weights.

[0018] In another clutch device according to the present invention, throughout the entire process in which one weight moves from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the region enclosed by the first assist-side straight line and the second assist-side straight line overlaps with the region enclosed by the first tangent and the second tangent. According to the above embodiment, the pressure-side assist cam surface is pressed more reliably by the weight towards the center-side assist cam surface, so that the rotational driving force of the input member can be transmitted to the output member more reliably via the pressure-side assist cam surface and the center-side assist cam surface.

[0019] According to the present invention, it is possible to provide a clutch device that can reduce the transmission of rotational driving force from an input member to an output member at an early stage by separating the drive-side clutch plate and the driven-side clutch plate early.

[0020] Figure 1 is a cross-sectional view of a clutch device according to one embodiment. Figure 2 is a cross-sectional view showing a part of the clutch device according to one embodiment. Figure 3 is an exploded perspective view of the first clutch center, second clutch center, pressure plate, and bearing retaining member according to one embodiment. Figure 4 is an exploded perspective view of the first clutch center, second clutch center, pressure plate, and bearing retaining member according to one 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 plan view showing the state in which the weight housed in the housing member according to one embodiment is located at the inner diameter side position. Figure 7 is a plan view showing the state in which the weight housed in the housing member according to one embodiment is located at the outer diameter side position. Figure 8 is a plan view showing the positional relationship between the pressure-side assist cam surface and the weight located at the inner diameter side position according to one embodiment. Figure 9 is a plan view showing the positional relationship between the pressure-side assist cam surface and the weight located at the outer diameter side position according to one embodiment. Figure 10 is a plan view showing the positional relationship between the pressure-side slipper cam surface and the weight located at the inner diameter side according to one embodiment. Figure 11 is a plan view showing the positional relationship between the pressure-side slipper cam surface and the weight located at the outer diameter side according to one embodiment.

[0021] 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.

[0022] Figure 1 is a cross-sectional view of the clutch device 10. 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 the input member (crankshaft) of the drive source (e.g., engine) of a motorcycle to the output shaft 15. The clutch device 10 is a device for transmitting or interrupting the rotational driving force of the input member to the drive wheel (rear wheel) via the output shaft 15. The clutch device 10 is located between the drive source and the transmission. The output shaft 15 is an example of an output member.

[0023] 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 clutch housing 30, the pressure plate 70, and the clutch center 40 rotate in a first circumferential direction S1 during normal operation (i.e., the direction from the center-side assist cam surface 60A to the center-side slipper cam surface 60S of one center-side cam portion 60). 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.

[0024] 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, a bearing holding member 100, and a centrifugal clutch mechanism 120.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] As shown in Figure 1, an input gear 35 is provided on the bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by rivets 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates due to the rotational drive of the engine's input member. The input gear 35 rotates independently of the output shaft 15 and integrally with the clutch housing 30.

[0029] 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.

[0030] 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.

[0031] As shown in Figure 1, the clutch center 40 is housed in the clutch housing 30. The clutch center 40 is positioned concentrically with the clutch housing 30. The clutch center 40 holds a plurality of driven clutch plates 22. The driven clutch plates 22 are arranged alternately with the driven clutch plates 20 in direction D. The clutch center 40 is rotationally driven together with the output shaft 15. As shown in Figure 2, the clutch center 40 comprises a first clutch center 41 and a second clutch center 51. The first clutch center 41 and the second clutch center 51 are assembled with each other. The second clutch center 51 engages with the first clutch center 41. The second clutch center 51 is externally fitted onto the first clutch center 41.

[0032] As shown in Figure 3, the first clutch center 41 has a main body 42 and a center-side flange 68 extending radially outward from the outer peripheral edge of the main body 42. The main body 42 has a portion that protrudes in the second direction D2 from the center-side flange 68. The first clutch center 41 is rotationally driven together with the output shaft 15.

[0033] As shown in Figure 3, the main body 42 comprises an output shaft holding portion 50 and a plurality of center-side cam portions 60. 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.

[0034] As shown in Figure 3, 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 against 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.

[0035] As shown in Figure 3, the output shaft holder 50 is formed in a cylindrical shape. The output shaft holder 50 has an insertion hole 44 into which the output shaft 15 (see Figure 1) is inserted and spline fitted. The insertion hole 44 is formed through the main body 42. Multiple spline grooves are formed along the axial direction on the inner circumferential surface of the output shaft holder 50 that forms the insertion hole 44. The output shaft 15 is connected to the output shaft holder 50.

[0036] 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 fully engaged and the state in which the clutch is fully disengaged. As shown in Figure 3, 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.

[0037] As shown in Figure 3, the center-side cam portion 60 is located radially outward of 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 (for example, the first clutch center 41) rotates relative to the pressure plate 70 when accelerating (for example, when the rotational speed of the pressure plate 70 exceeds the rotational speed of the clutch center 40). 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-side 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-side clutch plate 20 and the driven-side clutch plate 22 when the clutch center 40 (for example, the first clutch center 41) rotates relative to the pressure plate 70 when deceleration occurs (for example, when the rotational speed of the clutch center 40 exceeds the rotational speed of the pressure plate 70). In adjacent center-side cam portions 60 with respect to 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 facing each other in the circumferential direction S.

[0038] As shown in Figures 3 and 4, the first clutch center 41 has a center-side cam hole 43H that penetrates a portion of the main body 42. The center-side cam hole 43H penetrates the main body 42 in 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 of one center-side cam portion 60 and the center-side slipper cam surface 60S of the other 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.

[0039] As shown in Figure 3, the first clutch center 41 has a plurality of engagement grooves 49. The engagement grooves 49 are formed in the center-side cam portion 60. The engagement grooves 49 are recessed radially inward from the outer circumferential surface of the center-side cam portion 60. The engagement grooves 49 are recessed in the first direction D1 from the surface 60D2 in the second direction D2 of the center-side cam portion 60. In this embodiment, one center-side cam portion 60 has two engagement grooves 49 aligned in the circumferential direction S.

[0040] As shown in Figures 3 and 4, the second clutch center 51 has an annular outer wall 52. The second clutch center 51 holds a drive-side clutch plate 20 and a plurality of driven-side clutch plates 22 that are alternately arranged in direction D.

[0041] As shown in Figures 3 and 4, a spline fitting portion 56 is provided on the outer circumferential surface of the outer circumferential wall 52. The spline fitting portion 56 has a plurality of center-side fitting teeth 57 extending in the axial direction (i.e., direction D) of the second clutch center 51 along the outer circumferential surface of the outer circumferential wall 52, and a plurality of spline grooves 58 formed between adjacent center-side fitting teeth 57 and extending in the axial direction (i.e., direction D) of the second clutch center 51. The center-side fitting teeth 57 hold the driven clutch plate 22. The plurality of center-side fitting teeth 57 are arranged in the circumferential direction S. The plurality of center-side fitting teeth 57 are formed at equal intervals in the circumferential direction S. The plurality of center-side fitting teeth 57 are formed to have the same shape. The center-side fitting teeth 57 protrude radially outward from the outer circumferential surface of the outer circumferential wall 52. The plurality of spline grooves 58 are arranged in the circumferential direction S. Multiple spline grooves 58 are formed at equal intervals in the circumferential direction S. Multiple spline grooves 58 are formed in the same shape.

[0042] The driven clutch plate 22 is held by the spline fitting portion 56 of the second clutch center 51 and the pressure plate 70. A portion of the driven clutch plate 22 is held by spline fitting to the center-side fitting teeth 57 and spline groove 58 of the second clutch center 51. Another portion of the driven clutch plate 22 is held by the pressure-side fitting teeth 87 (see Figure 4), which will be described later, of the pressure plate 70. The driven clutch plate 22 is provided so as to be displaceable along the axial direction (i.e., direction D) of the clutch center 40. The driven clutch plate 22 is provided so as to be rotatable integrally with the clutch center 40. 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.

[0043] The driven-side clutch plate 22 is a member that is pressed against the drive-side clutch plate 20. The driven-side clutch plate 22 is formed in an annular shape. The driven-side clutch plate 22 is formed by punching and shaping a thin plate material made of SPCC material into an annular shape. Note that the friction material provided on the drive-side clutch plate 20 may be provided on the driven-side clutch plate 22 instead of the drive-side clutch plate 20, or may be provided on each of the drive-side clutch plate 20 and the driven-side clutch plate 22.

[0044] As shown in FIGS. 3 and 4, the second clutch center 51 has a plurality of engaging protrusions 55. The engaging protrusions 55 engage with the engaging grooves 49 (see FIG. 3) of the first clutch center 41. The engaging protrusions 55 are formed on the inner peripheral surface of the outer peripheral wall 52. The engaging protrusions 55 protrude radially inward from the inner peripheral surface of the outer peripheral wall 52. When the drive-side clutch plate 20 and the driven-side clutch plate 22 are pressed against each other when accelerating or the like, the engaging protrusions 55 and the engaging grooves 49 abut on the surface on the first circumferential direction S1 side, so that the rotational driving force of the second clutch center 51 is transmitted to the first clutch center 41. On the other hand, when back torque occurs when decelerating or the like, the engaging protrusions 55 and the engaging grooves 49 abut on the surface on the second circumferential direction S2 side, so that the relative rotation of the second clutch center 51 with respect to the first clutch center 41 is restricted. Thereby, the amount of movement of the second clutch center 51 can be restricted.

[0045] As shown in FIG. 1, the pressure plate 70 is housed in the clutch housing 30. The pressure plate 70 is located on the second direction D2 side with respect to the clutch center 40. The pressure plate 70 is provided so as to be able to approach and separate from the clutch center 40. The pressure plate 70 is provided so as to be relatively rotatable with respect to the clutch center 40. The pressure plate 70 is configured to be able to press the driving-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 FIGS. 3 and 4, the pressure plate 70 has a main body 72 and a pressure-side flange 98 extending radially outward from the outer peripheral edge of the main body 72. The main body 72 has a portion protruding in the first direction D1 with respect to the pressure-side flange 98. The pressure plate 70 holds a part of the plurality of driven-side clutch plates 22 alternately arranged with the driving-side clutch plate 20 in the direction D.

[0046] As shown in FIG. 4, the main body 72 includes an annular base wall 73, a cylindrical portion 80 provided at the center of the base wall 73, a plurality of pressure-side cam portions 90 formed on the base wall 73, and a spring housing portion 89 (see FIG. 3).

[0047] As shown in FIGS. 3 and 4, 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 outside the pressure-side cam portion 90. The pressure-side flange 98 sandwiches the driving-side clutch plate 20 and the driven-side clutch plate 22 together with the center-side flange 68 of the clutch center 40. The pressure-side flange 98 is provided so as to be able to press the driving-side clutch plate 20 and the driven-side clutch plate 22. The pressure-side flange 98 is a member that applies a pressing force to the driving-side clutch plate 20 and the driven-side clutch plate 22.

[0048] The cylindrical portion 80 is formed in a cylindrical shape. As shown in FIG. 1, a bearing holding member 100 is inserted into the cylindrical portion 80.

[0049] 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 4, the pressure-side cam portion 90 is formed to protrude in the first direction D1 from the pressure-side flange 98. The pressure-side cam portion 90 is formed to protrude in the first direction D1 from the base wall 73. 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.

[0050] As shown in Figure 4, the pressure-side cam portion 90 is located radially outward of the cylindrical portion 80. The pressure-side cam portion 90 has a pressure-side assist cam surface 90A (see also Figure 3) and a pressure-side slipper cam surface 90S (see also Figure 3). 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 (for example, when the rotational speed of the pressure plate 70 exceeds the rotational speed of the clutch center 40). 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 when deceleration occurs (for example, when the rotational speed of the clutch center 40 exceeds the rotational speed of the pressure plate 70). 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.

[0051] 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 (for example, the first clutch center 41), a rotational force in the first 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.

[0052] 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, generating back torque, a first rotational force in the circumferential direction S1 is applied to the clutch center 40 (for example, the first clutch center 41), 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.

[0053] As shown in Figures 3 and 4, 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 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.

[0054] As shown in Figure 4, the pressure plate 70 is provided with a plurality of pressure-side fitting teeth 87 located on the pressure-side flange 98. The pressure-side fitting teeth 87 hold the driven-side clutch plate 22. The pressure-side fitting teeth 87 protrude from the pressure-side flange 98 toward a first direction D1. The pressure-side fitting teeth 87 are located radially outward from the cylindrical portion 80. The pressure-side fitting teeth 87 are located radially outward from the pressure-side cam portion 90. The plurality of pressure-side fitting teeth 87 are arranged in the circumferential direction S. The plurality of pressure-side fitting teeth 87 are arranged at equal intervals in the circumferential direction S.

[0055] As shown in Figure 3, the spring housing portion 89 is formed in the pressure-side cam portion 90. The spring housing portion 89 is formed to be recessed from the second direction D2 to the first direction D1. The spring housing portion 89 is formed in a circular shape. As shown in Figure 1, the spring housing portion 89 houses the clutch spring 25.

[0056] 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 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 122, described later, moves). The clutch spring 25 is configured to press the pressure plate 70 in the first direction D1 as the weight 122 moves from the inner diameter side position PI (see Figure 1) to the outer diameter side position PO (see Figure 7), causing the drive-side clutch plate 20 and the driven-side clutch plate 22 to come into contact.

[0057] As shown in Figure 1, the bearing retaining member 100 is located radially inward from the cylindrical portion 80. The bearing retaining member 100 is fitted inside the first clutch center 41. The bearing retaining member 100 accommodates the tip portion 15T (see Figure 1) of the output shaft 15. The release bearing 18 (see Figure 1) is housed in the bearing retaining member 100. The bearing retaining member 100 holds the release bearing 18. The bearing retaining member 100 is the part that receives the pressing force from the push member 16B. When the bearing retaining member 100 is pressed by the push member 16B, the bearing retaining member 100 moves the pressure plate 70 in the second direction D2. This releases the pressure between the drive-side clutch plate 20 and the driven-side clutch plate 22, and the clutch is disengaged (i.e., the transmission of rotational driving force is interrupted). The bearing retaining member 100 is the part that receives the clutch oil that has leaked out from the tip portion 15T of the output shaft 15.

[0058] As shown in Figure 1, the clutch device 10 is equipped with a release spring 102. The release spring 102 is provided between the bearing retaining member 100 and the pressure plate 70. The release spring 102 biases the pressure plate 70 in the second direction D2.

[0059] As shown in Figure 1, the centrifugal clutch mechanism 120 is provided at the end 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 has a plurality of weights 122, a housing member 124 that houses the weights 122, and an interlocking member 130. The centrifugal clutch mechanism 120 is configured to release the contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the weights 122 are in the inner diameter side position PI (see also Figure 6), thereby blocking the transmission of the rotational driving force of the input member to the output shaft 15. The centrifugal clutch mechanism 120 presses the drive-side clutch plate 20 and the driven-side clutch plate 22 together when the weight 122 is in the outer diameter position PO (see Figure 7), thereby enabling the rotational driving force of the input member to be transmitted to the output shaft 15. The inner diameter position PI is an example of a first position. The outer diameter position PO is an example of a second position.

[0060] The weight 122 is provided to be movable from an inner diameter position PI (see Figures 1 and 6), which releases the pressure between the drive-side clutch plate 20 and the driven-side clutch plate 22 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 an outer diameter position PO (see Figure 7), which presses the drive-side clutch plate 20 and the driven-side clutch plate 22 together, allowing the rotational driving force of the input member to be transmitted to the output shaft 15. The weight 122 is formed in a spherical shape. The weight 122 is, for example, a steel ball. When no centrifugal force is applied, the weight 122 is held at the inner diameter position PI by the release spring 102. When centrifugal force is applied, the weight 122 moves radially outward against the biasing force of the release spring 102 and moves to the outer diameter position PO. When the weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, the pressure plate 70 is configured to be pressed by the weight 122 in the direction toward the clutch center 40 (in this case, the first direction D1).

[0061] As shown in Figure 1, the housing member 124 holds the weight 122 so that it can move between an inner diameter position PI and an outer diameter position PO. As shown in Figure 6, the housing member 124 has a plurality of grooves 124A that extend radially from the center 15C of the output shaft 15 when viewed in the axial direction of the output shaft 15. The weight 122 is positioned within the grooves 124A. The grooves 124A are provided with contact surfaces 124B that the weight 122 contacts when it moves radially (for example, when it moves from an inner diameter position PI to an outer diameter position PO). The contact surfaces 124B are inclined toward the first direction D1 as they move from the radially inward to the radially outward. The housing member 124 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. The housing member 124 rotates integrally with the clutch housing 30. The housing member 124 is located on the opposite side of the pressure-side assist cam surface 90A with respect to the axial direction (i.e., direction D) of the output shaft 15, with the weight 122 in between. In this embodiment, the housing member 124 is located on the second direction D2 side of the pressure-side assist cam surface 90A.

[0062] As shown in Figure 1, the interlocking member 130 is attached to the housing member 124. The interlocking member 130 is provided so as to be displaceable in the axial direction (i.e., direction D) of the clutch housing 30 relative to the housing member 124. The interlocking member 130 and the housing 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 via a thrust bearing 105 and a pressure contact plate 107. The interlocking member 130, together with the housing member 124, holds the weight 122. The interlocking member 130 is configured to move in a first direction D1 as the weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, thereby pressing the clutch spring 25 in the first direction D1.

[0063] As shown in Figure 8, when the weight 122 is located at the inner diameter side position PI, the straight line LS passing through the center 122C of the weight 122 and the center 15C of the output shaft 15, when viewed in the axial direction of the output shaft 15, passes through the pressure-side assist cam surface 90A. In this embodiment, the straight line LS is also the center line of the groove 124A (see Figure 6). As shown in Figure 6, when the weight 122 is located at the inner diameter side position PI, the straight line LS passes through the groove 124A when viewed in the axial direction of the output shaft 15. As shown in Figure 8, when the weight 122 is located at the inner diameter side position PI, at least a portion of the weight 122 overlaps with the pressure-side assist cam surface 90A when viewed in the axial direction of the output shaft 15. When the weight 122 is located at the inner diameter side position PI, when viewed in the axial direction of the output shaft 15, at least a portion of the pressure-side assist cam surface 90A is located in the region enclosed by a first tangent line LT1 that passes through the center 15C of the output shaft 15 and is in contact with the first circumferential S1 side portion of the weight 122, and a second tangent line LT2 that passes through the center 15C of the output shaft 15 and is in contact with the second circumferential S2 side portion of the weight 122.

[0064] As shown in Figure 9, when the weight 122 is located at the outer diameter side position PO, the straight line LS passing through the center 122C of the weight 122 and the center 15C of the output shaft 15, when viewed in the axial direction of the output shaft 15, passes through the pressure-side assist cam surface 90A. During the process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, the straight line LS passes through the pressure-side assist cam surface 90A. The straight line LS may pass through the pressure-side assist cam surface 90A throughout the entire process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO. In this embodiment, the straight line LS passes through the pressure-side assist cam surface 90A throughout the entire process of a single weight 122 moving from the inner diameter side position PI to the outer diameter side position PO. Throughout the entire process of the weight 122 moving from the inner diameter position PI to the outer diameter position PO, the first circumferential edge 90AS1 of the pressure-side assist cam surface 90A is located on the first circumferential direction S1 side of the straight line LS, and the second circumferential edge 90AS2 of the pressure-side assist cam surface 90A is located on the second circumferential direction S2 side of the straight line LS, and the pressure-side assist cam surface 90A is provided such that the straight line LS passes through the pressure-side assist cam surface 90A. As a result, the pressure-side assist cam surface 90A is reliably pressed by the weight 122 on the center-side assist cam surface 60A side (for example, the first direction D1 side), so that the rotational driving force of the input shaft can be more reliably transmitted to the output shaft 15 via the pressure-side assist cam surface 90A and the center-side assist cam surface 60A. When the weight 122 is positioned at the outer diameter side position PO, when viewed in the axial direction of the output shaft 15, at least a portion of the pressure-side assist cam surface 90A is located in the region enclosed by a first tangent line LT1 that passes through the center 15C of the output shaft 15 and is in contact with the first circumferential S1 side portion of the weight 122, and a second tangent line LT2 that passes through the center 15C of the output shaft 15 and is in contact with the second circumferential S2 side portion of the weight 122. During the process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, at least a portion of the pressure-side assist cam surface 90A is located in the region enclosed by the first tangent line LT1 and the second tangent line LT2.Throughout the entire process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, at least a portion of the pressure-side assist cam surface 90A may be located in the region enclosed by the first tangent LT1 and the second tangent LT2. In this embodiment, throughout the entire process of a single weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, at least a portion (e.g., all) of the region enclosed by the first assist-side straight line LA1 passing through the center 15C of the output shaft 15 and the first circumferential edge 90AS1 of the pressure-side assist cam surface 90A, and the second assist-side straight line LA2 passing through the center 15C of the output shaft 15 and the second circumferential edge 90AS2 of the pressure-side assist cam surface 90A, is configured to overlap with the region enclosed by the first tangent LT1 and the second tangent LT2. As a result, the pressure-side assist cam surface 90A is more reliably pressed by the weight 122 towards the center-side assist cam surface 60A (for example, towards the first direction D1), and the rotational driving force of the input shaft can be more reliably transmitted to the output shaft 15 via the pressure-side assist cam surface 90A and the center-side assist cam surface 60A.

[0065] As shown in Figure 10, when the weight 122 is located at the inner diameter side position PI, the straight line LS passing through the center 122C of the weight 122 and the center 15C of the output shaft 15, when viewed in the axial direction of the output shaft 15, passes through the pressure side slipper cam surface 90S. When the weight 122 is located at the inner diameter side position PI, at least a portion of the weight 122 overlaps with the pressure side slipper cam surface 90S when viewed in the axial direction of the output shaft 15. When the weight 122 is located at the inner diameter side position PI, when viewed in the axial direction of the output shaft 15, at least a portion of the pressure-side slipper cam surface 90S is located in the region enclosed by a first tangent line LT1 that passes through the center 15C of the output shaft 15 and is in contact with the first circumferential S1 side portion of the weight 122, and a second tangent line LT2 that passes through the center 15C of the output shaft 15 and is in contact with the second circumferential S2 side portion of the weight 122.

[0066] As shown in Figure 11, when the weight 122 is located at the outer diameter side position PO, the straight line LS passing through the center 122C of the weight 122 and the center 15C of the output shaft 15, when viewed in the axial direction of the output shaft 15, passes through the pressure-side slipper cam surface 90S. During the process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, the straight line LS passes through the pressure-side slipper cam surface 90S. The straight line LS may pass through the pressure-side slipper cam surface 90S throughout the entire process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO. In this embodiment, the straight line LS passes through the pressure-side slipper cam surface 90S throughout the entire process of a single weight 122 moving from the inner diameter side position PI to the outer diameter side position PO. Throughout the entire process of the weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, the first circumferential edge 90SS1 of the pressure-side slipper cam surface 90S is located on the first circumferential direction S1 side of the straight line LS, and the second circumferential edge 90SS2 of the pressure-side slipper cam surface 90S is located on the second circumferential direction S2 side of the straight line LS, and the pressure-side slipper cam surface 90S is provided such that the straight line LS passes through the pressure-side slipper cam surface 90S. As a result, when the clutch center 40 rotates relative to the pressure plate 70 (for example, when the rotational speed of the clutch center 40 exceeds the rotational speed of the pressure plate 70), the weight 122 is efficiently pressed via the pressure-side slipper cam surface 90S in the direction from the outer diameter position PO to the inner diameter position PI, thereby separating the drive-side clutch plate 20 and the driven-side clutch plate 22 at an early stage and reducing the transmission of rotational driving force from the input shaft to the output shaft 15 at an early stage. When the weight 122 is positioned at the outer diameter side position PO, when viewed in the axial direction of the output shaft 15, at least a portion of the pressure-side slipper cam surface 90S is located in the region enclosed by a first tangent line LT1 that passes through the center 15C of the output shaft 15 and is in contact with the first circumferential S1 side portion of the weight 122, and a second tangent line LT2 that passes through the center 15C of the output shaft 15 and is in contact with the second circumferential S2 side portion of the weight 122.During the process in which the weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, at least a portion of the pressure-side slipper cam surface 90S is located in the region enclosed by the first tangent LT1 and the second tangent LT2. Throughout the entire process in which the weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, at least a portion of the pressure-side slipper cam surface 90S may be located in the region enclosed by the first tangent LT1 and the second tangent LT2. In this embodiment, throughout the entire process of a weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, at least a portion (e.g., all) of the region enclosed by the first slipper-side straight line LS1 passing through the center 15C of the output shaft 15 and the first circumferential edge 90SS1 of the pressure-side slipper cam surface 90S in the circumferential direction S1, and the second slipper-side straight line LS2 passing through the center 15C of the output shaft 15 and the second circumferential edge 90SS2 of the pressure-side slipper cam surface 90S in the circumferential direction S2, is configured to overlap with the region enclosed by the first tangent line LT1 and the second tangent line LT2. As a result, when the clutch center 40 rotates relative to the pressure plate 70 (for example, when the rotational speed of the clutch center 40 exceeds the rotational speed of the pressure plate 70), the weight 122 is efficiently pressed in the direction from the outer diameter position PO to the inner diameter position PI via the pressure-side slipper cam surface 90S, thereby separating the drive-side clutch plate 20 and the driven-side clutch plate 22 at an early stage and reducing the transmission of rotational driving force from the input shaft to the output shaft 15 at an early stage. In Figures 8 to 11, one linear LS (i.e., one weight 122) is used as an example, but in this embodiment, there are 16 linear LSs (i.e., 16 weights 122), and several of them (for example, 2 or 3) may be the same as the configuration disclosed herein.

[0067] In the centrifugal clutch mechanism 120 with the above configuration, when no centrifugal force is applied to the weight 122, the weight 122 is held at the inner diameter side position PI (see Figure 1) by the release spring 102, 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 122, the weight 122 moves from the inner diameter side position PI to the outer diameter side position PO (see Figure 7). As a result, the interlocking member 130, the thrust bearing 105 and the contact plate 107 are pressed by the weight 122 and move in the first direction D1. When the pressing force from the weight 122 on the interlocking member 130, etc. 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.

[0068] As described above, according to the clutch device 10 of this embodiment, throughout the entire process in which one weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, the straight line LS passing through the center 122C of one weight 122 and the center 15C of the output shaft 15, when viewed in the axial direction of the output shaft 15, passes through the pressure side slipper cam surface 90S. According to the above embodiment, when the clutch center 40 rotates relative to the pressure plate 70, one weight 122 is efficiently pressed in the direction from the outer diameter side position PO to the inner diameter side position PI via the pressure side slipper cam surface 90S. As a result, the drive side clutch plate 20 and the driven side clutch plate 22 can be separated early, and the transmission of rotational driving force from the input shaft to the output shaft 15 can be reduced early.

[0069] In the clutch device 10 of this embodiment, throughout the entire process of one weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, at least a portion of the pressure-side slipper cam surface 90S is located in the region enclosed by the first tangent LT1 and the second tangent LT2 when viewed in the axial direction of the output shaft 15. In this embodiment, when the clutch center 40 rotates relative to the pressure plate 70, one weight 122 is efficiently pressed in the direction from the outer diameter side position PO to the inner diameter side position PI via the pressure-side slipper cam surface 90S. This allows the drive-side clutch plate 20 and the driven-side clutch plate 22 to be separated early, thereby reducing the transmission of rotational driving force from the input shaft to the output shaft 15 at an early stage.

[0070] In the clutch device 10 of this embodiment, the pressure-side slipper cam surface 90S is provided such that, when viewed in the axial direction, the straight line LS passes through the pressure-side slipper cam surface 90S throughout the entire process in which one weight 122 moves from the inner diameter side position PI to the outer diameter side position PO. In this embodiment, when the clutch center 40 rotates relative to the pressure plate 70, one weight 122 is efficiently pressed in the direction from the outer diameter side position PO to the inner diameter side position PI via the pressure-side slipper cam surface 90S. This makes it possible to separate the drive-side clutch plate 20 and the driven-side clutch plate 22 early and reduce the transmission of rotational driving force from the input shaft to the output shaft 15 early.

[0071] In the clutch device 10 of this embodiment, throughout the entire process of one weight 122 moving from the inner diameter side position PI to the outer diameter side position PO, when viewed in the axial direction of the output shaft 15, at least a portion of the region enclosed by the first slipper side straight line LS1 and the second slipper side straight line LS2 overlaps with the region enclosed by the first tangent line LT1 and the second tangent line LT2 in the circumferential direction S. According to the above embodiment, when the clutch center 40 rotates relative to the pressure plate 70, one weight 122 is efficiently pressed in the direction from the outer diameter side position PO to the inner diameter side position PI via the pressure side slipper cam surface 90S. This makes it possible to separate the drive side clutch plate 20 and the driven side clutch plate 22 early and reduce the transmission of rotational driving force from the input shaft to the output shaft 15 early.

[0072] In the clutch device 10 of this embodiment, the pressure-side assist cam surface 90A is provided such that, when viewed in the axial direction, the straight line LS passes through the pressure-side assist cam surface 90A throughout the entire process in which one weight 122 moves from the inner diameter side position PI to the outer diameter side position PO. In this embodiment, the pressure-side assist cam surface 90A is pressed more reliably by the weight 122 towards the center-side assist cam surface 60A, so that the rotational driving force of the input shaft can be transmitted to the output shaft 15 more reliably via the pressure-side assist cam surface 90A and the center-side assist cam surface 60A.

[0073] In the clutch device 10 of this embodiment, throughout the entire process in which one weight 122 moves from the inner diameter side position PI to the outer diameter side position PO, when viewed in the axial direction of the output shaft 15, at least a portion of the region enclosed by the first assist side straight line LA1 and the second assist side straight line LA2 overlaps with the region enclosed by the first tangent line LT1 and the second tangent line LT2 with respect to the circumferential direction S. In this embodiment, the pressure side assist cam surface 90A is pressed more reliably towards the center side assist cam surface 60A by the weight 122, so that the rotational driving force of the input shaft can be transmitted to the output shaft 15 more reliably via the pressure side assist cam surface 90A and the center side assist cam surface 60A.

[0074] 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.

[0075] In the embodiment described above, the weight 122 was configured to move as a whole between a first position (inner diameter side position PI) and a second position (outer diameter side position PO), but is not limited thereto. For example, a part of the weight 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 to move from the first position to the second position includes cases where the entire weight is movable as described above, and cases where only a part of the weight is movable (swings).

[0076] 10 Clutch device 15 Output shaft (output member) 20 Drive-side clutch plate 22 Driven-side clutch plate 25 Clutch spring 30 Clutch housing 40 Clutch center 41 First clutch center 51 Second clutch center 60 Center-side cam section 60A Center-side assist cam surface 60S Center-side slipper cam surface 70 Pressure plate 90 Pressure-side cam section 90A Pressure-side assist cam surface 90S Pressure-side slipper cam surface 120 Centrifugal clutch mechanism 122 Weight 124 Housing 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 and move away from the clutch center, which holds at least one 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 weights that can move 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 clutch center comprises a center-side cam portion having a center-side slipper cam surface that, when rotated relative to the pressure plate, separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate; the pressure plate comprises a pressure-side cam portion having a pressure-side slipper cam surface that, when rotated relative to the clutch center, is configured to be in contact with the center-side slipper cam surface and separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate; the clutch device is configured such that the drive-side clutch plate and the driven-side clutch plate are pressed together as the weight moves from the first position to the second position; and throughout the entire process of one of the weights moving from the first position to the second position, the straight line passing between the center of one of the weights and the center of the output member, when viewed in the axial direction of the output member, passes through the pressure-side slipper cam surface.

2. The clutch device according to claim 1, wherein, when the weight is in the first position, at least a portion of the weight overlaps with the pressure-side slipper cam surface when viewed in the axial direction of the output member.

3. 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 and move away from the clutch center, which holds at least one 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 weights that can move from an inner diameter side position that can release the contact force between the drive-side clutch plates and the driven-side clutch plates 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 an outer diameter side position that brings the drive-side clutch plates and the driven-side clutch plates into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, The clutch center is provided with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate when the clutch center rotates relative to the pressure plate, the pressure plate is provided with a pressure-side cam portion having a pressure-side slipper cam surface that is configured to be in contact with the center-side slipper cam surface when the clutch center rotates relative to the clutch center and that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate, the weight is configured to move from the inner diameter side position to the outer diameter side position so that the drive-side clutch plate and the driven-side clutch plate are pressed together, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction.A clutch device wherein, throughout the entire process in which one of the weights moves from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the pressure-side slipper cam surface is located in a region enclosed by a first tangent line passing through the center of the output member and touching the first circumferential portion of one of the weights, and a second tangent line passing through the center of the output member and touching the second circumferential portion of one of the weights.

4. 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 and move away from the clutch center, which holds at least one 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 weights that can move 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 clutch center is provided with a center-side cam portion having a center-side slipper cam surface that, when rotated relative to the pressure plate, separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate; the pressure plate is provided with a pressure-side cam portion having a pressure-side slipper cam surface that, when rotated relative to the clutch center, is configured to be in contact with the center-side slipper cam surface and separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate; the weight is configured to move from the first position to the second position so that the drive-side clutch plate and the driven-side clutch plate are pressed together; and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction.A clutch device in which, throughout the entire process of one of the weights moving from the first position to the second position, when viewed in the axial direction of the output member, the first circumferential edge of the pressure-side slipper cam surface is located on the first circumferential side of a straight line passing through the center of one of the weights and the center of the output member, and the second circumferential edge of the pressure-side slipper cam surface is located on the second circumferential side of the straight line, and the pressure-side slipper cam surface is provided such that the straight line passes through the pressure-side slipper cam surface.

5. 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 and move away from the clutch center, which holds at least one 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 weights that are movable from an inner diameter side position that can release the contact force between the drive-side clutch plates and the driven-side clutch plates 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 an outer diameter side position that brings the drive-side clutch plates and the driven-side clutch plates into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, The clutch center is provided with a center-side cam portion having a center-side slipper cam surface that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate when the clutch center rotates relative to the pressure plate, the pressure plate is provided with a pressure-side cam portion having a pressure-side slipper cam surface that is configured to be in contact with the center-side slipper cam surface when the clutch center rotates relative to the clutch center and that separates the pressure plate from the clutch center in order to reduce the pressing force between the drive-side clutch plate and the driven-side clutch plate, the weight is configured to move from the inner diameter side position to the outer diameter side position so that the drive-side clutch plate and the driven-side clutch plate are pressed together, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion is defined as the first circumferential direction, and the direction from the other pressure-side cam portion toward the one pressure-side cam portion is defined as the second circumferential direction.A clutch device configured such that, throughout the entire process of one of the weights moving from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the region enclosed by a first slipper-side straight line passing through the center of the output member and the first circumferential edge of the pressure-side slipper cam surface, and a second slipper-side straight line passing through the center of the output member and the second circumferential edge of the pressure-side slipper cam surface, overlaps with a region enclosed by a first tangent line passing through the center of the output member and touching the first circumferential portion of one of the weights, and a second tangent line passing through the center of the output member and touching the second circumferential portion of one of the weights.

6. 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 and move away from the clutch center, which holds at least one 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 weights that can move 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 clutch center comprises a center-side cam portion having a center-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate when the clutch center rotates relative to the pressure plate, the pressure plate comprises a pressure-side cam portion having a pressure-side assist cam surface that is configured to be in contact with the center-side assist cam surface when the pressure plate rotates relative to the clutch center and generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate, the weight is configured to move from the first position to the second position so that the drive-side clutch plate and the driven-side clutch plate are pressed together, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion toward the other pressure-side cam portion toward the first pressure-side cam portion toward the second pressure-side cam portion toward the firstA clutch device in which, throughout the entire process of one of the weights moving from the first position to the second position, when viewed in the axial direction of the output member, the first circumferential edge of the pressure-side assist cam surface is located on the first circumferential side of a straight line passing through the center of one of the weights and the center of the output member, and the second circumferential edge of the pressure-side assist cam surface is located on the second circumferential side of the straight line, and the pressure-side assist cam surface is provided such that the straight line passes through the pressure-side assist cam surface.

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 and move away from the clutch center, which holds at least one of a plurality of driven-side clutch plates arranged alternately with the drive-side clutch plates, and which can press the drive-side clutch plate and the driven-side clutch plate; and a centrifugal clutch mechanism having a plurality of weights that are movable from an inner diameter side position that can release the contact force between the drive-side clutch plate and the driven-side clutch plate 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 an outer diameter side position that brings the drive-side clutch plate and the driven-side clutch plate into contact, thereby enabling the transmission of the rotational driving force of the input member to the output member, The clutch center comprises a center-side cam portion having a center-side assist cam surface that generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate when the clutch center rotates relative to the pressure plate, the pressure plate comprises a pressure-side cam portion having a pressure-side assist cam surface that is configured to be in contact with the center-side assist cam surface when the pressure plate rotates relative to the clutch center and generates a force in the direction toward the clutch center from the pressure plate in order to increase the pressing force between the drive-side clutch plate and the driven-side clutch plate, the weight is configured to move from the inner diameter side position to the outer diameter side position so that the drive-side clutch plate and the driven-side clutch plate are pressed against each other, and the direction from one of the pressure-side cam portions toward the other pressure-side cam portion toward the other pressure-side cam portion toward the first circumferential direction,A clutch device configured such that, throughout the entire process in which one of the weights moves from the inner diameter side position to the outer diameter side position, when viewed in the axial direction of the output member, at least a portion of the region enclosed by a first assist-side straight line passing through the center of the output member and the first circumferential edge of the pressure-side assist cam surface, and a second assist-side straight line passing through the center of the output member and the second circumferential edge of the pressure-side assist cam surface, overlaps with the region enclosed by a first tangent line passing through the center of the output member and touching the first circumferential portion of one of the weights, and a second tangent line passing through the center of the output member and touching the second circumferential portion of one of the weights.

Images