Clutch device

Abstract

To provide a clutch device equipped with a centrifugal clutch mechanism capable of sufficiently pressing a driving side clutch plate and a driven side clutch plate into contact with each other. [Solution] The clutch device 10 comprises a clutch center 40, a pressure plate 70, a support plate 150, a bolt 28 connecting the clutch center 40 and the support plate 150, and a centrifugal clutch mechanism 120 having a weight member 122, the centrifugal clutch mechanism 120 being positioned on the opposite side of the pressure plate 70 from the driving side clutch plate 20 and the driven side clutch plate 22 in direction D, the weight member 122 being positioned radially outward from the axis 28L of the bolt 28, and the centrifugal clutch mechanism 120 presses the driving side clutch plate 20 and the driven side clutch plate 22 together by movement of the weight member 122.

Description

[Technical Field]

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

[0002] Straddle-type vehicles such as motorcycles are equipped with a clutch device that can transmit and interrupt the rotational driving force of a driving source such as an engine to a driving wheel. For example, Patent Document 1 discloses a clutch device that includes a support plate, a pressure plate, and a clutch center. The clutch device of Patent Document 1 further includes a cam mechanism that increases the pressure contact force of the clutch portion (e.g., a driving-side clutch plate and a driven-side clutch plate), and a slipper cam mechanism that reduces the pressure contact force of the clutch portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-89016 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, conventionally, there have been clutch devices equipped with a centrifugal clutch mechanism that increases the pressure contact force between the drive-side clutch plates and the driven-side clutch plates when the weight member moves from a first position to a second position due to centrifugal force caused by rotation of the clutch housing. If such a centrifugal clutch mechanism is to be provided in the clutch device disclosed in Patent Document 1, there is a risk that the drive-side clutch plates and the driven-side clutch plates may not be sufficiently pressure contacted depending on the position at which the centrifugal clutch mechanism is disposed.

[0005] The present invention has been made in consideration of the above points, and its object is to provide a clutch device equipped with a centrifugal clutch mechanism that can sufficiently press the drive side clutch plate and the driven side clutch plate together. [Means for solving the problem]

[0006] The clutch device according to the present invention is a clutch device that transmits or interrupts the rotational drive force of an input member to an output member, and includes a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by the rotational drive of the input member, a first rotor that is connected to the output member and has a first cam surface, a second cam surface that is configured to be able to come into contact with the first cam surface, and a third cam surface, and is provided so as to be movable in the axial direction of the output member and rotatable relative to the first rotor, and a plurality of driven-side clutch plates that are arranged alternately with the drive-side clutch plates. a second rotor that holds at least one of the plates; a third rotor that is fixed to the first rotor so as to be located on the opposite side of the first rotor with the second rotor in the axial direction and has a fourth cam surface configured to be able to come into contact with the third cam surface; at least one connecting member that connects the first rotor and the third rotor; and a first cam mechanism that is formed by the first cam surface and the second cam surface and is configured to move the second rotor from one side to the other in the axial direction when relative rotation occurs between the first rotor and the second rotor. a second cam mechanism that is constituted by the third cam surface and the fourth cam surface and that is configured to move the second rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor; and a second cam mechanism that is configured to release the pressing force between the driving side clutch plate and the driven side clutch plate as the centrifugal force increases with rotation of the clutch housing, thereby pressing the driving side clutch plate and the driven side clutch plate together to transmit the rotational driving force of the input member to the output member from a first position where the pressing force between the driving side clutch plate and the driven side clutch plate can be released and the rotational driving force of the input member can be cut off from the first position where the pressing force between the driving side clutch plate and the driven side clutch plate can be cut off and the rotational driving force of the input member can be and a centrifugal clutch mechanism having a plurality of weight members that can be moved to a second position so that the force can be transmitted to the member, wherein the centrifugal clutch mechanism is located on the opposite side of the driving side clutch plate and the driven side clutch plate, sandwiching the second rotating body in the axial direction, and the weight members are located radially outward from the axis of the connecting member that extends in the axial direction, and the centrifugal clutch mechanism is configured so that the weight members move from the first position to the second position to press the driving side clutch plate and the driven side clutch plate together.

[0007] In the clutch device according to the present invention, the centrifugal clutch mechanism is located on the opposite side of the second rotor from the drive clutch plates and the driven clutch plates in the axial direction, and the weight member is located radially outward from the axis of the connecting member extending in the axial direction. According to the above aspect, the weight member can sufficiently press the drive clutch plates and the driven clutch plates together. Furthermore, because the weight member is located in the space radially outward from the connecting member, the size of the clutch device can be reduced.

[0008] Another clutch device according to the present invention is a clutch device that transmits or interrupts the rotational drive force of an input member to an output member, and includes: a first rotor that is housed in a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by the rotational drive of the input member, and is connected to the output member, and has a first cam surface; a second rotor that has a first cam surface; a second cam surface and a third cam surface that are configured to be able to come into contact with the first cam surface; a third rotor that is fixed to the first rotor so as to be located on the opposite side of the first rotor with respect to the axial direction of the output member and to be rotatable relative to the first rotor; a fourth cam surface that is configured to be able to come into contact with the third cam surface; at least one connecting member that connects the first rotor and the third rotor; and a connecting member that is configured by the first cam surface and the second cam surface and that moves the second rotor from one side in the axial direction to the other when relative rotation occurs between the first rotor and the second rotor. a second cam mechanism configured by the third cam surface and the fourth cam surface and configured to move the second rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor; and a second cam mechanism configured to compress the driving side clutch plates and the driven side clutch plates from a first position where the pressing force between the driving side clutch plates and the driven side clutch plates can be released and the transmission of the rotational driving force of the input member to the output member can be interrupted as the centrifugal force increases with rotation of the clutch housing. and a centrifugal clutch mechanism having a plurality of weight members that can be moved to a second position where the driving side clutch plate and the driven side clutch plate are brought into contact with each other so that the rotational driving force of the input member can be transmitted to the output member, wherein at least a portion of the centrifugal clutch mechanism is disposed between the first rotating body and the second rotating body in the axial direction and overlaps with the connecting member when viewed from the radial direction, and the centrifugal clutch mechanism is configured such that the weight members move from the first position to the second position to press the driving side clutch plate and the driven side clutch plate together.

[0009] In another clutch device according to the present invention, at least a portion of the centrifugal clutch mechanism is disposed axially between the first rotor and the second rotor and overlaps with the connecting member when viewed radially. According to the above aspect, the centrifugal clutch mechanism can sufficiently press the driving-side clutch plate and the driven-side clutch plate into contact with each other.

[0010] Another clutch device according to the present invention is a clutch device that transmits or interrupts the rotational drive force of an input member to an output member, and includes: a first rotor 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 holds at least one of a plurality of driven-side clutch plates that are arranged alternately with the drive-side clutch plates, the second rotor having a first cam surface, a second cam surface configured to be able to come into contact with the first cam surface, and a third cam surface, and is connected to the output member; a third rotor fixed to the first rotor so as to be located on the opposite side of the first rotor with the second rotor sandwiched between them in the axial direction of the output member, and that has a fourth cam surface configured to be able to come into contact with the third cam surface; at least one connecting member that connects the first rotor and the third rotor; a first cam mechanism that is formed by the first cam surface and the second cam surface, and that is configured to move the first rotor from one side in the axial direction to the other when relative rotation occurs between the first rotor and the second rotor; a second cam mechanism formed by a cam surface and the fourth cam surface, and configured to move the first rotor from one side in the axial direction to the other side when relative rotation occurs between the second rotor and the third rotor; and a centrifugal clutch mechanism having a plurality of weight members that are movable from a first position at which the pressing force between the drive side clutch plate and the driven side clutch plate is released and the rotational driving force of the input member is prevented from being transmitted to the output member as the centrifugal force increases with rotation of the clutch housing, to a second position at which the drive side clutch plate and the driven side clutch plate are pressed together, allowing the rotational driving force of the input member to be transmitted to the output member, wherein at least a portion of the centrifugal clutch mechanism is disposed between the first rotor and the second rotor in the axial direction and overlaps with the connecting member when viewed from the radial direction, and the centrifugal clutch mechanism is configured to press the drive side clutch plate and the driven side clutch plate together when the weight members move from the first position to the second position.

[0011] In another clutch device according to the present invention, at least a portion of the centrifugal clutch mechanism is disposed axially between the first rotor and the second rotor and overlaps with the connecting member when viewed radially. According to the above aspect, the centrifugal clutch mechanism can sufficiently press the driving-side clutch plate and the driven-side clutch plate into contact with each other.

[0012] Another clutch device according to the present invention is a clutch device that transmits or interrupts the rotational drive force of an input member to an output member, and includes a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by the rotational drive of the input member, a first rotor that is connected to the output member and has a first cam surface, a second cam surface that is configured to be able to come into contact with the first cam surface, and a third cam surface, and is provided so as to be movable in the axial direction of the output member and rotatable relative to the first rotor, and a plurality of driven-side clutch plates that are arranged alternately with the drive-side clutch plates. a second rotor that holds at least one of the clutch plates; a third rotor that is fixed to the first rotor so as to be located on the opposite side of the first rotor with the second rotor sandwiched in the axial direction and has a fourth cam surface configured to be able to come into contact with the third cam surface; at least one connecting member that connects the first rotor and the third rotor; and a first clutch mechanism that is configured by the first cam surface and the second cam surface and that moves the second rotor from one side to the other in the axial direction when relative rotation occurs between the first rotor and the second rotor. a second cam mechanism constituted by the third cam surface and the fourth cam surface and configured to move the second rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor; and a second cam mechanism configured to press the driving side clutch plate and the driven side clutch plate together to rotate the input member from a first position where a pressing force between the driving side clutch plate and the driven side clutch plate can be released and transmission of the rotational driving force of the input member to the output member can be interrupted as a centrifugal force increases with rotation of the clutch housing. and a centrifugal clutch mechanism having a plurality of weight members that are movable to a second position that enables force to be transmitted to the output member, and a pressure member that moves in the axial direction as the weight members move from the first position to the second position, thereby pressing the drive side clutch plate and the driven side clutch plate together, wherein the centrifugal clutch mechanism is located on the opposite side of the drive side clutch plate and the driven side clutch plate in the axial direction, with the first rotating body in between, and the pressure member is located radially outward of the axis of the connecting member that extends in the axial direction.

[0013] In another clutch device according to the present invention, the centrifugal clutch mechanism is located axially opposite the driving clutch plates and the driven clutch plates across the first rotor, and the pressing member is located radially outward from the axis of the connecting member extending axially. According to this aspect, the pressing member can sufficiently press the driving clutch plates and the driven clutch plates together. Furthermore, because the pressing member is located in the space radially outward from the connecting member, the size of the clutch device can be reduced.

[0014] Another clutch device according to the present invention is a clutch device that transmits or interrupts the rotational drive force of an input member to an output member, and includes: a first rotor 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 holds at least one of a plurality of driven-side clutch plates that are arranged alternately with the drive-side clutch plates, and that has a first cam surface, a second cam surface configured to be able to come into contact with the first cam surface, and a third cam surface, and that is connected to the output member; a third rotor that is fixed to the first rotor so as to be located on the opposite side of the first rotor with the second rotor sandwiched between them in the axial direction of the output member, and that has a fourth cam surface configured to be able to come into contact with the third cam surface; at least one connecting member that connects the first rotor and the third rotor; a first cam mechanism that is constituted by the first cam surface and the second cam surface, and that is configured to move the first rotor from one side in the axial direction to the other when relative rotation occurs between the first rotor and the second rotor; a second cam mechanism configured by a cam surface and configured to move the first rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor; and a second cam mechanism configured by a cam surface and configured to move the first rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor, and a second cam mechanism configured by a cam surface and configured to move the first rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor, and a second cam mechanism configured by a cam surface and configured to move the first rotor from the other side to the one side in the axial direction when relative rotation occurs between the second rotor and the third rotor, and a and a centrifugal clutch mechanism having a plurality of weight members movable to a second position that makes the drive side clutch plate and the driven side clutch plate press together when the weight members move from the first position to the second position, wherein the centrifugal clutch mechanism is located on the opposite side of the drive side clutch plate and the driven side clutch plate in the axial direction across the first rotating body, and the pressure member is located radially outward of the axis of the connecting member extending in the axial direction.

[0015] In another clutch device according to the present invention, the centrifugal clutch mechanism is located axially opposite the driving clutch plates and the driven clutch plates across the first rotor, and the pressing member is located radially outward from the axis of the connecting member extending axially. According to this aspect, the pressing member can sufficiently press the driving clutch plates and the driven clutch plates together. Furthermore, because the pressing member is located in the space radially outward from the connecting member, the size of the clutch device can be reduced. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a clutch device equipped with a centrifugal clutch mechanism that can sufficiently press the drive-side clutch plates and the driven-side clutch plates into contact with each other. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing a part of a clutch device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the clutch center according to the first embodiment. [Figure 3] FIG. 3 is a perspective view showing a pressure plate according to the first embodiment. [Figure 4] FIG. 4 is a perspective view showing the pressure plate according to the first embodiment. [Figure 5] FIG. 5 is a perspective view showing the support plate according to the first embodiment. [Figure 6A] FIG. 6A is a schematic diagram illustrating the operation of the first cam mechanism according to the first embodiment. [Figure 6B] FIG. 6B is a schematic diagram illustrating the operation of the second cam mechanism according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which the weight member is located at the second position. [Figure 8] FIG. 8 is a perspective view of the centrifugal clutch mechanism according to the first embodiment. [Figure 9]FIG. 9 is a cross-sectional view showing a part of a clutch device according to the second embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a state in which the weight member is located at the second position. [Figure 11] FIG. 11 is a cross-sectional view showing a part of a clutch device according to a third embodiment. [Figure 12A] FIG. 12A is a schematic diagram illustrating the operation of the first cam mechanism according to the third embodiment. [Figure 12B] FIG. 12B is a schematic diagram illustrating the action of the second cam mechanism according to the third embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing a part of a clutch device according to a fourth embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing a state in which the weight member is located at the second position. [Figure 15] FIG. 15 is a cross-sectional view showing a part of a clutch device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of a clutch device according to the present invention will be described with reference to the drawings. It should be noted that the embodiment described here is not intended to limit the present invention in any particular way. Furthermore, the same reference numerals are used to designate members and parts that perform the same functions, and redundant descriptions will be omitted or simplified as appropriate.

[0019] First Embodiment FIG. 1 is a cross-sectional view showing a portion of a clutch device 10 according to a first embodiment. The clutch device 10 is provided on a vehicle such as a motorcycle. The clutch device 10 is a device that transmits or cuts off the rotational driving force of an input member (crankshaft) of a driving source (e.g., an engine) of the motorcycle to an output shaft 15. The clutch device 10 is a device that transmits or cuts off the rotational driving force of the input member to a driving wheel (rear wheel) via the output shaft 15. The clutch device 10 is disposed between the driving source and a transmission. The output shaft 15 is an example of an output member.

[0020] 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 referred to as direction D, the direction in which the pressure plate 70 approaches the clutch center 40 is referred to as first direction D1, and the direction in which the pressure plate 70 moves away from the clutch center 40 is referred to as second direction D2. The circumferential direction of the clutch center 40, the pressure plate 70, and the support plate 150 is defined as the circumferential direction S, and the direction from one pressure-side cam portion 90 to the other pressure-side cam portion 90 with respect to the circumferential direction S (the direction from one center-side cam portion 60 to the other center-side cam portion 60; the direction from one support-side cam portion 160 to the other support-side cam portion 160) is defined as the first circumferential direction S1 (see FIG. 3), and the direction from the other pressure-side cam portion 90 to one pressure-side cam portion 90 (the direction from the other center-side cam portion 60 to one center-side cam portion 60; the direction from the other support-side cam portion 160 to one support-side cam portion 160) is defined as the second circumferential direction S2 (see FIG. 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 directions of the pressure plate 70 and the support plate 150 are the same as the direction D. Furthermore, the pressure plate 70, the clutch center 40, and the support plate 150 rotate in a first circumferential direction S1 (i.e., the direction from the pressure-side slipper cam surface 90S of one pressure-side cam portion 90 toward the pressure-side assist cam surface 90A). However, the above direction is merely defined for the convenience of explanation, and does not limit the installation mode of the clutch device 10 or the present invention in any way.

[0021] As shown in Fig. 1, the clutch device 10 includes an output shaft 15, a driving-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 40, a pressure plate 70, a centrifugal clutch mechanism 120, and a support plate 150. The clutch center 40 is an example of a first rotating body. The pressure plate 70 is an example of a second rotating body. The support plate 150 is an example of a third rotating body.

[0022] As shown in Fig. 1, the output shaft 15 is a hollow shaft body. One end of the output shaft 15 rotatably supports an input gear 35 and a clutch housing 30 (described later) via a needle bearing 15A. The output shaft 15 fixedly supports a 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 motorcycle.

[0023] As shown in FIG. 1 , the output shaft 15 includes a hollow portion 15H, which houses a push rod 16A and a push member 16B located adjacent to the push rod 16A. The hollow portion 15H functions as a passageway for clutch oil. The clutch oil flows through the output shaft 15, i.e., the hollow portion 15H. The push rod 16A and the push member 16B are slidably disposed within the hollow portion 15H of the output shaft 15. One end (the end on the left side in the figure) of the push rod 16A is connected to a clutch operating lever (not shown) of the motorcycle. When the clutch operating lever is operated, the push rod 16A slides within the hollow portion 15H and presses the push member 16B in the second direction D2. A portion of the push member 16B protrudes outward from the output shaft 15 (in this case, in the second direction D2) and is connected to a release bearing 18 provided on the pressure 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. The push rod 16A may be configured to slide electrically using a servo motor or the like.

[0024] The clutch housing 30 is made of an aluminum alloy. The clutch housing 30 is formed in a cylindrical shape with a bottom. As shown in FIG. 1 , the clutch housing 30 has a bottom wall 31 formed in a substantially circular shape and a side wall 33 extending in a direction D from an edge of the bottom wall 31. The clutch housing 30 holds a plurality of driving-side clutch plates 20.

[0025] As shown in Fig. 1, an input gear 35 is provided on the bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by rivets 35B via a torque damper (not shown). The input gear 35 meshes with a drive gear (not shown) that rotates when an input member of the engine is rotated. The input gear 35 rotates integrally with the clutch housing 30, independently of the output shaft 15.

[0026] The driving side clutch plate 20 is rotationally driven by the rotational drive of the input member. As shown in FIG. 1, the driving side clutch plate 20 is held on the inner circumferential surface of the side wall 33 of the clutch housing 30. The driving side clutch plate 20 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. The driving side clutch plate 20 is provided so as to be displaceable along the axial direction of the clutch housing 30 (i.e., direction D). The driving side clutch plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0027] The driving side clutch plate 20 is a member that is pressed against the driven side clutch plate 22. The driving side clutch plate 20 is formed in an annular shape. The driving side clutch plate 20 is formed by aluminum die-casting. Friction material (not shown) made of multiple pieces of paper is attached to the front and back surfaces of the driving side clutch plate 20. Grooves several hundred microns deep are formed between the friction materials to hold clutch oil.

[0028] As shown in FIG. 1 , the clutch center 40 is accommodated in the clutch housing 30. The clutch center 40 is disposed concentrically with the clutch housing 30. The clutch center 40 has a cylindrical main body 42 and a center-side flange 68 that extends radially outward from the outer circumferential edge of the main body 42. The main body 42 has a portion that protrudes beyond the center-side flange 68 in the second direction D2. The clutch center 40 holds a portion of the driven-side clutch plate 22. The clutch center 40 is driven to rotate together with the output shaft 15.

[0029] 2, the main body 42 includes an annular base portion 43, a center-side outer peripheral wall 45 extending from the base portion 43 in the second direction D2, an output shaft holding portion 50 provided in the center of the base portion 43, a plurality of center-side cam portions 60 formed on the base portion 43, and a center-side fitting portion 58. The center-side cam portion 60 is formed to protrude in the second direction D2 beyond a center-side flange 68. The center-side cam portion 60 is located radially outward of the output shaft holding portion 50.

[0030] As shown in FIG. 2, the center-side flange 68 extends radially outward from the outer peripheral edge of the main body 42. The center-side flange 68 is located radially outward of the center-side cam portion 60. The center-side flange 68, together with a pressure-side flange 98 (see FIG. 1) of the pressure plate 70 (described later), sandwiches the drive-side clutch plates 20 and the driven-side clutch plates 22. The center-side flange 68 has a pressing surface 68P that can press the drive-side clutch plates 20 and the driven-side clutch plates 22. The center-side flange 68 is a member that applies a pressing force to the drive-side clutch plates 20 and the driven-side clutch plates 22.

[0031] As shown in Fig. 2, the output shaft holding portion 50 is formed in a cylindrical shape. The output shaft holding portion 50 is formed with an insertion hole 51 into which the output shaft 15 (see Fig. 1) is inserted and spline-fitted. The insertion hole 51 is formed to penetrate the main body 42. An inner circumferential surface 50A of the output shaft holding portion 50 that forms the insertion hole 51 has a plurality of spline grooves formed along the axial direction. The output shaft 15 is connected to the output shaft holding portion 50.

[0032] As shown in FIG. 2 , the center-side outer peripheral wall 45 is disposed radially outward of the output shaft holding portion 50. The center-side outer peripheral wall 45 is formed in an annular shape when viewed from the axial direction of the output shaft 15. The center-side outer peripheral wall 45 extends in the axial direction of the output shaft 15 (i.e., direction D). A center-side spline fitting portion 46 is provided on an outer peripheral surface 45A of the center-side outer peripheral wall 45. The center-side spline fitting portion 46 has a plurality of center-side fitting teeth 47 extending in the axial direction of the clutch center 40 (i.e., direction D) along the outer peripheral surface 45A of the center-side outer peripheral wall 45, and a plurality of center-side spline grooves 48 formed between adjacent center-side fitting teeth 47 and extending in the axial direction of the clutch center 40. The center-side fitting teeth 47 hold a portion of the driven-side clutch plate 22. The plurality of center-side fitting teeth 47 are aligned in the circumferential direction S. The center-side fitting teeth 47 are formed at equal intervals in the circumferential direction S. The center-side fitting teeth 47 are formed to have the same shape. The center-side fitting teeth 47 protrude radially outward from the outer peripheral surface 45A of the center-side outer peripheral wall 45. The center-side spline grooves 48 are aligned in the circumferential direction S.

[0033] The driven-side clutch plates 22 are held by a center-side spline fitting portion 46 of the clutch center 40 and a pressure-side spline fitting portion 76 (see FIG. 3) of the pressure plate 70, which will be described later. A portion of the driven-side clutch plates 22 is held by spline fitting to center-side fitting teeth 47 and center-side spline grooves 48 of the clutch center 40. Another portion of the driven-side clutch plates 22 is held by spline fitting to pressure-side fitting teeth 77 (see FIG. 3) and pressure-side spline grooves 78 (see FIG. 3) of the pressure plate 70, which will be described later. The driven-side clutch plates 22 are provided so as to be displaceable along the axial direction of the clutch center 40. The driven-side clutch plates 22 are provided so as to be rotatable integrally with the clutch center 40.

[0034] The driven-side clutch plates 22 are members that are pressed against the driving-side clutch plates 20. The driven-side clutch plates 22 are formed in an annular shape. The driven-side clutch plates 22 are formed by punching out a thin plate material made of SPCC material into an annular shape. The friction material provided on the driving-side clutch plates 20 may be provided on the driven-side clutch plates 22 instead of the driving-side clutch plates 20, or may be provided on both the driving-side clutch plates 20 and the driven-side clutch plates 22.

[0035] As shown in FIG. 2 , the center-side cam portions 60 are 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. The center-side cam portions 60 are located radially outward of the output shaft holding portion 50. The center-side cam portions 60 have a center-side slipper cam surface 60S. The center-side slipper cam surface 60S is configured to move the pressure plate 70 away from the clutch center 40 to reduce the pressing force (pressure contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the clutch center 40 rotates relative to the pressure plate 70 during deceleration, for example. The center-side slipper cam surface 60S is an example of a first cam surface.

[0036] As shown in FIG. 1, an insertion hole 60H (see also FIG. 2) is formed in the center-side cam portion 60. The insertion hole 60H extends in the axial direction of the clutch center 40 (i.e., direction D). As shown in FIG. 2, in one center-side cam portion 60, the insertion hole 60H is located closer to the center-side slipper cam surface 60S in the second circumferential direction S2. A bolt 28 (see FIG. 1) that connects the clutch center 40 and the support plate 150 is inserted into the insertion hole 60H. The bolt 28 is an example of a connecting member.

[0037] As shown in Figure 2, the center-side fitting portion 58 is provided on the main body 42. The center-side fitting portion 58 is located radially outward of the center-side cam portion 60. The center-side fitting portion 58 is formed on the inner peripheral surface 45B of the center-side outer peripheral wall 45. The center-side fitting portion 58 is configured to be slidably fitted onto the pressure-side fitting portion 88 (see Figure 3).

[0038] As shown in FIG. 1 , the pressure plate 70 is accommodated in the clutch housing 30. The pressure plate 70 is located closer to the clutch center 40 in the second direction D2. The pressure plate 70 is movable (i.e., movable toward and away from) and rotatable relative to the clutch center 40 and the support plate 150 in the axial direction of the output shaft 15 (i.e., direction D). The pressure plate 70 is configured to be able to press the drive-side clutch plates 20 and the driven-side clutch plates 22. The pressure plate 70 is disposed concentrically with the clutch center 40 and the clutch housing 30. As shown in FIGS. 3 and 4 , the pressure plate 70 has a cylindrical main body 72 and a pressure-side flange 98 extending radially outward from the outer circumferential edge of the main body 72. The main body 72 has a portion that protrudes in the first direction D1 beyond the pressure-side flange 98. The pressure plate 70 holds at least a portion of the driven-side clutch plates 22.

[0039] As shown in Figures 3 and 4, the main body 72 comprises an annular base portion 73, a cylindrical portion 80 provided in the center of the base portion 73, a pressure side outer wall 75 located radially outside the base portion 73 and extending in direction D, a plurality of pressure side cam portions 90 provided on the base portion 73, a pressure side fitting portion 88, and a spring accommodating portion 89.

[0040] As shown in Figures 3 and 4, the pressure-side flange 98 extends radially outward from the outer peripheral edge of the main body 72. The pressure-side flange 98 is located radially outward of the pressure-side outer peripheral wall 75. The pressure-side flange 98, together with the center-side flange 68 of the clutch center 40, sandwiches the drive-side clutch plates 20 and the driven-side clutch plates 22. The pressure-side flange 98 has a pressing surface 98P that can press the drive-side clutch plates 20 and the driven-side clutch plates 22. The pressure-side flange 98 is a member that applies a pressing force to the drive-side clutch plates 20 and the driven-side clutch plates 22.

[0041] The cylindrical portion 80 is formed in a cylindrical shape. The cylindrical portion 80 accommodates the tip portion 15T (see FIG. 1) of the output shaft 15. The cylindrical portion 80 accommodates the release bearing 18 (see FIG. 1). The cylindrical portion 80 is a portion that receives a pressing force from the push member 16B. The cylindrical portion 80 is a portion that receives clutch oil that flows out from the tip portion 15T of the output shaft 15.

[0042] As shown in FIG. 3 , the pressure-side outer peripheral wall 75 is formed in an annular shape extending in the axial direction of the output shaft 15 (i.e., direction D). A pressure-side spline fitting portion 76 is provided on an outer peripheral surface 75A of the pressure-side outer peripheral wall 75. The pressure-side spline fitting portion 76 has a plurality of pressure-side fitting teeth 77 extending in the axial direction of the pressure plate 70 (i.e., direction D) along the outer peripheral surface 75A of the pressure-side outer peripheral wall 75, and a plurality of pressure-side spline grooves 78 formed between adjacent pressure-side fitting teeth 77 and extending in the axial direction of the pressure plate 70. The pressure-side fitting teeth 77 hold a portion of the driven-side clutch plate 22. The pressure-side fitting teeth 77 are aligned in the circumferential direction S. The pressure-side fitting teeth 77 are formed at equal intervals in the circumferential direction S. The pressure-side fitting teeth 77 are formed to have the same shape. The pressure-side fitting teeth 77 protrude radially outward from an outer peripheral surface 75A of the pressure-side outer peripheral wall 75. The pressure-side spline grooves 78 are aligned in the circumferential direction S.

[0043] As shown in FIG. 3, the pressure-side cam portions 90 are formed on the base portion 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. The pressure-side cam portions 90 are located radially outward of the cylindrical portion 80. The pressure-side cam portions 90 are located radially inward of the pressure-side outer peripheral wall 75. The pressure-side cam portions 90 have a pressure-side slipper cam surface 90S (see FIG. 3) and a pressure-side assist cam surface 90A (see FIG. 4). The pressure-side slipper cam surface 90S is configured to be able to come into contact with the center-side slipper cam surface 60S. The pressure-side slipper cam surface 90S is configured to move the pressure plate 70 away from the clutch center 40 in 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 during deceleration, etc. The pressure-side assist cam surface 90A is configured to be able to come into contact with a support-side assist cam surface 160A, which will be described later. The pressure-side assist cam surface 90A is configured to generate a force in a direction from the pressure plate 70 toward the clutch center 40 (i.e., the first direction D1) 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 support plate 150 (i.e., the clutch center 40) during acceleration, etc. In pressure-side cam portions 90 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 90M are arranged opposite each other in the circumferential direction S. In one pressure-side cam portion 90, the pressure-side slipper cam surface 90S is located closer to the second circumferential direction S2 than the pressure-side assist cam surface 90A. The pressure-side slipper cam surface 90S is an example of a second cam surface. The pressure-side assist cam surface 90A is an example of a third cam surface.

[0044] As shown in Figure 3, the pressure-side fitting portion 88 is located radially outward from the cylindrical portion 80. The pressure-side fitting portion 88 is located radially outward from the pressure-side cam portion 90. The pressure-side fitting portion 88 is formed on the outer peripheral surface of the base portion 73. The pressure-side fitting portion 88 is configured to be slidably fitted into the center-side fitting portion 58 (see Figure 2). A gap is formed between the pressure-side fitting portion 88 and the center-side fitting portion 58.

[0045] 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 portion 73. The pressure-side cam hole 73H penetrates the base portion 73 in direction D. The pressure-side cam hole 73H is located radially outward of the cylindrical portion 80. The pressure-side cam hole 73H is formed to penetrate between adjacent pressure-side cam portions 90. The pressure-side cam hole 73H is formed to penetrate between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of adjacent pressure-side cam portions 90.

[0046] As shown in FIG. 4, a bottomed, cylindrical spring accommodating portion 89 is formed in the pressure-side cam portion 90. The spring accommodating portion 89 is formed so as to be recessed from the second direction D2 to the first direction D1. The spring accommodating portion 89 is formed in a circular shape. In one pressure-side cam portion 90, the spring accommodating portion 89 is located closer to the pressure-side assist cam surface 90A in the second circumferential direction S2 and closer to the pressure-side slipper cam surface 90S in the first circumferential direction S1. The spring accommodating portion 89 accommodates a clutch spring (not shown). The clutch spring biases the pressure plate 70 toward the clutch center 40 (i.e., toward the first direction D1). The clutch spring is, for example, a coil spring formed by spirally winding spring steel.

[0047] As shown in FIG. 1, the support plate 150 is accommodated in the clutch housing 30. It is located on the opposite side of the clutch center 40 with the pressure plate 70 sandwiched between them in the axial direction of the output shaft 15 (i.e., direction D). Here, the support plate 150 is located closer to the pressure plate 70 in the second direction D2. The support plate 150 is fixed to the clutch center 40 by bolts 28. The support plate 150 is disposed concentrically with the pressure plate 70, the clutch center 40, and the clutch housing 30. As shown in FIG. 5, the support plate 150 includes a ring-shaped main body 152 and a plurality of support-side cam portions 160 extending from the main body 152 in the first direction D1.

[0048] 5, a through-hole 152H is formed in the center of the main body 152. The through-hole 152H passes through the main body 152 in direction D. The cylindrical portion 80 of the pressure plate 70 is inserted into the through-hole 152H.

[0049] As shown in FIG. 5, the support-side cam portions 160 are disposed at equal intervals in the circumferential direction S of the support plate 150. In this embodiment, the support plate 150 has three support-side cam portions 160, but the number of support-side cam portions 160 is not limited to three. The support-side cam portions 160 are located radially outward of the through-holes 152H. The support-side cam portions 160 have a support-side assist cam surface 160A. The support-side assist cam surface 160A is configured to be able to come into contact with the pressure-side assist cam surface 90A (see FIG. 4). The support-side assist cam surface 160A is configured to generate a force in a direction from the pressure plate 70 toward the clutch center 40 (i.e., the first direction D1) in order to increase the pressing force (pressing force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 70 rotates relative to the support plate 150 (i.e., the clutch center 40) during acceleration, for example. The support-side assist cam surface 160A is an example of a fourth cam surface.

[0050] As shown in FIG. 1, an insertion hole 160H (see also FIG. 5) is formed in the support side cam portion 160. The insertion hole 160H extends in the axial direction of the support plate 150 (i.e., direction D). As shown in FIG. 5, in one support side cam portion 160, the insertion hole 160H is located closer to the first circumferential direction S1 than the support side assist cam surface 160A. A bolt 28 that connects the clutch center 40 and the support plate 150 is inserted into the insertion hole 160H.

[0051] As shown in FIG. 6A, the clutch device 10 includes a first cam mechanism 101. The first cam mechanism 101 is composed of a center-side slipper cam surface 60S of the clutch center 40 and a pressure-side slipper cam surface 90S of the pressure plate 70. The first cam mechanism 101 is configured to move the pressure plate 70 in a second direction D2 when relative rotation occurs between the clutch center 40 and the pressure plate 70. For example, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30, causing back torque, a rotational force is applied to the clutch center 40 in a first circumferential direction S1. As a result, the center-side slipper cam surface 60S and the pressure-side slipper cam surface 90S act to move the pressure plate 70 in the second direction D2, thereby releasing the pressure contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22. This prevents engine and transmission malfunctions caused by back torque.

[0052] As shown in FIG. 6B , the clutch device 10 includes a second cam mechanism 102. The second cam mechanism 102 is configured by a pressure-side assist cam surface 90A of the pressure plate 70 and a support-side assist cam surface 160A of the support plate 150. The second cam mechanism 102 is configured to move the pressure plate 70 in a first direction D1 when relative rotation occurs between the pressure plate 70 and the support plate 150 (i.e., the clutch center 40). For example, when the engine speed increases and the rotational driving force input to the input gear 35 and the clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, a rotational force in the first circumferential direction S1 is applied to the pressure plate 70. Therefore, a force in the first direction D1 is generated on the pressure plate 70 due to the action of the pressure-side assist cam surface 90A and the support-side assist cam surface 160A. This increases the pressing force between the drive-side clutch plate 20 and the driven-side clutch plate 22.

[0053] As shown in FIG. 1, the centrifugal clutch mechanism 120 is housed in the clutch housing 30. The centrifugal clutch mechanism 120 is located on the opposite side of the pressure plate 70 from the drive-side clutch plates 20 and the driven-side clutch plates 22 in the axial direction of the output shaft 15 (i.e., direction D). The centrifugal clutch mechanism 120 is disposed on the second direction D2 side of the pressure plate 70. The centrifugal clutch mechanism 120 is held by the clutch housing 30. The centrifugal clutch mechanism 120 is provided so as to be rotatable integrally with the clutch housing 30. The centrifugal clutch mechanism 120 includes a plurality of weight members 122, a holding member 124, and a pressing member 140. When the weight members 122 are at a radially inner position PI (see FIG. 1), the centrifugal clutch mechanism 120 releases the pressing force between the drive-side clutch plates 20 and the driven-side clutch plates 22, thereby establishing a state in which transmission of the rotational driving force of the input member to the output shaft 15 can be blocked. The centrifugal clutch mechanism 120 presses the driving-side clutch plates 20 and the driven-side clutch plates 22 together when the weight member 122 is at a radially outer position PO (see FIG. 7 ), enabling the rotational driving force of the input member to be transmitted to the output shaft 15. The centrifugal clutch mechanism 120 is configured to press the driving-side clutch plates 20 and the driven-side clutch plates 22 together by moving the weight member 122 from a radially inner position PI to a radially outer position PO. The radially inner position PI is an example of a first position. The radially outer position PO is an example of a second position.

[0054] The weight member 122 is movable from a first position PI (see FIG. 1) where the pressing force between the driving-side clutch plates 20 and the driven-side clutch plates 22 is released and the rotational driving force of the input member is prevented from being transmitted to the output shaft 15 as the centrifugal force increases with the rotation of the clutch housing 30, to a second position PO (see FIG. 7) where the driving-side clutch plates 20 and the driven-side clutch plates 22 are pressed together and the rotational driving force of the input member is transmittable to the output shaft 15. The weight member 122 is housed in a holding member 124. The weight member 122 is located radially outward of an axis 28L of the bolt 28. The axis 28L extends in the axial direction of the output shaft 15 (i.e., direction D). The weight member 122 includes a main body 130 formed in a substantially rectangular parallelepiped shape, a first spherical member 131, and a second spherical member 132. The first spherical member 131 and the second spherical member 132 are attached to the main body 130. The first spherical member 131 and the second spherical member 132 are, for example, steel balls. The first spherical member 131 is provided so as to be able to come into contact with the pressing member 140. The second spherical member 132 is provided so as to be able to come into contact with the holding member 124. The first spherical member 131 and the second spherical member 132 are configured to be able to roll. When no centrifugal force is applied, the weight member 122 is held at a radially inner position PI by the spring 135. When centrifugal force is applied, the weight member 122 moves radially outward against the biasing force of the spring 135, and moves to a radially outer position PO.

[0055] 1, the holding member 124 holds the weight member 122 movably between a radially inner position PI and a radially outer position PO. The holding member 124 has an accommodating portion 124A that accommodates the weight member 122. The holding member 124 is held in engagement with a notch 30C formed in the side wall 33 of the clutch housing 30. The holding member 124 rotates integrally with the clutch housing 30.

[0056] As shown in FIG. 1, the pressing member 140 is located between the drive-side clutch plate 20, the driven-side clutch plate 22, and the retaining member 124 in the axial direction of the output shaft 15 (i.e., direction D). The pressing member 140 is located radially outward of the axis 28L of the bolt 28. The pressing member 140 is engaged with and held in a notch 30C formed in the side wall 33 of the clutch housing 30. The pressing member 140 rotates integrally with the clutch housing 30. As shown in FIG. 8, the pressing member 140 is formed in an annular shape. As shown in FIG. 1, the pressing member 140 has an inclined surface 140A on which the first spherical member 131 rolls. The inclined surface 140A is inclined toward the second direction D2 as it goes from the radially inner side to the radially outer side. The pressing member 140 moves in the axial direction (here, the first direction D1) of the output shaft 15 as the weight member 122 moves from a radially inner position PI (see FIG. 1) to a radially outer position PO (see FIG. 7), thereby pressing the driving-side clutch plate 20 and the driven-side clutch plate 22 together. The pressing member 140 is provided so as to be able to press the pressure plate 70. The pressing member 140 is provided so as to be able to press the pressure-side flange 98 of the pressure plate 70.

[0057] In the centrifugal clutch mechanism 120 configured as described above, when no centrifugal force is applied to the weight member 122, the weight member 122 is held at a radially inner position PI (see FIG. 1), and the pressing force between the driving-side clutch plate 20 and the driven-side clutch plate 22 is released. On the other hand, when centrifugal force is applied to the weight member 122, the weight member 122 moves from the radially inner position PI to a radially outer position PO (see FIG. 7). As a result, the pressing member 140 is pressed by the weight member 122 and moves in the first direction D1. As the pressing member 140 moves in the first direction D1, the pressure plate 70 is pressed against the pressing member 140, and the pressure plate 70 moves in the first direction D1. As a result, the pressure side flange 98 and the center side flange 68 press the drive side clutch plate 20 and the driven side clutch plate 22 together, resulting in a pressurized state in which the rotational driving force of the input member can be transmitted to the output shaft 15.

[0058] As described above, in the clutch device 10 of this embodiment, the centrifugal clutch mechanism 120 is located on the opposite side of the pressure plate 70 from the drive-side clutch plates 20 and the driven-side clutch plates 22 in direction D, and the weight member 122 is located radially outward from the axis 28L of the bolt 28 extending in direction D. According to the above aspect, the weight member 122 can sufficiently press the drive-side clutch plates 20 and the driven-side clutch plates 22 together. Furthermore, because the weight member 122 is disposed in a space radially outward from the bolt 28, it is possible to prevent the clutch device 10 from becoming large.

[0059] Second Embodiment Fig. 9 is a cross-sectional view showing a part of a clutch device 210 according to the second embodiment. As shown in Fig. 9, the clutch device 210 includes an output shaft 15, a driving-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 40, a pressure plate 70, a centrifugal clutch mechanism 220, and a support plate 150.

[0060] As shown in FIG. 9 , the centrifugal clutch mechanism 220 is accommodated in the clutch housing 30. At least a portion of the centrifugal clutch mechanism 220 is disposed between the clutch center 40 and the pressure plate 70 in the axial direction of the output shaft 15 (i.e., direction D). The centrifugal clutch mechanism 220 is disposed closer to the second direction D2 than the clutch center 40. The centrifugal clutch mechanism 220 is disposed closer to the first direction D1 than the pressure plate 70. At least a portion of the centrifugal clutch mechanism 220 overlaps with the bolt 28 when viewed from the radial direction. Here, the entire centrifugal clutch mechanism 220 overlaps with the bolt 28 when viewed from the radial direction. The centrifugal clutch mechanism 220 is located closer to the second direction D2 than an end 28D1 of the bolt 28 in the first direction D1. The centrifugal clutch mechanism 220 is located closer to the first direction D1 than an end 28D2 of the bolt 28 in the second direction D2. The centrifugal clutch mechanism 220 is held in the clutch housing 30. The centrifugal clutch mechanism 220 is provided so as to be rotatable integrally with the clutch housing 30. The centrifugal clutch mechanism 220 has a plurality of weight members 122, a holding member 224, a first pressing member 241, and a second pressing member 242. When the weight members 122 are at a radially inner position PI (see FIG. 9), the centrifugal clutch mechanism 220 releases the pressing force between the driving-side clutch plate 20 and the driven-side clutch plate 22, thereby blocking the transmission of the rotational driving force of the input member to the output shaft 15. When the weight members 122 are at a radially outer position PO (see FIG. 10), the centrifugal clutch mechanism 220 presses the driving-side clutch plate 20 and the driven-side clutch plate 22 together, thereby enabling the transmission of the rotational driving force of the input member to the output shaft 15.

[0061] 9, the weight member 122 is housed in a holding member 224. The weight member 122 is located radially outward from the axis 28L of the bolt 28. The first spherical member 131 is provided so as to be able to come into contact with the first pressing member 241. The second spherical member 132 is provided so as to be able to come into contact with the second pressing member 242.

[0062] 9, the holding member 224 holds the weight member 122 movably between a radially inner position PI and a radially outer position PO. The holding member 224 has an accommodating portion 224A that accommodates the weight member 122. The holding member 224 is held by engaging with a notch 30C formed in the side wall 33 of the clutch housing 30. The holding member 224 rotates integrally with the clutch housing 30.

[0063] As shown in FIG. 9 , the first pressing member 241 and the second pressing member 242 are positioned in the axial direction of the output shaft 15 (i.e., direction D) between the driving-side clutch plate 20 and the driven-side clutch plate 22 held by the clutch center 40 and the driving-side clutch plate 20 and the driven-side clutch plate 22 held by the pressure plate 70. The first pressing member 241 and the second pressing member 242 are positioned radially outward of the axis 28L of the bolt 28. The first pressing member 241 and the second pressing member 242 are engaged with and held in a notch 30C formed in the side wall 33 of the clutch housing 30. The first pressing member 241 and the second pressing member 242 are formed in an annular shape. The first pressing member 241 is positioned closer to the first direction D1 than the second pressing member 242. The first pressing member 241 has an inclined surface 241A on which the first spherical member 131 rolls. The inclined surface 241A is inclined toward the second direction D2 as it moves from the radially inner side to the radially outer side. The first pressing member 241 moves in the axial direction (here, the first direction D1) of the output shaft 15 as the weight member 122 moves from a radially inner position PI (see FIG. 9) to a radially outer position PO (see FIG. 10), and presses the driving-side clutch plate 20 and the driven-side clutch plate 22 held by the clutch center 40 into contact with each other. The second pressing member 242 has an inclined surface 242A on which the second spherical member 132 rolls. The inclined surface 242A is inclined toward the first direction D1 as it moves from the radially inner side to the radially outer side. The second pressing member 242 moves in the axial direction (here, the second direction D2) of the output shaft 15 as the weight member 122 moves from a radially inner position PI (see Figure 9) to a radially outer position PO (see Figure 10), thereby pressing the driving side clutch plate 20 and the driven side clutch plate 22 held by the pressure plate 70 together.

[0064] In the centrifugal clutch mechanism 220 configured as described above, when no centrifugal force is applied to the weight member 122, the weight member 122 is held at a radially inner position PI (see FIG. 9), and the pressing force between the driving-side clutch plate 20 and the driven-side clutch plate 22 is released. On the other hand, when a centrifugal force is applied to the weight member 122, the weight member 122 moves from the radially inner position PI to a radially outer position PO (see FIG. 10). As a result, the first pressing member 241 and the second pressing member 242 are pressed by the weight member 122 and move in the first direction D1 and the second direction D2, respectively. As a result, the drive side clutch plates 20 and the driven side clutch plates 22 held on the clutch center 40 by the center side flange 68 and the first pressing member 241 are pressed together and placed in a pressed state, and the drive side clutch plates 20 and the driven side clutch plates 22 held on the pressure plate 70 by the pressure side flange 98 and the second pressing member 242 are pressed together and placed in a pressed state, so that the rotational driving force of the input member can be transmitted to the output shaft 15.

[0065] In the clutch device 210 of this embodiment, at least a portion of the centrifugal clutch mechanism 220 is disposed between the clutch center 40 and the pressure plate 70 in the direction D, and overlaps with the bolt 28 when viewed from the radial direction. According to the above aspect, the centrifugal clutch mechanism 220 can sufficiently press the driving-side clutch plate 20 and the driven-side clutch plate 22 together.

[0066] In the clutch device 210 of this embodiment, the weight member 122 is disposed radially outward of the bolt 28. According to the above aspect, the weight member 122 can sufficiently press the driving-side clutch plate 20 and the driven-side clutch plate 22 together. Furthermore, because the weight member 122 is disposed using the space radially outward of the bolt 28, it is possible to prevent the clutch device 210 from becoming large.

[0067] In the clutch device 210 of this embodiment, when viewed from the radial direction, the entire centrifugal clutch mechanism 220 overlaps with the bolt 28. According to the above aspect, the centrifugal clutch mechanism 220 can be compactly arranged by utilizing the space radially outward of the bolt 28, and therefore, the provision of the centrifugal clutch mechanism 220 can prevent the clutch device 210 from becoming larger in size in the direction D.

[0068] <Third embodiment> Fig. 11 is a cross-sectional view showing a portion of a clutch device 310 according to a third embodiment. As shown in Fig. 11, the clutch device 310 includes an output shaft 15, a driving-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 340, a pressure plate 370, a centrifugal clutch mechanism 220, and a support plate 350. The pressure plate 370 is an example of a first rotating body. The clutch center 340 is an example of a second rotating body. The support plate 350 is an example of a third rotating body.

[0069] As shown in FIG. 11 , the pressure plate 370 is located between the clutch housing 30 and the clutch center 340. The pressure plate 370 is provided so as to be movable (i.e., movable toward and away from) the clutch center 340 in the axial direction of the output shaft 15 (i.e., direction D) and rotatable relative to the clutch center 340. The pressure plate 370 is attached to the radially outer end of the output shaft holding portion 50 of the clutch center 340 so as to be movable in direction D and rotatable relative to the clutch center 340. As shown in FIG. 12A , the pressure plate 370 has a pressure-side assist cam surface 90A. The pressure-side assist cam surface 90A is configured to generate a force in a direction from the pressure plate 370 toward the clutch center 340 (i.e., in a first direction D1) in order to increase the pressing force (pressing force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 370 rotates relative to the clutch center 340 during acceleration, for example. The pressure-side assist cam surface 90A is an example of a first cam surface.

[0070] 11, an insertion hole 90H is formed in the pressure-side cam portion 90. The insertion hole 90H extends in the axial direction of the pressure plate 370 (i.e., direction D). A bolt 28 that connects the pressure plate 370 and the support plate 350 is inserted into the insertion hole 90H. The bolt 28 is an example of a connecting member.

[0071] As shown in FIG. 11, the clutch center 340 is located closer to the first direction D1 than the pressure plate 370. The clutch center 340 is located closer to the second direction D2 than the support plate 350. As shown in FIG. 12A, the clutch center 340 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 be able to come into contact with the pressure-side assist cam surface 90A. The center-side assist cam surface 60A is configured to generate a force in a direction from the pressure plate 370 toward the clutch center 340 (i.e., in the first direction D1) in order to increase the pressing force (pressing force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 370 rotates relative to the clutch center 340 during acceleration, for example. The center-side slipper cam surface 60S is configured to move the pressure plate 370 away from the clutch center 340 in order to reduce the pressing force (pressure contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 370 rotates relative to the clutch center 340 during deceleration, etc. The center-side slipper cam surface 60S is configured to be able to come into contact with a support-side slipper cam surface 160S, which will be described later. The center-side assist cam surface 60A is an example of a second cam surface. The center-side slipper cam surface 60S is an example of a third cam surface.

[0072] As shown in FIG. 11, the support plate 350 is located on the opposite side of the pressure plate 370 with the clutch center 340 sandwiched between them in the axial direction of the output shaft 15 (i.e., direction D). In this example, the support plate 350 is located closer to the clutch center 340 in the first direction D1. The support plate 350 is fixed to the pressure plate 370 by bolts 28. As shown in FIG. 12A, the support plate 350 has a support-side slipper cam surface 160S. The support-side slipper cam surface 160S is configured to be able to come into contact with the center-side slipper cam surface 60S. The support-side slipper cam surface 160S is configured to move the pressure plate 370 away from the clutch center 340 (i.e., to move the pressure plate 370 in the second direction D2) in order to reduce the pressing force (pressure contact force) between the drive-side clutch plate 20 and the driven-side clutch plate 22 when the pressure plate 370 rotates relative to the clutch center 340 during deceleration, etc. The support-side slipper cam surface 160S is an example of a fourth cam surface. The support plate 350 is pressed in the second direction D2 by the driver's operation of a clutch operation lever (not shown). As a result, the pressure plate 370, which is connected to the support plate 350, moves in a direction away from the clutch center 340 (i.e., in the second direction D2).

[0073] As shown in FIG. 12A , the clutch device 310 includes a first cam mechanism 301. The first cam mechanism 301 is configured by a pressure-side assist cam surface 90A of the pressure plate 370 and a center-side assist cam surface 60A of the clutch center 340. The first cam mechanism 301 is configured to move the pressure plate 370 in a first direction D1 when relative rotation occurs between the pressure plate 370 and the clutch center 340. For example, when the engine speed increases and the rotational driving force input to the input gear 35 and the clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 340, a rotational force in the first circumferential direction S1 is applied to the pressure plate 370. Therefore, a force in the first direction D1 is generated on the pressure plate 370 due to the action of the pressure-side assist cam surface 90A and the center-side assist cam surface 60A. This increases the pressing force between the drive-side clutch plate 20 and the driven-side clutch plate 22.

[0074] As shown in FIG. 12B , the clutch device 310 includes a second cam mechanism 302. The second cam mechanism 302 is configured by a center-side slipper cam surface 60S of the clutch center 340 and a support-side slipper cam surface 160S of the support plate 350. The second cam mechanism 302 is configured to move the pressure plate 370 in a second direction D2 when relative rotation occurs between the clutch center 340 and the support plate 350 (i.e., the pressure plate 370). For example, when the rotational speed of the output shaft 15 exceeds the rotational speed of the input gear 35 and the clutch housing 30, causing back torque, a rotational force is applied to the clutch center 340 in a first circumferential direction S1. Therefore, the action of the center-side slipper cam surface 60S and the support-side slipper cam surface 160S moves the pressure plate 370 in the second direction D2, thereby releasing the pressure contact force between the drive-side clutch plate 20 and the driven-side clutch plate 22. This makes it possible to avoid problems with the engine and transmission due to back torque.

[0075] As shown in FIG. 11 , at least a portion of the centrifugal clutch mechanism 220 is disposed between the clutch center 340 and the pressure plate 370 in the axial direction of the output shaft 15 (i.e., direction D). The centrifugal clutch mechanism 220 is disposed closer to the second direction D2 than the clutch center 340. The centrifugal clutch mechanism 220 is disposed closer to the first direction D1 than the pressure plate 370. At least a portion of the centrifugal clutch mechanism 220 overlaps with the bolt 28 when viewed from the radial direction. Here, the entire centrifugal clutch mechanism 220 overlaps with the bolt 28 when viewed from the radial direction. The centrifugal clutch mechanism 220 is located closer to the second direction D2 than the end 28D1 of the bolt 28 in the first direction D1. The centrifugal clutch mechanism 220 is located closer to the first direction D1 than the end 28D2 of the bolt 28 in the second direction D2.

[0076] In the clutch device 310 of this embodiment, at least a portion of the centrifugal clutch mechanism 220 is disposed between the pressure plate 370 and the clutch center 340 in the direction D, and overlaps with the bolt 28 when viewed from the radial direction. According to the above aspect, the centrifugal clutch mechanism 220 can sufficiently press the driving-side clutch plate 20 and the driven-side clutch plate 22 together.

[0077] In the clutch device 310 of this embodiment, the weight member 122 is disposed radially outward from the bolt 28. According to the above aspect, the weight member 122 can sufficiently press the driving-side clutch plate 20 and the driven-side clutch plate 22 together by utilizing the space radially outward from the bolt 28. Furthermore, because the weight member 122 is disposed by utilizing the space radially outward from the bolt 28, it is possible to prevent the clutch device 310 from becoming large.

[0078] In the clutch device 310 of this embodiment, when viewed from the radial direction, the entire centrifugal clutch mechanism 220 overlaps with the bolt 28. According to the above aspect, the centrifugal clutch mechanism 220 can be compactly arranged by utilizing the space radially outward from the axis 28L of the bolt 28, and therefore, the provision of the centrifugal clutch mechanism 220 can prevent the clutch device 310 from becoming larger in size in the direction D.

[0079] <Fourth embodiment> Fig. 13 is a cross-sectional view showing a portion of a clutch device 410 according to the fourth embodiment. As shown in Fig. 13, the clutch device 410 includes an output shaft 15, a driving-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 440, a pressure plate 70, a centrifugal clutch mechanism 120, and a support plate 150. The clutch center 440 is an example of a first rotating body.

[0080] As shown in FIG. 13, the clutch center 440 is accommodated in the clutch housing 30. The clutch center 440 is arranged concentrically with the clutch housing 30. The clutch center 440 rotates together with the output shaft 15. The clutch center 440 includes a first clutch center 441 and a second clutch center 442. The first clutch center 441 is an example of an inner diameter side first rotating body. The second clutch center 442 is an example of an outer diameter side first rotating body.

[0081] 13, the first clutch center 441 has an output shaft holding portion 50 and a center-side cam portion 60. The first clutch center 441 is connected to the output shaft 15. A bolt 28 is fastened to the first clutch center 441. That is, the first clutch center 441 and the support plate 150 are connected by the bolt 28.

[0082] 13, the second clutch center 442 is mounted on the outer periphery of the first clutch center 441 so as to be movable in the axial direction (i.e., direction D) of the output shaft 15. The second clutch center 442 includes a center-side outer periphery wall 45 and a center-side flange 68.

[0083] 13, the centrifugal clutch mechanism 120 is located on the opposite side of the drive-side clutch plates 20 and the driven-side clutch plates 22 across the clutch center 440 in the axial direction of the output shaft 15 (i.e., direction D). The centrifugal clutch mechanism 120 is located closer to the first direction D1 than the clutch center 440.

[0084] As shown in Fig. 13, the weight member 122 is located radially outward from the axis 28L of the bolt 28. When the weight member 122 is located at a radially inner position PI, the weight member 122 is located radially outward from the axis 28L of the bolt 28. As shown in Fig. 14, when the weight member 122 is located at a radially outer position PO, the weight member 122 is located radially outward from the axis 28L of the bolt 28.

[0085] As shown in FIG. 13, the pressing member 140 has an inclined surface 140A on which the first spherical member 131 rolls. The inclined surface 140A is inclined toward the first direction D1 as it moves from the radially inner side to the radially outer side. The pressing member 140 moves in the axial direction (here, the second direction D2) of the output shaft 15 as the weight member 122 moves from a radially inner position PI (see FIG. 13) to a radially outer position PO (see FIG. 14), thereby pressing the driving-side clutch plate 20 and the driven-side clutch plate 22 together. The pressing member 140 is provided so as to be able to press the second clutch center 442. The pressing member 140 is provided so as to be able to press the center-side flange 68 of the second clutch center 442.

[0086] In the centrifugal clutch mechanism 120 configured as described above, when no centrifugal force is applied to the weight member 122, the weight member 122 is held at a radially inner position PI (see FIG. 13), and the pressing force between the driving-side clutch plate 20 and the driven-side clutch plate 22 is released. On the other hand, when centrifugal force is applied to the weight member 122, the weight member 122 moves from the radially inner position PI to a radially outer position PO (see FIG. 14). As a result, the pressing member 140 is pressed by the weight member 122 and moves in the second direction D2. As the pressing member 140 moves in the second direction D2, the second clutch center 442 is pressed against the pressing member 140, and the second clutch center 442 moves in the second direction D2. As a result, the pressure side flange 98 and the center side flange 68 press the drive side clutch plate 20 and the driven side clutch plate 22 together, resulting in a pressurized state in which the rotational driving force of the input member can be transmitted to the output shaft 15.

[0087] In the clutch device 410 of this embodiment, the centrifugal clutch mechanism 120 is located on the opposite side of the clutch center 440 from the drive-side clutch plates 20 and the driven-side clutch plates 22 in direction D, and the pressing members 140 are located radially outward from the axes 28L of the bolts 28. According to the above aspect, the pressing members 140 can sufficiently press the drive-side clutch plates 20 and the driven-side clutch plates 22 together. Furthermore, because the pressing members 140 are arranged using the space radially outward from the bolts 28, the size of the clutch device 410 can be prevented from increasing.

[0088] In the clutch device 410 of this embodiment, the weight member 122 is located radially outward from the axis 28L of the bolt 28. According to the above aspect, the weight member 122 and the pressure contact member 140 can be arranged compactly by utilizing the space radially outward from the axis 28L of the bolt 28, and therefore, the provision of the centrifugal clutch mechanism 120 can prevent the clutch device 410 from becoming larger.

[0089] In the clutch device 410 of this embodiment, the weight member 122 moves from a radially inner position PI to a radially outer position PO, thereby moving the second clutch center 442 in direction D, and thereby pressing the driving side clutch plates 20 and the driven side clutch plates 22 together. According to the above aspect, the pressing member 140 can sufficiently press the driving side clutch plates 20 and the driven side clutch plates 22 together via the second clutch center 442.

[0090] Fifth Embodiment 15 is a cross-sectional view showing a portion of a clutch device 510 according to a fifth embodiment. As shown in Fig. 15, the clutch device 510 includes an output shaft 15, a driving-side clutch plate 20, a driven-side clutch plate 22, a clutch housing 30, a clutch center 340, a pressure plate 370, a centrifugal clutch mechanism 120, and a support plate 350.

[0091] As shown in Figure 15, the centrifugal clutch mechanism 120 is located on the opposite side of the drive-side clutch plates 20 and the driven-side clutch plates 22 with the pressure plate 370 sandwiched between them in the axial direction of the output shaft 15 (i.e., direction D). The centrifugal clutch mechanism 120 is located on the second direction D2 side of the pressure plate 370. The pressing member 140 is located radially outward of the axis 28L of the bolt 28. The pressing member 140 is provided so as to be able to press against the pressure plate 370. The pressing member 140 is provided so as to be able to press against the pressure side flange 98 of the pressure plate 370. The weight member 122 is located radially outward of the axis 28L of the bolt 28.

[0092] In the clutch device 510 of this embodiment, the centrifugal clutch mechanism 120 is located on the opposite side of the pressure plate 370 from the drive-side clutch plates 20 and the driven-side clutch plates 22 in direction D, and the pressing members 140 are located radially outward from the axes 28L of the bolts 28. According to the above aspect, the pressing members 140 can sufficiently press the drive-side clutch plates 20 and the driven-side clutch plates 22 together. Furthermore, because the pressing members 140 are arranged using the space radially outward from the bolts 28, the size of the clutch device 510 can be prevented from increasing.

[0093] In the clutch device 510 of this embodiment, the weight member 122 is located radially outward from the axis 28L of the bolt 28. According to the above aspect, the weight member 122 and the pressure contact member 140 can be arranged compactly by utilizing the space radially outward from the axis 28L of the bolt 28, and therefore, the provision of the centrifugal clutch mechanism 120 can prevent the clutch device 510 from becoming larger.

[0094] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0095] The first cam mechanism 101 may be configured to move the pressure plate 70 in a first direction D1 when relative rotation occurs between the clutch center 40 and the pressure plate 70. The second cam mechanism 102 may be configured to move the pressure plate 70 in a second direction D2 when relative rotation occurs between the pressure plate 70 and the support plate 150 (i.e., the clutch center 40).

[0096] The first cam mechanism 301 may be configured to move the pressure plate 370 in the second direction D2 when relative rotation occurs between the pressure plate 370 and the clutch center 340. The second cam mechanism 302 may be configured to move the pressure plate 370 in the first direction D1 when relative rotation occurs between the clutch center 340 and the support plate 350 (i.e., the pressure plate 370). [Explanation of symbols]

[0097] 10 Clutch device 15 Output shaft (output member) 20 Drive side clutch plate 22 Driven side clutch plate 28 Bolts (connecting members) 28L axis 30 Clutch housing 40 Clutch center (first rotating body) 60S Center side slipper cam surface (first cam surface) 70 Pressure plate (second rotating body) 90A Pressure side assist cam surface (third cam surface) 90S Pressure side slipper cam surface (second cam surface) 101 First cam mechanism 102 Second cam mechanism 120 Centrifugal clutch mechanism 122 Weight member 124 Storage member 140 Pressure welding member 150 Support plate (third rotating body) 160A Support side assist cam surface (4th cam surface)

Claims

[Claim 1] A clutch device that transmits or interrupts the rotational drive force of an input member to an output member, a first rotor that is housed in a clutch housing that holds a plurality of drive-side clutch plates that are rotationally driven by rotational driving of the input member, that is connected to the output member, and that has a first cam surface; a second rotor having a second cam surface and a third cam surface configured to be able to come into contact with the first cam surface, and being provided so as to be movable in the axial direction of the output member and rotatable relative to the first rotor, and holding at least one of a plurality of driven-side clutch plates arranged alternately with the driving-side clutch plates; a third rotating body fixed to the first rotating body so as to be located on the opposite side of the first rotating body with the second rotating body sandwiched in the axial direction, and having a fourth cam surface configured to be able to come into contact with the third cam surface; at least one connecting member connecting the first rotating body and the third rotating body; a first cam mechanism that is constituted by the first cam surface and the second cam surface and that is configured to move the second rotor from one side to the other in the axial direction when relative rotation occurs between the first rotor and the second rotor; a second cam mechanism that is constituted by the third cam surface and the fourth cam surface and that is configured to move the second rotating body from the other side to the one side in the axial direction when relative rotation occurs between the second rotating body and the third rotating body; a centrifugal clutch mechanism including: a plurality of weight members that are movable from a first position, at which the pressing force between the driving-side clutch plates and the driven-side clutch plates is released and the transmission of the rotational drive force of the input member to the output member, to a second position, at which the driving-side clutch plates and the driven-side clutch plates are pressed together and the rotational drive force of the input member can be transmitted to the output member, as the centrifugal force increases with the rotation of the clutch housing; a pressing member that is held by the clutch housing and moves in the axial direction as the weight member moves from the first position to the second position, thereby pressing the driving-side clutch plates and the driven-side clutch plates together; and a holding member that houses the weight member and is held by the clutch housing, the centrifugal clutch mechanism is located on the opposite side of the second rotor from the driving-side clutch plate and the driven-side clutch plate in the axial direction, the weight member is located radially outward of an axis of the connecting member extending in the axial direction, the second rotor has a pressing surface capable of pressing the driving-side clutch plate and the driven-side clutch plate, and a pressed surface located on the opposite side of the pressing surface in the axial direction, The clutch device, wherein the pressure contact member is configured to be able to press the pressed surface.

Images