Clutch device

Abstract

To suppress a spring storage part from being damaged when assembling a clutch center and a pressure plate.SOLUTION: A clutch device 10 includes a clutch center 40 and a pressure plate 70. The pressure plate 70 includes a boss part 84 extending in a first direction D1. The clutch center 40 includes: a center side cam hole 43H into which the boss part 84 is inserted; and a spring storage part 54 for storing a pressure spring 25. The spring storage part 54 includes: a storage recess part 55 formed so as to be recessed in a second direction D2 and for storing the pressure spring 25; and a wall surface 57 for partitioning the storage recess part 55. The wall surface 57 includes: a first wall surface part 57A having a first curvature when viewed from the axial direction of an output shaft 15; and a second wall surface part 57B having a second curvature smaller than the first curvature.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] For example, Patent Document 1 discloses a clutch device that includes a clutch center that rotates together with an output shaft and a pressure plate that is movable toward and away from the clutch center. The pressure plate is configured to be able to press an input side rotating plate and an output side rotating plate. In the clutch device, the clutch center and the pressure plate are assembled together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6894792 [Patent Document 2] Patent No. 6265489 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the clutch device of Patent Document 1, when the clutch center and pressure plate are assembled to the output shaft, a dedicated anti-rotation tool (see Patent Document 2, for example) is used to prevent the clutch center and pressure plate from rotating together with the output shaft. In the example of Patent Document 1, the anti-rotation tool is attached to a spring housing portion that houses a pressure spring, thereby preventing the clutch center and pressure plate from rotating together with the output shaft. However, the portion of the anti-rotation tool that comes into contact with the spring housing portion is flat, whereas the spring housing portion is formed in a circular shape when viewed from the axial direction of the output shaft, so there was a risk that the anti-rotation tool would damage the spring housing portion during assembly.

[0005] The present invention has been made in consideration of the above-mentioned points, and its object is to provide a clutch device that can prevent the spring accommodating portion from being damaged when assembling the clutch center and the pressure plate. [Means for solving the problem]

[0006] a clutch housing that holds a plurality of input side rotating plates that are rotationally driven by the rotational drive of the input shaft and that rotates together with the output shaft; and a pressure plate that is capable of approaching or moving away from the clutch center and rotatably relative to the clutch center and can press a plurality of output side rotating plates that are arranged alternately with the input side rotating plates and the input side rotating plates. When a direction in which the pressure plate moves is defined as a moving direction, a direction from one side of the moving direction to the other is defined as a first direction, and a direction from the other side of the moving direction to the one side is defined as a second direction, one of the pressure plate and the clutch center has a boss portion extending in a first direction, and the other of the pressure plate and the clutch center has a through hole that is formed in the moving direction and into which the boss portion is inserted, and a spring accommodating portion that accommodates a pressure spring that urges the pressure plate in a direction toward the clutch center in relation to the moving direction, The spring accommodating portion includes an accommodating recess formed to be recessed in the second direction and accommodating the pressure spring, and a wall surface partitioning the accommodating recess, and the wall surface includes a first wall surface portion having a first curvature when viewed in the axial direction of the output shaft, and a second wall surface portion having a second curvature smaller than the first curvature.

[0007] According to the clutch device of the present invention, the wall surface of the spring housing portion includes a first wall portion having a first curvature and a second wall portion having a second curvature smaller than the first curvature when viewed from the axial direction of the output shaft. According to the above aspect, for example, when the clutch center and the pressure plate are assembled to the output shaft, a rotation-stop tool can be attached to the second wall portion of the spring housing portion. Here, since the curvature of the second wall portion is smaller than the curvature of the first wall portion, the stress per unit area transmitted from the rotation-stop tool to the second wall portion is reduced. This makes it possible to prevent the second wall portion of the spring housing portion from being damaged by the rotation-stop tool. Effect of the Invention

[0008] According to the present invention, it is possible to provide a clutch device that can prevent the spring accommodating portion from being damaged when the clutch center and the pressure plate are assembled. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a clutch device according to one embodiment. [Diagram 2] FIG. 2 is a perspective view of the clutch center according to one embodiment. [Diagram 3] FIG. 3 is a perspective view of the clutch center according to one embodiment. [Figure 4] FIG. 4 is a plan view of the clutch center according to one embodiment. [Diagram 5] FIG. 5 is a perspective view of a pressure plate according to one embodiment. [Figure 6] FIG. 6 is a perspective view showing a state in which the clutch center and the pressure plate according to one embodiment are assembled. [Figure 7] FIG. 7 is a plan view showing a state in which the clutch center and the pressure plate according to one embodiment are assembled. [Figure 8A] FIG. 8A is a schematic diagram for explaining the action of the center side assist cam surface and the pressure side assist cam surface. [Figure 8B] FIG. 8B is a schematic diagram for explaining the action of the center-side slipper cam surface and the pressure-side slipper cam surface. [Figure 9] FIG. 9 is a plan view showing a schematic diagram of the anti-rotation tool. [Figure 10] FIG. 10 is a plan view showing the positional relationship when the anti-rotation tool is attached to the clutch center. [Figure 11] FIG. 11 is a cross-sectional view of a clutch device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of a clutch device according to the present invention will be described with reference to the drawings. Note that the embodiment described here is not intended to limit the present invention in any particular way. In addition, the same reference numerals are used for members and parts that perform the same functions, and duplicated descriptions will be omitted or simplified as appropriate.

[0011] 1 is a cross-sectional view of a clutch device 10 according to this 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 shaft (crankshaft) of 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 shaft to a driving wheel (rear wheel) via the output shaft 15. The clutch device 10 is disposed between the engine and the transmission.

[0012] In the following description, the direction in which the pressure plate 70 of the clutch device 10 moves is referred to as direction D, the direction from one side of the direction D to the other side is referred to as first direction D1, and the direction from the other side of the direction D to the one side is referred to as second direction D2. The direction D is an example of a moving direction. The circumferential direction of the clutch center 40 and the pressure plate 70 is referred to as circumferential direction S, the direction from one side to the other with respect to the circumferential direction S is referred to as first circumferential direction S1 (see FIG. 2), and the direction from the other side to the one side is referred to as second direction S2 (see FIG. 2). 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 the direction D. The pressure plate 70 and the clutch center 40 rotate in the first circumferential direction S1. However, the above directions are merely defined for the convenience of description, and do not limit the installation mode of the clutch device 10, nor limit the present invention.

[0013] 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 bearing 15A. The output shaft 15 fixedly supports a clutch center 40 via a collar 15C and a nut 15N. 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.

[0014] 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 first direction D1 from an edge of the bottom wall 31. The clutch housing 30 holds a plurality of input side rotating plates 20.

[0015] As shown in Fig. 1, an input gear 35 is provided on a bottom wall 31 of the clutch housing 30. The input gear 35 is fixed to the bottom wall 31 by a rivet 35B via a torque damper 35A. The input gear 35 meshes with a drive gear (not shown) that rotates by the rotational drive of the input shaft of the engine. The input gear 35 is rotated integrally with the clutch housing 30 independently of the output shaft 15.

[0016] The input side rotating plate 20 is rotationally driven by the rotational drive of the input shaft. As shown in Fig. 1, the input side rotating plate 20 is held on the inner circumferential surface of a side wall 33 of the clutch housing 30. The input side rotating plate 20 is held in the clutch housing 30 by spline fitting. The input side rotating plate 20 is provided so as to be displaceable along the axial direction of the clutch housing 30 (i.e., direction D). The input side rotating plate 20 is provided so as to be rotatable integrally with the clutch housing 30.

[0017] The input side rotating plate 20 is a member that is pressed against the output side rotating plate 22. The input side rotating plate 20 is formed in an annular shape. The input side rotating plate 20 is formed by aluminum die casting. Friction material (not shown) made of multiple pieces of paper is attached to the front and back surfaces of the input side rotating plate 20. Grooves several hundred μm deep are formed between the friction materials to hold clutch oil.

[0018] 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 flange 68 extending radially outward from the outer circumferential edge of the main body 42. The main body 42 protrudes in a second direction D2 beyond the flange 68. The clutch center 40 holds an input side rotating plate 20 and a plurality of output side rotating plates 22 arranged alternately in the direction D. The clutch center 40 is driven to rotate together with the output shaft 15.

[0019] As shown in FIG. 2, the main body 42 includes an output shaft holding portion 50 provided in the center of the main body 42, an outer peripheral wall 45 located radially outward from the output shaft holding portion 50, and a plurality of center side cam portions 60 connected to the output shaft holding portion 50 and the outer peripheral wall 45.

[0020] As shown in FIG. 2, the output shaft holding portion 50 is formed in a cylindrical shape. The output shaft holding portion 50 extends in the second direction D2. An end portion of the output shaft holding portion 50 on the second direction D2 side is located closer to the second direction D2 side than the center side cam portion 60. An insertion hole 51 into which the output shaft 15 is inserted and spline-fitted is formed through the output shaft holding portion 50. An inner peripheral 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.

[0021] As shown in FIG. 2, a spline fitting portion 46 is provided on an outer peripheral surface 45A of the outer peripheral wall 45. The spline fitting portion 46 has a plurality of center side fitting teeth 47 extending in the axial direction of the clutch center 40 along the outer peripheral surface 45A of the outer peripheral wall 45, and a plurality of 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 the output side rotating plate 22. The center side fitting teeth 47 are arranged 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 in the same shape. The center side fitting teeth 47 protrude radially outward from the outer peripheral surface 45A of the outer peripheral wall 45.

[0022] The output side rotating plate 22 is held by the spline fitting portion 46 of the clutch center 40 and the spline fitting portion 76 of the pressure plate 70, which will be described later. A part of the output side rotating plate 22 is held by spline fitting to the center side fitting teeth 47 and the spline grooves 48 of the clutch center 40. Another part of the output side rotating plate 22 is held by spline fitting to the pressure side fitting teeth 77 (see FIG. 5) and the spline grooves 78 (see FIG. 5), which will be described later, of the pressure plate 70. The output side rotating plate 22 is provided so as to be displaceable along the axial direction of the clutch center 40. The output side rotating plate 22 is provided so as to be rotatable integrally with the clutch center 40.

[0023] The output side rotating plate 22 is a member pressed against the input side rotating plate 20. The output side rotating plate 22 is formed in an annular shape. The output side rotating plate 22 is formed by punching out a thin plate material made of SPCC material into an annular shape. The friction material provided on the input side rotating plate 20 may be provided on the output side rotating plate 22 instead of the input side rotating plate 20, or may be provided on both the input side rotating plate 20 and the output side rotating plate 22.

[0024] The center side cam portion 60 is formed in a platform shape having a cam surface made of an inclined surface constituting an Assist & Slipper (registered trademark) mechanism that generates an assist torque, which is a force that increases the pressing force (pressure contact force) between the input side rotating plate 20 and the output side rotating plate 22, or a slipper torque, which is a force that causes the input side rotating plate 20 and the output side rotating plate 22 to separate early and transition to a half-clutch state. The center side cam portion 60 is formed on the main body 42. An end portion of the center side cam portion 60 on the second direction D2 side is located on the second direction D2 side relative to the outer peripheral wall 45. The center side cam portions 60 are disposed 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.

[0025] As shown in FIG. 2, the center-side cam portion 60 is located radially outside 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 in a direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force (pressing force) between the input side rotating plate 20 and the output side rotating plate 22 when the clutch center 40 rotates relative to the pressure plate 70. In this embodiment, when the force is generated, the position of the pressure plate 70 relative to the clutch center 40 does not change, and the pressure plate 70 does not need to physically approach the clutch center 40. Note that the pressure plate 70 may be physically displaced relative to the clutch center 40. The center-side slipper cam surface 60S is configured to move the pressure plate 70 away from the clutch center 40 in order to reduce the pressing force (pressure contact force) between the input-side rotating plate 20 and the output-side rotating plate 22 when the clutch center 40 rotates relative to the pressure plate 70. In the center-side cam portions 60 adjacent to each other in the circumferential direction S, the center-side assist cam surface 60A of one center-side cam portion 60L and the center-side slipper cam surface 60S of the other center-side cam portion 60M are disposed opposite each other in the circumferential direction S.

[0026] As shown in FIG. 3 and FIG. 4, the clutch center 40 includes a spring accommodating portion 54. The spring accommodating portion 54 is formed in the main body 42. More specifically, the spring accommodating portion 54 is formed in the center-side cam portion 60. The spring accommodating portion 54 accommodates the pressure spring 25 (see FIG. 1). In this embodiment, the clutch center 40 includes three spring accommodating portions 54. The three spring accommodating portions 54 are disposed at equal intervals in the circumferential direction S of the clutch center 40. The number of the spring accommodating portions 54 is not limited to three. The spring accommodating portion 54 is located on the second circumferential direction S2 side of the center-side slipper cam surface 60S. The spring accommodating portion 54 is located on the first circumferential direction S1 side of the center-side assist cam surface 60A.

[0027] As shown in Figures 3 and 4, the spring accommodating portion 54 includes a cylindrical accommodating recess 55 with a bottom, an opening 56, and a wall surface 57 that defines the accommodating recess 55. The accommodating recess 55 is formed so as to be recessed in the second direction D2. The accommodating recess 55 is formed so as to be recessed in the second direction D2 from the back surface 60B of the center-side cam portion 60. The accommodating recess 55 accommodates the pressure spring 25 (see Figure 1). The opening 56 is formed at an end of the accommodating recess 55 in the first direction D1.

[0028] As shown in FIG. 4, the wall surface 57 includes a first wall surface portion 57A, a second wall surface portion 57B, and a bottom wall portion 57C. The first wall surface portion 57A and the second wall surface portion 57B extend in a direction D. The first wall surface portion 57A is continuously formed from the opening 56 to the bottom wall portion 57C in the direction D. The second wall surface portion 57B is continuously formed from the opening 56 to the bottom wall portion 57C in the direction D. The first wall surface portion 57A and the second wall surface portion 57B are formed so as to be able to come into contact with the side portion of the pressure spring 25. The first wall surface portion 57A is in surface contact with the side portion of the pressure spring 25, for example. The second wall surface portion 57B is in point contact with the side portion of the pressure spring 25, for example. The bottom wall portion 57C is continuous with the first wall surface portion 57A and the second wall surface portion 57B. The bottom wall portion 57C extends in a direction perpendicular to the direction D. As shown in FIG. 1, the bottom wall portion 57C contacts the end portion 25D2 of the pressure spring 25 on the second direction D2 side. As shown in FIG. 4, when viewed from the axial direction of the output shaft 15, the first wall portion 57A has a first curvature, and the second wall portion 57B has a second curvature. The first wall portion 57A is curved (for example, arc-shaped). In this embodiment, the second curvature is zero. That is, the second wall portion 57B is linear when viewed from the axial direction of the output shaft 15. The second wall portion 57B may be curved (arc-shaped).

[0029] As shown in Fig. 4, when viewed from the axial direction of the output shaft 15, the second wall surface portion 57B is located radially outward of a circle CL that is centered on the axis 15CL of the output shaft 15 and passes through the center 54CL of the spring accommodating portion 54. The second wall surface portion 57B is formed to a length that allows the anti-rotation tool 150 (see Fig. 9) described later to come into contact with it. More specifically, the length of the second wall surface portion 57B in the direction D and the length of the circumferential direction S are formed to a length that allows the anti-rotation tool 150 (here, a first locking portion 151A and a second locking portion 152A described later) to come into contact with it. When viewed in the axial direction of the output shaft 15, the second wall portion 57B includes a left second wall portion 57BL located on the left side of a straight line SL passing through the axis 15CL of the output shaft 15 and the center 54CL of the spring accommodating portion 54, a right second wall portion 57BR located on the right side of the straight line SL, a left inner diameter side second wall portion 57BLL connecting the left end of the left second wall portion 57BL to the left end of the first wall portion 57A, a right inner diameter side second wall portion 57BRR connecting the right end of the right second wall portion 57BR to the right end of the first wall portion 57A, and a central second wall portion 57BC connecting the right end of the left second wall portion 57BL to the left end of the right second wall portion 57BR.

[0030] 7, the spring accommodating portion 54 includes a first spring accommodating portion 54A and a second spring accommodating portion 54B aligned in the circumferential direction S. The first spring accommodating portion 54A is positioned closer to the first circumferential direction S1 than the second spring accommodating portion 54B. When viewed from the axial direction of the output shaft 15, the second wall surface portion 57B (more specifically, the left second wall surface portion 57BL and the left inner diameter side second wall surface portion 57BLL) of the first spring accommodating portion 54A is positioned closer to the first circumferential direction S1 than a first straight line SL1 passing through the axis center 15CL of the output shaft 15 and the center 54ACL of the first spring accommodating portion 54A. The second wall portion 57B of the second spring accommodating portion 54B (more specifically, the right side second wall portion 57BR and the right inner diameter side second wall portion 57BRR) is located on the second circumferential direction S2 side of the second straight line SL2 passing through the axis 15CL of the output shaft 15 and the center 54BCL of the second spring accommodating portion 54B, when viewed from the axial direction of the output shaft 15.

[0031] 1, the pressure spring 25 is housed in the spring housing 54. The pressure spring 25 biases the pressure plate 70 in a direction toward the clutch center 40 with respect to the direction D (i.e., the first direction D1). The pressure spring 25 is, for example, a coil spring formed by winding spring steel in a spiral shape.

[0032] As shown in FIG. 2 and FIG. 4, the clutch center 40 has a center-side cam hole 43H penetrating a part of the main body 42. The center-side cam hole 43H is an example of a through hole. The center-side cam hole 43H penetrates the main body 42 in the direction D. The center-side cam hole 43H extends from the side of the output shaft holding portion 50 to the outer peripheral wall 45. The center-side cam hole 43H is formed between the center-side assist cam surface 60A and the center-side slipper cam surface 60S of the adjacent center-side cam portion 60. A boss portion 84 (see FIG. 5) of the pressure plate 70, which will be described later, is inserted into the center-side cam hole 43H. When viewed from the axial direction of the clutch center 40, the center-side assist cam surface 60A and a part of the center-side cam hole 43H overlap each other.

[0033] As shown in FIG. 1, the pressure plate 70 is accommodated in the clutch housing 30. The pressure plate 70 is located between the clutch housing 30 and the clutch center 40. The pressure plate 70 is provided so as to be able to approach or separate from the clutch center 40 and to be able to rotate relative to the clutch center 40. The pressure plate 70 is configured to be able to press the input side rotating plate 20 and the output side rotating plate 22. The pressure plate 70 is arranged concentrically with the clutch center 40 and the clutch housing 30. The pressure plate 70 has a main body 72 and a flange 98 that is connected to the outer circumferential edge of the main body 72 on the second direction D2 side and extends radially outward. The main body 72 protrudes in the first direction D1 beyond the flange 98. The pressure plate 70 holds a plurality of output side rotating plates 22 that are arranged alternately with the input side rotating plate 20.

[0034] As shown in FIG. 5, the main body 72 includes an annular base wall 73, a fitting hole 80 provided in the center of the base wall 73, an outer peripheral wall 75 located radially outside the base wall 73 and extending toward the first direction D1, and a plurality of pressure side cam portions 90 connected to the base wall 73 and the outer peripheral wall 75.

[0035] 5, the flange 98 extends radially outward from the outer circumferential edge of the main body 72. The flange 98, together with the flange 68 of the clutch center 40, sandwiches the input side rotating plate 20 and the output side rotating plate 22. The flange 98 is a member that applies a pressing force to the input side rotating plate 20 and the output side rotating plate 22.

[0036] 5, the fitting hole 80 is formed in the center of the main body 72. The fitting hole 80 penetrates the base wall 73 in the direction D. Into the fitting hole 80, the output shaft holding portion 50 of the clutch center 40 is inserted.

[0037] As shown in FIG. 5, a splined fitting portion 76 is provided on an outer peripheral surface 75A of the outer peripheral wall 75. The splined fitting portion 76 has a plurality of pressure side fitting teeth 77 extending in the axial direction of the pressure plate 70 along the outer peripheral surface 75A of the outer peripheral wall 75, and a plurality of 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 the output side rotating plate 22. The pressure side fitting teeth 77 are aligned in the circumferential direction S. The pressure side fitting teeth 77 are formed in the same shape. The pressure side fitting teeth 77 protrude radially outward from the outer peripheral surface 75A of the outer peripheral wall 75.

[0038] The pressure-side cam portion 90 is formed in a platform shape having a cam surface made of an inclined surface constituting an Assist & Slipper (registered trademark) mechanism that slides on the center-side cam portion 60 to generate an assist torque or a slipper torque. The pressure-side cam portion 90 is formed so as to protrude in a first direction D1 beyond the flange 98. As shown in FIG. 5, the pressure-side cam portions 90 are disposed at equal intervals in the circumferential direction S of the pressure plate 70. In this embodiment, the pressure plate 70 has three pressure-side cam portions 90, but the number of pressure-side cam portions 90 is not limited to three.

[0039] As shown in FIG. 5, the pressure side cam portion 90 is located radially outside the fitting hole 80. The pressure side cam portion 90 has a pressure side assist cam surface 90A and a pressure side slipper cam surface 90S. The pressure side assist cam surface 90A is configured to be able to come into contact with the center side assist cam surface 60A. The pressure side assist cam surface 90A is configured to generate a force in a direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force (pressing force) between the input side rotating plate 20 and the output side rotating plate 22 when the pressure plate 70 rotates relative to the clutch center 40. 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 (pressure contact force) between the input side rotating plate 20 and the output side rotating plate 22 when the pressure plate 70 rotates relative to the clutch center 40. In the pressure-side cam portions 90 adjacent to each other in the circumferential direction S, the pressure-side assist cam surface 90A of one pressure-side cam portion 90L and the pressure-side slipper cam surface 90S of the other pressure-side cam portion 90M are disposed opposite each other in the circumferential direction S.

[0040] Here, the action of the center side cam portion 60 and the pressure side cam portion 90 will be described. When the engine speed increases and the rotational driving force input to the input gear 35 and the clutch housing 30 can be transmitted to the output shaft 15 via the clutch center 40, a rotational force in the first circumferential direction S1 is applied to the pressure plate 70 as shown in Fig. 8A. Therefore, 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 pressing force between the input side rotating plate 20 and the output side rotating plate 22.

[0041] On the other hand, when the rotation speed of the output shaft 15 exceeds the rotation speed of the input gear 35 and the clutch housing 30 and back torque is generated, a rotational force in the first circumferential direction S1 is applied to the clutch center 40 as shown in Fig. 8B. Therefore, the action of the center side slipper cam surface 60S and the pressure side slipper cam surface 90S moves the pressure plate 70 in the second direction D2 to release the pressure contact force between the input side rotating plate 20 and the output side rotating plate 22. This makes it possible to avoid malfunctions of the engine and transmission due to back torque.

[0042] As shown in FIG. 5, the pressure plate 70 has a pressure-side cam hole 73H penetrating a part of the base wall 73. The pressure-side cam hole 73H penetrates the base wall 73 in the direction D. The pressure-side cam hole 73H is located radially outward of the fitting hole 80. The pressure-side cam hole 73H extends from the side of the fitting hole 80 to the outer circumferential wall 75. The pressure-side cam hole 73H is formed penetrating between adjacent pressure-side cam portions 90. The pressure-side cam hole 73H is formed penetrating between the pressure-side assist cam surface 90A and the pressure-side slipper cam surface 90S of the adjacent pressure-side cam portions 90. When viewed from the axial direction of the pressure plate 70, the pressure-side assist cam surface 90A and a part of the pressure-side cam hole 73H overlap.

[0043] As shown in FIG. 5, the pressure plate 70 has a plurality of boss portions 84 (three in this embodiment). The plurality of boss portions 84 are disposed at equal intervals in the circumferential direction S. The boss portion 84 is formed in a cylindrical shape. The boss portion 84 is located radially outward from the fitting hole 80. The boss portion 84 extends from the base wall 73 in the first direction D1. The boss portion 84 is provided on the pressure side cam portion 90. The boss portion 84 is located between the pressure side assist cam surface 90A and the pressure side slipper cam surface 90S with respect to the circumferential direction S. As shown in FIG. 6, the boss portion 84 is inserted into the center side cam hole 43H. The boss portion 84 is formed with a screw hole 84H into which the bolt 28 (see FIG. 1) is inserted. The screw hole 84H extends in the axial direction of the pressure plate 70.

[0044] As shown in FIG. 1, the clutch device 10 includes a lifter plate 100. The lifter plate 100 is a member for displacing the pressure plate 70 in the direction D. The lifter plate 100 contacts an end 25D1 of the pressure spring 25 on the first direction D1 side. The lifter plate 100 is fixed to the pressure plate 70 by a bolt 28. The lifter plate 100 rotates integrally with the pressure plate 70. The lifter plate 100 moves in the direction D with respect to the clutch center 40 and rotates relatively to the clutch center 40. The lifter plate 100 is actuated by a clutch release mechanism (not shown). Here, the clutch release mechanism is a mechanical device that is actuated by the driver's operation of a clutch operation lever (not shown) in a vehicle such as a motorcycle on which the clutch device 10 is mounted.

[0045] 6 and 7 are a perspective view and a plan view showing a state in which the clutch center 40 and the pressure plate 70 are assembled (hereinafter referred to as an assembled state). In the state shown in FIG. 6 and FIG. 7, the pressure side assist cam surface 90A and the center side assist cam surface 60A are not in contact with each other, and the pressure side slipper cam surface 90S and the center side slipper cam surface 60S are not in contact with each other. At this time, the pressure plate 70 is closest to the clutch center 40. In the assembled state, the pressure side assist cam surface 90A and the center side assist cam surface 60A may be in contact with each other, and the pressure side slipper cam surface 90S and the center side slipper cam surface 60S may not be in contact with each other. In FIG. 6, the input side rotating plate 20, the output side rotating plate 22, and the pressure spring 25 are omitted for convenience of explanation.

[0046] Next, a description will be given of the assembly of the clutch center 40 and the pressure plate 70. Here, a description will be given of the process of assembling the clutch center 40 to the output shaft 15. When assembling the clutch center 40 to the output shaft 15, a rotation-stopping tool 150 (see FIG. 9) is used.

[0047] As shown in FIG. 9, the anti-rotation tool 150 (e.g., a universal holder) is a tool used to prevent the clutch center 40 from rotating together with the nut 15N when the clutch center 40 is assembled to the output shaft 15, and to prevent the clutch center 40, the pressure plate 70, and the output shaft 15 from rotating together (so-called co-rotation). The anti-rotation tool 150 includes a first arm portion 151, a second arm portion 152, a connecting pin 154 that connects the first arm portion 151 and the second arm portion 152, and an opening adjustment mechanism 156 that adjusts the opening of the first arm portion 151 and the second arm portion 152. A first locking portion 151A and a second locking portion 152A that lock onto the second wall surface portion 57B of the spring accommodating portion 54 are provided at the tips of the first arm portion 151 and the second arm portion 152, respectively. The first locking portion 151A and the second locking portion 152A are formed in a plate shape. The first locking portion 151A and the second locking portion 152A extend in a direction perpendicular to the direction in which the first arm portion 151 and the second arm portion 152 extend. In this embodiment, the portions of the first locking portion 151A and the second locking portion 152A that contact the second wall surface portion 57B are flat. The operator holds the rear end portion 151R of the first arm portion 151. The connecting pin 154 connects the middle portion of the first arm portion 151 and the rear end portion of the second arm portion 152. The first arm portion 151 and the second arm portion 152 are configured to be freely opened and closed with the connecting pin 154 as a fulcrum. The opening adjustment mechanism 156 is bridged between the first arm portion 151 and the second arm portion 152. The opening adjustment mechanism 156 is located between the first locking portion 151A and the second locking portion 152A and the connecting pin 154.

[0048] When assembling the clutch center 40 to the output shaft 15, the worker first prepares the collar 15C, the nut 15N, and the anti-rotation tool 150 with the clutch housing 30, the input gear 35, the input rotating plate 20, the output rotating plate 22, the clutch center 40, and the pressure plate 70 respectively arranged on the output shaft 15. Next, the worker fits the collar 15C onto the tip of the output shaft 15, and then screws in the nut 15N. In the process of screwing in the nut 15N, the worker attaches the anti-rotation tool 150 to the clutch center 40 to prevent the clutch center 40 and the pressure plate 70 from rotating together with the output shaft 15. Specifically, as shown in FIG. 10, the worker tightens the nut 15N using a tool (not shown) while the flat surfaces 151AA and 152AA of the first and second locking parts 151A and 152A of the anti-rotation tool 150, which are formed in a flat shape, are locked to the second wall surface 57B of the spring accommodating part 54. At this time, the clutch center 40 tries to rotate together with the nut 15N, but the second wall surface 57B hits the first and second locking parts 151A and 152A of the anti-rotation tool 150 and prevents the clutch center 40 from rotating together with the nut 15N. In this way, the worker can assemble the clutch center 40 to the output shaft 15 while suppressing the clutch center 40 and the pressure plate 70 from rotating together with the output shaft 15. Then, the worker attaches the pressure spring 25 and the lifter plate 100 to the clutch center 40 and the pressure plate 70 attached to the output shaft 15. For ease of explanation, FIG. 10 shows only the first locking portion 151A and the second locking portion 152A of the anti-rotation tool 150.

[0049] As described above, according to the clutch device 10 of this embodiment, the wall surface 57 of the spring accommodating portion 54 includes the first wall surface portion 57A having a first curvature and the second wall surface portion 57B having a second curvature smaller than the first curvature when viewed from the axial direction of the output shaft 15. According to the above aspect, for example, when the clutch center 40 and the pressure plate 70 are assembled to the output shaft 15, the anti-rotation tool 150 can be attached to the second wall surface portion 57B of the spring accommodating portion 54. Here, since the curvature of the second wall surface portion 57B is smaller than the curvature of the first wall surface portion 57A, the stress per unit area transmitted from the anti-rotation tool 150 to the second wall surface portion 57B is reduced. This makes it possible to prevent the anti-rotation tool 150 from damaging the second wall surface portion 57B of the spring accommodating portion 54.

[0050] In the clutch device 10 of this embodiment, the spring accommodating portion 54 has an opening 56 at the end of the accommodating recess 55 in the first direction D1, and the wall surface 57 has a bottom wall portion 57C that is continuous with the first wall surface portion 57A and the second wall surface portion 57B and contacts the end 25D2 of the pressure spring 25 in the second direction D2, and the second wall surface portion 57B is formed continuously from the opening 56 to the bottom wall portion 57C in the direction D. According to the above aspect, for example, when assembling the clutch center 40 and the pressure plate 70, the stress transmitted from the anti-rotation tool 150 to the second wall surface portion 57B can be dispersed, so that the second wall surface portion 57B can be further prevented from being damaged.

[0051] In the clutch device 10 of this embodiment, when viewed in the axial direction of the output shaft 15, the second wall surface portion 57B is located radially outward of a circle CL that is centered on the axis 15CL of the output shaft 15 and passes through the center 54CL of the spring accommodating portion 54. According to the above aspect, for example, when assembling the clutch center 40 and the pressure plate 70, co-rotation of the clutch center 40 and the pressure plate 70 with the output shaft 15 can be further suppressed.

[0052] In the clutch device 10 of this embodiment, the second wall surface portion 57B includes a left second wall surface portion 57BL located on the left side of a straight line SL passing through the axis 15CL of the output shaft 15 and the center 54CL of the spring accommodating portion 54, and a right second wall surface portion 57BR located on the right side of the straight line SL, when viewed from the axial direction of the output shaft 15. According to the above aspect, for example, the anti-rotation tool 150 can be attached to the left second wall surface portion 57BL and the right second wall surface portion 57BR, so that the co-rotation of the clutch center 40 and the pressure plate 70 with the output shaft 15 can be further suppressed.

[0053] In the clutch device 10 of this embodiment, the length of the second wall surface portion 57B in the direction D and the length of the circumferential direction S are formed to be a length that allows contact with the anti-rotation tool 150. According to the above aspect, for example, since the anti-rotation tool 150 can be more reliably contacted with the second wall surface portion 57B, co-rotation of the clutch center 40 and the pressure plate 70 with the output shaft 15 can be more reliably suppressed when the clutch center 40 and the pressure plate 70 are assembled.

[0054] In the clutch device 10 of this embodiment, the second wall surface portion 57B of the first spring accommodating portion 54A is located on the first circumferential direction S1 side of a first straight line SL1 passing through the axis 15CL of the output shaft 15 and the center 54ACL of the first spring accommodating portion 54A when viewed from the axial direction of the output shaft 15, and the second wall surface portion 57B of the second spring accommodating portion 54B is located on the second circumferential direction S2 side of a second straight line SL2 passing through the axis 15CL of the output shaft 15 and the center 54BCL of the second spring accommodating portion 54B when viewed from the axial direction of the output shaft 15. According to the above aspect, for example, when the clutch center 40 and the pressure plate 70 are assembled, it is possible to further suppress the clutch center 40 and the pressure plate 70 from rotating together with the output shaft 15.

[0055] In the clutch device 10 of this embodiment, the curvature of the second wall surface portion 57B is zero. According to the above aspect, for example, when the clutch center 40 and the pressure plate 70 are assembled, the second wall surface portion 57B of the spring accommodating portion 54 can be brought into surface contact with the anti-rotation tool 150, so that damage to the second wall surface portion 57B of the spring accommodating portion 54 by the anti-rotation tool 150 can be more reliably prevented.

[0056] In the clutch device 10 of this embodiment, the pressure plate 70 is provided with a pressure side cam portion 90 having a pressure side slipper cam surface 90S that separates the pressure plate 70 from the clutch center 40 in order to reduce the pressing force between the input side rotating plate 20 and the output side rotating plate 22 when it rotates relative to the clutch center 40, and the clutch center 40 is provided with a center side cam portion 60 having a center side slipper cam surface 60S that separates the pressure plate 70 from the clutch center 40 in order to reduce the pressing force between the input side rotating plate 20 and the output side rotating plate 22 when it rotates relative to the pressure plate 70. According to the above aspect, for example, when assembling the clutch center 40 and the pressure plate 70, if the clutch center 40 and the pressure plate 70 rotate together with the output shaft 15, the clutch center 40 and the pressure plate 70 will become separated and installation will become difficult. However, in the clutch device 10 of this embodiment, the rotation of the clutch center 40 and the pressure plate 70 together with the output shaft 15 can be further suppressed, making installation easy.

[0057] In the clutch device 10 of this embodiment, the pressure-side cam portion 90 has a pressure-side assist cam surface 90A that generates a force in a direction from the pressure plate 70 toward the clutch center 40 in order to increase the pressing force between the input side rotating plate 20 and the output side rotating plate 22 when it rotates relative to the clutch center 40, and the center-side cam portion 60 has a center-side assist cam surface 60A that generates a force in a direction that moves the pressure plate 70 closer to the clutch center 40 in order to increase the pressing force between the input side rotating plate 20 and the output side rotating plate 22 when it rotates relative to the pressure plate 70. According to the above aspect, the pressing force between the input side rotating plate 20 and the output side rotating plate 22 can be further increased.

[0058] 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.

[0059] In the embodiment described above, the pressure plate 70 is provided with the boss portion 84, and the clutch center 40 is provided with the spring accommodating portion 54, but this is not limited to the above. For example, as shown in FIG. 11 , the pressure plate 70 may be provided with the spring accommodating portion 54, and the clutch center 40 may be provided with the boss portion 84. In this case, the clutch center 40 is located between the clutch housing 30 and the pressure plate 70.

[0060] 11, the pressure plate 70 has a spring accommodating portion 54. The spring accommodating portion 54 is formed in the main body 72 in which the pressure-side cam portion 90 is formed. The spring accommodating portion 54 is formed so as to be recessed in the second direction D2 from the rear surface 72R of the main body 72. The spring accommodating portions 54 are disposed at equal intervals in the circumferential direction S of the pressure plate 70.

[0061] 11, the clutch center 40 has a plurality of boss portions 84 (three in this embodiment). The plurality of boss portions 84 are disposed at equal intervals in the circumferential direction S. The boss portions 84 are provided on the main body 42. The boss portions 84 are inserted into the pressure-side cam hole 73H. The pressure-side cam hole 73H is an example of a through hole.

[0062] In each of the above-described embodiments, the center side cam portion 60 has a center side assist cam surface 60A and a center side slipper cam surface 60S, but it may have only one of them or neither.

[0063] In each of the above-described embodiments, the pressure side cam portion 90 has a pressure side assist cam surface 90A and a pressure side slipper cam surface 90S, but it may have only one of them or neither. [Explanation of symbols]

[0064] 10 Clutch device 15 Output shaft 20 Input side rotating plate 22 Output side rotating plate 25 Pressure Spring 30 Clutch housing 40 Clutch center 43H Center side cam hole (through hole) 54 Spring housing 55 Recessed portion 56 Aperture 57 Wall 57A 1st wall section 57B 2nd wall section 57C Bottom wall 60 Center side cam part 60A Center side assist cam surface 60S Center side slipper cam surface 70 Pressure Plate 84 Boss 90 Pressure side cam part 90A Pressure side assist cam surface 90S Pressure side slipper cam surface 150 Anti-rotation tool

Claims

1. A clutch device that transmits or cuts off the rotational driving force of an input shaft to an output shaft, a clutch center that is accommodated in a clutch housing that holds a plurality of input side rotary plates that are rotationally driven by the rotational drive of the input shaft, and that is rotationally driven together with the output shaft; a pressure plate that is provided so as to be capable of approaching or separating from the clutch center and rotatable relative to the clutch center, and that is capable of pressing the input side rotating plate and a plurality of output side rotating plates that are arranged alternately with the input side rotating plate, When the direction in which the pressure plate moves is defined as a moving direction, the direction from one side of the moving direction to the other side is defined as a first direction, and the direction from the other side of the moving direction to one side is defined as a second direction, One of the pressure plate and the clutch center includes a boss portion extending in a first direction, the other of the pressure plate and the clutch center includes a through hole formed in the moving direction and into which the boss portion is inserted, and a spring accommodating portion that accommodates a pressure spring that urges the pressure plate in a direction toward the clutch center with respect to the moving direction, the spring accommodating portion includes an accommodating recess formed to be recessed in the second direction and configured to accommodate the pressure spring, and a wall surface defining the accommodating recess, A clutch device, wherein the wall surface has a first wall surface portion having a first curvature when viewed in the axial direction of the output shaft, and a second wall surface portion having a second curvature smaller than the first curvature.

2. The spring accommodating portion has an opening at an end of the accommodating recess in the first direction, the wall surface includes a bottom wall portion that is continuous with the first wall portion and the second wall portion and that is in contact with an end portion of the pressure spring in the second direction, The clutch device according to claim 1 , wherein the second wall portion is formed continuously from the opening to the bottom wall portion in the moving direction.

3. 3. The clutch device according to claim 1, wherein, when viewed in the axial direction of the output shaft, the second wall surface portion is located radially outward of a circle centered on the axis of the output shaft and passing through the center of the spring accommodating portion.

4. 3. The clutch device according to claim 1, wherein the second wall portion, when viewed in the axial direction of the output shaft, comprises a left second wall portion located to the left of a straight line passing through the axis of the output shaft and the center of the spring accommodating portion, and a right second wall portion located to the right of the straight line.

5. 3. The clutch device according to claim 1, wherein the second wall portion is formed to have a length that allows an anti-rotation tool to come into contact with the second wall portion.

6. a first circumferential direction is a direction from one side to the other side with respect to a circumferential direction of the pressure plate, and a second circumferential direction is a direction from the other side to the one side, the pressure plate being configured to rotate in the first circumferential direction, The spring accommodating portion includes a first spring accommodating portion and a second spring accommodating portion arranged in a circumferential direction, The first spring housing portion is located on the first circumferential direction side relative to the second spring housing portion, When viewed in the axial direction of the output shaft, the second wall surface portion of the first spring accommodating portion is located on the first circumferential direction side of a first straight line passing through an axis of the output shaft and a center of the first spring accommodating portion, 3. The clutch device according to claim 1, wherein the second wall surface portion of the second spring accommodating portion is located on the second circumferential side of a second straight line passing through the axial center of the output shaft and the center of the second spring accommodating portion when viewed from the axial direction of the output shaft.

7. 3. The clutch device according to claim 1, wherein the second wall portion has a curvature of zero.

8. the pressure plate includes 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 a pressing force between the input side rotating plate and the output side rotating plate when the pressure plate rotates relative to the clutch center; 3. The clutch device according to claim 1, wherein 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 input side rotating plate and the output side rotating plate when the clutch center rotates relative to the pressure plate.

9. the pressure-side cam portion has a pressure-side assist cam surface that generates a force in a direction from the pressure plate toward the clutch center in order to increase a pressing force between the input-side rotating plate and the output-side rotating plate when the pressure-side cam portion rotates relative to the clutch center, 9. The clutch device according to claim 8, wherein the center side cam portion has a center side assist cam surface that generates a force in a direction that brings the pressure plate closer to the clutch center in order to increase a pressing force between the input side rotating plate and the output side rotating plate when the center side cam portion rotates relative to the pressure plate.

10. The boss portion is provided on the pressure plate, 3. The clutch device according to claim 1, wherein the spring housing portion is provided in the clutch center.

11. The boss portion is provided on the clutch center, 3. The clutch device according to claim 1, wherein the spring housing portion is provided on the pressure plate.

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