Provided are a wet friction plate configured so that drag torque can be reduced while a manufacturing burden is reduced with a simple configuration, a wet multiplate clutch device including the wet friction plates, and a wet friction plate manufacturing method. A wet friction plate (200) includes friction members (210) provided on a flat plate annular core metal (201), having oil grooves (203), and made of a paper material. The friction members (210) include higher friction members (211) and lower friction members (212). The higher friction member (211) is formed such that the height thereof from a surface of the core metal (201) is higher than that of the lower friction member (212). In addition, the higher friction member (211) is formed with a less-elastically-deformable structure than that of the lower friction member (212). The lower friction member (212) is formed such that the height thereof from the surface of the core metal (201) is lower than that of the higher friction member (211). In addition, the lower friction member (212) is formed with a more-elastically-deformable structure than that of the higher friction member (211). The higher friction members (211) and the lower friction members (212) are alternately arranged along a circumferential direction on the core metal (201).

A power transmission device has a clutch member, a pressure member 5, a weight member 8, an interlocking member 9 and a bearing holding member C coupled to an activation member 10. The bearing holder member C holds a bearing B1 interposed between the activation member 10 and the pressure member 5. The bearing holding member C has a cylindrical member with one open end. An open end portion Ca is fit into and attached to a recessed portion 4d formed in a first clutch member 4a.

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A clutch apparatus is provided which includes a center clutch and a pressure clutch that can hold a clutch plate without falling off of the clutch plate and also prevent a reduction in strength. A clutch apparatus 100 includes a center clutch 105 and a pressure clutch 112, which hold clutch plates 104 placed facing friction plates 103 that are rotationally driven by a driving shaft. The center clutch 105 includes a center-side mating portion 108 mating with internal teeth of the clutch plate 104. In addition, the center-side mating portion 108 includes a protruding tooth 110. The pressure clutch 112 includes a pressure-side mating portion 116 mating with internal teeth of the clutch plate 104. In addition, the pressure-side mating portion 116 includes a run-off 117. The protruding tooth 110 extends over the run-off 117 of the pressure-side mating portion 116, as one of spline teeth forming the center-side mating portion 108.

Provided is a clutch device configured so that different desired torque values can be set without influence between assist torque and slipper torque. A clutch device 100 includes a center clutch 105 holding clutch plates 104 arranged facing friction plates 103 to be rotatably driven by a drive shaft, and a pressure clutch 111. The center clutch 105 includes center-side assist cam surfaces 106a and center-side slipper cam surfaces 106b. The pressure clutch 111 includes pressure-side assist cam surfaces 112a and pressure-side slipper cam surfaces 112b. A contact surface between the center-side assist cam surface 106a and the pressure-side assist cam surface 112a and a contact surface between the center-side slipper cam surface 106b and the pressure-side slipper cam surface 112b are formed at different positions in a radial direction.

Provided is a clutch device configured so that different desired torque values can be set without influence between assist torque and slipper torque. A clutch device 100 includes a center clutch 105 holding clutch plates 104 arranged facing friction plates 103 to be rotatably driven by a drive shaft, and a pressure clutch 111. The center clutch 105 includes center-side assist cam surfaces 106a and center-side slipper cam surfaces 106b. The pressure clutch 111 includes pressure-side assist cam surfaces 112a and pressure-side slipper cam surfaces 112b. A contact surface between the center-side assist cam surface 106a and the pressure-side assist cam surface 112a and a contact surface between the center-side slipper cam surface 106b and the pressure-side slipper cam surface 112b are formed at different positions in a radial direction.

A clutch device includes a clutch center holding output-side rotating plates alternately arranged with input-side rotating plates, and a pressure plate movable toward or away from the clutch center. The pressure plate includes pressure-side fitting teeth holding the output-side rotating plates. The clutch center includes center-side fitting teeth holding the output-side rotating plates. In a half-clutch state, a portion of one of the center-side fitting teeth overlap with a portion of one of the pressure-side fitting teeth when seen in the radial directions of an output shaft.

A clutch device includes a clutch center holding output-side rotating plates alternately arranged with input-side rotating plates, and a pressure plate movable toward or away from the clutch center. The pressure plate includes pressure-side fitting teeth holding the output-side rotating plates. The clutch center includes center-side fitting teeth holding the output-side rotating plates. In a half-clutch state, a portion of one of the center-side fitting teeth overlap with a portion of one of the pressure-side fitting teeth when seen in the radial directions of an output shaft.

A multiple-disc friction clutch that has an excellent operability, enables smooth starting, and is easy to adjust in clutch capacity, is provided. A multiple-disc friction clutch includes clutch centers, which is a first clutch center and a second clutch center. The first clutch center is axially supported by an output rotation shaft in a relatively non-rotatable manner. The second clutch center is supported by the first clutch center in a relatively rotatable manner. Elastic members are interposed between the first clutch center and the second clutch center and are configured to be compressed and deformed by relative rotation of the first clutch center and the second clutch center so as to transmit power. The second clutch center has a side wall that faces a pressure plate and has an opening part that penetrates in an axial direction, at a position facing the elastic member of the side wall. A push rod is inserted and fitted in the opening part and is configured to be moved in the axial direction by compression deformation of the elastic member so as to press the pressure plate.