WO2018116638A1

WO2018116638A1 - Power transmission device

Info

Publication number: WO2018116638A1
Application number: PCT/JP2017/039034
Authority: WO
Inventors: 秀訓北澤; 修間野
Original assignee: 株式会社エクセディ
Priority date: 2016-12-20
Filing date: 2017-10-30
Publication date: 2018-06-28
Also published as: JP2018100699A; JP6892758B2

Abstract

Provided is a power transmission device in which a clutch is turned on by a centrifugal pressing mechanism, said device suppressing drag torque during a release operation. This device includes a clutch hub (3), a clutch center (4), a clutch part (5), a first pressure plate (6), a centrifugal pressing mechanism (7), and a release mechanism (8). The first pressure plate (6) is disposed axially outward of the clutch part (5), and has a pressing part that presses the clutch part (5). The centrifugal pressing mechanism (7) is disposed axially inward of the clutch part (5), and has a weight member (71). The movement of the weight member (71) presses the clutch part (5) against the first pressure plate (6). The weight member (71) applies a releasing force to the clutch center (4) so as to move the pressing part of the first pressure plate (6) axially outward, whereby the release mechanism (8) cuts off power transmission to the clutch part (5).

Description

Power transmission device

The present invention relates to a power transmission device, and more particularly to a power transmission device provided in a motorcycle.

Generally, a multi-plate clutch device is used as a power transmission device provided in a motorcycle or the like. The multi-plate clutch device includes a clutch housing connected to the crankshaft side of the engine, a clutch center connected to the transmission side, a clutch portion for transmitting and shutting power between them, and a clutch portion. And a pressure plate for pressing. The clutch portion has a first clutch plate that engages with the clutch housing and a second clutch plate that engages with the clutch center, and both clutch plates are alternately arranged in the axial direction.

Also, as a conventional power transmission device for a motorcycle, a multi-plate clutch device using a centrifugal force of a weight member as a centrifuge is also provided (Patent Document 1). In this power transmission device, a weight member is disposed in a groove formed inside the clutch housing. When the clutch housing rotates, the weight member accommodated therein receives a centrifugal force and moves radially outward along the groove and also moves in the axial direction. By the movement of the weight member in the axial direction, the pressure member is pressed in the axial direction via the first and second plate members and the coil spring, the plurality of clutch plates are pressed, and the clutch portion is turned on (power transmission state). Become.

International Publication 2013/183588

In the device of Patent Document 1, a release mechanism is provided on the opposite side of the weight member and the pressure member with the clutch portion interposed therebetween. When the clutch portion is turned off (power transmission is released), the pressure member is pressed toward the weight member by the release mechanism. Thereby, the pressing force of the pressure member against the clutch portion is released, and the clutch portion is turned off.

During the release operation as described above, when the pressure member is pressed toward the weight member, the first plate member receives a pressing force from the weight member toward the clutch portion, and the second plate member receives a pressing force in the reverse direction from the release mechanism. Will receive. And since the 1st board | plate material and the 2nd board | plate material are contact | abutted via the friction material, drag torque generate | occur | produces between a 1st board | plate material and a 2nd board | plate material at the time of release operation | movement. Since the second plate is engaged with the clutch center, the drag torque is transmitted to the transmission side via the clutch center. Then, torque acts on the dog clutch of the transmission, and it becomes difficult to release the engagement of the dog clutch.

An object of the present invention is to suppress the generation of drag torque during a release operation in a power transmission device that turns on a clutch portion by a pressing mechanism using a centrifuge.

(1) A power transmission device according to the present invention includes a clutch housing, an output member, a clutch portion, a first pressure member, a centrifugal pressing mechanism, and a release mechanism. The clutch housing is rotated by power from the engine. The output member is disposed on the inner peripheral portion of the clutch housing and outputs power to a member on the transmission side. The clutch portion transmits power between the clutch housing and the output member. A 1st pressure member is arrange | positioned at the 1st direction side of the axial direction of a clutch part, and has a press part which can press a clutch part. The centrifugal pressing mechanism is disposed on the second direction side in the axial direction of the clutch portion, has a centrifuge that can move in the radial direction and the axial direction by rotation of the clutch housing, and the first clutch portion is moved by the movement of the centrifuge. Press against the pressing part of the pressure member. The release mechanism moves the pressing portion of the first pressure member in the first direction by applying a release force to a portion other than the portion receiving the pressing force by the centrifuge, and releases the power transmission of the clutch portion.

In this device, when the rotation from the engine is transmitted and the clutch housing rotates, the rotation causes the centrifuge to move outward in the radial direction by the centrifugal force and also to move in the axial direction. By the movement of the centrifuge in the axial direction, the clutch portion is pressed toward the first pressure member, and the clutch portion is turned on.

On the other hand, at the time of release, the release mechanism moves the pressing portion of the first pressure member in the first direction away from the clutch. As a result, the clutch portion is turned off. At this time, the release force by the release mechanism acts on a portion other than the portion that receives the pressing force by the centrifuge. Therefore, the rotating member does not generate drag torque due to the pressing force and release force by the centrifuge. For this reason, the bad influence by drag torque like the conventional apparatus can be suppressed.

(2) Preferably, the centrifugal pressing mechanism further includes a second pressure member. A 2nd pressure member is arrange | positioned between the axial direction of a centrifuge and a clutch part, and presses a clutch part in a 1st direction by the movement of a centrifuge.

Here, the clutch portion is not pressed directly by the centrifuge, but the clutch portion is pressed via the second pressure member. For this reason, the pressing force by the centrifuge acts uniformly and stably on the clutch portion.

(3) Preferably, the release mechanism has a disk-shaped spring and a release plate. The disc-shaped spring has a pressing portion at the outer peripheral portion and a fulcrum portion at a radially intermediate portion. The release plate presses the inner peripheral portion of the disc-shaped spring toward the second direction, and moves the outer peripheral portion of the disc-shaped spring in the first direction with the fulcrum portion as a fulcrum.

Here, the clutch part is pressed using a disk-shaped spring. Further, during the release operation, the pressing force to the clutch portion can be released by the lever principle. Therefore, the structure of the release mechanism is simplified.

(4) Preferably, the fulcrum portion of the disc spring is supported by the output member. The output member is not subjected to a pressing force by the centrifuge. For this reason, even if the release force of the release mechanism acts on the output member, drag torque due to the pressing force of the centrifuge and the release force does not occur in the output member.

(5) Preferably, the clutch part has a first clutch plate that engages with the clutch housing and a second clutch plate that engages with the output member. And the output member has a clutch hub, a clutch center, and a torque transmission part. The clutch hub engages with the second clutch plate. The clutch center is connected to a member on the transmission side. The torque transmission unit transmits torque between the clutch hub and the clutch center.

Here, the output member is composed of a clutch hub that engages with the output portion of the clutch portion, and a clutch center that is connected to a member on the transmission side.

(6) Preferably, the torque transmission unit includes a reverse torque assist cam unit that applies a pressing force between the first clutch and the second clutch plate when torque is transmitted from the clutch center to the clutch hub.

Here, the torque transmission unit transmits the forward rotation torque from the clutch hub to the clutch center, that is, from the input side to the output side. On the other hand, when reverse torque is transmitted from the clutch center to the clutch hub, a pressing force is applied to the clutch portion by the reverse torque assist cam portion.

Therefore, at the time of starting, the rotation member on the transmission side can be rotated by a kick operation, and this rotation can be transmitted to the engine side via the clutch portion to start the engine.

(7) Preferably, the torque transmission unit further includes a positive torque assist cam unit that applies a pressing force between the first clutch and the second clutch plate when torque is transmitted from the clutch hub to the clutch center.

Here, the torque transmission unit transmits the forward rotation torque from the clutch hub to the clutch center, that is, from the input side to the output side. In addition to this, when the forward rotation torque is transmitted, the positive torque assist cam portion applies a pressing force to the clutch portion.

For this reason, when the clutch portion is constituted by a plurality of clutch plates, a necessary torque transmission capacity can be ensured with a small number of clutch plates.

In the present invention as described above, in the power transmission device that turns on the clutch portion by the pressing mechanism using the centrifuge, it is possible to suppress the generation of drag torque during the release operation.

1 is a cross-sectional view of a clutch device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a part of the clutch device of FIG. 1. The figure which extracted a part of FIG. The figure which extracted the other part of FIG. The plane schematic diagram of a cam part.

FIG. 1 is a cross-sectional view of a clutch device 1 for a motorcycle as an example of a power transmission device. In the following description, the “axial direction” refers to the left-right direction in FIG. 1 (the right direction is the “first direction”, the left direction is the “second direction”), and the “axial direction outside” (the first direction side). ) Indicates the right side of FIG. 1, and “inner side in the axial direction” (second direction side) indicates the left side of FIG.

This clutch device 1 is for transmitting the power from the crankshaft of the engine to the transmission and for canceling the power transmission state by operating the release mechanism. The clutch device 1 includes a clutch housing 2, a clutch hub 3 and a clutch center 4 that constitute an output member, a clutch portion 5, a first pressure plate 6 (first pressure member), a centrifugal pressing mechanism 7, and a release. And a mechanism 8. The clutch device 1 has a cam portion 9 (torque transmission portion) that transmits torque between the clutch hub 3 and the clutch center 4.

[Clutch housing 2]
The clutch housing 2 includes a disk portion 21 and a cylindrical portion 22 and is connected to the input gear 10. The input gear 10 meshes with a drive gear (not shown) on the engine side, and power (torque) generated by the engine (not shown) is input to the input gear 10.

The disc portion 21 is formed with a plurality of protrusions 21a protruding inward in the axial direction at predetermined intervals in the circumferential direction. The elastic member 11 is mounted on the outer periphery of the protruding portion 21 a, and torque from the input gear 10 is transmitted to the disc portion 21 via the elastic member 11. The clutch housing 2 and the input gear 10 are connected in the axial direction via a plate 12 and a rivet 13.

The cylindrical portion 22 is formed so as to extend outward from the outer peripheral edge of the disc portion 21 in the axial direction. A plurality of notches 22a extending in the axial direction are formed in the cylindrical portion 22 at predetermined intervals in the circumferential direction.

[Clutch hub 3]
The clutch hub 3 is disposed inside the clutch housing 2, specifically, on the inner peripheral side of the cylindrical portion 22. As shown in FIGS. 1 and 2, the clutch hub 3 is an annular member, and a plurality of engagement grooves 3a are formed on the outer peripheral surface. An engagement portion 3b that is annularly continuous is formed at the axially inner end of the engagement groove 3a. That is, the engagement groove 3a is open on the outer side in the axial direction, but is closed on the inner side in the axial direction. FIG. 2 is an exploded view showing a part of the clutch device 1.

[Clutch center 4]
The clutch center 4 is arranged on the inner peripheral side of the clutch housing 2 and further on the inner peripheral side of the clutch hub 3. The clutch center 4 has a boss portion 41, a tubular portion 42, and a connecting portion 43.

The boss portion 41 is formed in a cylindrical shape, and a spline hole 41a extending in the axial direction is formed on the inner peripheral surface. An input shaft (not shown) of the transmission is engaged with the spline hole 41a.

The cylindrical portion 42 is formed on the outer peripheral portion of the clutch center 4 and is disposed so that a part of the axial direction overlaps the inner peripheral surface of the clutch hub 3 in the axial direction. The cylindrical portion 42 includes a plurality of engaging grooves 42a, three support portions 42b, and six fixing portions 42c. The engagement groove 42 a is formed at the outer end of the cylindrical portion 42 in the axial direction. The three support portions 42b are formed so as to protrude further from the outer peripheral surface of the cylindrical portion 42 to the outer peripheral side, and are arranged at equal intervals in the circumferential direction. A support protrusion 42d that protrudes outward in the axial direction is formed on the support portion 42b. The fixed portion 42c is formed so as to protrude axially outward from the axially outer end surface of the cylindrical portion 42. A screw hole 42e is formed in the fixing portion 42c.

The connecting portion 43 is a portion that connects the boss portion 41 and the tubular portion 42. The connecting portion 43 is inclined so as to go outward in the axial direction from the inner peripheral side to the outer peripheral side.

A thrust plate 14 is provided between the axially inner end surface of the boss portion 41 and the central portion of the input gear 10.

[Clutch part 5]
The clutch unit 5 includes four first clutch plates 51 and three second clutch plates 52. Both the

clutch plates

51 and 52 are formed in an annular shape and are alternately arranged in the axial direction.

A plurality of engaging protrusions protruding outward are formed on the outer peripheral portion of the first clutch plate 51, and the engaging protrusions are engaged with notches 22 a formed in the cylindrical portion 22 of the clutch housing 2. . Accordingly, the first clutch plate 51 is movable in the axial direction with respect to the clutch housing 2 and is not relatively rotatable. The first clutch plate 51 has friction facings fixed on both sides.

The second clutch plate 52 is formed with a plurality of engaging protrusions that protrude toward the inner peripheral side at the inner peripheral end. The engaging protrusion is engaged with an engaging groove 3 a formed on the outer peripheral surface of the clutch hub 3. Therefore, the second clutch plate 52 is movable in the axial direction with respect to the clutch hub 3 and is not relatively rotatable.

[First pressure plate 6]
As shown in FIGS. 2 and 3, the first pressure plate 6 includes a main body portion 61 and a cylindrical portion 62.

The main body 61 is an annular member, and a pressing surface 61a is formed on the outer peripheral portion of the side surface on the inner side in the axial direction. The pressing surface 61 a contacts the first clutch plate 51. A plurality of engaging protrusions 61 b are formed on the inner peripheral end of the main body 61. The engagement protrusion 61 b is engaged with the engagement groove 42 a of the clutch center 4. Therefore, the pressure plate 6 is movable in the axial direction with respect to the clutch center 4 in a predetermined range (a range in which the engagement groove 42a is formed) in the axial direction, and is not rotatable. A support protrusion 61 c is formed on the outer peripheral portion of the side surface on the outer side in the axial direction of the main body 61.

The cylindrical portion 62 is formed to extend outward in the axial direction from the outer peripheral end portion of the main body portion 61. A plurality of engaging grooves 62 a are formed in the cylindrical portion 62.

[Centrifuge pressing mechanism 7]
As shown in FIG. 4, the centrifugal pressing mechanism 7 includes a weight member (centrifuge) 71, a second pressure plate 72 (second pressure member), and a pressing force adjustment mechanism 73.

A plurality of grooves 21b extending in the radial direction are formed in the disk portion 21 of the clutch housing 2, and the weight member 71 is movable in the radial direction along the grooves 21b. As shown in FIGS. 1 and 4, the bottom surface of the groove 21b is inclined so as to go outward in the axial direction as it goes outward in the radial direction. Accordingly, when the weight member 71 moves outward in the radial direction, the weight member 71 also moves outward in the axial direction.

The second pressure plate 72 is disposed between the weight member 71 and the clutch portion 5 (specifically, the first clutch plate 51) in the axial direction. As for the 2nd pressure plate 72, the press surface 72a is formed in the outer peripheral part, and the engaging part 72b is formed in the inner peripheral part in the side surface of the axial direction outer side. The pressing surface 72 a can contact the first clutch plate 51.

The pressing force adjusting mechanism 73 includes an engagement plate 73a, a plurality of springs 73b, a support plate 73c, and a plurality of bolts 73d.

The engaging plate 73a has an inner peripheral disc portion 73e, an outer peripheral disc portion 73f, and a cylindrical portion 73g. A plurality of holes are formed in the inner peripheral disk portion 73e, and the support protrusions 21c of the clutch housing 2 pass through the holes. The support protrusion 21 c is formed on the disc portion 21 of the clutch housing 2 so as to protrude outward in the axial direction. The outer peripheral disc portion 73 f is engaged with the engaging portion 72 b of the second pressure plate 72.

The plurality of springs 73b are mounted on the outer peripheral portion of the support protrusion 21c. One end of the spring 73b is supported by the inner peripheral disk portion 73e of the engagement plate 73a, and the other end is supported by the support plate 73c. The support plate 73c is fixed to the front end surface of the support protrusion 21c by a bolt 73d.

In such a configuration, the second pressure plate 72 is urged inward in the axial direction via the engagement plate 73a by the urging force of the spring 73b. That is, the second pressure plate 72 is urged in the direction opposite to the pressing force by the weight member 71 by the spring 73b. Therefore, by adjusting the urging force of the spring 73b, it is possible to adjust the pressing force applied to the clutch portion 5 by the weight member 71.

[Release mechanism 8]
As shown in FIG. 3, the release mechanism 8 includes a diaphragm spring 81, a full clam ring 82, and a release plate 83.

The diaphragm spring 81 includes an annular pressing portion 81a formed on the outer peripheral portion, a lever portion 81b including a plurality of levers formed on the inner peripheral portion, and a radial intermediate between the pressing portion 81a and the lever portion 81b. And a fulcrum part 81c formed in the part. The pressing portion 81 a is supported by the support protrusion 61 c of the first pressure plate 6 and can press the first pressure plate 6.

The full clam ring 82 is formed in an annular shape and is fixed to the fixing portion 42 c of the cylindrical portion 42 of the clutch center 4 by a bolt 85. A support protrusion 82 a that protrudes inward in the axial direction is formed on the outer periphery of the full clam ring 82. A fulcrum portion 81 c of the diaphragm spring 81 is supported between the support protrusion 82 a and the support protrusion 42 d of the clutch center 4. Further, at the inner peripheral end of the full clam ring 82, an engagement recess 82b that is recessed in an annular shape is formed on the inner surface in the axial direction.

The release plate 83 is formed in an annular shape and is disposed on the inner peripheral portion of the full clam ring 82. A pressing protrusion 83 a protruding in the axial direction is formed on the inner surface in the axial direction of the release plate 83. The pressing protrusion 83 a is in contact with the inner peripheral end portion of the lever portion 81 b of the diaphragm spring 81. Further, on the outer peripheral portion of the release plate 83, an engaging portion 83b that engages with the engaging recess 82b of the full clam ring 82 is formed, and a guide portion 83c that extends in the axial direction is further formed. The guide portion 83 c is movable in the axial direction along the inner peripheral surface of the full clam ring 82. A release bearing (not shown) is mounted on the release plate 83. At the time of release, the release plate 83 is moved inward in the axial direction via a bearing.

In the configuration as described above, when the release plate 83 moves inward in the axial direction, the inner peripheral end portion of the lever portion 81b of the diaphragm spring 81 moves inward in the axial direction, and the diaphragm spring 81 uses the fulcrum portion 81c as a fulcrum. 81a moves outward in the axial direction. That is, by the lever principle, the pressing portion 81a of the diaphragm spring 81 moves outward in the axial direction. Thereby, the pressing force to the clutch part 5 of the 1st pressure plate 6 is cancelled | released.

[Cam part 9]
The cam portion 9 transmits torque between the clutch hub 3 and the clutch center 4. 2 and 5, the cam portion 9 includes a plurality of (three in the present embodiment) first cam portions 91 provided in the clutch hub 3 and a plurality of cam portions 9 provided in the clutch center 4 (this embodiment). 3) in the form. FIG. 5 is a schematic plan view of the cam portion 9 (viewed from the outer peripheral side).

The first cam portion 91 is formed on the inner peripheral surface of the clutch hub 3 so as to protrude further to the inner peripheral side. The first cam portion 91 is formed with a cam recess 91a that is recessed toward the outer peripheral side. The cam recess 91a is opened inward in the axial direction, and a first cam surface 91b for transmitting positive torque and a second cam surface 91c for transmitting negative torque are formed on the outer side in the axial direction. Each of the cam surfaces 91b and 91c is inclined so as to be directed inward in the axial direction as the cam surfaces 91b and 91c are separated from the circumferential center of the cam recess 91a.

The second cam portion 92 is formed on the outer peripheral surface of the cylindrical portion 42 of the clutch center 4 so as to protrude further to the outer peripheral side. A third cam surface 92b for forward rotation torque transmission and a fourth cam surface 92c for reverse rotation torque transmission are formed on the axially outer surface of the second cam portion 92. The third cam surface 92b has the same inclination as the first cam surface 91b of the clutch hub 3, and both 91b and 92b are in contact with each other. The fourth cam surface 92c has the same inclination as the second cam surface 91c of the clutch hub 3, and both 91c and 92c are in contact with each other.

In such a cam portion 9, as shown in FIG. 5, when torque (forward rotation torque) is transmitted from the clutch hub 3 to the clutch center 4, the first cam surface 91b and the third cam surface 92b are pressed against each other. Then, the clutch hub 3 moves outward in the axial direction with respect to the clutch center 4. The engaging portion 3b formed on the outer peripheral surface of the clutch hub 3 is engaged with the second clutch plate 52 that is the innermost in the axial direction among the three second clutch plates 52. The clutch plate 51 and the second clutch plate 52 are pressed more firmly. That is, the first cam surface 91b and the third cam surface 92b constitute a forward rotation torque assist cam portion that generates an assist force for clutch-on when the forward rotation torque is transmitted.

Conversely, when torque in the same rotational direction (reverse torque) is transmitted from the clutch center 4 to the clutch hub 3, the second cam surface 91c and the fourth cam surface 92c are pressed against each other, and the clutch hub 3 Move outward in the axial direction. Therefore, similarly to the above, the engaging portion 3b of the clutch hub 3 moves the second clutch plate 52 outward in the axial direction, whereby the first clutch plate 51 and the second clutch plate 52 are pressed more firmly. Will be. That is, the second cam surface 91c and the fourth cam surface 92c constitute a reverse torque assist cam portion that generates an assist force for clutch-on when the reverse torque is transmitted.

Since the assist cam portion described above is formed with an inclined cam surface, when torque is transmitted between the clutch hub and the clutch center, the magnitude is in accordance with the magnitude of the transmitted torque. The pressing force can be applied to the clutch portion 5.

[Operation]
<Clutch on state>
When the rotation from the engine is input to the apparatus and the clutch release operation is not performed, the weight member 71 moves radially outward and axially outward by centrifugal force. For this reason, the pressing force of the weight member 71 outward in the axial direction is transmitted to the clutch portion 5 via the second pressure plate 72. On the other hand, the pressing force of the diaphragm spring 81 acts on the opposite side of the second pressure plate 72 across the clutch portion 5 via the first pressure plate 6, so that the clutch portion 5 has both

pressure plates

6, 72. Sandwiched between. Therefore, the clutch unit 5 is turned on (power transmission state).

In such a state, torque input from the engine via the input gear 10 and the elastic member 11 is transmitted to the first and second

clutch plates

51 and 52 via the clutch housing 2, and further, the clutch hub 3 and the clutch It is transmitted to the input shaft (not shown) of the transmission via the center 4.

Here, when torque (forward rotation torque) is transmitted from the clutch hub 3 to the clutch center 4, as described above, an assisting force for moving the clutch hub 3 outward in the axial direction is applied by the action of the cam portion 9. For this reason, the pressing force for clutch-on is further increased.

<Release operation>
On the other hand, when the release plate 83 is moved inward in the axial direction by the rider's operation, the outer peripheral portion (pressing portion 81a) of the diaphragm spring 81 is moved away from the first pressure plate 6 as described above. For this reason, the pressing force of the diaphragm spring 81 against the clutch portion 5 is released, and the pressing force by the weight member 71 is not transmitted to the clutch portion 5. Therefore, the clutch unit 5 is turned off (release of the power transmission state).

<Starting the engine>
In the motorcycle according to the present embodiment, the cell motor for starting the engine is not provided. Therefore, the engine is started by kicking the kick pedal.

When the transmission side member is rotated by a kick operation by the kick pedal, the rotation is transmitted from the clutch center 4 to the clutch hub 3. That is, contrary to the normal traveling, torque (reverse torque: the rotation direction is the same as the forward torque) acts from the clutch center 4 to the clutch hub 3. When reverse rotation torque acts on the cam portion 9, as described above, an assisting force that moves the clutch hub 3 outward in the axial direction acts, and the clutch portion 5 is turned on. Therefore, no pressing force is generated by the weight member 71 when the engine is started, but the torque from the transmission side is transmitted through the clutch center 4 → the clutch hub 3 → the clutch portion 5 → the clutch housing 2 → the input gear 10 →. It is transmitted to the member on the side, and the engine can be rotated.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and various changes or modifications can be made without departing from the scope of the present invention.

(A) In the above-described embodiment, the release force at the time of release is received by the clutch center 4. However, the member that receives the release force may be another member as long as the pressing force by the weight member 71 is not applied. Good.

(B) The configuration for transmitting the pressing force of the weight member to the clutch portion is not limited to the above embodiment. For example, the pressing force adjustment mechanism may be omitted.

(C) Although the diaphragm spring is used for the release mechanism, the release force may be applied to the first pressure plate by using the lever principle by using another lever member or the like.

(D) In the above embodiment, the cam portion is formed integrally with the clutch hub and the clutch center, but may be constituted by another member.

In the power transmission device of the present invention, it is possible to suppress the generation of drag torque during the release operation in a device that turns on the clutch portion by a pressing mechanism using a centrifuge.

1 Clutch device (power transmission device)
2 Clutch housing 3 Clutch hub 4 Clutch center

42b Support portion

42d Support protrusion 5 Clutch portion 51 First clutch plate 52 Second clutch plate 6 First pressure plate 7 Centrifugal pressing mechanism 71 Weight member (centrifugal)
72 Second pressure plate 8 Release mechanism 81 Diaphragm spring 83 Release plate 9 Cam part (torque transmission part)
91 1st cam part 92

2nd cam part

91b, 92b 1st cam surface, 3rd cam surface (forward rotation torque assist cam part)
91c, 92c 2nd cam surface, 4th cam surface (reverse rotation torque assist cam part)

Claims

A clutch housing that is rotated by power from the engine; an output member that is disposed on an inner peripheral portion of the clutch housing and outputs power to a member on the transmission side;
A clutch portion for transmitting power between the clutch housing and the output member;
A first pressure member disposed on a first direction side in the axial direction of the clutch portion and having a pressing portion capable of pressing the clutch portion;
A centrifuge arranged on a second axial side of the clutch portion and movable in a radial direction and an axial direction by rotation of the clutch housing; and the clutch portion is moved to the first pressure by the movement of the centrifuge. A centrifugal pressing mechanism that presses against the pressing portion of the member;
A release mechanism that moves the pressing portion of the first pressure member in the first direction by applying a release force to a portion other than the portion that receives the pressing force by the centrifuge, and releases the power transmission of the clutch portion;
Power transmission device with
The centrifugal pressing mechanism is
A second pressure member that is disposed between the centrifuge and the clutch portion in an axial direction and presses the clutch portion in the first direction by movement of the centrifuge;
The power transmission device according to claim 1.
The release mechanism is
A disc-shaped spring having the pressing portion on the outer peripheral portion and a fulcrum portion in the radial intermediate portion;
A release plate that presses an inner peripheral portion of the disc-shaped spring toward the second direction and moves the outer peripheral portion of the disc-shaped spring in the first direction with the fulcrum portion as a fulcrum;
Having
The power transmission device according to claim 1 or 2.
The power transmission device according to claim 3, wherein a fulcrum portion of the disc-shaped spring is supported by the output member.
The clutch part is
A first clutch plate engaged with the clutch housing;
A second clutch plate engaged with the output member;
Have
The output member is
A clutch hub with which the second clutch plate is engaged;
A clutch center coupled to the transmission side member;
A torque transmission part for transmitting torque between the clutch hub and the clutch center;
Having
The power transmission device according to any one of claims 1 to 4.
The torque transmission portion includes a reverse torque assist cam portion that applies a pressing force between the first clutch and the second clutch plate when torque is transmitted from the clutch center to the clutch hub. 5. The power transmission device according to 5.
The torque transmission portion further includes a forward rotation torque assist cam portion that applies a pressing force between the first clutch and the second clutch plate when torque is transmitted from the clutch hub to the clutch center. The power transmission device according to claim 5 or 6.