Power transmission device

Abstract

A power transmission device is provided that can avoid axial enlargement of the device and increase the clutch capacity. An auxiliary clutch plate (17) having a diameter different from that of a driving side clutch plate (6) and a driven side clutch plate (7) is arranged on a clutch housing (2). When the driving side clutch plate (6) and the driven side clutch plate (7) are pressed together, the auxiliary clutch plate (17) is pressed together to be in a state capable of transmitting the driving force of an engine (E) to a driving wheel (T). When the pressing force between the driving side clutch plate (6) and the driven side clutch plate (7) is released, the pressing force of the auxiliary clutch plate (17) is released, thereby cutting off the transmission of the driving force of the engine (E) to the driving wheel (T).

Description

TECHNICAL FIELD

[0001] The present application relates to a power transmission device capable of arbitrarily transmitting or cutting off transmission of a rotational force of an input member to an output member. BACKGROUND

[0002] Generally, a power transmission device provided in a two-wheeled motor vehicle for arbitrarily transmitting or cutting off transmission of a driving force of an engine to a transmission and drive wheels has an input member linked to the engine side, an output member linked to the transmission and drive wheels side, a clutch member linked to the output member, and a pressure member capable of approaching or departing from the clutch member, and is configured to transmit the power by causing the driving-side clutch plate and the driven-side clutch plate to be pressed and connected by causing the pressure member to approach the clutch member, and to cut off the transmission of the power by causing the pressing force of the driving-side clutch plate and the driven-side clutch plate to be released by causing the pressure member to depart from the clutch member.

[0003] As a conventional power transmission device, for example, as disclosed in Patent Literature 1, a centrifugal clutch unit provided with a counterweight member that is moved from an inner diameter side position to an outer diameter side position of a groove portion by centrifugal force accompanying rotation of a clutch housing, thereby being capable of causing the driving-side clutch plate and the driven-side clutch plate to be pressed and connected, has been proposed. According to this conventional power transmission device, the counterweight member is caused to be pressed and connected by centrifugal force by causing the clutch housing to rotate accompanying driving of the engine, thereby causing the driving-side clutch plate and the driven-side clutch plate to be pressed and connected to transmit the driving force of the engine to the wheels.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2013 / 183588 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, the above-described conventional power transmission device requires an increase in the number of the driving-side clutch plates and the driven-side clutch plates in order to achieve the clutch capacity required for a multi-plate clutch. In this case, if the driving-side clutch plates and the driven-side clutch plates are simply increased in the stacking direction of the multi-plate clutch, the device is likely to be large in the axial direction, which can exceed the settable space with respect to the vehicle. Note that this problem is not limited to the power transmission device provided with the counterweight member, and can occur in all power transmission devices of the multi-plate clutch type having the driving-side clutch plates and the driven-side clutch plates.

[0009] The present application has been made in view of such circumstances, and provides a power transmission device capable of avoiding a large increase in the axial direction of the device and increasing the capacity of a clutch.

[0010] Means for solving the problem

[0011] The invention described in Solution 1 is a power transmission device having: a clutch housing that rotates together with an input member that rotates by a driving force of an engine of a vehicle, and that is provided with a plurality of driving-side clutch plates; a clutch member that is provided with a plurality of driven-side clutch plates that are alternately formed with the driving-side clutch plates of the clutch housing, and that is linked to an output member that is capable of rotating a wheel of the vehicle; and a pressure member that is capable of moving between an operating position and a non-operating position, the operating position being a position in which the driving-side clutch plates and the driven-side clutch plates are pressed to be in a state in which the driving force of the engine is capable of being transmitted to the wheel, and the non-operating position being a position in which the pressing force of the driving-side clutch plates and the driven-side clutch plates is released to be capable of cutting off the transmission of the driving force of the engine to the wheel, the power transmission device being characterized in that an auxiliary clutch plate having a diameter different from that of the driving-side clutch plates and the driven-side clutch plates is provided to the clutch housing, the auxiliary clutch plate is pressed to be in a state in which the driving force of the engine is capable of being transmitted to the wheel at the time of pressing of the driving-side clutch plates and the driven-side clutch plates, and the pressing force of the auxiliary clutch plate is released to cut off the transmission of the driving force of the engine to the wheel at the time of release of the pressing force of the driving-side clutch plates and the driven-side clutch plates.

[0012] The invention described in Solution 2 is the power transmission device described in Solution 1, characterized by having a centrifugal clutch unit that has a counterweight member that is capable of moving from an inner diameter side position to an outer diameter side position by centrifugal force accompanying rotation of the clutch housing, that is capable of being in a state in which the driving-side clutch plates and the driven-side clutch plates are pressed and the auxiliary clutch plate is pressed to be in a state in which the driving force of the engine is capable of being transmitted to the wheel at the time when the counterweight member is in the outer diameter side position, and that is capable of releasing the pressing force of the auxiliary clutch plate to cut off the transmission of the driving force of the engine to the wheel at the time when the counterweight member is in the inner diameter side position.

[0013] The invention described in Aspect 3 is the power transmission device described in Aspect 2, characterized in that the centrifugal clutch unit is configured to have: a holding member that holds the weight member so as to be movable between the inner diameter side position and the outer diameter side position; a pressure contact member that moves toward the stacking direction of the drive side clutch plate and the driven side clutch plate by the movement of the weight member from the inner diameter side position toward the outer diameter side position, thereby causing the drive side clutch plate and the driven side clutch plate to be pressure contacted; and a force applying member that applies a force to the weight member from the outer diameter side position toward the inner diameter side position, one of the pressure contact member and the holding member causing the drive side clutch plate and the driven side clutch plate to be pressure contacted and the other of the pressure contact member and the holding member causing the auxiliary clutch plate to be pressure contacted when the weight member is in the outer diameter side position.

[0014] The invention described in Aspect 4 is the power transmission device described in any one of Aspects 1 to 3, characterized in that the stacking position of the drive side clutch plate and the driven side clutch plate and the auxiliary clutch plate are arranged so as to overlap in the axial direction of the clutch housing.

[0015] The invention described in Aspect 5 is the power transmission device described in any one of Aspects 1 to 4, characterized in that the auxiliary clutch plate is configured by a plurality of clutch plates.

[0016] Effects of the Invention

[0017] According to the invention of Aspect 1, since the auxiliary clutch plate having a diameter different from that of the drive side clutch plate and the driven side clutch plate is arranged in the clutch housing, the auxiliary clutch plate is caused to be pressure contacted at the time of pressure contact of the drive side clutch plate and the driven side clutch plate so as to be in a state in which the driving force of the engine is transmitted to the wheels, and the pressure contact of the auxiliary clutch plate is released at the time of release of the pressure contact of the drive side clutch plate and the driven side clutch plate so as to cut off the transmission of the driving force of the engine to the wheels, so it is possible to avoid the increase in size of the device in the axial direction and to increase the clutch capacity.

[0018] According to the invention of Aspect 2, since the centrifugal clutch unit is provided, the auxiliary clutch plate is caused to be pressure contacted at the same time as the pressure contact of the drive side clutch plate and the driven side clutch plate when the weight member is in the outer diameter side position so as to be in a state in which the driving force of the engine is transmitted to the wheels, and the pressure contact of the auxiliary clutch plate is released at the same time as the release of the pressure contact of the drive side clutch plate and the driven side clutch plate when the weight member is in the inner diameter side position so as to be able to cut off the transmission of the driving force of the engine to the wheels, so by the centrifugal clutch unit, in addition to the pressure contact or the release of the pressure contact of the drive side clutch plate and the driven side clutch plate, the pressure contact or the release of the pressure contact of the auxiliary clutch plate is also able to be performed.

[0019] According to the application of the aspect 3, since one of the pressure member and the holding member pressurizes the driving-side clutch plate and the passive-side clutch plate and the other of the pressure member and the holding member pressurizes the auxiliary clutch plate when the counterweight member is in the outer diameter side position, the pressurization or release of the pressurization force of the auxiliary clutch plate can be performed in addition to the pressurization or release of the pressurization force of the driving-side clutch plate and the passive-side clutch plate by the pressure member and the holding member constituting the centrifugal clutch unit.

[0020] According to the application of the aspect 4, since the laminated portions of the driving-side clutch plate and the passive-side clutch plate and the auxiliary clutch plate are arranged so as to overlap in the axial direction of the clutch housing, the device can be reliably prevented from being enlarged in the axial direction.

[0021] According to the application of the aspect 5, since the auxiliary clutch plate is constituted by a plurality of clutch plates, the clutch capacity of the auxiliary clutch plate can be arbitrarily increased. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an appearance view of a power transmission device according to an embodiment of the application.

[0023] Figure 2 is a cross-sectional view taken along line II-II in Figure 1

[0024] Figure 3 is a cross-sectional view taken along line III-III in Figure 1

[0025] Figure 4 is a perspective view of a clutch housing in a power transmission device according to an embodiment of the application.

[0026] Figure 5 is a three-view drawing of a first clutch member in a power transmission device according to an embodiment of the application.

[0027] Figure 6 is a perspective view of a first clutch member in a power transmission device according to an embodiment of the application.

[0028] Figure 7 is a three-view drawing of a second clutch member in a power transmission device according to an embodiment of the application.

[0029] Figure 8 is a perspective view of a second clutch member in a power transmission device according to an embodiment of the application.

[0030] Figure 9 is a three-view drawing of a pressure member in a power transmission device according to an embodiment of the application.

[0031] Figure 10 ​​is a perspective view showing a pressure member in a power transmission apparatus of an embodiment of the present application.

[0032] Figure 11 is a longitudinal sectional view showing a centrifugal clutch unit in a power transmission apparatus of an embodiment of the present application.

[0033] Figure 12 is a perspective view showing a centrifugal clutch unit in a power transmission apparatus of an embodiment of the present application, partially cut away.

[0034] Figure 13 is a three-view drawing showing a retaining member of a centrifugal clutch unit in a power transmission apparatus constituting an embodiment of the present application.

[0035] Figure 14 is a three-view drawing showing a support member of a centrifugal clutch unit in a power transmission apparatus constituting an embodiment of the present application.

[0036] Figure 15 is a three-view drawing showing a pressure contact member of a centrifugal clutch unit in a power transmission apparatus constituting an embodiment of the present application.

[0037] Figure 16 is a four-view drawing showing a counterweight member of a centrifugal clutch unit in a power transmission apparatus constituting an embodiment of the present application.

[0038] Figure 17 is Figure 16 is a sectional view taken along lines XVII-XVII in

[0039] Figure 18 is a plan view showing a state in which a counterweight member in a centrifugal clutch unit in a power transmission apparatus of an embodiment of the present application is in an inner diameter side position.

[0040] Figure 19 is a plan view showing a state in which a counterweight member in a centrifugal clutch unit in a power transmission apparatus of an embodiment of the present application is in an outer diameter side position.

[0041] Figure 20 is a schematic view for explaining (a) an action of a pressure contact assisting cam, (b) an action of a reverse torque limiter cam in a power transmission apparatus of an embodiment of the present application.

[0042] Figure 21 is a schematic view showing a vehicle to which a power transmission apparatus of an embodiment of the present application is applied.

[0043] Figure 22 is a sectional view showing a state in which a counterweight member in a power transmission apparatus of an embodiment of the present application is in an inner diameter side position.

[0044] Figure 23 is a cross-sectional view showing a state in which the counterweight member in the power transmission device of the embodiment of the present application is in an intermediate position between the inner diameter side position and the outer diameter side position.

[0045] Figure 24 is a cross-sectional view showing a state in which the counterweight member in the power transmission device of the embodiment of the present application is in the outer diameter side position.

[0046] Figure 25 is a cross-sectional view showing a state in which the counterweight member in the power transmission device of the embodiment of the present application is in the outer diameter side position and the pressure member is in the non-working position.

[0047] Figure 26 is a longitudinal cross-sectional view showing a power transmission device of another embodiment of the present application (the auxiliary clutch plate is composed of a plurality of clutch plates).

[0048] Figure 27 is a longitudinal cross-sectional view showing a power transmission device of another embodiment of the present application (the auxiliary clutch plate is composed of a plurality of clutch plates and overlaps the laminated portions of the drive side clutch plate and the driven side clutch plate).

[0049] Figure 28 is a longitudinal cross-sectional view showing a power transmission device of another embodiment of the present application (the auxiliary clutch plate is composed of a plurality of clutch plates and does not have a centrifugal clutch unit).

[0050] Figure 29 is a longitudinal cross-sectional view showing a power transmission device of another embodiment of the present application (the auxiliary clutch plate is composed of a plurality of clutch plates, overlaps the laminated portions of the drive side clutch plate and the driven side clutch plate, and does not have a centrifugal clutch unit).

[0051] Figure 30 is a longitudinal cross-sectional view showing a power transmission device of another embodiment of the present application (the auxiliary clutch plate is composed of a plurality of clutch plates, does not have a centrifugal clutch unit, and has a press contact auxiliary cam and a reverse torque limiter cam). DETAILED DESCRIPTION

[0052] Hereinafter, an embodiment of the present application will be specifically described with reference to the accompanying drawings. Figure 1

[0053] The power transmission device K of the present embodiment is provided in a vehicle as shown in FIG. 1 and is used to arbitrarily transmit or cut off the transmission of the driving force of an engine E to a drive wheel T side via a transmission M, as shown in FIG. 2. Figure 21 Figures 1 to 17 ​​As shown, it is configured to have a clutch housing 2 formed with an input gear 1 (input member) that rotates by the driving force of the engine E of the vehicle, an output shaft 3 (output member) connected to the transmission M, a clutch member (first clutch member 4a and second clutch member 4b), a pressure member 5, a plurality of driving side clutch plates 6 and a plurality of passive side clutch plates 7, a centrifugal clutch unit 9 provided with a counterweight member 10, and an auxiliary clutch plate 17.

[0054] The input gear 1 is able to rotate with the output shaft 3 as the center if it is input with the driving force (rotational force) transmitted from the engine E, and is linked with the clutch housing 2 by a rivet or the like. The clutch housing 2 is configured to be linked with the input gear 1 and is able to rotate with the rotation of the input gear 1 by the driving force of the engine E, and is configured as a cylindrical member that is open on the right end side and is open on the left end side. Figure 2 、 3 The clutch housing 2 is configured to be linked with the input gear 1 and is able to rotate with the rotation of the input gear 1 by the driving force of the engine E, and is configured as a cylindrical member that is open on the right end side and is open on the left end side.

[0055] In addition, as shown in Figure 4 , the clutch housing 2 is formed with a plurality of cutouts 2a on the entire circumference, and a plurality of driving side clutch plates 6 are installed in a manner fitted into these cutouts 2a. Each of the driving side clutch plates 6 is configured as a plate material formed in a substantially circular ring shape and rotates with the rotation of the clutch housing 2, and is configured to be able to slide in the axial direction (left-right direction). Figure 2 、 3 The driving side clutch plates 6 are configured to be able to slide in the axial direction (left-right direction) and are able to be pressed by the pressure member 5.

[0056] The clutch member (first clutch member 4a and second clutch member 4b) is installed with a plurality of passive side clutch plates 7 formed alternately with the driving side clutch plates 6 of the clutch housing 2, and is linked with the output shaft 3 (output member) that is able to rotate the drive wheels T via the transmission M of the vehicle, and is configured by assembling the two members of the first clutch member 4a and the second clutch member 4b.

[0057] The first clutch member 4a is configured to have a through hole (refer to Figure 5 、 6 ) formed in the center thereof through which the output shaft 3 is inserted and intermeshingly engages with the gear to be linked in the rotational direction. As shown in Figure 5 、 6 , a slope surface 4aa that constitutes a crimping assist cam and a slope surface 4ab that constitutes a reverse torque limiter cam are formed in the first clutch member 4a. Note that the reference numeral 4ac in the drawing indicates a protruding portion that is formed with a through hole for a bolt B that links the first clutch member 4a and the fixed member 8.

[0058] As shown in Figure 7 、 8As shown, the second clutch member 4b is formed of an annular member having a flange portion 4bb, and is configured to be mounted on the driven side clutch plate 7 by spline fitting at a spline fitting portion 4ba formed on the outer peripheral surface. Figure 2 、 3 As shown, a pressure member 5 is assembled to the clutch members (the first clutch member 4a and the second clutch member 4b), and a plurality of driving side clutch plates 6 and driven side clutch plates 7 are alternately installed in a stacked state between the flange portion 5c of the pressure member 5 and the flange portion 4bb of the second clutch member 4b.

[0059] like Figure 9 、 10 As shown, the pressure member 5 is composed of a circular plate-shaped member with a flange portion 5c formed throughout the peripheral portion, and can move between a working position and a non-working position. The working position is a position in which the driving side clutch plate 6 and the passive side clutch plate 7 are pressed together and set to a state in which the driving force of the engine E can be transmitted to the wheels. The non-working position is a position in which the pressing force between the driving side clutch plate 6 and the passive side clutch plate 7 is released and the transmission of the driving force of the engine E to the wheels can be cut off.

[0060] More specifically, if Figure 7 、 8 As shown, the splined fitting portion 4ba formed on the second clutch component 4b is composed of a concave and convex shape formed integrally over substantially the entire circumference of the outer peripheral side surface of the second clutch component 4b, and is constructed such that: the driven side clutch plate 7 is fitted into the groove constituting the splined fitting portion 4ba, while allowing the axial movement of the driven side clutch plate 7 relative to the second clutch component 4b while restricting the movement in the rotational direction, and can rotate together with the second clutch component 4b.

[0061] The driven-side clutch plates 7 and the driving-side clutch plates 6 are alternately stacked, and the adjacent clutch plates 6, 7 are capable of being pressed or releasing the pressing force. That is, the two clutch plates 6, 7 are allowed to slide axially toward the second clutch member 4b. The clutch is opened by the clutch plates (6a, 6b, 7a, 7b) being pressed, thereby achieving a state in which the rotational force of the clutch housing 2 is transmitted to the output shaft 3 via the second clutch member 4b and the first clutch member 4a. The clutch is closed by releasing the pressing force of the clutch plates (6a, 6b, 7a, 7b), thereby preventing the first clutch member 4a and the second clutch member 4b from following the rotation of the clutch housing 2, and transmission of the rotational force to the output shaft 3 is no longer possible.

[0062] Thus, in a state in which the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed, a rotational force (driving force of the engine E) input to the clutch housing 2 is transmitted to the drive wheel side (transmission M) via the output shaft 3 (output member), and in a state in which the pressing of the driving-side clutch plate 6 and the driven-side clutch plate 7 is released, the transmission of the rotational force (driving force of the engine E) input to the clutch housing 2 to the output shaft 3 (output member) can be cut off.

[0063] Further, as shown in Figure 9 , 10 , the pressure member 5 is formed with a plurality of (three in the present embodiment) insertion holes 5d over the circumference, and the clutch spring S is inserted into each of the insertion holes 5d. As shown in Figure 2 , the clutch spring S is housed in the insertion hole 5d and abuts against the fixed member 8 at one end, and is urged in a direction in which the driving-side clutch plate 6 and the driven-side clutch plate 7 are pressed. Further, by operating a clutch operation unit not shown, the pressing of the driving-side clutch plate 6 and the driven-side clutch plate 7 or the release of the pressing can be performed.

[0064] Further, in the present embodiment, as shown in Figure 5 , 6 , 9, 10, a slope surface 4aa and a slope surface 4ab are formed in the first clutch member 4a, and slope surfaces 5a and 5b opposed to these slope surfaces 4aa and 4ab are formed in the pressure member 5. That is, the slope surface 4aa and the slope surface 5a abut to constitute a pressing-assist cam, and the slope surface 4ab and the slope surface 5b abut to constitute a reverse torque limiter cam.

[0065] Further, when the rotational speed of the engine E rises to a state in which a rotational force input to the input gear 1 and the clutch housing 2 can be transmitted to the output shaft 3 via the first clutch member 4a and the second clutch member 4b (the weight member 10 is at the outer diameter side position), as shown in Figure 20 (a), a rotational force in the a direction is applied to the pressure member 5, and thus, by the action of the pressing-assist cam, a force in the c direction in the figure is generated in the pressure member 5. Thus, the pressure member 5 moves in a direction in which the flange portion 5c thereof further approaches the flange portion 4bb of the second clutch member 4b (left side in the figure), and the pressing force of the driving-side clutch plate 6 and the driven-side clutch plate 7 is increased. Figure 2 , 3

[0066] On the other hand, when a reverse torque is generated in which the rotation of the output shaft 3 exceeds the rotational speed of the input gear 1 and the clutch housing 2, as shown in Figure 20 ​As shown in (b), a rotational force in the direction b is applied to the clutch member 4. Consequently, the action of the counter-torque limiter cam causes the pressure member 5 to move in the direction d in the figure, releasing the contact force between the driving-side clutch plate 6 and the driven-side clutch plate 7. This prevents adverse effects on the power transmission device K and the power source (engine E side) caused by counter-torque.

[0067] like Figures 11 to 19 As shown, the centrifugal clutch unit 9 has a structure capable of being moved from an inner diameter side position (see FIG. Figure 18 ) to the outer diameter side (refer to Figure 19 ) is constructed as follows: when the weight component 10 is in the outer diameter side position, the driving side clutch plate 6 and the passive side clutch plate 7 are pressed together to set the driving force of the engine E to the wheel (driving wheel T), and when the weight component 10 is in the inner diameter side position, the pressing force between the driving side clutch plate 6 and the passive side clutch plate 7 is released to cut off the transmission of the driving force of the engine E to the wheel (driving wheel T).

[0068] Specifically, the centrifugal clutch unit 9 comprises a weight member 10 formed from a shogi piece-shaped (block-like) member, a retaining member 11 to which a support member 13 is attached, a pressure member 12, a first spherical member 14, a second spherical member 15, and an urging member 16 formed from a coil spring. It should be noted that the retaining member 11 and the pressure member 12 are formed with multiple protrusions along their circumferences and, like the drive-side clutch plate 6, are fitted into the notch 2a of the clutch housing 2. This allows the retaining member 11 and the pressure member 12 to move axially in the clutch housing 2 and to engage in the rotational direction, rotating with the clutch housing 2.

[0069] like Figure 16 As shown, the weight member 10 is composed of a shogi piece-shaped member having one surface X and another surface Y. Figure 17 As shown, the weight member 10 is configured to have a through hole 10a formed from one surface X to the other surface Y, an insertion portion 10b formed on the other surface Y, and a groove 10c formed on one surface X. Figure 18 、 19 As shown, the weight member 10 is housed in the housing portion 11a of the holding member 11 and is held at the inner diameter side position (see FIG. Figure 18 ), and, by being applied with centrifugal force, it moves outward against the force of the urging member 16 and reaches the outer diameter side position (refer to Figure 19 ).

[0070] The holding member 11 holds the weight member 10 so as to be movable between the inner diameter side position and the outer diameter side position, as shown in Figure 13 The holding member 11 is formed of a circular ring member, and is configured to have a plurality of accommodation portions 11a in which the weight member 10 is accommodated, formed over the entire circumference, a groove shape 11b formed in the accommodation portion 11a, and a pressing surface 11c. Each of the accommodation portions 11a is formed of a concave shape that matches the shape and the range of movement of the weight member 10, and is configured so that one end of the urging member 16 can abut against an inner peripheral wall surface 11aa thereof.

[0071] In addition, a support member 13 is fixed to the surface of the holding member 11 on which the accommodation portion 11a is formed. As shown in Figure 14 The support member 13 is formed of a holding portion 13a formed in the radial direction, and the weight member 10 is held to the holding member 11 by the holding portion 13a matching the groove 10c of the weight member 10. That is, the weight member 10 is formed with the groove 10c at the center position of one surface X thereof in the direction from the inner diameter side position to the outer diameter side position, and the weight member 10 is held so as to be movable in the radial direction (in the direction from the inner diameter side position to the outer diameter side position) by the holding portion 13a matching the groove 10c.

[0072] The pressing member 12 moves in the stacking direction (the right side in the middle) of the driving side clutch plate 6 and the driven side clutch plate 7 by the weight member 10 moving from the inner diameter side position to the outer diameter side position, thereby pressing the driving side clutch plate 6 and the driven side clutch plate 7. Specifically, as shown in Figure 2 3 The pressing member 12 is formed of a circular ring member, and is configured to have a plurality of slope grooves 12a formed over the entire circumference, a groove shape 12b formed at each of the positions where the slope grooves 12a are formed, and a pressing surface 12c. Figure 15

[0073] The slope grooves 12a are formed at positions corresponding to the weight member 10, and are formed so as to be upward slopes from the inner side to the outer side. Thus, in a state in which the clutch housing 2 is stopped, the weight member 10 is held to the inner diameter side position by the urging force of the urging member 16, and if the clutch housing 2 rotates, centrifugal force is applied to the weight member 10, and the weight member 10 moves along the slope grooves 12a of the upward slopes, and thus the pressing member 12 moves in a direction away from the holding member 11 (i.e., in a direction in which the driving side clutch plate 6 and the driven side clutch plate 7 are pressed).

[0074] Thus, if the holding member 11 and the pressing member 12 are assembled while the weight member 10 is in the middle, as shown in Figure 11 12 ​​​As shown, the gradient groove 12a is located at a position corresponding to each weight member 10, and the weight member 10 moves from the inner diameter side position to the outer diameter side position and along the gradient groove 12a by centrifugal force, and the pressing member 12 moves to the outer diameter side position. Figure 11 The pressing surface 12c formed on the pressing member 12 presses the driving side clutch plate 6 and the driven side clutch plate 7 to be in a pressing state, and the holding member 11 moves toward the driven side clutch plate 6 and the driven side clutch plate 7 by its reaction force. Figure 11 The auxiliary clutch plate 17 is pressed against the pressing surface 11 c formed on the holding member 11 by the holding member 11 .

[0075] like Figure 18 、 19 As shown, the weight member 10 of this embodiment is respectively accommodated in a plurality of accommodating portions 11a formed along the circumference of the holding member 11 and can move in the radial direction, and the urging member 16 is disposed on the inner peripheral wall surface 11aa of the accommodating portion 11a (see Figure 13 ) and the weight member 10 are arranged in a plurality of circumferential directions (two in each case in this embodiment) to bias the weight member 10 from the outer diameter side toward the inner diameter side. Here, the inner peripheral wall surface 11aa of the housing portion 11a is formed as a flat surface that abuts one end of the biasing member 16, enabling the biasing member 16 to be mounted in a stable state.

[0076] In addition, the weight member 10 of this embodiment is formed so that the surface ( Figure 17 The other surface Y in the through hole 10b is open and allows the biasing member 16 to be inserted and installed. Furthermore, the weight member 10, with the biasing member 16 inserted into the through hole 10b, is accommodated in the housing portion 11a of the retaining member 11. The biasing member 16 is installed so that it is located between the inner circumferential wall surface 11aa of the housing portion 11a and the weight member 10. It should be noted that the biasing member 16 is arranged so that one end abuts the inner circumferential wall surface 11aa and the other end abuts the end wall surface 10ba of the through hole 10b, thereby being able to bias the weight member 10 from the outer diameter side toward the inner diameter side.

[0077] The first spherical member 14 is composed of a steel ball mounted on the weight member 10. Figure 16 、 17 As shown, a portion of the spherical member 15 is protruded from an opening 10aa (a small diameter opening on the side of one surface X) formed in the through hole 10a of the weight member 10, and can roll in contact with the rolling surface of the pressing member 12. In addition, the second spherical member 15 is composed of a steel ball mounted on the weight member 10, as shown in FIG. Figure 16 、 17As shown, a part of the first spherical member 14 protrudes from the other opening 10ab (the large-diameter opening on the other face Y side) of the through-hole 10a of the weight member 10, and is able to roll in contact with the rolling surface of the holding member 11.

[0078] As shown, Figure 17 the through-hole 10a of the present embodiment is formed in a tapered shape in which the diameter continuously increases from the one opening 10aa (the small-diameter opening on the one face X side) to the other opening 10ab (the large-diameter opening on the other face Y side), and the first spherical member 14 is prevented from coming off from the outer peripheral edge portion of the small-diameter opening (in the present embodiment, the one opening 10aa on the one face X side) of the one opening 10aa and the other opening 10ab. That is, the first spherical member 14 and the second spherical member 15 of the present embodiment are composed of spherical members (the second spherical member 15 is a member having a larger diameter than the first spherical member 14) having mutually different diameters in accordance with the inner diameter of the through-hole 10a, and are able to roll in a state in which the small-diameter first spherical member 14 is prevented from coming off from the opening edge portion of the small-diameter side of the through-hole 10a and is in contact with the inner peripheral surface of the through-hole 10a, respectively.

[0079] On the other hand, as shown, Figure 11 , 12 the second spherical member 15 is prevented from coming off from the rolling surface of the holding member 11. Thereby, the small-diameter first spherical member 14 is prevented from coming off from the opening edge portion of the small-diameter side of the through-hole 10a, and the large-diameter second spherical member 15 is prevented from coming off from the rolling surface of the holding member 11 in a state in which a part protrudes from the large-diameter side opening of the through-hole 10a. Note that in the present embodiment, the large-diameter second spherical member 15 is assembled in a manner in which it opposes the rolling surface of the holding member 11, but the second spherical member 15 can also be assembled in a manner in which it opposes the rolling surface of the press-contact member 12. In this case, the small-diameter first spherical member 14 is prevented from coming off from the opening edge portion of the small-diameter side of the through-hole 10a, and the large-diameter second spherical member 15 is prevented from coming off from the rolling surface of the press-contact member 12 in a state in which a part protrudes from the large-diameter side opening of the through-hole 10a.

[0080] As shown, Figure 13 the rolling surface of the holding member 11 (in the present embodiment, the rolling surface of the second spherical member 15) is composed of a groove shape 11b along the moving direction of the weight member 10 (the direction connecting the inner-diameter side position and the outer-diameter side position), and as shown, Figure 15 the rolling surface of the press-contact member 12 (in the present embodiment, the rolling surface of the first spherical member 14) is composed of a groove shape 12b along the moving direction of the weight member 10 (the direction connecting the inner-diameter side position and the outer-diameter side position).

[0081] Furthermore, as shown, Figure 16 , 18As shown in Figures 1 and 19, the first spherical member 14 and the second spherical member 15 of the present embodiment are respectively formed in a plurality (in the present embodiment, two first spherical members 14 and two second spherical members 15 are respectively formed) throughout the circumference of the retaining member 11 (the width direction of the counterweight member 10). As the counterweight member 10 moves, the first spherical member 14 and the second spherical member 15 are respectively able to roll in the through hole 10a while moving along the groove shapes 11b and 12b.

[0082] The auxiliary clutch plate 17 is arranged in the clutch housing 2 and is composed of an annular member having a diameter different from that of the driving side clutch plate 6 and the driven side clutch plate 7 (in this embodiment, a smaller diameter than the driving side clutch plate 6 and the driven side clutch plate 7). Figure 2 、 3 As shown, the output shaft 3 (output member) is inserted into the central opening 17 a and is put into a fitted state. The output shaft 3 is also configured to have a pressed surface 17 b facing the pressing surface 11 c of the holding member 11 .

[0083] When the weight member 10 is in the outer diameter side position (i.e., when the driving side clutch plate 6 and the driven side clutch plate 7 are in a press-contact state), the auxiliary clutch plate 17 is pressed and contacted by the pressing surface 11 c formed on the retaining member 11, thereby enabling the driving force of the engine E to be transmitted to the output shaft 3. Furthermore, when the weight member 10 is in the inner diameter side position (i.e., when the press-contact force between the driving side clutch plate 6 and the driven side clutch plate 7 is released), the pressing force formed on the pressing surface 11 c of the retaining member 11 decreases, thereby releasing the press-contact force, thereby interrupting the transmission of the driving force of the engine E to the output shaft 3.

[0084] That is, when the weight member 10 moves toward the outer diameter side, the slope groove 12a functions as a cam, causing the retaining member 11 and the pressing member 12 to move away from each other. As a result, the pressing surface 12c of the pressing member 12 presses the driving clutch plate 6 and the driven clutch plate 7 together, and the pressing surface 11c of the retaining member 11 presses the pressed surface 17b of the auxiliary clutch plate 17 together, thereby transmitting the driving force of the engine E to the drive wheels T.

[0085] Moreover, if Figure 5 、 6 As shown, the first clutch member 4a of this embodiment has an abutment surface 4ad formed on a portion of the surface facing the pressure member 5, and as shown in FIG. Figure 9 、 10 As shown, the pressure member 5 has an abutment surface 5e formed on a portion of the surface facing the first clutch member 4a. When the first clutch member 4a, the second clutch member 4b and the pressure member 5 are assembled (in a state where no torque is transmitted from the input gear 1 (input member) to the output shaft 3 (output member)), as shown in FIG.Figure 2 、 3 is shown, the abutting surface 4ad of the first clutch member 4a and the abutting surface 5e of the pressure member 5 are in abutting contact.

[0086] Thus, in the state where the abutting surface 4ad and the abutting surface 5e are in abutting contact, during the process in which the weight member 10 of the centrifugal clutch unit 9 moves from the inner diameter side position (refer to Figure 22 ) to the intermediate position (refer to Figure 23 ) and the transmission torque from the input gear 1 (input member) to the output shaft 3 (output member) increases, the relative movement between the first clutch member 4a and the pressure member 5 is not allowed, and thus the operation of the press-contact assisting cam is limited.

[0087] After that, if the weight member 10 of the centrifugal clutch unit 9 further moves from the intermediate position (refer to Figure 23 ) toward the outer diameter side position (refer to Figure 24 ), the driven side clutch plate 7 and the driving side clutch plate 6 are pressed and contacted by the flange portion 4bb of the second clutch member 4b, and the pressing force of the flange portion 4bb becomes equal to or greater than the force of the clutch spring S, the second clutch member 4b and the pressure member 5 are moved in the axial direction (right direction) with respect to the first clutch member 4a, and the abutting surface 4ad of the first clutch member 4a and the abutting surface 5e of the pressure member 5 are separated. Note that Figure 2 , 3 is shown, the weight member 10 is in the outer diameter side position and the pressure member 5 is in the non-operating position (clutch closed state). Figure 25

[0088] Thus, in the state where the abutting surface 4ad and the abutting surface 5e are separated, during the process in which the weight member 10 of the centrifugal clutch unit 9 moves from the inner diameter side position to the outer diameter side position and the transmission torque from the input gear 1 (input member) to the output shaft 3 (output member) increases, the relative movement between the first clutch member 4a and the pressure member 5 is allowed, and thus the operation of the press-contact assisting cam is allowed.

[0089] That is, according to the present embodiment, the configuration is such that the auxiliary clutch plate 17 is pressed and contacted to be in a state in which the driving force of the engine E can be transmitted to the wheels (drive wheels T) at the time of press-contact of the driving side clutch plate 6 and the driven side clutch plate 7, and the press-contact force of the auxiliary clutch plate 17 is released to cut off the transmission of the driving force of the engine E to the wheels (drive wheels T) at the time of release of the press-contact force of the driving side clutch plate 6 and the driven side clutch plate 7.

[0090] ​More specifically, in the present embodiment, the centrifugal clutch unit 9 provided with the counterweight member 10 is configured to be in a state in which the driving force of the engine E is transmitted to the wheels (drive wheels T) when the counterweight member 10 is in the outer diameter side position and the auxiliary clutch plate 17 is pressed while the pressing of the driving side clutch plate 6 and the driven side clutch plate 7 is released when the counterweight member 10 is in the inner diameter side position.

[0091] In particular, in the present embodiment, when the counterweight member 10 is in the outer diameter side position, the pressing member 12 and the holding member 11 are moved in directions away from each other, and the pressing member 12 presses the driving side clutch plate 6 and the driven side clutch plate 7, and the holding member 11 presses the auxiliary clutch plate 17. Note that the centrifugal clutch unit 9 can be configured such that, when the counterweight member 10 is in the outer diameter side position, the pressing member 12 and the holding member 11 are moved in directions away from each other, and the holding member 11 presses the driving side clutch plate 6 and the driven side clutch plate 7, and the pressing member 12 presses the auxiliary clutch plate 17.

[0092] According to the present embodiment, the auxiliary clutch plate 17 having a diameter different from those of the driving side clutch plate 6 and the driven side clutch plate 7 is provided in the clutch housing 2, and the auxiliary clutch plate 17 is pressed when the driving side clutch plate 6 and the driven side clutch plate 7 are pressed to be in a state in which the driving force of the engine E is transmitted to the wheels (drive wheels T), and the pressing of the auxiliary clutch plate 17 is released when the pressing of the driving side clutch plate 6 and the driven side clutch plate 7 is released to cut off the transmission of the driving force of the engine E to the wheels (drive wheels T), and thus the device can be prevented from being enlarged in the axial direction and the clutch capacity can be increased.

[0093] In particular, the auxiliary clutch plate 17 of the present embodiment is provided in the clutch housing 2 at a position closer to the inner diameter side than the laminated portions (multi-plate clutch portions) of the driving side clutch plate 6 and the driven side clutch plate 7, and thus the device can be prevented from being enlarged in a direction orthogonal to the axial direction in addition to the axial direction and the clutch capacity can be increased, and the space on the inner diameter side in the clutch housing 2 can be effectively utilized.

[0094] Further, according to the present embodiment, the centrifugal clutch unit 9 is provided to press the auxiliary clutch plate 17 while pressing the driving-side clutch plate 6 and the driven-side clutch plate 7 when the counterweight member 10 is in the outer diameter side position, and to release the pressing force of the auxiliary clutch plate 17 while releasing the pressing force of the driving-side clutch plate 6 and the driven-side clutch plate 7 when the counterweight member 10 is in the inner diameter side position, so that the centrifugal clutch unit 9 is capable of performing the pressing or the release of the pressing force of the auxiliary clutch plate 17 in addition to the pressing or the release of the pressing force of the driving-side clutch plate 6 and the driven-side clutch plate 7.

[0095] Further, when the counterweight member 10 is in the outer diameter side position, one of the pressing member 12 and the retaining member 11 presses the driving-side clutch plate 6 and the driven-side clutch plate 7, and the other of the pressing member 12 and the retaining member 11 presses the auxiliary clutch plate 17, so that the pressing member 12 and the retaining member 11 of the centrifugal clutch unit 9 are capable of performing the pressing or the release of the pressing force of the auxiliary clutch plate 17 in addition to the pressing or the release of the pressing force of the driving-side clutch plate 6 and the driven-side clutch plate 7.

[0096] According to the power transmission device K of the present embodiment, the through-hole 10a of the counterweight member 10 in the centrifugal clutch unit 9 is tapered from the one opening 10aa to the other opening 10ab, and the first ball-shaped member 14 is prevented from coming off by the outer peripheral edge portion of the smaller diameter opening of the one opening 10aa and the other opening 10ab, so that the first ball-shaped member 14 can be easily and correctly installed in the counterweight member 10, and the manufacturing cost can be reduced.

[0097] Further, the first ball-shaped member 14 and the second ball-shaped member 15 are constituted by ball-shaped members having different diameters from the inner diameter of the through-hole 10a, and are capable of rolling in contact with the inner peripheral surface of the through-hole 10a, respectively, so that the first ball-shaped member 14 and the second ball-shaped member 15 can be stably rolled when the counterweight member 10 moves, and smooth movement can be achieved. Further, the second ball-shaped member 15 of the present embodiment is prevented from coming off by the rolling surface of the retaining member 11 or the pressing member 12, so that the first ball-shaped member 14 and the second ball-shaped member 15 can be easily prevented from coming off by assembling the retaining member 11 and the pressing member 12.

[0098] Further, the rolling surfaces of the retaining member 11 or the press-contact member 12 are constituted by groove shapes (11b, 12b) along the moving direction of the weight member 10, so that the second ball-shaped members 15 on the large-diameter side and the first ball-shaped members 14 on the small-diameter side can be reliably prevented from coming off, respectively, and smoother movement of the weight member 10 can be sought.

[0099] In addition to this, the weight member 10 of the present embodiment is housed in the accommodation portions 11a formed in plurality over the circumferential direction of the retaining member 11 and is movable in the radial direction, and the urging members 16 are respectively provided in plurality in the circumferential direction between the inner peripheral wall surfaces 11aa of the accommodation portions 11a and the weight member 10 and urge the weight member 10 from the position on the outer diameter side toward the position on the inner diameter side, so that the weight member 10 can be highly accurately urged from the position on the outer diameter side toward the position on the inner diameter side, and can be stably moved in accordance with the centrifugal force.

[0100] In addition, the weight member 10 of the present embodiment is formed with the insertion portion 10b that opens the surface opposed to the retaining member 11 and through which the urging member 16 is inserted and installed, so that the assembly of the urging member 16 with respect to the weight member 10 can be easily performed. Further, the weight member 10 of the present embodiment is formed with the groove 10c in the direction from the position on the inner diameter side toward the position on the outer diameter side, and the retaining member 11 (specifically, the support member 13 fixed to the retaining member 11 and integrated therewith) is formed with the retaining portion 13a that matches with the groove 10c and retains the weight member 10, so that the movement of the weight member 10 can be stably performed.

[0101] Further, the centrifugal clutch unit 9 of the present embodiment is constituted to have the first ball-shaped member 14 that protrudes a part from the opening 10aa of one of the through holes 10a formed in the weight member 10 and can roll in contact with the rolling surface (groove shape 11b) of the retaining member 11, and the second ball-shaped member 15 that protrudes a part from the opening 10ab of the other of the through holes 10a formed in the weight member 10 and can roll in contact with the rolling surface (groove shape 12b) of the press-contact member 12, so that the movement of the weight member 10 can be more stably performed.

[0102] In particular, the retaining member 11 or the press-contact member 12 has the groove shape (11b, 12b) along the moving direction of the weight member 10, which is set as the rolling surface of the first ball-shaped member 14 or the second ball-shaped member 15, so that the movement of the weight member 10 can be more smoothly performed. Further, the first ball-shaped member 14 and the second ball-shaped member 15 of the present embodiment are formed in plurality over the circumferential direction (width direction of the weight member 10) of the retaining member 11, respectively, so that the movement of the weight member 10 can be further stably sought.

[0103] The above describes the embodiment, but the present application is not limited to this, and for example, it can be as shown in Figure 26 As shown, the auxiliary clutch plate 17 is composed of a plurality of clutch plates. In this case, in addition to the auxiliary clutch plate 17 linked to the output shaft 3, a first auxiliary clutch plate 17c and a second auxiliary clutch plate 17d are provided to constitute a multi-plate clutch, and if the counterweight member 10 of the centrifugal clutch unit 9 moves to the outer diameter side position and the holding member 11 moves, the second clutch plate 17d is pressed by the pressing surface 11c of the holding member 11 to press the auxiliary clutch plate 17, the first auxiliary clutch plate 17c and the second auxiliary clutch plate 17d, and is set to a state in which the driving force of the engine E can be transmitted to the wheels (drive wheels T). In this way, if the auxiliary clutch plate 17 is composed of a plurality of clutch plates, the clutch capacity of the auxiliary clutch plate 17 (the multi-plate clutch including the first auxiliary clutch plate 17c and the second auxiliary clutch plate 17d) can be arbitrarily increased.

[0104] In addition, it can also be as shown in Figure 27 As shown, the auxiliary clutch plate 17 is composed of a plurality of clutch plates (a multi-plate clutch including the first auxiliary clutch plate 17c and the second auxiliary clutch plate 17d), and the laminated portions of the driving side clutch plate 6 and the driven side clutch plate 7 overlap in the axial direction X of the clutch housing 2. In this way, by overlapping the laminated portions of the driving side clutch plate 6 and the driven side clutch plate 7 and the auxiliary clutch plate 17 in the axial direction X of the clutch housing 2, the device can be reliably prevented from being enlarged in the axial direction X.

[0105] Furthermore, it can also be as shown in Figure 28 As shown, the auxiliary clutch plate 17 is composed of a plurality of clutch plates, and instead of the centrifugal clutch unit, has a linkage member 18, or as shown in Figure 29 As shown, the auxiliary clutch plate 17 is composed of a plurality of clutch plates, and overlaps the laminated portions of the driving side clutch plate 6 and the driven side clutch plate 7, instead of the centrifugal clutch unit, has a linkage member 18, or as shown in Figure 30 As shown, the auxiliary clutch plate 17 is composed of a plurality of clutch plates, instead of the centrifugal clutch unit, has a linkage member 18, and has a press-fitting auxiliary cam and a reverse torque limiter cam. Note that the linkage member 18 moves to the side of the auxiliary clutch plate 17 by the pressing force when the pressure member 5 operates and the driving side clutch plate 6 and the driven side clutch plate 7 are pressed, thereby pressing the auxiliary clutch plate 17.

[0106] In the present embodiment, the second ball member 15 is prevented from coming off by the rolling surface (groove shape 11a) of the holding member 11 (or the press contact member 12), but can be prevented from coming off by other prevention units and methods such as riveting. Also, in the present embodiment, in a state where the first clutch member 4a, the second clutch member 4b, and the pressure member 5 are assembled (a state where the transmission torque from the input gear 1 (input member) to the output shaft 3 (output member) is not transmitted), a state where the abutting surface 4ad and the abutting surface 5e are in abutment is provided, but a state where these abutting surfaces 4ad and 5e are apart can also be provided. Note that the power transmission device of the present application can be applied to various multi-plate clutch type power transmission devices other than two-wheeled motor vehicles, such as automobiles, three- or four-wheeled off-road vehicles, or general-purpose machines.

[0107] Industrial applicability

[0108] As long as a power transmission device in which an auxiliary clutch plate having a different diameter from the drive side clutch plate and the driven side clutch plate is provided to a clutch housing, the auxiliary clutch plate is pressed to be in a state where the driving force of the engine is transmitted to the wheels at the time of pressing of the drive side clutch plate and the driven side clutch plate, and the pressing force of the auxiliary clutch plate is released to cut off the transmission of the driving force of the engine to the wheels at the time of release of the pressing force of the drive side clutch plate and the driven side clutch plate is provided, the power transmission device can be applied to a power transmission device having a different appearance shape or to which other functions are added, and the like.

[0109] Explanation of reference numerals

[0110] 1 input gear (input member)

[0111] 2 clutch housing

[0112] 2a cutout

[0113] 3 output shaft (output member)

[0114] 4a first clutch member

[0115] 4aa slope surface (press contact auxiliary cam)

[0116] 4ab slope surface (reverse torque limiter cam)

[0117] 4ac protrusion

[0118] 4ad abutting surface

[0119] 4b second clutch member

[0120] 4ba spline fitting portion

[0121] 4bb flange portion

[0122] 5 pressure member

[0123] 5a slope surface (cam for crimping assistance)

[0124] 5b slope surface (cam for reverse torque limiter)

[0125] 5c flange portion

[0126] 5d insertion hole

[0127] 5e abutting surface

[0128] 6 drive side clutch plate

[0129] 7 driven side clutch plate

[0130] 8 fixing member

[0131] 9 centrifugal clutch unit

[0132] 10 counterweight member

[0133] 10a through hole

[0134] 10b insertion portion

[0135] 10aa one-side opening

[0136] 10ab other-side opening

[0137] 10ba end wall surface

[0138] 10c slot

[0139] 11 holding member

[0140] 11a housing portion

[0141] 11aa inner peripheral wall surface

[0142] 11b slot shape

[0143] 11c pressing surface

[0144] 12 crimping member

[0145] 12a slope slot

[0146] 12b slot shape

[0147] 12c pressing surface

[0148] 13 support member

[0149] 13a holding portion

[0150] 14 first ball member

[0151] 15 second ball member

[0152] 16 force applying member

[0153] 17 auxiliary clutch plate

[0154] 17a central opening

[0155] 17b pressed surface

[0156] 17c first auxiliary clutch plate

[0157] 17d second auxiliary clutch plate

[0158] 18 linkage member

[0159] S clutch spring

Claims

1. A power transmission device comprising: a clutch member housed in a clutch housing that rotates together with an input member rotated by the driving force of a vehicle engine and to which a plurality of driving-side clutch plates are mounted, the clutch member having a splined fitting portion formed on an outer peripheral surface thereof for fitting with the inner peripheral edges of a plurality of driven-side clutch plates formed alternately with the driving-side clutch plates, and connected to an output member capable of rotating the wheels of the vehicle; and The pressure member is movable between an operating position and a non-operating position, wherein the operating position is a position in which the driving side clutch plate and the driven side clutch plate are pressed together to be in a state in which the driving force of the engine can be transmitted to the wheels, and the non-operating position is a position in which the pressing force between the driving side clutch plate and the driven side clutch plate is released to cut off the transmission of the driving force of the engine to the wheels. The power transmission device is characterized in that: An auxiliary clutch plate having a diameter smaller than the diameter of the inner peripheral edge of the driven side clutch plate is disposed on the output member. When the driving side clutch plate and the driven side clutch plate are pressed together, the auxiliary clutch plate is pressed together to be in a state capable of transmitting the driving force of the engine to the wheels, and when the pressing force between the driving side clutch plate and the driven side clutch plate is released, the pressing force of the auxiliary clutch plate is released to cut off the transmission of the driving force of the engine to the wheels.

2. The power transmission device according to claim 1, characterized in that: The centrifugal clutch unit comprises a weight member that can be moved from an inner diameter side position to an outer diameter side position by the centrifugal force accompanying the rotation of the clutch housing, and when the weight member is in the outer diameter side position, the driving side clutch plate and the driven side clutch plate are pressed together and the auxiliary clutch plate is pressed together to set the driving force of the engine to the wheel. When the weight member is in the inner diameter side position, the pressing force of the driving side clutch plate and the driven side clutch plate is released and the pressing force of the auxiliary clutch plate is released to cut off the transmission of the driving force of the engine to the wheel.

3. The power transmission device according to claim 2, characterized in that: The centrifugal clutch unit is configured to include: a holding member that holds the weight member so as to be movable between the inner diameter side position and the outer diameter side position; a pressing member that moves in a stacking direction of the driving side clutch plate and the driven side clutch plate by the weight member moving from the inner diameter side position to the outer diameter side position, thereby pressing the driving side clutch plate and the driven side clutch plate into contact with each other; and a force applying member for applying force to the weight member from the outer diameter side position toward the inner diameter side position, When the weight member is at the outer diameter side position, one of the pressing member and the holding member presses the driving side clutch plate and the driven side clutch plate, and the other presses the auxiliary clutch plate.

4. The power transmission device according to any one of claims 1 to 3, characterized in that: The stacked portion of the driving-side clutch plates and the driven-side clutch plates and the auxiliary clutch plates are arranged so as not to overlap with each other in the axial direction of the clutch housing.

5. The power transmission device according to any one of claims 1 to 3, characterized in that: The auxiliary clutch plate is composed of a plurality of clutch plates.

6. The power transmission device according to any one of claims 1 to 3, The auxiliary clutch plate is arranged adjacent to one side surface of the clutch member in the axial direction. A groove portion extending in a radial direction of the output member is formed on one axial surface of the clutch member.

7. A power transmission device comprising: a clutch member housed in a clutch housing that rotates together with an input member rotated by a driving force of a vehicle engine and to which a plurality of driving-side clutch plates are mounted, a plurality of driven-side clutch plates mounted alternately with the driving-side clutch plates, and connected to an output member capable of rotating the wheels of the vehicle; a pressure member movable between an operating position and a non-operating position, wherein the operating position is a position in which the driving side clutch plate and the driven side clutch plate are pressed into contact with each other to enable transmission of the driving force of the engine to the wheels, and the non-operating position is a position in which the pressing force between the driving side clutch plate and the driven side clutch plate is released to cut off transmission of the driving force of the engine to the wheels; An auxiliary clutch plate having a diameter different from that of the driving-side clutch plate and the driven-side clutch plate is provided on the output member; and The centrifugal clutch unit includes a weight member that can be moved from an inner diameter side position to an outer diameter side position by centrifugal force accompanying the rotation of the clutch housing. in, The power transmission device is configured as follows: When the weight member is in the outer diameter side position, the driving side clutch plate and the driven side clutch plate are pressed together and the auxiliary clutch plate is pressed together to set the driving force of the engine to the wheel. When the weight member is in the inner diameter side position, the pressing force of the driving side clutch plate and the driven side clutch plate is released and the pressing force of the auxiliary clutch plate is released to cut off the transmission of the driving force of the engine to the wheel.

8. The power transmission device according to claim 7, A spline fitting portion is formed on the outer peripheral surface of the clutch member, into which the inner peripheral edge of the driven side clutch plate fits. The auxiliary clutch plate has a diameter smaller than a diameter of an inner peripheral edge of the driven-side clutch plate.

9. The power transmission device according to claim 7 or 8, The auxiliary clutch plate overlaps with at least a portion of the centrifugal clutch unit when viewed in a radial direction of the output member.

Images