JP2009063023A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device in which the strength of a cam for assisting pressure contact or a back torque limiter cam can be improved while achieving weight reduction. <P>SOLUTION: The power transmission device has a clutch housing 2, a clutch member 4, a pressure member 5, and a cam for assisting pressure contact or a back torque limiter cam. The power transmission device interrupts torque inputted to an input member or transmits the torque to an output member by separation or pressure contact between driving clutch plates 6 and driven clutch plates 7. The cam for assisting pressure contact or the back torque limiter cam is obtained by press-molding each of metallic members fixed to the clutch member 4 side and the pressure member 5 side respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission device that can arbitrarily transmit or block the rotational force of an input member to an output member.

  In general, a power transmission device included in a motorcycle is used to arbitrarily transmit or cut off the driving force of an engine to and from a driving wheel. An input member connected to the engine side, and the transmission and driving wheel side And an output member connected to the output member, and a clutch member connected to the output member. The transmission of the power is cut off by releasing the pressure contact force.

However, a pressure assist function that improves the pressure contact force of both clutch plates during power transmission, and a back torque limiter that separates both clutch plates when a so-called back torque is generated when the rotation of the output member exceeds the rotation speed of the input member. In order to add a function, for example, as disclosed in Patent Document 1, a cam is disclosed. According to the power transmission device in this document, two cams are formed by forming a slope surface on each of the pressure plate and the clutch center, and at the time of normal power transmission, the drive side clutch is driven by one cam (pressure contact assist cam). The direction in which the pressure plate is moved in a direction in which the plate and the driven clutch plate are in strong pressure contact, and when the back torque is generated, the pressure contact between both clutch plates is released by the other cam (back torque limiter cam). The back plate can be absorbed by moving the pressure plate.
Japanese Patent Laid-Open No. 2-150517

  However, in the above-described conventional power transmission device, the pressure-assist assist cam and the back torque limiter cam are composed of the slope surfaces formed in part of the clutch member and the pressure member, so the clutch member and the pressure member are When formed of a molded product such as aluminum, the strength may be insufficient. In addition, it can be considered that the clutch member and the pressure member are formed of a high-rigidity material such as iron in order to avoid the insufficient strength, but in this case, the weight is increased and it is difficult to reduce the weight. is there.

  The present invention has been made in view of such circumstances, and provides a power transmission device that can reduce the weight and can improve the strength of a cam for pressure-contact assist or a cam for a back torque limiter. It is in.

  According to the first aspect of the present invention, there are provided a clutch housing that is rotated with the rotation of the input member to form a plurality of drive side clutch plates, and a plurality of driven side clutch plates that are alternately formed with the drive side clutch plates of the clutch housing. And a clutch member connected to the output member, and attached to the clutch member while being movable in the axial direction of the clutch member, and the driving-side clutch plate and the driven side as the clutch member moves in the axial direction. A pressure member capable of pressing or separating the clutch plate, and a pressure contact force between the drive side clutch plate and the driven side clutch plate when the rotational force input to the input member can be transmitted to the output member. When the rotation of the pressure assisting cam for increasing or the output member exceeds the rotational speed of the input member, the drive side clutch plate and the driven side clutch A back torque limiter cam for separating the clutch plate, and the rotational force input to the input member is transmitted to the output member by pressure contact or separation between the driving clutch plate and the driven clutch plate. Alternatively, in the power transmission device that can be shut off, the pressure-contact assist cam or the back torque limiter cam is obtained by press-molding metal members fixed to the clutch member side and the pressure member side, respectively. To do.

  According to a second aspect of the present invention, in the power transmission device according to the first aspect, the metal member is formed of an annular member, and a plurality of press moldings are performed at substantially equal intervals, and the press contact assist cam or the back torque limiter is used. A cam is constructed.

  According to a third aspect of the present invention, in the power transmission device according to the second aspect of the present invention, the metal member is formed with press-contact assist cams and back torque limiter cams alternately.

  According to a fourth aspect of the present invention, in the power transmission device according to any one of the first to third aspects, the metal member is an iron member.

  According to the first aspect of the present invention, the pressure-assist assist cam or the back torque limiter cam is obtained by press-molding the metal members fixed to the clutch member side and the pressure member side, respectively, so that the weight can be reduced. In addition, the strength of the pressure-contact assist cam or the back torque limiter cam can be improved.

  According to the second aspect of the present invention, the metal member is formed of an annular member, and a plurality of press moldings are formed at substantially equal intervals to form a press-contact assist cam or a back torque limiter cam. The action of the cam or the back torque limiter cam can be smoothly transmitted to the pressure member.

  According to the third aspect of the present invention, the metal member is formed with the pressing assist cam and the back torque limiter cam alternately. Therefore, the assist function by the pressing assist cam and the limiter by the back torque limiter cam are provided. It can combine functions.

  According to the invention of claim 4, since the metal member is made of an iron member, it is possible to further improve the strength of the pressure-assist assist cam or the back torque limiter cam while favorably performing press molding.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The power transmission device according to the first embodiment is disposed in a vehicle such as a two-wheeled vehicle and arbitrarily transmits or cuts off the driving force of the engine to the mission or driving wheel side, as shown in FIG. A clutch housing 2 in which a gear 1 as an input member is formed, a clutch member 4 connected to a shaft 3 as an output member, and a pressure member 5 attached to the right end side of the clutch member 4 in FIG. It mainly comprises a drive side clutch plate 6 connected to the clutch housing 2 side and a driven side clutch plate 7 connected to the clutch member 4 side.

  The gear 1 is rotatable about the shaft 3 when a driving force (rotational force) transmitted from the engine is input, and is connected to the clutch housing 2 by a rivet 8 or the like. The clutch housing 2 is formed of a cylindrical case member opened on the right end side of the figure, and a plurality of drive side clutch plates 6 are formed from the inner peripheral wall thereof. Each of the drive side clutch plates 6 is made of a plate material formed in a substantially annular shape, and is configured to rotate with the rotation of the clutch housing 2 and to slide in the axial direction (left-right direction in the figure). Yes.

  The clutch member 4 is formed of a cylindrical case member disposed in the clutch housing 2 and opened on the right end side in the figure. The shaft 3 is connected to the substantially center of the clutch member 4 by spline fitting while passing therethrough, and the shaft 3 is also rotated when the clutch member 4 rotates. Further, a spline extending in the axial direction (left and right direction in the figure) is formed on the outer peripheral side surface of the clutch member 4, and the driven side clutch plate 7 is fitted into the spline.

  More specifically, the spline formed on the clutch member 4 is formed in a concavo-convex shape that is integrally formed over substantially the entire circumference of the outer peripheral side surface thereof, and is formed on the driven side in the concave groove constituting the spline. Since the clutch plate 7 is fitted, the movement of the driven clutch plate 7 in the rotational direction is restricted while allowing the movement of the driven clutch plate 7 relative to the clutch member 4, and the clutch plate 4 can rotate together with the clutch member 4. is there.

  The driven clutch plates 7 are alternately stacked with the driving clutch plates 6 so that the adjacent clutch plates 6 and 7 can be pressed against or separated from each other. That is, both the clutch plates 6 and 7 are allowed to slide in the axial direction of the clutch member 4 and are pressed against each other when pressed by the pressure member 5 in the left direction in FIG. Is transmitted to the clutch member 4 and the shaft 3, and when the pressure member 5 releases the pressure, the clutch member 4 stops and stops following the rotation of the clutch housing 2, and transmits the rotational force to the shaft 3. Will not be done.

  The separation of the clutch plates 6 and 7 here does not have to be a state in which a clearance is generated between the clutch plates 6 and 7, and the pressure contact force is not required even if a physical clearance is not generated. It also includes a state where the clutch member 4 is released and does not follow the rotation of the clutch housing 2 (that is, a state where the drive side clutch plate 6 slides on the driven side clutch plate 7).

  The pressure member 5 is disposed at a position that closes the opening (right end in the figure) of the clutch member 4, and is always urged leftward by the disc spring S in the figure. On the other hand, the edge surface of the pressure member 5 is in contact with the drive side clutch plate 6 in the stacked state that is closest to the pressure member 5 (the rightmost portion in the figure), and is attached with a disc spring S. The pressure member 5 that has gained power presses the drive clutch plate 6 at the rightmost portion, so that the clutch plates 6 and 7 are brought into pressure contact with each other. Therefore, the clutch housing 2 and the clutch member 4 are always connected, and the shaft 3 can be rotated when a rotational force is input to the gear 1.

  However, a push rod 9 extending in the axial direction is disposed inside the shaft 3, and the push rod 9 protrudes to the right in the figure by operating an operating means (not shown). The pressure member 5 can be moved rightward against the biasing force of the disc spring S. When the pressure member 5 moves in the right direction, the pressure contact force between the driving side clutch plate 6 and the driven side clutch plate 7 is released, and the rotational force input to the gear 1 and the clutch housing 2 in the separated state is applied to the clutch member 4. And it is interrupted without being transmitted to the shaft 3. The pressure member 5 is configured such that the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed against or separated from each other as the clutch member 4 moves in the axial direction.

  Here, in this embodiment, iron members 10 and 11 (metal members) as annular members are fixed to the clutch member 4 side and the pressure member 5 side, respectively, in a state of facing each other. The iron members 10 and 11 are fixed to the clutch member 4 and the pressure member 5 by rivets 12 and 13 inserted through the through holes 10c and 11c, respectively, and operate integrally with the clutch member 4 and the pressure member 5. Configured to get.

  As shown in FIG. 2, these iron members 10 and 11 are provided with gradient portions 10a, 10b, 11a, and 11b obtained by press forming and bending, and the gradient portions 10a and 11a, and The iron members 10 and 11 are arranged to face each other so that the gradient portions 10b and 11b can come into contact with each other (see FIG. 3). In other words, the annular steel members 10 and 11 are press-formed (plastically deformed by bending) with a press machine to form the gradient portions 10a, 10b, 11a, and 11b.

  Thus, the gradient portions 10a and 11a are configured so that the driving side clutch plate 6 and the driven side clutch when the rotational force input to the gear 1 (input member) can be transmitted to the shaft 3 (output member). A cam for assisting press-contact for increasing the press-contact force with the plate 7 is configured, and the gradient portions 10b and 11b are such that the rotation of the shaft 3 (output member) exceeds the rotation speed of the gear 1 (input member). The back torque limiter cam is configured to cause the drive side clutch plate 6 and the driven side clutch plate 7 to be separated from each other.

  That is, when the rotational force input to the gear 1 and the clutch housing 2 can be transmitted to the shaft 3 via the clutch member 4, the rotational force in the direction A1 in FIG. Therefore, the pressure member 5 generates a force in the direction A2 in the drawing due to the action of the pressure-contact assist cam, so that the pressure-contact force between the drive side clutch plate 6 and the driven side clutch plate 7 is increased. It has become.

  On the other hand, when the rotation of the shaft 3 exceeds the rotation speed of the gear 1 and the clutch housing 2 and the back torque in the direction B1 in FIG. 5 is generated, the pressure member 5 is moved by the action of the back torque limiter cam. The drive side clutch plate 6 and the driven side clutch plate 7 are separated from each other by moving in the middle B2 direction. Thereby, the malfunction with respect to the power transmission device and power source (engine side) by back torque can be avoided.

  According to the power transmission device, the pressing assist cam or the back torque limiter cam is obtained by press-molding the iron members 10 and 11 (metal members) fixed to the clutch member 4 side and the pressure member 5 side, respectively. Therefore, the weight can be reduced, and the strength of the pressure-assist assist cam or the back torque limiter cam can be improved. Further, instead of the iron members 10 and 11, other metal members (at least a metal having higher rigidity than the clutch member 4 and the pressure member 5) may be used, but as long as they are made of iron members as in this embodiment, It is possible to further improve the strength of the press-contact assist cam or the back torque limiter cam while performing the press molding well.

  Furthermore, the iron members 10 and 11 (metal members) are formed of an annular member, and are press-molded at a substantially equal interval position (six locations in the present embodiment) so that a pressure contact assist cam and a back torque limiter cam are provided. Since it is configured, the action of the pressure contact assist cam or the back torque limiter cam can be smoothly transmitted to the pressure member 5. Furthermore, since the metal members 10 and 11 are alternately formed with the pressure contact assist cam and the back torque limiter cam, an assist function by the pressure contact assist cam and a limiter function by the back torque limiter cam are provided. Can be combined.

  Although the present embodiment has been described above, the present invention is not limited to this. For example, the fixing of the iron members 10 and 11 to the clutch member 4 and the pressure member 5 is not limited to the rivets 12 and 13. Other fixing methods (for example, fixing by insert molding or the like) may be employed. In the present embodiment, the pressure member 5 is biased by the disc spring S. However, a coil spring is disposed on a bolt (clutch bolt) inserted through the through holes 10c and 11c, and the coil spring is attached to the coil spring. Thus, the pressure member 5 may be biased.

  Furthermore, in this embodiment, the pressure contact assist cams or back torque limiter cams are alternately formed in the circumferential direction with respect to the iron members 10 and 11, but only the pressure contact assist cams or the back torque limiter cams are formed. A plurality may be formed in the circumferential direction. Furthermore, in this embodiment, three pressure-contact assist cams and three back torque limiter cams are formed on the iron members 10 and 11, but each of the cams is formed in other numbers. There may be. The power transmission device according to the present invention can be applied to various multi-plate clutch type power transmission devices such as two-wheeled vehicles, automobiles, three-wheel or four-wheel buggies, and general-purpose machines.

  The press-contact assist cam or the back torque limiter cam is a power transmission device obtained by press-molding metal members fixed to the clutch member side and the pressure member side, respectively, with other functions added, Alternatively, the present invention can be applied to those having different external shapes.

The longitudinal cross-sectional view which shows the power transmission device which concerns on embodiment of this invention A perspective view showing an iron member (clutch member side or pressure member side) in the power transmission device The perspective view which shows the state which has arrange | positioned the iron member in the power transmission device facing. Cross-sectional schematic diagram for illustrating the action of the pressure-contact assisting cam during forward rotation of the clutch member in the power transmission device Sectional schematic diagram for illustrating the operation of the back torque limiter cam during reverse rotation of the clutch member in the power transmission device (a state in which the back torque is applied).

Explanation of symbols

1 Gear (input member)
2 Clutch housing 3 Shaft (output member)
4 Clutch member 5 Pressure member 5b Insertion hole 6 Drive side clutch plate 7 Driven side clutch plate 8 Rivet 9 Push rod 10, 11 Iron member (metal member)
10a, 11a Gradient (Pressure assisting cam)
10b, 11b Gradient part (back torque limiter cam)
12, 13 Rivet S Belleville spring

Claims (4)

A clutch housing that rotates with the rotation of the input member to form a plurality of drive side clutch plates;
A clutch member having a plurality of driven-side clutch plates formed alternately with the drive-side clutch plates of the clutch housing, and connected to an output member;
A pressure member that is attached to the clutch member while being capable of moving in the axial direction of the clutch member, and capable of press-contacting or separating the driving-side clutch plate and the driven-side clutch plate along with the axial movement of the clutch member; ,
A pressure assisting cam for increasing the pressure contact force between the drive side clutch plate and the driven side clutch plate when the rotational force input to the input member can be transmitted to the output member; A back torque limiter cam for separating the drive side clutch plate and the driven side clutch plate when the rotation exceeds the rotation number of the input member;
In the power transmission device capable of transmitting or shutting off the rotational force input to the input member by the press contact or separation between the driving side clutch plate and the driven side clutch plate,
The pressure transmission assist cam or the back torque limiter cam is obtained by press-molding metal members fixed to the clutch member side and the pressure member side, respectively.   2. The power transmission device according to claim 1, wherein the metal member is formed of an annular member, and the press contact assist cam or the back torque limiter cam is configured by a plurality of press moldings at substantially equal positions. .   The power transmission device according to claim 2, wherein the metal member is formed with a cam for assisting a pressure contact and a cam for a back torque limiter alternately.   The power transmission device according to any one of claims 1 to 3, wherein the metal member is an iron member.

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