JP4662896B2 - Multi-plate clutch - Google Patents

Description

  The present invention relates to a multi-plate clutch provided with a friction plate pressure contact force assist mechanism and a back torque limiter mechanism. The friction plate pressure contact force assist mechanism increases the clutch capacity by increasing the friction plate pressure contact force when the drive torque increases, and the back torque limiter mechanism reduces the back torque transmitted from the wheels. This mechanism relaxes the force and allows sliding between the friction plates. In the following description, a cam used for the back torque limiter mechanism is called a slipper cam, which means a cam that enables sliding between friction plates.

  As a prior art, a multi-plate clutch having both functions of an assist function and a back torque limiter function is known (see, for example, Patent Documents 1 and 2). However, since the assist function and the back torque limiter function are operated by the same cam in the above prior art, there is a limitation on independently optimizing the assist function and the back torque limiter function. In addition, it is necessary to provide clearance on each cam plate for dust prevention, wear, thermal expansion, etc. of the friction plate, and during the transition from one to the other of the assist function and the back torque limiter function, the lash (non-reactive state) ) Occurred.

JP 2005-172045 A JP 2005-325993 A

  The present invention seeks to provide a multi-plate clutch capable of independently optimizing the assist function and the back torque limiter function.

  The present invention solves the above-mentioned problems, and the invention according to claim 1 is a clutch outer that is rotationally driven from a drive shaft, a clutch inner that is connected to a driven shaft, and a relatively non-rotatable relative to the clutch outer. A plurality of drive friction plates engaged so as to be movable in the axial direction; a plurality of driven friction plates which are engaged with the clutch inner so as not to rotate relative to the clutch inner and are movable in the axial direction; In a multi-plate clutch having a resilient member that presses the friction plate group in the axial direction and frictionally engages the clutch outer and the clutch inner, the driven shaft is disposed so as not to be relatively rotatable and axially movable. A first cam plate having an extending portion radially outward and having cam mechanisms formed on both surfaces of the extending portion, and the extending portion of the first cam plate being sandwiched in the axial direction and the first cam plate A cam mechanism is formed on the surface facing the extending portion of the first and second cam plates, and is supported so as to be relatively non-rotatable radially inward of the clutch inner and slidably provided independently in the driven shaft direction. An assist cam mechanism is provided between the three cam plates and the first cam plate and the second cam plate for increasing the pressure contact force of the friction plate group when the rotational force of the drive shaft exceeds the rotational force of the driven shaft. A back torque limiter cam mechanism is provided between the first cam plate and the third cam plate to reduce the pressure contact force of the friction plate group when a predetermined back torque is generated on the driven shaft. The present invention relates to a multi-plate clutch.

  According to a second aspect of the present invention, in the multi-plate clutch according to the first aspect, the first cam plate has a disk shape, and the number of cams disposed on one surface is disposed on the other surface. More than the number of cams.

  According to a third aspect of the present invention, in the multi-plate clutch according to the first aspect, the first cam plate includes a boss extending in both directions in the driven shaft direction, and the second cam plate and the third cam plate are The first cam plate is slidably held on the outer periphery of the boss portion.

  According to a fourth aspect of the present invention, in the multi-plate clutch according to the first aspect, the first cam plate includes a boss extending in both directions of the driven shaft, and the second cam plate and the third cam plate are the first cam plate. One cam plate is slidably held on the outer periphery of a boss portion, and an O-ring is disposed on the sliding portion.

  According to a fifth aspect of the present invention, in the multi-plate clutch according to the first aspect, the resilient member is disposed between the second cam plate and the clutch inner and between the third cam plate and the clutch inner. It is characterized by.

  According to a sixth aspect of the present invention, in the multi-plate clutch according to the first aspect, the assist cam mechanism or the back torque limiter cam mechanism is a mechanism composed of a concave-convex cam that is fitted to each other or a cam mechanism in which a ball is inserted. It is characterized by this.

  According to the first aspect of the present invention, it is possible to achieve both functions of increasing the clutch capacity during acceleration of the vehicle and releasing the back torque when shifting down with a simple structure. Further, the functions of the assist cam member and the back torque limiter cam member can be made independent to set the optimum operation.

  According to the invention of claim 2, for example, the optimum strength can be set by increasing the number of cams of the frequently used assist function than the number of cams of the back torque limiter function.

  According to the third aspect of the present invention, it becomes easy to dispose the second cam plate and the third cam plate on both sides of the first cam plate.

  According to the invention of claim 4, the processing accuracy between the sliding portions can be relaxed and the productivity can be improved.

  According to the invention of claim 5, it is not necessary to increase the accuracy of the gap between the cams in the rotational direction. Further, since no impact is generated on the cam, the change of the clutch capacity is changed linearly and smoothly. Further, cam surface wear and impact noise are reduced. Since the relative displacement in the rotational direction of the cam is eliminated, the cam can always be in close contact and lash can be eliminated.

  According to the sixth aspect of the present invention, a mechanism having both functions of the assist cam mechanism and the back torque limiter cam mechanism can be formed.

  FIG. 1 is a longitudinal sectional view of a multi-plate clutch 1 according to a first embodiment of the present invention. This clutch is installed on a rotational power transmission path from the crankshaft of an internal combustion engine of a vehicle such as a motorcycle to the main shaft of the transmission, and is connected / disconnected in accordance with a shift operation of the driver.

  In the figure, a transmission main shaft 2 is rotatably supported by a crankcase (not shown) via a ball bearing 3. A sleeve 4 and a sleeve 5 are provided on the transmission main shaft 2 adjacent to the ball bearing 3, and a driven gear 7 that always meshes with the driving gear of the crankshaft via the needle bearing 6 on the outer periphery of the sleeve 5. It is supported so that relative rotation is possible. A buffer member 8 is provided between the main body of the driven gear 7 and the peripheral tooth portion. A clutch outer 9 is provided adjacent to the driven gear 7, and the boss portion 9 a is held on the outer periphery of the boss portion 7 a of the driven gear 7. The clutch outer 9 is connected by a rivet 10 so as to rotate integrally with the driven gear 7.

  A clutch inner 11 is provided inside the clutch outer 9. The clutch outer 9 is provided with a plurality of drive friction plates 12 which are engaged with the clutch outer so as not to rotate relative to the clutch outer and to be movable in the axial direction. The clutch inner 11 is provided with a plurality of driven friction plates 13 that are engaged with the clutch inner so as not to rotate relative to the clutch inner and move in the axial direction. The driving friction plates 12 and the driven friction plates 13 are alternately arranged to form a friction plate group. A pressure plate 11a is integrally formed at the outer end of the clutch inner 11 and is in contact with the outer end side of the friction plate group. A pressure receiving plate 15 is adjacent to the boss portion 7 a of the driven gear 7 via an annular spacer 14. The boss portion 15a of the pressure receiving plate 15 is supported by being spline fitted to the transmission main shaft 2. The outer peripheral portion of the pressure receiving plate 15 is in contact with the far end side of the friction plate group.

  Adjacent to the boss portion 15a of the pressure receiving plate 15, the boss portion 16a of the first cam plate 16 is spline-fitted and supported on the transmission main shaft 2. The first cam plate 16 includes an extension portion 16b on the outer side in the radial direction of the main shaft 2, and cam mechanisms are formed on both surfaces of the extension portion.

  A second cam plate 17 and a third cam plate 18 are paired with an inwardly projecting spline 11b provided on the inner peripheral portion of the clutch inner 11, and the extended portion 16b of the first cam plate 16 is pivoted on the shaft 16b. At the positions sandwiched in the direction, each is slidably fitted in the axial direction. The first cam plate 16 includes a boss portion 16a extending in both directions in the transmission main shaft direction. The boss portion 17a of the second cam plate 17 and the boss portion 18a of the third cam plate 18 are fitted on the outer periphery of the boss portion 16a of the first cam plate 16 so as to be slidable in the axial direction. An O-ring 19 is attached to the sliding surface. Cam mechanisms are respectively formed between the second cam plate 17 and the third cam plate 18 between the opposing surfaces of the extending portions 16 b of the first cam plate 16. A washer 20 and a nut 21 are provided adjacent to the boss portion 16a of the first cam plate 16, and the pressure receiving plate 15 and the first cam plate 16 are fixed so as not to move in the axial direction.

  The O-ring 19 is formed between the boss portion 16a of the first cam plate 16 and the boss portion 17a of the second cam plate 17, and between the boss portion 16a of the first cam plate 16 and the third cam plate 18. The sliding surface is slid between the O-ring 19 and the outer surface of the boss portion 16a of the first cam plate 16 instead of sliding between metals. That is, the dimensional tolerance between the sliding surfaces of the boss portion 16a of the first cam plate 16 and the boss portions 17a and 18a of the second and third cam plates 17 and 18 is slightly loosened, and the second cam plate 17 and third Since the cam plate 18 is allowed to be slightly inclined, the contact surface contact between the plurality of convex cams and the concave cams can be equalized. As a result, the tolerance management of the cam mechanism is also loosened, so that productivity is improved.

  An operating rod 22 is fitted to the end of the central hole 2a of the main shaft 2. An operation plate 24 is held on the outer peripheral portion via a ball bearing 23, and the outer periphery of the operation plate 24 is engaged with a stop ring 25 mounted on the inner periphery of the clutch inner 11. A stop ring 26 is provided at the inner peripheral side inner part of the clutch inner 11, and a disc spring 28 for pressing the second cam plate 17 via a spring receiving member 27 is provided. Further, a disc spring 30 is provided that pushes the third cam plate 18 via a spring receiving member 29 provided adjacent to the outer peripheral portion of the operation plate 24. The disc spring 28 is more powerful than the disc spring 30. The disc spring 28 pushes the second cam plate 17 toward the first cam plate 16 at the inner peripheral portion and pushes the clutch inner 11 toward the pressure receiving plate 15 at the outer peripheral portion, that is, the friction plate group press-contact direction. The other disc spring 30 is a weaker spring than the disc spring 28, but pushes the third cam plate 18 toward the first cam plate 16 at the inner peripheral portion and moves the clutch inner 11 toward the friction plate group separating direction at the outer peripheral portion. Is pushing. Since the disc spring 28 is stronger, the friction plate group is pushed in the press-contact direction by the biasing force of the disc spring as a whole when the internal combustion engine is stopped and during normal operation.

  When disconnecting the clutch, pull the operating rod 22 outward of the clutch against the overall biasing force of the disc spring, move the clutch inner 11 outward, and separate the friction plates 12, 13 As a result, the clutch is disengaged. In addition, by pushing the clutch inner 11 with springs from both sides as described above, the operational stability of the clutch inner 11 is improved, thereby preventing backlash, so that tolerance tolerance can be increased and productivity is increased. improves. Further, since the second cam plate and the third cam plate are pushed toward the first cam plate on the small diameter side of the disc spring, the positions of the contact surfaces of the convex cam and the concave cam are stabilized.

  In FIG. 1, an assist cam mechanism is formed between a first cam plate 16 and a second cam plate 17. This is a mechanism comprising an assist concave cam 31 provided on the first cam plate 16 and an assist convex cam 32 provided on the second cam plate 17. Further, a slipper cam mechanism is formed between the first cam plate 16 and the third cam plate 18. This is a mechanism comprising a slipper concave cam 33 provided on the first cam plate 16 and a slipper convex cam 34 provided on the third cam plate 18. An oil hole 16 c is formed in the boss portion 16 a of the first cam plate 16. Thereby, oil can be supplied to the space surrounded by the first, second, and third cam plates and the clutch inner 11 from the center hole 2a of the transmission main shaft 2 to lubricate the cam mechanism.

  2 and 3 are perspective views of the cam plate. 2A is a perspective view of the first cam plate 16, and FIG. 2B is a perspective view of the second cam plate 17, both of which show the shape of the opposing surface on which the assist cam is formed. Six assist concave cams 31 are formed on one surface of the extended portion 16 b of the first cam plate 16. Six assist convex cams 32 are formed on the surface of the second cam plate 17 facing the concave cam 31. Both the back of the concave cam 31 and the head of the convex cam 32 are finished in a spherical shape. A groove provided in a protrusion on the peripheral portion of the second cam plate 17 is a fitting groove 17 b that fits into the spline 11 b of the clutch inner 11.

  3A is a perspective view of the first cam plate 16, and FIG. 3B is a perspective view of the third cam plate 18. Each of them shows the shape of the facing surface on which the slipper cam is formed. Three slipper concave cams 33 are formed on the surface of the extended portion 16b of the first cam plate 16 opposite to the assist concave cam 31. Three slipper convex cams 34 are formed at a portion of the third cam plate 18 facing the concave cam 33. Both the back of the concave cam 33 and the head of the convex cam 34 are finished in a spherical shape. A groove provided in a protrusion on the periphery of the third cam plate 18 is a fitting groove 18 b that fits into the spline 11 b of the clutch inner 11.

  FIG. 4 is a front view of the surface of the first cam plate 16 on which the slipper concave cam 33 shown in FIG. 3A is formed. A cross section of the slipper convex cam 34 engaging with the concave cam 33 is also shown. The assist concave cam 31 formed on the opposite surface and the assist convex cam 32 engaged therewith are indicated by broken lines. When the surface shown in FIG. 4 is viewed from the axial direction, the biconcave cams 31 and 33 are arranged with their circumferential positions shifted so as not to overlap, so that the extension portion 16b of the first cam plate 16 is thinned. Can be formed.

  In FIG. 1, when the internal combustion engine is stopped, the disc springs 28 and 30 press the clutch inner 11 as a whole, so that the driving friction plate 12 and the driven friction plate 13 are pressed against each other between the pressure plate 11a and the pressure receiving plate 15. Yes. When driving torque from the internal combustion engine is input to the multi-plate clutch 1 through the driven gear 7, the clutch outer 9 rotates and is pressed against the driving friction plate 12 engaged with the clutch outer 9 and the driving friction plate 12. The driven friction plate 13, the clutch inner 11 engaged with the driven friction plate 13, and the second cam plate 17 and the third cam plate 18 that are spline fitted to the clutch inner 11 rotate together.

  FIG. 5 is a developed sectional view taken along the line V-V in FIG. 4. The direction of rotation of the cam plate in the figure is the direction of arrow R in the figure. On both sides of the central first cam plate 16, the second cam plate 17 and the third cam plate 18 can slightly move independently of each other in the left-right direction in the drawing with respect to the first cam plate 16.

  In FIG. 5, when the rotation starts, the drive torque A1 is applied to the second cam plate 17 and the third cam plate 18 which are rotating in the same direction as described above. The assist convex cam 32 formed on the second cam plate 17 is in contact with a facing point 35 on one inclined surface of the peripheral edge of the assist concave cam 31 formed on the first cam plate 16 in advance. When the rotation starts, the second cam plate 17 pushes the first cam plate 16 in the rotation direction with a pressing force A2 corresponding to the driving torque A1, and transmits the driving torque A1. The slipper convex cam 34 formed on the third cam plate 18 also moves in the same direction as the driving torque A1, but the distance from the peripheral edge of the slipper concave cam 33 formed on the first cam plate 16 is increased. Yes, since it is not in contact with the opposing point, torque transmission on the slipper cam side is not performed. The first cam plate 16 is also driven with the driving torque A1 by the driving torque A1 transmitted from the assist cam. The drive torque A1 is transmitted to the transmission main shaft 2 that is spline-fitted to the first cam plate 16, and the transmission main shaft 2 also rotates with the drive torque A1. The above is the rotational driving force transmission mechanism during the normal operation of the multi-plate clutch 1.

  As the driving torque A1 input to the multi-plate clutch 1 from the internal combustion engine through the driven gear 7 increases, the assisting force A2 applied to the opposing point 35 on the assisting concave cam 31 by the assisting convex cam 32 increases. The convex cam 32 itself is pushed in the inclined plane direction by the component A3 in the inclined plane direction of the pressing force A2. When the sum of the components of A3 in the transmission main shaft direction exceeds the pressing force applied to the second cam plate via the disc spring 28, the second cam plate 17 moves in the direction of the component A3 along the inclined surface. . This movement is transmitted to the clutch inner 11 via the disc spring 28 and pushes the pressure plate 11a integrated with the clutch inner 11 in the direction in which the friction plates 12 and 13 are pressed. The second cam plate 17 moves in the direction of the inclined surface of the assist concave cam in accordance with the magnitude of the driving torque A1 from the internal combustion engine, and the pressure plate 11a supports the pressure contact force of the friction plates 12 and 13 ( It moves in the direction of assist) and transmits the increased driving torque. The amount of movement of the second cam plate 17 is determined by the balance with the reaction force of the pressing force from the friction plate group.

  Next, when the vehicle brakes the engine, the multi-plate clutch is driven from the wheel via the transmission main shaft 2 through the first cam plate 16 by the driving torque A1 input to the multi-plate clutch 1 through the driven gear 7. The back torque B1 transmitted to 1 may be larger. This excessive back torque is the torque applied to the clutch through the transmission main shaft while the tire slips on the ground. If the multi-plate clutch 1 remains in the connected state, the tire will continue to slip, resulting in unstable handling, wear of the tire, and further burden on the drive system. In this case, it is better to relax the braking force applied to the tire from the engine and to freely rotate the tire to some extent.

  In FIG. 5, arrow B1 indicates the direction of the back torque. One inclined surface of the peripheral portion of the slipper concave cam 33 provided on the first cam plate is in contact with the opposing point 36 of the base of the slipper convex cam 34 on the third cam plate in advance. When the back torque B1 transmitted from the transmission main shaft 2 becomes larger than the drive torque A1, the peripheral portion of the slipper concave cam 33 pushes the opposing point 36 of the slipper convex cam 34 with the pressing force B2 corresponding to the back torque B1. Then, the third cam plate 18 is pushed in the rotational direction via the slipper convex cam 34. The distance between the peripheral edge portion of the assist concave cam and the base portion of the assist convex cam on the other side is larger than that in the case of the slipper cam. Not done.

  When the back torque B1 increases and the pressing force B2 applied to the opposing point 36 of the slipper convex cam 34 by the peripheral edge of the slipper concave cam 33 increases, the slipper convex cam 34 itself tilts the reaction force of the pressing force B2. It is pushed in the direction of the inclined surface by the component B3 in the surface direction. When the sum of the components of B3 in the transmission main shaft direction exceeds the pressing force applied to the third cam plate via the disc spring 30, the third cam plate 18 moves in the direction of the reaction force component B3 along the inclined surface. Move to. This movement is transmitted to the clutch inner 11 via the disc spring 30, and the pressure plate 11a integrated with the clutch inner 11 is moved in the direction in which the friction plates 12, 13 are separated. That is, when the back torque B1 from the transmission main shaft becomes larger than the drive torque A1, the third cam plate 18 moves, the pressure contact force of the pressure plate 11a against the friction plate is reduced, and the friction plates 12 and 13 are slid. Let As a result, the slipper cam mechanism reduces torque transmission, functions as a back torque limiter, stabilizes vehicle operation, and prevents tire wear.

  FIG. 6 is a longitudinal sectional view of a multi-plate clutch 40 according to the second embodiment of the present invention. A boss portion 41a of the first cam plate 41 is supported by spline fitting on the transmission main shaft. The first cam plate 41 includes an extending portion 41b on the outer side in the radial direction of the main shaft 2, and cam mechanisms are formed on both surfaces of the extending portion. The second cam plate 42 and the third cam plate 43 are paired with an inwardly projecting spline provided on the inner peripheral portion of the clutch inner 11 so that the extended portion 41b of the first cam plate 41 is axially disposed. Are respectively slidably fitted in the axial direction at positions sandwiched between the two. The first cam plate 41 includes a boss portion 41a extending in both directions of the transmission main shaft direction. The boss portion 42a of the second cam plate 42 and the boss portion 43a of the third cam plate 43 are fitted on the outer periphery of the boss portion 41a of the first cam plate 41 so as to be axially slidable. An O-ring is attached to the sliding surface. Cam mechanisms are respectively formed between the second cam plate 42 and the third cam plate 43 between the opposing surfaces of the extending portions 41 b of the first cam plate 41.

  This embodiment is different from the first embodiment in that the first cam plate 41, the second cam plate 42, and the third cam plate 43 are provided with receiving recesses that function as concave cams, and the convex cams function as these. The steel balls 44 that are to be stored are accommodated. That is, the steel ball 44 is accommodated between the accommodating recess 45 of the first cam plate 41 and the accommodating recess 46 of the second cam plate 42 and functions as the assist cam 50. Further, a steel ball 44 is interposed between the housing recess 47 of the first cam plate 41 and the housing recess 48 of the third cam plate 43, and functions as a slipper cam 51. The configuration other than the above is the same as that of the first embodiment. In the figure, members having the same shape and function as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment.

  FIG. 7 is a front view of the first cam plate 41 as viewed from the third cam plate 43 side. A steel ball 44 functioning as a slipper cam 51 of the first cam plate 41 and its accommodating recess 47 are shown by solid lines. An inclined surface 47a formed at one end of the housing recess 47 is also shown. The steel ball 44 functioning as the assist cam 50 on the opposite side, the accommodating recess 45, and the inclined surface 45a are indicated by broken lines. When the surface shown in FIG. 7 is viewed from the axial direction, the housing recesses 45 and 47 provided in the first cam plate 41 are arranged so as to be shifted in the circumferential direction so as not to overlap with each other. The extending portion 41b can be formed thin.

  8 is a developed sectional view taken along the line VIII-VIII in FIG. The rotation direction of the cam plates 41, 42, 43 is the direction of the arrow R. On both sides of the central first cam plate 41, the second cam plate 42 and the third cam plate 43 are independently relative to the first cam plate 41 in the rotational direction and slightly in the axial direction. Separation is possible. Arrow A1 indicates the direction of driving torque applied to the second cam plate 42 and third cam plate 43, and arrow B1 indicates the direction of back torque applied to the first cam plate 41. A cam having an accommodation recess on the second cam plate 42 side is an assist cam 50, and a cam having an accommodation recess on the third cam plate 43 side is a slipper cam 51.

  The assist cam 50 accommodates a steel ball 44 in a housing recess 45, 46 formed on the opposing surface of the first cam plate 41 and the second cam plate 42. Inclined surfaces 45a and 46a are formed at symmetrical positions with respect to the centers of the steel balls 44 of the housing recesses 45 and 46, respectively. The inclined surface 46a of the second cam plate 42 is provided on the side facing the driving torque A1, and the inclined surface 45a of the first cam plate 41 is provided on the side indicated by the driving torque A1.

  The slipper cam 51 accommodates a steel ball 44 in a housing recess 47, 48 formed on the opposing surface of the first cam plate 41 and the third cam plate 43. Inclined surfaces 47a and 48a are formed at symmetrical positions with respect to the centers of the steel balls 44 of the housing recesses 47 and 48, respectively. The inclined surface 47a of the first cam plate 41 is provided on the side facing the back torque B1, and the inclined surface 48a of the third cam plate 43 is provided on the side indicated by the back torque B1.

  When the driving torque A1 input to the multi-plate clutch 40 from the internal combustion engine through the driven gear increases and exceeds the back torque B1, the second cam plate 42 and the third cam plate 43 are driven with respect to the first cam plate 41. Move forward in the direction of torque. At this time, the second cam plate 42 rolls the steel ball 44, and the steel ball 44 rides on the inclined surfaces 45a and 46a. When such riding up occurs, the second cam plate 42 is pushed away from the first cam plate 41. When this pressing force exceeds the pressing force applied to the second cam plate 42 via the disc spring 28, the second cam plate 42 is separated from the first cam plate 41 and receives the clutch inner 11 via the disc spring 28. Push in the direction of plate 15. That is, the pressure plate 11a is moved in a direction to assist (assist) the pressure contact force of the friction plate, and the increased driving torque is transmitted. Although driving torque is also applied to the third cam plate 43, no inclined surface is formed between the first cam plate 41 and the first cam plate 41 in the direction in which the steel ball rides up. Absent.

  In FIG. 5, arrow B1 indicates the direction of the back torque. When the back torque B1 transmitted from the transmission main shaft 2 becomes larger than the drive torque A1, the first cam plate 41 pushes the third cam plate 43 through the steel ball 44 by the pressing force corresponding to the back torque B1. When the back torque exceeds a certain value, the first cam plate 41 advances relative to the third cam plate 43 in the same direction as the back torque B1, and the first cam plate 41 rolls the steel ball 44, The steel ball 44 rides on the inclined surfaces 47a and 48a. When such riding up occurs, the third cam plate 43 is pushed away from the first cam plate 41. When this pressing force exceeds the pressing force applied to the third cam plate 43 via the disc spring 30, the third cam plate 43 is separated from the first cam plate 41, and the clutch inner 11 is moved via the disc spring 30. The friction plates are moved in a direction to relax the pressure contact force, and the friction plates are slid with respect to each other. As a result, the slipper cam mechanism reduces the transmission of torque from the drive source, functions as a back torque limiter, stabilizes the steering of the vehicle, and prevents tire wear. The pressing force of the first cam plate 41 to which the back torque is applied is also applied to the second cam plate 42, but the steel ball is inclined in the direction in which the steel ball rides between the first cam plate 41 and the second cam plate 42. Since the surface is not formed, the second cam plate 42 and the first cam plate 41 are not separated from each other.

As described in detail above, the following effects are brought about in the embodiment of the present invention.
(1) With a simple structure, it is possible to achieve both functions of increasing the clutch capacity when accelerating the vehicle and releasing the back torque when shifting down. Further, the functions of the assist cam member and the back torque limiter cam member can be made independent to set the optimum operation.
(2) It is possible to set the optimum strength by increasing the number of cams of the frequently used assist function than the number of cams of the back torque limiter function.
(3) Since the first cam plate has bosses extending in both directions of the driven shaft direction, it is easy to dispose the second cam plate and the third cam plate on both sides of the first cam plate, respectively. Become.
(4) Since the O-ring is arranged in the sliding portion, the processing accuracy between the sliding portions can be relaxed and the productivity can be improved.
(5) Since the resilient member is disposed between the second cam plate and the clutch inner and between the third cam plate and the clutch inner, it is not necessary to increase the accuracy of the clearance between the cams in the rotational direction. Become. Further, since no impact is generated on the cam, the change of the clutch capacity is changed linearly and smoothly. Further, cam surface wear and impact noise are reduced.
(6) Since the assist cam mechanism and the back torque limiter cam mechanism employ a mechanism composed of a concave-convex cam or a cam mechanism in which a ball is inserted, the functions of both the assist cam mechanism and the back torque limiter cam mechanism. Can be formed independently.

1 is a longitudinal sectional view of a multi-plate clutch 1 according to a first embodiment of the present invention. (A) is a perspective view of the 1st cam plate 16, (b) is a perspective view of the 2nd cam plate 17, and all have shown the shape of the assist cam. (A) is a perspective view of the 1st cam plate 16, (b) is a perspective view of the 3rd cam plate 18, and all have shown the shape of the slipper cam. 3 is a front view of a surface of the first cam plate 16 on which a slipper concave cam 33 is formed. FIG. It is a VV cross-section expanded view of FIG. It is a longitudinal cross-sectional view of the multi-plate clutch 40 of 2nd Embodiment of this invention. FIG. 4 is a front view of the first cam plate 41 as viewed from the third cam plate 43 side. It is a VIII-VIII cross-section expanded view of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Multi-plate clutch, 9 ... Clutch outer, 11 ... Clutch inner, 11a ... Pressure plate, 12 ... Drive friction plate, 13 ... Driven friction plate, 15 ... Pressure receiving plate, 16 ... First cam plate, 16a ... Boss part , 17 ... 2nd cam plate, 18 ... 3rd cam plate, 19 ... O-ring, 28 ... Belleville spring, 30 ... Belleville spring, 31 ... Assist concave cam, 32 ... Assist convex cam, 33 ... Slipper concave cam, 34 ... Slipper convex cam, 40 ... multi-plate clutch of the second embodiment, 41 ... first cam plate, 41a ... boss portion, 42 ... second cam plate, 43 ... third cam plate, 44 ... steel ball, 45 ... receiving recess 45a ... inclined surface, 46 ... receiving recess, 46a ... inclined surface, 47 ... receiving recess, 47a ... inclined surface, 48 ... receiving recess, 48a ... inclined surface, 50 ... assist cam, 51 ... slipper cam.

Claims (6)

A clutch outer that is rotationally driven from the drive shaft;
A clutch inner connected to the driven shaft;
A plurality of drive friction plates engaged with the clutch outer so as not to be rotatable relative to the clutch outer and axially movable;
A plurality of driven friction plates, which are engaged with the clutch inner so as not to rotate relative to the clutch inner and are movable in the axial direction, and are alternately arranged with the driving friction plates;
In a multi-plate clutch comprising a resilient member that press-contacts the friction plate group in the axial direction and frictionally engages the clutch outer and a clutch inner,
A first cam plate which is disposed so as not to be rotatable relative to the driven shaft and is not movable in the axial direction, and has an extension portion radially outward of the driven shaft, and cam mechanisms are formed on both surfaces of the extension portion;
The extending portion of the first cam plate is sandwiched in the axial direction, and a cam mechanism is formed on a surface facing the extending portion of the first cam plate, and is supported so as not to be relatively rotatable radially inward of the clutch inner. And a second cam plate and a third cam plate that are slidable independently from each other in the driven shaft direction,
An assist cam mechanism is provided between the first cam plate and the second cam plate to increase the pressure contact force of the friction plate group when the rotational force of the drive shaft exceeds the rotational force of the driven shaft.
A back torque limiter cam mechanism is provided between the first cam plate and the third cam plate to reduce a pressure contact force of the friction plate group when a predetermined back torque is generated on the driven shaft. Plate clutch. The multi-plate clutch according to claim 1, wherein the first cam plate has a disk shape, and the number of cams arranged on one surface is larger than the number of cams arranged on the other surface. The first cam plate includes a boss extending in both directions of the driven shaft direction,
The multi-plate clutch according to claim 1, wherein the second cam plate and the third cam plate are slidably held on an outer periphery of a boss portion of the first cam plate. The first cam plate includes a boss extending in both directions of the driven shaft,
2. The second cam plate and the third cam plate are slidably held on an outer periphery of a boss portion of the first cam plate, and an O-ring is disposed on the sliding portion. The multi-plate clutch described in 1. The multi-plate clutch according to claim 1, wherein a resilient member is disposed between the second cam plate and the clutch inner and between the third cam plate and the clutch inner. 2. The multi-plate clutch according to claim 1, wherein the assist cam mechanism or the back torque limiter cam mechanism is a mechanism composed of a concave-convex cam fitted to each other or a cam mechanism into which a ball is inserted.

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