JP5363385B2 - Multi-plate clutch - Google Patents

Description

  According to the present invention, a clutch outer coupled to an input member, a clutch inner coupled to an output member, a plurality of drive friction plates engaged with the clutch outer, and the drive friction plates are alternately stacked. A plurality of driven friction plates engaged with the clutch inner, a plurality of the driving friction plates, and a pressure receiving plate disposed opposite to the friction plate disposed at one end in the axial direction among the driven friction plates And a pressing plate that sandwiches the plurality of the driving friction plates and the driven friction plates between the pressure receiving plates, and the side that presses the driving friction plates and the driven friction plates between the pressure receiving plates. The present invention relates to a multi-plate clutch including a pressing plate urging unit that exerts a spring urging force that urges the pressing plate, and a pressure-bonding force increasing mechanism that increases the urging force of the pressing plate by the pressing plate urging unit during acceleration.

  In order to reduce the clutch operating load, some clutch springs are disabled to cancel the urging force of some clutch springs among the multiple clutch springs that are applying urging force to the pressing plate when the clutch is disengaged. Patent Document 1 discloses a multi-plate clutch provided with a pressure-bonding force releasing means.

Japanese Patent No. 3107692

  However, in the multi-plate clutch disclosed in the above-mentioned Patent Document 1, in order to disable the clutch spring by the pressure-bonding force releasing means, a release spring that urges a member constituting a part of the pressure-bonding force releasing means is a clutch. This is necessary separately from the spring, resulting in an increase in the number of parts and a complicated structure.

  The present invention has been made in view of such circumstances, eliminates the need for a release spring, reduces the number of parts and simplifies the structure, enhances the pressure-bonding force during acceleration, and clutch operating load during normal clutch disengagement. An object of the present invention is to provide a multi-plate clutch that can reduce the above-mentioned problem.

  To achieve the above object, the present invention provides a clutch outer coupled to an input member, a clutch inner coupled to an output member, a plurality of drive friction plates engaged with the clutch outer, A plurality of driven friction plates that are alternately overlapped with the driving friction plates and engaged with the clutch inner, and a plurality of the driving friction plates and a friction plate that is disposed at one axial end of the driven friction plates A pressure receiving plate disposed opposite to each other, a pressing plate that sandwiches the plurality of driving friction plates and the driven friction plate between the pressure receiving plates, and the driving friction plate and the driven friction plate with the pressure receiving plate. A pressing plate urging means that exerts a spring urging force that urges the pressing plate on the side to be pressed between, and a pressing force increasing mechanism that increases the urging force of the pressing plate by the pressing plate urging means during acceleration. For plate clutch The pressing plate urging means moves along the moving direction of the pressing plate and a first clutch spring provided between the pressing plate and the pressure receiving plate so that a spring urging force is always applied to the pressing plate. And a second clutch spring provided between the pressing plate and a movable portion that constitutes a part of the pressure-bonding force enhancing mechanism, and the pressure-bonding force-enhancing mechanism is an urging force of the first clutch spring during acceleration. In addition to moving the movable portion to the side where the urging force of the second clutch spring is applied to the pressing plate, but in the state other than the time of acceleration, the urging force applied to the pressing plate from the second clutch spring is weakened. A first feature is that the movable portion is configured to move.

  According to the present invention, in addition to the configuration of the first feature, the movable portion is the clutch inner, and the second clutch spring is held through the coiled second clutch spring that is received at one end by the pressing plate. A second feature is that a boss portion is provided integrally with the clutch inner, and the other end of the second clutch spring is brought into contact with a spring receiving portion provided at a tip of the boss portion.

  According to the present invention, in addition to the configuration of the second feature, the pressure-bonding force increasing mechanism coaxially surrounds the fixed cam member so that the fixed cam member is fixed to the output member and operates with the clutch inner. An inclined tooth-shaped movable cam formed on the inner periphery of the movable cam member is slidably contacted with an inclined tooth-shaped fixed cam formed on the outer periphery of the fixed cam member. This is the third feature.

  In addition to the configuration of the third feature, the fourth feature of the present invention is that the movable cam member formed separately from the clutch inner is fixed to the clutch inner.

  A fifth feature of the present invention is that, in addition to any of the first to fourth features, a collar or a washer is interposed between the first clutch spring and the pressing plate. .

  In addition to any of the configurations of the first to fifth features, the present invention includes a plurality of first and second clutch springs each having a coil shape that is long in the axial direction of the pressing plate. A sixth feature is that a housing recess is formed.

  The seventh feature of the present invention is that, in addition to any of the first to sixth features, the urging force of the second clutch spring is set smaller than the urging force of the first clutch spring.

  In addition to the configuration of the second feature, the present invention moves the pressing plate to the side separating the pressure receiving plate when a torque in the reverse direction acts on the output member between the clutch inner and the pressing plate. An eighth feature is that a back torque limiter mechanism is provided, and a part of the back torque limiter mechanism is constituted by the clutch inner.

  The main shaft 11 of the embodiment corresponds to the output member of the present invention, the primary driven gear 16 of the embodiment corresponds to the input member of the present invention, and the clutch inner 18 of the embodiment serves as the movable part of the present invention. Correspond.

  According to the first feature of the present invention, the pressing plate urging means that exerts the spring urging force that urges the pressing plate is provided between the pressing plate and the pressure receiving plate so that the spring urging force always acts on the pressing plate. The first clutch spring and a second clutch spring provided between the movable part and the pressing plate constituting a part of the pressure-enhancing force increasing mechanism, and the pressure-enhancing force-enhancing mechanism serves as an urging force of the first clutch spring during acceleration. In addition, the movable portion is moved to the side where the urging force of the second clutch spring acts on the pressing plate, and the movable portion is moved from the second clutch spring to the side where the urging force acting on the pressing plate is weakened in a state other than during acceleration. Therefore, the release spring is not required, the number of parts is reduced and the structure is simplified. By reducing reduces clutch operation load, it is possible to increase the pressing force of the driving friction plates and the biasing force greatly to the driven friction plates of the pressing plate by the pressing plate biasing means during acceleration.

  According to the second feature of the present invention, the movable portion constituting a part of the pressure-bonding force increasing mechanism is a clutch inner, and the boss portion that penetrates the second clutch spring and holds the second clutch spring is the clutch inner. Since the other end of the coiled boss part, which is provided integrally with one end and is received by the pressing plate, is in contact with the spring receiving part provided at the tip of the boss part, a part of the pressure-bonding force enhancement mechanism is configured with a clutch inner Thus, the number of parts can be reduced.

  According to the third feature of the present invention, a part of the pressure-enhancing force-enhancing mechanism is composed of a fixed cam member fixed to the output member and a movable cam member coaxially surrounding the fixed cam member so as to move together with the clutch inner. And the slanted movable cam on the inner periphery of the movable cam member is in sliding contact with the slanted fixed cam on the outer periphery of the fixed cam member, so that the axial direction of the fixed cam member and the movable cam member Compared to the case where cams are formed on the opposing surfaces, dead space is less likely to occur, and the multi-plate clutch can be reduced in the axial direction.

  According to the fourth aspect of the present invention, since the movable cam member separate from the clutch inner is fixed to the clutch inner, only the movable cam member requiring strength or wear resistance is matched to the characteristics. Compared with the case where the clutch inner and the movable cam member are integrally molded, the cost can be reduced.

  According to the fifth aspect of the present invention, since the collar or the washer is interposed between the first clutch spring and the pressing plate, the first clutch spring can be adjusted by adjusting the length of the collar or the thickness of the washer. The spring urging force can be easily adjusted, and the clutch operating load can be easily set.

  According to the sixth aspect of the present invention, the first and second clutch springs that are coiled in the axial direction of the pressing plate are respectively stored in the plurality of receiving recesses formed in the pressing plate. Further, it is possible to avoid an increase in the axial direction of the multi-plate clutch due to the arrangement of the second clutch spring.

  According to the seventh aspect of the present invention, since the biasing force of the second clutch spring is smaller than the biasing force of the first clutch spring, the pressure-bonding force that moves the movable portion against the spring biasing force of the second clutch spring. The operating force of the strengthening mechanism can be set small, and the crimping force enhancing mechanism can be downsized.

  Further, according to the eighth feature of the present invention, the back torque limiter mechanism that moves the pressing plate to the side separating from the pressure receiving plate when the torque in the reverse direction acts on the output member is partially constituted by the clutch inner. In this way, the back torque limiter mechanism can be configured while suppressing an increase in the number of parts because it is provided between the clutch inner and the pressing plate.

It is sectional drawing at the time of acceleration of a multi-plate clutch. It is sectional drawing which follows the 2-2 line of FIG. It is sectional drawing corresponding to FIG. 1 in states other than the time of acceleration of a multi-plate clutch. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1 with the clutch outer omitted. FIG. 5 is a cross-sectional view taken along line 5-5 in FIG.

  DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 5. First, in FIG. 1, for example, a crankshaft (not shown) of an engine mounted on a motorcycle and a gear transmission (see FIG. A primary speed reduction device 12, a damper spring 13 and a multi-plate clutch 14 are interposed between the main shaft 11 and a primary drive gear (not shown) provided on the crankshaft. And a primary driven gear 16 meshing with the primary drive gear, and the primary driven gear 16 is supported on the main shaft 11 so as to be relatively rotatable.

  The multi-plate clutch 14 includes a clutch outer 17 connected to the primary driven gear 16 serving as an input member via a damper spring 13, a clutch inner 18 connected to the main shaft 11 serving as an output member, and the clutch The plurality of drive friction plates 19, 19... Engaged with the outer 17 so as not to rotate relative to each other, and the drive friction plates 19, 19. Of the plurality of driven friction plates 20, 20... And the driving friction plates that are arranged at one end in the axial direction among the plurality of the driving friction plates 19, 19. A pressure plate 21 disposed opposite to the pressure plate 21 and a plurality of the drive friction plates 19, 19... And the driven friction plates 20, 20. And a pressing plate urging means that exerts a spring urging force that urges the pressing plate 22 toward the side where the driving friction plates 19, 19... And the driven friction plates 20, 20. 23, a pressure-bonding force increasing mechanism 24 for increasing the urging force of the pressing plate 22 by the pressing plate urging means 23 during acceleration, and the pressure plate 22 when the reverse torque is applied to the main shaft 11. And a back torque limiter mechanism 25 that is moved to the side to be separated from 21.

  A cylindrical sleeve 27 is fitted on the outer periphery of the main shaft 11 at a portion corresponding to the primary speed reducer 12 with the direction along the axis of the main shaft 11 being constant. A needle bearing 28 is interposed between the inner periphery of the primary driven gear 16.

  The clutch outer 17 integrally includes a cylindrical outer cylindrical portion 17a and an end wall portion 17b connected to an end portion of the outer cylindrical portion 17a on the primary driven gear 16 side, and is opposite to the primary driven gear 16. The end wall portion 17 b is connected to the primary driven gear 16 through the damper spring 13. Further, the outer peripheral portions of the plurality of drive friction plates 19, 19... Are engaged with the inner periphery of the outer cylindrical portion 17a while allowing axial movement and disabling relative rotation.

  The clutch inner 18 includes a cylindrical inner cylindrical portion 18a that is coaxially disposed in the outer cylindrical portion 17a of the clutch outer 17, and an inner portion that projects radially inward from an axially intermediate portion of the inner cylindrical portion 18a. It has an orientation flange portion 18b integrally, and the inner peripheral portions of the plurality of driven gears 20, 20... Are engaged with the outer periphery of the inner cylindrical portion 18a so as to be able to move in the axial direction and disable relative rotation. The

The pressure receiving plate 21 is disposed at a position interposed between the end wall portion 17b of the clutch outer 17 and the clutch inner 18, and the inner periphery of the pressure receiving plate 21 is coupled to the outer periphery of the main shaft 11 so as not to be relatively rotatable. A ring-shaped washer 29 is interposed between the inner peripheral portion of the plate 21 and the inner peripheral portion of the primary driven gear 16 and the sleeve 27. The multi-plate clutch 14 is an engine cover 30 provided in the engine. The other end of the operating shaft 31 whose one end is fitted to the engine cover 30 so as to be axially movable is coaxially and slidably fitted to the main shaft 11. The inner periphery of the pressing plate 22 is connected to the intermediate portion of the operating shaft 31 via a clutch bearing 32. An operation shaft 33 for switching the connection / disconnection of the multi-plate clutch 14 is rotatably supported on the engine cover 30, and a lever 34 is provided at an end of the operation shaft 33 protruding from the engine cover 30. . Thus, the other end of the operating shaft 31 is connected to the inner end of the operating shaft 33 so as to move in the axial direction in accordance with the rotation of the operating shaft 33.

  Referring also to FIG. 2, the crimping force increasing mechanism 24 coaxially surrounds the fixed cam member 36 that is fixed to the main shaft 11 and operates together with the clutch inner 18. The ring-shaped movable cam member 37 and the clutch inner 18 which is a movable portion are provided, and the clutch inner 18 is moved from the pressing plate urging means 23 to the side for increasing the urging force acting on the pressing plate 22 during acceleration. However, the clutch inner 18 is moved from the pressing plate urging means 23 to the side where the urging force acting on the pressing plate 22 is weakened in a state other than during acceleration.

  The fixed cam member 36 is integrally connected to a cylindrical boss portion 36a that coaxially surrounds the main shaft 11 and is coupled to the main shaft 11 so as not to rotate relative to the main shaft 11, and one end portion of the boss portion 36a. A ring plate portion 36b, and a nut 39 is an end portion of the main shaft 11 so as to sandwich the washer 29, the inner peripheral portion of the pressure receiving plate 21, the boss portion 36a and the washer 38 between the sleeve 27 and the sleeve 27. The pressure receiving plate 21 and the fixed cam member 36 are fixed to the main shaft 11 by being screwed together. Further, the ring plate portion 36b of the fixed cam member 36 is provided with a plurality of lightening holes 40 for weight reduction.

  The movable cam member 37 is formed separately from the clutch inner 18, and is disposed between the inward flange portion 18 b of the clutch inner 18 and the pressure receiving plate 21, so that the ring plate of the fixed cam member 36 is provided. .. Are inserted into the inner cylindrical portion 18a of the clutch inner 18 while coaxially surrounding the portion 36b, and a plurality of rivets 41, 41,... It is fixed to the inward flange 18b. That is, the movable cam member 37 is fixed to the clutch inner 18 and operates together with the clutch inner 18.

  .. Are formed on the outer periphery of the ring plate portion 36b of the fixed cam member 36. The fixed cams 42 are formed on the inner periphery of the movable cam member 37. A plurality of, for example, 36 slanted movable cams 43, 43,... Slidably contacting the fixed cams 42, 42,.

  Therefore, the fixed cams 42, 42... Of the fixed cam member 36 fixed to the main shaft 11 in the state where the movement in the axial direction is blocked and the movable cams 43, 43. 14, the movable cam member 37 and the clutch inner 18 move to the side closer to the pressure receiving plate 21 as shown in FIG. When the multi-plate clutch 14 is not accelerated, the movable cam member 37 and the clutch inner 18 move to the side away from the pressure receiving plate 21 as shown in FIG.

  Referring also to FIG. 4, the pressing plate urging means 23 includes a plurality of, for example, three coils provided between the pressing plate 22 and the pressure receiving plate 21 so that a spring urging force is always applied to the pressing plate 22. A plurality of, for example, three coil-shaped first clutch springs 45, and a plurality of, for example, three coil-shaped first clutch springs 45 provided between the clutch inner 18 and the pressing plate 22 that can move along the moving direction of the pressing plate 22. The urging force of the second clutch springs 46 is set smaller than the urging force of the first clutch springs 45.

  Referring also to FIG. 5, the pressing plate 22 is formed with first accommodating recesses 47 for accommodating the first clutch springs 45, toward the inward flange 18 b side of the clutch inner 18. The projecting bottomed cylindrical first tube portions 49 are integrally protruded at equal intervals in the circumferential direction, and the second housing recesses 48 for housing the second clutch springs 46 are formed. The bottomed cylindrical second cylindrical portion 50 projecting toward the inward flange portion 18b of the clutch inner 18 is positioned in the middle portion between the first cylindrical portions 49, and so on in the circumferential direction. Projected integrally at intervals.

  In addition, the pressure receiving plate 21 and the fixed cam member 36 are fixed to the main shaft 11 on a part of the inner end side walls of the first tube portions 49 and the second tube portions 50. Notches 51... 52 for avoiding interference with the nut 39 to be screwed are provided. Accordingly, the first clutch springs 45 housed in the first housing recesses 47 and the second clutch springs 46 housed in the second housing recesses 48 can be disposed closer to the main shaft 11. Become.

  The closed end walls of the first receiving recesses 47 are provided with first insertion holes 53, and the second insertion holes 54 are formed in the inwardly facing flange portion 18b of the clutch inner 18 at positions corresponding to the first insertion holes 53. Are provided in the ring plate portion 36b of the fixed cam member 36 at a position corresponding to the second insertion holes 54, and the pressure receiving plate 22 is provided at a position corresponding to the third insertion holes 55. Are provided with fourth insertion holes 56.

  In the second, third, and fourth insertion holes 54, 55, 56, the enlarged diameter heads 57a are inserted into and engaged with the fourth insertion holes 56, with the enlarged diameter heads 57a being unrotatable. Are inserted through the first insertion holes 53, one end of a cylindrical boss member 58 is inserted into the second insertion hole 55, and one end of the boss member 58 is inserted into one end of the boss member 58. The first bolts 57 are screwed together.

  The boss members 58 are provided with second bolts 59 having enlarged diameter heads 59a that also function as spring receiving portions, and the enlarged diameter heads 59a are brought into contact with and engaged with the other ends of the boss members 58. And are screwed together. The first clutch springs 45 are accommodated in the first accommodating recesses 47 so as to be held by the boss members 58, and one end portions of the first clutch springs 45 are arranged on the pressing plate 22. The other end of the first clutch springs 45 is in contact with the enlarged diameter heads 59a of the second bolts 59. In addition, a collar or a washer, in this embodiment a washer 60, is interposed between the closed end wall of the first accommodating recesses 47 and one end of the first crankshaft 45. Thus, the second bolts 59 are fixedly connected to the pressure receiving plate 21 via the boss members 58 and the first bolts 59. The first clutch springs 45 are connected to the pressing plate 22. Is provided between the pressure receiving plate 21 and the pressing plate 22 so that the washers 60 are interposed therebetween, and always exerts a spring force that urges the pressing plate 22 toward the pressure receiving plate 21 side.

  By the way, the pressure receiving plate 21 and the pressing plate 22 are relatively displaced in the circumferential direction by a slight angle when the crimping force increasing mechanism 24 is operated. In order to allow such relative displacement, the boss member 58 is inserted. The first insertion holes 53 provided in the pressing plate 22 and the first receiving recesses 47 formed in the pressing plate 22 so that the boss members 58 are inserted are elliptical long in the circumferential direction of the pressing plate 22. Formed.

  The closed end walls of the second accommodating recesses 48 are provided with fifth insertion holes 61. On the other hand, a cylindrical boss 13c that projects through the fifth insertion holes 61 and enters the second housing recess 48 is integrally formed on the inward flange 18b of the clutch inner 18. In the boss portion 13c, a third bolt 62 having an enlarged head portion 62a that functions as a spring receiving portion is brought into contact with and engaged with the enlarged head portion 62a at the tip of the boss portion 13c. The diameter-enlarged heads 62a are provided at the tip ends of the bosses 13c.

  The second clutch springs 46 accommodated in the second accommodating recesses 48 are held by the boss portions 13c penetrating the second clutch springs 46, and one end portion of the second clutch springs 46. Are received by the closed end walls of the second accommodating recesses 48. Moreover, the other end part of 2nd clutch spring 46 ... is contact | abutted to the said enlarged diameter head part 62a ... provided in the front-end | tip of the boss | hub part 13c .... In addition, a collar or a washer, in this embodiment a washer 63... Is interposed between the closed end wall of the second accommodating recess 48... And one end of the second clutch spring 46. 46 ... are provided between the clutch inner 18 and the pressing plate 22 with a washer 63 interposed between the pressing plate 22 and exert a spring force that urges the pressing plate 22 toward the pressure receiving plate 21 side. To do.

  By the way, the pressure-enhancing force increasing mechanism 24 moves the clutch inner 18 to the side away from the pressing plate 22 at the time of acceleration. The diameter-enlarged heads 62a of the third bolts 62 ... Since it moves to the side close to the closed end wall, the spring force of the second clutch springs 46 is strengthened, and in addition to the spring force of the first clutch springs 45, it is biased toward the pressure receiving plate 21 side. The spring force of the second clutch springs 46 strengthened by the pressing plate 22 acts on the side to be pressed. Further, in a state other than during acceleration, the diameter-enlarged heads 62a of the third bolts 62 move to the side away from the closed end wall of the second accommodating recesses 48, so that the pressing plate 22 is moved from the second clutch spring 46. The urging force acting on the is weakened.

  The back torque limiter mechanism 25 moves between the clutch inner 18 and the pressing plate 22 so as to move the pressing plate 22 to the side away from the pressure receiving plate 21 when a reverse torque is applied to the main shaft 11. Is provided.

  Thus, the back torque limiter mechanism 25 includes a pressing cam 65 provided on the inner periphery of the inner cylindrical portion 18a of the clutch inner 18, and a pressure receiving cam 66 provided on the pressing plate 22 so as to be in sliding contact with the pressing cam 65. A part of the back torque limiter mechanism 25 is configured by the clutch inner 18.

  Next, the operation of this embodiment will be described. The spring urging force that urges the pressing plate 22 to the side to be pressure-bonded between the driving friction plates 19 and the driven friction plates 20. The pressing plate urging means 23 is configured to cause the spring urging force to always act on the pressing plate 22, and the first clutch spring 45 provided between the pressing plate 22 and the pressure receiving plate 21, along the moving direction of the pressing plate 22. The clutch inner 18 that can move and second clutch springs 46 provided between the pressing plates 22, and the pressure-enhancing force-enhancing mechanism 24 includes a second clutch spring in addition to the urging force of the first clutch springs 45 during acceleration. Although the clutch inner 18 is moved to the side where the urging force of 46... Is applied to the pressing plate 22, the second clutch spring is in a state other than during acceleration. 46 ... are configured to allowed to move the clutch inner 18 on the side to weaken the urging force acting on the pressing plate 22 from.

  Accordingly, the release spring is not required, the number of parts is reduced and the structure is simplified, and at the time of normal clutch disengagement, the urging force of the pressing plate 22 by the pressing plate urging means 23 is reduced to reduce the clutch operating load and accelerate. Sometimes, the urging force of the pressing plate 22 by the pressing plate urging means 23 can be increased to increase the pressing force of the driving friction plates 19 and the driven friction plates 20.

  Further, a boss portion 18c that passes through the coil-like second clutch springs 46, one end of which is received by the pressing plate 22, and holds the second clutch springs 46 in the clutch inner 18 constituting a part of the crimping force increasing mechanism 24. Are integrally provided, and the other end of the second clutch spring 46 is brought into contact with the enlarged diameter heads 62a provided at the tip of the boss portion 18c. Thus, the number of parts can be reduced.

  The crimping force increasing mechanism 24 includes a fixed cam member 36 that is fixed to the main shaft 11 and a movable cam member 37 that operates together with the clutch inner 18 to coaxially surround the fixed cam member 36. Since the slanted-shaped movable side cams 43 formed on the inner periphery of the movable cam member 37 are slidably contacted with the slanted-shaped fixed side cams 42 formed on the outer periphery of the fixed cam member 36. Compared with the case where the cam is formed on the surface of the movable cam member 37 facing the axial direction, a dead space is less likely to be generated, and the multi-plate clutch 14 can be reduced in the axial direction.

  Further, since the movable cam member 36 is formed separately from the clutch inner 18 and is fixed to the clutch inner 18, only the movable cam member 36 that requires strength or wear resistance is made of a material suitable for the characteristics. Compared to the case where the clutch inner 18 and the movable cam member 36 are integrally formed, the cost can be reduced.

  Also, since the washers 60 are interposed between the first clutch springs 45 and the pressing plate 22, the spring biasing force of the first clutch springs 45 can be easily adjusted by adjusting the thickness of the washers 60. It is possible to adjust, and it becomes easy to set the clutch operation load.

  In addition, a plurality of first and second receiving recesses 47, 48, which respectively house first and second clutch springs 45, 46, which are coiled in the axial direction of the pressing plate 22 in the pressing plate 22, respectively. Therefore, the increase in the axial direction of the multi-plate clutch 14 due to the arrangement of the first and second clutch springs 45, 46,... Can be avoided.

  Also, since the urging force of the second clutch springs 46 is set to be smaller than the urging force of the first clutch springs 45, the pressing force that moves the clutch inner 18 against the spring urging force of the second clutch springs 46. The operating force of the reinforcing mechanism 24 can be set small, and the crimping force increasing mechanism 24 can be downsized.

  Further, a back torque limiter mechanism 25 is provided between the clutch inner 18 and the pressing plate 22 to move the pressing plate 22 away from the pressure receiving plate 21 when reverse torque is applied to the main shaft 11. Since a part of the torque limiter mechanism 25 is configured by the clutch inner 18, the back torque limiter mechanism 25 can be configured while suppressing an increase in the number of parts.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 11 ... Main shaft 14 which is an output member ... Multi-plate clutch 16 ... Primary driven gear 17 which is an input member ... Clutch outer 18 ... Clutch inner 18c as a movable part ... Boss part DESCRIPTION OF SYMBOLS 19 ... Drive friction plate 20 ... Driven friction plate 21 ... Pressure receiving plate 22 ... Pressing plate 23 ... Pressing plate urging means 24 ... Crimping force increasing mechanism 25 ... Back torque limiter mechanism 36 ... fixed cam member 37 ... movable cam member 42 ... fixed side cam 43 ... movable side cam 45 ... first clutch spring 46 ... second clutch springs 47, 48 ... Housing recess 60 ... Washer 62a ... Expanded head as a spring receiving part

Claims (8)

  A clutch outer (17) coupled to the input member (16), a clutch inner (18) coupled to the output member (11), and a plurality of drive friction plates ( 19), a plurality of driven friction plates (20) that are alternately overlapped with the drive friction plates (19) and engaged with the clutch inner (18), and a plurality of the drive friction plates (19). ) And the driven friction plate (20), a pressure receiving plate (21) disposed opposite to the friction plate disposed at one end in the axial direction, a plurality of the drive friction plates (19) and the driven friction plates. The pressure plate (22) sandwiching (20) between the pressure receiving plate (21), the driving friction plate (19) and the driven friction plate (20) are pressure-bonded between the pressure receiving plate (21). Spring biasing force that biases the pressing plate (22) to the side In the multi-plate clutch, comprising: a pressing plate urging means (23) to be exerted; and a pressure-bonding force increasing mechanism (24) for increasing the urging force of the pressing plate (22) by the pressing plate urging means (23) during acceleration. A first clutch spring (45) provided between the pressing plate (22) and the pressure receiving plate (21) so that a plate urging means (23) always applies a spring urging force to the pressing plate (22); And a first portion provided between the pressing plate (22) and the movable portion (18) that constitutes a part of the pressure-bonding force enhancement mechanism (24) that can move along the moving direction of the pressing plate (22). The clutch pressure-enhancing mechanism (24) includes a biasing force of the second clutch spring (46) in addition to the biasing force of the first clutch spring (45) during acceleration. Although the movable part (18) is moved to the side acting on the pressure plate (22), the urging force acting on the pressing plate (22) is weakened from the second clutch spring (46) in a state other than during acceleration. A multi-plate clutch configured to move the movable part (18).   The movable portion is the clutch inner (18), and a boss portion that holds the second clutch spring (46) through the coiled second clutch spring (46), one end of which is received by the pressing plate (22). (18c) is provided integrally with the clutch inner (18), and the other end of the second clutch spring (46) is brought into contact with a spring receiving portion (62a) provided at the tip of the boss portion (18c). The multi-plate clutch according to claim 1.   The fixed cam member (36) is coaxially arranged so that the crimping force increasing mechanism (24) operates together with the fixed cam member (36) fixed to the output member (11) and the clutch inner (18). And a movable cam member (37) that surrounds, and is formed on an inner periphery of the movable cam member (37) on an inclined fixed cam (42) formed on the outer periphery of the fixed cam member (36). 3. A multi-plate clutch according to claim 2, wherein said inclined toothed movable cam (43) is in sliding contact.   The multi-plate clutch according to claim 3, wherein the movable cam member (36) formed separately from the clutch inner (18) is fixed to the clutch inner (18).   The multi-plate clutch according to any one of claims 1 to 4, wherein a collar or a washer (60) is interposed between the first clutch spring (45) and the pressing plate (22). .   The pressing plate (22) is formed with a plurality of receiving recesses (47, 48) for receiving first and second clutch springs (45, 46) each having a long coil shape in the axial direction of the pressing plate (22). The multi-plate clutch according to any one of claims 1 to 5, wherein   The multi-plate clutch according to any one of claims 1 to 6, wherein an urging force of the second clutch spring (46) is set smaller than an urging force of the first clutch spring (45).   When the reverse torque acts on the output member (11) between the clutch inner (18) and the pressing plate (22), the pressing plate (22) is separated from the pressure receiving plate (21). The multi-plate clutch according to claim 2, wherein a back torque limiter mechanism (25) for moving is provided, and a part of the back torque limiter mechanism (25) is constituted by the clutch inner (18).

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