JP2009030792A - Centrifugal clutch and vehicle having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compact a centrifugal clutch having a clutch release mechanism and to stabilize the release point. <P>SOLUTION: This centrifugal clutch 2 comprises a clutch housing 46, a clutch boss 48, a plate group 66, a pressure plate 77, a roller retainer 78, a belleville spring 83, a pressing body 40a, and the clutch release mechanism 86. The pressure plate 77 brings the plate group 66 into the state of pressure contact by displacing to the other side in the axial direction to press the plate group directly or indirectly. With respect to the centrifugal direction, the belleville spring 83 extends from one end toward the other in the direction tilted to the axial direction. One end of the belleville spring 83 is directly or indirectly fixed to the clutch housing 46. The belleville spring 83 biases the roller retainer 78 directly or indirectly to the other side by the other end thereof. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a centrifugal clutch and a vehicle including the centrifugal clutch.

For example, Patent Literature 1 discloses a centrifugal clutch provided with a clutch release mechanism (“clutch release mechanism” is also referred to as “clutch release mechanism”). FIG. 19 is a cross-sectional view of the centrifugal clutch 200 disclosed in Patent Document 1. As shown in FIG. As shown in FIG. 19, the centrifugal clutch 200 includes a clutch drum 201, a clutch hub 202, and a plate group 205. The plate group 205 includes a drive plate 204 that rotates together with the clutch drum 201, and a driven plate 203 that rotates together with the clutch hub 202. In the centrifugal clutch 200, the space between the pressure plate 210 and the moving plate 207 is widened by the centrifugal force acting on the centrifugal ball 208 and the urging force of the clutch spring 206, while the bottom of the pressure plate 210 and the clutch drum 201. The distance between is reduced. As a result, the plate group 205 is in a pressure contact state.
JP-A-4-316724

  In Patent Document 1, the clutch spring 206 is constituted by a compression coil spring. Therefore, it is necessary to separately arrange the end plate 209 that receives the urging force of the clutch spring 206 so as to face the moving plate 207. Further, the end plate 209 and the moving plate 207 must be relatively rigid so that they do not deform when receiving the urging force of the clutch spring 206. That is, when the clutch spring 206 formed of a compression coil spring is used, it is necessary to provide the end plate 209 and the moving plate 207 that have relatively high rigidity and a large thickness. Therefore, there is a problem that the clutch becomes large.

  This invention is made | formed in view of such a point, The place made into the objective is to attain compactization in the centrifugal clutch provided with the clutch release mechanism.

  The clutch according to the present invention includes a clutch housing, a clutch boss, a plate group, a pressure member, a retainer, a leaf spring, a pressing body, and a clutch release mechanism. The clutch housing rotates about the axis. The clutch boss is disposed inside the clutch housing. The clutch boss rotates about the axis. The plate group includes a friction plate and a clutch plate. The friction plate rotates with the clutch housing. The clutch plate faces the friction plate so as to be displaceable in the axial direction of the axis. The clutch plate rotates with the clutch boss. The pressure member is disposed on one side of the plate group. The pressure member rotates with the clutch housing. The pressure member can be displaced in the axial direction of the axis. The pressure member is displaced to the other side with respect to the axial direction of the axis, thereby pressing the plate group directly or indirectly to bring the plate group into a pressure contact state. The retainer faces the surface on one side of the pressure member. The retainer rotates with the clutch housing. The retainer is supported directly or indirectly on the clutch housing so as to be displaceable in the axial direction of the axis. The retainer together with the pressure member forms a space that becomes narrower as it moves away from the axis. The leaf spring is provided between the clutch housing and the retainer on one side of the retainer. The leaf spring extends in a direction inclined with respect to the axial direction of the axis from one end to the other end with respect to the centrifugal direction. One end of the leaf spring is fixed directly or indirectly to the clutch housing. The leaf spring biases the retainer directly or indirectly with the other end of the leaf spring to the other side. The pressing body is disposed in a space between the pressure member and the retainer. The pressing body turns around the axis along with the rotation of the clutch housing. The pressing body moves in a direction away from the axis while pressing the pressure member toward the plate group side by centrifugal force generated during turning. The clutch release mechanism presses the pressure member to one side to release the pressure contact state of the plate group.

  ADVANTAGE OF THE INVENTION According to this invention, size reduction of the centrifugal clutch provided with the clutch release mechanism and stabilization of a release point can be achieved.

Embodiment 1
(Outline of this embodiment)
In this embodiment, as shown in FIG. 1, a plate spring 83 which is a kind of plate spring is used as a biasing means for directly or indirectly biasing the plate group 66, and the plate spring 83 is used as a plate group. 66, the centrifugal clutch 2 is made compact by being arranged on the same side as the input side pressing body 40a.

  Hereinafter, a clutch embodying the present invention and a vehicle equipped with the clutch will be described taking the centrifugal clutch 2 shown in FIG. 1 and the motorcycle 1 shown in FIG. 3 as examples. However, the motorcycle 1 and the centrifugal clutch 2 are merely examples of preferred embodiments in which the present invention is implemented. The present invention is not limited to the motorcycle 1 and the centrifugal clutch 2. The vehicle according to the present invention may be, for example, an off-road type motorcycle, a scooter or a moped, or a straddle-type vehicle such as ATV: All Terrain Vehicle. The vehicle according to the present invention may be a vehicle other than the saddle riding type vehicle represented by a four-wheeled vehicle or the like. Here, in this specification, the “motorcycle” means not only a so-called motorcycle in a narrow sense but also a motorcycle in a broad sense including off-road vehicles, scooters, mopeds, and the like.

  In the following description, the front, rear, left, and right directions are directions viewed from a passenger seated on the seat 16 shown in FIG. Moreover, in FIG. 1, the centrifugal clutch 2 in a different state is shown in an upper part and a lower part from the axis AX. Specifically, the portion above the axis AX represents a state where the plate group 66 is not in pressure contact. A portion below the axis AX represents a state in which the plate group 66 is in pressure contact. FIG. 2 shows only a part of the power unit 3 for convenience of explanation.

  FIG. 1 is a cross-sectional view of a centrifugal clutch 2 according to the present embodiment. FIG. 2 is a schematic configuration diagram of a power unit 3 using the centrifugal clutch 2. FIG. 3 is a left side view of the motorcycle 1 using the power unit 3. First, a schematic configuration of the motorcycle 1 will be described mainly with reference to FIG.

(Schematic configuration of the motorcycle 1)
As shown in FIG. 3, the motorcycle 1 includes a body frame 10. The vehicle body frame 10 has a head pipe 11. A handle 12 is attached to the upper side of the head pipe 11. On the other hand, a front wheel 14 is rotatably attached to the lower side of the head pipe 11 via a front fork 13.

  A fuel tank 15 is attached to the body frame 10. A seat 16 is disposed at a substantially central portion in the front-rear direction of the vehicle body.

  The power unit 3 is suspended from the body frame 10. A pivot shaft 17 is provided in the rear half of the body frame 10. A rear arm 18 is swingably supported on the pivot shaft 17. The rear arm 18 is supported by the vehicle body frame 10 via a link mechanism 20 and a rear cushion unit 21.

  A rear wheel 19 is rotatably attached to the rear end portion of the rear arm 18. The rear wheel 19 is provided with a driven sprocket 22. On the other hand, a drive sprocket 24 is provided on the drive shaft 23 of the power unit 3. A chain 25 as a driving force transmission mechanism is wound around the driving sprocket 24 and the driven sprocket 22. The power of the power unit 3 is transmitted to the rear wheel 19 by the chain 25. Thereby, the rear wheel 19 rotates.

  In the present invention, the driving force transmission mechanism that transmits the power from the power unit 3 to the rear wheel 19 is not limited to the chain 25. The driving force transmission mechanism may be, for example, a drive shaft or a belt.

(Power unit 3)
Next, the configuration of the power unit 3 will be described in detail with reference mainly to FIG. As shown in FIG. 2, the power unit 3 includes an engine 4, a transmission mechanism 5, and a centrifugal clutch 2. In the present invention, the type of engine is not particularly limited. In the present embodiment, an example in which the engine 4 is a water-cooled four-cycle parallel four-cylinder engine will be described.

-Engine 4-
The engine 4 is arranged such that a cylinder shaft (not shown) extends slightly obliquely upward toward the front of the vehicle body. The engine 4 includes a crankcase 31 and a crankshaft 32 shown in FIG. The crankshaft 32 is housed in the crankcase 31. The crankshaft 32 is disposed so as to extend in the vehicle width direction.

-Transmission mechanism 5-
As shown in FIG. 2, the crankshaft 32 is connected to the transmission mechanism 5 via the centrifugal clutch 2. The transmission mechanism 5 includes a main shaft 33, a drive shaft 23, and a gear selection mechanism 36. The main shaft 33 is connected to the crankshaft 32 via the centrifugal clutch 2. The main shaft 33 and the drive shaft 23 are disposed substantially parallel to the crankshaft 32, respectively.

  A multi-stage transmission gear 34 is attached to the main shaft 33. On the other hand, a plurality of transmission gears 35 corresponding to the multi-stage transmission gears 34 are mounted on the drive shaft 23. The plurality of transmission gears 34 and the plurality of transmission gears 35 mesh with each other only with a pair of selected gears. At least one of the transmission gear 34 other than the selected transmission gear 34 among the plurality of transmission gears 34 and the transmission gear 35 other than the selected transmission gear 35 among the plurality of transmission gears 35 is a main shaft. 33 or the drive shaft 23 is rotatable. In other words, at least one of the transmission gear 34 that is not selected and the transmission gear 35 that is not selected is idled with respect to the main shaft 33 or the drive shaft 23. That is, the rotation transmission between the main shaft 33 and the drive shaft 23 is performed only through the selected transmission gear 34 and the selected transmission gear 35 that mesh with each other.

  The transmission gears 34 and 35 are selected by a gear selection mechanism 36. Specifically, the transmission gears 34 and 35 are selected by the shift cam 37 of the gear selection mechanism 36. A plurality of cam grooves 37 a are formed on the outer peripheral surface of the shift cam 37. A shift fork 38 is mounted in each cam groove 37a. Each shift fork 38 is engaged with predetermined transmission gears 34 and 35 of the main shaft 33 and the drive shaft 23, respectively. As the shift cam 37 rotates, each of the plurality of shift forks 38 is guided by the cam groove 37 a and moves in the axial direction of the main shaft 33. Thereby, the gear which meshes with each other among the transmission gears 34 and 35 is selected. Specifically, among the plurality of transmission gears 34 and 35, only a pair of gears at positions corresponding to the rotation angle of the shift cam 37 are fixed to the main shaft 33 and the drive shaft 23 by splines, respectively. Thus, the transmission gear position is determined, and rotation transmission is performed between the main shaft 33 and the drive shaft 23 at a predetermined transmission ratio via the transmission gears 34 and 35. As a result, power is transmitted to the rear wheel 19 via the chain 25 shown in FIG. 3, and the rear wheel 19 rotates.

  The gear selection mechanism 36 is operated by a shift pedal (not shown).

-Centrifugal clutch 2-
Next, the configuration of the centrifugal clutch 2 will be described in detail with reference mainly to FIG. The centrifugal clutch 2 is a centrifugal clutch that can be operated by the rider. In the present embodiment, an example in which the centrifugal clutch 2 is a wet multi-plate friction clutch will be described.

-Input side clutch member 44 (= clutch housing 46)-
The centrifugal clutch 2 includes an input side clutch member 44. The input side clutch member 44 rotates about the axis AX of the main shaft 33. In the present embodiment, the input side clutch member 44 is constituted by a clutch housing 46. The clutch housing 46 is formed in a cylindrical shape with one end closed. The main shaft 33 passes through the clutch housing 46. The clutch housing 46 has the same axis AX as the main shaft 33.

  FIG. 4 is a perspective view of the clutch housing 46 as viewed obliquely from above. As shown in FIG. 4, the clutch housing 46 includes a housing body 46c. The housing main body 46c is formed in a cylindrical shape whose one end is closed by the bottom 46a. An insertion hole 46b into which the main shaft 33 is inserted is formed in the bottom 46a. The housing body 46c is provided with a plurality of pairs of arms 46d. Each arm 46d is formed so as to protrude radially inward from the inner peripheral surface of the housing body 46c. Each arm 46d extends from the bottom 46a toward the outside in the vehicle width direction. The arm 46d has an inner portion 46e that is located relatively inside the vehicle width direction and an outer portion 46f that is located relatively outside the vehicle width direction. The thickness of the inner portion 46e in the radial direction is thicker than the same thickness of the outer portion 46f. For this reason, an end face 46h is formed at the boundary between the inner portion 46e and the outer portion 46f. Moreover, the linear groove | channel 46g extended in the circumferential direction is formed in the front-end | tip part of the outer side part 46f.

  As shown in FIG. 1, a scissors gear 45 is attached to the clutch housing 46. Specifically, the clutch housing 46 is fixed so as not to rotate with respect to a gear 45a described below. The axis line of the scissors gear 45 is common to the axis line of the clutch housing 46. As shown in FIG. 2, the scissors gear 45 meshes with the gear 32 a of the crankshaft 32. For this reason, as the crankshaft 32 rotates, the scissors gear 45 and the clutch housing 46 rotate integrally.

  Specifically, as shown in FIG. 1, the scissor gear 45 includes two gears 45 a and 45 b, a spring 49, and two plates 51 and 52. The gear 45a and the gear 45b are located between the two plates 51 and 52. The two plates 51 and 52 are fixed to each other in the axial direction of the main shaft 33 by fixing means such as rivets and screws. Thus, the two gears 45 a and 45 b are substantially fixed to each other with respect to the axial direction of the main shaft 33. On the other hand, the gear 45a and the gear 45b are rotatable with respect to the rotation direction.

  The gear 45a and the gear 45b have the same number of teeth. The gear 45a and the gear 45b are arranged so that their teeth are alternately positioned in the circumferential direction. The spring 49 is provided between the gear 45a and the gear 45b. Therefore, squeezing torque is applied to the gear 45 a and the gear 45 b by the spring 49. Thereby, the fluctuation torque of the engine 4 is absorbed.

  Between the scissor gear 45 and the main shaft 33, a needle bearing 53 and a spacer 54 fixed so as not to rotate with respect to the main shaft 33 are disposed. The scissors gear 45 is rotatable with respect to the main shaft 33 by the needle bearing 53. That is, the rotation of the scissors gear 45 is not transmitted directly to the main shaft 33.

  A sprocket 55 is in contact with the inner end face of the scissors gear 45 in the vehicle width direction. The sprocket 55 is for driving an oil pump (not shown). The main shaft 33 is inserted into the sprocket 55. The sprocket 55 has the same axis AX as the main shaft 33. A bearing 56 and a collar 57 are disposed between the sprocket 55 and the main shaft 33. The collar 57 is fixed so as not to rotate with respect to the main shaft 33. The bearing 56 is disposed between the collar 57 and the sprocket 55. For this reason, the sprocket 55 is rotatable with respect to the main shaft 33. Therefore, the sprocket 55 rotates together with the scissors gear 45 separately from the main shaft 33. As a result, an oil pump or the like connected to the sprocket 55 is driven by power transmission means such as a belt or a chain.

  A spacer 59 and a bearing 58 are disposed inside the collar 57 in the vehicle width direction. The spacer 59 is in contact with the collar 57, but is not in contact with the sprocket 55. The spacer 59 contacts the inner ring 58a of the bearing 58, but does not contact the outer ring 58b.

  An outer ring 58 b of the bearing 58 is fixed to the crankcase 31. That is, the right end portion of the main shaft 33 is rotatably supported by the crankcase 31 by the bearing 58. On the other hand, as shown in FIG. 7, the left end portion of the main shaft 33 is rotatably supported by the crankcase 31 by a bearing 94.

  The bearing 58 is attached to the main shaft 33 so as not to be displaced in the axial direction of the axis AX of the main shaft 33. On the other hand, a thrust bearing 63 is disposed between the clutch boss 48 and the scissors gear 45. The scissors gear 45, the needle bearing 53, the spacer 54, the sprocket 55, the bearing 56, the collar 57, and the spacer 59 are fixed with respect to the axial direction of the axis AX of the main shaft 33 by the bearing 58 and the thrust bearing 63.

  A disc spring 61 and a washer 62 are disposed between the spacer 59 and the bearing 58. The washer 62 is in contact with only the outer ring 58 b of the bearing 58. The washer 62 is urged toward the inner side in the axial direction of the axis AX of the main shaft 33 by the disc spring 61. In other words, the washer 62 is urged toward the outer ring 58 b side of the bearing 58 by the disc spring 61. For this reason, when the main shaft 33 rotates, a sliding resistance is generated at least between the disc spring 61 and the washer 62 and between the washer 62 and the outer ring 58b. This sliding resistance becomes, for example, a rotational resistance when the main shaft 33 rotates in a state where the centrifugal clutch 2 is disconnected. Thereby, for example, when the centrifugal clutch 2 is disconnected, the rotation of the main shaft 33 is relatively fast.

~ Plate group 66 ~
A plurality of friction plates 64 serving as input side clutch plates are arranged inside the clutch housing 46. Each friction plate 64 is fixed to the clutch housing 46 with respect to the rotation direction of the main shaft 33. For this reason, the plurality of friction plates 64 rotate together with the clutch housing 46. Each friction plate 64 can be displaced in the axial direction of the axis AX of the main shaft 33. For this reason, the distance between the friction plates 64 adjacent to each other is variable.

  The plurality of friction plates 64 are arranged in the axial direction of the axis AX of the main shaft 33. A clutch plate 65 as an output side clutch plate is disposed between the friction plates 64 adjacent to each other. The clutch plate 65 faces the adjacent friction plate 64 so as to be displaceable with respect to the axis AX direction of the main shaft 33. Each clutch plate 65 is fixed to the clutch boss 48 in the axial direction of the axis AX of the main shaft 33. For this reason, the plurality of clutch plates 65 rotate together with the clutch boss 48. Each clutch plate 65 can be displaced with respect to the axial direction of the axis AX of the main shaft 33. For this reason, the distance between the clutch plates 65 adjacent to each other is variable.

  In the present embodiment, the plurality of friction plates 64 and the plurality of clutch plates 65 constitute a plate group 66.

  The plate group 66 may be provided with a judder spring for smoothing a load change when the centrifugal clutch 2 is connected. Specifically, for example, a judder spring may be disposed between the clutch plate 65 and the friction plate 64, and the clutch plate 65 and the friction plate 64 may be urged away from each other.

-Output side clutch member 47 (= clutch boss 48)-
A clutch boss 48 as the output side clutch member 47 is disposed inside the clutch housing 46. The clutch boss 48 is fixed to the main shaft 33 by a nut 67 so as not to rotate. That is, the clutch boss 48 rotates about the axis AX together with the main shaft 33.

-Roller retainer 69-
A shaft 68 is disposed outside the main shaft 33 in the vehicle width direction. The shaft 68 is press-fitted between the main shaft 33 and the pressure plate 77. The shaft 68 rotates together with the main shaft 33. The shaft 68 can be displaced in the axial direction of the axis AX of the main shaft 33. A roller retainer 69 is attached to the shaft 68. The roller retainer 69 cannot rotate with respect to the shaft 68. That is, the roller retainer 69 rotates with the shaft 68. On the other hand, with respect to the axial direction of the shaft 68, the roller retainer 69 can be displaced with respect to the shaft 68.

  The roller retainer 69 extends from the shaft 68 toward the outside in the radial direction. The outer end in the radial direction of the roller retainer 69 faces the plate group 66 in the axial direction of the axis AX of the main shaft 33. The roller retainer 69 is displaced toward the inner side in the vehicle width direction together with the shaft 68, so that the distance between the roller retainer 69 and the bottom 46a of the clutch housing 46 is shortened. As a result, the plate group 66 is directly pressed by the roller retainer 69. As a result, the plate group 66 is in a pressure contact state. Specifically, the friction plate 64 and the clutch plate 65 are in pressure contact with each other. As a result, a frictional force in the rotational direction is generated between the friction plate 64 and the clutch plate 65. As a result, the clutch boss 48 rotates together with the clutch housing 46.

  On the other hand, when the roller retainer 69 is displaced together with the shaft 68 toward the outside in the vehicle width direction, the distance between the roller retainer 69 and the bottom portion 46a of the clutch housing 46 is increased. As a result, the pressure contact state of the plate group 66 is released. Therefore, the frictional force in the rotational direction between the friction plate 64 and the clutch plate 65 becomes relatively small. As a result, the rotation of the clutch housing 46 is not transmitted to the clutch boss 48.

  As described above, in the present embodiment, the centrifugal clutch 2 is intermittently engaged by the roller retainer 69 being displaced inward and outward in the vehicle width direction.

  Note that a plurality of output-side offsprings 71 as output-side urging members are arranged between the clutch boss 48 and the roller retainer 69 at equal intervals along the circumferential direction. The roller retainer 69 is biased in a direction away from the plate group 66 by the plurality of output-side off springs 71. As a result, the roller retainer 69 is relatively away from the bottom 46 a of the clutch housing 46 when the urging force directed inward in the vehicle width direction is not applied to the roller retainer 69. Therefore, the plate group 66 is in a non-pressure contact state. In addition, the output side offspring 71 can be comprised by a compression coil spring, for example.

  The stronger the elastic force of the output-side offspring 71, the more difficult the centrifugal clutch 2 is connected, and the more easily the centrifugal clutch 2 is disconnected. On the other hand, the weaker the elastic force of the output-side offspring 71 is, the more easily the centrifugal clutch 2 is connected and the more difficult the centrifugal clutch 2 is disconnected. Therefore, the intermittent timing of the centrifugal clutch 2 can be adjusted by adjusting the elastic force of the output side offspring 71.

  A plurality of cam surfaces 69 a are formed on the surface of the roller retainer 69 opposite to the plate group 66. The plurality of cam surfaces 69a are located inside the plate group 66 in the radial direction. The plurality of cam surfaces 69 a are arranged radially about the axis AX of the main shaft 33. Each cam surface 69a extends outward in the vehicle width direction as it goes outward in the radial direction.

-Output side retainer 72-
An output side retainer 72 is attached to the shaft 68. The output side retainer 72 is attached to the shaft 68 so that it cannot rotate and cannot be displaced in the axial direction of the axis AX. The output side retainer 72 faces the surface of the roller retainer 69 opposite to the plate group 66. In other words, the output side retainer 72 faces the cam surface 69a. The output side retainer 72 and the cam surface 69a of the roller retainer 69 form a space 70 that becomes narrower as the distance from the axis AX increases.

  Specifically, the output side retainer 72 includes a spring stopper plate 73 and a spring 74. The spring stopper plate 73 is fixed to the shaft 68.

  Specifically, the spring 74 includes two annular belt springs 74a and 74b. The disc spring 74a extends outward in the vehicle width direction toward the outer side in the radial direction. A radially outer end of the disc spring 74 a is abutted against the spring stopper plate 73. The inner end of the disc spring 74b is in contact with the inner end of the disc spring 74a. The disc spring 74b extends inward in the vehicle width direction toward the outer side in the radial direction. The space 70 is formed by the disc spring 74b and the cam surface 69a. A collar washer 76 is disposed between the spring 74 and the shaft 68. By this color washer 76, a direct collision between the shaft 68 and the spring 74 is suppressed.

  In addition, by using the disc springs 74a and 74b as the spring 74 as in this embodiment, a relatively uniform biasing force can be generated in the circumferential direction. For this reason, the roller retainer 69 can be pressed with a relatively uniform force in the circumferential direction. As a result, the uneven adhesion of the plate group 66 can be reduced in the circumferential direction, and the plate group 66 can be more closely adhered.

~ Output roller weight 42 ~
In the space 70, an output side pressing body 40b is disposed. The output side pressing body 40 b is configured by a plurality of output side roller weights 42. The output-side roller weight 42 turns with the rotation of the shaft 68, and the roller retainer 69 is pressed toward the plate group 66 by the centrifugal force generated at the time of turning, and the spring 74 is pressed outward in the vehicle width direction. However, it moves toward the direction away from the axis AX. Thereby, the roller retainer 69 moves to the plate group 66 side, and the plate group 66 is brought into a pressure contact state.

  The shape of the output-side roller weight 42 is not particularly limited as long as it turns with the rotation of the shaft 68 and is movable inward and outward in the radial direction. Specifically, in this embodiment, the output side roller weight 42 is formed in a substantially cylindrical shape.

  More specifically, the output side roller weight 42 is divided into a central portion and both side portions with respect to the axial direction of the output side roller weight 42. Both side portions cannot rotate with respect to each other. On the other hand, the central portion is rotatable with respect to both side portions. The cam surface 69a is formed so as to contact only the central portion. In other words, only the central portion that contacts the cam surface 69a can rotate with respect to the other portions. By doing so, the sliding friction between the cam surface 69a and the output side roller weight 42 can be reduced. As a result, wear of the output side roller weight 42 can be suppressed.

-Pressure plate 77 and roller retainer 78-
A pressure plate 77 as a pressure member is disposed on the right side in the vehicle width direction with respect to the plate group 66. The pressure plate 77 is non-rotatably attached to the outer ring 75b of the bearing 75. The outer end in the radial direction of the pressure plate 77 is engaged with a plurality of arms 46d shown in FIG. As a result, the pressure plate 77 cannot rotate with respect to the clutch housing 46. In other words, the pressure plate 77 rotates with the clutch housing 46. On the other hand, the pressure plate 77 can be displaced with respect to the clutch housing 46 in the axial direction of the axis AX.

  Between the pressure plate 77 and the clutch housing 46, a plurality of input-side off springs 79 as input-side urging members are arranged at equal intervals along the circumferential direction of the clutch housing 46. Specifically, the plurality of input-side off springs 79 are disposed in the respective gaps 46i of the pair of arms 46d shown in FIG. The input-side off spring 79 is configured by a compression coil spring. The pressure plate 77 is urged toward the outside in the vehicle width direction by the input side offspring 79. That is, the pressure plate 77 is urged in the direction away from the plate group 66 by the input-side off spring 79.

  As described above, in this embodiment, the pressure plate 77 as the pressure member indirectly presses the roller retainer 69 via the bearing 75 and the shaft 68. Thereby, the pressure plate 77 indirectly presses the plate group 66.

  The pressure plate 77 as a pressure member indirectly presses the plate group 66 from the same direction as the direction in which the roller retainer 69 presses the plate group 66.

  A roller retainer 78 is arranged outside the pressure plate 77 in the vehicle width direction. The roller retainer 78 is formed in a ring shape when viewed from the axial direction of the axis AX. The roller retainer 78 faces the surface of the pressure plate 77 opposite to the plate group 66. A plurality of cam surfaces 81 are formed on the surface of the roller retainer 78 on the pressure plate 77 side. The plurality of cam surfaces 81 are arranged radially about the axis AX. Each cam surface 81 is formed so as to extend inward in the vehicle width direction as it goes outward in the radial direction. Thus, a space 82 is formed between each cam surface 81 and the pressure plate 77 and becomes narrower as the distance from the axis line AX increases.

  Similar to the pressure plate 77, the radially outer end 78b of the roller retainer 78 is engaged with a plurality of arms 46d shown in FIG. In other words, the radially outer end of the roller retainer 78 is directly supported by the clutch housing 46. As a result, the roller retainer 78 cannot rotate with respect to the clutch housing 46. In other words, the roller retainer 78 rotates with the clutch housing 46. On the other hand, the roller retainer 78 can be displaced with respect to the clutch housing 46 in the axial direction of the axis AX.

~ Belleville spring 83-
A disc spring 83 as an urging member is disposed on the right side in the vehicle width direction from the roller retainer 78. The disc spring 83 is a kind of leaf spring. The disc spring 83 is formed in an annular shape. The disc spring 83 is provided between the clutch housing 46 and the roller retainer 78. The disc spring 83 extends in a direction inclined with respect to the axis AX direction from the outer end 83b toward the inner end 83a with respect to the centrifugal direction. In other words, the disc spring 83 extends toward the roller retainer 78 from the outer end 83b toward the inner end 83a near the axis AX in the centrifugal direction.

  As shown in FIG. 1, the length of the disc spring 83 in the centrifugal direction is such that the end 83a of the disc spring 83 on the inner side in the centrifugal direction is the input side when the input side roller weight 41 is positioned closest to the axis AX. The length of the roller weight 41 is set so as to be farther from the axis AX than the end of the roller weight 41 near the axis AX.

  As will be described later, the distal end 83 b of the disc spring 83 in the centrifugal direction is directly fixed to the clutch housing 46 by a spring stopper 84 and a circlip 85. On the other hand, the distal end 83 a of the disc spring 83 in the centrifugal direction is in direct contact with the roller retainer 78. For this reason, the disc spring 83 urges the roller retainer 78 directly inward in the direction of the axis AX with the end 83a on the inner side in the centrifugal direction.

  The roller retainer 78 is urged inward in the vehicle width direction by a disc spring 83 which is a kind of plate spring. In other words, the roller retainer 78 is urged toward the plate group 66 by the disc spring 83.

  As shown in FIG. 5, the ring-shaped spring stopper 84 has a plurality of openings 84 a arranged in the circumferential direction. An arm 46d (see FIG. 4) of the clutch housing 46 is inserted into the opening 84a. Thereby, the deformation of the arm 46d of the clutch housing 46 is suppressed.

  The disc spring 83 is in contact with the radially inner portion of the spring stopper 84. On the other hand, the radially outer portion of the spring stopper 84 is in contact with an end face 46h formed on the arm 46d. Thus, the spring stopper 84 is prevented from moving to the left in the vehicle width direction from the end face 46h.

  As shown in FIG. 6, the circlip 85 is formed in a ring shape with a part cut away. The circlip 85 is fitted in a linear groove 46g (see FIG. 4) formed in the arm 46d. Thereby, the movement of the circlip 85 in the axial direction of the axis AX is restricted, and the movement of the spring stopper 84 is also restricted. That is, the spring stopper 84 is fixed by the circlip 85 and the end face 46h formed on the arm 46d in the axial direction of the axis AX. As a result, the radially outer end of the disc spring 83 is fixed in the axial direction of the axis AX. Thus, according to the fixing method of the disc spring 83 using the circlip 85, the disc spring 83 can be easily fixed. And the disc spring 83 can be removed easily.

  As described above, the roller retainer 78 is biased toward the plate group 66 by the disc spring 83 in the axial direction of the axis AX. The biasing force of the disc spring 83 biases the shaft 68 to which the output side retainer 72 is attached to the plate group 66 side via the input side roller weight 41 and the pressure plate 77. Therefore, the output side retainer 72 is also urged toward the plate group 66 by the disc spring 83 in the axial direction of the axis AX.

  As will be described in detail later, in this embodiment, as shown in FIGS. 1 and 10, the support portion 78 a that supports the disc spring 83 of the roller retainer 78 is a roller retainer 78 supported by the clutch housing 46. It is located in the vehicle width direction right side rather than the outer side edge part 78b. For this reason, as shown in FIG. 10, when the pressure plate 77 is located on the rightmost side in the vehicle width direction, the disc spring 83 has a radially inner end 83a of the disc spring 83 that is closer to the vehicle than the outer end 83b. Deforms until it is located on the right side in the width direction.

~ Input side roller weight 41 ~
In the space 82, an input side pressing body 40a is disposed. The input side pressing body 40 a is configured by a plurality of input side roller weights 41. The input side roller weight 41 is located farther from the plate group 66 than the output side roller weight 42 in the axial direction of the axis AX. That is, the input side roller weight 41 is located on the right side of the output side roller weight 42 in the axial direction of the axis AX. Further, the input side roller weight 41 is located farther from the axis line AX than the output side roller weight 42 in the radial direction perpendicular to the axis line AX. As described above, the input-side roller weight 41 and the output-side roller weight 42 are disposed obliquely with respect to the axis AX, thereby suppressing positional interference between the input-side roller weight 41 and the output-side roller weight 42. Can do. As a result, the centrifugal clutch 2 can be made compact.

  The input side roller weight 41 turns with the rotation of the clutch housing 46, and the pressure plate 77 is pressed toward the plate group 66 by the centrifugal force generated at the time of turning, and the spring 74 is moved outward in the vehicle width direction. While pressing, it moves in a direction away from the axis AX. Thereby, the roller retainer 69 moves to the plate group 66 side, and the plate group 66 is brought into a pressure contact state.

  The shape of the input-side roller weight 41 is not particularly limited as long as it turns with the rotation of the shaft 68 and is movable inward and outward in the radial direction. Specifically, in this embodiment, the input side roller weight 41 is formed in a substantially cylindrical shape.

  More specifically, the input side roller weight 41 is divided into a central portion and both side portions with respect to the axial direction of the input side roller weight 41. Both side portions cannot rotate with respect to each other. On the other hand, the central portion is rotatable with respect to both side portions. The cam surface 81 is formed so as to contact only the central portion. In other words, only the central portion that contacts the cam surface 81 is rotatable with respect to the other portions. By doing so, the sliding friction between the cam surface 81 and the input side roller weight 41 can be reduced. As a result, the wear of the input side roller weight 41 can be suppressed.

-Weight of input side roller weight 41 and output side roller weight 42-
In the present embodiment, the total weight of the plurality of output side roller weights 42 is set to be heavier than the total weight of the plurality of input side roller weights 41. For example, the same number of output side roller weights 42 and input side roller weights 41 are provided, and the weight per output side roller weight 42 is set to be heavier than the weight per input side roller weight 41. May be. The weight per output-side roller weight 42 and the weight per input-side roller weight 41 may be substantially the same, and more output-side roller weights 42 may be provided than the input-side roller weight 41. Further, the output side roller weight 42 may be provided more than the input side roller weight 41, and the weight per output side roller weight 42 may be set to be heavier than the weight per input side roller weight 41.

-Biasing force of input-side offspring 79 and output-side offspring 71-
In the present embodiment, the total biasing force of the plurality of output-side offsprings 71 is set to be weaker than the total biasing force of the plurality of input-side offsprings 79. Thus, by setting the total weight of the plurality of output side roller weights 42 and the plurality of input side roller weights 41 and the total biasing force of the plurality of output side offsprings 71 and the input side offsprings 79, the output side rollers The rotational speed of the clutch boss 48 at which the weight 42 starts moving in the centrifugal direction is set lower than the rotational speed of the clutch housing 46 at which the input side roller weight 41 starts moving in the centrifugal direction.

  Specifically, the same number of output-side offsprings 71 and input-side offsprings 79 are provided, and the biasing force of each output-side offspring 71 is set to be weaker than the biasing force of each input-side offspring 79. May be. The urging force of each output-side off-spring 71 and the urging force of each input-side off-spring 79 may be substantially the same, and more output-side off-springs 71 than the input-side off-spring 79 may be provided. Further, the output-side offsprings 71 may be provided more than the input-side offsprings 79, and the urging force of each output-side offspring 71 may be set to be weaker than the urging force of each input-side offspring 79.

-Clutch release mechanism 86-
The centrifugal clutch 2 of the present embodiment is provided with a clutch release mechanism 86 as a pressure release mechanism. The clutch release mechanism 86 forcibly releases the pressure contact state of the plate group 66 by the force applied from the rider of the motorcycle 1. The clutch release mechanism 86 enables the centrifugal clutch 2 to be disconnected by the rider of the motorcycle 1.

  In this embodiment, the rider of the motorcycle 1 operates a clutch operating means such as a clutch lever or a clutch pedal (not shown), so that a force applied to the clutch lever or the clutch pedal is applied to the clutch release mechanism 86. An example in which the pressure contact state of the plate group 66 is forcibly released will be described. However, the present invention is not limited to this. For example, when a rider of the motorcycle 1 operates a clutch lever or a clutch pedal (not shown), a drive mechanism such as a separately provided oil pump is operated, and the force generated by the oil pump is applied to the clutch release mechanism 86. The pressure contact state of the plate group 66 may be forcibly released.

  The clutch release mechanism 86 includes a push rod 43 shown in FIGS. 1 and 2 and a push rod drive mechanism 87 shown in FIGS. 2 and 7. As shown in FIG. 1, the push rod 43 is disposed inside the main shaft 33 and inside a through hole 33 a formed inside the main shaft 33 so as to penetrate in the axial direction of the axis AX. The through hole 33a also serves as an oil supply hole for supplying oil to each sliding portion of the centrifugal clutch 2. Specifically, oil is supplied to each sliding portion of the centrifugal clutch 2 through a gap 89 between the inner wall of the through hole 33 a and the push rod 43.

  The push rod 43 includes a short push rod 43a and a long push rod 43b. The short push rod 43a is disposed relatively outside in the vehicle width direction. The right end of the short push rod 43 a is in contact with the shaft 68. An O-ring 88 is attached to a substantially central portion in the axial direction of the short push rod 43a. Thereby, the oil supplied through the gap 89 is suppressed from reaching the right side in the vehicle width direction from the O-ring 88. Further, by providing the O-ring 88, the short push rod 43a rotates with the main shaft 33. On the other hand, the long push rod 43 b does not rotate with the main shaft 33. For this reason, when the main shaft 33 rotates, the short push rod 43a rotates relative to the long push rod 43b. In view of this, the end surface of the short push rod 43a on the long push rod 43b side is formed as a curved surface protruding toward the long push rod 43b. Thereby, the sliding resistance between the short push rod 43a and the long push rod 43b when the short push rod 43a rotates is reduced.

  As shown in FIGS. 2 and 7, the left end of the long push rod 43 b is located on the left side of the left end of the main shaft 33 and reaches the push rod drive mechanism 87. FIG. 7 is a sectional view showing the push rod drive mechanism 87. The portion above the axis AX in FIG. 7 represents a state where the clutch release mechanism 86 is not driven. In other words, the portion below the axis AX in FIG. 7 represents a state in which the push rod 43 is located on the relatively left side and the shaft 68 is not displaced to the right side by the push rod 43. On the other hand, the portion above the axis AX in FIG. 7 represents a state where the clutch release mechanism 86 is driven. In other words, the part above the axis AX in FIG. 7 represents a state in which the push rod 43 is located on the relatively right side and the shaft 68 is displaced to the right side by the push rod 43.

  As shown in FIG. 7, the push rod drive mechanism 87 includes a cylinder 90 and a piston 91. The piston 91 is slidable in the axial direction of the axis AX with respect to the cylinder 90. The piston 91 is attached to the long push rod 43b. For this reason, when the piston 91 slides, the long push rod 43b also moves in the axial direction of the axis AX.

  As described above, the clutch release mechanism 86 is a mechanism for forcibly disconnecting the centrifugal clutch 2 when the centrifugal clutch 2 is engaged. Therefore, the clutch release mechanism 86 is normally used when the engine 4 rotates at high speed. For example, as shown in FIG. 10, the clutch release mechanism 86 is used when both of the two types of roller weights 41 and 42 are located outside in the centrifugal direction. When the clutch release mechanism 86 is driven in a state where both of the two types of roller weights 41 and 42 are located on the outer side in the centrifugal direction, the pressure plate 77 and the roller retainer 78 are moved further to the right in the vehicle width direction by the push rod 43. To do. Therefore, the state shown in FIG. 10 in which the clutch release mechanism 86 is driven in a state where both of the two types of roller weights 41 and 42 are located on the outer side in the centrifugal direction is the state in which the roller retainer 78 has moved to the right in the vehicle width direction. It becomes.

  In the present embodiment, since the support portion 78a of the roller retainer 78 is located on the left side in the vehicle width direction with respect to the outer end portion 78b, as shown in FIG. 10, the roller retainer 78 is most moved to the right side in the vehicle width direction. Then, the disc spring 83 is in a so-called reverse sliding state. Specifically, in a state where no stress is applied, the disc spring 83 in which the inner end 83a in the radial direction is located on the left side in the vehicle width direction with respect to the outer end 83b, the inner end 83a is the outer end 83b. It is deformed until it is located on the right side in the vehicle width direction.

  A working chamber 92 is defined between the piston 91 and the cylinder 90. The working chamber 92 is filled with oil. When the rider of the motorcycle 1 operates the clutch lever or the clutch pedal, the internal pressure in the working chamber 92 increases. As a result, the piston 91 and the long push rod 43b are displaced to the right. Therefore, as shown in FIG. 10, the shaft 68, the pressure plate 77 attached to the shaft 68, and the output side retainer 72 are also displaced to the right. As a result, the roller retainer 69 is displaced to the right, and the pressure contact state of the plate group 66 is released.

  A compression coil spring 93 is disposed between the piston 91 and the crankcase 31. The piston 91 is urged to the left by the compression coil spring 93. That is, the push rod 43 is displaced to the left side and is biased in the direction in which the centrifugal clutch 2 is connected. Thereby, when the operation of the clutch lever or the clutch pedal is released by the rider of the motorcycle 1, the push rod 43 is reliably moved to the left side.

  For example, when the compression coil spring 93 is not provided, even if the operation of the clutch lever or the clutch pedal is released, the situation where the push rod 43 is still located on the right side can be considered. In such a situation, for example, if the engine 4 is stopped and the centrifugal clutch 2 is not connected, the push rod 43 cannot be moved further to the right side. The lever or clutch pedal cannot be operated. Therefore, for example, when the motorcycle 1 cannot start the engine 4 unless the clutch lever or the clutch pedal is operated, the engine 4 cannot be started.

  On the other hand, in the motorcycle 1 according to this embodiment, since the compression coil spring 93 is arranged as described above, even if the operation of the clutch lever or the clutch pedal is released, the push rod 43 is still positioned on the right side. Occurrence of the situation is suppressed. Therefore, when the engine 4 is stopped, the rider of the motorcycle 1 can always operate the clutch lever or the clutch pedal.

  As described above, in this embodiment, the pressure plate 77 as the pressure member indirectly presses the plate group 66 from the same direction as the direction in which the roller retainer 69 presses the plate group 66.

  For example, when the pressure plate 77 and the roller retainer 69 press the plate group 66 from opposite directions, the position of the pressure plate 77 when the centrifugal clutch 2 is disconnected depends on the position of the roller retainer 69 in the axial direction of the axis AX. The position is different. Specifically, for example, when the roller retainer 69 is located on the relatively right side with respect to the axial direction of the axis AX, the centrifugal clutch 2 is not disconnected unless the pressure plate 77 is displaced to the right side. On the other hand, for example, when the roller retainer 69 is located on the relatively left side with respect to the axial direction of the axis AX, the centrifugal clutch 2 is disconnected without displacing the pressure plate 77 to the right side. For this reason, when the pressure plate 77 and the roller retainer 69 press the plate group 66 from opposite directions, the push rod 43 when the centrifugal clutch 2 is disconnected depends on the position of the roller retainer 69 in the axial direction of the axis AX. The position of is different.

  On the other hand, when the pressure plate 77 and the roller retainer 69 are arranged on the same side with respect to the plate group 66 as in this embodiment, the position of the push rod 43 when the centrifugal clutch 2 is disconnected. Is constant.

(Operation of centrifugal clutch 2)
Next, the operation of the centrifugal clutch 2 will be described with reference to FIGS. 1 and 8 to 10. 8 to 10 show only a cross section of a portion on one side of the axial line AX of the centrifugal clutch 2 in view of the fact that the centrifugal clutch 2 is rotationally symmetric with respect to the axial line AX.

-When the centrifugal clutch 2 is connected-
The portion above the axis AX of the centrifugal clutch 2 shown in FIG. 1 shows a state where the engine 4 is idling and the centrifugal clutch 2 is not connected. On the other hand, the portion below the axis AX of the centrifugal clutch 2 shown in FIG. 1 shows a state immediately after the rotational speed of the crankshaft 32 is increased and the centrifugal clutch 2 is connected.

  When the engine 4 is started and in an idling state, the clutch housing 46 is rotating together with the crankshaft 32. However, the rotational speed of the clutch housing 46 is relatively slow. For this reason, the centrifugal force acting on the input side roller weight 41 is relatively small. Therefore, the input side roller weight 41 is located relatively inside. Therefore, the pressure plate 77, the shaft 68, and the output side retainer 72 are located on the relatively right side by the urging force of the input side offspring 79. In the idling state, the main shaft 33 does not rotate or has a relatively low rotational speed. Therefore, the centrifugal force acting on the output side roller weight 42 is relatively small. Therefore, the output side roller weight 42 is located relatively inside. Therefore, the roller retainer 69 is located on the relatively right side by the biasing force of the output side offspring 71. As a result, the distance between the roller retainer 69 and the bottom 46a of the clutch housing 46 is relatively wide, and the plate group 66 is in a non-pressure contact state. Therefore, the rotation of the clutch housing 46 is not transmitted to the clutch boss 48.

  As the rotational speed of the crankshaft 32 becomes relatively high, the rotational speed of the clutch housing 46 also becomes relatively high. As the rotational speed of the clutch housing 46 increases, the centrifugal force acting on the input side roller weight 41 increases. As a result, the input side roller weight 41 moves outward. Therefore, the pressure plate 77 is pressed to the left by the input side roller weight 41. As a result, the pressure plate 77, the shaft 68, and the output side retainer 72 move to the left against the urging force of the input side offspring 79. As a result, the roller retainer 69 also moves to the left side against the urging force of the output side offspring 71 via the output side roller weight 42. That is, the roller retainer 69 also moves to the plate group 66 side. As a result, the plate group 66 is brought into a pressure contact state, and the centrifugal clutch 2 is connected. The mode at that time is shown in the lower part of the axis AX in FIG.

  When the centrifugal clutch 2 is connected, the rotation of the clutch housing 46 is transmitted to the clutch boss 48 via the plate group 66. As a result, the clutch boss 48 rotates together with the clutch housing 46. When the clutch boss 48 starts to rotate, the output side roller weight 42 turns accordingly. Therefore, the centrifugal force acting on the output side roller weight 42 is increased. As a result, the output side roller weight 42 moves to the outside in the centrifugal direction. FIG. 8 shows the state at that time.

  As shown in the lower part of the axis AX in FIG. 1, the centrifugal clutch 2 is configured such that the centrifugal clutch 2 is connected when only the input side roller weight 41 moves outside in the centrifugal direction. That is, the centrifugal clutch 2 is configured such that the plate group 66 is in a press-contact state when only the input side roller weight 41 moves outward in the centrifugal direction. Therefore, the roller retainer 69 cannot be substantially displaced further to the left from the state where only the input side roller weight 41 has moved to the outside in the centrifugal direction. Therefore, even if the output side roller weight 42 further moves outward in the centrifugal direction from that state, the roller retainer 69 cannot be substantially displaced toward the plate group 66, and accordingly, as shown in FIG. 74 and the disc spring 83 are deformed. Therefore, in the centrifugal clutch 2 according to this embodiment, the capacity of the centrifugal clutch 2 is determined by the elastic force of the disc spring 83.

-When the centrifugal clutch 2 is disconnected-
Next, a case where the centrifugal clutch 2 is disconnected will be described. In the state where the centrifugal clutch 2 shown in FIG. 8 is connected, when the rotational speed of the crankshaft 32 is slowed down, the centrifugal force acting on the input side roller weight 41 and the output side roller weight 42 becomes small. Here, in this embodiment, as described above, the rotational speed of the clutch boss 48 at which the output side roller weight 42 starts moving in the centrifugal direction is set lower than the rotational speed of the input side roller weight 41. . That is, when the clutch housing 46 and the clutch boss 48 rotate as a unit, the input side roller weight 41 first moves inward in the centrifugal direction when the rotational speed is low. However, the output side roller weight 42 does not immediately move inward in the centrifugal direction. For this reason, even if the rotational speed of the crankshaft 32 becomes low, the centrifugal clutch 2 is not immediately disconnected. Since the centrifugal clutch 2 is connected, the engine brake acts. Thereby, the rotation of the main shaft 33 is gradually slowed down. Accordingly, the centrifugal force acting on the output side roller weight 42 is gradually reduced. When the rotation speed of the main shaft 33 becomes a predetermined rotation speed or less, the output side roller weight 42 also moves inward in the centrifugal direction. As a result, the roller retainer 69 moves to the right and the centrifugal clutch 2 is disconnected.

  That is, in the centrifugal clutch 2 according to the present embodiment, even when the rotational speed of the crankshaft 32 is low, the connected state of the centrifugal clutch 2 is maintained when the rotational speed of the main shaft 33 is relatively high. Even if the rotational speed of the clutch housing 46 is reduced to a rotational speed at which the input side roller weight 41 moves inward in the centrifugal direction, the centrifugal clutch 2 has the rotational speeds of the clutch housing 46 and the clutch boss 48 set to the output side roller. The weight 42 is in a connected state until the rotational speed is reduced to the rotational speed at which it moves inward in the centrifugal direction.

Specifically,
Rotational speed at which the input side roller weight 41 moves inward in the centrifugal direction: r ₁ ,
Rotational speed at which the output roller weight 42 moves inward in the centrifugal direction: r ₂ ,
Then, in this embodiment,
r ₁ > r ₂ (1)
It becomes.

For example, the output side roller weight 42 is not provided, if the pressure plate 77 presses the direct plate group 66, the centrifugal clutch 2 is disconnected when the rotational speed of the clutch housing 46 is reduced to r ₁ The

On the other hand, in the present embodiment in which the output side roller weight 42 is provided, the centrifugal clutch 2 is not disconnected until the rotational speed of the clutch housing 46 becomes r ₂ lower than r ₁ . That is, the connected state of the centrifugal clutch 2 is maintained until the rotational speed of the clutch housing 46 becomes relatively low. As a result, the engine brake can be operated even in a relatively low engine speed range.

Further, for example, when the engine 4 is in an idling state and the rotation speed of the main shaft 33 is relatively high although the rotation speed of the crankshaft 32 is relatively low, as shown in FIG. Only 42 moves outside in the centrifugal direction. As a result, the roller retainer 69 is pressed to the left and the plate group 66 is pressed. As a result, the centrifugal clutch 2 is connected as shown in FIG. When the centrifugal clutch 2 is connected, the clutch housing 46 also rotates together with the clutch boss 48. The rotation of the clutch housing 46 is transmitted to the crankshaft 32, and the engine brake acts. Thereby, the rotational speed of the centrifugal clutch 2 and the main shaft 33 is reduced. When the rotational speeds of the main shaft 33 and the centrifugal clutch ₂ are lower than the rotational speed r2, the centrifugal clutch 2 is disconnected.

  Thus, in this embodiment, even if the rotational speed of the crankshaft 32 is relatively slow, the centrifugal clutch 2 is connected when the rotational speed of the main shaft 33 is relatively high. As a result, the engine brake can be applied until the rotation speed of the main shaft 33 becomes slow.

  This effect can be obtained even when the rotational speed at which the output side roller weight 42 moves inward in the centrifugal direction is higher than the rotational speed of the input side roller weight 41.

(Function and effect)
As described above, in the present embodiment, the disc spring 83 which is a kind of leaf spring is used as a means for biasing the roller retainer 78. In addition, the outer end 83 b of the disc spring 83 is fixed to the clutch housing 46. Therefore, unlike the clutch described in Patent Document 1, it is not necessary to separately provide a receiving member for receiving the biasing force of the disc spring 83 on the outer end 83b side. It is only necessary to provide a fixing member for fixing the disc spring 83 to the clutch housing 46. Specifically, it is sufficient to provide only the spring stopper 84 and the circlip 85.

  For example, as in the clutch described in Patent Document 1, when a compression coil spring is used and a relatively thick end plate is provided as a fixing member, a portion that receives the reaction force of the compression coil spring of the end plate; A portion of the end plate fixed to the clutch housing 46 is relatively far away. For this reason, the rigidity required for the end plate is relatively high. In other words, if the rigidity of the end plate is low, there is a possibility that the portion between the portion of the end plate that receives the reaction force of the compression coil spring and the portion of the end plate that is fixed to the clutch housing 46 is deformed. Therefore, it is necessary to make the end plate relatively thick and heavy.

  On the other hand, when the outer end 83b of the disc spring 83 is directly fixed to the clutch housing 46 by the spring stopper 84 and the circlip 85, the portion receiving the reaction force of the disc spring 83 and the clutch housing 46 are fixed. The part is substantially equal. For this reason, the rigidity required for the spring stopper 84 and the circlip 85 is lower than that in the case of Patent Document 1. Therefore, the centrifugal clutch 2 can be made compact and lightweight.

  Thus, by arranging one end of the disc spring 83 so as to substantially contact the clutch housing 46, the rigidity of the member that receives the reaction force of the disc spring 83 on the one end side is relatively low. can do. As a result, the centrifugal clutch 2 can be made compact and lightweight.

  For example, it is conceivable that the inner end portion 83a of the disc spring 83 is positioned relatively on the right side in the vehicle width direction, and the outer end portion 83b is positioned relatively on the left side in the vehicle width direction. In other words, the disc spring 83 may be arranged so as to extend to the left in the vehicle width direction from the inner end 83a toward the outer end 83b. However, in that case, the outer end 83b needs to be fixed to the clutch housing 46. For this reason, it is necessary to separately provide a fixing member for fixing the outer end 83b to the clutch housing 46. As described above, when the fixing member is separately provided, the portion of the separately provided fixing member that receives the urging force from the disc spring 83 and the attachment portion with respect to the clutch housing 46 are relatively separated from each other. Therefore, relatively high rigidity is required for the fixing member that is separately received. Therefore, it is necessary to make the fixing member relatively thick with relatively high rigidity.

  On the other hand, in this embodiment, the disc spring 83 is arrange | positioned so that it may extend in the vehicle width direction left side from the outer side edge part 83b toward the inner side edge part 83a. For this reason, the outer end 83 b side close to the clutch housing 46 is an attachment portion for the clutch housing 46. Therefore, the spring stopper 84 and the circlip 85 that require only relatively low rigidity can be fixed to the clutch housing 46. As a result, the centrifugal clutch 2 can be made compact and lightweight.

  By the way, it is conceivable that the direction in which the pressure plate 77 presses the plate group 66 and the direction in which the roller retainer 69 presses the plate group 66 are set in opposite directions. That is, it can be considered that the pressure plate 77 is disposed on one side of the plate group 66 while the roller retainer 69 is disposed on the other side of the plate group 66. However, in that case, there arises a problem that variations occur in clutch release points when the centrifugal clutch 2 is disconnected using the clutch release mechanism 86. That is, there arises a problem that the position of the push rod 43 when the centrifugal clutch 2 is disconnected varies. This is because both the position of the plate group 66 at the right end in the vehicle width direction and the position of the left end at the vehicle width direction are not constant. More specifically, when the position of the left end of the plate group 66 in the vehicle width direction changes, the position of the roller retainer 69 in the vehicle width direction when the pressure contact state of the plate group 66 is released also changes. As a result, the position of the push rod 43 in the vehicle width direction when the centrifugal clutch 2 is disconnected changes. Therefore, the clutch release point also changes.

  On the other hand, in the centrifugal clutch 2 according to this embodiment, the pressure plate 77 and the roller retainer 69 are located on the same side with respect to the plate group 66. The pressure plate 77 and the roller retainer 69 press the plate group 66 in the same direction. For this reason, the position of the left end of the plate group 66 in the vehicle width direction is constant. Therefore, the pressure contact state of the plate group 66 is released, and the position of the roller retainer 69 when the centrifugal clutch 2 is disconnected is constant. As a result, the clutch release point is stabilized.

  Incidentally, for example, as in the clutch described in Patent Document 1, it is conceivable to arrange a plurality of compression coil springs arranged in the circumferential direction instead of the disc spring 83. In this case, since the elastic forces of the plurality of compression coil springs are not completely equal to each other, the urging force against the roller retainer 78 varies in the circumferential direction. As a result, there is a possibility that a suitable close state of the plate group 66 cannot be obtained.

  On the other hand, when the disc spring 83 is used as in this embodiment, the urging force against the roller retainer 78 is substantially uniform in the circumferential direction. Therefore, a suitable close state of the plate group 66 is easily obtained. Thereby, the centrifugal clutch 2 with good attachment / detachment performance can be obtained.

  When the disc spring 83 is used as in this embodiment, the size of the movable range of the roller retainer 78 is determined solely by the length of the disc spring 83 in the radial direction. As the length of the disc spring 83 in the radial direction is increased, the movable range of the roller retainer 78 is increased. On the other hand, the rigidity required for the disc spring 83 increases as the length of the disc spring 83 in the radial direction increases. That is, in order to secure a large movable range of the roller retainer 78, the length in the radial direction of the disc spring 83 must be increased, but the rigidity required for the disc spring 83 is increased accordingly. Therefore, it is difficult to ensure the rigidity of the disc spring 83. In other words, when the disc spring 83 is used, it is difficult to secure a large movable range of the roller retainer 78. That is, when the disc spring 83 is used, it is difficult to ensure a large movable range of the pressure member.

  On the other hand, in the present embodiment, the disc spring 83 extends in a direction opposite to the extending direction in the state where the stress of the disc spring 83 is not applied when the push rod 43 is positioned on the rightmost side in the vehicle width direction. A so-called reverse-sliding state in which the disc spring 83 is deformed is obtained. In this manner, by using the disc spring 83 until it is in a so-called reverse-sliding state, the movable range of the outer end portion 83b of the disc spring 83 can be expanded. As a result, the movable range of the roller retainer 78 can be expanded.

  As shown in FIG. 1, the length of the disc spring 83 in the radial direction is such that the inner end 83a is closer to the axis AX of the input side roller weight 41 when the input side roller weight 41 is positioned closest to the axis AX. It is preferable that the length is longer than the end of the axis AX. By doing so, the rigidity required for the disc spring 83 can be further reduced.

<< Modification 1 >>
Hereinafter, modifications of the above embodiment will be described in detail with reference to FIGS. In the following description of the first to fourth modifications, constituent elements having substantially the same functions are described with reference numerals common to the above-described embodiment, and description thereof is omitted.

  In the above-described embodiment, the example in which the output side retainer 72 is configured using the spring 74 has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 11, instead of the output side retainer 72 having the spring 74, a plate 101 having no urging member may be arranged.

  In the example shown in FIG. 11, the radially outer portion of the output side retainer 72 is formed so as to extend to the left as it goes away from the axis AX in the radial direction. As a result, a cam surface 102 is formed that extends to the left as it moves away from the axis AX in the radial direction. As a result, a space 70 is formed in which the width in the direction of the axis AX decreases as the distance from the axis AX increases in the radial direction.

<< Modification 2 >>
FIG. 12 is a cross-sectional view of the clutch according to the second modification. In the present embodiment, a pressure member 110 is disposed instead of the pressure plate 77. The central portion of the pressure member 110 is fixed to the outer ring 75 b of the bearing 75. Thereby, the pressure member 110 is rotatable with respect to the shaft 68 and the main shaft 33.

(Pressure member 110)
As shown in FIG. 15, a protruding portion 116 that protrudes outward in the radial direction is formed on the outer peripheral portion of the pressure member 110. The protrusion 116 engages with the arm 46 d of the clutch housing 46, so that the pressure member 110 is prevented from rotating with respect to the clutch housing 46. Therefore, the pressure member 110 rotates together with the clutch housing 46.

  A plurality of guide portions 115 are formed on the radially outer portion of the pressure member 110. The plurality of guide portions 115 include a first guide portion 115a, a second guide portion 111b, and a third guide portion 115c. The first guide portion 115a, the second guide portion 115b, and the third guide portion 115c constitute a guide portion pair 115d. In the second modification, a total of six guide portion pairs 115d are arranged in the circumferential direction. That is, a total of 18 guide portions 115 are formed.

Direction _{X 1} of extension of the second guide portion 115b is substantially the same as the radial direction. On the other hand, a direction _{X 2} of extension of the first guide portion 115a, and the direction _{X 3} of extension of the third guide portion 115c, differs radially slightly. By arranging the first to third guide portions 115a to 115c in this way, the distance between the radially outer portion of the first guide portion 115a and the radially outer portion of the second guide portion 115b is compared. Narrowly set. The distance between the radially outer portion of the third guide portion 115c and the radially outer portion of the second guide portion 115b is set to be relatively narrow. As a result, the circumferential width of the radially outer portion of the guide portion pair 115d is relatively narrow. Therefore, it is easy to secure a space for forming the rib 118 having a relatively wide outer width in the radial direction between the adjacent guide portion pairs 115d. A screw hole 119 is formed in the radially outer portion of the rib 118 formed relatively wide.

  Each rib 118 is located relatively inward in the radial direction, and is formed so as to be continuous with the rib 117 extending radially from the center C. Thereby, a plurality of ribs extending from the center C to the outer peripheral portion of the pressure member 110 are formed. Therefore, the rigidity of the pressure member 110 is improved. Each rib 118 is formed with a screw hole 119.

  Each guide portion 115 is formed with a cam surface 111. Specifically, the cam surface 111 extends in the direction in which the guide portion 115 extends. The cam surface 111 extends from the middle part of the guide part 115 to the outer end part in the radial direction. The cam surface 111 abuts on a rotatable central portion of the input side roller weight 41. The cam surface 111 is provided so as to protrude from the surface of the guide portion 115.

(Retainer 112)
As shown in FIG. 12, in the second modification, a ring-shaped retainer 112 in a plan view facing the pressure member 110 is disposed. As shown in FIG. 12, the retainer 112 has a flat plate shape in a side view. As shown in FIG. 14, a protrusion 112 c that protrudes outward in the radial direction is formed on the outer periphery of the retainer 112. The protrusion 112c is engaged with the arm 46d of the clutch housing 46, so that the retainer 112 is prevented from rotating with respect to the clutch housing 46. Therefore, the retainer 112 rotates together with the clutch housing 46. On the other hand, the retainer 112 can be displaced in the axial direction of the axis AX.

  As shown in FIGS. 12 and 14, a protrusion 112 b is formed on the radially inner portion of the retainer 112. A plurality of through holes 112a arranged in the circumferential direction are formed in a substantially central portion of the retainer 112 in the radial direction.

  The inner end 112e in the radial direction of the retainer 112 is located on the right side in the axis AX direction with respect to the outer end 112f. For this reason, when the retainer 112 is positioned on the rightmost side in the axis AX direction, the disc spring 113 is in a so-called reverse-sliding state.

(Belleville spring 113)
As shown in FIG. 12, also in the second modification, the outer end portion in the radial direction of the disc spring 113 is related to the axial direction of the axis AX by the spring stopper 84 and the circlip 85 as in the above embodiment. It is fixed to the clutch housing 46.

  As shown in FIG. 13, a plurality of protrusions 113 b that protrude inward in the radial direction are formed at the radially inner end of the disc spring 113. The protrusion 113b is engaged with the recess 112d of the retainer 112 shown in FIG. Thereby, the disc spring 113 and the retainer 112 are being fixed regarding the circumferential direction. In addition, a plurality of through holes 113 a arranged in the circumferential direction are formed in a substantially central portion in the radial direction of the disc spring 113.

(Assembly work of pressure member 110 etc.)
When the clutch according to the second modification is assembled, a screw is passed through the through hole 113a of the disc spring 113 and the through hole 112a of the retainer 112, and the screw is tightened against the screw hole 119 of the pressure member 110. The pressure member 110, the input side roller weight 41, the retainer 112, and the disc spring 113 are integrated. At the same time, the axial width of the axial line AX of the pressure member 110, the input side roller weight 41, the retainer 112, and the disc spring 113 is reduced. In such a state, the integrated pressure member 110, the input side roller weight 41, the retainer 112, and the disc spring 113 are assembled in the clutch housing 46. Thereafter, the spring stopper 84 and the circlip 85 are attached. At this time, since the axial width of the axial line AX of the pressure member 110, the input side roller weight 41, the retainer 112, and the disc spring 113 is kept narrow, the spring stopper 84 and the circlip 85 can be attached relatively easily. Can do. After attaching the spring stopper 84 and the circlip 85, the screw tightened with respect to the screw hole 119 can be removed, and the clutch according to the second modification can be assembled.

<< Modification 3 >>
The third modification is a further modification of the second modification. In the second modification, an example in which two types of roller weights 41 and 42 are provided has been described. However, the present invention is not limited to this. In other words, the two types of roller weights 41 and 42 are not essential. For example, as shown in FIG. 16, only the input side roller weight 41 may be provided, and the pressure member 110 may directly press the plate group 66.

<< Modification 4 >>
The fourth modification is a further modification of the third modification. In the third modification, the example in which the pressure member 110 is pressed by one sheet is described. However, the present invention is not limited to this. As shown in FIG. 17, a plurality of disc springs may be arranged in series between the clutch housing 46 and the retainer 112.

  Specifically, a disc spring 120 in which the inner end is in contact with the inner end in the radial direction of the disc spring 113 and the outer end is directly fixed to the retainer 112 may be further provided. As described above, by arranging a plurality of disc springs in series between the clutch housing 46 and the retainer 112, the movable range of the pressure member 110 can be further widened.

<< Modification 5 >>
The fifth modification is a further modification of the third modification. In the third modification, the example in which the outer end portion in the radial direction of the disc spring 113 is located on the right side in the axis AX direction with respect to the inner end portion has been described. However, the present invention is not limited to this configuration. As shown in FIG. 18, the disc spring 113 may be arranged so that the outer end portion in the radial direction of the disc spring 113 is located on the left side in the axis AX direction with respect to the inner end portion. In this case, in order to fix the inner end portion of the disc spring 113 to the clutch housing 46, the spring stopper 84 must be extended relatively inward in the radial direction. Further, the spring stopper 84 must be made relatively high in rigidity. However, the rigidity of the retainer 112 can be reduced accordingly. As a result, the centrifugal clutch 2 can be reduced in size and weight.

  As described above, one end of the disc spring can be made relatively close to the clutch housing 46 by using the disc spring extending in a direction inclined with respect to the axis AX. As a result, the rigidity of the member in contact with one end of the disc spring relatively close to the clutch housing 46 can be made relatively low. As a result, the centrifugal clutch 2 can be made compact and lightweight.

<< Other modifications >>
In the embodiment described above, the motorcycle 1 that is the so-called motorcycle shown in FIG. 1 has been described as an example of the vehicle in which the present invention is implemented. However, the vehicle according to the present invention is not limited to this. The vehicle according to the present invention may be, for example, an off-road type motorcycle, a scooter or moped, or a straddle-type vehicle such as ATV: All Terrain Vehicle. The vehicle according to the present invention may be a vehicle other than a straddle-type vehicle such as a four-wheel vehicle.

  In the above embodiment, a preferred embodiment in which the present invention is implemented has been described by taking a vehicle including the engine 4 as an example. However, the vehicle according to the present invention does not have to include an engine. For example, the vehicle according to the present invention may include any drive source. For example, the vehicle according to the present invention may include an electric motor or the like as a drive source.

  Moreover, although the example using the water-cooled four-cycle parallel four-cylinder engine 4 has been described in the above embodiment, the type of the engine is not particularly limited in the present invention.

  In the present invention, the driving force transmission mechanism that transmits the power from the power unit 3 to the rear wheel 19 is not limited to the chain 25. The driving force transmission mechanism may be, for example, a drive shaft, a belt, or the like.

  In the above embodiment, an example in which the clutch housing 46 constitutes the input side clutch member 44 and the clutch boss 48 constitutes the output side clutch member 47 has been described. However, the present invention is not limited to this configuration. For example, the clutch housing 46 may constitute the output side clutch member 47, and the clutch boss 48 may constitute the input side clutch member 44.

  When a rider of the motorcycle 1 operates a clutch lever or a clutch pedal (not shown), a drive mechanism such as an oil pump is operated, and a force generated by the oil pump is applied to the clutch release mechanism 86 to press the plate group 66 against pressure. The state may be forcibly released.

<< Definition of terms etc. in this specification >>
“Motorcycle” means not only a so-called motorcycle in a narrow sense but also a motorcycle in a broad sense including off-road vehicles, scooters, mopeds, and the like.

  The present invention is useful for a vehicle such as a motorcycle.

It is sectional drawing of the clutch which implemented this invention. It is a schematic block diagram of the power unit using the clutch shown in FIG. Fig. 3 is a left side view of a motorcycle using the power unit shown in Fig. 2. It is the perspective view seen from the upper diagonally upper side of the clutch housing. It is a top view of a spring stopper. It is a top view of a circlip. It is sectional drawing showing a push rod drive mechanism. FIG. 4 is a cross-sectional view of the clutch in a state where the clutch is connected and the main shaft is also rotating at a relatively high speed. FIG. 6 is a cross-sectional view of the clutch at the moment when the rotation speed of the main shaft becomes relatively high in a state where the rotation speed of the crankshaft is relatively low. It is sectional drawing showing the state by which the clutch was forcedly cut | disconnected by the clutch release mechanism. FIG. 9 is a cross-sectional view of a centrifugal clutch according to modification example 1; FIG. 10 is a cross-sectional view of a centrifugal clutch according to modification example 2. 10 is a plan view of a disc spring in Modification 2. FIG. It is a top view of the plate in the modification 2. It is a top view of the pressure member in the modification 2. FIG. 10 is a cross-sectional view of a centrifugal clutch according to modification example 3. It is sectional drawing of the centrifugal clutch which concerns on the modification 4. FIG. 10 is a cross-sectional view of a centrifugal clutch according to modification example 5. 2 is a cross-sectional view of a centrifugal clutch described in Patent Document 1. FIG.

Explanation of symbols

1 Vehicle (motorcycle)
2 Centrifugal clutch
40a Pressing body (input-side pressing body)
46 Clutch housing
48 Clutch boss
64 Friction plate
65 Clutch plate
66 plates
77 Pressure member (pressure plate)
78 Retainer (Roller retainer)
78a support part
78b outer edge
82 spaces
83 Disc spring (leaf spring)
83a Inner end (the other end)
83b Outer end (one end)
86 Clutch release mechanism 120 Belleville spring (another leaf spring)
AX axis

Claims (10)

A clutch housing that rotates about an axis;
A clutch boss that is disposed inside the clutch housing and rotates about the axis;
A plate group comprising: a friction plate that rotates together with the clutch housing; and a clutch plate that faces the friction plate so as to be displaceable in the axial direction of the axis and rotates together with the clutch boss;
It is arranged on one side of the plate group and rotates together with the clutch housing, while being displaceable in the axial direction of the axis, and by displacing to the other side with respect to the axial direction of the axis, directly or indirectly A pressure member that presses the plate group to bring the plate group into a pressure contact state; and
While facing the one side surface of the pressure member and rotating together with the clutch housing, the pressure member is supported directly or indirectly by the clutch housing so as to be displaceable in the axial direction of the axis, and together with the pressure member, the axis A retainer that forms a space that becomes narrower as you move away from it,
One side of the retainer is provided between the clutch housing and the retainer, and extends in a direction inclined with respect to the axial direction from one end to the other end with respect to the centrifugal direction. A leaf spring that biases the retainer to the other side directly or indirectly with the other end while the one end is fixed directly or indirectly to the clutch housing;
It is arranged in a space between the pressure member and the retainer, swivels around the axis along with the rotation of the clutch housing, and presses the pressure member to the other side by the centrifugal force generated during the swiveling, A pressing body that moves outward in the centrifugal direction;
A clutch release mechanism that presses the pressure member toward the one side to release the pressure contact state of the plate group;
Centrifugal clutch with The centrifugal clutch according to claim 1, wherein
The said leaf | plate spring is a centrifugal clutch which is a disc spring formed in the shape of a ring zone. The centrifugal clutch according to claim 1 or 2,
The centrifugal clutch, wherein the other end of the leaf spring is closer to the axis and closer to the retainer than the one end. The centrifugal clutch according to claim 1, wherein
The said leaf | plate spring is a centrifugal clutch which deform | transforms until the other edge part of the said leaf | plate spring is located in one side rather than one edge part, when the said pressure member is located in the most one side. The centrifugal clutch according to claim 1, wherein
The other end of the leaf spring is supported by the retainer;
The portion of the retainer that supports the other end of the leaf spring is located on one side of the retainer that is directly or indirectly supported by the clutch housing. The centrifugal clutch according to claim 1, wherein
The end of the leaf spring near the axis is farther from the axis than the end of the pressing body near the axis when the pressing body is positioned closest to the axis in the centrifugal direction. clutch. The centrifugal clutch according to claim 1, wherein
One end is fixed directly or indirectly to the retainer with respect to the axial direction of the axis, while the other end is fixed directly or indirectly to one end of the leaf spring. A centrifugal clutch further provided with another leaf spring. The centrifugal clutch according to claim 1, wherein
The said leaf | plate spring is a centrifugal clutch which deform | transforms until the other edge part of the said leaf | plate spring is located in one side rather than one edge part, when the said pressure member is located in the most one side. The centrifugal clutch according to claim 1, wherein
The end of the leaf spring near the axis is farther from the axis than the end of the pressing body near the axis when the pressing body is positioned closest to the axis in the centrifugal direction. clutch.   A vehicle comprising the centrifugal clutch according to claim 1.

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