Pulley device and centrifugal clutch

Abstract

To provide a pulley device capable of smoothly actuating a cam mechanism displacing a moving side driven plate as a moving sheave, and a centrifugal clutch equipped with the pulley device.SOLUTION: A pulley device 130 is equipped with a sliding sleeve 153 between a fixed side driven plate 140 and a moving side driven plate 150 which are rotation-driven by driving force of an engine. The fixed side driven plate 140 is formed with a groove-shaped recessed cam portion 144 on a fixed side sleeve 142 formed into a cylindrical shape. In the moving side driven plate 150, a sliding sleeve 153 is fitted with a moving side sleeve 152 formed into a cylindrical shape. The sliding sleeve 153 is formed into a cylindrical shape, and is fitted with an outer peripheral portion of the fixed side sleeve 142 and an inner peripheral portion of the moving side sleeve 152. The sliding sleeve 153 is formed with a projecting cam portion 154 slidably fitted with the recessed cam portion 144.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pulley device for transmitting driving force from a driving source such as an engine, and a centrifugal clutch provided with the pulley device.

Background Art

[0002] Conventionally, there has been a pulley device for transmitting driving force from a driving source such as an engine. For example, Patent Document 1 below discloses a centrifugal clutch including a pulley device composed of a pair of fixed sheaves and a movable sheave that receives driving force from an engine via a belt. In this case, the movable sheave is configured to approach or separate from the fixed sheave by fitting a cylindrical movable boss formed in a cylindrical shape into a cylindrical fixed boss formed in the fixed sheave via a cylindrical sliding member. And the movable sheave obtains an axial thrust by meshing a spiral cam portion formed at the tip of the movable boss with a spiral cam receiving member provided on a drive plate that is integrally rotationally driven by the fixed sheave.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] However, in the pulley device described in Patent Document 1 above, since the movable sheave reciprocally slides on the fixed boss via the sliding member, when there is a deviation between the axial direction of the sliding member and the axial direction of the movable boss, useless frictional resistance occurs between the cam portion formed on the movable sheave and the cam receiving member provided on the drive plate, preventing smooth displacement.

[0005] The present invention has been made to address the above problems, and an object thereof is to provide a pulley device capable of smoothly operating a cam mechanism for displacing a movable side driven plate as the movable sheave, and a centrifugal clutch provided with the pulley device.

Summary of the Invention

[0006] To achieve the above object, the features of the present invention are as follows: a fixed-side driven plate having a fixed-side plate that projects radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receiving a driving force from a drive source via a belt, and rotationally driving; a movable-side driven plate having a movable-side plate that projects radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiching the belt together with the fixed-side plate, receiving a driving force from the drive source via the belt, and rotationally driving while approaching or separating from the fixed-side plate; formed in a cylindrical shape provided between the fixed-side sleeve and the movable-side sleeve 、 a sliding sleeve that is displaced integrally with the movable-side sleeve and slides relative to the fixed-side sleeve, a concave cam portion formed by helically notching along the axial direction on one of the sliding sleeve and the fixed-side sleeve, and a convex cam portion slidably fitted into the concave cam portion on the other of the sliding sleeve and the fixed-side sleeve; on the outer peripheral surface of The concave cam portion or convex cam portion formed on the sliding sleeve is formed to extend axially at one end. 、 According to the features of the present invention configured as described above, in the pulley device, a concave cam portion or convex cam portion that meshes with a convex cam portion or concave cam portion formed on the fixed-side sleeve is formed on the cylindrical sliding sleeve that is displaced integrally with the movable-side sleeve relative to the fixed-side sleeve, and this sliding sleeve directly slides and displaces relative to the fixed-side sleeve. Thereby, according to the pulley device according to the present invention, the cam mechanism composed of the convex cam portion and the concave cam portion can be operated smoothly. Further, according to the pulley device according to the present invention, by forming the concave cam portion or convex cam portion on the sliding sleeve, the number of parts can be reduced, and the pulley device can be miniaturized, lightened, and the manufacturing burden can be reduced. a cylindrical portion that relatively slides on the outer peripheral surface of the fixed-side sleeve in the sliding sleeve One end portion is formed to extend axially.

[0007]

[0008] Moreover, according to the features of the present invention configured as described above ​Since the concave or convex cam portion formed on the sliding sleeve extends axially at one end of the sliding sleeve formed in a cylindrical shape, the sliding sleeve itself can be configured compactly without increasing the radial dimension of the sliding sleeve.

[0009] Another feature of the present invention is that, in the pulley device, the concave or convex cam portion formed on the sliding sleeve is non-contact with the fixed-side sleeve the main body of in the pulley device.

[0010] According to another feature of the present invention configured as described above, in the pulley device, since the concave or convex cam portion formed on the sliding sleeve is configured to be non-contact with the fixed-side sleeve the main body of the frictional resistance during the sliding of the sliding sleeve can be reduced and it can slide smoothly.

[0011] Another feature of the present invention is that, in the pulley device, the movable-side sleeve is formed with a cam connecting portion formed in a concave or convex shape, and the sliding sleeve is formed with a convex or concave sleeve connecting portion that fits into the cam connecting portion.

[0012] According to another feature of the present invention configured as described above, in the pulley device, since the sleeve connecting portion formed in a convex or concave shape on the sliding sleeve is connected by fitting into the cam connecting portion formed in a concave or convex shape on the movable-side sleeve, the sliding sleeve can be integrated with the movable-side sleeve with a simple configuration.

[0013] Another feature of the present invention is that, in the pulley device, the sliding sleeve and the fixed-side sleeve are made of different materials.

[0014] According to another feature of the present invention configured as described above, since the sliding sleeve and the fixed-side sleeve of the pulley device are made of different materials, it is possible to improve the slidability of both and suppress wear deterioration. In this case, the pulley device may be configured such that the sliding sleeve is made of a resin material and the fixed-side sleeve is made of a metal material.

[0019] Further, the present invention can be implemented not only as an invention of a pulley device but also as an invention of a centrifugal clutch provided with this pulley device.

[0020] Specifically, the centrifugal clutch may include the pulley device according to any one of claims 1 to 4, a drive plate that is connected to the fixed-side sleeve and rotates integrally with the fixed-side driven plate, a clutch outer that has a cylindrical surface provided concentrically with the drive plate outside the drive plate and is connected to the drive shaft, and a clutch shoe that extends along the circumferential direction of the drive plate and faces the cylindrical surface of the clutch outer, and one end side in the circumferential direction is rotatably attached to the drive plate and the other end side is displaced toward the cylindrical surface side of the clutch outer. According to this, the centrifugal clutch can be expected to have the same operational effects as the above pulley device.

[0023] In addition, the centrifugal clutch has a fixed-side driven plate that has a fixed-side plate projecting radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receives a driving force from a driving source via a belt, and is rotationally driven; a movable-side driven plate that has a movable-side plate projecting radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiches the belt together with the fixed-side plate, and is rotationally driven while approaching or separating from the fixed-side plate by receiving the driving force from the driving source via the belt; a sliding sleeve formed in a cylindrical shape and provided between the fixed-side sleeve and the movable-side sleeve, provided so as not to be relatively displaceable with respect to the fixed-side sleeve and relatively slidable with respect to the inner peripheral surface of the movable-side sleeve; a concave cam portion formed by helically notching along the axial direction in one of the sliding sleeve and the movable-side sleeve; and a convex cam portion slidably fitted into the concave cam portion in the other of the sliding sleeve and the movable-side sleeve. a pulley device, a drive plate connected to the fixed-side sleeve and integrally rotationally driven with the fixed-side driven plate, a clutch outer connected to the drive shaft having a cylindrical surface provided concentrically with the drive plate outside the drive plate, and a clutch shoe extending along the circumferential direction of the drive plate and facing the cylindrical surface of the clutch outer, wherein one end side in the circumferential direction is rotatably attached to the drive plate and the other end side is displaced toward the cylindrical surface side of the clutch outer , The sliding sleeve is preferably provided on the drive plate

[0024] According to the features of the present invention configured as described above, The centrifugal clutch is a concave cam portion or a convex cam portion that meshes with a convex cam portion or a concave cam portion formed in the movable-side sleeve is formed on the cylindrical sliding sleeve provided so as not to be relatively rotationally displaceable with respect to the fixed-side sleeve, and the movable-side sleeve directly slides and displaces on this sliding sleeve. Thereby, according to the present invention centrifugal clutch , a cam mechanism composed of a convex cam portion and a concave cam portion can be smoothly operated. Also, according to the present invention centrifugal clutch , by forming a concave cam portion or a convex cam portion on the sliding sleeve, the number of parts can be reduced, and the pulley device can be miniaturized, lightened, and the manufacturing burden can be reduced.

[0025] In addition, another feature of the present invention is the above-mentioned centrifugal clutchIn this case, the sliding sleeve has a cylindrical main body portion provided between the fixed-side sleeve and the movable-side sleeve, and the concave cam portion or the convex cam portion is formed on the outside of the main body portion of the sliding sleeve. According to another feature of the present invention configured as described above, centrifugal clutch since the concave cam portion or the convex cam portion is formed on the outside of the main body portion of the sliding sleeve, the convex cam portion or the concave cam portion formed on the movable-side sleeve that slides on the main body portion can be smoothly cam-fitted.

[0026] Also, another feature of the present invention is that in the above centrifugal clutch case, the sliding sleeve and the movable-side sleeve are made of different materials. According to another feature of the present invention configured as described above, centrifugal clutch since the sliding sleeve and the movable-side sleeve are made of different materials, it is possible to improve the slidability of both and suppress wear deterioration. In this case, centrifugal clutch it is preferable that the sliding sleeve is made of a resin material and the movable-side sleeve is made of a metal material.

[0027] Also, the centrifugal clutch a pulley device, includes a drive plate that is connected to the fixed-side sleeve and rotates integrally with the fixed-side driven plate, a clutch outer that has a cylindrical surface provided concentrically with the drive plate outside the drive plate and is connected to the drive shaft, and a clutch shoe that extends along the circumferential direction of the drive plate and faces the cylindrical surface of the clutch outer, and one end side in the circumferential direction is rotatably attached to the drive plate and the other end side is displaced toward the cylindrical surface side of the clutch outer. , the pulley device isA fixed-side driven plate that has a fixed-side plate projecting radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receives the driving force from a drive source via a belt, and is rotationally driven; and a movable-side driven plate that has a movable-side plate projecting radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiches the belt together with the fixed-side plate, and is rotationally driven while approaching or separating from the fixed-side plate by receiving the driving force from the drive source via the belt. formed in a cylindrical shape Provided between the fixed-side sleeve and the movable-side sleeve 、 A sliding sleeve that is formed in a cylindrical shape, is provided so as not to be relatively displaceable with respect to the fixed-side sleeve, and slidably moves relative to the movable-side sleeve; a concave cam portion formed by helically notching one of the sliding sleeve and the movable-side sleeve along the axial direction; and a convex cam portion that is slidably fitted into the concave cam portion in the other of the sliding sleeve and the movable-side sleeve. 、 The sliding sleeve may be provided on the drive plate. According to this, the centrifugal clutch can be expected to have the same operational effects as the pulley device described above. Moreover, according to the features of the present invention configured as described above Since the sliding sleeve is provided on the drive plate in the centrifugal clutch, the configuration of the fixed-side driven plate can be simplified and its weight can be reduced.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0029] <First Embodiment> Hereinafter, an embodiment of a pulley device and a centrifugal clutch equipped with the pulley device according to the present invention will be described with reference to the drawings. Fig. 1 is a schematic plan sectional view showing the configuration of a power transmission mechanism 100 equipped with a pulley device 130 and a centrifugal clutch 200 according to the first embodiment of the present invention. In this case, Fig. 1 shows the state where the upper half of each of the pulley device 130 and the centrifugal clutch 200 is in the state where the movable side driven plate 150 is closest to the fixed side driven plate 140, and the lower half of each shows the state where the movable side driven plate 150 is most separated from the fixed side driven plate 140.

[0030] The power transmission mechanism 100 equipped with these pulley devices 130 and centrifugal clutches 200 is mainly provided between the engine and the rear wheel, which is a driving wheel, in a two-wheeled vehicle such as a scooter, and is a mechanical device that transmits or cuts off the rotational driving force to the rear wheel while automatically changing the reduction ratio with respect to the engine speed. In this case, the centrifugal clutch 200 is a mechanical device that cuts off the transmission of the rotational driving force to the driven side until the engine reaches a predetermined speed, and transmits the rotational driving force to the driven side when the engine reaches a predetermined speed.

[0031] (Configuration of Pulley Device 130 and Centrifugal Clutch 200) This power transmission mechanism 100 mainly includes a transmission 101 and a centrifugal clutch 200 respectively. The transmission 101 is a mechanical device that steplessly decelerates the rotational driving force from an engine (not shown) and transmits it to the centrifugal clutch 200. It is mainly composed of a drive pulley 110, a V-belt 120, and a pulley device 130. Among these, the drive pulley 110 is a mechanical device provided on a crankshaft 111 extending from the engine and directly rotationally driven by the rotational driving force of the engine. It is mainly composed of a fixed drive plate 112 and a movable drive plate 113 respectively.

[0032] The fixed drive plate 112 is a component that rotationally drives while holding the V-belt 120 together with the movable drive plate 113. It is formed of a metal material into a conical cylinder shape. This fixed drive plate 112 is fixedly attached to the crankshaft 111 with the convex side facing the movable drive plate 113 side (engine side). That is, the fixed drive plate 112 always rotationally drives integrally with the crankshaft 111. Also, a plurality of heat dissipation fins 112a are provided radially on the concave side surface of the fixed drive plate 112 around the axis of the crankshaft 111.

[0033] The movable drive plate 113 is a component that rotationally drives while holding the V-belt 120 together with the fixed drive plate 112. It is formed of a metal material into a conical cylinder shape. This movable drive plate 113 is attached to the crankshaft 111 with the convex side facing the fixed drive plate 112. In this case, the movable drive plate 113 is attached via an impregnated bush on a sleeve bearing 114 that fits fixedly to the crankshaft 111, and is slidably attached to the sleeve bearing 114 in the axial direction and circumferential direction respectively.

[0034] On one side, a plurality of roller weights 115 are provided on the concave surface of the movable drive plate 113 in a state of being pressed by a lamp plate 116. The roller weight 115 is a component for pressing the movable drive plate 113 toward the fixed drive plate 112 in cooperation with the lamp plate 116 by being displaced radially outward as the rotation speed of the movable drive plate 113 increases, and is formed by shaping a metal material into a cylindrical shape. Further, the lamp plate 116 is a component for pressing the roller weight 115 toward the movable drive plate 113 side, and is formed by bending a metal plate toward the movable drive plate 113 side.

[0035] The V-belt 120 is a component for transmitting the rotational driving force of the drive pulley 110 to the driven pulley 131 of the pulley device 130, and is formed in an endless ring shape with a core wire covered with an elastic material such as a rubber material. This V-belt 120 is disposed between the fixed drive plate 112 and the movable drive plate 113 and between the fixed-side driven plate 140 and the movable-side driven plate 150 in the driven pulley 131, and is installed between the drive pulley 110 and and the driven pulley 131.

[0036] The pulley device 130 is a mechanical device that is rotationally driven by the rotational driving force from the engine transmitted through the drive pulley 110 and the V-belt 120, and is constituted by the driven pulley 131. As shown in FIG. 2, the driven pulley 131 is constituted by a fixed-side driven plate 140 and a movable-side driven plate 150.

[0037] The fixed-side driven plate 140 is a component that rotationally drives while holding the V-belt 120 together with the movable-side driven plate 150, and is formed by shaping a metal material such as an aluminum material into a conical cylindrical shape. This fixed-side driven plate 140 is mainly constituted by a fixed-side plate 141 and a fixed-side sleeve 142.

[0038] The fixed-side plate 141 is a portion that sandwiches the V-belt 120 together with the movable-side plate 151, and is formed in a conical surface shape that protrudes convexly toward the movable-side plate 151 side. A fixed-side sleeve 142 is formed at the center of this fixed-side plate 141.

[0039] The fixed-side sleeve 142 is a portion that rotates and is driven integrally with the fixed-side plate 141, and is formed in a cylindrical shape that extends in a direction orthogonal to the fixed-side plate 141. At one end (the right side in the drawing) of the fixed-side sleeve 142, the fixed-side plate 141 is connected, and a cam-forming protrusion 143 is formed in a portion adjacent to this connection portion. Also, at the other end (the left side in the drawing) of the fixed-side sleeve 142, an external-tooth-shaped spline is formed, and a drive plate 210 is connected by spline fitting through this spline.

[0040] The cam-forming protrusion 143 is a portion for forming a concave cam portion 144 in the fixed-side sleeve 142, and is formed to protrude convexly from the outer surface of the fixed-side sleeve 142. Here, the concave cam portion 144 is a portion where the convex cam portion 154 fits in a slidable state. In the present embodiment, the cam-forming protrusion 143 is formed in a spiral shape that extends in the axial direction while being twisted in the circumferential direction of the fixed-side sleeve 142. In this case, three cam-forming protrusions 143 are formed at equal intervals in the circumferential direction of the fixed-side sleeve 142.

[0041] As a result, on the outer peripheral portion of the fixed-side sleeve 142, one concave cam portion 144 is formed between two adjacent cam-forming protrusions 143. Therefore, on the outer peripheral portion of the fixed-side sleeve 142, three concave cam portions 144 are formed via the cam-forming protrusions 143 in the circumferential direction. In this case, the three concave cam portions 144 are each formed in a groove shape that extends in a spiral shape in the axial direction of the fixed-side sleeve 142. Further, the bottoms of the three concave cam portions 144 are formed to protrude from the outer surface of the fixed-side sleeve 142. That is, the fixed-side sleeve 142 is formed with a slightly thicker outer diameter at the portion where the cam-forming protrusions 143 are formed, thereby enhancing rigidity.

[0042] This fixed-side driven plate 140 is integrally formed by integrally molding the fixed-side sleeve 142 including the cam-forming protrusions 143 and the concave cam portions 144 and the fixed-side plate 141 with the same material. Note that the fixed-side driven plate 140 may be integrally formed by molding the fixed-side sleeve 142 including the cam-forming protrusions 143 and the concave cam portions 144 and the fixed-side plate 141 as separate parts and connecting them to each other via welding or the like. Further, the fixed-side driven plate 140 may be formed on the fixed-side sleeve 142 by configuring the cam-forming protrusions 143 separately from the fixed-side sleeve 142 and connecting them.

[0043] In this fixed-side driven plate 140, a drive shaft 145 penetrates through a fixed-side sleeve 142. The drive shaft 145 is a metal rotating shaft body for driving the rear wheel of a motorcycle on which this power transmission mechanism 100 is mounted via a transmission (not shown). In this case, the rear wheel of the motorcycle is attached to one end (not shown on the right side in the figure) of the drive shaft 145. The drive shaft 145 supports the fixed-side driven plate 140 via bearings 146a and 146b. Further, a male thread is formed on the tip end portion on the left side in the figure of the drive shaft 145, and a clutch outer 230 is attached via this male thread and a nut that is threadedly engaged with the male thread. In FIG. 1, the drive shaft 145 is shown by a two-dot chain line.

[0044] The bearings 146a and 146b are annular parts for supporting the fixed-side driven plate 140 in a state where it can be rotationally driven on the drive shaft 145. In this case, the bearing 146a is provided at the foremost end portion (the left end portion in the figure) where the drive shaft 145 supports the fixed-side sleeve 142. Further, the bearing 146b is provided at the rearmost end portion (the right end portion in the figure) where the drive shaft 145 supports the fixed-side sleeve 142. That is, the bearing 146b is provided at a position that overlaps with the inside in the radial direction of the cam forming protrusion 143 and the concave cam portion 144. The bearing 146b may be configured with the same load-bearing capacity as the bearing 146a, but in this embodiment, it is formed with a longer axial length than the bearing 146a and is configured with a larger load-bearing capacity.

[0045] The movable-side driven plate 150 is a component that rotates and drives while holding the V-belt 120 together with the fixed-side driven plate 140, and is configured by forming a metal material such as an aluminum material into a conical cylinder shape. The movable-side driven plate 150 is mainly composed of a movable-side plate 151 and a movable-side sleeve 152.

[0046] The movable side plate 151 is a part that sandwiches the V-belt 120 together with the fixed side plate 141, and is formed in a conical surface shape that protrudes convexly toward the fixed side plate 141 side. A movable side sleeve 152 is formed at the center of this movable side plate 151.

[0047] The movable side sleeve 152 is a part that rotates and drives integrally with the movable side plate 151, and is formed in a cylindrical shape extending in a direction orthogonal to the movable side plate 151. In this case, the movable side sleeve 152 is formed with an inner diameter through which the fixed side sleeve 142 can pass. One end (right side in the drawing) of the movable side sleeve 152 is connected to the movable side plate 151, and a cam connection part 152a is formed at the other end (left side in the drawing).

[0048] The cam connection part 152a is a part for connecting the sliding sleeve 153, and is formed by notching a part of the end of the movable side sleeve 152 in a concave shape in the axial direction. In the present embodiment, the cam connection part 152a is formed with three concave notches at equal intervals along the circumferential direction at the end of the movable side sleeve 152.

[0049] As shown in FIG. 2, the sliding sleeve 153 is arranged between the fixed side sleeve 142 and the movable side sleeve 152 to slide the movable side sleeve 152 relative to the fixed side sleeve 142 and form a convex cam part 154 that meshes with the concave cam part 144. It is a component formed by shaping a resin material into a cylindrical shape. The cylindrical body constituting this sliding sleeve 153 is formed with an outer diameter that slidably fits onto the inner peripheral surface 152b movable side sleeve 152 and an inner diameter that slidably fits onto the outer peripheral surface of the fixed side sleeve 142. Further, the sliding sleeve 153 has a sleeve connection part 153a formed at one end of the cylindrical body and a convex cam part 154 formed at the other end.

[0050] The sleeve connecting portion 153a is a portion that fits into the cam connecting portion 152a, and is formed to project radially outward from one end of the sliding sleeve 153. In this case, the sleeve connecting portion 153a is formed with three protruding portions along the circumferential direction at the end of the sliding sleeve 153 so as to fit into the three cam connecting portions 152a respectively in an evenly arranged manner.

[0051] The convex cam portion 154 is a portion that protrudes from the movable-side sleeve 152 and slidably fits into the concave cam portion 144 formed on the fixed-side sleeve 142, and is formed to project helically in the axial direction at the end of the sliding sleeve 153. In this case, the convex cam portion 154 may be configured to contact the outer peripheral surface of the fixed-side sleeve 142, but in this embodiment, it is formed to extend in a non-contact state. The convex cam portion 154 is formed in three at the end of the sliding sleeve 153 at equal intervals in the circumferential direction so as to correspond to the concave cam portion 144. inner peripheral surface 152b That is, between each of the three convex cam portions 154, a cam formation notch portion 153b for forming each convex cam portion 154 extends helically and is formed respectively. And these three cam formation notch portions 153b are slidably fitted with a cam formation protrusion portion 143 formed on the fixed-side sleeve 142. Therefore, the cam formation protrusion portion 143 formed on the fixed-side sleeve 142 can be regarded as a convex cam portion according to the present invention formed on the fixed-side sleeve 142, and the cam formation notch portion 153b formed on the sliding sleeve 153 (movable-side sleeve 152) can also be regarded as a concave cam portion according to the present invention formed on the sliding sleeve 153 (movable-side sleeve 152).

[0052]

[0053] ​This sliding sleeve 153 is fixedly fitted into the movable-side sleeve 152 of the movable-side driven plate 150 through an adhesive or the like in a state where the sleeve connecting portion 153a is fitted into the cam connecting portion 152a. Thereby, the sliding sleeve 153 rotates integrally with the movable-side sleeve 152 in a state where the convex cam portion 154 is fitted into the concave cam portion 144 formed in the fixed-side sleeve 142.

[0054] Note that, as the resin material constituting the sliding sleeve 153, a thermoplastic resin or a thermosetting resin having heat resistance and wear resistance can be used, and engineering plastics or super engineering plastics are preferable. Specifically, as the thermoplastic resin, a polyetheretherketone resin (PEEK), a polyphenylene sulfide resin (PPS), a polyamideimide resin (PAI), a fluororesin (PTFE), or a polyimide resin (PI) can be used, and as the thermosetting resin, a diallyl phthalate resin (PDAP), an epoxy resin (EP), or a silicone resin (SI) can be used.

[0055] On the other hand, a torque spring 155 is provided between the concave surface of the movable-side driven plate 150 and the drive plate 210 in the centrifugal clutch 200. The torque spring 155 is a coil spring for elastically pressing the movable-side driven plate 150 toward the fixed-side driven plate 140. That is, this transmission 101 steplessly changes the engine speed according to the magnitude relationship between the diameter that sandwiches the V-belt 120 defined by the distance between the fixed drive plate 112 and the movable drive plate 113 and the diameter that sandwiches the V-belt 120 defined by the distance between the fixed-side driven plate 140 and the movable-side driven plate 150. And a centrifugal clutch 200 is provided on each tip end side of the fixed-side sleeve 142 and the drive shaft 145.

[0056] The centrifugal clutch 200 is a mechanical device that transmits or shuts off the rotational driving force of the engine transmitted via the transmission 101 to the drive shaft 145, and mainly includes a drive plate 210, three clutch weights 220, and a clutch outer 230.

[0057] The drive plate 210 is a component that rotates integrally with the fixed-side sleeve 142, and is formed of a stepped disk-shaped metal material. More specifically, the drive plate 210 is formed with an internal tooth-shaped spline into which the external tooth-shaped spline of the fixed-side sleeve 142 penetrates and fits at the center of the flat bottom portion 211, and a flange portion 212 that projects radially outward in a flange shape through a stepped portion standing up around the bottom portion 211.

[0058] Also, the torque spring 155 is provided inside the stepped portion at the outer edge portion of the bottom portion 211 of the drive plate 210. Further, on the flange portion 212, three swing support pins 213 and weight pressing body support portions 215 are provided at equal intervals along the circumferential direction.

[0059] The swing support pin 213 is a component for rotatably supporting one end side of the clutch weight 220 described later and swinging the other end side, and is formed of a stepped bar made of metal. In this case, the swing support pin 213 is fixedly attached to the flange portion 212 by a mounting bolt 213a. The swing support pin 213 supports the clutch weight 220 in a state of sandwiching it with a side plate 214 attached to the tip of the swing support pin 213 while passing through the pin sliding hole 222 of the clutch weight 220.

[0060] The side plate 214 is a component for preventing the three clutch weights 220 from coming off each swing support pin 213, and is formed of a metal material in a ring shape. This side plate 214 is arranged facing each clutch weight 220 on the side opposite to the drive plate 210 with respect to the three clutch weights 220.

[0061] The weight pressing body support portion 215 is a component for rotatably supporting the weight pressing body 216, and is composed of a stepped rod made of metal. This weight pressing body support portion 215 is formed to project in a pin shape on the flange portion 212 facing a portion on the tip end side of the clutch weight 220 rather than the pin sliding hole 222 in the clutch weight 220. The weight pressing body 216 is a component for pressing the clutch weight 220 toward the clutch outer 230, and is formed of a resin material in a cylindrical shape.

[0062] The three clutch weights 220 are components for transmitting or blocking the rotational driving force from the engine to the drive shaft 145 by contacting or separating from the clutch outer 230 via the clutch shoe 221 according to the rotational speed of the drive plate 210, and are formed of a metal material (for example, zinc material) in a curved shape extending along the circumferential direction of the drive plate 210.

[0063] The clutch shoe 221 is a component for increasing the frictional force against the inner peripheral surface of the clutch outer 230, and is formed of a friction material in a plate shape extending in an arc shape. This clutch shoe 221 is provided in a state of being attached to the outer peripheral surface on the tip end side of the clutch weight 220, which is the other end side in each clutch weight 220.

[0064] These clutch weights 220 each have a pin sliding hole 222 formed as a long hole-shaped through hole on one end side, and are rotatably supported by a swing support pin 213 through this pin sliding hole 222. Further, each clutch weight 220 has its other end side connected to an adjacent clutch weight 220 by a connecting spring 223 and is pulled inward toward the drive plate 210. That is, the clutch weight 220 is supported on the drive plate 210 through a swing support pin 213 and a pin sliding hole 222 such that the other end side provided with the clutch shoe 221 swings with respect to the clutch outer 230.

[0065] The connecting spring 223 is a component for applying a tensile force to the clutch weight 220 and pulling the other end side in a direction away from the clutch outer 230, and is composed of a metal coil spring. This connecting spring 223 is respectively installed between clutch weights 220 adjacent to each other along the circumferential direction of the drive plate 210.

[0066] Also, on the inner surface of each clutch weight 220 facing the drive plate 210, a pressing body accommodating portion 224 is respectively formed. The pressing body accommodating portion 224 is a portion where a pressing body receiving portion 224a for accommodating the weight pressing body 216 and against which the weight pressing body 216 is pressed is formed, and is formed by being notched in a concave shape on the inner surface of the clutch weight 220.

[0067] The pressing body receiving portion 224a is a portion for displacing the clutch weight 220 toward the clutch outer 230 side when the weight pressing body 216 is pressed. This pressing body receiving portion 224a is composed of a smooth curved surface where the side surface in the pressing body accommodating portion 224 curves and extends rearward and outward in the rotational driving direction of the drive plate 210.

[0068] The clutch outer 230 is a component that rotates integrally with the drive shaft 145, and is formed of a metal material into a cup shape covering the outer peripheral surface of the clutch weight 220 from the drive plate 210. That is, the clutch outer 230 is configured to have a cylindrical surface 231 that makes frictional contact with the clutch shoe 221 of the clutch weight 220 displaced to the outer peripheral side of the drive plate 210.

[0069] (Operation of the pulley device 130 and the centrifugal clutch 200) Next, the operation of the pulley device 130 and the centrifugal clutch 200 configured as described above will be described. This centrifugal clutch 200 functions as a part of the power transmission mechanism 100 disposed between the engine and the rear wheel serving as the drive wheel in a two-wheeled vehicle (for example, a scooter). First, when the engine is in the idling state, as shown in FIG. 1, the centrifugal clutch 200 shuts off the transmission of the driving force between the engine and the drive shaft 145.

[0070] Specifically, in the pulley device 130, the driven pulley 131 is rotationally driven by the rotational driving force of the engine transmitted through the drive pulley 110 and the V-belt 120, respectively. Here, the driven pulley 131 is connected to the fixed-side driven plate 140 via the sliding sleeve 153, and the fixed-side driven plate 140 is directly connected to the drive plate 210. Thereby, the drive plate 210 is rotationally driven at the same rotational speed as the fixed-side driven plate 140 and the movable-side driven plate 150. That is, the three clutch weights 220 provided on the drive plate 210 in the centrifugal clutch 200 are rotationally driven at the same rotational speed as the drive plate 210.

[0071] However, in this case, since the centrifugal force acting on the clutch weight 220 of the centrifugal clutch 200 is smaller than the elastic force (tensile force) of the connecting spring 223, the clutch weight 220 does not tilt toward the cylindrical surface 231 of the clutch outer 230 until the clutch shoe 221 comes into contact with the cylindrical surface 231 of the clutch outer 230. Therefore, the centrifugal clutch 200 is in a clutch-off state where the rotational driving force of the engine is not transmitted to the drive shaft 145.

[0072] In this clutch-off state, the driven pulley 131 is elastically pressed by the torque spring 155 such that the movable-side driven plate 150 is at the closest position to the fixed-side driven plate 140 or in the vicinity thereof. For this reason, the movable-side driven plate 150 transmits the rotational driving force to the fixed-side driven plate 140 in a state where the convex cam portion 154 in the sliding sleeve 153 is fitted deep into the concave cam portion 144 formed in the fixed-side sleeve 142 of the fixed-side driven plate 140. That is, since the movable-side driven plate 150 transmits the rotational driving force with the contact area between the convex cam portion 154 and the concave cam portion 144 being the maximum or almost the maximum, it can stably transmit the rotational driving force to the fixed-side driven plate 140 at low rotational speeds when the rotational speed, such as during engine idling, tends to be unstable.

[0073] Next, the centrifugal clutch 200 transmits the rotational driving force of the engine to the drive shaft 145 in response to an increase in the rotational speed of the engine due to the accelerator operation by the driver in the motorcycle. Specifically, as the rotational speed of the engine increases, the centrifugal force acting on the clutch weight 220 of the centrifugal clutch 200 becomes larger than the elastic force (tensile force) of the connecting spring 223, and the clutch weight 220 rotates and displaces radially outward about the swing support pin 213.

[0074] That is, as the engine speed increases, the clutch weight 220 rotates and displaces toward the cylindrical surface 231 side of the clutch outer 230 while resisting the elastic force (tensile force) of the connecting spring 223. As a result, the clutch shoe 221 contacts the cylindrical surface 231.

[0075] As a result, the clutch weight 220 receives a reaction force in the direction opposite to the rotational driving direction via the clutch shoe 221 and relatively displaces in the direction opposite to the rotational driving direction of the drive plate 210. In this case, as the pressing body receiving portion 224a rides on the weight pressing body 216 while rotating and displacing the weight pressing body 216, the clutch weight 220 is pushed toward the clutch outer 230 on the outer side in the radial direction, and the clutch shoe 221 is strongly pressed against the cylindrical surface 231.

[0076] That is, after the clutch shoe 221 contacts the cylindrical surface 231 of the clutch outer 230, the clutch shoe 221 is pressed against the cylindrical surface 231 in an extremely short time (in other words, instantaneously), and the clutch weight 220 enters a wedged state between the weight pressing body 216 and the clutch outer 230. As a result, the centrifugal clutch 200 enters a clutch-on state in which the rotational driving force of the engine is completely transmitted to the drive shaft 145. Therefore, the motorcycle can travel with the rear wheel rotationally driven by the rotational driving force of the engine.

[0077] In the process of shifting to this clutch-on state, as the engine speed increases, the movable side driven plate 150 of the driven pulley 131 displaces toward the side away from the fixed side driven plate 140 against the elastic force of the torque spring 155. In this case, the movable side driven plate 150 is separated from the fixed side driven plate 140 as the sliding sleeve 153 assembled to the movable side sleeve 152 slides on the fixed side sleeve 142 to the left side in the drawing.

[0078] Therefore, the convex cam portion 154 formed on the sliding sleeve 153 slides and displaces to the left side in the drawing with respect to the concave cam portion 144 formed on the fixed-side driven plate 140. As a result, the cam forming protrusion 143 and the concave cam portion 144 formed on the fixed-side driven plate 140 are exposed to the V-belt 120 side as the amount of fitting with the cam forming notch portion 153b and the convex cam portion 154 decreases. That is, the movable-side driven plate 150 transmits the rotational driving force to the fixed-side driven plate 140 with the contact area between the convex cam portion 154 and the concave cam portion 144 being the minimum or nearly the minimum contact area.

[0079] On the other hand, when the engine speed decreases, the centrifugal clutch 200 shuts off the transmission of the engine's rotational driving force to the drive shaft 145. Specifically, as the engine speed decreases, the centrifugal force acting on the clutch weight 220 becomes smaller than the elastic force (tensile force) of the connecting spring 223, and the clutch weight 220 rotates and displaces radially inward about the swing support pin 213.

[0080] As a result, the clutch weight 220 returns to its original position (the position at idling) with the clutch shoe 221 separated from the cylindrical surface 231 of the clutch outer 230. That is, the centrifugal clutch 200 is in a clutch-off state where the clutch shoe 221 does not contact the clutch outer 230 and does not transmit the rotational driving force.

[0081] In this case, as the engine speed decreases, the driven pulley 131 displaces in such a way that the movable-side driven plate 150 approaches the fixed-side driven plate 140 by the elastic force of the torque spring 155. In this case, the movable-side driven plate 150 approaches the fixed-side driven plate 140 as the sliding sleeve 153 assembled to the movable-side sleeve 152 slides on the fixed-side sleeve 142 to the right side in the drawing. Thereby, in the concave cam portion 144 formed in the fixed-side driven plate 140, the fitting amount with the convex cam portion 154 formed in the movable-side driven plate 150 increases and the exposed amount decreases as the convex cam portion 154 slides and displaces to the right side in the drawing.

[0082] As can be understood from the above operation description, according to the first embodiment, the pulley device 130 is formed with a convex cam portion 154 that meshes with a concave cam portion 144 formed in the fixed-side sleeve 142 on a cylindrical sliding sleeve 153 that is displaced integrally with the movable-side sleeve 152 with respect to the fixed-side sleeve 142, and this sliding sleeve 153 directly slides and displaces with respect to the fixed-side sleeve 142. Thereby, according to the pulley device 130 according to the present invention, the sliding sleeve 153 can be displaced smoothly as compared with the case where the sliding sleeve 153 is displaced via the movable-side sleeve 152. Further, according to the pulley device 130 according to the present invention, by forming the convex cam portion 154 on the sliding sleeve 153, the number of parts can be reduced, and the pulley device 130 and the centrifugal clutch 200 can be miniaturized, lightened, and the manufacturing burden can be reduced.

[0083] Furthermore, in practicing the present invention, it is not limited to the first embodiment, and various modifications are possible without departing from the object of the present invention.

[0084] For example, in the first embodiment, the pulley device 130 forms the concave cam portion 144 in the fixed-side sleeve 142 of the fixed-side driven plate 140, and sliding sleeve 153A convex cam portion 154 that protrudes radially inward is formed. However, the pulley device 130 can also be configured by forming a convex cam portion 154 that protrudes radially outward on the fixed-side sleeve 142 of the fixed-side driven plate 140 and forming a concave cam portion 144 on the sliding sleeve 153. In this case, the pulley device 130 forms a groove-shaped or through-hole-shaped cam formation notch portion 153b on the fixed-side sleeve 142 of the fixed-side driven plate 140 and forms a cam formation protrusion portion 143 on the sliding sleeve 153.

[0085] That is, the concave cam portion 144 can be formed by being spirally extended and notched into a through-hole shape or a groove shape in one of the fixed-side sleeve 142 and the sliding sleeve 153. Also, in this case, the convex cam portion 154 can be formed to protrude radially in the other of the fixed-side sleeve 142 and the sliding sleeve 153 so as to be slidably fitted into the concave cam portion 144.

[0086] Also, in the first embodiment, the concave cam portion 144 is formed in a bottomed groove shape. However, the concave cam portion 144 can also be formed by a through-hole that penetrates the fixed-side sleeve 142 being spirally extended in the axial direction of the fixed-side sleeve 142. According to this, since the pulley device 130 has a through-hole-shaped concave cam portion 144 formed in the fixed-side sleeve 142, it is possible to ensure air permeability inside the fixed-side sleeve 142, improve heat dissipation, and improve durability. Note that the concave cam portion 144 can also be formed in a through-hole shape when formed on the sliding sleeve 153.

[0087] Also, in the first embodiment, the concave cam portion 144 is formed by the cam formation protrusion portion 143 formed on the outer peripheral surface of the fixed-side sleeve 142. Thereby, the concave cam portion 144 can function as a rib that thickens the wall thickness of the fixed-side sleeve 142, improving rigidity and durability. However, the concave cam portion 144 can also be formed in a groove shape or a through-hole shape that is recessed concave from the surface of the outer peripheral surface of the fixed-side sleeve 142.

[0088] Further, in the above-described first embodiment, the convex cam portion 154 is formed to project axially in a spiral shape at the end of the sliding sleeve 153. As a result, the convex cam portion 154 projects from the inner peripheral surface 152b in a rail shape. However, the convex cam portion 154 may be configured to project convexly from the movable-side sleeve 152 and fit slidably into the concave cam portion 144. Therefore, the convex cam portion 154 can be formed, for example, in a pin shape configured in a rod state. inner peripheral surface 152b from the movable-side sleeve 152 and fit slidably into the concave cam portion 144. Therefore, the convex cam portion 154 can be formed, for example, in a pin shape configured in a rod state.

[0089] Further, in the above-described first embodiment, the sliding sleeve 153 is made of a resin material and the fixed-side sleeve 142 is made of a metal material. That is, the pulley device 130 is configured with the sliding sleeve 153 and the fixed-side sleeve 142 made of different materials. As a result, the pulley device 130 can improve the slidability between the sliding sleeve 153 and the fixed-side sleeve 142 and suppress wear deterioration between the concave cam portion 144 and the convex cam portion 154. However, the pulley device 130 can also be configured with the sliding sleeve 153 and the fixed-side sleeve 142 made of the same material. Also, the pulley device 130 can be configured with the sliding sleeve 153 and the fixed-side sleeve 142 made of materials other than resin materials and metal materials, for example, ceramic materials.

[0090] <Second Embodiment> Next, a second embodiment of the pulley device according to the present invention and a centrifugal clutch equipped with the pulley device will be described with reference to FIGS. 3 to 6 respectively. In the first embodiment, the sliding sleeve 153 in the pulley device 130 is formed in a cylindrical shape provided between the fixed-side sleeve 142 and the movable-side sleeve 152, and is configured to be displaced integrally with the movable-side sleeve 152 and slide relative to the fixed-side sleeve 142. On the other hand, the sliding sleeve 160 in the pulley device 130 in the second embodiment is formed in a cylindrical shape provided between the fixed-side sleeve 142 and the movable-side sleeve 152, and is provided so as not to be relatively displaceable with respect to the fixed-side sleeve 142 and slide relative to the movable-side sleeve 152, which is different from the first embodiment.

[0091] Therefore, in the pulley device 130 and the centrifugal clutch 200 in this second embodiment, the description will be centered on the parts different from the pulley device 130 and the centrifugal clutch 200 in the first embodiment, and the description of the common parts and corresponding parts in both embodiments will be omitted as appropriate. In FIG. 3, the illustration of the configuration on the drive pulley 110 side in the transmission 101 is omitted. Also, in FIG. 3, similar to FIG. 1 in the first embodiment, the upper half views of the pulley device 130 and the centrifugal clutch 200 show the state where the movable-side driven plate 150 is closest to the fixed-side driven plate 140, and the lower half views show the state where the movable-side driven plate 150 is most separated from the fixed-side driven plate 140.

[0092] (Configuration of Pulley Device 130 and Centrifugal Clutch 200) The pulley device 130 is composed of a driven pulley 131 having a fixed-side driven plate 140 and a movable-side driven plate 150, similar to the pulley device 130 in the first embodiment.

[0093] The fixed-side driven plate 140 is configured to include a fixed-side plate 141 and a fixed-side sleeve 142 similar to those of the fixed-side plate 141 and the fixed-side sleeve 142 in the first embodiment. In this case, the fixed-side sleeve 142 is different from the first embodiment in that the cam formation protrusion 143 and the concave cam portion 144 in the first embodiment are not formed.

[0094] As shown in FIG. 4, the movable-side driven plate 150 is configured to include a movable-side plate 151 and a movable-side sleeve 152 similar to those of the movable-side plate 151 and the movable-side sleeve 152 in the first embodiment. In this case, a concave cam portion 156 is formed at the end of the movable-side sleeve 152 on the drive plate 210 side instead of the cam connection portion 152a in the first embodiment.

[0095] The concave cam portion 156 is a portion where the convex cam portion 165 formed on the sliding sleeve 160 to be described later fits in a slidable state, and is formed in a helical shape extending in the axial direction while being twisted in the circumferential direction at the left end portion in the drawing of the movable-side sleeve 152. In this case, the concave cam portion 156 is formed by being notched in a state of penetrating in the radial direction. Further, three concave cam portions 156 are formed at equal intervals in the circumferential direction of the movable-side sleeve 152.

[0096] That is, the concave cam portion 156 is movable-side sleeve 152 formed between each of the three remaining concave cam formation portions 157 at the end of the. Each of these concave cam portions 156 is formed to be thinner than the annular gap S of the outer cylindrical portion 162 formed on the sliding sleeve 160, and is formed so as not to contact the inner and outer side walls in the radial direction inside the outer cylindrical portion. Note that the concave cam portion 156 may be formed in a bottomed groove shape on the outer peripheral portion of the movable-side sleeve 152 instead of in a through-hole shape. Further, at least one concave cam portion 156 may be formed with respect to the sliding sleeve 160. Also, the concave cam portion 156 may be formed so as to contact the inner and outer side walls in the radial direction inside the outer cylindrical portion.

[0097] As shown in FIGS. 5 and 6 respectively, the sliding sleeve 160 is disposed between the fixed-side sleeve 142 and the movable-side sleeve 152 to slide the movable-side sleeve 152 relative to the fixed-side sleeve 142 and form a convex cam portion that meshes with the concave cam portion 156. It is a component formed by molding a resin material into a cylindrical shape. In this case, the sliding sleeve 160 can be composed of the same resin material as the sliding sleeve 153 in the above embodiment. This sliding sleeve 160 is mainly composed of a main body portion 161 and an outer cylindrical portion 162.

[0098] The main body portion 161 is a portion that fits onto the outer peripheral portion of the fixed-side sleeve 142 of the fixed-side driven plate 140 in a state where relative displacement is impossible and fits onto the movable-side sleeve 152 of the movable-side driven plate 150 in a slidable state, and is formed in a cylindrical shape. The outer cylindrical portion 162 is a portion where the convex cam portion 165 is formed, and is formed in a cylindrical shape that covers the end portion of the main body portion 161 on the drive plate 210 side with a gap S therebetween.

[0099] In this case, the ring-shaped gap S formed inside the outer cylindrical portion 162 is a portion where the convex cam portion 165 is formed and the concave cam portion 156 and the concave cam forming portion 157 are respectively inserted. Also, on the outer peripheral portion of the outer cylindrical portion 162, a spring receiving portion 163 and a plate fitting portion 164 are respectively formed at the end portion on the drive plate 210 side. And the portion of the outer cylindrical portion 162 on the movable-side plate 151 side rather than the spring receiving portion 163 covers the outside of the concave cam forming portion 157 to prevent contact with the torque spring 155.

[0100] The spring receiving portion 163 is a portion that receives the end portion on the drive plate 210 side of the torque spring 155, and is formed to project radially outward in a flange shape from the outer peripheral portion of the outer cylindrical portion 162. The plate fitting portion 164 is a portion for fitting into a sleeve fitting hole 217 formed in the drive plate 210 to rotationally drive the sliding sleeve 160 integrally with the drive plate 210, and is formed in a state of protruding from the end portion of the main body portion 161 and the end face of the spring receiving portion 163, respectively.

[0101] In the present embodiment, three plate fitting portions 164 are formed at equal intervals along the circumferential direction of the spring receiving portion 163. That is, the sliding sleeve 160 is rotationally driven integrally with the drive plate 210 and the fixed-side driven plate 140 when the plate fitting portion 164 fits into the sleeve fitting hole 217 formed in the drive plate 210. Further, a through hole through which the concave cam forming portion 157 formed in the movable-side sleeve 152 can penetrate is formed in the plate fitting portion 164.

[0102] The convex cam portion 165 is a portion where the concave cam portion 156 formed in the movable-side sleeve 152 slidably engages and fits, and is formed in a state of protruding into the space between the main body portion 161 and the outer cylindrical portion 162 in the sliding sleeve 160. In this case, the convex cam portion 165 is in the axial direction formed to extend in a spiral shape. Further, three convex cam portions 165 are formed at equal intervals in the circumferential direction of the sliding sleeve 160.

[0103] That is, between each of the three convex cam portions 165, cam formation notches 166 for forming each convex cam portion 165 extend in a spiral shape and are respectively formed. And these three cam formation notches 166 are slidably fitted with a concave cam formation portion 157 formed in the movable-side sleeve 152. Therefore, the concave cam formation portion 157 formed in the movable-side sleeve 152 can be regarded as the convex cam portion according to the present invention formed in the sliding sleeve 160, and the cam formation notch 166 formed in the sliding sleeve 160 can also be regarded as the concave cam portion according to the present invention formed in the sliding sleeve 160. Further, these cam formation notches 166 may be configured to contact the outer peripheral portion of the main body portion 161 of the sliding sleeve 160 and the inner peripheral portion of the outer cylindrical portion 162, but in the present embodiment, they are configured to be non-contact with the outer peripheral portion of the main body portion 161 and the inner peripheral portion of the outer cylindrical portion 162 respectively.

[0104] On the drive plate 210, a sleeve fitting hole 217 is formed outside an internal-tooth-shaped spline into which the fixed-side sleeve 142 in the bottom portion 211 is fitted. The sleeve fitting hole 217 is a through hole into which the three plate fitting portions 164 of the sliding sleeve 160 are respectively fitted, and three of them are formed at equal intervals along the circumferential direction of the drive plate 210.

[0105] (Operation of the pulley device 130 and the centrifugal clutch 200) Next, the operation of the pulley device 130 and the centrifugal clutch 200 configured as described above will be described.

[0106] First, when the centrifugal clutch 200 is in the clutch-off state, the driven pulley 131 is elastically pressed by the torque spring 155 at a position closest to or near the fixed-side driven plate 140 by the movable-side driven plate 150. In this case, the movable-side driven plate 150 is elastically pressed toward the fixed-side driven plate 140 as the movable-side sleeve 152 slides on the main body 161 of the sliding sleeve 160. Therefore, the movable-side driven plate 150 transmits the rotational driving force to the drive plate 210 in a state where the convex cam portion 165 formed on the sliding sleeve 160 fits into the concave cam portion 156 with the minimum or near-minimum contact area.

[0107] Next, when the centrifugal clutch 200 shifts to the clutch-on state, the driven pulley 131 is displaced toward the side away from the fixed-side driven plate 140 against the elastic force of the torque spring 155 as the rotational speed of the engine increases. In this case, the movable-side driven plate 150 is separated from the fixed-side driven plate 140 as the movable-side sleeve 152 slides leftward (as shown in the figure) on the sliding sleeve 160.

[0108] Accordingly, the concave cam portion 156 and the concave cam forming portion 157 formed on the movable-side sleeve 152 will penetrate deeply into the sliding sleeve 160. As a result, the movable-side driven plate 150 transmits the rotational driving force to the drive plate 210 in a state where the contact area between the convex cam portion 165 and the concave cam portion 156 is the maximum or near-maximum contact area.

[0109] On the other hand, when the engine speed decreases, the driven pulley 131 is displaced such that the movable side driven plate 150 approaches the fixed side driven plate 140 by the elastic force of the torque spring 155 as the engine speed decreases. In this case, the movable side driven plate 150 approaches the fixed side driven plate 140 as the movable side sleeve 152 slides on the sliding sleeve 160 to the right side in the drawing. As a result, the convex cam portion 165 formed on the sliding sleeve 160 transmits the rotational driving force of the movable side driven plate 150 to the drive plate 210 in a state where the fitting amount with the concave cam portion 156 formed on the movable side driven plate 150 is reduced as the concave cam portion 156 formed on the movable side driven plate 150 slides and displaces to the right side in the drawing.

[0110] As can be understood from the above operation description, according to the second embodiment, in the pulley device 130, the convex cam portion 165 that meshes with the concave cam portion 156 formed on the movable side sleeve 152 is formed on the cylindrical sliding sleeve 160 provided so as not to be relatively rotationally displaceable with respect to the fixed side sleeve 142, and the movable side sleeve 152 directly slides and displaces on this sliding sleeve 160. Thereby, according to the pulley device 130 according to the present invention, the cam mechanism including the convex cam portion 165 and the concave cam portion 156 can be smoothly operated. Further, according to the pulley device 130 according to the present invention, by forming the convex cam portion 165 on the sliding sleeve 160, the number of parts can be reduced, and the pulley device 130 can be downsized, lightened, and the manufacturing burden can be reduced.

[0111] Furthermore, in practicing the present invention, it is not limited to the second embodiment, and various modifications are possible without departing from the object of the present invention.

[0112] For example, in the above-described second embodiment, the pulley device 130 is configured by forming a concave cam portion 156 on the movable-side sleeve 152 and a convex cam portion 165 on the sliding sleeve 160. However, the pulley device 130 can also be configured by forming a convex cam portion 165 on the movable-side sleeve 152 and a concave cam portion 156 on the sliding sleeve 160. In this case, a convex cam portion 165 having the same shape as the concave cam forming portion 157 can be formed on the movable-side sleeve 152, and a cam forming notch portion 166 having the same shape as the concave cam portion 156 can be formed between these convex cam portions 165. Further, a concave cam portion 156 having the same shape as the cam forming notch portion 166 can be formed on the sliding sleeve 160, and a concave cam forming portion 157 having the same shape as the convex cam portion 165 can be formed between these concave cam portions 156.

[0113] That is, the concave cam portion 156 can be formed to extend spirally and be notched in a through-hole shape or a groove shape on one of the movable-side sleeve 152 and sliding sleeve 160 . Further, in this case, the convex cam portion 165 can be formed to project radially on the other of the movable-side sleeve 152 and sliding sleeve 160 so as to be slidably fitted into the concave cam portion 156.

[0114] Also, in the above-described second embodiment, the concave cam portion 156 is formed by notching so as to penetrate the movable-side sleeve 152. However, the concave cam portion 156 can also be formed in a groove shape that does not penetrate the outer peripheral surface of the movable-side sleeve 152 with a bottom or the inner peripheral surface of the movable-side sleeve 152 with a top. In this case, the convex cam portion 165 can be formed with a protruding amount that does not reach the main body portion 161 from the inner peripheral surface of the outer cylindrical portion 162 of the sliding sleeve 160 or with a protruding amount that does not reach the inner peripheral surface of the outer cylindrical portion 162 on the outer peripheral surface of the main body portion 161.

[0115] Further, the concave cam portion 156 can also be formed at a position protruding from the outer peripheral surface of the movable sleeve 152 like the concave cam portion 144 in the first embodiment. That is, the concave cam portion 156 can be formed between at least two cam forming protrusions 143 on the outer peripheral surface of the movable sleeve 152 by forming at least two cam forming protrusions 143 similar to the cam forming protrusions 143 in the first embodiment, thereby forming a concave cam portion 156 similar to the concave cam portion 144.

[0116] Also, in the second embodiment, the convex cam portion 165 is formed in a spiral shape in a state of being installed between the main body portion 161 and the outer cylindrical portion 162 of the sliding sleeve 160. However, the convex cam portion 165 concave cam portion 156 only needs to be configured to be slidably fitted therein. Therefore, the convex cam portion 165 can also be formed in a pin shape configured in a rod state, for example.

[0117] Also, in the second embodiment, the sliding sleeve 160 is configured to include an outer cylindrical portion 162 outside the main body portion 161. Thereby, the sliding sleeve 160 can prevent foreign matters from entering the cam fitting portion where the concave cam portion 156 and the convex cam portion 165 are cam-fitted, and can prevent the torque spring 155 from contacting the concave cam portion 156 and the convex cam portion 165, thereby maintaining smooth cam fitting over a long period. However, the sliding sleeve 160 can also be configured by omitting the outer cylindrical portion 162.

[0118] Also, in the second embodiment, the sliding sleeve 160 is connected to the sleeve fitting hole 217 of the drive plate 210. However, the sliding sleeve 160 only needs to be configured to rotate integrally with the fixed-side driven plate 140 and the drive plate 210. Therefore, the sliding sleeve 160 may be attached to the fixed-side sleeve 142 of the fixed-side driven plate 140, for example.

[0119] Further, in the above-described second embodiment, the sliding sleeve 160 is made of a resin material and the movable-side sleeve 152 is made of a metal material. That is, in the pulley device 130, the sliding sleeve 160 and the movable-side sleeve 152 are made of different materials from each other. Thereby, the pulley device 130 can improve the slidability between the sliding sleeve 160 and the movable-side sleeve 152 and between the concave cam portion 156 and the convex cam portion 165 and suppress wear deterioration. However, the pulley device 130 can also be configured such that the sliding sleeve 160 and the movable-side sleeve 152 are made of the same material as each other. Further, the pulley device 130 can also be configured such that the sliding sleeve 160 and the movable-side sleeve 152 are made of a material other than the resin material and the metal material, for example, a ceramic material.

[0120] Further, in each of the above embodiments, the pulley device 130 is configured by forming three concave cam portions 144, 156 and three convex cam portions 154, 165, respectively. However, the pulley device 130 may be configured by forming at least one set of the concave cam portions 144, 156 and the convex cam portions 154, 165.

[0121] Further, in the above embodiment, the centrifugal clutch 200 is configured to include a weight pressing body 216, a pressing body accommodating portion 224, and a pressing body receiving portion 224a, respectively. However, the centrifugal clutch 200 can also be configured by omitting the weight pressing body 216, the pressing body accommodating portion 224, and the pressing body receiving portion 224a. Further, in the centrifugal clutch 200, the pin sliding hole 222 is formed in an elongated hole shape in plan view. However, the centrifugal clutch 200 can also be configured such that the pin sliding hole 222 is formed in a circular shape in plan view.

[0122] In the above embodiment, the pulley device 130 is applied to the centrifugal clutch 200. However, the pulley device 130 can be widely applied to a mechanical device that transmits the driving force from a driving source such as an engine or an electric motor to an output shaft such as the drive shaft 145. Therefore, the pulley device 130 can be applied to, for example, a multi-plate clutch that transmits or blocks the rotational driving force by pressing two plates arranged opposite to each other, specifically, a plurality of friction plates provided with a friction material on the surface of a flat annular core and a plurality of clutch plates without a friction material against each other. Further, the pulley device 130 can also be provided as a part of the driving force transmission mechanism between the electric motor and the driving wheels in an electric vehicle that self-propels with an electric motor as a driving source.

Explanation of Signs

[0123] S… The annular gap formed between the main body portion and the outer cylindrical portion in the sliding sleeve 100… Power transmission mechanism, 101… Transmission 110… Drive pulley, 111… Crankshaft, 112… Fixed drive plate, 112a… Heat dissipation fins, 113… Movable drive plate, 114… Sleeve bearing, 115… Roller weight, 116… Lamp plate 120… V-belt 130… Pulley device, 131… Driven pulley 140… Fixed-side driven plate, 141… Fixed-side plate, 142… Fixed-side sleeve, 143… Cam formation protrusion, 144… Concave cam portion, 145… Drive shaft, 146a, 146b… Bearings 150… Movable-side driven plate, 151… Movable-side plate, 152… Movable-side sleeve, 152a… Cam connection portion 152b... inner peripheral surface 153… Sliding sleeve, 153a… Sleeve connection portion, 153b… Cam formation notch portion, 154… Convex cam portion, 155… Torque spring, 156… Concave cam portion, 157… Concave cam formation portion 160… Sliding sleeve, 161… Main body portion, 162… Outer cylindrical portion, 163… Spring receiving portion, 164… Plate fitting portion, 165… Convex cam portion, 166… Cam formation notch portion 200…Centrifugal clutch, 210…Drive plate, 211…Bottom, 212…Flange part, 213…Swing support pin, 213a…Mounting bolt, 214…Side plate, 215…Weight pressing body support part, 216…Weight pressing body, 217…Sleeve fitting hole, 220…Clutch weight, 221…Clutch shoe, 222…Pin sliding hole, 223…Connecting spring, 224…Pressing body housing part, 224a…Pressing body receiving part, 230…Clutch outer, 231…Cylindrical surface.

Claims

1. A fixed-side driven plate having a fixed-side plate projecting radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receiving a driving force from a driving source via a belt, and rotationally driven; A movable-side driven plate having a movable-side plate projecting radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiching the belt together with the fixed-side plate, and receiving a driving force from the driving source via the belt while approaching or separating from the fixed-side plate and rotationally driven; A sliding sleeve formed in a cylindrical shape and provided between the fixed-side sleeve and the movable-side sleeve, being displaced integrally with the movable-side sleeve and sliding relatively on the outer peripheral surface of the fixed-side sleeve; A concave cam portion formed by helically notching axially along one of the sliding sleeve and the fixed-side sleeve; A convex cam portion slidably fitted into the concave cam portion on the other of the sliding sleeve and the fixed-side sleeve; The concave cam portion or the convex cam portion formed on the sliding sleeve is formed to extend axially at one end of a cylindrical portion that slidably moves relatively on the outer peripheral surface of the fixed-side sleeve in the sliding sleeve, characterized pulley device.

2. In the pulley device according to claim 1, The concave cam portion or the convex cam portion formed on the sliding sleeve is characterized in that it is non-contact with the main body of the fixed-side sleeve.

3. In the pulley device according to claim 1 or claim 2, The movable-side sleeve is formed with a cam connecting portion formed in a concave or convex shape, The sliding sleeve is characterized in that a convex or concave sleeve connecting portion fitted to the cam connecting portion is formed.

4. In the pulley device according to any one of claims 1 to 3, The sliding sleeve and the fixed-side sleeve are made of different materials, characterized pulley device.

5. The pulley device according to any one of claims 1 to 4, A drive plate connected to the fixed-side sleeve and rotationally driven integrally with the fixed-side driven plate, A clutch outer that has a cylindrical surface provided concentrically with the drive plate on the outside of the drive plate and is connected to a drive shaft, A centrifugal clutch characterized by comprising a clutch shoe that extends along the circumferential direction of the drive plate and faces the cylindrical surface of the clutch outer, with one end side in the circumferential direction rotatably attached to the drive plate and the other end side displaced toward the cylindrical surface side of the clutch outer. **Claim 6** A fixed-side driven plate that has a fixed-side plate projecting radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receives a driving force from a drive source via a belt, and is rotationally driven, A movable-side driven plate that has a movable-side plate projecting radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiches the belt together with the fixed-side plate, and receives a driving force from the drive source via the belt while approaching or separating from the fixed-side plate and is rotationally driven, A sliding sleeve that is formed in a cylindrical shape and provided between the fixed-side sleeve and the movable-side sleeve, is provided so as not to be relatively displaceable with respect to the fixed-side sleeve, and slidably moves relative to the inner peripheral surface of the movable-side sleeve, A concave cam portion formed by helically notching along the axial direction in one of the sliding sleeve and the movable-side sleeve, A pulley device comprising a convex cam portion formed in the other of the sliding sleeve and the movable-side sleeve and slidably fitted into the concave cam portion, A drive plate that is connected to the fixed-side sleeve and is rotationally driven integrally with the fixed-side driven plate, A clutch outer that has a cylindrical surface provided concentrically with the drive plate on the outside of the drive plate and is connected to a drive shaft, A centrifugal clutch comprising a clutch shoe that extends along the circumferential direction of the drive plate and faces the cylindrical surface of the clutch outer, with one end side in the circumferential direction rotatably attached to the drive plate and the other end side displaced toward the cylindrical surface side of the clutch outer, The sliding sleeve is characterized by being provided on the drive plate. **Claim 7**: The centrifugal clutch according to claim 6, wherein the sliding sleeve has a cylindrical main body portion provided between the fixed-side sleeve and the movable-side sleeve, the concave cam portion or the convex cam portion is formed outside the main body portion of the sliding sleeve, and the centrifugal clutch is characterized in that. **Claim 8**: The centrifugal clutch according to claim 6 or claim 7, wherein the sliding sleeve and the movable-side sleeve are made of different materials from each other, and the centrifugal clutch is characterized in that. **Claim 9** a fixed-side driven plate having a fixed-side plate projecting radially outward in a flange shape on the outer peripheral surface of a fixed-side sleeve formed in a cylindrical shape, receiving a driving force from a driving source via a belt, and rotationally driving; a movable-side driven plate having a movable-side plate projecting radially outward in a flange shape on the outer peripheral surface of a movable-side sleeve formed in a cylindrical shape, sandwiching the belt together with the fixed-side plate, and rotationally driving while approaching or separating from the fixed-side plate by receiving the driving force from the driving source via the belt; a sliding sleeve formed in a cylindrical shape and provided between the fixed-side sleeve and the movable-side sleeve, formed in a cylindrical shape and provided so as not to be relatively displaceable with respect to the fixed-side sleeve and relatively slidable with respect to the movable-side sleeve; a concave cam portion formed by helically notching axially along one of the sliding sleeve and the movable-side sleeve; a pulley device including a convex cam portion formed on the other of the sliding sleeve and the movable-side sleeve and slidably fitted into the concave cam portion; a drive plate connected to the fixed-side sleeve and rotationally driving integrally with the fixed-side driven plate; a clutch outer having a cylindrical surface provided concentrically with the drive plate outside the drive plate and connected to a drive shaft; a clutch weight having a clutch shoe extending along the circumferential direction of the drive plate and facing the cylindrical surface of the clutch outer, with one end side in the circumferential direction rotatably attached to the drive plate and the other end side displaced toward the cylindrical surface side of the clutch outer; the sliding sleeve is provided on the drive plate, and the centrifugal clutch is characterized in that.

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