TW201643331A - Centrifugal clutch - Google Patents

Abstract

The present invention provides a centrifugal clutch capable of rapidly producing a coupling state while suppressing a sudden start of a follower side. A centrifugal clutch (200) is provided with: a first drive plate (210) that is rotationally driven directly by the driving force of an engine; and a second drive plate (230) that is brought into frictional contact with the first drive plate. The first drive plate (210) is provided with cam bodies (215) on supporting portions (214) that extend toward the second drive plate (230). The second drive plate (230) is rotationally driven in an integrated manner while allowing rotational displacement relative to the first drive plate (210) due to a disc spring (221) and is provided with clutch weights (240). Each of the cam bodies (215) has a first inclined surface (215c) that extends, while being inclined, outward and backward in the rotationally-driven direction of the first drive plate (210). On each of the clutch weights (240), a follower portion (242) that has a second inclined surface (242a) that is brought into surface contact with the first inclined surface (215c) is formed.

Description

Centrifugal clutch

The present invention relates to a centrifugal clutch that disconnects transmission of a rotational driving force to a driven side while the engine reaches a predetermined number of rotations, and transmits the rotational driving force to the driven side when the engine reaches a predetermined number of rotations.

Conventionally, in a device such as a two-wheeled motor vehicle or a brush cutter, a centrifugal clutch that transmits a rotational driving force to a driven side when a predetermined number of revolutions is used is used. For example, Patent Document 1 listed below discloses a centrifugal clutch in which a clutch weight is gradually displaced toward a clutch outer side in association with an increase in the number of revolutions of the engine. Further, Patent Document 2 listed below also discloses that a cam-shaped projection that is rotationally driven by an engine driving force is rotated by a cylindrical rotor, and a clutch shoe provided outside the rotor pushes a clutch outer cover (clutch outer) And the clutch is formed into a centrifugal clutch in a connected state.

Advanced technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2006-38124

Patent Document 2 Japanese Shigongzhao 42-15451

However, in the centrifugal clutch described in Patent Document 1, since the clutch weight gradually comes into frictional contact with the clutch cover as the number of engine revolutions increases, the time required for the number of engine revolutions to be added to the clutch forming connection state is long. There is a problem of low fuel efficiency. On the other hand, in the centrifugal clutch described in Patent Document 2, since the rotor is in a rolling contact with the cam-shaped projection after the cam-shaped projection is rotated, the clutch is brought into a connected state, so that the driven side abruptly operates to operate. A problem that is difficult to control.

The present invention has been made in order to solve the above problems, and an object of the invention is to provide a centrifugal clutch that can quickly form a coupled state while suppressing a sudden start of a driven side.

In order to achieve the above object, the present invention is characterized in that the first drive plate is provided to be driven to rotate integrally with the driven pulley by the driving force of the engine, and the annular second drive plate is disposed outside the first drive plate. And a frictional force that is rotatably driven in an integral manner while allowing relative rotational displacement of the first drive plate; the clutch weight is movably mounted on the second drive plate, and the second drive plate is driven by rotation The generated centrifugal force is displaced to the outside of the second drive plate, and has a clutch plate on the outer surface; the clutch cover has a cylindrical surface that frictionally contacts the clutch plate that is displaced to the outside of the second drive plate; and the cam body has a first inclined surface that is inclined to the outside of the first driving plate, and is provided in the first driving plate; and the driven portion has a second inclined surface that is in surface contact with the first inclined surface, and is provided on the clutch weight The first drive plate has a support portion that is formed to protrude from the first drive plate and faces the second drive plate, and the cam body is rotated toward the rotational direction of the first drive plate via the retaining pin. As supported on the support portion protruding from the first drive plate is formed.

According to the feature of the present invention configured as described above, the centrifugal clutch moves the second drive plate toward the rear side of the rotational drive direction when the clutch plate contacts the clutch cover after the first drive plate starts to rotate. The clutch cover is quickly pushed by the clutch plate by the driven portion rotating against the cam body. In other words, the centrifugal clutch secures the time required for the clutch plate to contact the clutch cover during the period from the start of the rotational driving of the first drive plate to the connected state, and rapidly switches to the link when the clutch plate contacts the clutch cover. status. By this action, the centrifugal clutch can quickly form a connected state while suppressing the sudden start of the driven side.

Further, in the centrifugal clutch of the present invention, since the clutch plate strongly presses against the clutch cover by the rotation of the driven portion against the cam body, even if the number of rotations is the same as that of the conventional centrifugal clutch, the rotational driving force from the engine can be used. The traditional centrifugal clutch has a lightweight clutch counterweight transmission. In other words, according to the centrifugal clutch of the present invention, since the clutch weight can be made lighter, it is possible to suppress the occurrence of a juke in the clutch connection, and it is possible to simplify, compact, and low-cost the centrifugal clutch. Chemical. Moreover, the weight of the clutch counterweight is set to be the same as that of the conventional centrifugal clutch, and this effect also means that the driving force that the centrifugal clutch can transmit is enlarged. Further, in the centrifugal clutch of the present invention, the contact surface between the first drive plate and the second drive plate is adjusted. The amount of rubbing force can also be appropriately adjusted to the time required for the clutch to form a connected state.

According to the present invention, since the centrifugal clutch is rotatably provided in the rotational driving direction of the first drive plate, even if the clutch plate that is in frictional contact with the clutch cover is worn, the cam body is rotated rearward in the rotational direction. When the side is rotated, the follower portion can be brought into contact with the surface, and the clutch plate can be stably pressed against the clutch cover for a long period of time. Further, in the centrifugal clutch of the present invention, the rotation angle of the cam body is increased as the friction of the clutch plate is increased, and the first inclined surface is brought close to the tangential direction, so that the pressing force of the clutch plate to the clutch cover is increased. By this action, even in the case where the friction surface of the clutch plate is smoothed, the centrifugal clutch can suppress the reduction of the frictional force by the pressing force of the clutch cover against the clutch cover. Further, in the centrifugal clutch of the present invention, since the cam body is supported by the holding pin, it can be rotatably held by the first drive plate with excellent precision, and maintenance work such as replacement of the cam body or the retaining pin can be easily performed.

According to another aspect of the invention, in the centrifugal clutch, the holding pins are rotatably fitted to a shaft portion formed on the support portion of the first drive plate to support the cam body, and the shaft portion is provided on the shaft portion. A planar contact portion that is in contact with the second drive plate at one end, and the contact portion contacts only the portion of the planar contact portion to contact the second drive plate so as to rotate on the second drive plate.

According to another feature of the present invention configured as described above, the centrifugal clutch has a contact portion formed in a planar shape on the holding pin, and only a part of the contact portion forming the planar surface is in contact with the second driving plate. The holding pin rotates on the second driving plate, and when the second driving plate relatively rotates the first driving plate, the friction between the two is reduced, and the mark and the card mark between the two are suppressed (the pre-marking stage) The frictional resistance rises) or wear (abnormal wear).

According to still another aspect of the invention, in the centrifugal clutch, the first drive plate causes the support portion to incline toward the second drive plate.

According to still another feature of the present invention constructed in this manner, the centrifugal clutch can tilt the holding pin to the second driving plate, and can simply contact only a part of the contact portion with the second driving plate.

The centrifugal clutch may be configured such that the contact portion is inclined with respect to the shaft portion, the contact portion itself is formed as an inclined surface (for example, the thickness is changed), and the support portion hole portion in which the shaft portion of the holding pin is fitted is inclined. Or tilting the rotation surface of the second driving plate for rotating the contact portion instead of tilting the support portion of the first driving plate or tilting the support portion of the first driving plate Various configurations of the centrifugal clutch described above are added to the outside.

According to still another aspect of the invention, in the centrifugal clutch, the first drive plate is configured to incline the second drive plate by performing heat treatment on at least the support portion.

According to another feature of the present invention which is configured in this manner, the centrifugal clutch applies heat treatment to the support portion, and the second drive plate is inclined by the heat treatment. Therefore, it is not necessary to form the support portion into a tilting process, and the manufacturing steps can be performed. Simplified. In addition, in this case, the heat treatment applied to the support portion is not only hardening to the general quenching treatment inside the support portion (including integral quenching and partial quenching), but also surface hardening treatment (carburizing quenching, high-frequency quenching, flame quenching, Nitriding treatment, laser quenching, etc.).

100‧‧‧Power transmission mechanism

101‧‧‧Transmission

110‧‧‧ drive pulley

111‧‧‧ crankshaft

112‧‧‧Fixed drive board

112a‧‧‧Heatsink

113‧‧‧ movable drive board

114‧‧‧Sleeve bearing

115‧‧‧ Roller counterweight

116‧‧‧ slope board

120‧‧‧V belt

130‧‧‧Driven pulley

131‧‧‧Fixed drive board

132‧‧‧Driven sleeve

133‧‧‧ drive shaft

134‧‧‧ movable driven board

135‧‧‧Torque spring

200‧‧‧ centrifugal clutch

210‧‧‧1st drive board

211‧‧‧ bottom

212‧‧‧through holes

213‧‧‧ Tube

214‧‧‧Support Department

214a‧‧‧through hole

215‧‧‧ cam body

215a‧‧‧ base

215b‧‧‧through hole

215c‧‧‧1st inclined surface

215d‧‧‧ arc surface

216‧‧‧ Keep selling

216a‧‧‧Axis

216b‧‧‧Contacts

220‧‧‧ fixture

221‧‧‧ coil spring

230‧‧‧2nd drive board

231‧‧‧ ring plate

232‧‧‧through holes

233‧‧‧Support

240‧‧‧Clutch weight

241‧‧‧Connected spring

242‧‧‧Responsible Department

242a‧‧‧2nd inclined surface

243‧‧‧Clutch piece

250‧‧‧Clutch cover

251‧‧‧Cylinder

Fig. 1 is a plan sectional view schematically showing the configuration of a power transmission mechanism including a centrifugal clutch of the present invention.

Fig. 2 is a side view of the centrifugal clutch viewed from line 2-2 shown in Fig. 1.

(A) and (B) are external configuration diagrams of the first drive plate and the second drive plate of the centrifugal clutch of Figs. 1 and 2, respectively, wherein (A) shows the first drive. (A) is a perspective view showing an assembled state of the first drive plate and the second drive plate.

Fig. 4 is a partially enlarged view showing the inside of a dotted circle of the centrifugal clutch shown in Fig. 1 in an enlarged manner.

FIGS. 5(A) to 5(D) are diagrams showing the external configuration of the cam body shown in the centrifugal clutch shown in FIGS. 1 and 2 and the state in which it is assembled to the first drive plate, wherein (A) is a slave. (B) is a perspective view showing a state before assembly of the cam body from the inside of the first drive plate, and (C) is a view showing a state in which the cam body is assembled from the outside of the first drive plate. (D) A perspective view showing the assembled state of the cam body from the inside of the first drive plate.

Fig. 6 is a partially enlarged view showing the cam body of the centrifugal clutch shown in Fig. 2 in a state in which the clutch plate is not in contact with the clutch cover.

Fig. 7 is a partially enlarged view showing a state in which the cam body and the driven portion in a connected state in contact with the clutch cover are in a state in which the clutch plate of the centrifugal clutch shown in Fig. 6 is in a state of no wear.

Fig. 8 is a partially enlarged view showing a state in which the clutch body is in contact with the driven portion in a state in which the clutch body is in contact with the clutch cover in a state in which the clutch plate in the centrifugal clutch of Fig. 6 is wound by about 1 mm.

Fig. 9 is a partially enlarged view showing a state in which the cam member is in contact with the driven portion in a connected state in which the cam member is in contact with the clutch cover in a state in which the clutch plate in the centrifugal clutch of Fig. 6 is wound by about 2 mm.

Fig. 10 is a partially enlarged view showing a configuration of a centrifugal clutch according to a modification of the present invention, which is enlarged in accordance with a configuration of a portion corresponding to a broken line shown in Fig. 1.

Fig. 11 is a partially enlarged plan view showing a configuration of a centrifugal clutch according to another modification of the present invention, which is enlarged in correspondence with a portion corresponding to a broken line shown in Fig. 1.

Fig. 12 is a partially enlarged view showing the configuration of a centrifugal clutch according to still another modification of the present invention, which is enlarged in accordance with a portion corresponding to a broken line circle shown in Fig. 1.

Fig. 13 is a partially enlarged plan view showing a configuration of a centrifugal clutch according to another modification of the present invention, which is enlarged in correspondence with a portion corresponding to a broken line shown in Fig. 1.

[Embodiment of the Invention]

Hereinafter, an embodiment of the centrifugal clutch of the present invention will be described while referring to the drawings. Fig. 1 is a cross-sectional view showing the power transmission mechanism 100 including the centrifugal clutch 200 of the present invention. In addition, Fig. 2 is a side view of the centrifugal clutch 200 as seen from line 2-2 shown in Fig. 1. The power transmission mechanism 100 including the centrifugal clutch 200 is mainly provided between the engine and the rear wheel as the drive wheel in the automatic two-wheeled vehicle such as a Scooter locomotive, and automatically changes the reduction ratio with respect to the number of engine revolutions. A mechanical device that transmits a rotational driving force to the rear wheel or is cut.

(Configuration of the centrifugal clutch 200)

The power transmission mechanism 100 mainly includes a transmission 101 and a centrifugal clutch 200, respectively. The transmission 101 is a mechanical device that transmits a rotational driving force from an engine (not shown) to the centrifugal clutch 200 by stepless deceleration, and mainly includes a drive pulley 110, a V-belt 120, and a driven pulley 130. Wherein, the drive pulley 110 is arranged to extend from the lead The crankshaft 111 of the engine is directly driven by the rotational driving force of the engine, and the main components thereof are respectively provided with a fixed driving plate 112 and a movable driving plate 113.

The fixed drive plate 112 is a unit that is rotationally driven in a state in which the V-belt 120 is sandwiched by the movable drive plate 113, and is formed of a metal material into a conical tubular shape. The fixed drive plate 112 is fixedly attached to the crankshaft 111 with the convex side facing the side of the movable drive plate 113 (engine side). That is, the fixed drive plate 112 is always rotationally driven integrally with the crankshaft 111. Further, a plurality of fins 112a are radially provided on the concave side surface of the fixed driving plate 112.

The movable drive plate 113 is a unit that is rotationally driven in a state in which the V-belt 120 is sandwiched by the fixed drive plate 112, and is formed of a metal material into a conical tubular shape. The movable driving plate 113 is attached to the crank shaft 111 in a direction in which the convex side faces the fixed driving plate 112. In this case, the movable driving plate 113 is mounted on the sleeve bearing 114 fixedly fitted to the crank shaft 111 via the impregnated bushing, and is slidably mounted in the sleeve bearing 114 in the axial and circumferential directions, respectively. .

On the other hand, the concave side surface of the movable driving plate 113 is provided with a plurality of roller weights 115 in a state of being pressed by a ramp plate 116. The roller weight 115 is displaced radially outward by the increase in the number of rotations of the movable driving plate 113, whereby the assembly that cooperates with the slope plate 116 to push the movable driving plate 113 toward the fixed driving plate 112 side is made of metal. The material is formed into a cylindrical shape. Further, the slope plate 116 is a unit that presses the roller weight 115 toward the movable drive plate 113 side, and is configured by bending the metal plate toward the movable drive plate 113 side.

The V-belt 120 is a member for transmitting the rotational driving force of the drive pulley 110 to the driven pulley 130, and is formed of a resin-coated core wire to form an endless loop. The V-belt 120 is disposed between the fixed driving plate 112 and the movable driving plate 113 and between the fixed driven plate 131 and the movable driven plate 134 of the driven pulley 130, and is disposed around the driving pulley 110 and the driven pulley 130. between.

The driven pulley 130 is a mechanism that is rotationally driven by the rotational driving force of the engine via the drive pulley 110 and the V-belt 120, and mainly includes a fixed driven plate 131 and a movable driven plate 134.

The fixed driven plate 131 is a unit that is rotationally driven in a state in which the V-belt 120 is held together with the movable driven plate 134, and is formed of a metal material into a conical tubular shape. The solid The fixed drive plate 131 is fixedly mounted on the driven sleeve 132 with the convex side facing the side of the movable driven plate 134.

The driven sleeve 132 is a metal cylindrical assembly that is rotationally driven integrally with the fixed driven plate 131, and is attached to the drive shaft 133 in a relatively rotatable manner via bearings. The drive shaft 133 is a metal rotating shaft body, and the rear wheel of the motorcycle in which the power transmission mechanism 100 is mounted is driven via a transmission (not shown). In this case, the rear wheel train of the motorcycle is mounted on one side (right side of the drawing) of the drive shaft 133.

The movable driven plate 134 is configured to be rotationally driven in a state in which the V-belt 120 is sandwiched by the fixed driven plate 131, and is formed of a metal material into a conical tubular shape. The movable driven plate 134 is fitted to the driven sleeve 132 in a state in which the convex side surface is slidable in the axial direction in a direction opposite to the fixed driven plate 131.

On the other hand, the concave side surface of the movable driven plate 134 is provided with a torsion spring 135 between the first drive plate 210 of the centrifugal clutch 200. The torsion spring 135 is a coil spring that elastically presses the movable driven plate 134 toward the fixed driven plate 131 side. That is, the transmission 101 is defined by the diameter of the V-belt 120 that is defined by the spacing between the fixed drive plate 112 and the movable drive plate 113, and the distance between the driven plate 131 and the movable driven plate 134. The magnitude relationship of the diameter of the V-belt 120 is clamped, and the number of engine revolutions is shifted in a stepless manner. Further, a centrifugal clutch 200 is provided on each of the front end portions of the driven sleeve 132 and the drive shaft 133.

The centrifugal clutch 200 is a mechanical device that transmits or disengages the engine rotational driving force transmitted via the transmission 101 to the drive shaft 133, and mainly includes a first drive plate 210, a second drive plate 230, and a clutch weight. (clutch weight) 240 and clutch outer 250.

The first drive plate 210 is a unit that is rotationally driven integrally with the driven sleeve 132, and is formed of a metal material having a bottomed cylindrical shape. More specifically, as shown in FIGS. 3(A) and (B), the first drive plate 210 has a through hole 212 through which the driven sleeve 132 is inserted in the center portion of the flat bottom portion 211, and is erected in The front end portions of the tubular portion 213 around the bottom portion 211 are respectively provided with three support portions 214 at equal intervals in the circumferential direction.

The support portion 214 is a portion that presses the surface of the second drive plate 230 via a holding pin 216 to be described later and supports the cam body 215, and is radially outward from the front end portion of the tubular portion 213. Protruding to form a sheet. That is, the support portion 214 is provided in a state of being opposed to the second drive plate 230. In this case, as shown in FIG. 4, in order to improve the wear resistance, the support portion 214 is subjected to a heat treatment (quenching treatment), and the quenching treatment causes the surface of the opposite second driving plate 230 to be inclined. Non-parallel state. In this way, the support portion 214 can make only a part of the contact portion 216b of the holding pin 216 in contact with the surface of the second drive plate 230. Further, the support portion 214 is formed with a through hole 214a, and the holding pin 216 is slidably disposed in the through hole 214a in a state in which the cam body 215 is inserted.

The cam body 215 is a unit for pressing a clutch weight 240 to be described later on the clutch housing 250 side, and is formed of a metal material (for example, carbon steel or an iron-based sintered material) in a plate shape. More specifically, as shown in FIGS. 5(A) to (D), respectively, the cam body 215 is formed with a through hole 215b through which the holding pin 216 passes, in the central portion of the plate-like base portion 215a, and at the base portion. A portion of the outer peripheral portion of the outer circumferential portion 215a that protrudes in the orthogonal direction and has a thickness increased is formed with a first inclined surface 215c and an arcuate surface 215d. In this case, the through hole 215b is formed to have an inner diameter that allows the retaining pin 216 to slide. That is, the through hole 215b is formed by forming a dimensional tolerance for the so-called gap fitting of the holding pin 216 (that is, a gap is left between the holding pin 216 and the through hole 215b).

The first inclined surface 215 c is a flat surface that slides the second inclined surface 242 a of the clutch weight 240 in a surface contact state, and is formed toward the first driving plate 210 toward the rear of the first driving plate 210 in the rotational driving direction. The outer side extends obliquely. Further, the circular arc surface 215d extends from the rear end portion of the first inclined surface 215c to form an arc shape. Further, the first inclined surface 215c and the circular arc surface 215d are formed thicker than the thickness of the base portion 215a, but this is for the purpose of easily and accurately assembling the cam body 215 to the support portion 214. Therefore, the first inclined surface 215c and the circular arc surface 215d may be formed to have the same thickness as the thickness of the base portion 215a.

The holding pin 216 is a metal rod-shaped member for attaching the cam body 215 to the support portion 214 in a rotatable state, and is mainly composed of a shaft portion 216a and a contact portion 216b. The shaft portion 216a is a rod-shaped portion that slidably passes through the through hole 214a of the support portion 214 and the through hole 215b of the cam body 215. Further, the contact portion 216b is a portion that is in rotational contact with the second drive plate 230, and is formed in a disk shape protruding from one end portion of the shaft portion 216a. The holding pin 216 passes through the cam body 215 and the support portion 214 in a state of being disposed on the support portion 214, and is disposed in a direction in which the first inclined surface 215c of the cam body 215 is rotated rearward in the driving direction of the first driving plate 210. It extends obliquely to the outside of the first drive plate 210.

Next, the first drive plate 210 has the front end portion of the tubular portion 213 rotatably fitted into the through hole 232 of the second drive plate 230. In this case, the outer peripheral portion of the tubular portion 213 of the first drive plate 210 is fitted with an annular flat plate-shaped jig 220. A coil spring 221 is fitted between the jig 220 and the second drive plate 230. The coil spring 221 is an elastic body that presses and frictionally contacts the support portion 214 of the first drive plate 210 and the second drive plate 230, and is formed of a ring-shaped flat spring steel in a tapered shape.

The second drive plate 230 is a unit that allows the first drive plate 210 to be rotationally driven integrally while being rotationally displaced, and is formed of a metal material to form a ring-shaped flat plate. More specifically, the second drive plate 230 is formed with a through hole 232 in which the tubular portion 213 of the first drive plate 210 is slidably fitted in the center portion of the plate-shaped annular plate 231, and is formed on the annular plate 231. Three fulcrum pins 233 are respectively provided in the erect state at equal intervals in the circumferential direction. In this case, the contact portion 216b of the aforementioned holding pin 216 is rotatable on the flat plate portion abutting the edge portion of the through hole 232. The fulcrum pin 233 is a member for rotatably supporting the clutch weight 240 and is composed of a metal rod.

The clutch weight 240 is a component that transmits or receives the rotational driving force from the engine to the drive shaft 133 or is cut by the clutch cover 243 in contact with or away from the clutch cover 250 in accordance with the number of rotations of the second drive plate 230. The material (for example, zinc material) is formed to have a shape that is curved and curved in the circumferential direction of the second drive plate 230. The clutch weight 240 is rotatably supported by the fulcrum pin 233 on one end side, and the clutch weights 240 adjacent to each other of the three clutch weights 240 are connected to each other by the connection spring 241, and are driven toward the second. The inner side of the plate 230 is rotated in such a manner as to be pulled. Further, in order to easily understand the configuration of the clutch weight 240, in the second drawing, a part of the two clutch weights 240 of the three clutch weights 240 are cut and shown from faces having different thickness directions.

In the inner circumferential surface of each of the clutch weights 240, the portion facing the cam body 215 of the first drive plate 210, more specifically, the inner surface of the surface below the spring 241 (the surface on the rear side in the drawing) is recessed. The driven portion 242 is formed in a concave shape. The driven portion 242 is a portion for displacing the clutch weight 240 toward the clutch housing 250 side in cooperation with the cam body 215, and is constituted by a second inclined surface 242a having a flat inclined surface similar to the first inclined surface 215c. . The The driven portion 242 is formed such that the thickness of the second inclined surface 242a is wider than the thickness of the first inclined surface 215c, and the second inclined surface 242a is in surface contact with the first inclined surface 215c. Further, the follower portion 242 constitutes the second inclined surface 242a by a material which is more likely to be worn than the cam body 215 constituting the first inclined surface 215c. In the present embodiment, the driven portion 242 is made of the same metal material (for example, zinc material) as the clutch weight 240. Further, the follower portion 242 is formed such that a portion deeper than the second inclined surface 242a is recessed in an arc shape to secure a space required for the rotation of the cam body 215.

On the other hand, a clutch plate 243 is provided on each of the outer circumferential surfaces of the clutch weights 240. The clutch plate 243 is configured to expand the frictional force on the inner circumferential surface of the clutch outer cover 250, and is formed of a friction material extending into a circular arc shape.

The clutch housing 250 is a unit that is rotationally driven integrally with the drive shaft 133, and is configured by a cup-shaped body made of a metal material that covers the outer peripheral surface of the clutch weight 240 from the first drive plate 210. That is, the clutch housing 250 is constituted by a cylindrical surface 251 which is in frictional contact with the clutch plate 243 of the clutch weight 240 displaced to the outer peripheral side of the second drive plate 230.

(Operation of the centrifugal clutch 200)

Next, the operation of the centrifugal clutch 200 configured as described above will be described. The centrifugal clutch 200 is disposed between a engine of a motorcycle (for example, a speed-up locomotive) and a rear wheel as a drive wheel to function as a part of the power transmission mechanism 100. First, in the engine idle (idle speed) state, as shown in Fig. 6, the centrifugal clutch 200 cuts off the driving force transmission between the engine and the drive shaft 133. Specifically, the centrifugal clutch 200 integrally drives the first drive plate 210 and the second drive plate 230 that is in frictional contact with the first drive plate 210 via the coil spring 221 by the engine rotational driving force transmitted via the transmission 101, and is integrally driven. The clutch weight 240 is rotationally driven. In addition, in FIG. 6, in order to clarify the contact state of the cam body 215 and the follower part 242, the connection spring 241 is abbreviate|omitted.

However, in this case, since the centrifugal force of the centrifugal clutch 200 acting on the clutch weight 240 is smaller than the elastic force (tension) of the coupling spring 241, the clutch plate 243 does not contact the cylindrical surface 251 of the clutch housing 250, and the engine rotational driving force is not It is transmitted to the drive shaft 133. In this case, since the second inclined surface 242a is pressed against the first inclined surface 215c by the elastic force (tension) of the connection spring 241, the cam body 215 and the driven portion 242 maintain the surface contact state.

On the other hand, the centrifugal clutch 200 transmits the engine rotational driving force to the drive shaft 133 in accordance with the number of engine revolutions generated by the acceleration operation of the automatic two-wheeled rider. Specifically, as shown in FIG. 7, the centrifugal clutch 200 increases the number of revolutions of the engine, so that the centrifugal force acting on the clutch weight 240 is greater than the elastic force (tension) of the coupling spring 241, and the clutch weight 240 is used as a fulcrum pin. The 233 is rotated toward the outside in the radial direction. That is, the centrifugal clutch 200, as the number of revolutions of the engine increases, causes the clutch weight 240 to resist the elastic force (pull force) of the coupling spring 241, and is rotationally displaced toward the cylindrical surface 251 side of the clutch housing 250, and as a result, the clutch disc is caused. 243 is in contact with the cylindrical surface 251. In addition, in FIG. 7, in order to clarify the contact state of the cam body 215 and the follower part 242, the connection spring 241 is abbreviate|omitted. In addition, in FIGS. 2 and 7, the rotational driving direction of the centrifugal clutch 200 is indicated by a broken line arrow.

When the clutch plate 243 comes into contact with the cylindrical surface 251, the clutch weight 240 receives a reaction force in a direction opposite to the rotational driving direction via the clutch plate 243. In this case, the first driving plate 210 and the second driving plate 230 are frictionally contacted by the elastic force (pushing force) provided by the coil spring 221, but the aforementioned reaction force of the clutch weight 240 exceeds the frictional contact force. At this time, the second drive plate 230 is relatively displaced in the opposite direction to the rotational drive direction of the first drive plate 210. With this action, since the clutch weight 240 supported by the second drive plate 230 is relatively displaced in the opposite direction to the rotational drive direction of the first drive plate 210, the first inclined surface 215c of the cam body 215 is in surface contact. The second inclined surface 242a of the driven portion 242 is displaced along the first inclined surface 215c.

In this case, the first inclined surface 215 c of the cam body 215 is formed to extend rearward in the rotational driving direction of the first driving plate 210 and to the outside of the first driving plate 210 . Further, the second inclined surface 242a of the driven portion 242 is formed on the same plane as the first inclined surface 215c, and is in surface contact with the first inclined surface 215c. With these configurations, the clutch weight 240 is pressed toward the radially outer clutch housing 250 side as the second inclined surface 242a slides on the first inclined surface 215c, and the clutch plate 243 is pressed against the cylindrical portion 251. . As a result, after the clutch plate 243 contacts the cylindrical surface 251 of the clutch housing 250, the centrifugal clutch 200 presses the clutch plate 243 against the cylindrical surface 251 in a very short time (in other words, in an instant) to form a rotary drive of the engine. The force is completely transmitted to the connected state of the drive shaft 133.

Further, when the second drive plate 230 relatively rotates the first drive plate 210, The holding pin 216 is also relatively displaced with respect to the second driving plate 230 in the circumferential direction of the second driving plate 230 together with the first driving plate 210. In this case, the holding pin 216 pushes only a part of the peripheral edge portion of the contact portion 216b to the second driving plate 230. By this action, the holding pin 216 is rotated on the second driving plate 230 in accordance with the relative displacement of the second driving plate 230 as indicated by the dotted arrow in FIG. Therefore, compared with the case where the contact portion 216b of the holding pin 216 is in contact with the second driving plate 230, the frictional resistance (sliding resistance) of the centrifugal clutch 200 is small, and the clutch plate 243 can be smoothly pushed against the cylindrical surface 251. Further, abrasion or heat generation between the contact portion 216b and the second drive plate 230 can be suppressed.

In the connected state in which the rotational driving force of the engine is completely transmitted to the drive shaft 133, the centrifugal clutch 200 maintains the state in which the second inclined surface 242a of the driven portion 242 is pressed against the first inclined surface 215c of the cam body 215. The driving plate 210 and the second driving plate 230 are rotationally driven in an integrated manner, and the clutch plate 243 is pressed against the cylindrical surface 251 of the clutch housing 250, so that the second driving plate 230 and the clutch housing 250 are integrated. Rotate the drive. By this action, the automatic two-wheeled vehicle can drive the rear wheel to be driven by the rotational driving force of the engine.

On the other hand, in the case where the number of rotations of the engine is reduced, the centrifugal clutch 200 cuts off the transmission of the engine rotational driving force to the drive shaft 133. Specifically, the centrifugal clutch 200 causes the centrifugal force acting on the clutch weight 240 to be smaller than the elastic force (pull force) of the coupling spring 241 as the number of engine rotations decreases, and the clutch weight 240 rotates radially inwardly around the fulcrum pin 233. Displacement.

In this case, the second inclined surface 242a of the driven portion 242 of the clutch weight 240 slides on the first inclined surface 215c of the cam body 215 due to the elastic force (tension) of the connecting spring 241, so the second driving plate 230 will relatively rotationally displace the first drive plate 210 toward the front in the rotational direction of the first drive plate 210. By this action, the second drive plate 230 returns the first drive plate 210 to the original position (the position at the time of the idling). That is, the centrifugal clutch 200 causes the clutch plate 243 not to contact the clutch housing 250 to form an open state in which the rotational driving force is not transmitted.

When the rotational driving force is switched to the OFF state, as shown by the dotted arrow in FIG. 4, only a part of the peripheral edge portion of the contact portion 216b contacts the second driving plate 230, so that the second driving plate 230 is opposed to each other. Displacement, the retaining pin 216 will rotate on the second drive plate 230. By this action, in the centrifugal clutch 200, the frictional resistance (sliding resistance) is reduced and the clutch plate 243 can be smoothly separated as compared with the case where the contact portion 216b of the holding pin 216 is in contact with the second driving plate 230. The cylindrical surface 251 can suppress abrasion or heat generation between the contact portion 216b and the second drive plate 230.

Further, when the clutch piece 243 is reduced in thickness due to abrasion, the centrifugal clutch 200 can also quickly press the clutch piece 243 against the cylindrical surface 251 of the clutch cover 250 to form a coupled state. In the centrifugal clutch 200, as shown in Figs. 8 and 9, respectively, the cam body 215 is rotatably attached to the support portion 214, and the second inclined surface 242a is paired even by the wear of the clutch plate 243. When the angle of the first inclined surface 215c is changed, the second inclined surface 242a can be pressed against the first inclined surface 215c, and the orientation of the cam body 215 can be changed to maintain the first inclined surface 215c and the second inclined surface 242a. Face contact. In addition, in FIG. 8 and FIG. 9, in order to clarify the contact state of the cam body 215 and the follower part 242, the connection spring 241 is abbreviate|omitted. Further, in FIGS. 8 and 9, the rotational driving directions of the centrifugal clutch 200 are indicated by dotted arrows, respectively.

As can be understood from the above-described operation, in the above-described embodiment, after the first drive plate 210 is rotationally driven, the centrifugal clutch 200 contacts the clutch cover 250 through the clutch plate 243, and the second drive plate 230 rotates the first drive plate 210. When the driving direction moves rearward, the clutch piece 243 rapidly pushes the clutch housing 250 by the driven portion 242 rotating against the cam body 215. In other words, the centrifugal clutch 200 ensures the time required for the clutch plate 243 to come into contact with the clutch cover 250 during the period from the start of the rotational driving of the first drive plate 210 to the formation of the coupled state, and the clutch plate 243 contacts the clutch cover 250. At the same time, it will quickly switch to the link state. By this action, the centrifugal clutch 200 can quickly form a connected state while suppressing the sudden start of the driven side of the drive wheel or the like.

Further, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In the following various modifications, the same components as those in the above-described embodiments are denoted by the same reference numerals, and their description is omitted.

For example, in the above-described embodiment, the cam body 215 is rotatably attached to the holding pin 216 to rotate in the rotational driving direction of the first driving plate 210, and the holding pin 216 is rotatably attached to the first driving plate 210. . However, the cam body 215 may be configured to rotate in the rotational driving direction of the first drive plate 210. Therefore, the cam body 215 can also be rotatably attached to, for example, a round rod-shaped pin member integrally formed on the first drive plate 210.

Further, in the above embodiment, the holding pin 216 is constructed as shown in Fig. 4 By forming the support portion 214 in a non-parallel state in which the second drive plate 230 is inclined, only a part of the contact portion 216b contacts the second drive plate 230. However, the holding pin 216 may be configured such that only a part of the contact portion 216b contacts the second driving plate 230, and is not necessarily limited to the above embodiment. In this case, what is referred to as only a portion of the contact portion 216b does not necessarily mean a point of contact on a strictly defined basis. The second driving plate 230 may be inclined as long as the contact portion 216b is rotatable on the second driving plate 230. In other words, in other words, the plate surface of the contact portion 216b that is in contact with the second driving plate 230 may have a portion having a large pressing force.

Therefore, the centrifugal clutch 200 may be formed such that the contact portion 216b of the holding pin 216 is inclined with respect to the shaft portion 216a as shown in Fig. 10, or may be formed as an inclined surface of the contact portion 216b itself as shown in Fig. 11 . (For example, make the thickness change). Further, as shown in Fig. 12, the centrifugal clutch 200 may be configured such that the through hole 214a of the support portion 214 in which the shaft portion 216a of the holding pin 216 is fitted is formed in an inclined state. Further, as shown in Fig. 13, the centrifugal clutch 200 may be configured such that the rotation surface of the second drive plate 230 for rotating the contact portion 216b of the holding pin 216 is inclined.

Further, in the above embodiment, the centrifugal clutch 200 forms a non-parallel state in which the second drive plate 230 is inclined by applying heat treatment to the support portion 214. However, it is a matter of course that the method of forming the support portion 214 in the non-parallel state in which the second driving plate 230 is inclined is also a method other than heat treatment. Specifically, the support portion 214 can be formed into a non-parallel state in which the second drive plate 230 is inclined by mechanical processing such as cutting or plastic working.

Next, in the above embodiment, the centrifugal clutch 200 is constituted by three cam bodies 215 provided on the peripheral portion of the first drive plate 210. However, the cam body 215 may be provided in accordance with the number of the clutch weights 240. Therefore, the number of the cam bodies 215 and the driven portions 242 provided in the first drive plate 210 and the clutch weight 240 may be at least one, that is, one or more pairs may be provided.

Further, in the above embodiment, the first drive plate 210 and the second drive plate 230 are configured to be frictionally contacted by the coil spring 221. With this design, the frictional force setting of the centrifugal clutch 200 is easier than that in the case where the first drive plate 210 and the second drive plate 230 are fitted to each other to be frictionally contacted, and the friction can be stably generated over a long period of time. force. However, the first driving plate 210 and the second driving plate 230 are required to allow the second driving plate 230 to rotate relative to the first driving plate 210. The one side can be rotated in an integral manner for frictional contact.

Therefore, the first driving plate 210 and the second driving plate 230 may be configured such that the elastic body other than the coil spring and the coil spring that presses at least one of the first driving plate 210 and the second driving plate 230 is pressed, for example, a spiral Springs or leaf springs, even rubber sheets, etc., make frictional contact. Further, the centrifugal clutch 200 may be omitted from the elastic body, and the first drive plate 210 and the second drive plate 230 may be directly fitted to each other in a friction-slidable manner. In this case, the centrifugal clutch 200 can also adjust the time required for the clutch to be connected to the state by adjusting the frictional force of the contact surface between the first drive plate 210 and the second drive plate 230.

In the above-described embodiment, the centrifugal clutch 200 is made of a material that is more likely to be worn than the cam body 215 that constitutes the first inclined surface 215c. Specifically, the second inclined surface 242a of the driven portion 242 is formed using a zinc material. According to this configuration, the second inclined surface 242a is made of a material that is easily worn away from the first inclined surface 215c, so that the second inclined surface 242a is more likely to be worn than the first inclined surface 215c. In this case, since the second inclined surface 242a is formed in the clutch weight 240 including the clutch plate 243, it can be updated when the clutch weight 240 is replaced by the clutch plate 243 being worn. In other words, the centrifugal clutch 200 can be replaced by the clutch weight 240 that is applied by the clutch plate 243, and the second inclined surface 242a can be replaced with a new one, thereby reducing the burden of maintenance. In this case, the centrifugal clutch 200 is configured to have the second inclined surface 242a and the first inclined surface 215c of the same material, and is subjected to surface hardening treatment such as heat treatment or coating on the first inclined surface 215c to be worn. The property is improved more than the second inclined surface 242a.

200‧‧‧ centrifugal clutch

210‧‧‧1st drive board

211‧‧‧ bottom

212‧‧‧through holes

213‧‧‧ Tube

214‧‧‧Support Department

215‧‧‧ cam body

215b‧‧‧through hole

215c‧‧‧1st inclined surface

215d‧‧‧ arc surface

216a‧‧‧Axis

230‧‧‧2nd drive board

231‧‧‧ ring plate

232‧‧‧through holes

233‧‧‧Support

240‧‧‧Clutch weight

241‧‧‧Connected spring

242‧‧‧Responsible Department

242a‧‧‧2nd inclined surface

243‧‧‧Clutch piece

250‧‧‧Clutch cover

251‧‧‧Cylinder

Claims (4)

A centrifugal clutch includes: a first drive plate that is driven to rotate integrally with a driven pulley by a driving force of an engine; and an annular second drive plate disposed outside the first drive plate and allowed to allow The first drive plate is in contact with the rotational displacement of the first drive plate in a rotationally rotatable manner; the clutch weight is movably mounted on the second drive plate, and the centrifugal force generated by the rotational drive of the second drive plate is generated. Displaceing to the outside of the second drive plate, and having a clutch plate on the outer surface; the clutch cover has a cylindrical surface that frictionally contacts the clutch plate displaced to the outside of the second drive plate; and the cam body has a first inclined surface that is inclined to the outside of the first driving plate, and is provided in the first driving plate; and the driven portion has a second inclined surface that is in surface contact with the first inclined surface, and is provided in the clutch In the weight, the first drive plate has a support portion that is formed to protrude from the first drive plate and faces the second drive plate, and the cam system is via the cam system. The holding pin is rotatably supported by the support portion formed to protrude from the first drive plate in a rotational direction of the first drive plate. The centrifugal clutch according to the first aspect of the invention, wherein the holding pin is rotatably fitted to a shaft portion formed on the support portion of the first drive plate to support the cam body, and is provided on the centrifugal clutch One end of the shaft portion and a planar contact portion that is in contact with the second drive plate, and the contact portion is formed to contact only a part of the contact portion that forms the planar surface so as to rotate on the second drive plate. 2 drive board. The centrifugal clutch according to the second aspect of the invention, wherein the first driving plate is configured such that the support portion inclines the second driving plate. The centrifugal clutch according to claim 3, wherein the first driving plate is configured to incline the second driving plate by performing heat treatment on at least the support portion.