JP4309889B2 - Centrifugal clutch - Google Patents

Description

  The present invention relates to a centrifugal clutch capable of minimizing the number of centrifugal weights in a belt type continuously variable transmission such as a motorcycle.

  In a continuously variable transmission, a drive pulley comprising a fixed pulley half and a movable pulley half that can move forward and backward with respect to each of the drive shaft and the driven shaft is provided, and an endless transmission is provided between the drive pulley on the drive shaft and the driven shaft. A continuously variable transmission that suspends a V-belt and moves and adjusts the movable pulley halves on the drive shaft and the driven shaft to transmit the rotation of the drive shaft and the rotation of the driven shaft continuously to the driven shaft. Exists. In such a transmission, the driven pulley and the driven shaft are generally connected via a centrifugal clutch.

When the rotational speed of the driven pulley exceeds a predetermined value, the centrifugal clutch has a centrifugal weight pivotally supported on each support pin of the clutch plate with the support pin as a center of rotation on the radially outer peripheral side. It swings and its free end expands outward. As a result, the lining bonded to the centrifugal weight comes into contact with and connects to the inner peripheral surface of the annular side surface of the clutch outer, and the rotation is transmitted to the driven shaft fixed to the clutch outer. The number of centrifugal weights used in this centrifugal clutch is generally three or more as disclosed in Patent Document 1.
JP 2002-39227 A

  In the centrifugal clutch, the number of centrifugal weights of the centrifugal clutch connected to the driven pulley is 3 or more for the following reason. This is because in such a centrifugal clutch, when the number of centrifugal weights is two, the weight per centrifugal weight becomes heavy and large vibrations are generated. In general, the centrifugal weight c of the centrifugal clutch is attached and fixed to a support shaft b of the clutch body a by a retaining ring (circlip) d so as to be replaceable (see FIG. 8).

  Since the centrifugal weight is fixed by a retaining ring through the side plate, a gap is generated between the centrifugal weight and the side plate attached to the support shaft, and the gap causes a backlash at the support portion of the centrifugal weight. May occur. This backlash may cause the centrifugal weight, which is heavy per unit, to be in a swinging state when the centrifugal clutch is operated. Furthermore, since the two centrifugal weights mentioned above come into contact with the clutch housing disposed on the outer periphery of the centrifugal weight while swinging, the contact surface is not uniform and the contact portion is strong. Due to the distortion, the difference in force (weight) between the abutting part and the non-abutting part becomes large, resulting in an unbalanced state and a large vibration source.

  For this reason, it is extremely difficult to reduce the number of centrifugal weights to 2 because various disadvantages occur. Therefore, usually three or more are set. If the number of centrifugal weights is 3 or more, the weight per piece can be reduced, the force applied to the clutch housing is distributed from 2 to 3 places, distortion can be reduced, and vibrations can be reduced accordingly. Although it is good in function, there is a problem that the mechanism is complicated, adjustment is difficult, and cost is higher than that in the case where the number of centrifugal weights is two. The problem (technical problem or object) to be solved by the present invention is that, in three or less centrifugal weights, the vibration generated by the external force applied to each centrifugal weight is minimized, and the structure is extremely simple. It is to realize something.

  Accordingly, the inventor has intensively and intensively studied to solve the above-described problems. As a result, the invention of claim 1 is applied to the outer peripheral portion of the substantially disc-shaped clutch plate via a support pin and no more than three centrifugal weights. In the centrifugal clutch in which the centrifugal weight is rotatably mounted and the centrifugal weight transmits the rotation to the clutch outer, it has a substantially disk shape with a shaft through hole formed in the center, and the number of the support pins mounted is equal to the outer periphery. A side plate having a plurality of through holes is provided, the side plate is disposed on the centrifugal weight so as to cover the centrifugal weight, and the support pin includes a large-diameter shaft portion and a tip. A step surface is formed with the small-diameter shaft portion in which a recess for expanding and crimping is formed, and the through hole portion of the side plate is supported by the step surface and is inserted into the through hole. By the centrifugal clutch in which the side plate characterized by comprising fixed to the support pin at the caulking deformation by expansion of the small diameter shaft tip that is, the above-mentioned problems are eliminated.

  Next, the invention of claim 2 solves the above-mentioned problem by adopting a centrifugal clutch characterized in that the number of centrifugal weights is two in the description of claim 1.

  According to the first aspect of the present invention, three or less centrifugal weights are swingably attached to the outer peripheral portion of the substantially disc-shaped clutch plate via the support pin, and the tip end portion of the support pin penetrates. A side plate having a through hole is disposed on the centrifugal weight so as to cover the centrifugal weight.

  And since the front-end | tip of the said support pin is penetrated and fixed to the through-hole of a side plate, the said support pin is fixed to the clutch plate at the one end side of an axial direction, and the other end side is fixed to the side plate. In addition, since the support pins that support three or less centrifugal weights are supported by the same clutch plate and side plate, and the support pins and the side plate are in a fixed state, all the support pins are in the axial direction. Both ends of are substantially supported.

  Therefore, even if a strong external force is applied to the centrifugal weight and vibration is generated, the support pins that support the centrifugal weight are not single-supported, but are supported at both ends, and therefore sufficiently withstand the vibration of the centrifugal weight. At the same time, it can also serve to suppress vibrations that are about to occur in the centrifugal weight.

  In particular, the tip of the support pin inserted into the through hole of the side plate is fixed to the side plate by caulking deformation, so that the fixed state is extremely strong, and as a result, durability and long life can be achieved. .

  Next, in the invention of claim 2, since the number of centrifugal weights is two, the number of centrifugal weights of the centrifugal clutch can be minimized, and only one side plate is used. Therefore, it can be provided at a low price. Furthermore, by setting the number of centrifugal weights to 2, the number of centrifugal rollers for changing the pulley groove width in the automatically variable type driving pulley (primary pulley) whose pulley groove width changes according to the number of rotations is set. 3 can be realized, thereby realizing a minimum combination in which the ratio between the number of centrifugal rollers and the number of components of the centrifugal weight is a non-integer, and the vibration of the entire automatic transmission can be suppressed. Become. In addition, an inexpensive device can be provided. And a function and quality can be improved, and also merchantability and durability can be improved.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of a centrifugal clutch connected to a continuously variable transmission according to the present invention and its main part. As shown in FIG. 1 (A), the centrifugal clutch of the present invention shares the same shaft mechanism and is used with continuously variable transmissions arranged adjacent to each other. It serves to interrupt the driving force via the continuously variable transmission. The centrifugal clutch is mainly composed of a clutch outer 1, a clutch plate 2, a centrifugal weight 5, and the like. The device connected to the centrifugal clutch is a driven side transmission pulley 10 (see FIG. 1A), which is of a type in which the pulley groove width is variable. The driven side transmission pulley 10 is rotationally transmitted through a belt from a driving side transmission pulley (not shown). The rotation of the driven transmission pulley 10 transmitted from the driving transmission pulley via the belt is connected or disconnected by the centrifugal clutch of the present invention.

As shown in FIG. 1A, the clutch outer 1 has a substantially cup shape, and a disc-shaped side portion 1b is formed around the boss portion 1a, and the outer peripheral edge of the disc-shaped side portion 1b. A cylindrical side portion 1c is formed on the side. Cylindrical side 1c has a cylindrical shape, the inner peripheral wall surface 1c ₁ thereof, in which lining is attached to the centrifugal weights 5 which swings are in contact.

  As shown in FIGS. 1A, 1B, 2A, and 3A, the clutch plate 2 has a driven transmission pulley 10 (variable pulley) at the center of the main plate portion 2a. A fixing hole 2b in which the shaft end of the boss 10a on the fixed pulley side is mounted is formed. The fixing hole 2b has an elliptical shape with linear edges formed on both sides in the width direction, and can be firmly fixed to the shaft end of the boss 10a in the rotational direction. Yes. The clutch plate 2 is formed as a flat face plate.

  On the surface side of the clutch plate 2, the support pins 3 are implanted. A through hole 2c is drilled for planting the support pin 3. The shaft end of the support pin 3 is inserted into the through hole, and press-fitting or crimping is performed (see FIG. 1C). Next, the centrifugal weight 5 is formed from a uniform and homogeneous metal alloy, and the overall shape thereof is formed in a substantially arc shape or crescent shape as shown in FIG.

  On the one end side of the centrifugal weight 5 in the longitudinal direction, a swinging center portion 5P is formed. The swing center portion 5P is formed as a through hole, the support pin 3 is inserted, the swing center portion 5P becomes the swing center through the support pin 3, and the centrifugal weight 5 is the clutch plate. Oscillate on 2 Since the support pin 3 is implanted at the end of the clutch plate 2 in the diametrical direction, the swinging central portion 5P of the centrifugal weight 5 is also positioned closer to the end of the clutch plate 2 in the diametrical direction, that is, the outer peripheral edge. is doing.

  The substantially circular arc-shaped centrifugal weight 5 has an outer peripheral surface 5a and an inner peripheral surface 5b. The outer peripheral surface 5a and the inner peripheral surface 5b are each formed as an arcuate surface. The outer peripheral surface 5 a of the centrifugal weight 5 is the outer peripheral side and faces the outer side of the clutch plate 2, and the inner peripheral surface 5 b is the inner peripheral side and faces the center side of the clutch plate 2.

As shown in FIG. 1 (A), the clutch plate 2 is rotated by the rotation of the driven transmission pulley 10 (variable pulley) through the boss 10a and spreads in the outer circumferential direction by the centrifugal force of the rotation. mounted centrifugal weights 5,5, and supports the centrifugal weights 5,5 in contact with the inner circumferential wall surface 1c ₁ of cylindrical side wall 1c of the clutch outer 1, is intended for transmitting rotation to the clutch outer 1. A lining is attached to the outer peripheral surface 5 a of the centrifugal weight 5.

  The side plate 6 has a substantially disc shape with a shaft through hole 6b formed at the center. A through hole 6a is formed near the outer periphery. The number of the through holes 6a is the same as the number of the support pins 3 attached. Accordingly, in the type in which two centrifugal weights 5 are mounted, two through holes 6a are formed (see FIG. 2). In the type in which three centrifugal weights 5 are mounted, three through holes 6a are formed (see FIG. 6).

  The side plate 6 is fixed to the support pin 3. There are two means for the fixing by caulking and press-fitting. First, in the fixing means by caulking, the support pin 3 is formed with a large-diameter shaft portion 3a and a small-diameter shaft portion 3b [see FIG. 4 (A)]. Further, a hole-like depression 3c is formed at the tip of the small diameter shaft portion 3b along the axial direction. The small diameter shaft portion 3 b has a diameter that can be inserted into the through hole 6 a of the side plate 6. The diameter of the large diameter shaft portion 3a is larger than the inner diameter of the through hole 6a. Therefore, the side plate 6 is supported by the tip of the large-diameter shaft portion 3a where the through-hole 6a is a step surface 3d with the small-diameter shaft portion 3b, and the small-diameter shaft portion 3b penetrates the through-hole 6a. (See FIG. 4B). By determining the position of the step surface 3d formed at the step portion between the large diameter shaft portion 3a and the small diameter shaft portion 3b, the length of the large diameter shaft portion 3a is the length of the swinging central portion 5P of the centrifugal weight 5. The side plate 6 is attached and fixed to the support pin 3 so as to have an appropriate gap with respect to the centrifugal weight 5.

  Then, with the small diameter shaft portion 3b penetrating the through hole 6a, the tip of the small diameter shaft portion 3b is widened using the tool 11 or the like in the recess 3c, and the small diameter shaft portion 3b of the support pin 3 is axially moved. And is deformed by caulking [see FIG. 4C]. That is, the small diameter shaft portion 3b of the support pin 3 is pushed in the axial direction to expand the small diameter shaft portion 3b in the axial diameter direction, and the side plate 6 is moved to the tip of the large diameter shaft portion 3a of the support pin 3 (small diameter shaft). The tip of the small-diameter shaft portion 3b swells in the radial direction by caulking deformation and becomes larger than the through hole 6a of the side plate 6, and is fixed to the support pin 3 and the side. The plate 6 is firmly fixed. Further, such a fixed structure reduces the number of components and simplifies the structure.

  Thus, by forming the depression 3c at the tip of the small diameter shaft portion 3b of the support pin 3, the small diameter shaft portion 3b is pressed in the axial direction at the through hole 6a portion of the side plate 6 and is also in the diameter direction. Since it expands, the support pin 3 and the side plate 6 can be firmly held in both the axial direction and the radial direction. The recess 3c is formed in a small diameter shaft portion 3b so as to be narrowed in the axial direction from the opening at the shaft end.

  In addition, the recess 3c may be a conical and narrow hole. The centrifugal weight 5 is swung by the side plate 6 that supports the tip of the support pin 3 on the other end side between the shafts of the two support pins 3 of the clutch plate 2 to which the centrifugal weight 5 is mounted by such caulking deformation. The number of the centrifugal weights 5 can be reduced to 2 by using the support pins 3 that support the operation with the plates provided on both sides of the support pins 3 and fixing them. Made it possible to do. Next, in the case of using press-fitting means, the recess 3c is not formed [see FIG. 5 (B)].

Further, the diameter of the small diameter shaft portion 3b is formed slightly larger than the inner diameter of the through hole 6a of the side plate 6, and the small diameter shaft portion 3b has a tight fit configuration with respect to the through hole 6a [FIG. (See (A)). In addition, there is another embodiment that performs caulking deformation according to another embodiment in which the tip end portion of the small-diameter shaft portion 3b of the support pin 3 is enlarged in the radial direction. In this embodiment, the recess 3c is not formed on the small diameter shaft portion 3b, by forming a recess in the linear groove 3c ₁ and point-like portion 3c _2, it is intended to crimping deformation. As shown in FIG. 7A, the linear groove portion 3c ₁ is an arc-shaped groove and is formed in two. The point-like portion 3c _2, as shown in FIG. 7 (B), a plurality (about 3) are formed. In this way, the support pin 3 and the side plate 6 can be fixed firmly by press-fitting, and the support pin 3 and the side plate 6 can be fixed more firmly by being secured by crimping deformation. .

(A) is a longitudinal side view of the centrifugal clutch of the present invention and a driven transmission pulley to which the centrifugal clutch is connected, (B) is a front view of the centrifugal clutch, and (C) is an enlarged view of a portion of (A). (A) is a front view in which two clutch weights are mounted on a clutch plate, and (B) is a front view of a side plate. (A) is a longitudinal side view of the clutch weight mounted on the clutch plate, and (B) is a longitudinal side view of the side plate. (A) thru | or (C) are process drawings of caulking. (A), (B) is a process drawing of press-fitting. (A) is a front view in which three clutch weights are attached to a clutch plate, and (B) is a front view of a side plate. (A) is an embodiment in which crimping deformation is formed by forming linear grooves in the small-diameter shaft portion, and (B) is an embodiment in which crimping deformation is formed by forming a plurality of dots in the small-diameter shaft portion. It is. It is a schematic diagram which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Clutch outer, 2 ... Clutch plate, 3 ... Support pin, 5 ... Centrifugal weight,
6a ... through hole, 6 ... side plate.

Claims (2)

In a centrifugal clutch in which three or less centrifugal weights are swingably attached to the outer peripheral portion of a substantially disc-shaped clutch plate via a support pin, and the centrifugal weight transmits rotation to the clutch outer. Is formed in a substantially disk shape, and a side plate is provided in the vicinity of the outer periphery with the same number of through-holes as the number of support pins mounted, and the side plate is configured to cover the centrifugal weight. The support pin is disposed on a centrifugal weight, and the support pin has a step surface formed between a large-diameter shaft portion and a small-diameter shaft portion in which a recess is formed so that the tip is expanded and crimped. through hole portion of the side plate is supported by a surface, the side plate at caulking deformation by expansion of the small diameter shaft tip inserted through the through hole is solid to the support pin Centrifugal clutch, characterized in that formed by.   2. The centrifugal clutch according to claim 1, wherein the number of centrifugal weights is two.

Images