JP3010138B2 - Centrifugal clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal clutch.

[0002]

2. Description of the Related Art A centrifugal clutch is capable of rotating integrally with a driving base plate provided with a clutch shoe that expands and returns in a radial direction with respect to a rotating board that can rotate integrally with an input shaft, and an output shaft. And a driven side drum surrounding all clutch shoes.

[0003] In the driving side panel, the clutch shoe
And about four of them are provided, each of which has a tension spring mounted between opposite sides thereof, thereby setting a centrifugal force (that is, an input shaft rotation speed at which the clutch is connected) required to spread in the radial direction. Yes (57-77733)
Gazette, Japanese Utility Model Application Laid-open No. Sho 59-113521, Japanese Utility Model Application Laid-open No. Sho 62
194219).

[0004]

In this type of centrifugal clutch, when changing the number of rotations to which the clutch is connected, the position (tensile length) of the tension spring engaged with the clutch shoe is changed, or the tension spring or the clutch is changed. The shoe was replaced by one with a different spring force or shoe load. These operations involve removing the tension spring from the clutch shoe. Therefore, for this purpose, it is necessary to extend the tension spring once against its spring force, which has been an extremely difficult and cumbersome operation.

Furthermore, in order to make this operation easier, it is necessary to increase the diameter of the rotating board to some extent, which has been a bottleneck in downsizing the clutch. In addition, a boss used for connection with the input shaft is provided at the center of the rotating board, but this boss is not integrated with the rotating board but is connected by a shaft fitting structure or the like. Normal. On the other hand, the tension spring is provided so as to connect the opposite sides of the clutch shoe as described above, and passes near the center of the rotating board. Accordingly, the rotating board needs to have a large axial dimension or radial dimension in order to prevent interference between the coupling portion of the boss portion and the tension spring. This is also inconvenient for downsizing the clutch.

The present invention has been made in view of the above circumstances. First, it is possible to easily change the number of revolutions to which the clutch is connected, and secondly, it is possible to reduce the size of the clutch. It is an object of the present invention to provide a centrifugal clutch as described above.

[0007]

According to the present invention, the following technical measures are taken to achieve the above object. That is, according to the present invention, a plurality of clutch shoes are provided so as to be movable in the radial direction with respect to the rotating board, and a coaxial rotation with the driving side board surrounding all the clutch shoes. In the centrifugal clutch having a driven drum that is freely movable, the driving-side plate body is configured such that each clutch shoe is swingable by a swing fulcrum provided near one end in a circumferential direction, and each clutch shoe is The shoe is provided with a movable piece that can be adjusted in the circumferential direction on the side that extends long from the swing fulcrum, and moves the clutch shoe adjacent to the side that extends shortly from the swing fulcrum on the same side. A tension spring connected to the piece is provided, and each moving piece is provided with a spring force adjusting means that enables a position change of the moving piece without loosening the tension force of the tension spring. And

[0008] In the prime mover body of the centrifugal clutch, a moving piece is provided for each clutch shoe, the position of which is adjustable in the circumferential direction. One end of the spring is engaged. The position of the moving piece can be adjusted by a spring force adjusting means. Since this spring force adjusting means can move the moving piece without loosening the tension force of the tension spring, there is no need to remove the tension spring from the clutch shoe at all.

The tension spring is provided not between the opposite sides of the clutch shoes but between adjacent ones of the clutch shoes, that is, in a state extending along the circumferential direction. For this reason, the center of the rotating substrate becomes an open space, and the portion connecting the boss portion to the rotating substrate does not cause interference with a tension spring or the like. Therefore, the diameter of the rotating substrate can be reduced.

[0010] Specific examples of the spring force adjusting means include a screw feed mechanism (claim 2), a cam mechanism (claim 3), and a structure using a pliers tool (claim 4).

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a centrifugal clutch 1 according to the present invention. This centrifugal clutch 1 is used in an automatic type motorcycle or the like, and its entire configuration is a driving side provided via a flywheel 4 or the like to an input shaft 3 on the engine 2 side as shown in FIG. It has a disk 5 and a driven drum 7 provided on an output shaft 6 which is coaxial with the input shaft 3 and can transmit rotational drive to driving wheels (not shown).

A plurality of driving base plates 5 (three in the illustrated example) are movable relative to the rotating substrate 10 in the radial direction.
The driven-side drum 7 surrounds all the clutch shoes 11 of the driving-side panel body 5 and circumscribes when they spread radially outward. These are basically the same as in the prior art.

Each clutch shoe 11 of the driving side panel 5 is
It has a shoe main body 14 formed in a partial arc piece shape, and a lining 15 fixed to the side surface of the arc. The clutch shoe 11 is swingably held on the rotating board 10 by a swing fulcrum portion 18 (see a pin through hole 18a of the shoe body 14) provided near one end in the circumferential direction (longitudinal direction). Therefore, this clutch shoe 11
The longer the side extending from the fulcrum 18 is, the more the rotating substrate 10
Spreads radially outward or returns radially inward.

The clutch shoes 11 are connected to each other by a tension spring 20. The tension spring 20 urges each clutch shoe 11 in a state of being pulled radially inward of the rotating board 10. One end of the tension spring 20 is hooked on an engagement hole 21 provided on a side extending short from the swing fulcrum 18. The other end of the tension spring 20 is connected to the swing fulcrum 1.
With respect to the moving piece 23 provided on the side extending from
It is hooked on the engagement hole 24 on one end side.

The moving piece 23 is fitted in a concave portion 25 which is formed in the clutch shoe 11 so as to be curved along the circumferential direction. Then, a fixing bolt 27 is inserted into a long hole 26 provided through the thickness direction of the moving piece 23, and the fixing bolt 27 is screwed into a bolt hole 28 provided at the bottom of the concave portion 25, whereby the clutch is engaged. The shoe 11 is fixed to the shoe 11. Therefore, if the fixing bolt 27 is loosened, the moving piece 23
Can be adjusted along.

The back surface of the moving piece 23 and the bottom surface of the concave portion 25 are formed with a notch, respectively, so that fine (increment-like) position adjustment can be performed by engagement of these. Further, since the jagged teeth are engaged, even if the fixing bolt 27 is loosened slightly, the moving piece 2
There is no possibility that the position 3 is displaced by being pulled toward the tension spring 20 side.

The position of the moving piece 23 can be changed by the spring force adjusting means 30. The spring force adjusting means 30 is provided in the
A feed screw 32 inserted into the concave portion 25 from the outside with the peripheral wall of 5 being interposed therebetween;
And a nut member 33 provided in a protruding state in the back surface direction of the moving piece 23.

The feed screw 32 is fitted with a retaining ring 35 and the like inside the recess 25 so that the clutch shoe 11
, And cannot move in the axial direction. Further, a portion protruding outside the concave portion 25 is formed in a hexagonal rod shape so that a tool such as a small spanner can be engaged. The nut member 33 is rotatable about the projecting axis with respect to the moving piece 23.

In the clutch shoe 11, a second concave portion 36 for fitting the nut member 33 of the moving piece 23 is formed on the bottom surface of the concave portion 25. The hole 37 through which the feed screw 32 penetrates the peripheral wall of the concave portion 25 is preferably formed in a horizontally long hole shape so that the feed screw 32 can be slightly moved in the horizontal direction according to the rotation of the nut member 33. It is.

With such a structure, the fixing bolt 27 of the moving piece 23 is loosened, and the spring force adjusting means 3 is set.
When the feed screw 32 is rotated, the moving piece 23 is
5 can be moved in a desired direction by a desired amount.
Further, it is easy to make the moving amounts of all the moving pieces 23 equal. Therefore, this makes it possible to change the tensile force of the tension spring 20, that is, to change the rotation speed of the input shaft 3 at the time when the clutch is engaged. In this case, it is needless to say that even if the moving piece 23 is moved in the direction in which the tension force of the tension spring 20 is increased, it is not necessary to remove the tension spring 20 (that is, loosen the tension force of the tension spring 20).

FIG. 6 shows a spring force adjusting means 30 used in a second embodiment of the centrifugal clutch 1 according to the present invention. Of the moving piece 23 can be adjusted. That is, the moving piece 23 has a long hole 40 long in the width direction (radial direction of the rotating substrate 10).
3 through the thickness direction. On the other hand, the clutch shoe 11 has an eccentric operation shaft 41 in which the eccentric portion is fitted in the elongated hole 40 in an inscribed state,
Is held rotatably about the axis 42 with respect to the bottom surface of the.

The eccentric operation shaft 41 is provided separately from the fixing bolt 27 for positioning and fixing the moving piece 23 with respect to the recess 25. Therefore, in the second embodiment, the eccentric operation shaft 4 is set with the fixing bolt 27 loosened.
The movable piece 23 can be moved by rotating the movable piece 1.

FIG. 7 shows a spring force adjusting means 30 used in a third embodiment of the centrifugal clutch 1 according to the present invention. In the third embodiment, a pliers tool (shown in FIG. 7) separately attached and prepared. (Abbreviation), the position of the moving piece 23 in the recess 25 can be adjusted. That is, on the clutch shoe 11 side, the moving piece 23 is
The insertion hole 45, which can pierce the tip of the fork of the pliers tool, into the appropriate position on the other side to be moved against the spring force of the pliers and the appropriate position on the moving piece 23 side near this portion.
46 are formed.

Therefore, in the third embodiment, with the fixing bolt 27 loosened, the tip of the pliers tool is pierced into the insertion holes 45 and 46, and the pliers tool is opened or closed to move the moving piece. 23 can be moved. Incidentally, the present invention is not limited to the above embodiment. For example, the number, shape, and the like of the clutch shoes 11 can be changed as appropriate. Further, the centrifugal clutch 1 can be used for agricultural equipment such as a mower, in addition to a motorcycle.

[0025]

As is apparent from the above description, in the centrifugal clutch according to the present invention, a moving piece whose position can be adjusted in the circumferential direction is provided on the clutch shoe in the driving-side panel body. One end of a tension spring that pulls the clutch shoe radially inward is engaged. The position of the moving piece can be adjusted by a spring force adjusting means capable of moving the moving piece without loosening the tension force of the tension spring. Therefore, the tension spring is detached from the clutch shoe each time. Such troubles are not required.

Therefore, not only the initial spring force setting work performed when assembling the centrifugal clutch and when assembling the centrifugal clutch to the engine, but also when changing the rotational speed of the input shaft to which the clutch is connected (for example, when the , Or when tuning the engine) can be performed very simply and quickly.

Further, since the adjustment work is facilitated as described above, the diameter of the rotating substrate can be reduced, and the size of the clutch can be reduced. Furthermore, since the tension spring is provided not between the opposite sides of the clutch shoes but between adjacent ones of the clutch shoes, that is, along the circumferential direction, the center portion of the rotating board becomes an open space,
The portion connecting the boss portion to the rotating substrate does not cause interference with the tension spring or the like. Therefore, the diameter of the rotating board can be reduced, that is, the size of the clutch can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a centrifugal clutch according to the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is an exploded perspective view showing the clutch shoe of the first embodiment.

FIG. 4 is an enlarged sectional view taken along line BB of FIG. 1;

FIG. 5 is a schematic side sectional view showing the entire configuration of the centrifugal clutch.

FIG. 6 is an enlarged view of a main part showing a second embodiment of a centrifugal clutch according to the present invention.

FIG. 7 is an enlarged view of a main part showing a third embodiment of a centrifugal clutch according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 centrifugal clutch 5 driving-side board 7 driven-side drum 10 rotating board 11 clutch shoe 18 swing fulcrum 20 tension spring 23 moving piece 30 spring force adjusting means 32 feed screw 40 long hole 41 eccentric operation shaft 45 insertion hole 46 difference Hole

Claims (4)

(57) [Claims] A driving base plate (5) provided with a plurality of clutch shoes (11) movably in a radial direction with respect to a rotating substrate (10), and the driving unit surrounding all clutch shoes (11). In a centrifugal clutch having a side plate (5) and a driven drum (7) rotatable coaxially, in the driving side plate (5), each clutch shoe (11) is provided near one end in a circumferential direction. The swing fulcrum portion (18) is made swingable, and each clutch shoe (1
1) is provided with a movable piece (23) capable of adjusting the position in the circumferential direction on the side extending long from the swing fulcrum (18),
A tension spring (20) connected to the moving piece (23) of the adjacent clutch shoe (11) on the same side is provided on the side extending short from the swing fulcrum (18). ) Is provided with a spring force adjusting means (30) capable of changing the position of the moving piece (23) without loosening the tension force of the tension spring (20). 2. The spring force adjusting means (30) is screwed into the moving piece (23) in the direction of adjusting the position thereof.
2. A centrifugal clutch according to claim 1, further comprising a feed screw (32) which is rotatable with respect to the clutch shoe (11) and is axially immovable and held therethrough. 3. The spring force adjusting means (30) has an elongated hole (40) penetrating the moving piece (23) in the thickness direction, and an eccentric portion is fitted in the elongated hole (40) in an inscribed state. Eccentric operating shaft (4) rotatably held by the clutch shoe (11)
The centrifugal clutch according to claim 1, further comprising: (1). 4. The spring force adjusting means (30) can pierce the tip of the fork of the pliers tool with the pliers tool, the clutch shoe (11) and the moving piece (23), respectively. 2. The centrifugal clutch according to claim 1, further comprising insertion holes (45, 46) provided so as to form the clutch.