JPH0341157Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a centrifugal clutch, and more particularly, to a centrifugal clutch, and more particularly to a clutch boss connected to a drive shaft, and a clutch drum that is arranged concentrically with the clutch boss and can rotate independently of the clutch boss. , a plurality of clutch shoes attached to the clutch boss so as to be movable in the radial direction, and a spring that biases each clutch shoe inward in the radial direction, and when the rotational speed of the clutch boss increases during operation, the clutch shoes apply pressure to the clutch boss. It concerns a centrifugal clutch that moves radially outwardly against the action of a spring by centrifugal force, thereby frictionally engaging the clutch drum and transmitting rotational force to the clutch drum.

BACKGROUND ART Conventionally, the above-mentioned type of centrifugal clutch has been constructed such that the clutch boss is constituted by a large-diameter thick disc body, and a spring receiving frame is provided on the clutch boss, as shown in, for example, U.S. Pat. No. 3,367,465. A compression spring is disposed between the clutch and the clutch in a slot formed in alignment with the clutch to bias the clutch radially inwardly. Because of this configuration, the clutch boss is relatively heavier than the clutch shoe, and therefore the transmission efficiency is low.
The transmission power capacity was small, and the guide leg of the clutch shoe was short, which resulted in shortcomings such as low durability and high noise.

Problems to be solved by the invention Therefore, the invention aims to reduce the weight of the clutch boss relative to the clutch shoe as much as possible to reduce the weight of the clutch as a whole, improve transmission efficiency, increase the transmission power capacity, and increase the length of the guide leg of the clutch shoe. It is an object of the present invention to provide a centrifugal clutch that has increased durability, reduced noise, and can be made economically from relatively stable materials.

Means for Solving the Problems The present invention provides a clutch boss made of a flat plate member having a boss portion fixed to the drive shaft and a plurality of guide legs extending radially from the boss portion at equiangularly spaced positions. a recess is formed in each of the clutch shoes to receive a guide leg of the clutch boss within the recess and are mounted for radial movement along the respective guide leg, and a spring causes each guide leg of the clutch boss to move within the recess of the clutch The spring is disposed within the hollowed out longitudinal slot, and the spring abuts at its inner end a spring receiver which fits into the slot at the inner end of the clutch and at its outer end. It is characterized by a structure in which it is brought into contact with the outer end of the hole.

Accordingly, with the above structure of the present invention, sufficient centrifugal force can be maintained even if the center of gravity of the entire rotating body consisting of the clutch boss and the clutch shoe is located radially outward to reduce the weight of the entire rotating body. and moves the clutch radially along each relatively long guide leg.

Embodiments The present invention will be explained below based on embodiments shown in the drawings.

In this embodiment, the clutch boss 1 has a boss portion 2 and a shoe guide portion 3. The boss portion 2 forms a center hole 2', and a drive shaft (not shown) passes through this center hole 2' and is prevented from rotating by spline fitting or the like. The show guide part 3, which is made of SPC steel plate or the like, in this case integrally forms three guide legs 4 which are equiangularly spaced from each other and extend radially outwards. Furthermore, the show guide portion 3 has a spline hole 5 in the center.
The spline hole 5 is spline-engaged with the spline surface 6 on the outer periphery of the boss portion 2 to abut against the flange end 7 of the boss portion 2, and
The other end 8 is caulked to firmly fix the boss portion 2 and the shew guide portion 3 so that they cannot move relative to each other, thereby forming the clutch boss 1.

A clutch 9 made of a sintered metal or the like and having an overall T-shape is attached to each guide leg 4 so as to be movable in the radial direction, that is, in the longitudinal direction of the guide leg 4. A radially outer end 10 of each clutch shoe 9 is formed in a circular arc shape, and the outer end 10 is connected to the clutch shoe 9 as described below.
When it moves radially outward due to centrifugal force, it frictionally engages with the inner circumferential surface of the clutch drum 11. Further, each clutch shoe 9 has a recess 12 in its center that is open on one side, into which the guide leg 4 of the shoe guide portion 3 is received relatively movably.

On the other hand, each guide leg 4 forms a longitudinal slot 13 with wall portions 14 and 1 on either side of the slot 13.
5 extends into the recess 12 of the clutch 9. Furthermore, a compression coil spring 16 is arranged in the slot 13 of each guide leg 4, the spring 16 having a spring receiver which fits at its inner end into the slot 13 of the inner end of the clutch shoe 9. 19 and at its outer end rests on the outer end of the slot 13 of the guide leg 4, so that the clutch shoe 9 rests with its inner end on the inner end of the guide leg 4. It is biased toward the inner position with a predetermined strength. At this time, the outer end 10 of the clutch 9 is spaced radially inward from the inner peripheral surface of the clutch drum 11 and is in the clutch disengaged state.

The concave portion 12 of each clutch shoe 9 has a side plate 17 formed from SPC steel plate or the like to have the same shape as the clutch shoe 9.
The side plate 17 is fixed to the clutch shoe 9 by a pair of screws 18 passed through the side plate 17 and screwed from the opposite side of the clutch shoe 9.

During operation, the clutch boss 1 connected to the drive shaft
When the clutches 9 are rotated and their rotational speed increases to a predetermined value, each clutch 9 moves radially outward from its inner position due to centrifugal force against the biasing action of the spring 16, causing the outer end 10 to move. The clutch drum 11 is frictionally engaged with the inner circumferential surface of the clutch drum 11 to rotate the clutch drum 11 together with the clutch drum 11, thereby rotationally driving the sprocket and driven shaft connected to the clutch drum 11. When the rotational speed of the clutch boss 1 decreases and the centrifugal force applied to the clutch shoe 9 decreases, the clutch shoe 9 moves inward under the action of the spring 16, so that the frictional engagement between the clutch shoe 9 and the clutch drum 11 is released. The transmission of the rotational driving force to the clutch drum 11 and the driven shaft is then cut off.

In this embodiment, three clutches are provided, but any other number of clutches may be used as long as the centrifugal force is equally applied to each clutch.

Effects of the invention With the structure of the invention explained above, the invention achieves a structure that reduces the weight of the clutch boss to the maximum, realizing a lighter weight of the clutch, as well as maximizing the turning radius by effectively utilizing the weight of the clutch boss. As a result, the transmission efficiency is greatly improved and the transmission power capacity can be increased, and the sliding contact area between the clutch shoe and the guide leg is large, which greatly improves durability and generates less noise. Furthermore, even if the clutch drum disengages, the clutch shoe will not scatter, making it highly safe.
It has excellent effects such as simple structure and easy manufacture.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of a centrifugal clutch according to the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. 3 is a cross-sectional view taken from FIG. 1. 1...Clutch boss, 4...Guide leg, 9...
Clutch show, 11...Clutch drum, 12
... recess, 13 ... longitudinal slot, 16 ... compression coil spring.

Claims (1)

[Scope of utility model registration request] a clutch boss connected to a drive shaft; a clutch drum that is arranged concentrically with the clutch boss and can rotate independently of the clutch boss; and a plurality of clutch shoes that are movably attached to the clutch boss in a radial direction. a spring which biases the clutch shoe radially inward, and when the rotational speed of the clutch boss increases during operation, the clutch shoe moves radially outward against the action of the spring due to the centrifugal force applied thereto; In a centrifugal clutch configured to frictionally engage with a clutch drum and thereby transmit rotational force to the clutch drum, the clutch boss is separated from a boss portion fixed to the drive shaft at an equal angle between the boss portion and the clutch boss. a flat plate member having a plurality of guide legs extending in a radial direction from the clutch boss at a position where the clutch boss has a recess formed in each of the clutch shoes, and a guide leg of the clutch boss is received in the recess so as to extend along each guide leg; radially movably mounted, said spring being disposed within a recess of said clutch shoe in a longitudinal slot formed by hollowing out a respective guide leg of said clutch boss, and said spring being disposed at an inner end thereof in a recess of said clutch shoe. A centrifugal clutch, characterized in that it abuts a spring receptacle fitting in said slot at its inner end and abuts at its outer end against the outer end of said slot.