JPH0620927U - Centrifugal clutch - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the manufacturing process and cost. [Structure] A plurality of clutch shoes 8 arranged in a circle around the clutch shaft 5 so as to rotate integrally with each other are molded from a rubber-based friction material including a lining portion, and one or more are formed on a peripheral surface of the clutch shoe 8. A plurality of recessed grooves 10 are provided, and an annular elastic body 11 that biases the clutch shoe 8 toward the clutch shaft 5 is inserted into the recessed grooves 10, and
The conventional lining bonding step and the post-processing step for forming the concave groove are unnecessary, and the elastic force of the elastic body 11 can be small.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a centrifugal clutch used as a power transmission means for construction machines, vehicles, work machines and the like.

[0002]

[Prior art]

 Centrifugal clutches utilize the centrifugal force of a clutch shoe that rotates with a rotating shaft connected to a power source such as a motor or engine, and accelerate the rotation of the power source to operate the clutch and transmit power. As an automatic mechanism that cuts the clutch by decelerating the rotation of the power source, it is a power transmission means that transmits the rotational torque from the power source to the load side, and is widely used in construction machines, vehicles, work machines, etc. There is.

FIG. 7 is a diagram showing an example of a conventional centrifugal clutch. FIG. 7 (a) shows a clutch drum connected to a load by a belt or the like, and FIG. 7 (b) is connected to a power source. The clutch body is shown.

As shown in FIG. 7 (b), the clutch main body 21 has a plurality of metallic clutch shoes 23 having fan-shaped side surfaces arranged around a clutch shaft 22 connected to a power source. However, FIG. 7B shows an example in which a total of four clutch shoes 23 are used. A lining 24 made of resin mold is attached to the peripheral surface of each clutch shoe 23.

Further, each clutch shoe 23 is formed with a groove 25 on both sides thereof, and when the clutch shoe 23 is arranged around the clutch shaft 22, the grooves 25 on both sides of all clutch shoes 23 are formed. An annular coil spring 26 is housed in the two circumferentially formed concave groove portions by connecting both ends thereof.

When the coil spring 26 is not used, a hook spring is used to pull in the radial direction.

The clutch body 21 thus assembled is housed inside the inner peripheral portion (not shown) of the clutch drum 27 of FIG. 7A, and the clutch shaft 22 serves as a power source such as a motor and an engine. On the other hand, the groove 28 of the clutch drum 27 is connected to the load by the belt.

As the rotational speed of the power source increases, the centrifugal force generated by the rotation of the clutch shoe 23 causes the clutch shoe 23 to overcome the elastic force of the coil spring 26 and move in the radial direction, thereby lining the clutch shoe 23. The frictional contact between the inner peripheral portion of the clutch drum 27 and the inner peripheral portion of the clutch drum 27 causes the frictional force between the lining 24 and the inner peripheral portion of the clutch drum 27 to transmit the driving force of the clutch shaft 22 to the clutch drum 27. The rotational torque from the power source is transmitted to the load.

[0009]

[Problems to be solved by the device]

 As described above, in the conventional centrifugal clutch, the clutch shoe 23 is made of a material having a large specific gravity, such as metal, for the purpose of giving the clutch shoe 23 an appropriate mass so that the clutch shoe 23 receives a certain centrifugal force. A lining 24 made of a material having a large coefficient of friction, such as a resin mold, is adhered to the peripheral surface of the rim 24 to obtain friction.

In addition, in order to smoothly move the clutch shoe 23 in the radial direction according to the number of rotations, the groove 25 of each clutch shoe 23 into which the annular coil spring 26 is inserted has the mass of the clutch shoe 23. Since it is made of a large metal, it is usually formed on both sides of the clutch shoe 23, but this step requires post-processing.

As described above, the step of adhering the lining 24 and the step of forming the concave groove 25 are required, and there are many manufacturing steps.

An object of the present invention is to provide a low-cost centrifugal clutch that enables reduction of the manufacturing process.

[0013]

[Means for Solving the Problems]

 According to the present invention, a plurality of clutch shoes, which are circularly arranged so as to integrally rotate around a clutch shaft, are molded by a rubber-based friction material including a lining portion, and one or more clutch shoes are formed on a peripheral surface of the clutch shoe. Is provided with an annular elastic body for urging the clutch shoe in the direction of the clutch shaft.

[0014]

[Action]

 In the present invention, as the clutch shoe rotates with the clutch shaft connected to the power source, centrifugal force moves radially against the biasing force of the elastic body, causing frictional contact with the inner circumference of the clutch drum to rotate. Transmits torque.

[0015]

【Example】

 FIG. 1 is a view showing a centrifugal clutch according to an embodiment of the present invention. The upper half of FIG. 1 is shown as a cross-sectional view of the centrifugal clutch taken along the vertical center line when viewed from the direction of the rotation axis.

The centrifugal clutch 1 is roughly classified into a clutch drum 2 on the driven side that is connected to a load by a belt and the like, and a clutch body 3 on the driving side that is connected to a power source by a rotating shaft such as a motor or an engine. Composed of.

The clutch drum 2 is formed of a solid material such as metal, and a groove portion 4 into which a belt for transmitting power to a load is fitted is provided on the outer peripheral portion of the clutch drum 2. Further, the inner peripheral part thereof is formed into a hollow shape to accommodate the clutch body 3.

The clutch drum 2 and the clutch body 3 are rotatably connected to each other by a ball bearing 6, and the ball bearing 6 is attached to the clutch shaft 5 by a stop ring 7.

FIG. 2 is a front view of the clutch body 3. The clutch main body 3 includes a clutch shaft 8 made of a solid material such as metal and a plurality of (6 in this example) clutch shoes 8 made of rubber-based friction material, and 6 fins 9 (clutch system) provided on the clutch shaft 5. The same number as that of the coil 8), and the annular coil spring 11 (corresponding to the elastic body of the present invention) in the groove 10 (see FIGS. 1 and 5) provided on the peripheral surface of each clutch shoe 8. ) Are stored, and the side covers 12 (see FIG. 6) assemble these so that they are held so as not to move in the rotation axis direction.

Hereinafter, each component constituting the clutch body 3 and an assembling method will be described.

3 and 4 are views showing the clutch shaft 5. FIG. 3 (a) is a front view, FIG. 3 (b) is a side view, and FIG. 4 (a) is A in FIG. 3 (a). FIG. 4B is a cross-sectional view taken along line A-A 'of FIG.

As shown in FIG. 3B, the clutch shaft 5 is roughly divided into a thin shaft portion 5a, a large shaft portion 5b, and a clutch shoe insertion portion 5c. As shown in FIG. 3A, the clutch shoe insertion portion 5c is provided with six fins 9 into which the clutch shoe 8 is inserted. As shown in FIG. 4B, the fin 9 is formed such that its shape becomes slightly thinner toward the tip. Further, two of the six fins 9 are provided with protrusions 13 for fitting the side cover 12 at their tip ends. Further, the clutch shaft 5 is formed with a shaft hole 14 at the center thereof into which a rotary shaft for connecting to a power source such as a motor or an engine is inserted.

FIG. 5 is an external view of the clutch shoe 8, FIG. 5 (a) is a front view, FIG. 5 (b) is a side view, and FIG. 5 (c) is a top view.

The clutch shoe 8 is made of a rubber-based friction material, including the peripheral lining portion. As shown in FIG. 5A, the side surface of the clutch shoe 8 is formed into a fan shape, and six clutch shoes 8 are inserted between the six fins 9 in this embodiment. The sector angle of the clutch shoe 8 is formed to be 60 degrees.

As shown in FIGS. 5B and 5C, a coil spring 11 for urging the clutch shoe 8 toward the center of the clutch shaft 5 is inserted in the peripheral surface of the clutch shoe 8. The concave groove 10 is formed. The clutch shoe 8 can be seen from the fact that the left and right side surfaces and the bottom surface in FIG. 5A are represented by double lines in accordance with the shape of the fins 9 of the clutch shoe insertion portion 5c of the clutch shaft 5. Thus, it is formed with a slight taper.

The six clutch shoes 8 are inserted between the six fins 9 of the clutch shoe insertion portion 5c of the clutch shaft 5, and the coil springs 11 are inserted into the concave grooves 10 on the peripheral surface of each clutch shoe 8. Then, the clutch shoes 8 are arranged around the clutch shaft 5.

FIG. 6 is an external view of the side cover 12, FIG. 6A is a front view, and FIG. 6B is a side view. The side cover 12 is a cover for preventing each clutch shoe 8 from moving in the rotation axis direction, and the eaves 16 at the central portion is inserted into the thick shaft portion 5b of the clutch shaft 5 and the two holes 15 are provided. The projection 13 of the clutch shaft 5 is inserted into the clutch shaft 5 and is firmly fitted into the clutch shaft 5 so as to be fixed by caulking.

Regarding the assembly of the clutch drum 2 and the clutch body 3, first, the ball bearing 6 is press-fitted into the clutch drum 2 and the circlip 17 is inserted into the groove 18 (see FIG. 1) of the clutch drum 2. Thus, the ball bearing 6 is fixed to the clutch drum 2. Next, the clutch shaft 5 of the clutch body 3 is press-fitted into the ball bearing 6 of the clutch drum 2, and the stop ring 7 for preventing the clutch body 3 from coming off the clutch drum 2 is provided with the groove 19 (FIG. 1). , 3)). Thus, the assembly of the centrifugal clutch 1 is completed.

In the illustrated embodiment, the clutch shoe 8 that transmits power by centrifugal force associated with rotation is molded from a rubber-based friction material including the lining portion, and the coil spring 11 is inserted in the forming process of the clutch shoe 8. Compared to the case where the lining (24 in FIG. 7) is adhered onto the conventional metal clutch shoe (23 in FIG. 7) by simultaneously molding the recessed groove 10 to be manufactured, The process can be greatly simplified and the cost can be reduced. Further, since the clutch shoe 8 is not made of metal or the like having a large mass but is made of a rubber-based friction material which is lighter in weight, a coil spring 11 for disposing them around the clutch shaft 5 is provided. However, since it is possible to use one with a weaker elastic force or one with a smaller number, usually only one coil spring 11 is required, and it is also possible to substitute this with a rubber ring. It is possible to reduce the cost and the cost accordingly.

[0030]

[Effect of device]

 As described above, according to the present invention, a plurality of clutch shoes, which are circularly arranged so as to rotate integrally around the clutch shaft, are molded by a rubber-based friction material, including the lining portion, and the clutch shoe is formed. One or more recessed grooves are provided on the peripheral surface of the shoe, and an annular elastic body that biases the clutch shoe toward the clutch shaft is inserted into the recessed grooves. Since the post-processing step for forming is unnecessary and the elastic force of the elastic body is small, it is possible to reduce the number of manufacturing steps and accordingly reduce the cost. Further, by using a rubber-based friction material having a large frictional force, it is possible to provide the same performance as the conventional product even if the clutch shoe is relatively lightweight. In addition, the impact of the driving force on the clutch drum and clutch shaft is mitigated by the clutch shoe made of elastic rubber-based friction material, which makes it possible to prevent metal parts such as the clutch drum and clutch shaft from being consumed. . As a result, it is possible to perform casting by molding a light alloy or the like integrally with the clutch shaft and the fins of the clutch shoe supporting portion, and it is possible to further reduce the cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a centrifugal clutch according to an embodiment of the present invention.

FIG. 2 is a front view of a clutch body according to an embodiment of the present invention.

FIG. 3 is an external view of a clutch shaft according to an embodiment of the present invention.

FIG. 4 is a view showing a structure of a clutch shaft according to an embodiment of the present invention.

FIG. 5 is an external view of a clutch shoe according to an embodiment of the present invention.

FIG. 6 is an external view of a side cover according to an embodiment of the present invention.

FIG. 7 is a view showing a conventional centrifugal clutch.

[Explanation of symbols]

 1 Centrifugal Clutch 2 Clutch Drum 3 Clutch Main Body 4 Groove 5 Clutch Shaft 6 Ball Bearing 7 Stop Ring 8 Clutch Shoe 9 Fin 10 Groove 11 Coil Spring (Elastic Body) 12 Side Cover 13 Protrusion 14 Shaft Hole 15 Hole 16 Eave 17 Circlip 18 grooves 19 grooves

Claims (1)

[Scope of utility model registration request] 1. A plurality of clutch shoes are circularly arranged around the clutch shaft so as to rotate integrally, and an annular elastic body urges the clutch shoe in the direction of the clutch shaft. In a centrifugal clutch in which the lining portion of the peripheral edge of the clutch shoe is brought into frictional contact with the clutch drum against the urging force of the elastic body by the centrifugal force associated with the rotation, the clutch shoe including the lining portion is A centrifugal clutch, characterized in that it is made of a friction material and has one or a plurality of recessed grooves formed on the peripheral surface of the clutch shoe, and an annular elastic body is inserted into the recessed grooves.