JPH0972352A - Clutch drum of centrifugal clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts by integrating a weight holder supporting a centrifugal weight at the end part capably of swinging in the radial direction with a drum main body. SOLUTION: A drum main body 1 is formed by pressing sheet metal, a part of a through window 7 close to the drum end wall part 1b is left unpressed, and by extruding the unpressed part 7a outward in the radial direction, the unpressed part 7a is formed into a weight holder 8.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a clutch drum of this type,
As shown in FIG. 4, in the peripheral wall portion c of the drum body b in which the spline a for engaging the clutch plate is formed, a long permeable window d is formed in the generatrix direction, and a portion near the end wall portion e of the drum body b. Is provided with a weight holder f, and a centrifugal weight i having a weight portion g elongated in the generatrix direction and a clutch plate operation portion h extending inward in the radial direction from one end portion of the weight portion is inserted into the transparent window d. , Centrifugal weight i, weight part g
When the centrifugal weight is swung outward in the radial direction by a centrifugal force, the clutch plate is pushed through the operating portion h. It is known that this is done. In this structure, the drum main body b is formed by casting or forging, and a ring-shaped weight holder f is welded to the drum main body b.

[0003]

In the above-mentioned conventional example, since the weight holder f is separate from the drum body b, there is a problem that the number of parts increases and the cost increases.
In view of the above points, an object of the present invention is to provide a clutch drum in which a weight holder is integrated with a drum body and the number of parts can be reduced.

[0004]

[Means for Solving the Problems] In order to solve the above problems,
In the present invention, a clutch drum of a centrifugal clutch,
A centrifuge having a weight portion that is long in the generatrix direction and a clutch plate operation portion that extends inward in the radial direction from one end of the weight portion on the peripheral wall portion of the drum body that forms a spline that engages the clutch plate. A weight holder that forms a long transparent window in the generatrix direction into which the weight is inserted, and abuts one end of the weight portion at a portion near the end wall portion of the drum body to support the centrifugal weight so that the centrifugal weight can swing in the radial direction. In the one in which the drum body is formed by press-molding a sheet metal, leaving a portion of the through window near the end wall portion of the drum body,
The weight holder is formed by the unprinted portion by pushing the unprinted portion outward in the radial direction.

Since the drum body is formed of a press-molded product of sheet metal, the untouched portion of the transparent window can be pushed outward in the radial direction. Then, the weight holder is integrally formed with the drum main body by the unprinted portion, and thus the number of parts can be reduced and the cost can be reduced.

By the way, in the above-mentioned conventional example, the centrifugal weight i is attached to the weight holder f at the edge portion at one end of the weight portion g.
Point contact with the weight holder f.
It is necessary to secure the strength of the point contact portion by forming the with a special material such as super hard metal. In the case where the weight holder is integrally formed with the sheet metal drum body as in the present invention, it is difficult to secure the strength of the point contact portion. In this case, if the mutual abutting surfaces of the one end of the weight portion and the weight holder are formed into arc surfaces having the same curvature, the centrifugal weight will be supported by the weight holder by surface contact, and the surface pressure will be reduced. Since it becomes smaller, the strength of the contact portion between the centrifugal weight and the weight holder is not required to the left, and there is no problem in durability even if the weight holder is integrally formed with the drum main body made of sheet metal.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, reference numeral 1 is a drum body of a clutch drum.
The pressure plate 2, the plurality of clutch plates 3 on the outer side and the inner side 3,
4 and the inner tooth type spline 5 formed on the peripheral wall portion 1a of the drum body 1 and the pressing plate 2 and the outer clutch 3
Are engaged in tooth spaces formed on their outer circumferences, respectively, and a snap ring 6 is attached to an inner peripheral portion of the peripheral wall portion 1a near the open end to prevent the clutch plates 3 and 4 from coming off.

Further, through windows 7 which are long in the generatrix direction are formed at a plurality of locations around the peripheral wall portion 1a of the drum body 1, and a weight holder 8 is provided at a portion of the peripheral wall portion 1a near the end wall portion 1b of the drum body 1. A weight portion 9a provided and long in the generatrix direction
And a centrifugal weight 9 having an operating portion 9b that extends inward in the radial direction from one end of the weight portion 9a, is inserted into the window 7, and one end of the weight portion 9a is brought into contact with the weight holder 8. The centrifugal weight 9 is supported so as to be swingable in the radial direction. An ammunition machine 10 made of a disc spring is provided between the operation portion 9b and the pressing plate 2, and when the centrifugal weight 9 is swung outward in the radial direction by centrifugal force, it is pressed by the ammunition machine 10. The plate 2 is pushed so that the clutch plates 3 and 4 on the outer side and the inner side are brought into pressure contact with each other, thus forming a centrifugal clutch that engages at an increase in rotational speed.

The drum body 1 is formed of a press-molded product of sheet metal. To describe this in detail, first, a spline 5 is formed on the peripheral wall portion 1a of the drum body 1 press-molded into a cup shape as shown in FIG. 3 (A). Is then press-molded, and then the transparent window 7 is punched in the peripheral wall portion 1a as shown in FIG. In this punching, the portion of the transparent window 7 near the end wall portion 1b is left unpunched,
Next, the untouched portion 7a is extruded outward in the radial direction as shown in FIG. 3C, and the weight holder 8 is formed by the untouched portion 7a. In the present embodiment, the peripheral wall portion 1a of the drum body 1 is formed into a stepped shape in which the end portion of the end wall portion 1b has a small diameter, and the step portion 1c between the small diameter portion and the large diameter portion is formed. Starting from the starting point, the untouched portion 7a is extruded radially outward. According to this, the thrust reaction force acting on the weight holder 8 when the clutch is engaged can be received by the small-diameter end portion 1d of the peripheral wall portion 1a, and the supporting rigidity of the weight holder 8 is secured. Further, in the present embodiment, the unleaving portion 7a is extruded by cutting and raising, but the unleaving portion 7a may be extruded radially outward by drawing. in this case,
Since the unprinted portion 7a is continuous with the peripheral wall portion 1a of the drum body 1 at both sides in the circumferential direction, the rigidity of the weight holder 8 is improved. Finally, as shown in FIG. 3D, the mounting groove 11 for the snap ring 6 is formed on the inner peripheral surface of the drum body 1 near the opening end.
To form

Further, in this embodiment, the weight holder 8
The contact surfaces 8a and 9c of the centrifugal weight 9 and one end of the weight portion 9a of the centrifugal weight 9 are formed into arc surfaces having the same curvature.
According to this, the contact between the weight holder 8 and the centrifugal weight 9 becomes a surface contact, and the surface pressure of the contact portion becomes small, so that the strength of the contact portion is not required to the left as compared with the point contact, and is made of sheet metal. Even if the weight holder 8 is integrally formed with the drum body 1 as described above, there is no problem in terms of durability. When the centrifugal weight 9 swings, the contact surface 9c on the centrifugal weight 9 side slides with respect to the contact surface 8a on the weight holder 8 side, but since the centrifugal clutch is used in the transmission in a wet manner, the contact surface 8a and 9c are lubricated with the transmission oil, and the contact surfaces 8a and 9c are not worn.

[0011]

As is apparent from the above description, according to the present invention, since the weight holder can be integrally formed with the drum body, the number of partial points can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a centrifugal clutch including a clutch drum of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

3A to 3D are views showing a procedure for forming a clutch drum.

FIG. 4 is a sectional view of a conventional clutch drum.

[Explanation of symbols]

 1 Drum body 1a Peripheral wall part 1b End wall part 5 Spline 7 Transparent window 7a Left-over part 8 Weight holder 9 Centrifugal weight 9a Weight part 9b Operation part 8a, 9c Contact surface

Claims (2)

[Claims] 1. A clutch drum for a centrifugal clutch, wherein a weight portion elongated in a generatrix direction and a radially inward direction from one end portion of the weight portion are formed on a peripheral wall portion of a drum body having a spline for engaging a clutch plate. A long permeable window is formed in the generatrix direction into which a centrifugal weight having a clutch plate operating portion that bends and extends is formed, and a portion of the drum body near the end wall portion abuts one end portion of the weight portion. In a weight holder that supports a centrifugal weight so that it can swing in the radial direction, the drum body is formed by a press-molded product of sheet metal, and the portion of the window that is close to the end wall of the drum body is left untouched. A clutch drum for a centrifugal clutch, characterized in that a weight holder is formed by the unstruck portion by pushing the remaining portion outward in the radial direction. 2. The clutch drum for a centrifugal clutch according to claim 1, wherein the mutual abutting surfaces of the one end of the weight portion and the weight holder are formed into arc surfaces having the same curvature.