JPS6229127B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a W pulley.

For example, in car coolers, an electromagnetic clutch with a W pulley is sometimes used to turn on and off power transmission between the car engine and the refrigerant compressor. Conventional electromagnetic clutch pulleys are generally made by forging and then cutting. However, pulleys made by such a method have the disadvantages of being heavy and having a poor material yield.

Therefore, the present invention provides W
The purpose is to provide a method for manufacturing pulleys.

The method for manufacturing a W pulley according to the present invention includes preparing a metal cylinder having a short axial length, and making the cylindrical body bulge outward and crushing it in the axial direction at the axial middle part of the cylinder. forming a ring-shaped bead part; pushing apart both axial ends of the cylindrical body to form a tapered part; further pushing out the tapered part and shaping it; and making the bead part V-shaped in cross section. Including opening. The thin W pulley element thus obtained is further fitted and fixed to the outer periphery of a separately manufactured rotor.

Examples will be described below with reference to the drawings.

First, as shown in FIG. 1a, a ring-shaped pipe or cylindrical body 1 having a short axial length is prepared by rolling and joining iron plates and cutting them into a fixed size. As shown in FIG. 2a, this cylindrical body 1 is positioned between the vertically paired first dies 2 and 3 with their axes substantially aligned. Then, as shown in FIG. 2b, for example, the upper die 2 is lowered. In this way, the axially intermediate portion of the cylindrical body 1 is bulged outward and crushed in the axial direction, thereby forming an outwardly bulging ring-shaped bead portion 1a as shown in FIG. 1b.

Next, the cylindrical body 1 having this bead portion 1a is
As shown in Figure a, the vertically paired second dies 4 and 5 are positioned with their axes substantially aligned. For example, by lowering the upper die 4, second dies 4 and 5 are press-fitted into both axial ends of the cylindrical body 1, respectively, as shown in FIG. 3b. As a result, as shown in FIG.
is formed into a semi-finished product 1'. Since the axially intermediate portion of the cylindrical body 1 is reinforced by the ring-shaped bead portion 1a in this way, the two dies 4 and 5 are used to cut only the axially both ends of the cylindrical body 1 with concern for dimensional accuracy. The predetermined bead portion 1b can be easily formed by enlarging the bead portion 1b.

Next, this semi-finished product 1' is set in the shaping device 6 as shown in FIG. 4a. The shaping device 6 is a semi-finished product 1'
It includes an outer die 7 corresponding to the outer side of the die, and an upper and lower pair of inner dies 8 and 9. The outer die 7 is a ring-shaped piece divided into a plurality of pieces in the circumferential direction, and is placed on the cushion plate 11, and when it descends while compressing the cushion 12, it enters the inside of the guide cylinder part 13, thereby causing be integrated. Also, one of the paired inner dies 8 and 9 has a circular convex portion 14 that is press-fitted into the inside of the set semi-finished product 1', and the other has a concave portion 15 that escapes from the convex portion 14. ing.

Now, in the shaping device 6 in which the semi-finished product 1' is set, the upper inner die 8 is lowered as shown in FIG. 4b. Then, the semi-finished product 1' is pushed by the die 8 and descends together with the outer die 7 while compressing the cushion 12. As a result, the outer die 7 enters the inside of the guide tube portion 13, thereby firmly pressing the semi-finished product 1' from the outside.

When the upper inner die 8 further descends, the inner dies 8 and 9 are press-fitted inside the tapers 1b at both axial ends of the semi-finished product 1'. In this way, the tapered portion 1b is further expanded by the inner dies 8 and 9 and pressed against the outer die 7, and is shaped as shown in FIG. 1d. In this way, semi-finished product 1'
Since the axially intermediate portion of is reinforced by the bead portion 1a, the tapered portion 1b can be easily shaped using the outer die 7 and the inner die 8. If the pressing force of the upper inner die 8 is released and if necessary the die 8 is pushed up, the semi-finished product 1'' is pushed up by the cushion 12.

Next, this tapered part 1b is shaped into a semi-finished product 1''
is set in a finishing forming device 16 as shown in FIG. 5a. This finishing forming device 16 includes an outer periphery forming roller 17 which is a ring-shaped roller divided into a plurality of pieces in the circumferential direction, and a V-groove forming roller 18 inserted inside the ring-shaped roller 17 at intervals. I'm here. The V-groove forming roller 18 has a ring-shaped protrusion 19 with a triangular cross section on its outer peripheral surface.

For finishing forming, the semi-finished product 1'' is set inside the outer periphery forming roller 17, and the V-groove forming roller 1 is
8 inside, and while rotating both rollers 17 and 18 in the same direction, shift the axes as shown in FIG.
Press it against the back of the As a result, the bead portion 1a is pushed open to have a V-shaped cross section as shown in FIG. 1e.
In this way, the V-groove 1c receives the V-belt on the outer periphery.
A pulley element 1 having two is obtained. The cross-sectional shape of the ring-shaped protrusion 19 is made to match the angle of the V-groove 1c when completed.

Such a pulley element 1 is finally fitted and fixed to the outer periphery of a rotor (not shown), thereby forming a W pulley.

As described above using the embodiments, according to the present invention, the weight and cost of the W pulley can be reduced, the amount of unbalance can be reduced, and the material yield can be improved. In particular, a ring-shaped bead is formed in the axially intermediate part of the metal cylindrical body by bulging outward and being crushed in the axial direction, and in this state, both axial ends of the cylindrical body are reinforced. Since the tapered part is formed by expanding the , the tapered part can be easily formed without worrying about dimensional accuracy.
Furthermore, since the axially intermediate portion is reinforced with a bead portion, the tapered portion can be easily shaped.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the manufacturing procedure of the W pulley according to the present invention in the order of a to e, and Figs. 2 to 5 show specific examples of each manufacturing process, in which a is before processing, b is is an explanatory diagram of the state after processing. 1... Cylindrical body, 1', 1''... Semi-finished product, 1...
Pulley element, 1a...bead part, 1b...tapered part, 1c...V groove.

Claims (1)

[Claims] 1. Preparing a metal cylindrical body with a short axial length, and forming a ring-shaped bead portion in the axially intermediate portion of the cylindrical body by expanding it outward and crushing it in the axial direction. , expanding both axial ends of the cylindrical body to form a tapered portion;
A method for manufacturing a W pulley, which includes further expanding and shaping the tapered portion, and opening the bead portion to a V-shaped cross section.