JPS61109966A - Multi-grooved v pulley - Google Patents

Abstract

PURPOSE:To promote the cooling of a pulley by forming an annular space between pulley elements, said space being open at its top to allow the passing of air. CONSTITUTION:One pulley 1, the other pulley 2 and a hollow shaft 3 of a two- stage pulley are integrally made of the same material. The pulleys 1, 2 have a V-groove 1a, 2a defined by respective pulley elements 5, 6. An annular space 7 having a triangular section is formed by adjacent pulley elements 5, 6, and its top 8 has parallel faces. Therefore, as the annular space of the multi-grooved V pulley acts as an air passage, the cooling of the pulley is promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a multi-groove V pulley, and more particularly to a multi-groove V pulley suitable for electrical components used in high-speed rotation such as automotive alternators.

[Background of the invention]

In conventional multi-groove V-boots, as disclosed in Japanese Utility Model Publication No. 40-5085, V-grooves are usually formed directly on the outer periphery of a cylindrical member. This V-groove is mainly formed by rolling or casting, or by drawing an iron plate.

However, when V-grooves are provided directly on the base material,
Since it is heavy, the mounting equipment must be designed to be completely rigid. There has been a problem in that the frictional heat generated by the belt is directly trapped in the pulleys and has a thermal effect on the belt, shortening the life of the belt.

On the other hand, so-called sheet metal pulleys made of iron plates are one step better than the former in that they can be made lighter, but they have no difference in heat dissipation and have the same effect on the belt. Furthermore, the iron plate drawing method has the problem that it is difficult to form when the V-groove spacing is small or the outside diameter is small, and it is not suitable for mass production at all.

[Purpose of the invention]

An object of the present invention is to provide a multi-groove V-pulley that is lightweight and has excellent heat dissipation.

[Summary of the invention]

Multi-groove V-pulleys are extremely common and versatile, but they are difficult in terms of weight.On the other hand, the steel plate drawing method is difficult to form when the V-groove spacing is small or the outer diameter is small. There is a certain drawback. In the end, integral castings became common, but they still have problems in terms of weight and heat dissipation. As a means to solve this problem, we adopted a cold forging method, which attempts to solve the problems of weight and heat dissipation all at once.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. Figure 1 shows the appearance of a multi-groove V pulley made of iron.
One pulley 1, the other pulley 2, and the hollow shaft 3 of the two-stage pulley are integrally molded from the same material. FIG. 2 shows a longitudinal section in the middle of FIG. 1, and pulleys are formed concentrically around the boss portion 4. As shown in FIG. Each of the pulleys 1.2 has a V-groove 1a, 2ai, each of which is separated by a pulley piece 5.6. An annular space 7 having a triangular cross section is formed between the adjacent pulley pieces 5 and 6, and a top portion 8 of the space 7 is formed between the adjacent pulley pieces 5 and 6.
are parallel and facing each other. The pulley pieces 5 and 6 are made to have the same thickness in consideration of the forming method described later.

Next, the method of forming the main boob will be explained with reference to FIGS. 3 and 4. The pulley material is selected from a material suitable for cold-open forming, such as steel or aluminum. First, a member that integrates the hollow part 3 and boss part 4 is formed concentrically by cold forging, and the outer periphery of the member has grooves. As shown in Fig. 3, grooves 1r and tz with a width matching the V-belt width are formed by cutting, and a groove t3 with a width larger than (about twice) t1+42 is similarly formed between them. . In this state, the double walls 51.6 each partition the grooves.
1 is the uniform thickness t? I keep it.

Next, the intermediate part has a rolled W having a V-shaped cross section in each groove.
9, 1 Ot- The grooves are expanded into a V-shape by pressing at the same time to form a boob groove. Here, the outside of the pulley pieces 5 and 6 can be formed very easily since layers can be easily used, but the inside is as shown in FIG.

As shown in FIG. 2, since a facing space is required, the rolling mold 9 is placed in a rolling mold 11 of an amount equal to the required space.
．． It is inserted at the same time as IO, and a V-groove is formed in balance. That is, the opposing space (parallel surface) K rolling die 11 is inserted, and the V-shaped cross-sectional rolling die 9, to suppress the wall that is about to expand outward due to compression, making it possible to create a V-shaped shape due to pressure sound that exceeds elastic deformation. I have to. This molding method is the lightest and allows flexibility in terms of strength.

Further, in the multi-groove V pulley obtained in this example, the annular space serves as an air passage, facilitating cooling of the pulley. Therefore, the rise in temperature of the belt can be suppressed by actively radiating heat, and the life of the belt can be greatly extended. On the other hand, during the forming process, the V-groove surface is plastically worked, so the surface hardness becomes flat, resulting in excellent wear resistance.

As described above, according to the present invention, a multi-groove V pulley that is lightweight and has excellent heat dissipation properties is provided.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is an external view of a multi-groove V pulley, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 f'i shows the first forming process. Fig. 4 is a cross-sectional view of main parts showing the final process.
a, 2a...Pulley groove, 5, 6...Pulley piece, 7.
...Annular space.

Claims (1)

[Scope of Claims] 1. In a multi-groove V pulley in which a plurality of pulley grooves are formed in parallel in the axial direction, an annular space having a substantially triangular cross section is formed between the pulley pieces between adjacent pulleys, and the space A multi-groove V pulley characterized by an open top. 2. The multi-groove V-pulley according to claim 1, wherein the top openings have parallel surfaces and face each other. 3. The multi-groove V-pulley according to claim 1, wherein both pulley pieces forming the V-groove have the same wall thickness.