JPH07127715A - Pulley - Google Patents

Abstract

PURPOSE:To scatter load at the fastening time of a boss, and securing sufficient strength of the boss. CONSTITUTION:A center cylindrical boss 1 is fitted and fixed to a rotary shaft S. A ring-like belt winding part 3 is concentrically arranged outside of the boss 1. A plate-like main body 2 connects the boss 1 to the belt-like winding part 3. The boss 1, the main body 2, and the belt winding part 3 are integrated through press-molding of a plate member. An opening edge of the cylindrical boss 1 is bent perpendicularly to the outer direction to form a reinforcing flange 11 having a specified width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley, and more particularly to a structure of a pulley which is simple and lightweight and has sufficient strength.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of reducing the weight of a pulley and reducing the manufacturing cost, it has been attempted to manufacture a pulley main body by press molding a plate material instead of a conventional thick cast product. An example thereof is shown in FIG. In the figure, a disk-shaped pulley main body 2 and a pulley suspension 3 having a constant width bent at a right angle from the outer periphery thereof are formed by integrally press-molding a metal plate. The central boss portion 1 is a thick-walled metal cylinder body, is manufactured by casting, and is fitted into the central opening of the pulley main body portion 2 and fixed by welding. The tip small diameter portion S1 of the rotary shaft S is inserted into the cylinder of the boss portion 1, and the nut N is coupled to the small diameter portion so that the boss portion 1 is provided between the nut N and the large diameter end surface of the rotary shaft S. It is pinched and fixed.

[0003]

The use of a thick cast product for the boss portion 1 is to ensure sufficient strength against the nut tightening load and to make contact with the end surface of the large diameter portion of the rotating shaft S. It is to secure the area and to distribute the tightening load.
However, since it is necessary to manufacture only the boss portion 1 separately, labor and cost are required, and reliability of welding and fixing to the pulley body portion 2 is difficult. Further, due to the presence of the thick metal boss portion 1, it is difficult to significantly reduce the weight of the pulley.
Therefore, as shown in FIG. 6, the pulley main body 2 and the central cylindrical boss portion 1 are integrally formed by press molding of a metal plate, and the reinforcing ring 4 is fitted to the outer periphery of the tip opening of the thin boss portion 1. ,
It has been proposed to secure a contact area with the end surface of the large-diameter portion of the rotating shaft S and prevent the opening deformation of the tip opening of the boss portion 1 due to a tightening load. However, this also does not reduce the labor for separately manufacturing and assembling the reinforcing ring 4, and the cost reduction is still insufficient. The present invention solves such a problem, and an object of the present invention is to provide a pulley which is capable of distributing the load when tightening the boss portion and has sufficient boss portion strength, which is simple to manufacture and inexpensive.

[0004]

The structure of the present invention will be described. A central cylindrical boss portion 1 fitted and fixed to a rotary shaft S,
A pulley comprising a ring-shaped belt suspension portion 3 concentrically arranged outside the boss portion 1 and a plate-shaped main body portion 2 connecting the boss portion 1 and the belt suspension portion 3, at least The boss portion 1 and the main body portion 2 are integrally formed by bending a plate material, and the opening edge of the cylindrical body of the boss portion 1 is bent at a right angle outside the cylinder to form a reinforced flange 11 having a predetermined width. is there.

[0005]

In the above structure, since at least the boss portion 1 and the main body portion 2 are integrally molded, the manufacturing is simple and the cost is low. Further, since the reinforcing flange 11 having a predetermined width is formed on the cylindrical opening edge of the boss portion 1 that comes into contact with the large diameter end surface of the rotating shaft S, the tightening load is dispersed, and the opening edge at the time of tightening is expanded. Deformation is also prevented. Due to the existence of the reinforced flange 11, the conventional reinforcing ring is unnecessary, and the labor and cost of manufacturing and assembling can be further reduced.

[0006]

Embodiment 1 In FIG. 1, a pulley has a central cylindrical boss portion 1, a large diameter cylindrical belt suspension portion 3 located outside the boss portion 1, and these boss portion 1 and belt suspension portion 3 And a circular ring plate-shaped main body 2 connecting the two, which are integrally formed by bending a relatively thin (for example, 2.8 t) SPCC plate material by pressing. A large number of belt suspension grooves 31 are formed on the outer peripheral surface of the belt suspension portion 3 by spinning. On the other hand, the boss portion 1 has a large diameter in the half portion 12 on the body portion 2 side where the boss portion 1 is continuous, and the remaining half portion 13 Has a small diameter with steps. Then, the opening edge of the small-diameter half portion 13 is bent outward at a right angle over the entire circumference (FIG. 2) to form a reinforced flange 11 having a predetermined width.

A small-diameter tip portion S1 of the rotary shaft S is inserted in the small-diameter half portion 13 of the boss portion 1, and a nut N is coupled to the tip portion S1 protruding into the large-diameter half portion 12, The boss portion 1 is provided between the nut N and the end surface of the main body of the rotating shaft S having a large diameter.
The small-diameter half 13 of is fastened and fixed. In this tightened state, the reinforced flange 11 having a predetermined width contacts the end surface of the rotating shaft S, so that the tightening load is dispersed by the flange surface, and stress concentrates on the contact portion between the boss portion 1 and the rotating shaft S. Problems such as damage can be avoided. In addition, as a result of the presence of the reinforcing flange 11, the strength of the opening edge of the small-diameter half portion 13 is improved, and as a result, the opening is not expanded and deformed under the tightening load.

[0008]

[Embodiment 2] FIGS. 3 and 4 show another embodiment of the present invention in which the small-diameter half portion 13 of the boss portion 1 has a cylindrical wall formed in a circumferential direction of 4.
The reinforcing ribs 14 are formed by bending and protruding in an arc shape at three places (of which three are shown). Due to the reinforcing ribs 14, the thin boss portion 1 does not deform even when the tightening load is increased, and exhibits sufficient strength.

In each of the above embodiments, the pulley having the belt suspension portion 3 which is continuous with the pulley main body portion 2 has been described, but in the torsion damper pulley, the belt suspension portion is further provided on the outer side through the rubber layer. It is normal that the mass-shaped body also serves. Therefore, in this case, up to the outer peripheral flange of the main body portion 2 to which the rubber layer is joined, which has substantially the same shape as the belt suspension portion of each of the above-described embodiments, is press-formed integrally with the boss portion 1. Also in this case, the same effect as that of each of the above embodiments can be obtained.

[0010]

As described above, according to the pulley of the present invention,
Since at least the pulley main body and the boss can be manufactured by integral molding using a press or the like, the manufacturing is simple and lightweight. In addition, by forming a reinforced flange on the boss, sufficient boss strength can be achieved without providing a separate reinforcing ring, etc., and the load on the mating member when tightening and fixing the boss is well dispersed. can do.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view of a pulley according to a first embodiment of the present invention.

FIG. 2 is a front view of a boss portion, and is an enlarged view taken along arrow A in FIG.

FIG. 3 is an overall vertical sectional view of a pulley according to a second embodiment of the present invention.

FIG. 4 is a front view of a boss portion, and is an enlarged view taken along the arrow B in FIG.

FIG. 5 is an overall vertical sectional view of a conventional pulley.

FIG. 6 is an enlarged sectional view of a boss portion of a conventional pulley.

[Explanation of symbols]

 1 Boss part 11 Reinforced flange 2 Body part 3 Belt suspension part

Claims (1)

[Claims] 1. A central cylindrical boss portion that is fitted and fixed to a rotating shaft, a large diameter cylindrical belt suspension portion that is concentrically arranged outside the boss portion, and these boss portions and a belt. A pulley composed of a plate-shaped main body portion connecting suspension parts, wherein at least the boss portion and the main body portion are integrally formed by bending molding of a plate material, and the opening edge of the cylindrical body of the boss portion is perpendicular to the outside of the cylinder. A pulley characterized by being bent to form a reinforced flange of a predetermined width.