JPS59190529A - Metal torsion bar and producing method thereof - Google Patents

Abstract

PURPOSE:To improve durability of a torsion bar by aligning the fiber direction of a metal material with the direction of maximum main stress of the torsion bar. CONSTITUTION:The fiber direction 12 of rolled metal material 11 constituting a torsion bar 10 extends at an angle alpha to the center axis X-X of the torsion bar 10. Also, this fiber direction 12 is selected to coincide with the direction 4 of the maximum main stress received by the torsion bar 10 under a load.

Description

[Detailed description of the invention] It is related to the manufacturing method.

Conventionally, rolled metal materials are used as they are for the material of metal torsion bars, but in this state,
The most advantageous fiber direction in terms of material strength is the longitudinal direction. However, when a torsion bar with a circular cross section is manufactured using such rolled metal material, the direction of the most severe stress in terms of strength when the torsion bar is loaded is in the longitudinal direction of its surface. On the other hand, it is the direction of maximum principal stress which is generally 7ta0. Therefore,
When a rolled metal material is used as the material for such a torsion bar.

The most advantageous direction in terms of material strength for rolled metal materials.

There was a large difference between the direction of the maximum principal stress that the torsion bar experienced during loading.

Now, to show this in a schematic diagram, as shown in Figure 1 of the attached drawings, when the torsion bar l is made from a rolled metal material 1, the fiber direction 3 of the metal material The center of /.

Although it extends in the same longitudinal direction as the axis X-X, as shown in Figure 1, the torsion bar/twisting moment)
When T is applied, the surface has its central axis X-
With respect to It can be seen that the direction of the stress is different from the direction of the stress.
It can be seen that conventional metal torsion bars do not fully utilize the original strength of the rolled metal material from which they are made.

The object of the present invention is to obtain a torsion bar that can advantageously utilize the inherent strength of the material when the torsion bar is made from a rolled metal material, and to obtain a method for manufacturing the same. be.

In order to achieve this object, the present invention is characterized in that the fiber direction of the rolled metal material and the direction of the maximum principal stress that the torsion bar receives during loading are substantially the same direction, and .

In order to achieve this, when manufacturing torsion bars from rolled metal materials, hot torsion plastic working is applied to the metal materials before the torsion bars are hardened. It is something to do.

Hereinafter, five embodiments of the present invention will be explained based on FIG. 3 of the accompanying drawings showing an embodiment thereof.

First, FIG. 3 shows the torsion bar 10 according to the present invention.
Although this is a schematic diagram showing an embodiment, in this torsion bar 70, as shown in the figure.

Fiber direction of the rolled metal material // 7.2
As shown in the figure, the center axis X of the torsion bar 70
The fiber direction 1-1 extends in the direction of an angle α with respect to selected.

As described above, in the torsion bar 10 according to the present invention, when a torsion moment T is applied to the torsion bar 10, the direction of the maximum principal stress generated on the surface thereof is the direction of the fibers of the rolled metal material l/,! (!: They are practically in the same direction.

In addition, in order to manufacture such a torsion bar 70 according to the present invention, a rolled metal material as shown in FIG. molded according to substantially the same manufacturing process, but
Torsion bar I after forming during its manufacturing process
Immediately before the O hardening, the torsion bar 10 is subjected to hot torsional plastic working, thereby forming the rolled metal material that is the material of the torsion bar 10.
The fiber direction /2 of the material is made to approach a predetermined angle α with respect to the central axis XX of the material. Note that the direction of torsional plastic working in this case is the same as the direction of the torsional moment T that is applied when the torsion bar IO is used as a product.

Further, it is desirable to immediately quench the material after hot torsion plastic working is performed on the material.

The torsion bar according to the present invention has the above-described configuration and is manufactured by the above-described method.Next, the present invention will be described with reference to examples.

Example Effective diameter 30mm from spring copper (J Engineering SG gθ/).

For two types of torsion bars with effective length /, θθθam, which were subjected to hot torsion plastic processing by the method of the present invention and those which were not subjected to such processing, the number of twists / gO rotation / min speed was calculated. A cyclic torsional fatigue test was conducted.

As a result, the torsion bar according to the present invention is as follows.

It was confirmed that durability could be improved by 37% compared to conventional torsion bars.

As described above, according to the present invention, it is possible to provide a torsion bar with significantly improved durability compared to conventional torsion bars, and to achieve the same durability with a torsion bar having smaller dimensions. In addition, it can be manufactured by using existing equipment as it is or with slight modifications, without requiring any special equipment.
It exhibits various excellent effects such as being able to be manufactured in a relatively low order.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the fiber direction of a rolled metal material that is a raw material for a conventional torsion bar. Fig. 1 is a schematic diagram showing the direction of the maximum principal stress generated on the surface of the torsion bar when a torsion moment is applied to the torsion bar, and Fig. 3 is a diagram showing the fiber direction of the rolled metal material that is the material of the torsion bar according to the present invention. FIG. /, IO taste and torsion bar; ,2. // @・Metal material;, 7. /, 2...fiber direction; ri...principal stress direction;
T...Torsional moment. Patent applicant Mitsubishi Steel Corporation

Claims (1)

[Claims] / A metal torsion bar characterized in that the fiber direction of the rolled metal material that is the raw material substantially coincides with the direction of the maximum principal stress generated on the surface during loading. 2. When manufacturing a metal torsion bar using a rolled metal material as a raw material, after forming the torsion bar from the raw material and before quenching it, the material is subjected to hot welding plastic processing, and the fiber direction of the torsion bar is A method for manufacturing a metal torsion bar, characterized in that the direction of the maximum principal stress that occurs on the surface of ~ during loading is approximately the same as the direction of the maximum principal stress. 3. The manufacturing method according to claim Ω, wherein the material is subjected to hot-swelling plastic working, and then quenching is performed immediately thereafter.