JPS59190527A - Metal coil spring and producing method thereof - Google Patents

Abstract

PURPOSE:To improve strength by aligning the fiber direction of metal material as strand with the direction of main stress produced in a spring. CONSTITUTION:A torsional process T is added to the production process I of rolled metal material 1 and after the fiber direction F1 of the metal material 1 is directed at an angle alpha to the center line X-X of the metal material, a metal coil spring is formed of the metal material 1 as strand. The fiber direction F1 is selected to align with the direction of main stress produced on the surface of the strand when the coil spring is subjected to a load.

Description

[Detailed description of the invention] The present invention relates to a spring and a method for manufacturing the same.

Conventionally, in rolled metal materials for metal coil springs, the fiber direction of the material was aligned in the longitudinal direction of the strands of the coil. In other words, in the material for hot-formed coil springs, the fiber direction of the hot-rolled material is directly in the direction of the edge of the strand of the coil, and the material for cold-formed coil springs is In this case, the direction of the fibers due to rolling or drawing of the material was directly in the direction of the heel of the strands of the coil. 4 Now, if I were to explain this using a diagram, it would look like the first order of magnitude. In other words, in FIG. 1 of the attached drawings, the reference numeral 1 indicates a part of a metal material for hot-formed coil springs or for cold-formed coil springs, and in this case, the fiber direction F of this metal material is 9 coincides with the central axis X-X of the material l, and as shown in Fig.
When a coil spring is formed using strands, the spiral direction Y-Y of the strands of the coil spring is the fiber direction F of the metal material l.
It matches.

However, as is well known, when a load is applied to a compression or tension coil spring Ω formed from such hot-forming or cold-forming spring metal material l as a wire, the compression or tension coil spring Ω is The strand of spring λ is
Mainly, torsion moment acts, and therefore, the most severe strength is on the surface of the wire in the longitudinal direction Y.
-, the direction from Y to approximately G S0 (principal stress direction).

On the other hand, the strength of the material is strongest in the fiber direction F.

In this way, when a conventional compression or tension metal coil spring is subjected to a load, the direction of the principal stress generated on the surface of the wire and the strength of the material forming the wire are determined. Since the direction of the strong fibers does not match, there is a drawback that the strength of the material is not fully demonstrated as a spring product.

Therefore, an object of the present invention is to obtain a compression or tension metal coil spring that can fully utilize the inherent strength of the metal material as a wire, and to obtain a method for manufacturing the same. be.

In order to achieve this object, the metal coil spring according to the present invention is characterized in that the fiber direction of the metal material as a wire is made to match the direction of the principal stress generated in the spring. This makes it possible to effectively utilize the material strength. Furthermore, the method of the present invention
In order to achieve this purpose, we either apply torsional plastic working to a rolled metal material that has been previously subjected to torsional plastic working and then form a metal spring using the strands, or we apply torsional plastic working to a rolled metal material that is a strand, and immediately after that It is characterized by being formed into a metal coil.

Hereinafter, the present invention will be explained based on Figures 3 and 3 of the accompanying drawings showing embodiments thereof.

As mentioned above, the present invention is characterized in that the direction of the principal stress applied to the strands of the compression or tension metal coil spring is made to substantially match the direction of the fibers of the rolled metal material as the strands. In order to realize this, the following two methods can be considered.

In other words, the first method, as shown in FIG. This is a method in which the metal material is oriented in a direction having a certain angle α with respect to the center line XX, and then this is formed into a metal coil spring as a wire.

As a second method, as shown in FIG.
When forming a metal coil into a metal coil on a mandrel 3, the material l is twisted into a coil wire λ while being twisted T, and the fiber direction F1 of the metal material / is
In this method, the angle α is made to have a certain angle α with respect to the center line XX of the metal control l.

The coil spring according to the present invention can be manufactured by the method described above, and examples thereof will now be described.

By hot working, a spring steel material with a diameter d = / Oyrta (J-C + lIgO) was used as a wire, and a coil spring with an average coil diameter //gwx and an effective number of turns of 6 was made into the above-mentioned first and second coil springs. A durability test was conducted by repeatedly applying a compressive load to each spring, and the durability was compared with that of a conventional spring of the same size and made from spring steel with the same diameter.

As a result, it was found that in the first method, the coil spring made from spring steel which had been subjected to torsional plastic working so as to have F in the fiber direction had a 2-g attack, and in the second method, the coil spring Coil springs with F in the fiber direction by torsion plastic working during the spring manufacturing process have a durability of 33%, compared to the durability of coil springs manufactured using the conventional manufacturing process. It was confirmed that the power improved.

The reason why there is a difference in the durability of the spring between the two methods is thought to be that in the second method, the effect of the processing heat treatment is added to the durability.

In addition, when applying torsional plastic processing to spring metal materials, the direction of the torsional plastic force Loe applied to the spring metal materials depends on whether the coil spring is subjected to a tensile load or a compressive load. shall be in opposite directions.

As described above, in the present invention, when a compression or tension metal coil spring is manufactured using a rolled metal material for a spring as a wire, the direction of the fibers of the metal material for a spring is set when the coil spring is subjected to a load. Since the wire is subjected to torsional plastic processing in a direction that almost matches the direction of the principal stress generated on the surface of the wire, the strength of the material can be effectively utilized as a metal coil spring. , the durability can be significantly increased compared to conventional metal coil springs, or the same durability can be achieved even when using a spring steel material with a smaller diameter. .

In addition, since it is relatively easy to manufacture and does not require special equipment, it is possible to manufacture it in descending order.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the center line of the metal material for springs and the fiber direction; FIG. 1 is a schematic diagram showing the fiber direction in a coiled spring manufactured from the metal material shown in FIG. 1; FIG. 7 is an explanatory diagram showing a construction state in which a spring metal material as a wire of a metal coil spring according to the present invention is twisted.
The figure is an explanatory view showing a state in which a metal coil spring is formed while being twisted during the manufacturing process. /...Metal material for spring; Co-coil spring; 3...Mandrel; F,...fiber direction; T...thread processing.

Claims (1)

[Claims] l In a metal coil spring, the fiber direction of the round cross-section rolled metal material for the spring as the wire is approximately the direction of the principal stress generated on the surface of the metal coil spring when it receives a load. The metal coil is characterized by a matching type of splash. (2) When manufacturing a metal coil spring, the round cross-section rolled metal material for the spring as the strand is subjected to cold or hot torsion plastic working, and then formed into a coil shape. A method of manufacturing metal coil springs. 3 Screw! 11. The manufacturing method according to claim 1, wherein plastic working is previously applied to the round cross-section rolled metal material for the spring. 3. The manufacturing method according to claim 2, wherein the rolled metal material for a spring with a round cross section is immediately formed into a coil spring after torsion plastic working is performed on the rolled metal material.