JPH0681870A - Tension spring - Google Patents

Abstract

PURPOSE:To eliminate a break in a dislocation preventing part while preventing a hook part from easily coming off even when abnormal external force is applied to the hook part to a bracket. CONSTITUTION:A V-shaped fold-back part 2c is formed in the point end of a hook part 2 of a tension spring 1 where a wire rod is helically wound. The fold-back part 2c is elastically deformed and inserted through a hole 3a of a bracket 3. The fold-back part 2c, inserted through the hole 3a, is restored by elastic force, to prevent the hook part 2 from coming off.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in tension springs.

[0002]

2. Description of the Related Art As shown in FIG.
Attach the arc-shaped hook 2 formed at the end of the bracket to the hole 3 of the bracket 3.
If the spring used through a is used for applications such as automobiles where vibration is applied, the hook 2 may be disengaged from the hole 3a due to an external force and may not be used.

In order to prevent such disengagement, as shown in FIG. 5, the end portion of the coil spring 1 is extended in the same direction as the axial center, and the extended portion is bent in a loop shape and is free from play. A tension spring has been proposed in which the hook portion 2 is formed by crossing the end portion with respect to the root portion (Actual No. 52-
26049).

Further, as shown in FIG. 6, the tip 2a of the arcuate hooking portion 2 formed at the end of the coil spring 1 is folded inward so that the hooking portion 2 is formed in the hole 3a of the bracket 3.
A tension spring that has been prevented from coming off is proposed (Japanese Utility Model Publication No. 50-43636).

[0005]

In the prior art shown in FIG. 4, the hook portion is easily disengaged from the hole of the bracket by an external force, and the spring forced disengagement test that does not actually occur is disengaged 6 times in 10 tests. There was a problem.

In the prior art of FIG. 5, since the bending portion 2b is constantly stressed, there is a possibility that the bending portion 2b may break in a short period of time when used in a vibrating application, resulting in poor reliability.

Further, in the embodiment of FIG. 6, the hook portion 2 is provided with the hole 3a.
There is a problem in that, when it is assembled by passing through it, not only is it difficult to assemble because the folded tip 2a interferes, but reassembly is impossible.

Therefore, an object of the present invention is to provide a tension spring which can solve these problems.

[0009]

In order to achieve the above object, the tension spring of the present invention has a V-shaped folded portion (2c) formed at the tip of the hook portion (2).

It is effective to make the dimension H of the opening end of the folded portion (2c) larger than the hole diameter φd of the bracket (3). Further, the folded-back portion (2c) may be formed in a plane different from the arcuate portion of the hooking portion (2).

[0011]

Operation: The V-shaped folded portion (2c) penetrates through the hole of the bracket (3) and the hook portion (2) is hooked,
Even if abnormal external force is applied due to vibration, shock, erroneous operation, etc.
The folded portion (2c) prevents the hooking portion (2) from coming off.

Since no stress is applied to the folded-back portion during use, there is no possibility of breaking this portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIG. 1, 1 is a tension spring formed by winding a wire material having a diameter of 1 mm in a spiral shape, and an arcuate hooking portion 2 is formed at an end thereof.

At the tip of the hook portion 2, a V-shaped folded portion 2 is provided.
c has a length L and an opening end dimension H. Reference numeral 3 is a bracket, and 3a is a hole formed in the bracket 3 for hooking the hook portion 2.

The diameter φd of the hole 3a is 3.3 mm to 3.5 m.
m, opening end dimension H is 2 to 6.5 mm, length L is 5 to 7 m
m. In the embodiment of FIG. 1, the arcuate hooking portion 2 and the V-shaped folded portion 2c are formed in the same plane.

When the tension spring 1 is caught in the hole 3a of the bracket 3, as shown in FIG. 2A, the V-shaped folded portion 2c is elastically deformed to penetrate the hole 3a, and the folded portion 2c is restored. Then, as shown in FIG. 2 (B), it is difficult to pull out from the hole 3a.

1 to 3 show the case where the V-shaped opening end dimension H is larger than the diameter .phi.d of the hole 3a, which is effective for preventing the hook portion from coming off. This is troublesome because the folded-back portion 2c needs to be elastically deformed when it is penetrated.

If the opening end dimension H is slightly smaller than the diameter of the hole 3a, the assembling becomes easy and the detachment can be prevented.
In the embodiment shown in FIG. 3, the arcuate portion and the folded portion of the hooking portion 2 are not formed on the same plane but in the planes intersecting each other at 90 °. However, similar to the embodiment shown in FIG. It has the effect of preventing disconnection.

Thus, the folded-back portion 2c is connected to the hook portion 2
If it is formed in a plane different from the arc-shaped portion of, it may be convenient in assembling and is effective.

[0020]

Since the tension spring of the present invention is constructed as described above, it is easy to assemble, can be prevented from coming off due to an abnormal external force, and since the folded portion is not stressed, it is highly reliable.

Then, the opening end dimension H is defined by the diameter φ of the hole (3a).
If it is larger than d, the prevention of disconnection is more reliable. Further, if the folded-back portion (2c) is formed in a plane different from the arcuate portion of the hooking portion (2), the effect of easy assembly may be obtained.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing an essential part of a state in which a spring according to an embodiment of the present invention is mounted on a bracket.

FIG. 2 is a diagram showing a procedure for mounting the spring shown in FIG. 1 on a bracket.

FIG. 3 is a main part of another embodiment of the present invention, (A) is a front view and (B) is a side view.

FIG. 4 is a partial vertical cross-sectional view of an example of a conventional technique mounted on a bracket.

FIG. 5 is a partial vertical cross-sectional view of another conventional example mounted on a bracket.

FIG. 6 is still another conventional technique, (A) is a front view and (B) is a front view.
Is a side view.

[Explanation of symbols]

 1 Tension spring 2 Hooking part 2c Folding part 3 Bracket 3a Hole

Claims (3)

[Claims] 1. A tension spring having a V-shaped folded-back portion (2c) formed at the tip of a hooking portion (2). 2. The tension spring according to claim 1, wherein the dimension H of the opening end of the folded portion (2c) is larger than the hole diameter φd of the bracket (3). 3. The tension spring according to claim 1, wherein the folded-back portion (2c) is formed in a plane different from the arcuate portion of the hooking portion (2).