JPH08247191A - Tension spring - Google Patents

Abstract

PURPOSE: To provide a tension spring in which the hook part is difficult to slip from a through hole of an attaching part, assembling workability can be improved, and the function of a stopper is provided by making a double structure through a process of turning over the hook part. CONSTITUTION: In a tension spring 10, since a hook part 10b is turned over and a double structure is formed, the action part of tensile stress is made into a double structure, and the strength of the action part of tensile stress is improved. Therefore, the hook part 10b can be made into a structure wherein it is not easily deformed and it is difficult to slip from a through hole 31a. Since the turning-over point part is made into a tip 10a of the hook part 10b by turning over of the hook part 10b, the tip 10a is roundish, and it is easily inserted into the through hole 31a, and assembling workability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension spring, and more particularly to a tension spring used for opening and closing a door portion of an audio device or the like.

[0002]

2. Description of the Related Art FIG. 3 (a) is a schematic front view showing a main portion of a conventional tension spring 30 of this type.
(B) is a schematic perspective view showing a state in which the tension spring 30 is assembled to the assembly side 31. Tension spring 30
Has a coil shape and exhibits elasticity in the direction of arrow A in the figure, and generally has a total length of about 5 to 100 mm.
A through hole 31a having a diameter slightly larger than the cross-sectional diameter (not shown) of the tension spring 30 is formed on the assembly side 31. To assemble the tension spring 30 to the mounting side 31, from the tip portion 30a of the tension spring 30,
The through hole 31 is formed so that the hook portion 30b follows the curved shape.
Insert into a and assemble. The tension spring 30 thus assembled is stretched between the assembling side 31 and the other assembling side (not shown).

[0003]

However, in the tension spring 30 having the above structure, when a large tensile stress greater than the strength of the hook portion 30b acts on the hook portion 30b, or the number of times the tensile stress acts is large. However, there is a problem that when the strength of the hook portion 30b becomes unbearable due to fatigue, the hook portion 30b is deformed and the tip portion 30a is easily removed from the through hole 31a.
Further, since the tip end portion 30a is not rounded, the tip end portion 30a is inserted into the through hole 31a.
There was a problem that assembly workability was poor due to being caught in the peripheral part. For this problem, the tip 3
It is conceivable to round the 0a, but it is difficult because the tension spring 30 itself is very small. Further, even if the above-mentioned deformation of the hook portion 30b does not occur, the stress not in the direction parallel to the elastic direction A causes the tension spring 3 to move.
When it acts on 0, there is a problem that the hook portion 30b is easily removed from the through hole 31a.

The present invention has been made in view of the above problems, and provides a tension spring having a hook portion that does not easily come off from a through hole of a mounting portion, can improve workability in assembling, and has a function of a stopper. It is intended to be provided.

[0005]

In order to achieve the above object, the tension spring according to the present invention is characterized in that the hook portion is folded back to form a double structure (1).

The tension spring according to the present invention is characterized in that the hook portion is folded back to form a retaining portion (2).

[0007]

According to the tension spring (1) of the present invention, since the hook portion is folded back to have a double structure, the portion acting on the tensile stress has a double structure. Strength will be strengthened. Therefore, the hook portion is less likely to be deformed, and is less likely to fall out of the through hole. Further, since the hook portion is folded back, the folding point portion becomes the tip end portion of the hook portion, and the tip end portion is rounded, so that the hook portion is easily inserted into the through hole, and the assembling workability is improved.

Further, according to the tension spring (2) of the present invention, since the hook portion is folded back to form the retaining portion, the retaining portion is assembled with the retaining portion after being inserted into the through hole. Since it is locked to the side, the hook portion is less likely to fall out of the through hole.

[0009]

Embodiments of the tension spring according to the present invention will be described below with reference to the drawings. FIG. 1A is a schematic front view showing a main part of a tension spring 10 according to a first embodiment of the present invention, and FIG.
FIG. 3 is a schematic perspective view showing a state of being assembled to No. 1. The tension spring 10 has a coil shape, and is made of steel wire for spring such as piano wire, has elasticity in the direction of arrow A in the drawing, and the hook portion 10b has a folded double structure. Therefore, the tip portion 10a has a rounded shape. The structure of the assembling side 31 is the same as the conventional one, and the same reference numerals are given. Further, the hook portion 10b is
The maximum cross-sectional area portion is smaller than the diameter of the through hole 31a on the assembly side 31. Tension spring 1
The method of assembling 0 on the assembling side 31 is also similar to the conventional one, and since the tip portion 10a is rounded, it can be smoothly inserted into the through hole 31a. Further, since the hook portion 10b has a double structure, the strength against tensile stress is enhanced.

As described above, in the tension spring 10 according to the first embodiment, since the hook portion 10b is folded back to have a double structure, the portion acting on the tensile stress has a double structure. The strength of the portion where the tensile stress acts will be strengthened. Therefore, the hook portion 10b can be made to have a structure that is hard to be deformed and does not easily fall out from the through hole 31a. Further, since the hook portion 10b is folded back, the turning point portion is the tip portion 1 of the hook portion 10b.
Since it becomes 0a, the tip portion 10a becomes rounded, it becomes easier to insert it into the through hole 31a, and the assembling workability can be improved.

FIG. 2A is a schematic front view showing a main part of the tension spring 20 according to the second embodiment of the present invention.
(B) is a schematic perspective view showing a state in which the tension spring 20 is assembled to the assembly side 31. Tension spring 20
Has a coil shape, is made of the same material as that of the first embodiment, and has elasticity in the direction of arrow A in the drawing. Hook part 2
0b is folded back with the tip 20a as the lower end to form a retaining portion 20c, and therefore the tip 20a has a rounded shape. The structure of the assembling side 31 is the same as the conventional one, and the same reference numerals are given. The maximum cross-sectional area of the hook portion 20b is smaller than the diameter of the through hole 31a on the assembly side 31,
The length x of the retaining portion 20c is formed to be longer than the diameter of the through hole 31a. The method of assembling the tension spring 20 to the assembling side 31 is the same as the conventional method,
Since the tip portion 20a is rounded, it can be smoothly inserted into the through hole 31a. In addition, since the retaining portion 20c functions as a stopper, there is no risk that it will fall out once inserted.

As described above, in the tension spring 20 according to the second embodiment, since the hook portion 20b is folded back to form the retaining portion 20c, the retaining portion 20c is inserted into the through hole 31a. As a result, the hook portion 20b is locked to the assembly side 31, and the retaining portion 20c
Acts as a stopper, so that the hook portion 20b
Is less likely to fall out of the through hole 31a.

In the above-mentioned first and second embodiments, for example, a piano wire was used as the material of the tension spring, but the material is not limited to this, and in another embodiment, a hard steel wire, Spring steel wire such as stainless steel wire for spring, carbon steel oil temper wire for spring, Cr-V steel oil temper wire for spring, Si-Cr steel oil temper wire for spring, Si-Mn steel oil temper wire for spring It may be a steel wire for spring such as brass wire, phosphor bronze wire, beryllium copper wire or the like.

[0014]

As described in detail above, according to the tension spring (1) of the present invention, since the hook portion is folded back to have a double structure, the portion acting on the tensile stress has a double structure. Therefore, the strength of the portion where the tensile stress acts is strengthened. Therefore, the hook portion can be made to have a structure that is difficult to deform and does not easily fall out from the through hole. Further, when the hook portion is folded back, the turning point portion becomes the tip end portion of the hook portion, and since the tip end portion is rounded, it can be easily inserted into the through hole, and the assembling workability can be improved.

Further, according to the tension spring (2) of the present invention, since the hook portion is folded back to form the retaining portion, the retaining portion is assembled with the hook portion after it is inserted into the through hole. Since the retaining portion functions as a stopper because it is locked to the side, the hook portion can have a structure that does not easily slip off from the through hole.

[Brief description of drawings]

FIG. 1A is a schematic front view showing a main part of a tension spring according to an embodiment of the present invention, and FIG. 1B is a schematic perspective view showing a state in which the tension spring is assembled on an assembly side. is there.

FIG. 2A is a schematic front view showing a main part of a tension spring according to another embodiment, and FIG. 2B is a schematic perspective view showing a state in which the tension spring is assembled on an assembly side. .

FIG. 3A is a schematic front view showing a main part of a tension spring according to a conventional example, and FIG. 3B is a schematic perspective view showing a state in which the tension spring is assembled on an assembly side.

[Explanation of symbols]

 10, 20, 30 Tensile springs 10b, 20b, 30b Hook part 20c Retaining part

Claims (2)

[Claims] 1. A tension spring having a double structure in which a hook portion is folded back. 2. An extension spring, wherein the hook portion is folded back to form a retaining portion.