JPS5838175Y2 - tension coil spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tension coil spring having a covering body in which a coil portion is embedded.

In order to impart damping characteristics to the tension coil springs, methods have been used to press-fit soft urethane foam or the like into the coil parts.
In such conventional means, since the retention of the urethane etc. is unreliable, there are problems such as easy detachment, difficulty in smooth operation, and inability to obtain sufficient vibration-proofing and buffering performance.

However, soft urethane foam is strong in compression but weak in tension, making it unsuitable for use in tension coil springs in terms of durability.
Moreover, since it has water absorbing properties, it also has disadvantages such as the tendency for rust to occur in the coil portion.

On the other hand, in the case where the coil part is embedded in a rubber material, due to the characteristics of the rubber material, it is not possible to obtain a large amount of deflection, and the spring constant increases rapidly as the material is expanded. be.

The present invention was developed under the above circumstances, and its purpose is to provide a tension coil spring that has sufficient damping characteristics, excellent vibration-proofing and shock-absorbing performance, and is highly durable. be.

Hereinafter, the present invention will be explained with reference to the illustrated embodiments.

In the first embodiment shown in FIG. 1, a spring body 1 integrally includes a coil portion 2 and hook portions 3, 3 connected to both ends of the coil portion 20, respectively.

The coil portion 2 is entirely embedded within the cylindrical covering 4.

The covering body 4 is formed into a desired shape using a mold, for example, from a soft synthetic resin foam material to which a desired amount of asphalt is added.

At this time, the coil portion 2 is placed in a stretched state in advance in a mold, and the foam material is foam-molded.

According to the above configuration, the coil portion 2 is embedded integrally in the covering body 4, and is filled in a part of the covering body or the gap between the spring wires, and is foamed and bonded to the spring wires, so that the covering body 4 performs correct expansion and contraction operations in response to the expansion and contraction of the coil portion 2, resulting in good and stable damping characteristics.

Therefore, it is possible to prevent the generation of abnormal noise due to surging vibrations and contact between the bone wires, and to reduce the impact load.

Moreover, since the coil part 2 is embedded in the covering body 4 in an expanded state, the covering body 4 is in a compressed state when the coil part 2 is in a free state, and the covering body 4 is substantially expanded even when the coil part 2 is in a stretched state. Never.

Therefore, even if the material is a soft urethane foam that is strong in compression but weak in tension, it does not generate large tensile stress, so durability can be improved.

Moreover, since asphalt is added to the coating 4, the rust prevention performance can also be improved by improving the waterproof property.

In the second embodiment shown in FIG. 2, the covering body 4 has a solid rod shape, and has hook portions 3 and 30 bases embedded in both ends, and other features are substantially the same as in the first embodiment. are configured equally.

In this second embodiment, the same effect as in the first embodiment can be achieved, and since there is no hollow part, the mold for molding the covering is simpler and molding is easier, and the hook part 3 , 3 has the effect of preventing dislodgement, damage, etc.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the coil portion 2 may be partially embedded in the cover 4 instead of the entire coil portion 2, and the shape of the hook portion 3 or the The presence or absence and the shape of the covering 4 can be arbitrarily set.

multiple cases as illustrated in Figure 3 (the figure shows the case of two)
It is also applicable to a case where the coil portions 2, 2 are provided.

Further, as illustrated in FIG. 4, a rubber coating 5 may be applied to the covering body 4 to improve waterproofness.

Furthermore, the substance to be added to the above-mentioned soft synthetic resin foam material is not limited to asphalt alone, and may be any substance consisting mainly of hydrocarbons, such as extender oil, petroleum resin, or an appropriate mixture of these. .

Alternatively, a soft synthetic resin foam impregnated with oil may be used.

In addition, various modifications or applications are possible within the scope of the gist of the present invention.

In the present invention, as described above, the covering body in which the coil portion is embedded is formed from a soft synthetic resin foam material to which at least one of asphalt, tar, extender oil, and petroleum resin is added. Rust prevention performance can be improved.

In addition, the coil portion is pre-stretched and embedded in the covering,
Since the covering was made to be compressed in the free state,
It can improve durability by compensating for the weakness of soft synthetic resin foam materials, which are weak against tension.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view showing one embodiment of the present invention, FIG. 2 is a cutaway side view showing another embodiment of the present invention, and FIGS. 3 and 4 are cutout side views showing modified examples of the present invention. FIG. 1...Spring body, 2...Coil part, 3
, 3... Hook portion, 4... Covering body.

Claims (1)

[Scope of utility model registration request] At least a portion of the stretched coil portion is buried in a covering made of soft synthetic resin foam to which at least one of asphalt, tar, extension oil, and petroleum resin is added, and the above-mentioned covering is in a free state. A tension coil spring characterized by having a compressible body.