JP3000521B2 - spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a synthetic resin spring developed for a mattress and usable as other various cushioning elements and elastic elements.

[0002]

2. Description of the Related Art A mattress used for bedding such as a bed has a large number of metal coil springs, torsion bars and the like uniformly distributed in a flat plate shape. Along with joining in a plane,
A spring whose outer peripheral edge is surrounded by a wire or the like is used. Such a spring generally has not only a complicated structure and poor productivity, but also a large weight, which requires a great deal of labor for handling during transportation, etc. There were problems such as occurrence of cracks and poor consistency with the fiber material portion such as side ground.

[0003] Therefore, as a substitute for the conventional metal spring, a plastic spring that is lightweight, quiet, and has good productivity is being developed. In the case of this plastic spring, it is similar to other plastic products. Therefore, a spring having a completely different shape from the conventional one can be formed, and a sufficient mechanical property can be obtained by compensating for the lack of strength of the material itself due to its shape effect.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention is lightweight, quiet, has good productivity, and allows a large amount of elastic deformation compared to the size of a spring. It is an object of the present invention to obtain a spring capable of performing the above.

[0005]

A plurality of annular members which are integrally formed of a synthetic resin material and which are disposed at appropriate intervals and have the same axis and are arranged in parallel, and a plurality of annular members are arranged at a plurality of positions. The elastic connecting member is arranged along a virtual cylindrical surface formed by each of the annular members, and the spring has an inverted U-shape curved in the circumferential direction of the annular member. The diameter of the annular member is made different between adjacent annular members, and one end and the other end of the elastic connecting member are provided shifted in the radial direction of the annular member so that they do not overlap in the direction of expansion and contraction of the spring. I made it. The annular member has a cut-out portion radially indented or recessed or penetrated in the direction of expansion and contraction of the spring at a position overlapping the curved portion of the elastic connecting member adjacent thereto in the axial direction. Further, the one end and the other end of the elastic connecting member are arranged so as to be shifted in the circumferential direction of the annular member, and the length of the arm on the one end side and the length of the arm on the other end side of the elastic connecting member are made different from each other. A notch may be formed in the annular member connected to the other arm.

[0006]

1 to 4 show a representative embodiment of the spring of the present invention, which will be described below with reference to the drawings.

In the drawing, a spring 1 of the present invention comprises a central annular member 2, two annular members 3 and 3 having a distance d on both upper and lower sides thereof and having the same axial center and being arranged in parallel.
And a plurality of inverted U-shaped elastic connecting members 4 for connecting the respective annular members 2, 3, 3 to each other at three locations on the circumference.

Among the annular members 2, 3, 3, the upper and lower annular members 3, 3 have the same diameter r3, and the central annular member 2 has the same diameter r2 as the upper and lower annular members 3, 3. It is set to be relatively smaller than that.

Each of the elastic connecting members 4 is connected to each of the annular members 2,
One end 41 and the other end 42 which are arranged along the substantially cylindrical virtual cylindrical surface 5 formed by 3 and 3 and which are continuous with each of the annular members 2, 3 and 3 are vertical in the figure. Axial direction C
(The direction of expansion and contraction of the spring 1) is shifted in the radial direction so as not to overlap. Each of the elastic connecting members 4
The position of one end 41 and the other end 42 of each of the annular members 2,
In the illustrated embodiment, one end portion 41 that is continuous with the central small-diameter annular member 2 has the same angular position as that of the other end in the illustrated embodiment. The arm 41a on the one end 41 side is slightly shorter than the arm 42a on the other end side of the elastic connecting member 4. ing.

The upper and lower annular members 3 and 3 form an arc-shaped notch 33 on the inner peripheral side at a position overlapping with the curved portion 43 of the elastic connecting member 4 in the axial direction C. The notch 33 may be formed by bending the annular member 3 toward the outer periphery, or may be a through hole or a concave fitting portion depending on the shape of the annular member 3.

The spring 1 is integrally formed entirely of a synthetic resin material, and is basically formed using a mold. In the illustrated spring 1, the moldability is good due to the core divided vertically into two parts and the slide-type cavity divided into three parts in the figure. As the resin material used for the spring, a material having excellent bending strength and particularly strong in repeated bending stress is suitable. For example, a polypropylene-based, polyamide-based, or polyacetal-based resin is used.

When a compressive load P (equally distributed load) is applied to the spring 1 configured as described above in the axial direction C, each elastic connecting member 4 is tilted down as shown in FIG. The spring 1 is bent in a direction to narrow the space (d) of the character shape, and the spring 1 is compressed as a whole by an elastic deformation amount χ and becomes in an equilibrium state.

At this time, since the one end 41 and the other end 42 of the elastic connecting member 4 'are displaced in the radial direction as described above, they do not come into contact with each other. This allows the spring 1 to allow a larger amount of elastic deformation χ than a simple cylindrical spring in which the diameters of the annular members 2, 3, and 3 are equal. Noise generated due to contact with or interference with the reference numeral 42 can be prevented.

The upper and lower annular members 3, 3 are provided with cutouts 33, respectively.
The contact and interference between the annular members 3 and the curved portion 43 of the elastic connecting member 4 can be avoided, thereby also contributing to an increase in the amount of elastic deformation χ and prevention of noise.

Further, the positions of the one end 41 and the other end 42 of the elastic connecting member 4 are slightly shifted in the circumferential direction of the annular members 2, 3, and 3 so that the arm 41a on the one end 41 is slightly shorter. Therefore, at the time of elastic deformation, the elastic connecting member 4 has its curved portion 43
Are respectively displaced toward the upper and lower annular members 3, 3, so that the contact with the central annular member 2 having no cutout portion is suppressed. As described above, by appropriately setting the connection position, the shape, and the like of the elastic connecting member 4, the elastic deformation thereof is guided in a preferable specific direction, and the internal space of the spring 1 is effectively used, and Allowable elastic deformation 弾 性
Is preferably maximized.

The springs 1 constructed as described above are arranged such that a large number of the springs 1 are held between layers of a pair of upper and lower synthetic resin net-like elastic flat members (not shown). The upper and lower annular members 3 and 3 are fixed to the net-like elastic flat member and integrated to form a mattress spring made of only a synthetic resin material. A lightweight and quiet mattress having a different feeling from a conventional metal spring mattress can be formed by stacking elastic layers such as sheets and covering them with side lands.

In each of the above embodiments, the case where the spring 1 is formed by the three annular members 2, 3, 3 and the upper and lower elastic connecting members 4 connecting them has been described. The number of steps of the annular member and the elastic connecting member can be appropriately set, and can be a conical shape or the like in addition to the continuous shape. Furthermore, two or more springs 1 may be stacked and connected and used integrally by means such as adhesion, fusion or fitting. Further, the inverted U-shaped elastic connecting members 4 may be arranged as a pair of two members arranged in mirror symmetry with each other, or may be provided at three or more locations in the circumferential direction. Further, two or more portions having different patterns may be formed in the axial direction C of the spring by combining the arrangement patterns of two or more elastic connecting members.

[0018]

Since the spring of the present invention is configured as described above, the following effects can be obtained.

The whole is integrally formed of a synthetic resin material,
A plurality of annular members arranged at equal intervals and having the same axis and arranged in parallel, and an elastic connecting member for connecting the annular members to each other at a plurality of locations, the elastic connecting member includes:
In an inverted U-shaped spring arranged along a virtual cylindrical surface formed by each annular member and curved in the circumferential direction of the annular member, the diameter of the annular member is made different between adjacent annular members, Also, since one end and the other end of the elastic connecting member are provided shifted in the radial direction of the annular member so that they do not overlap in the direction of expansion and contraction of the spring,
The contact between one end and the other end of the elastic connecting member during elastic deformation is prevented, a large amount of elastic deformation can be tolerated compared to the size of the spring, and a metal coil spring conventionally used generally is used. , Much lighter than torsion bars, etc., the elasticity per weight of the synthetic resin material used is extremely large, there are no problems such as squeak noise and rust, etc. Furthermore, the manufacturing cost is low by using molded products. Because it can be suppressed, it can be expected to be widely used not only for mattresses but also for various elastic elements and cushioning elements.

The annular member has a notch which radially indents or is recessed or penetrated in the direction of expansion and contraction of the spring at a position where the annular member overlaps the curved portion of the elastic connecting member in the axial direction. Contact between the connecting member and the annular member,
Interference can be avoided, a large allowable elastic deformation can be ensured, and a quiet spring can be configured.

Further, the one end and the other end of the elastic connecting member are displaced from each other in the circumferential direction of the annular member, and the length of the arm on the one end side and the length of the arm on the other end side of the elastic connecting member are different. In addition, since the notch is formed in the annular member connected to the longer arm, the deformation of the elastic connecting member is guided to be deviated toward the annular member provided with the notch during the elastic deformation, and the internal space of the spring is formed. Is effectively used to secure a large amount of elastic deformation that can be tolerated and to suppress contact with the other annular member side, which is advantageous when it is difficult to form a notch in the annular member structurally. It is.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the spring of the present invention.

FIG. 2 is a front view showing an embodiment of the spring of the present invention.

FIG. 3 is a plan view showing an embodiment of the spring of the present invention.

FIG. 4 is a sectional view taken along line IV-IV ′ of FIG. 3;

FIG. 5 is a partially cutaway front view showing the elastically deformed state of the spring according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spring 2, 3 Annular member 4 Elastic connecting member 33 Notch 41 One end 41a, 42a Arm 42 Other end 43 Curved portion

Claims (3)

(57) [Claims] A plurality of annular members which are integrally formed of a synthetic resin material as a whole, are disposed at appropriate intervals, are arranged in parallel with the same axial center, and are elastically connecting the annular members to each other at a plurality of locations. A connecting member, wherein the elastic connecting member is disposed along a virtual cylindrical surface formed by each of the annular members, and is a U-shaped spring curved in the circumferential direction of the annular member. Is different between adjacent annular members, and one end and the other end of the elastic connecting member are provided to be shifted in the radial direction of the annular member so that they do not overlap in the direction of expansion and contraction of the spring. Features a spring. 2. The annular member has a cut-out portion which is radially indented or recessed or penetrates in the direction of expansion or contraction of the spring at a position axially overlapping the curved portion of the elastic connecting member adjacent thereto. The spring according to claim 1, wherein: 3. One end and the other end of the elastic connecting member are displaced in the circumferential direction of the annular member, and the length of the arm on the one end side and the length of the arm on the other end side of the elastic connecting member are different. 3. The spring according to claim 2, wherein a notch is formed in the annular member connected to the longer arm.