JPS61197829A - Plastic spring - Google Patents

Abstract

PURPOSE:To obtain excellent buffer device by using extensive polyoxymetylene having tensile elastic ratio of 5GPa or more as component of a spring. CONSTITUTION:A leaf spring 3 is produced by binding extensive bodies 1 of 25GPa of tensile elastic ratio made by extending extruded bar of polyacetar resin/with a dielectric heating extension device into boundle with metal bands 2. As polyacetar resin, polyoxymetylene extensive body is used. Therefore, as the material has excellent tensile strength, bending strength and tensile elastic ratio, and it is light and hard to be rusted, it can be used as a member of buffer device, buffer absorbing system effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a plastic spring, and more particularly to a plastic spring comprising stretched polyoxymethylene as a component. .

(Prior Art) Conventionally, springs have been frequently used as mechanical elements for purposes such as temporary storage of mechanical work, buffering, and vibration isolation. Steel is generally used as a component of such springs. However, steel has a specific gravity of 7.8, which is several times heavier than plastic, and it also has the disadvantage of being easily rusted and attacked by chemicals.

(Problems to be Solved by the Invention) The purpose of the present invention is to prevent rust from occurring or being attacked by chemicals.
Moreover, it is an object of the present invention to provide a plastic spring having excellent tensile strength, bending strength, and tensile modulus.

(Means for Solving the Problems) The present inventors researched various plastic materials as spring components and found that stretched polyoxymethylene was extremely excellent as a spring material, and arrived at the present invention. This is what I did.

The spring of the present invention has as a constituent element stretched polyoxymethylene having a tensile modulus of 5 GPa or more.

The stretched polyoxymethylene used in the present invention can be prepared, for example, by the method described in Kogyo Zazai Vol. 92, No. 4, P, 94-95;
It is a polyoxymethylene stretched body having a tensile modulus of 5 GPa or more and produced by the method disclosed in No. 3737 or other methods. The tensile modulus of 5GP3 or more of such a stretched body is extremely large compared to the tensile modulus of 0.350 Pa of a normal unstretched polyoxymethylene body, and the value of such a modulus is higher than that of other This value is far removed from that of plastics, indicating extremely high rigidity. Note that the bending elastic modulus, bending strength, and other material mechanical properties of the spring of the present invention have values corresponding to the above-mentioned tensile elastic modulus. It also has great characteristics.

The polyoxymethylene stretched product according to the present invention is usually obtained as a long product such as a rod shape or a sheet shape.

In the case of a rod shape, a round rod has a diameter of about 0.2 to 6 fl, and even if the cross section is other than circular, it can be obtained as a non-circular rod with a cross-sectional area corresponding to that of a round rod, and in the case of a sheet,
It can be obtained with a thickness of 0.1 m to 4 m and a width of 2 to 30 m. The dimensional stability of these stretched products, especially the superstretched products, is extremely high, and even after heat treatment, the heat shrinkage rate (for example, at 120°C for 60 minutes) is extremely small at 0.1% or less. Deformation and changes over time are also extremely small.

In order to manufacture a spring from such a stretched body, a composite spring such as a rod spring or a leaf spring can be manufactured by combining the above-mentioned rods and/or sheets, or by combining them with other materials. It can be manufactured by molding these materials alone or in combination into a suitable spring body shape such as a coil shape, a conical shape, a thinly wound shape, a bamboo strip shape, a dish shape, a stacked plate shape, etc. Other materials to be combined with the stretched polyoxymethylene of the present invention can be arbitrarily selected from metals, organic materials other than polyoxymethylene, composite materials, etc., but in particular, they can be used in combination with the unstretched polyoxymethylene molded product. is also valid.

(Effects of the Invention) A spring comprising a stretched polyoxymethylene body obtained by the present invention has a light specific gravity of about 1/6 that of steel, and a stretched polyoxymethylene body (including a superstretched body). ) has an elastic modulus of 10 to 60 GPa, which is lower than steel but close to aluminum, so it can be effectively used as an element in various mechanical devices. In addition, the spring of the present invention has excellent tensile strength, bending strength, and tensile modulus, is lightweight, does not rust, and has excellent chemical resistance. It can be used as a member of shock absorbers, shock absorbers, etc., for furniture, sports equipment (springboards, sticks, skis), etc.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

(Example) Example 1 An extruded round bar of polyacetal resin (manufactured by Asahi Kasei Corporation, Tenafuku 3010) was stretched using a dielectric heating stretching device, with a diameter of 2.2 mm and a tensile strength of 120 kg/m+.
v? , the stretched body 1 with a tensile modulus of 25 GPa was
As shown in the figure and FIG. 2, a leaf spring 3 and a bar spring 4 were created by tightly bundling them with a metal band 2. The obtained bar spring exhibited excellent bending resistance', and its bending resistance value was almost equivalent to the value calculated by material mechanics.

Example 2 An array of round bars made of the same polyacetal resin as used in Example 1 was sandwiched between upper and lower iron plates or extruded polyacetal plates 6, and these were tightly bundled with a metal band 2 to create a leaf spring 5. The bending resistance value of this leaf spring also showed an excellent value.

Example 3 In Example 2, synthetic rubber adhesive (natural rubber adhesive)
A leaf spring was produced in the same manner as in Example 2, except that each constituent material was fixed using the following method. The bending resistance value of this product was excellent as in Example 2, and the round bars were well bound together by using the adhesive.

Example 4 A sheet with a tensile modulus of elasticity of 20 GPa and a thickness of 0.2 nm was produced by stretching a 0.8 nm thick sheet made using polyacecool resin (manufactured by Asahi Kasei Corporation, Tenac 3010). did. As shown in FIG. 4, five of these 1°A sheets were stacked one on top of the other and tightly bound with a silkworm band 2 to produce a leaf spring 7 of the present invention.

This leaf spring had extremely high bending resistance.

[Brief explanation of drawings]

1, 2, 3, and 4 are perspective views of springs each showing an embodiment of the present invention. 1...Polyoxymethylene stretched body (rod), lA...
Polyoxymethylene stretched body (sheet), 2... Metal band, 3.5.7... Leaf spring, 4... Rod spring, 6...
...Flat plate. Agent Patent Attorney Takenaga Kawakita Figure 1 Figure 4

Claims (1)

[Claims] (1) A plastic spring whose constituent element is stretched polyoxymethylene having a tensile modulus of 5 GPa or more.