JPS6213837A - Polyacetal coiled spring - Google Patents

Abstract

PURPOSE:To obtain a coiled spring which is rust-proof, light and electrically insulating by using a polyoxymethylene ultradrawable wire rod having tensile elastic modulus more than a designated value. CONSTITUTION:Composition of polyoxymethylene ultradrawable wire rod is selected from polyacetal resin, homopolymer and copolymer. After the selected composite material having a tensile elastic modulus of 10Gpa or more is formed like a coil, it is heat-treated at a temperature of 130 deg.C or more and fixed to manufacture a coiled spring 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coil spring made of polyacetal and a method for manufacturing the same.

(Prior Art and Problems) It is well known that coil springs have been widely used in devices and machinery. These materials are mainly made of metal, especially iron-based metals, but they have drawbacks such as being easy to rust and being heavy.

(Means and effects for solving the problems) The present invention has been made as a result of various studies aimed at obtaining a coil spring that does not rust, is lightweight, and does not conduct constant LC electricity. Among the polyoxymethylene super-drawn wire rods produced by polyoxymethylene super-drawn technology (Japanese Patent Application No. 59-93737, etc.), the tensile modulus is 10 Gpa or more,
It was found that spring coils with a force of preferably 15 Gpm or more are plastically deformed, and that if the spring coil is formed into a coil shape at room temperature and then heat-set, it is possible to produce a spring coil that maintains its shape permanently, thus completing the present invention.

That is, the present invention provides a coil spring made of a polyoxymethylene super-drawn wire material with a tensile modulus of 1 ocpa or more, and a polyoxymethylene super-drawn wire material with a tensile modulus of 1 ocpa or more that is formed into a coil shape, and then heated at a temperature of 130° C. or more. This is a method for manufacturing coil springs that are fixed by heat treatment.

Of course, among spring characteristics, those related to deflection are related to the longitudinal elastic modulus of the material, but among plastic materials, there has never been a material with a large wire diameter and a large tensile elastic modulus that can be used to make a spring. According to the method of the present inventors, a polyoxymethylene superdrawn wire rod having a diameter of 0.3 W or more and a tensile elastic modulus of 10 Gpa or more can be obtained, and by using this, the object of the present invention can be achieved. . Regarding the manufacture of such wire rods, a special patent application was filed in 1973.
No. 9-93737, Japanese Patent Application No. 59-49338, etc.

The composition of the polyoxymethylene super-drawn wire used here is selected from polyacetal resin, homopolymer, and copolymer, and other additives may be added as necessary. Furthermore, the drawn wire may be coated with polyethylene, polyacetal, polyurethane, or other materials.

The cross-sectional shape of these super-drawn wires may be circular or rectangular or any other arbitrary shape, and may be hollow or thin-walled. In the case of a circular shape, the cross-sectional area may be 0.3Xφ or more, and may exceed 10%φ if necessary, and is not particularly limited.

In the present invention, these are collectively referred to as wire rods, and although these wire rods have the novel property of being able to be plastically deformed, they rebound and recover from weak stress, but the shape that is deformed by strong stress retains its original shape. keep. If this wire is now wound along the outer surface of a cylinder and the cylinder is removed, a coiled object will be obtained.

(Fig. 1) Even if left as is, it will not undergo large natural deformations, and even if it bends under a large load, it will return to its original shape.

However, in order to maintain the shape strictly, heat treatment fixation is preferable. Regarding heat treatment and fixation, conditions should be determined by observing the change in coil pitch, and by treatment at a temperature of 130°C or higher for less than 2 hours, the deformation should be suppressed to 7 t-1ts or less, and if necessary 0.5- or less. is possible. This treatment time is shorter as the temperature is higher than 130℃.
At 60°C, the goal is achieved within 2 minutes. Furthermore, such heat treatment significantly lowers the thermal shrinkage rate, and the
The heat shrinkage rate after 4 hours was x% or less.

(Effects) The coil spring of the present invention not only has sufficient spring characteristics, but also has features such as being lightweight (the fishing force of steel), rust-free, and electrically insulating. It has the potential to open up new fields of application.

(Example) The present invention will be further explained below with reference to Examples.

Example 1 Tenatsuku 3010 (Asahi Kasei Corporation) polyacetal,
A superstretched body with an outer diameter of 1.5W was manufactured using a dielectric selective heating method. The tensile strength of this material was 1, and the I Qpa % tensile modulus was 20 Gpa. Wrap this around a 10m diameter stainless steel pipe 10 times and pull it out of the pipe.
A spring coil is obtained, which stretches when a load is applied, and the load t
When the fc was removed, the urine temperature returned to normal. However, when I installed this product at night, the total length of the coil had increased by 10 inches. This coil was wound around the pipe and heat-set by leaving it open at 130° C. for 2 hours, and no dimensional change was observed even after cooling for more than 10 days. Also, similar processing is 1
Similar effects were observed even when heated at 60°C for 2 minutes.

Example 2 A wire rod with an outer diameter of 1 waφ and a tensile modulus of 40 Gpa made in the same manner as in Example 1 was used as a vibrator T/c 1G with a diameter of 12 mm.
I made a coil spring by winding it. When a 100f bell was attached to this spring, it expanded by about 9u.

A coil spring that exhibits similar deflection using piano wire has a wire diameter of 0.
．． Although it was obtained with a 7u wire, its weight was three times that of the acetal wire.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the method of the present invention, FIG. 1(A) is a perspective view of a state in which a wire is wound around a cylinder, and FIG. FIG. 3 is a perspective view with the cylinder removed. In the figure, 1 is a cylinder, and 2 is a coil spring made of super-drawn polyoxymethylene wire.

Claims (2)

[Claims] (1) Coil spring made of polyoxymethylene superdrawn wire with a tensile modulus of 10 Gpa or more (2) A method for manufacturing a coil spring, which involves forming a polyoxymethylene superdrawn wire rod with a tensile modulus of elasticity of 10 Gpa or more into a coil shape, and then fixing the coiled material by heat treatment at 130° C. or higher.