JPS5823528A - Production for coil spring coated with fluororesin - Google Patents

Abstract

PURPOSE:To form a thick fluororesin layer having optional dimensions to produce a coil spring superior in corrosion resistance, by molding a steel wire rod into a shape like a coil after coating the fluororesin on the steel wire rod and melt-fixing the fluororesin to terminals. CONSTITUTION:A wire rod cut to a required length is allowed to pass in a cylindrical mold 11 along the axis of the mold 11, and a softened fluororesin (a) is extruded from the side face of the mold into the mold to obtain a wire rod 1a coated with the fluororesin. This coated wire rod 1a is molded into a coil spring 1b by rollers 12, and this coil spring 1b is heated to remove the internal stress. Resin films 3 which consist of the same material as the coating layer and have a low melting point are inserted to end parts 2 of the coil spring 1b and are melt-fixed by heating, and thus, the wire rod is sealed so that the metal is not exposed in end parts 2.

Description

[Detailed Description of the Invention] ζO Inventory Co., Ltd. A method for manufacturing nine coil springs coated with fluororesin, which is used in corrosive prefectural gas tS as a member of chemical packaging, etc. ◎ Corrosive chemicals Medium gas KII
The springs that are used are those coated with fluororesin.The manufacturing method used previously is to form steel wire into a coil shape and disperse fluororesin (e.g. Teflon) into it. Ka! The method used was to crush it and apply it, or to make it into hot water like powder coating and spray it with Yuho resin, and then dry it for hooking.However, with this method, the coating thickness could only be 100 mm or less. Therefore, the corrosion resistance is often insufficient, and the method of spraying powder can cause pinholes to form and damage the steel wire. Also, since baking requires a temperature of 300 to 400°C, the steel wire tends to creep. In addition, with the method of inserting pre-formed nine coils into a fluororesin tip, the coating may be difficult to peel off and peel off due to long coils or small coils, and the inner wall of the tip may be damaged during insertion. It is easy to insert the thick O-cheap joints, and the inner diameter of the coil gets wrinkled.

The purpose of this invention is to provide a method for preparing %FH that overcomes the above-mentioned drawbacks.

To explain with an example, first, as shown in Figure 1, a wire rod cut to a required length along the central axis inside a cylindrical 1111, for example a piano wire, is passed through the side of the house and into the room. For example, in the case of a tetrafluoride resin, the fluororesin a, which has been softened by heating to about 300 C, is extruded and applied to the N4 surround of the wire to obtain the wire 1a coated with the fluororesin. Alternatively, the wire 1 may be inserted into the tube a' of the fluororesin layer to cover it.

Next, the coated steel wire 1& obtained in the above process is
The coil spring 1b is formed by a method similar to the row 212 shown in the figure, and is heated to remove the internal force. Since this temperature is about 250°C and is only for a short time, the coated fluororesin layer softens and changes in quality. There is no risk of such.

Next, the end portion 2 of the coil spring 1b coated with the above-mentioned fluororesin tube is coated with a material having the same quality as the coating layer and having a low melting point, such as a polymer of tetrafluoroethylene and hexafluoropyrene carbonate (FEP resin). A resin film 5 is inserted and heat-pressed to seal the end portion 2 so that no metal is exposed.

According to the above-mentioned manufacturing method according to the present invention, unlike the conventional method of inserting a formed coil material into a deep hole, it is possible to manufacture a coil of any size, and there is no possibility that wrinkles will occur on the inner diameter of the coil or that the coating It will not damage the inner wall of the layer. Since a thick fluororesin layer can be formed and the steel wire can be encapsulated without the presence of pinholes that would damage the metal wire, a coil spring with excellent corrosion resistance can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment showing the coating process of Honkyomei, FIG. 2 is a molding process, and FIG. 3 is a diagram showing the state of sealing the end of the coil.

Claims (1)

[Claims] t. A coating process for coating a steel wire with a fluororesin, a forming knee for forming the steel wire into a coil shape and removing internal stress, and further Y-
Manufacturing method 02 of a coil spring coated with a fluororesin, which consists of a sealing process of welding the fluororesin at the end of the etil and enclosing the steel wire, and extruding the heated and softened fluororesin around the circumference 11 of the steel wire. It has a coating step of applying it by
A method for manufacturing a nine-coil spring OII by coating a fluororesin according to claim 1. 5. A method for manufacturing a fluororesin-coated coil spring according to claim 1, which includes a coating step of inserting a steel wire into a fluororesin tube.