JPH0220635A - Anticorrosive coil spring and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a coil spring excellent in mechanical properties and anticorrosion by forming wire coated with synthetic resin coat in a coil shape and mounting synthetic resin caps covering both end faces of the formed wire. CONSTITUTION:A long-sized wire 1 of hard steel wire etc., having a coat 2 such as fluororesin PFA is used as a coil wire 1 and this wire 1 is obtained by coating its outer circumference of the wire 1 with fused resin through the use of a crosshead 5, etc., with tight adhesion. Then, the wire is folded by a known equipment in a coil shape and cut to a desired dimensional length L to obtain individual coil springs 6. The ends 1b, 1b of the wire are covered with caps 3, 3 each of which is made of the same resin PFA, etc., as the coat 2 and has an open recessed part 4 on one end, to cover both end faces 1a, 1a. After the outside fitted, heat sealed 11 is brought into contact with the inner end side of the cap 3 to be thermally deposited. By this method, it is possible to obtain an anticorrosive coil spring excellent in mechanical properties and free from pin holes, peeling, cracks, etc.

Description

[Detailed description of the invention] (Industrial application field) The present invention is rust prevention, corrosion resistance against acid or alkali.

Alternatively, the present invention relates to a corrosion-resistant coil spring that can suitably provide chemical resistance, etc., and a method for manufacturing the same.

(Prior Art) As is well known, in the field of fluid equipment, coil springs are often used by directly immersing them in fluid.
Under such usage conditions, it is necessary for the coil spring to have corrosion resistance.

Therefore, as a conventional method, for example, the coil spring is made of stainless steel, or, as shown in FIG. 5, a flexible synthetic resin tube 12 is fitted into a coiled wire 1e. It had been.

(Problem to be Solved by the Invention) However, in the former conventional means, stainless steel is softer than spring steel commonly used for this type of coil spring, and therefore has inferior mechanical properties as a coil spring. For example, long-term use can cause problems such as a significant drop in elasticity. Further, even stainless steel is not universal, and its corrosion resistance is not always satisfactory under specific usage conditions.

On the other hand, in the latter method, the work of fitting the synthetic grease-resistant tube 12 into the spiral wire 1e is extremely complicated, and this poses a fatal problem. In particular, for tension springs in which there is no gap 1 between the wire rods, the work of fitting the tube 12 is even more difficult, and it has been said that it is extremely difficult to put the tube 12 into practical use. This method of fitting cannot be applied because the tube 12 would break when the wire 1e was bent into a coil shape.

In addition, in the latter type of thin-walled tube 12 that is malleable, pinholes are likely to occur during its manufacturing process and during use, and not only can complete coverage of the wire 1e not be expected, but both end surfaces 1a, 1a of the wire ple Since the tube 12 does not cover the area 1al 1
This method has disadvantages such as rusting and corrosion of the wire rod 1e from a to 1e. Therefore, this conventional wire rod 1e is inferior in terms of complete coverage and has the disadvantage that it cannot provide excellent corrosion resistance.

Therefore, it is an object of the present invention to make it possible to use a material with excellent mechanical properties as a wire rod, and to provide a coil spring with excellent corrosion resistance using inexpensive and simple working means.

(Means for Solving the Problems) The present invention is configured to solve the above-mentioned conventional problems by coating the outer surface of the wire with resin and appropriately coating the ends of the wire.

That is, in the present invention, a resin-coated wire 1 with a synthetic resin coating layer 2 adhered to the outer surface is formed into a coil shape,
Moreover, it is a corrosion-resistant coil spring in which synthetic resin caps 3, 3 are fitted to both ends of the coiled wire 1 to cover the end surfaces 1a, 1a of the wire 1.

Further, the present invention provides a method of forming a resin-coated long wire 1 with a synthetic resin coating layer 2 on its outer surface into a coil shape, and then cutting the coiled wire 1 into a predetermined size. Thereafter, a synthetic resin cap 3.3 is fitted over the cut ends 1b, 1b of the wire 1 to cover the cut end surfaces 1a+1a of the coiled wire 1, and the cap 3.3 is attached to the coating layer 2 of the wire 1. This is a method of manufacturing a corrosion-resistant coil spring by thermally welding the spring to the coil spring.

(Function) In the coil spring having the above-mentioned former configuration, the entire surface of the wire 1, including both end surfaces of the jar 1a, is covered with the coating layer 2 and the cap 3.3, so the coil spring is immersed in the chemical solution. Even if the wire rod 1 is used for dipping, the wire rod 1 will not come into contact with the chemical solution. Therefore, even a material without corrosion resistance can be used for the wire rod 1, and a material with excellent mechanical properties such as spring steel can be used as appropriate. In addition, the synthetic resin coating layer 2 on the outer surface of the wire 1 can be made in a state where pinholes, cracks, peeling, etc. are difficult to occur, and when the resin-coated wire 1 is bent into a coil shape, This can suitably prevent the wire rod 1 from being exposed to the outside due to severe damage. Furthermore, the coating layer 2 can be made to be resistant to peeling or cracking due to expansion and contraction of the coil spring, and the coating of the wire rod 1 can be coated with excellent reliability.

Furthermore, in the method for manufacturing a coil spring having the latter configuration, the former coil spring can be appropriately manufactured, and in particular, the cap 3.3 fitted over both ends 1b, 1b of the wire 1 is attached to the coating layer 2 of the wire 1. The cap 3 is bonded by heat welding.
．． 3 and the coating layer 2 can be closed, thereby preventing undue fluid intrusion into the end surface 1a of the wire 1.

Further, the heat welding prevents the cap 3.3 from coming off, and the cap 3.3 can be securely attached.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

To explain an example of the method for manufacturing a corrosion-resistant coil spring according to the present invention, first, as shown in FIG. A long wire 1 such as a coated hard steel wire is used, and the coated wire 1 is manufactured by continuously and tightly coating the outer periphery of the wire 1 with molten resin using a crosshead 5 or the like as shown in the figure. It can be easily obtained by a similar method. In addition, in the resin coating means, the coating layer 2
A high-quality coating layer can be obtained by eliminating the possibility of pinholes or the like occurring in the wire rod 1, and the adhesion to the wire rod 1 is strong, making it extremely difficult for peeling or cracking to occur.

Therefore, the wire 1 can be bent into a coil shape using a known device as shown in FIG. 3(A) without causing any cracks or the like in the coating layer 2. Moreover, the bending of the wire rod 1 can of course be applied to both types of tension springs and compression springs.

Next, the elongated coil is cut into desired dimensions and lengths as shown in FIG. 2B to obtain individual coil springs 6a. however,
Cut end surfaces tar of both ends of the wire rod 1 of the coil spring 6a
1a is in an exposed state where the covering layer 2 is not present.

After that, an open recess 4 is formed at one end of the wire 1 at both ends 1b and Ib, for example, made of resin PFA similar to the coating layer 2.
The caps 3, 3 having the
It covers both end faces 1al and 1a.

Note that, before performing the external fitting work of the caps 3, 3, if both ends 1b, Ib of the wire rod 1 are bent in the axial length direction of the coil spring to form a straight line, the external fitting work will be very easy. becomes.

After the external fitting operation, the heat sealer 11 is brought into contact with the inner end side of each cap 3 as shown in FIG.
Heat weld to. As a result, the cap 3 and the wire 1 can be brought into close contact with each other, eliminating the gap between them, and the cap 3 can also be prevented from being accidentally pulled out, thereby improving the corrosion resistance of the structure as shown in FIG. Thus, a coil spring 6 of 1 is obtained.

The corrosion-resistant coil spring 6 obtained by the above-mentioned work process is, for example, a fluid flow path 8 formed in the casing 7 as shown in FIG.
In the Chatsuki valve 10 which opens and closes with the ball 9,
The coil spring 6 is used as appropriate for pressing the ball 9. Even under these conditions of use, the surface and both ends of the wire 1 of the coil spring 6 are covered with the synthetic resin coating layer 2 and the cap 3.
It doesn't seem to rust. Furthermore, since the coating layer 2 and caps 3, 3 made of PFA or the like have corrosion resistance against acids and alkalis, the chatty valve 10 can also be suitably used as a liquid transport path for chemical liquids.

Furthermore, even if the coil spring is repeatedly expanded and contracted, the coating layer 2 does not easily peel off or crack, and its service life is considerably extended.

Incidentally, in the present invention, the specific materials of the coating layer 2 and the cap 3 are not limited to those in the above embodiments.

These specific materials may be appropriately determined depending on the specific usage conditions of the coil spring, and various other compositions (phase-resistant materials are also applicable. may be made of different materials.

Furthermore, regardless of the specific shape and dimensions of the cap 3 according to the present invention, the cap must be shaped like a cap that can be fitted onto the end 1b of the wire 1 and can cover the end surface 1a of the wire 1 by the external fitting. It is acceptable as long as it is formed.

Furthermore, the specific structure of the wire 1 is not limited as in the above embodiments, and any wire may be used as long as the outer surface is coated with a synthetic resin coating layer to provide equal phase resistance. As the material, various wire rods other than hard steel wire can be used, and the wire diameter, length, etc. are not limited at all.

As described above, the specific structure of each part of the corrosion-resistant coil spring according to the present invention can be freely modified within the scope of the present invention.

Furthermore, the manufacturing method according to the present invention is not limited to the above-mentioned embodiments, and all work steps such as providing a coating layer on the outer surface of the wire, forming the wire into a coil shape, and fitting the cap onto the outside are all The design can be changed as desired within the intended scope of the present invention. Note that the means for manufacturing the coil spring according to the present invention is not limited to the manufacturing method according to the present invention.

In addition, the present invention is not limited to coil springs that are used by being immersed in a liquid, but may also be used as a coil spring with anti-corrosion properties other than in a liquid. Use.

There is no question as to how it is used.

(Effects of the Invention) As shown on the board, the present invention forms a wire rod whose outer surface is coated with resin into a coil shape, and covers both end surfaces with caps, thereby suitably covering the entire surface of the coiled wire rod. Since the coil wire material has corrosion resistance, spring steel can be appropriately used as the coil wire material, and the mechanical properties of the spring can be improved. There is no longer any need for complicated work, and manufacturing can now be done by simply forming a resin-coated wire into a coil shape and then fitting caps on both ends, making the manufacturing cost much lower than before. This has resulted in the special effect of being able to be made at low cost.

Moreover, since the present invention covers the entire outer surface and end face of the wire with a synthetic resin coating layer and a cap, not only can the corrosion resistance of the wire be improved, but also the coating layer has pinholes and the like. Because it does not easily peel or crack due to bending when forming the wire into a coil or expansion and contraction when using a coil spring, the wire can be sufficiently protected and its service life can be extended. There are advantages that can be achieved.

In addition, the manufacturing method according to the present invention can suitably manufacture the corrosion-resistant coil spring with the above-mentioned excellent characteristics, and also heat-welds the cap fitted over the end of the wire to the coating layer on the outer surface of the wire. The cap can be securely fixed, and the gap between the cap and the coating layer can be closed, and liquid can be reliably prevented from penetrating into the end surface of the wire. This provides the advantage of more complete protection.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional main part front view showing an embodiment of a coil spring according to the present invention. Figures 2 and 3 show an example of manufacturing work for a coil spring according to the present invention, Figure 2 is a cross-sectional view showing a resin-coated wire rod and its manufacturing process, and Figure 3 (a) shows a coiled wire rod. Figure (b) is a front view of the main part of the molded state, and the same figure (b) is a partial cross-sectional front view of the main part of the process of fitting the cap onto the coil spring.
C) is a cross-sectional front view of the main part of the process of heat-welding the cap. FIG. 4 is a sectional view showing an example of how a coil spring is used. FIG. 5 shows a conventional example, in which (a) is a sectional view of the main part, and (b) is a perspective view of the main part. 1...Wire rod 2...Coating layer 3...Cap Applicant Nihon Feeder Kogyo Co., Ltd. Agent Patent attorney Noboru Fujimoto Figure 1

Claims (1)

[Scope of Claims] 1. A wire rod 1 whose outer surface is coated with a synthetic resin coating layer 2 is formed into a coil shape, and both ends 1b, 1b of the wire rod 1 formed into a coil shape. A corrosion-resistant coil spring characterized in that synthetic resin caps 3, 3 are fitted to cover the end faces 1a, 1a of the wire 1. 2. After forming a resin-coated long wire 1 with a synthetic resin coating layer 2 on the outer surface, the coiled wire 1 is cut into a predetermined size, and then the coiled wire 1 is cut into a predetermined size. Synthetic resin caps 3, 3 are fitted onto the cut ends 1b, 1b of the wire 1 to cover the cut end surfaces 1a, 1a of the wire 1, and the caps 3, 3 are heat welded to the coating layer 2 of the wire 1. A method for manufacturing a corrosion-resistant coil spring, characterized by: