JPH0150500B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an apparatus for manufacturing unit springs used in pinerests and the like.

[Technical background of the invention and its problems]

For example, in some mattresses, a unit spring made of a number of coil springs continuously molded is used instead of a single coil spring. There are various types of unit springs, one of which is known as shown in Japanese Utility Model Publication No. 53-35573. As is clear from FIG. 3, this unit spring is constructed by forming a large number of coil springs from one wire at predetermined intervals via U-shaped connecting rods (connections).
It is formed by intertwining parts of adjacent coil springs with each other. Such a unit spring is not only easy to assemble when used in a mattress or the like, but also has the advantage that each coil spring is difficult to elastically deform on its own, thereby preventing local collapse.

However, in the conventional unit spring manufacturing apparatus, the wire rod was simply bent as described above. As a result, each coil spring of the unit spring undergoes work hardening, resulting in drawbacks such as easy fatigue. In order to eliminate such defects, it is conceivable to heat-treat the unit spring manufactured by the above-mentioned manufacturing apparatus in, for example, an electric furnace. However, when heat treatment is performed using an electric furnace, not only is the thermal efficiency low, but the process of manufacturing the unit spring using the manufacturing apparatus described above and the heat treatment process are discontinuous, resulting in problems such as a decrease in workability.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a unit spring manufacturing apparatus that is capable of heat-treating the unit spring in succession with the process of manufacturing the unit spring.

[Summary of the invention]

In the present invention, a plurality of coil springs are formed from a single wire rod in a first forming section, and a portion of adjacent coil springs are entwined with each other in a second forming section, and then the above-mentioned unit springs are assembled in a heat treatment section. This is a unit spring manufacturing device that performs heat treatment by heating with electricity.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. The unit spring manufacturing apparatus shown in FIG. 1 includes a base 1. The unit spring manufacturing apparatus shown in FIG. A pedestal 2 is erected on the base 1, and a first molded part 3 is provided on the pedestal 2. A wire rod 5 wound around a rotatable drum 4 is supplied to the first forming section 3 by a feeding mechanism 6 provided on the base 1. In the first molding section 3, an unfinished unit spring 7 shown in FIG. 4 is molded by well-known means. This unit spring 7 has a U-shaped connecting rod portion 9 that connects a large number of coil springs 8 to the wire 5.
The holes are formed at predetermined intervals through the holes.

The unfinished unit spring 7 formed in the first forming section 3 is supplied to the second forming section 10. This second molded part 10 is provided in the middle of the conveyance path 11 whose one end is connected to the pedestal 2, and here, the helical part of each adjacent coil spring 8 of the unfinished unit spring 7 is formed by known means. The unit spring 12 is formed by intertwining the parts with each other as shown in FIG.

After the second molding section 10, a heat treatment section 13 is provided.
is provided. The heat treatment section 13 includes a first heating section 15 and a second heating section 16, each of which has a pair of cylinders 14 facing each other along the width direction of the conveyance path 11. The first heating section 15 is arranged so that one cylinder 14 is shifted from the other cylinder 14 by one pitch of the coil springs 8 arranged in a row in the conveying direction of the unit springs 12 shown by the arrow in FIG. has been done. Further, the second heating section 16 has one cylinder 14 connected to the other cylinder 14.
The unit spring 12 is arranged to be shifted by one pitch of the coil spring 8 in the direction opposite to the conveyance direction of the unit spring 12. An electrode plate 18 is attached to the rod 17 of each cylinder 14, which is electrically connected to a power source (not shown). These electrode plates 18 are connected to the cylinder 14
When the rods 17 are urged in the projecting direction, they come into contact with clamping plates 19 arranged along the width direction of the conveyance path 11, respectively. A connecting rod portion 9 continuous to both ends of each coil spring 8 of the unit spring 12 is held between the holding plate 19 and the electrode plate 18, so that each coil spring 8 is heated by electrical current. ing. That is, in the state shown in FIG.
5 is activated. Then, this pair of cylinders 14
Since the current flows through the shortest distance between the electrode plate 18 and the clamping plate 19,
A coil spring indicated by 8a in the figure is heated by energization.
Next, when the first heating section 15 is deactivated, the unit spring 12 is advanced one pitch, and then the second heating section 16 is activated. Then, the coil spring shown as 8b in the figure is similarly heated by electricity.

In the unit spring 12, the conveyance of the unit spring 12 is stopped for a predetermined time, for example, about 0.5 seconds when the helical portions of the adjacent coil springs 8 are entangled with each other by the second molding section 10. The first and second heating sections 15 and 16 are arranged to operate alternately. In addition, the first and second heating parts 15 and 16 heat each coil spring 8 at about 320°C.
Heat for about 0.3 seconds.

A winding drum 20 is rotatably provided at the other end of the conveyance path 11, and is adapted to wind up the unit spring 12 that has been heat treated in the heat treatment section 13.

According to the manufacturing apparatus configured in this way, the first
The unit spring 7 formed by the forming part 3 and the second forming part 10 is heated by the heat treatment part 13 provided after the second forming part 10, so that each coil spring 8 is
is heated with electricity and heat treated. Therefore, by bending the wire 5, the work hardening that occurs in each coil spring 8 is removed, so that the coil springs 8 have elasticity that prevents them from buckling. Furthermore, after the unit spring 7 is molded by the second molding section 10, it is heat-treated in succession to this step. Therefore, the heat treatment of the unit spring 7 can be carried out efficiently. Furthermore, the heat treatment section 13 has a simple structure because the electrode plate 18 and the clamping plate 19 simply clamp the connecting rod part 9 of the unit spring 7.

〔Effect of the invention〕

As described above, the present invention forms a large number of coil springs at predetermined intervals by the first molding part and the second molding part through the connecting rod part, and also connects some of the adjacent coil springs to each other. After the entangled spring was molded, the coil spring was heat-treated by being electrically heated in a first heating part and a second heating part of a heat treatment part provided after the second molding part. Therefore, since the work hardening that accompanies the forming of the coil springs is removed, these coil springs are less prone to fatigue and the performance of the unit spring is improved. Further, since the heat treatment of the unit spring by the heat treatment section can be performed continuously with the molding of the unit spring, the work efficiency is good, and since each coil spring is heated by electricity, the structure is simple. Further, the heat treatment section includes a first heating section and a second heating section, and each heating section includes a pair of cylinders each provided with an electrode plate, and a clamping member that holds the coil spring section between the electrode plates. This makes it possible to heat-treat each coil spring, which consists of a plate and is continuously formed as a unit spring, by each heating section alternately, that is, while continuously forming the unit spring. Also, the heat treatment of the unit spring can be carried out efficiently and reliably.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic configuration diagram of the entire apparatus, Fig. 2 is a plan view of the heat treatment section, Fig. 3 is a sectional view taken along the line of Fig. 2, and Fig. 4 The figure is a perspective view of an unfinished unit spring molded by the first molding part, and FIG. 5 is a perspective view of the unit spring molded by the second molding part. 3...First molded part, 5...Wire rod, 8...Coil spring, 9...Connection rod part, 10...Second molded part, 12...Unit spring, 13...Heat treatment part.

Claims (1)

[Claims] 1. A first molded part in which a large number of coil springs are formed from one wire at predetermined intervals through a connecting rod part, and the coil springs are arranged in a row so that their axes are parallel to each other, and A unit spring manufacturing apparatus comprising: a second molding section for forming a unit spring by entangling parts of coil springs with each other; and a heat treatment section for heating the unit spring formed by the second molding section with electricity. In the above, the heat treatment section includes a first heating section and a second heating section that are arranged in sequence along the conveying direction of the unit spring, and each heating section is perpendicular to the conveying direction of the unit spring. It is composed of a pair of cylinders arranged facing each other in the direction, an electrode plate provided on the rod of each cylinder, and a clamping plate that clamps the end of the coil spring of the unit spring with each electrode plate. A unit spring manufacturing device characterized by: