JP2764794B2 - Method of manufacturing spiral gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method of manufacturing a spiral gasket which is sandwiched between flanges of a pipe joint and used for sealing inside and outside of a pipe.

[0002]

2. Description of the Related Art Conventionally, a spiral gasket of this type includes:
A hoop material formed of a thin metal plate (thickness: 0.13 to 0.15 mm) having a corrugated cross section and a filler material formed mainly of inorganic fibers or the like are superimposed and spirally wound to form a coil. ing. In order to manufacture the spiral gasket having the above configuration, first, only the hoop material is wound around the winding piece for a few turns (hereinafter, referred to as an inner circumferential empty hoop material), and the corrugated convex of the inner circumferential empty hoop material is used. The rod-shaped electrode is pressed against the surface of the part in a pressurized state, and spot welding (two or three places) is performed to fix the hoop materials together. Then, the filler material is inserted, and the hoop material and the filler material are overlapped and rolled in the required number of times. At the end portion of the winding, only the hoop material is wrapped two or three times (hereinafter referred to as the outer circumferential hoop material), and the rod-shaped electrode is pressed on the surface of the corrugated convex portion of the outer circumferential hoop material in the same manner as described above. And fixing the hoop members by spot welding (at two or three places).

[0003]

In the above-mentioned method for manufacturing a spiral gasket, a rod-shaped electrode is used for spot welding of an empty hoop material, and the rod-shaped electrode is pressed against the corrugated convex surface of the hoop material in a pressurized state. Since the contact is performed by welding, the tip of the rod-shaped electrode is severely worn, and a polishing operation (one time / 30 to 40 minutes) is required to correct the deformation due to the wear. It is a problem.

[0004] Further, the rod-shaped electrode is connected to a welding location (two to three locations).
The workability is very poor because the application to the hoop material and the retreat are repeated each time. In addition, when the rod-shaped electrode is applied to the hoop material in a pressurized state, there is a problem that the hoop material is dented and deformed at the pressurized portion.

[0005]

An object of the present invention is to provide a method of manufacturing a spiral gasket which enables a spot welding workability to be greatly improved and improved in an inner circumferential empty hoop material and an outer circumferential empty hoop material during a spiral gasket manufacturing process. The main purpose is to provide

[0006]

According to the present invention, a metal hoop material having a corrugated cross section and a filler material are superposed and spirally wound, and the inner and outer hoop materials are fixed by spot welding. In a method of manufacturing a spiral gasket, a disk-shaped electrode body having a fitting groove on the outer peripheral end surface that matches the wave-shaped protrusion of the hoop material is used, and the fitting groove of the disk-shaped electrode body is changed to a wave-shaped protrusion of the hoop material. The gist is that spot welding is performed in a state of being fitted to the.

[0007]

When the disk-shaped electrode body is applied to the hoop material in a pressurized state, the fitting groove of the electrode body only presses the entire corrugated convex portion of the hoop material, and does not cause deformation wear.
In addition, in the state where the fitting groove is fitted to the corrugated convex portion of the hoop material, spot welding of a plurality of locations can be sequentially performed only by changing the relative rotation angle with the hoop material. It becomes possible.

[0008]

1 and 2 show an example of a disk-shaped electrode body used in a method of manufacturing a spiral gasket according to the present invention. In FIG. 1 and FIG. 2, A is a disk-shaped electrode body.
On the side of the board having the respective chamfered conical faces 1b, the two discs 1, 1
Are integrated by tightening bolts 3 passed through a plurality of screw holes provided in the insulating sheet material 2 and through holes provided in the insulating sheet material 2, and the outer circumference of the disk is formed by the conical surfaces 1 b of the disk portions 1. The end face has a V-shaped fitting groove 4 centered on the insulating sheet material 2. Examples of the material used for the disc portion 1 include alloys such as helium and copper, and examples of the material used for the insulating sheet material 2 include sheet materials made of fiber and rubber compounds, but are not limited thereto. Absent.

3 (A), 3 (B) and 3 (C) schematically show a process of fixing the spirally wound hoop members of the spiral gasket to each other by spot welding using the disk-shaped electrode body A having the above structure. . First, as shown in FIG. 3 (A), only the metal hoop material 5 having a corrugated cross section is wound around the winding piece 2 for two to three turns, and the disc-shaped electrode body A supported by the shaft 7 is fitted into its fitting groove 4. Is pressed into the state where it fits into the corrugated projection of the inner hoop material,
By applying a voltage between the disk portions 1 and 1, the inner circumferential hoop members are fixed to each other by spot welding. This spot welding is usually performed at a plurality of locations. In this case, it is only necessary to turn the winding piece 6 supporting the hoop material by a required angle, and apply a voltage at the rotation angle position, and the disc-shaped electrode body A pressed against the hoop material follows and turns. So
There is no need to separate it from the hoop material.

The above-described series of operations by spot welding, rotation of the winding piece, and spot welding can be automated by an external control circuit which operates by detecting each of the operations. FIG. 3B shows a welding fixing portion 8 by the spot welding.

After the completion of the spot welding of the inner hoop hoop material, the disk-shaped electrode body A is once separated from the hoop material.
As shown in (C), the filler material 9 is inserted and the hoop material 5 is inserted.
After winding the hoop material 5 around the end of winding two to three times at the end of the winding, the disk-shaped electrode body A is fitted with the fitting groove 4 in the same manner as described above. By applying a voltage between the disk portions 1 and 1 in a state where the hoop materials are fitted to the corrugated convex portions, the outer circumferential hoop members are fixed to each other by spot welding.

[0012]

As described above, according to the method for manufacturing a spiral gasket of the present invention, the following effects can be obtained. (1) In the disk-shaped electrode body used in the present invention, the fitting groove provided on the outer peripheral end face is fitted to the corrugated convex portion of the hoop material, and is held in a state of being pressed face-to-face, so that welding is performed. As a result, the electrode body side is not worn or deformed. Therefore, the work of correcting and polishing the electrode body becomes unnecessary, and the productivity can be greatly improved as compared with the conventional manufacturing method. (2) According to the use of the disk-shaped electrode body, it is not necessary to separate the electrode body from the hoop material side every spot welding. That is, since the spot welding and the winding of the hoop material can be performed at the same time, the production efficiency is remarkably improved as compared with the case where the spot welding is performed in the halt state of the hoop material winding in the conventional method. (3) Since the disk-shaped electrode body is pressurized in a state of being fitted to the corrugated convex portion of the hoop material as described above, the dent deformation does not occur in the pressurized portion of the hoop material.

[Brief description of the drawings]

FIG. 1 is a partially cut-away side view of a disk-shaped electrode body used in the present invention.

FIG. 2 is a partially cut plan view of a disk-shaped electrode body.

FIG. 3 is a manufacturing process diagram of a spiral gasket according to the present invention.

[Explanation of symbols]

 A disk-shaped electrode body 1 disk part 1a shaft hole 1b conical surface 2 insulating sheet material 3 bolt 4 fitting groove 5 hoop material 6 winding piece 7 axis 8 welding fixing part 9 filler material

Claims (3)

(57) [Claims] 1. A method for manufacturing a spiral gasket in which a metal hoop material having a corrugated cross section and a filler material are overlapped and spirally wound, and the inner circumferential empty hoop material and the outer circumferential empty hoop material are each fixed by spot welding. Using a disc-shaped electrode body having a fitting groove on the outer peripheral end surface that matches the corrugated convex portion of the hoop material, and spotting the disc-shaped electrode body with the fitting groove fitted into the corrugated convex portion of the hoop material. A method for producing a spiral gasket, comprising welding. 2. In a state where the fitting groove of the disc-shaped electrode body is fitted to the corrugated projection of the hoop material, the spot welding is continuously performed at the joint rotation angle position of the hoop material winding side and the electrode body. The method for producing a spiral gasket according to claim 1, which is performed. 3. A pair of discs made of a conductive material having a rotation axis are integrated with an electrically insulating sheet material as the disc-shaped electrode body, and the disc-shaped electrode body is formed on an outer peripheral end surface of the integrated disc. 4. The method for manufacturing a spiral gasket according to claim 3, wherein a substantially V-shaped fitting groove centering on an insulating sheet material is formed.