JPH0144227Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a welding gas seal device, and in particular to a welding gas that facilitates X-ray flaw detection and saves labor in welding work. This invention relates to a sealing device.

[Technical background and problems of the invention]

Generally, when the ends of tubes are butted together and joined by inert gas arc welding such as TIG or MIG, the tubes are filled with sealing gas to form the initial layer of the weld. It is necessary to keep it. Therefore, during welding, a gas sealing device is inserted into the butted tubes across the welded portion to form a gas sealing layer there.

The above-mentioned gas seal device includes a shielding member that is inserted into the ends of the respective pipe bodies to be butted together to form a gas sealing layer spanning the welded portion, and a shielding member that traverses the gas sealing layer. It mainly consists of a connecting member that connects the pipes, and a gas supply device that injects inert gas into the gas seal layer that has been partitioned. was.

On the other hand, welded parts that need to be joined by inert gas arc welding such as TIG or MIG are always subjected to a flaw detection inspection using radiography afterwards. However, since the connecting member of the gas seal device intersects with the weld line of the welded part, if radiography is performed while it is inserted into the tube, the connecting member will be imaged on the film, which could be considered a welding defect. There was a problem with being judged.

For this reason, in the past, radiographs were taken with the gas seal device inserted, knowing that the radiation film would be wasted, and after confirming that there were no welding defects, the gas seal device was removed and radiographs were taken again normally. was going there. Another method involves removing the gas seal device once during radiography, and if a defect is found, reinstalling the gas seal device and redoing the welding process, which is a time-consuming process.

[Purpose of invention]

The present invention was devised in order to improve the problem as much as possible in view of the above-mentioned problems, and its purpose is to eliminate the waste of radiation film during flaw detection and repair of welding defects. An object of the present invention is to provide a welding gas seal device that can save labor during work.

[Summary of the idea]

In this invention, when the ends of the tubes are butted against each other and joined by inert gas arc welding such as TIG or MIG, a gas seal layer is added over the welded part to be joined to the ends of the tubes that are butted together. In the sealing device for forming a gas sealing device, shielding members are inserted into the ends of the butted pipe bodies and facing each other to form a gas sealing layer at the welded portion, and a carbon fiber material is molded between these shielding members. and a connecting member provided so as to cross the gas seal layer and connect each other, thereby preventing the connecting member from being imaged on the film during radiography, thereby achieving the above purpose. It is something to be achieved.

[Example of idea]

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows TIG and MIG
Pipe body 1 joined by inert gas arc welding such as
a, 1b, the respective end portions 3a, 3b straddle the welded portion 2 to form a gas sealing layer there.
1 shows a first embodiment of a welding gas seal device 4 that is inserted into the interior.

As shown in the figure, each pipe body 1 to be joined
A shielding member 7 is inserted into the end portions 3a, 3b of the pipes 5a, 1b so as to face each other, and shields the respective pipes 5a, 5b to define a gas seal chamber 6 therein.
a and 7b are provided. These shielding members 7a, 7b
are shielding plates 8a and 8b formed of plywood or tin plate, and sealing members 9 provided on the circumferential sides of these shielding plates 8a and 8b to seal the gap between the inner walls of the tubes 1a and 1b; 9, and flat rubber is used for the seal members 9a and 9b in the illustrated example.

A connecting member 10 is provided between these shielding members 7a and 7b so as to connect the shielding members 7a and 7b across the gas seal chamber 6 (gas seal layer) that they partition. The illustrated connecting member 10 represents a cable 11 for pulling out the gas seal device 4 when it is removed, and this cable 11 is connected to the shielding members 7a, 7b by connecting fittings 12, 12.

Further, one of the shielding members 7b is provided with a gas supply device 13 for supplying a welding shield gas such as argon into the gas seal chamber 6. In the illustrated gas supply device 13, 14 is a short pipe for discharging welding shield gas, 15 is a flexible pipe such as a vinyl hose, and 16 is a valve for shutting off or opening the supply of welding gas. These are connected to a shielding gas supply source (not shown).

By the way, the feature of the present invention is that carbon fiber material is used for the above-mentioned connecting member 10. That is, in the gas seal device 4, the connecting member 10 that intersects with the weld line 17 of the welded portion 2 is formed of carbon fiber, so that the gas seal device 4 can be easily removed during flaw detection after welding work is completed. Even if the welded portion 2 is radiographed while inserted, the connecting member 10 is configured not to be imaged on the radiation film.

Next, the operation of this embodiment will be described.

First, when the ends 3a and 3b of the tube bodies 1a and 1b are butted together and joined by inert gas arc welding, in order to form the initial layer of the welded joint, weld them over the weld line 17 of the welded part 2. A gas seal device 4 for forming a gas seal layer is inserted into the tubes 1a and 1b.

The gas seal device 4 has its shielding members 7a and 7b.
are inserted into the ends 3a, 3b of the respective pipe bodies 1a, 1b to shield the pipes 5a, 5b,
A gas seal chamber 6 spanning the welded portion 2 is defined here. A shield gas such as argon gas is supplied to the gas seal chamber 6 from a welding shield gas supply device 13. When this shielding gas fills the gas seal chamber 6 and begins to be released from the welding line 17 of the welding part 2, the ends 3a and 3b of the pipe bodies 1a and 1b to be joined are moved toward the outer periphery while releasing the shielding gas. Then, the first layer is formed by joining by inert gas arc welding such as TIG or MIG.

After welding work is completed, gas seal device 4
The welded part 2 is radiographed along the welding line 17 while the welded part 2 is inserted, and a flaw detection inspection is performed. At this time,
Since the connecting member 10 of the gas seal device 4 is made of carbon fiber, it is not imaged by a radiation film. Therefore, the image of the connecting member 10 is not determined to be a welding defect, and the radiation film is prevented from being wasted and the number of steps required for imaging can be reduced. Furthermore, even if a defect is discovered, the gas seal device 4 remains inserted, so repair work can be carried out immediately, resulting in labor savings.

What is shown in FIG. 2 shows a gas seal device 4 of a second embodiment. This second embodiment differs from the first embodiment described above in that the shielding members 21a, 21
The reason is that b is an air-filled type. As shown in the figure, each shielding member 21a, 21b has two shielding plates 22a, 22a and 22b, 22b arranged side by side with a predetermined distance maintained by shielding plate fasteners 23, 23... A tire-shaped or tube-shaped rubber sealing member 24 that is open radially inward on the circumferential side is provided and formed, and the shielding member 21
Air chambers 25 are defined within a and 21b.
An air supply/discharge device 26 for supplying and discharging air into the air chambers 25, 25 is connected to the shielding members 21a, 21b, and the sealing members 24, 24 are expanded by the supplied air. shielding plate 2
2a, 22a, 22b, 22b and tube bodies 1a, 1b
It is configured to form a seal between the inner wall and the inner wall.

The air supply/discharge device 26 includes a valve 27 that blocks or opens a conduit from an air supply/discharge source (not shown).
and a perforated short pipe 28 that passes through the shielding members 21a and 21b and supplies and discharges air into the air chamber 25 therein.
and combustible pipes 29, 30, etc. that connect them, and the ends 3 of each tube body 1a, 1b.
Shielding members 21a and 21b inserted into a and 3b
The combustible pipe 30 that connects the gas seal device 4 intersects the weld line 17 of the weld portion 2 and serves as the connecting member 10 of the gas seal device 4 that crosses the gas seal chamber 6 .

Therefore, in this second embodiment, the combustible pipe 30 connecting the shielding members 21a and 21b is also molded from carbon fiber material.

The other main components of the second embodiment are substantially the same as those of the first embodiment described above, and in the figure, reference numeral 11 indicates connecting members 10 and 13, which serve as cables for pulling out the gas seal device when it is removed, are welded. This is a supply device for shielding gas. Further, its operation and effect are also similar to those of the first embodiment described above.

[Effect of idea]

In summary, the present invention provides the following excellent effects.

(1) In a gas seal device that is inserted across the welded part into pipes that are butted against each other and joined by inert gas arc welding such as TIG or MIG, the gas seal device is inserted between the shielding members by crossing the weld line of the welding part. By forming the connecting member with carbon fiber material, it is possible to prevent the connecting member from being imaged on the radiation film even if radiography is performed with the gas seal device inserted during flaw detection after welding work is completed. .

(2) Therefore, the image of the connecting member is not determined to be a welding defect, making it possible to reduce the number of images to be taken and the amount of radiation film consumed, as well as reducing the number of steps for taking images.

(3) Furthermore, even if a welding defect is discovered by radiography, the gas seal device remains inserted, so repair work can be carried out immediately, thereby saving labor.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing a first embodiment of a welding gas seal device according to the present invention, and FIG. 2 is a schematic side sectional view showing a second embodiment. In the figure, 1a and 1b are tube bodies, 2 is a welded part, 3a,
3b is an end, 6 is a gas seal chamber forming a gas seal layer, 7a, 7b, 21a, 21b are shielding members, 10 is a connecting member, 11 is a cable as a connecting member, 30 is a flexible member as a connecting member It's a pipe.

Claims (1)

[Scope of utility model registration request] When welding the ends of the tubes against each other,
In a sealing device that forms a gas seal layer across the welded parts joined to the ends of the pipe bodies to be butted, the welded parts are inserted into the ends of the pipe bodies to be butted and face each other. A shielding member forming a gas seal layer on the gas sealing layer, and a connecting member molded from a carbon fiber material and provided between these shielding members so as to cross the gas sealing layer and connect each other. Gas seal device for welding.