JPS59223164A - Continuous welding of long metallic tube seam and arc torch for tig welding of seam part - Google Patents

Abstract

PURPOSE:To obtain a long tube excellent in airtightness and more than 10,000m in length in a process that makes a long tube by TIG welding seam parts made by forming a metallic tape to cylindrical form continuously, by pushing down the electrode of a welding torch according to consumption. CONSTITUTION:A metallic tube 3 made by rounding a relatively thin metallic tape having incorporated wire 1 such as an optical fiber cable etc. is moved in the direction shown by the arrow, and the seam part 2 is welded continuously by the body 5' of a fixed arc torch for TIG welding. A collet 7' is previded in a collet body 8 provided with a gas passaged inside of the body 5', and a W group electrode 4 is provided in the collet with its tip projected from a nozzle 6. An electrode pushing rod 22 is brought into contact with the rear end of the electrode 4 and the rear end is fitted to an electrode thrusting tool 23 screwed to inside of torch cap 14 provided at rear end. When welding, the distance G between the seam part 2 and the tip of the nozzle 6 is kept constant by screwing in the thrusting tool 23 according to consumption of the electrode 4, and at the same time, the distance g between the seam part 2 and electrode 4 is also nearly constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms a relatively thin metal tape into a circular shape and welds its seam under certain conditions without stopping the production line.

The purpose is to provide a welding method for the seam part of all sheathed pipes that does not cause quality variations even during long periods of time, such as m to i o, o o o m. The purpose of this invention is to provide an arc torch for

In recent years, as the development of optical fibers has progressed, their use has become more widespread.For example, when they are used in combination as communication information lines in overhead ground lines, they are attracting attention because they can be used without being subjected to electromagnetic induction.

In such cases, for example, it is manufactured by forming an aluminum tape onto a circular tube, inserting a filament such as an optical fiber or an electric wire therein, and then T-welding the seam part. As the tube becomes longer, the problem arises as to whether or not to stop the production line due to wear of the tungsten-based electrode such as tungsten or tungsten alloy of the arc torch. Since the actual production line involves feeding welded metal tubes into a multi-stage diameter reduction device, reducing the diameter, and performing a pinhole test to create a finished product, production may be stopped temporarily while the production line is in operation. This raises the possibility that defective parts may occur in welded parts and other parts of metal pipes that are to be manufactured under certain conditions.

Furthermore, if metal tape can be formed into a circular tube shape and the seams can be continuously welded, its application as a protective tube for optical submarine cables is even more promising, but the length is long. However, the conventional technology has many drawbacks.

As a result of various studies to solve the above-mentioned difficulties, the present invention maintains a constant distance G between the seam of a metal tube and the nozzle tip of an arc torch for TIG welding, and By keeping the distance g to the electrode constant, it is possible to manufacture metal welded tubes under certain conditions without stopping the production line at all.As a result, we are able to manufacture metal tubes that are not only efficient but also of excellent quality. Successful.

Furthermore, as a means for implementing this method, we provide an improved arc torch for T-work G welding that satisfies the above conditions.

Next, the present invention will be explained with reference to the drawings. , Fig. 1 is a cross-sectional view showing a metal tube containing a wire body such as an optical fiber cable, and the wire is inserted with a margin into the metal tube 3 which is formed by rolling a metal tape into a circular tube shape. A shaped body 1 is built in, and 2 indicates a seam portion.

By the way, Fig. 2 shows the case where the seam part of such a metal tube is welded using a conventional Tl() welding arc torch, where 1 is a filament such as an optical fiber cable, and 2 is a seam part of a metal tape. , 3 are metal tubes. The T-G welding machine has an electrode 4 made of tungsten or tungsten alloy,
Inert gas such as argon or helium is used as the encapsulating gas for the welding part.

And the main body 5 of such an arc torch for T-work G welding.
is fixed, and the seam portion 2 is continuously welded by moving the metal tube 3 in the direction of the arrow.

In addition, 6 in the figure is a collet I that supports the welding electrode with a nozzle.
The torch body 11 is screwed onto the nozzle 6 by a jacket 12 and an adapter 13, and the rear end portion A torch cap 14 is screwed onto the torch cap 14, and a gas supply port 1 is provided on a part of the side surface of the torch cap 14.
5, a cooling water supply port 16, and a drain port 17, and has a sealed structure with a rubber gasket 18 and an O-ring rubber 19. Further, 20 is an insulating sleeve.

The torch main body 5 is supported and fixed by a torch fixing part 21, and although not shown, this torch fixing part 21 is provided with a mechanism capable of moving in horizontal and vertical directions.

Tungsten-based electrodes such as tungsten or tungsten alloys used in TIG welding arc torches with this structure are known to have little wear during welding, but in reality they wear out little by little, so for example In the case of the protective sheathing for ordinary electric wire cables, the length is at most 1,500 m, so 500 V
When performing 1L welding, the electrode consumption is 1 to 2 WI, so
In order to keep the distance g between the seam portion 2 of the metal tube and the electrode 4 constant, it was adjusted by moving the torch body 5 downward. However, this movement of the torch body 5 is caused by the nozzle 6
The distance between the tip of the metal tube 3 and the seam 2 of the metal tube 3 changes, which causes the flow of inert gas in the encapsulated part 10 to fluctuate, resulting in a drawback that stable and good weldability cannot be obtained. .

In particular, the length of the optical fiber protection tube in the optical fiber composite overhead ground wire is 5,000 m to 10. OG OrILVc also extends, and the electrode wear is too large to weld the entire length, so it cannot be adjusted just by moving the torch body downwards, so the power source is turned to Qff each time to adjust the protruding length of the tip of the electrode itself. Since adjustment is necessary, there are major problems such as the occurrence of welding defects and a decrease in production efficiency. Moreover, in the production of protective tubes for optical submarine cables, it is predicted that the unit length will become even longer, so it is essential to solve this problem.

There is a method that detects the traveling speed of the metal pipe to be welded at the welding part and feeds back this information to control the welding current, but controlling the welding current alone does not provide perfect weldability. Protection tubes for optical fiber cables are required to have high airtightness.

The present invention provides a method for solving the above-mentioned difficulties and a welding torch for implementing the method.

That is, when manufacturing a long metal tube by forming the metal tape of the present invention into a tube shape and continuously welding the seam portion thereof, the distance G between the seam portion and the tip of the nozzle of the arc torch for TIG welding is determined. The seam part of a long metal pipe is welded by moving the tip of the electrode toward the seam part as the electrode wears out so as to keep the distance g between the seam part and the electrode constant. This is a book about a continuous welding method, a method in which a suppressor is provided behind the electrode to achieve this, and an arc torch.

That is, this will be explained with reference to FIG. 3. FIG. 3 is a longitudinal cross-sectional view of the main part of the present invention, and the same parts as in FIG. 2 are indicated by the same reference numerals.

A collet 7' is provided inside a collet body 8 in which a gas passage 9 is formed in the inner cavity, and a tungsten-based electrode 4 such as tungsten or tungsten alloy is provided in the inner cavity so that its tip protrudes from the nozzle 6. It is. Then, the electrode push rod 22 is brought into contact with the rear end 4-1 of the electrode 4, and the rear end of this electrode push rod 22 is inserted into the inner cavity of the torch cap 14' provided at the rear end of the torch body 5'. It has a structure in which it is fitted into an electrode pusher 23 that is screwed into this inner cavity.

The electrode push rod 22. Both the torch cap 14' and the electrode pusher 23 are made of an insulating material such as ebonite, Bakelite, or hard nylon.

Note that 24 is a silicone rubber gasket that seals the electrode 4 from the outside air. The rest of the structure is the same as that described in FIG. 2, so the explanation will be omitted.

When welding a long metal tube 3, the arc torch for T-work G welding according to the present invention screws in the electrode pusher 22 according to the wear of the electrode 4, and presses the electrode 4 into the metal tube to be welded. By pushing down toward the seam, the distance g between the seam of the metal tube to be welded and the tip of the electrode 4 becomes g+
What was separated by α is now yg again.

In this case, there is no need for the torch body 5' to move up and down at all, and the distance G between the contact end of the nozzle 6 and the seam of the metal tube to be welded is always kept constant, and the inert gas envelope 10 during welding is kept constant. The molten metal bath is completely protected from the atmosphere without any fluctuations in the flow at the molten metal, so that extremely good weldability can be achieved.

As described above, the present invention manufactures a long metal tube by welding the seam part of a metal tape, while keeping the relationship (distance G) between the T welding torch body and the seam part constant. Once every several hundred meters, the distance g between the seam and the electrode end that has increased as the electrode wears out is corrected and returned to the original size g, during which time the metal tape is formed,
The diameter reduction of the welded metal tube is carried out smoothly, and the metal tube as a product is also manufactured under constant conditions, so it has excellent airtightness.
The welding torch according to the present invention can easily produce long metal tubes of 0.00 ML or more, and although the welding torch according to the present invention has a structure that is not much different from conventional products, it has a mechanism that can easily push down the electrode. It is easy to operate and greatly contributes to the realization of the above method.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a formed metal tube containing a filament to be welded according to the present invention, and Fig. 2 shows a seam of the formed metal tube shown in Fig. 1 being welded using a conventional T welding arc torch. FIG. 3 is a partial longitudinal cross-sectional view showing a welding state in which the seam of the formed metal tube shown in FIG. 1 is welded by the method of the present invention and the TIG welding arc torch of the present invention. FIG. 1: Striatum 2: Seam portion 3: Metal tube 4: Electrode, 5
．． 5':)-Chi body 6: Nozzle 7.7': Collet 8: Collet body 9: Gas passage 10: Gas envelope part 14, 14': )-Chi gap 21: Fixing part 22: Electrode push rod 23: Electrode pusher representative Patent attorney Mamoru Takeuchi (11) Figure 2

Claims (2)

[Claims] (1) When manufacturing a long metal tube by forming a metal tape into a circular tube shape and continuously welding the seam portion, the seam portion m and the tip of the nozzle of the TI () welding arc torch Welding is carried out while keeping the distance #G constant and moving the electrode toward the seam portion at the tip as the electrode wears out so that the distance g between the seam portion and the electrode is also kept constant. Continuous welding method for long metal pipe seams (2) A continuous welding method for a seam portion of a long metal pipe according to claim 1, characterized in that the electrode is moved by a suppressing means behind the electrode (5) In an arc torch for TTG welding , at the rear end of the tungsten electrode inserted into the collet. An electrode push rod is brought into contact within the lumen of the collet. Furthermore, the rear end of this electrode push rod is fitted into an electrode pusher that is screwed into the inner cavity of a torch cap provided at the rear end of the torch body, and welding is performed by screwing this electrode pusher. An arc torch for T-work G welding of a long metal pipe sill entry part, characterized in that the distance g between the metal pipe seam and the electrode can be kept constant.