JPS6016307B2 - Method and device for internal welding of pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method and apparatus for welding the inner surface of a pipe in the dish pipe manufacturing method, and the purpose thereof is to perform continuous welding instead of intermittent inner welding for each pipe. There is a particular thing.

In the uo surface pipe method, generally when welding a steel pipe that has been formed and tacked together from the inside and outside, it is necessary to attach tube plates to both ends of the steel pipe in advance in order to feed the stock pipe one by one to the welding machine. Not only does this work require a considerable amount of time and effort, but it also involves idle time for loading and unloading steel pipes before and after welding, which is an obstacle to improving production efficiency. There were problems such as the tendency for welding defects to occur on the rear wheels due to magnetic blowing, etc. The present invention solves the problems of internal welding in the side pipe manufacturing method all at once, by sequentially butting the ends of the pipes to be welded together and welding continuously without using a tab plate. In addition, the power supply system was replaced during the welding process, and pipes to be welded were brought in and pipes to be welded were taken out during the welding process.

Hereinafter, the present invention will be explained using specific examples shown in the drawings.
FIG. 1 is a plan view of the equipment showing the welding process over time, and the welding machine and power supply boom are shown as a front view for ease of explanation. Reference numerals 1 and 2 are power supply booms arranged on the left and right at a predetermined interval, and their legs la and 2a are
It is said that it can freely move forward and backward towards the central part via.

3 is a welding machine truck on which a welding machine 4 is mounted, and electricity or shielding gas is supplied to the welding machine 4 through a power supply boom 1 or 2.

A turning roller 5 and a cage roll 6 are arranged between the power supply booms 1 and 2. Further, on the turning roller 5, the cage roll 6, and the exit side of the cage roll 6 (on the power supply boom 2 side), a transport table is configured by a group of transport rollers 7. A carry-in table 8 is provided on the side of the turning roller 5, and a carry-out table 9 is provided on the side of the conveyance table on the exit side of the cage roll 6.
Furthermore, a butt cutting saw 10 is provided on the exit side of the cage roll 6.
is installed. In this way, if there is a discrepancy in the ends of the pipes brought in prior to internal welding, both ends of the pipes are roughly chamfered by cutting before the pipes are brought in, so that the ends of the pipes are flush.

Now, the steel pipe 11 is carried onto the turning roller 5 via the carrying table 8. At this stage, with the side ends of the steel pipes 12 abutted against each other from the outside by the cage roll 6 as shown in figure a, the power supply boom 2 is placed against the end of the pipe 12.
Welding is performed by the welding machine 4 supplied with power from the welding machine 4. In this case, the welding machine truck 3 itself does not move, but the welding machine truck 3 travels relative to the pipe 12 due to the movement of the pipe 12. On the other hand, the pipe 11 carried in is rotated in all directions around the circumference by the turning roller 5, and the beveled side end thereof is set downward. When this is finished, the tube 11 is moved to the cage roll 6 side by the conveyor rollers 7, 7, . It will be done. As shown in Figure b, in this butt state, the pipes 11 and 12 are integrally conveyed toward the stone side in the drawing by the conveyor rollers 7, 7, etc., while the inner surfaces are welded continuously by the welding machine 4. It is done. Of course, the feeding speed of the tubes 11 and 12 is controlled so as to match the welding speed, and so that the lines to be welded on the internal vertical joints of the tubes 11 and 12 are on the same straight line. And finally, tube 12
The welding part reaches the left end of the pipe 11, but continues to cross over to the joint of the pipe 11 and continues welding the inner surface in the same manner. Next, when the abutting part of the tubes 11 and 12 approaches the left end of the carry-out table 9, the feeding fin boom 2 is removed, and instead of it, the feeding boom 1 is moved forward to continuously feed electricity. At the same time, the butt portions integrated by welding are cut by the cutting saw 10, and the tubes 11 and 12 are separated. This state is shown in figure c. Next, the separated tube 12 is carried out on the transfer table 9. On the other hand, once the pipe 11 that is currently being welded has been welded to some extent, the power supply boom 1 is removed, and the power supply boom 2 is brought in again in its place and welding is performed via this. This state is shown in figure e, which is the same as figure a. In other words, the internal welding of the tubes is sequentially performed through the cycle described above. By adopting such a method and equipment, continuous internal welding can be performed without attaching a tab plate to the tube end unlike in the case of a secondary weld, and without any pauses.

Since the bag is carried in and transported during the welding operation, there is no idle time during the welding operation. Furthermore, since the power supply boom is retracted during loading and unloading, there is no problem with loading and unloading work. Here, as the welding method, for example, single electrode or multi-electrode TIG welding can be used, and the welding machine 4 is preferably one having a tip tracing mechanism.

Furthermore, when welding passes from tube 12 to tube 11, molten metal may leak at the butt portion if the squareness is not sufficient during the rough chamfering stage. Therefore, in such a case, it is preferable to apply flux buckling to the abutting portion from the outside. Furthermore, if the outer surface welding is also performed at the cage roll 6 position in the above example, the inner and outer surface welding can be performed continuously, improving the welding quality of the pipe end, performing tap plateless welding, It can be expected to improve welding processing efficiency, make the entire welding equipment more compact, and reduce the number of personnel. On the other hand, when replacing the power supply booms 1 and 2, as shown in FIG. If the plug 15 is iron-inserted into the plug receiver 14 during forward movement without requiring manual operation, the replacement work will be extremely smooth. Since the present invention has the above configuration, it has the following great practical effects. That is, unlike the conventional method, welding is not performed one by one, but the welding process is continuous, and processing efficiency is greatly improved. In addition, in the intermittent processing process of the secondary, for example, when welding a steel pipe with a thickness of 15 mm and a length of 12 mm using a 3-electrode submerged arc welding method,
Previously, about 0 minutes were required, and in addition about 3 minutes of idle time was required, but according to the present invention, this idle time can be reduced to zero, and productivity is extremely high. Not only that, but since no tab plate is required, the installation time and work are eliminated, which is also advantageous. In addition, since welding is performed on the pipe ends in the same manner as on other parts, there is no occurrence of defects at the welding start and end ends unlike in the case of secondary pipes, which is highly effective in terms of improving welding quality. On the other hand, according to the device of the present invention,
Carrying in the pipe, aligning the seam, butting the joints, and driving, cutting, and carrying out the pipe are continuous, and the internal welding work is also continuous by changing the power supply boom, so that the method of the present invention can be smoothly achieved.

[Brief explanation of the drawing]

1A to 1E are schematic plan views illustrating a specific example of the present invention over time, and FIG. 2 is a front view of a power supply hoop replacement device provided on a welding machine truck. 1, 2...Power supply boom, la, 2a...
・Legs, 3...Welding machine trolley, 4...Welding machine, 5...Evening roller, 6...
Cage roll, 7... Conveyance roller, 8...
...Carry-in table, 9...Carry-out table, 10
・・・・・・Abutment cut lock, 11, 12・・・・・・
Steel pipe, 13...Support, 14...Plug receiver, 15...Plug. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1 In the internal vertical joint welding method in the UO pipe manufacturing method, a pair of left and right power supply booms of a welding machine are disposed at a predetermined interval so as to be movable toward the center, and a plurality of sheaths are arranged between them. The pipes to be welded are brought in, the ends of the pipes to be welded are butted against each other so that the internal vertical joint lines to be welded are on the same line, and the above-mentioned While switching the power supply system from one power supply boom to the other, continuous internal welding is performed using a welding machine, and once the entire length of the pipe has been welded, the mutual butt part is separated from the other pipes. The characteristic internal welding method of the UO pipe manufacturing method. 2. An internal welding method in the UO pipe manufacturing method according to claim 1, wherein flux packing is provided from the outside at the abutting portions of the pipes to be welded. 3. Power supply booms arranged at a predetermined interval in pairs facing the center on the left and right so that they can move forward and backward;
A turning roller that rotates the pipe to be welded in the circumferential direction that is supplied between the power supply booms, a cage roll that stably adjusts the side end surface to be welded, and a turning roller that moves from the turning roller to the cage roll side and then to one power supply boom side. a means for moving the welded pipe, a means for carrying the pipe to be welded to the turning roller, a means for carrying out the pipe moved to the one power supply boom side, and a butt portion cutting means provided on the exit side of the cage roll. and a welding machine truck equipped with a welding machine that runs relative to the pipe to be welded within the pipe to be welded at the cage roll position, and the power supply boom can change its power supply system to the welding machine at an appropriate time. An internal welding device for the UO pipe manufacturing method, characterized by: