JPH0350640B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to water supply piping, piping for various plants,
Steel pipes are often used for heating and cooling piping in buildings.
The present invention relates to a pipe butt welding jig used for circumferentially welding metal pipes such as stainless steel pipes and iron pipes in a butt state mainly on-site.

[Conventional technology]

Conventionally, as this type of jig for butt welding of tube ends, the ones described below have been known.

Both pipes were fixed by tightly fitting a ring-shaped jig onto the inner surface of the pipe to be welded, with the pipe ends facing each other, so that the abutting surfaces spanned both sides in the pipe axis direction (for example, (Japanese Unexamined Patent Publication No. 11792/1983).

A half-cylindrical jig with flanges is visually displayed on the outer surface of the pipe to be welded with the pipe ends facing each other, with the abutting surfaces spanning both sides in the pipe axis direction, and the jig's cylinder A welding window is formed in the peripheral wall to fix both tubes together when the flange portions of the half-cylindrical bodies are connected (for example, Japanese Utility Model Publication No. 8097/1983).

[Problem to be solved by the invention]

In the prior art described above, processing precision of the ring-shaped jig is required, and there is a problem in that it is difficult to remove the ring-shaped jig after welding.

In addition, although the conventional method described above is useful in that it can solve the above problems, it does not have a structure in which the cylindrical body is divided in half and the flange portions are connected by bolts. Since the cylindrical body portion is provided relatively long on both sides of the abutting surface of the pipe to be welded, the flange in the circumferential direction of the pipe and the bent portion of the elbow pipe are provided very close to the abutting surface. In addition to the problem that it is difficult to use such pipes when the After partially welding a part, when moving to the next welding position, it is necessary to move the torch greatly in the radial direction to bypass the flange part, and in order to increase the clamping force, the torch must be moved radially The more they were used, the more time was likely to be lost.

The purpose of the present invention is to provide a device that can be easily attached to and detached from a pipe to be welded, has few restrictions on the applicable locations, has excellent versatility, and is capable of moving a welding torch from one welding window to the next welding window. Another object of the present invention is to provide a jig for butt welding pipes, which can be performed quickly and with less unnecessary movement.

[Means to solve the problem]

The technical means of the present invention for achieving the above object is to closely contact the outer circumferential surface of the welded tube on both sides of the abutting surface in the tube axis direction of the welded tube whose end surfaces are brought into butt contact with each other. In a jig for butt welding a pipe, the jig includes a cylindrical body having a series of inner circumferential surfaces that can be used, and a fixing fitting for fixing the cylindrical body in position relative to the pipe to be welded, as described in [A] below. It is equipped with the configuration described in ~[B].

[A] The cylindrical body is composed of a divided circular arc member divided into a plurality of parts in the circumferential direction, and has a welding window formed in its peripheral wall.

[B] The fixing fitting includes a split annular clamp body configured to be able to be fitted onto and released from the side of the cylindrical body that is fitted onto the pipe to be welded, and the clamp body. The cylindrical body is made up of a tightening tool that draws the cylindrical body toward each other and tightens the cylindrical body in the direction of diameter reduction.

[C] The cylindrical body and the fixing metal fitting are arranged so that the portion of the circumferential wall of the split arc member having the welding window protrudes to one side in the axial direction of the clamp body. The mounting position and dimensions in the tube axis direction are set.

[Effect]

The effects of taking the above technical measures are as follows.

a) Since the cylindrical body and the fixture are divided into a plurality of parts and fitted from the outside of the pipe to be welded, it is easy to attach and remove the jig to the pipe to be welded.

b Since the cylindrical body is fixed to the tube to be welded by tightening the clamp body that fits onto the cylindrical body in the diametrical direction, the flange portion is provided on the cylindrical body itself, and the flange portion is tightened. Compared to the case of tightening by pulling, the entire clamp body can be tightened more strongly.

c The cylindrical body is such that the peripheral wall of the part that does not form the welding window is strongly held by the clamp body of the fixing fitting, and the peripheral wall of the part that forms the welding window is aligned in the axial direction of the clamp body. Since the welding window is positioned so as to protrude in the direction, the welding window can be mounted on the periphery of the abutting surface without the cylindrical body protruding significantly on the other side of the abutting surface, and There is also no member such as a flange portion for tightening the cylindrical body around the abutting surface that protrudes largely in the radial direction.

〔Effect of the invention〕

Due to the above action, the jig can be easily attached to and removed from the pipe to be welded, and it can also be used for pipes to be welded where the flange in the pipe circumferential direction or the curved part of the elbow pipe is located very close to the butt surface. A jig with excellent versatility that can be used as an effective jig and has few restrictions on the locations to which it can be applied has been obtained.

In addition, the welding torch can be moved from one welding window to the next welding window quickly with less unnecessary movement, making it easier to perform efficient welding work. It is.

〔Example〕

Embodiments of the present invention will be described below in detail based on the drawings. In FIGS. 1 and 2, 1 is a cast iron cylindrical body, which is a welded pipe P ₁ whose end faces are butt-jointed, A series of inner circumferential surfaces _1A , 1A along the axial direction that can be brought into close contact with the outer circumferential surfaces of the pipes to be welded P ₁ , P ₂ across both sides of the butt surface A of P 2 in the axial direction. A plurality of sizes 1', 1'' which are composed of two circular arc members 1B, 1B divided into two halves in the circumferential direction, and whose inner peripheral surfaces 1A, 1A have different diameters. Two pipes are shown in the drawing, but three or more pipes are usually prepared depending on the pipe size.

Reference numeral 2 denotes a fixing fitting that fixes the position of the cylindrical body 1 relative to the welded pipes P1 and P2, and is a fixture that fixes the position of the cylindrical body 1 with respect to the welded pipes P1 and P2, and is attached from the side to the cylindrical body 1 that is fitted onto the welded pipes P1 and P2. Separate annular clamp bodies 2A, 2A configured to be able to be fixed and released from the outside
and a fastener 5 that draws the clamp bodies 2A, 2A toward each other and tightens them in the diameter reduction direction of the cylindrical body 1. The clamp body 2
A, 2A are pivotally connected to each end in the circumferential direction via a shaft 4 so as to be able to swing open and close, and are provided at the other end of the clamp body 2A in the circumferential direction. Gate type latch 7A, engagement bolt 7B,
By the fastener 5 consisting of the engaged recess 8 provided on the other end side in the circumferential direction of the other clamp body 2A,
It is configured to be freely switchable between a first state in which it is fixedly held in an annular position and a second state in which it is released from the fixation. In this way, by switching between the first state and the second state, the pipes P ₁ and P ₂ to be welded can be fitted and fixed from the side, released from the fixation, and pulled out to the side. There is.

The divided circular arc members 1B, 1B constituting the cylindrical body 1 are attached to the clamp bodies 2A, 2A, and the peripheral wall portions 1C, 1C corresponding to about half of the axial direction thereof are attached to the clamp bodies 2A, respectively. ,2A
The cylinder is fitted and fixed through bolts 9, 9 in such a manner that it protrudes from one side in the axial direction, and in a state in which the aforementioned plural sizes 1', 1'' can be replaced. A plurality of tack welding windows 3 (four are shown in the drawing, but two or more are sufficient) are provided in the circumferential direction on the protruding peripheral wall portions 1C, 1C of the shaped body 1, [1', 1'']. , 3 are formed.

The jig configured as described above is installed so that the window 3 is located along the abutting surface A of the pipes P ₁ and P ₂ to be welded, and one pipe P ₂ is fitted externally. Torch 10 in TIG welding equipment W
The tungsten electrode 11 is aligned with the abutting surface A, and in this state, the entire welding device W is rotated around the axis of the pipe P via a roller 13 pivotally supported on the device frame ₁₂ , and each window 3, By bringing the tungsten electrode 11 into contact with the outer periphery of the abutting surface A at point 3, the two pipes P ₁ and P ₂ are used for butt welding. During this tack welding, if the pipes to be welded P ₁ and P ₂ are vertical pipes in a vertical positional relationship as shown in FIG. End face 1
a and 1a are the frames 12 in the welding device W;
Since the welding device W comes into contact with the lower end surface of the tube to receive and support its weight, the position of the welding device W in the tube axis direction is stabilized, and the accuracy of the tack welding position is improved.

In addition, in connection with this, during circumferential main welding after the above-mentioned tack welding, the position of the jig is shifted downward and the direction of the welding device W is reversed, as shown in Fig. 4. By adopting a working configuration in which the weight is received and supported by a jig, it can also be effectively used as a jig for improving the accuracy of circumferential main welding.

The above-mentioned TIG welding device W was the one shown in Utility Application No. 114542/1987 filed earlier by the present applicant, but any other type of device that rotates around the pipe may be used. TIG welding equipment,
It may be a MIG welding device or the like.

Furthermore, among the cylindrical bodies, for the small diameter one 1', the inner circumferential surfaces 1A, 1A of the protruding circumferential wall parts 1C, 1C
Since the tubes to be welded P ₁ and P ₂ are to be tightened and fixed, the recess 1 is designed to reduce the weight as much as possible.
It is desirable to form D'.

FIG. 5 shows another embodiment, in which the welding window 3
To the extent that the required strength of the cylindrical body 1 can be ensured, there are two in the circumferential direction and as long as possible along the circumferential direction, thereby shortening the main welding length after the final welding. It is something.

[Brief explanation of drawings]

The drawings show an embodiment of the pipe butt welding jig according to the present invention, in which Fig. 1 is a perspective view, Fig. 2 is a longitudinal sectional front view, and Figs. 3 and 4 are partially cutaway views showing the state of use. The front view and FIG. 5 are longitudinal sectional side views of main parts showing another embodiment. P ₁ , P ₂ ... Pipe to be welded, A ... Butt surface, 1...
...Cylindrical body, 1A...Inner peripheral surface, 1B...Divided circular arc member, 2A...Clamp body, 1C...Protruding peripheral wall portion, 3...Welding window, 5...Fastening tool.

Claims (1)

[Claims] 1. A pipe to be welded P1 whose end faces are brought into butt contact with each other,
A cylindrical body 1 having a series of inner circumferential surfaces 1A, 1A that can be brought into close contact with the outer circumferential surfaces of the pipes to be welded P1, P2 on both sides of the butt surface A of P2 in the tube axis direction.
and a fixing fitting 2 for positionally fixing the cylindrical body 1 relative to the pipes to be welded P1 and P2, and for butt welding of pipes, which is provided with the configurations described in [A] to [B] below. jig. [A] The cylindrical body 1 is composed of divided circular arc members 1B, 1B divided into a plurality of parts in the circumferential direction, and a welding window 3 is formed in the peripheral wall part 1C. [B] The fixing fittings 2 are attached to the welded pipes P1, P.
The split annular clamp bodies 2A, 2A are configured to be able to be fitted onto and released from the side of the cylindrical body 1 which is fitted onto the cylindrical body 2, and the clamp bodies 2A, 2A are pulled together. A fastener 5 that tightens the cylindrical body 1 in the direction of diameter reduction.
It is composed of. [C] The cylindrical body 1 and the fixing fitting 2 are such that a portion of the circumferential wall of the divided circular arc members 1B, 1B, which has the welding window 3, protrudes to one side in the axial direction of the clamp bodies 2A, 2A. to be located in the state,
The mounting positions and dimensions in the tube axis direction are determined. 2 The cylindrical body 1 is connected to the clamp bodies 2A, 2
It can be attached to and detached from A, and its inner peripheral surface 1
The pipe butt welding jig according to claim 1, wherein the pipe butt welding jig is of a plurality of sizes with different diameters of A and 1A.