JP2000052035A - Pipe welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently weld two pipes without tacking pieces by positioning the two pipes held by a holding tool coaxially on a horizontal face while operating the first and second alignment devices, and by moving a welding groove of the pipe to a butt portion. SOLUTION: The first and second alignment devices are equipped with a polar robot 14 activated on the basis of the command from a control device 13. The polar robot 14 is moved horizontally (in an X direction) in a manner that both pipes 6 become coaxial at a horizontal position, and a holding tool 15 is shrunk vertically (in a Z direction) and positioned. Furthermore, a fine angle is adjusted by the swing (θ) and rotation (ϕ) actions of the holding tool 15. After checking whether both pipes 6 are coaxial, welding grooves of the facing pipes 6 approach each other (in a Y direction), and placed at the butt position. Thereby, during the process from positioning to welding via groove butting, the horizontal and vertical positions of the pipes 6 are kept stable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe welding method used for welding pipes without using a tacking piece.

[0002]

2. Description of the Related Art In conventional pipe welding, a chain block suspended from a beam is used to place two pipes to be welded at a predetermined welding position. While maintaining the position of both pipes with this chain block, face the welding groove,
Temporarily attach both pipes by welding using a piece for temporary attachment,
Further, a series of operations for performing the main welding after the final groove alignment are performed to complete the welding. The temporary attachment piece is removed from the pipe after the welding is completed to finish the surface, and all operations are completed.

More specifically, referring to the drawings, as shown in FIG. 4, a pipe 6 is firstly suspended by a chain block 5 suspended from a beam 4 using a wire 3 of a winch 2 extending from a column 1 to a column 1. Hang and support. Since the position of the pipe 6 is not determined in this state, one pipe 6 and the other pipe 6 are then placed at positions where the welding grooves face each other as shown in FIG. The two pipes are temporarily attached by welding using the temporary attachment piece 7 shown in FIG. Further, the welding groove is aligned so that both pipes 6 are concentric, and the welding groove is filled with welding metal 8 and welded while maintaining the position. After the welding is completed, the joining portion of the tacking piece 7 is cut off, the tacking piece 7 is removed from the pipe 6, and the surface is finished by slightly shaving the attachment trace to finish the work. In the figure, reference numeral 9 denotes a wire,
Used for hanging.

[0004]

In the above-described method for welding pipes, it is difficult to determine the position of the pipe 6 in the air, especially the horizontal position. That is, the chain block 5 supporting the pipe 6 has no special means for fixing its own position, and a slight movement of the chain block 5 directly displaces the pipe 6 so that the horizontal position is greatly disturbed.
Even if the chain block 5 can be fixed, it is the wire 9 that directly hangs the pipe 6, and the horizontal position is increasingly disturbed by the swinging movement of the wire 9.

The only thing used to eliminate extreme horizontal misalignment and at the same time eliminate vertical misalignment is a temporary attachment piece 7 which is attached to both pipes 6.
It is. However, it is not preferable to temporarily attach the temporary attachment piece 7 by welding, since the removal is unavoidably performed in a later operation.

If the deviation of the horizontal and vertical positions can be reduced without using means such as the tacking piece 7, all operations such as manufacturing, mounting and removing the tacking piece 7 are omitted. By eliminating waste, efficiency in this type of work can be dramatically improved.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for welding pipes which can be welded without using pieces for tacking while holding both pipes to be joined at desired positions. .

[0008]

To achieve the above object, there is provided a welding method comprising the following steps. First, the first alignment device and the second alignment device are fixed at a distance on one straight line of the fixed member. Next, among the pipes to be welded, one pipe is gripped by the gripping tool of the first alignment device, and the other pipe is gripped by the gripping tool of the second alignment device. Next, the pipe held by the gripper is positioned so as to be concentric in the horizontal plane by operating the first and second alignment devices, and the welding groove of the pipe is moved to the mating position. Next, the welding groove of both butted pipes is welded.

In such a welding method, positioning,
Through the beveling and welding, the horizontal and vertical positions of the pipe can be kept stable by the first and second alignment devices. Thereby, the horizontal and vertical positions of the pipe at the time of welding can be kept at the exact positions obtained by positioning and groove alignment without using means such as a tacking piece.

In order to realize this welding method, it is desirable that the grippers of the first and second alignment devices are movable in two directions perpendicular to each other in a horizontal plane and in one direction in a vertical plane. You. Further, the gripper is configured to rotate in a horizontal plane and to be pivotable in a vertical plane.

[0011] At the time of positioning and groove alignment of the pipe using the gripping tools of the first and second alignment devices, the pipe is moved to a desired position while being moved, rotated and turned.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As a desirable means for realizing the method of the present invention, a first alignment device 11a and a second alignment device 11 that hang from two points on a straight line of the beam 4 as shown in FIG. 2 are used. Both the first and second alignment devices 11a and 11b
The first attached to two points on the straight line above
And the second holders 12a and 12b.

The first alignment device 11a is provided with a polar coordinate robot 14 that operates based on a command from the control device 13. Also, the second alignment device 11
The same polar coordinate robot 14 is provided in b. The polar robot 14 has a gripping tool 15, and two pipes 6 to be butt-welded are gripped by the tip of the gripping tool 15.

Further, the first and second alignment devices 11a each have a moving mechanism (not shown) for moving the polar robot 14 in two directions (indicated by X and Y in the figure) on a horizontal plane by a step motor. ing. The above-described polar coordinate robot 14 can be extended and contracted (indicated by Z in the drawing), turned (θ) and rotated (φ) by a step motor, and cooperates with the moving mechanism to hold the gripper 1.
The position of the pipe 6 at the tip 5 can be freely changed according to a command.

An auxiliary suspending member 16 is provided on the side of the pipe 6 opposite to the side to be gripped by the gripping member 15. The auxiliary suspending device 16 is used to prevent the long pipe 6 from being lowered by its own weight, and does not restrict the movement of the pipe 6 at the time of positioning, or tighten the clamp after the positioning to move the pipe 6. Can be restrained. Although only one auxiliary hanging device 16 is shown in the figure, a plurality of auxiliary hanging devices may be used according to the length of the pipe 6.

The welding method according to the present invention will be described with reference to FIG. First, the first and second alignment devices 11a and 11b are attached to the beam 4 on a straight line at a distance from each other and fixed so as not to move (first step). Next, one of the pipes 6 to be butt-welded is connected to the first pipe.
Of the polar coordinate robot 14 of the alignment apparatus 11a. Further, the other pipe 6 to be welded is gripped by the gripper 15 of the polar coordinate robot 14 of the second alignment device 11b (second step).

At this time, the welding groove of the pipe 6 is opposed to the other welding groove. In particular, the piping 6
When the joint is not yet joined on the side opposite to the side where is gripped, as shown in FIG. 2, an auxiliary hanging member 16 is attached to the opposite side to support the pipe 6. In this case, the auxiliary hanging member 16 does not firmly fix the pipe 6 by a clamp before performing positioning and groove alignment, but supports the pipe 6 loosely.

Next, the polar coordinate robot 14 is moved horizontally (X direction) so that both pipes 6 are concentric at the horizontal position, and the gripping tool 15 is extended and contracted vertically (Z direction) for positioning. Further, the minute angle is adjusted by turning (θ) and rotating (φ) the gripping tool 15 of the polar coordinate robot 14. After confirming the concentricity of both pipes 6, the welding groove of both facing pipes 6 is moved closer (Y direction), and FIG.
As shown in (3).

Next, at this abutting position, the welding groove of both pipes 6 is filled with welding metal 8 and welded (fourth).
Process). The pipe 6 is integrally joined by this welding. The horizontal and vertical positions of the pipe 6 are stably maintained by the first and second alignment devices 11a and 11b while the welding proceeds from the positioning of the pipe 6 to the welding through the groove alignment.
That is, after the positions of both pipes 6 are determined by the open loop control, the first and second alignment devices 1
No input is given to 1a, 11b, and the horizontal and vertical positions of the pipe 6 at the time of welding are determined without using a means such as a tacking piece, and the accurate position obtained by the groove alignment is maintained. be able to.

Therefore, it is possible to omit all operations such as production, attachment, and removal of the piece for temporary attachment, and it is possible to eliminate waste, thereby greatly improving the efficiency in welding the pipe 6. .

Further, the positioning and groove alignment of the pipe 6 can be performed semi-automatically, and the efficiency in the preparation stage for welding can be greatly improved.

Further, since the positioning accuracy of the welding groove is improved, the work can be more efficiently performed in welding.

Thereafter, the first alignment device 11a and the second alignment device 11b
Is removed (fifth step). When the opposite side of the pipe 6 is fixed by the auxiliary hanging member 16, the auxiliary hanging member 16 is removed from the pipe 6.

As described above, according to the present embodiment, the piping 6
Can be stably maintained by the first and second alignment devices 11a and 11b,
By not using a means such as a temporary attachment piece, all operations such as production, attachment and detachment can be omitted, and the efficiency in welding can be greatly improved.

[0025]

As described above, in the present invention,
The horizontal and vertical positions of the pipe can be stably maintained by the first and second alignment devices, and the horizontal and vertical positions of the pipe during welding can be positioned and grooved without using means such as temporary attachment pieces. It is possible to continue to hold the accurate position obtained in the above.

Therefore, according to the present invention, it is possible to omit operations such as production, attachment, and removal of a piece for temporary attachment, and it is possible to dramatically improve the efficiency in welding pipes.

[Brief description of the drawings]

FIG. 1 is a process chart showing a pipe welding method according to the present invention.

FIG. 2 is a view showing a welding process using the alignment device according to the present invention.

FIG. 3 is a view showing a state of bevel alignment according to the present invention.

FIG. 4 is a view showing a conventional pipe welding process.

FIG. 5 is a view showing a state of groove fitting of a conventional pipe.

FIG. 6 is a cross-sectional view illustrating an example of a temporary attachment piece that connects pipes.

[Explanation of symbols]

 Reference Signs List 4 beam 6 piping 11a first alignment device 11b second alignment device 14 polar coordinate robot 15 gripper 16 auxiliary suspension

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akira Yokota 3-7-1, Nishishinbashi, Minato-ku, Tokyo Toshiba Plant Construction Co., Ltd. F-term (reference) 4E081 AA12 AA14 BA27 DA05 DA11 DA32 EA43 EA47

Claims (2)

[Claims] 1. A step of fixing a first alignment device and a second alignment device at a distance on a straight line of a fixed member, and gripping one pipe to be welded by a gripper of the first alignment device. Causing the other alignment pipe to be gripped by the gripping tool of the second alignment device, and concentrically holding the pipe held by the gripping tool in a horizontal plane by operating the first and second alignment devices, respectively. And a step of moving the welding groove of the pipe to a butt position, and welding the welding groove of both the butt pipes. 2. The gripper of the first and second alignment devices is movable in two directions orthogonal to each other in a horizontal plane and one direction in a vertical plane, and rotates in a horizontal plane;
Furthermore, it is configured to be pivotable in a vertical plane, and at the time of positioning and groove alignment of the pipe, the pipe held by the gripper is moved to a desired position while being rotated, rotated and turned. The method for welding pipes according to claim 1, wherein: