JPH0456719B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a water flow welding device for abutting pipes together, passing water inside the pipes, and welding the abutted portions from the outside while rotating around an axis. .

[Technical background of the invention]

When butt welding pipes together, stress corrosion cracking (SCC) due to heating of the welded area may occur.
There is a concern that cracks may occur. Therefore, water flow welding is widely practiced in which the abutting portions of both base materials are welded from the outside while cooling water is passed through the base metals to prevent the base metals from being heated from the inside.

FIG. 2 shows a water flow welding apparatus, and in the figure, reference numerals 1 and 2 are base metal tubes, and these base metal tubes 1 and 2 are arranged substantially horizontally, with one end abutted against each other. The open end of one of the base material tubes 1 is closed with a closing plate 4 of the water flow welding device 3, and the open end of the other base material tube 2 is closed with a cover plate 5. The water flow welding device 3 has a structure in which a cooling water inlet nozzle 6 is provided through an eccentric portion of the closing plate 4, and a cooling water outlet nozzle 7 is rotatably provided through the central position of the closing plate 4. It is something. In the figure, 8 is a bolt for attaching the closing plate 4 to the flange of the base pipe 1, 9 is a sealing O-ring inserted between the closing plate 4 and the cooling water outlet nozzle 7, and 10 is a cooling bolt. This is a bearing that rotatably supports the water outlet nozzle 7. In the figure, 11 is a sealing O-ring inserted between the flange of one base material pipe 1 and the closing plate 4, and 12 is the other base material pipe. This is a sealing O-ring inserted between the end surface of the material tube 2 and the cover plate 5.

The closing plate 4 of the water flow welding device 3 is held by a rotating chuck of a rotating device (not shown), and the center of the cover plate 5 is pressed in the axial direction from the outside by the center of a tailstock (not shown). .

In this state, while rotating the rotary chuck, the bottom of the groove at the abutting portion of both base material tubes 1 and 2 is welded at the initial layer as shown by 13 in the figure. After water leakage from the abutting portion is prevented in this way, the cooling water 14 is filled from the cooling water inlet nozzle 6 into the insides of both base material tubes 1 and 2, and the cooling water 14 is filled from the cooling water outlet nozzle 7. The cooling water 14 is allowed to flow out, and the welding of the abutting portions is continued while the base material tubes 1 and 2 are again rotated by the rotating device. Note that, from the viewpoint of workability, this welding is performed with the welding torch facing downward at the upper part of the base material tube.

[Problems with background technology]

When water welding is carried out as described above, the insides of both base metal tubes 1 and 2 are sealed spaces, so if air bubbles 15 exist inside, the air bubbles 15 will be transferred to the base metal tubes as shown in FIG. , 2 stays in the uppermost part inside. For this reason, the cooling water 14 cannot come into contact with the inner peripheral surfaces of the base metal tubes 1 and 2 at the uppermost portion where the air bubbles 15 exist, and the cooling effect on the base metal tubes 1 and 2 is impaired, resulting in a welded portion and its vicinity. There is a risk that the soundness of the system may be damaged. In particular, as shown in Figures 2 and 3, when the inner diameter of the base material tubes 1 and 2 near the abutting parts is larger than other parts, the large diameter parts 1a and 2a The air bubbles 15 remain and the cooling effect of the welded part that should be cooled the most is impaired, leading to the risk of SCC occurring.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to abut the base material tubes disposed almost horizontally to allow water to flow inside, and to rotate the base material tubes about their axes while rotating the abutted portions. A water welding device that welds pipes from the outside prevents air bubbles from accumulating inside the base material pipe, and can perform welding without damaging the integrity of the welded part and its surrounding areas. It is about providing.

[Summary of the invention]

In order to achieve the above object, the present invention provides water flow welding in which base metal tubes arranged substantially horizontally are butted against each other, water is passed inside, and the abutted portions are welded from the outside while rotating around an axis. The apparatus includes a closing plate that closes an end of at least one of the base material pipes, a cooling water inlet nozzle that passes through the closing plate and allows cooling water to flow into the base material pipe, and a center of the closing plate. A cooling water outlet nozzle is provided so as to be rotatable relative to the blockage plate through the blockage plate, and its tip opening is located at the top near the abutting portion of both base material tubes.

With this configuration, the tip opening of the cooling water outlet nozzle is always located at the top, so even if air bubbles occur at the uppermost position inside the base material tube, they are quickly discharged through the cooling water outlet nozzle. It is possible to reliably prevent air bubbles from accumulating inside the material pipe, and the cooling effect of the welded part and its vicinity is enhanced.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIGS. 2 and 3 are given the same reference numerals.

That is, in the figure, reference numerals 1 and 2 are base material tubes, and these base material tubes 1 and 2 are arranged substantially horizontally, with one ends abutting each other. The open end of one base material pipe 1 is closed with a closing plate 4 of the water flow welding device 3, and the open end of the other base material pipe 2 is closed with a cover plate 5. The water flow welding device 3 has a configuration in which a cooling water inlet nozzle 6 is provided through an eccentric portion of the closing plate 4, and a cooling water outlet nozzle 17 is rotatably provided through the central position of the closing plate 4. It is something.
In the figure, 8 is a bolt for attaching the closing plate 4 to the flange of the base pipe 1, 9 is a sealing O-ring inserted between the closing plate 4 and the cooling water outlet nozzle 17, and 10 is a cooling bolt. This is a bearing that rotatably supports the water outlet nozzle 17. In the figure, 11 is a sealing O-ring inserted between the flange of one base material pipe 1 and the closing plate 4, and 12 is the other one. This is a sealing O-ring inserted between the end surface of the base material tube 2 and the cover plate 5. Further, the inner diameter of the base material tubes 1 and 2 near the abutting portions is larger than other portions (large diameter portions 1a and 2a).

The cooling water outlet nozzle 17 has a ring-shaped portion introduced into the inside of the base material pipe 1, and the large diameter portion 1
The tip 18a of the annular portion 18 is positioned along the inner circumferential surface of the tube a, with the tip 18a of the annular portion 18 facing the abutting portion of both the base material tubes 1 and 2.

The closing plate 4 of the water flow welding device 3 is held by a rotating chuck of a rotating device (not shown), and the center of the cover plate 5 is pressed axially from the outside by the center of a tailstock (not shown). . Also, the cooling water outlet nozzle 17
is fixed such that the tip 18a of the annular portion 18 is always at the uppermost position.

In this state, while rotating the rotary chuck, the bottom of the groove at the abutting portion of both base material tubes 1 and 2 is welded at the initial layer as shown by 13 in the figure. After water leakage from the abutting portion has been prevented in this way, the cooling water 14 is caused to flow into the base material tubes 1 and 2 from the cooling water inlet nozzle 6, and the cooling water 14 flows inside both the base material tubes 1 and 2. The cooling water 14 is flowed out from the cooling water outlet nozzle 7, and the welding of the abutting portion is continued while the base material tubes 1 and 2 are rotated again by the rotating device.

In the above configuration, even if air bubbles are generated inside the base material pipes 1 and 2, the air bubbles are always present at the uppermost position of the internal space and are sucked into the cooling water outlet nozzle 17, and are passed through the cooling water outlet nozzle 17 to the outside. Since the air bubbles are discharged to the base material tubes 1 and 2, no air bubbles remain inside the base material tubes 1 and 2. Therefore, the inner circumferential surfaces of the base material tubes 1 and 2 are always in contact with the cooling water 14, and the welded portion and its surrounding area are efficiently cooled.

[Effects of the Invention] As explained above, according to the water flow welding device of the present invention, by locating the tip of the cooling water outlet nozzle near the abutting portion of both base metal tubes, air bubbles are prevented inside the base metal tube. It is possible to prevent water from accumulating, and to improve the contact state between the inner circumferential surface of the base material pipe and the cooling water, so that welding can be performed without impairing the integrity of the welded part and its vicinity.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view showing a conventional example, and FIG. 3 is a sectional view showing a part of FIG. 2. 1, 2...Base metal pipe, 3...Water welding device, 4...
...Closure plate, 6...Cooling water inlet nozzle, 17...Cooling water outlet nozzle.

Claims (1)

[Scope of Claims] 1. A water flow welding device for abutting base metal tubes disposed substantially horizontally, passing water inside the tubes, and welding the abutted portions from the outside while rotating the tubes about an axis, comprising at least a closing plate that closes an end of one base material pipe; a cooling water inlet nozzle that passes through the closing plate and allows cooling water to flow into the base material pipe;
A cooling water outlet nozzle is provided which penetrates the center of the blocking plate and is rotatably provided with respect to the blocking plate, with its tip opening positioned at the top near the abutting portion of both base material tubes. water welding equipment. 2. The water flow welding according to claim 1, wherein the cooling water outlet nozzle has a portion introduced into the base material pipe having an annular shape and extending along the inner circumferential surface of the base material pipe. Device.