JPH0618707Y2 - Pipe welding shield device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a shield device suitable for arc welding of a peripheral joint of a long pipe of an active metal material such as Zr or Ti which is easily oxidized.

[Conventional technology]

When arc-welding an active metal material such as Zr or Ti, which is very easily oxidized, it is necessary to shield the surface of the weld bead with an inert shield gas until it cools.
Conventionally, in flat plate butt welding, an after shield box as shown in the perspective view of FIG. 5 has been put into practical use. That is, in the figure, the butt groove 2 of the flat plate 21
The shield box 24 connected to the rear side of the welding torch 23 facing the No. 2 is provided with a shield gas supply pipe 25 and a large number of gas lens holes 26 at its tip region.
The Ar gas 27 flows out from here, and the surface of the welding bead 28 at high temperature is shielded in an inert gas atmosphere to prevent its oxidation.

However, when welding butt peripheral joints of active metal material pipes, particularly when welding while rotating the welding torch along the peripheral joints of fixed long pipes, the shield box must be able to rotate according to the rotation of the welding torch. On the other hand, on the other hand, it is necessary to have a sufficiently sealed structure to prevent the entry of atmospheric air, and a device that can satisfy both of these conditions has not yet been developed. Therefore, in the current laboratory,
The means for welding by welding the entire pipe to be welded in a large inert gas atmosphere chamber is used, but this method has a limitation in the length of the pipe, and there is a problem that it cannot be applied to on-site welding.

[Problems to be solved by the device]

The present invention has been proposed in view of such circumstances,
It can be easily attached to long pipes, allows high-performance shielding while allowing the welding torch to swivel, and can be used for on-site welding. Furthermore, it is cheaper to manufacture than a large inert gas atmosphere chamber. Moreover, it is an object of the present invention to provide a pipe welding shield device that facilitates welding work.

[Means for Solving the Problems]

For this reason, the present invention has a structure in which a peripheral member of a fixed long pipe is sandwiched between the outer peripheral member and a peripheral member at a proper interval and a seal member is tightly fitted between them.
A pair of ring-shaped support frames having a two-divided structure and a vertically divided two-division structure shield tube having both ends rotatably engaged with and supported by the support frames and having holes for inserting a welding torch formed therein And an inert shield gas introduction port provided on the outer surface of the support frame and a large number of small-diameter blow-out holes bored in various directions in the shield cylinder on the inner surface of the frame. And

[Action]

In the device of the present invention, when welding is performed by rotating the welding torch around the peripheral joint of the pipe, the shield tube also rotates along with the movement of the welding torch and follows the movement of the welding torch without restraining it. The shield gas flows out in various directions inside the shield cylinder from the many shield gas blow-out holes on the inner surface, the cylinder is filled with the shield gas, and the surface of the welding bead of the peripheral joint is completely covered with the shield gas. Mixing and oxidation are properly prevented.

〔Example〕

An embodiment in which the shield device for pipe welding of the present invention is applied to the pipe all-orientation TIG welding will be described with reference to the drawings. FIG. 1 is a perspective view of the entire device, and FIG. (A) is a perspective view of a support frame, (B) is a perspective view of a shield cylinder, and (3) and (4) are a partially broken front view and a partially broken side view of FIG. 1, respectively.

In the above figure, a pair of ring-shaped metal support frames 3 of a two-part structure that can be half-opened on the circumference are externally fitted to the outer periphery of the fixed long pipe 1 with the peripheral joint 2 sandwiched therebetween and the patchon. The sponge packing 4 fixed by the lock 5 and attached to the inner peripheral surface of the support frame 3 is in close contact with the outer periphery of the pipe 1 to hold the seal. A small projecting edge 6 that is bent inward is provided on the peripheral edge of the support frame 3, and a plurality of rollers 7 are mounted on the circumference thereof by pins 7a. Between the pair of support frames 3, a transparent glass shield tube 8 having a vertically divided two-division structure is supported by interposing both ends of the shield tube 8 in rotatable contact with the rollers 7 of the support frame 3, Peripheral joint 2 of pipe 1
And its surroundings.

A torch hole 10 into which the welding torch 9 is inserted and a welding rod hole 12 into which the welding rod 11 is inserted are formed in the center of the shield cylinder 8. Further, a shield gas introduction port 13 for introducing an inert shield gas is provided on the outer side surface of the support frame 3, and the center direction, the peripheral direction, and the middle thereof in the shield cylinder 8 are provided over the entire circumference of the inner side surface of the frame 3. A large number of small-diameter shield gas blowing holes 14 oriented in various directions such as the direction are formed.

In such an apparatus, when welding is performed while the welding torch 9 is swung around the pipe 1 and the welding rod 11 is fed and melted to the peripheral joint 2, both ends of the shield tube 8 also move as the welding torch 9 moves. By freely rotating by the roller 7, the movement of the welding torch 9 is followed without being restricted.

Further, as shown in FIG. 3, the torch shield gas flows from the tip of the welding torch 9 to shield the molten pool, and the shield gas blowing holes 14 on the inner surface of the entire circumference of the support frame 3 are provided.
Then, the shield gas flows out in various directions in the shield cylinder 8 indicated by the shield gas flow direction 15, the cylinder interior is filled with the shield gas, and the surface of the welding bead 16 is completely covered with the shield gas.

At this time, when the shield gas is flowed into the shield cylinder 8 so as to have a pressurized state of 5 to 10 kg / cm ² , the shield gas passes from the inside of the shield cylinder 8 through the contact gap between the support frame 3 and the shield cylinder 8. It flows out to the outside, thereby properly preventing the air from entering the shield cylinder 8, and effectively preventing the contact of the welding bead 16 at 200 ° C. or higher with the air and the resulting oxidation.

Thus, according to this device, the effect is exhibited.

(1) A pair of half-open support frames 3 are fitted around the pipe 1 and fixed with a patch lock, and the shield tube 8 is rotatably supported by the rollers 7 between the support frames 3 and 3. It can be easily attached around the peripheral joint 2 of 1, and can be used for on-site welding.

(2) When the shield cylinder 8 is filled with the shield gas, the shield cylinder 8 shields the peripheral joint 2 with high performance while rotating following the rotation of the welding torch 9.

(3) Since the combination of the pair of half-open metal support frames 3 and the transparent glass shield cylinder 8 that is half the length corresponding to the length in the vicinity of the peripheral joint 2, the manufacturing cost is lower than that of a large chamber. And the welding work is easy.

[Effect of device]

In short, according to the present invention, a pair of ring-shaped support frames having a two-divided structure tightly fitted to the outer circumference at a proper interval with a circumferential joint of a fixed long pipe sandwiched therebetween, and both ends thereof are the above-mentioned. A transparent material shield cylinder having a vertically divided two-division structure, which is rotatably engaged with and supported by a support frame and has a hole for inserting a welding torch, and an inert shield gas provided on an outer surface of the support frame. The introduction port and the inner surface of the same frame are equipped with a large number of small-diameter blow-out holes drilled in various directions inside the shield cylinder, so that they can be easily attached to long pipes and allow the welding torch to rotate. However, because it has a high-performance shield, it can also be used for on-site welding, and since it produces a pipe welding shield device that is cheaper in manufacturing cost and easier in welding work than a large inert gas atmosphere chamber,
The present invention is extremely useful in industry.

[Brief description of drawings]

FIG. 1 shows the shield device for pipe welding of the present invention in all positions T of the pipe.
Second perspective view of the entire apparatus applied to IG welding,
The figure shows the part before assembly in the same as above. The figure (A) is a perspective view of the support frame, the figure (B) is a perspective view of the shield tube, and FIGS. 3 and 4 are partial cutaways of FIG. 1, respectively. It is a front view and a partially broken side view. FIG. 5 is a perspective view of a conventional after shield box. 1 ... Piping, 2 ... Circular joint, 3 ... Support frame, 4 ... Sponge packing, 5 ... Patch lock, 6 ... Edge, 7 ...
Roller, 7a ... Pin, 8 ... Shield cylinder, 9 ... Welding torch, 10 ... Torch hole, 11 ... Welding rod, 12 ...
... Welding rod hole, 13 ... Shield gas inlet, 14 ... Shield gas outlet, 15 ... Shield gas flow direction,
16 ... Weld beads.

Claims (1)

[Scope of utility model registration request] 1. A pair of ring-shaped support frames having a two-divided structure, which are tightly fitted to the outer periphery of a fixed long pipe sandwiching a peripheral joint with a proper spacing and a sealing material, and the support frame having both edges. And a shield tube made of a transparent material having a vertically divided two-division structure, which is rotatably engaged with and supported by and has a hole for inserting a welding torch, and an inert shield gas introduction port provided on an outer surface of the support frame. And a shield device for pipe welding, characterized in that it has a large number of small-diameter blow-out holes bored in various directions in the shield cylinder on the inner surface of the frame.