JPH09155589A - Agitator of back shield gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently substitute residual air for a back shield gas in a short time. SOLUTION: Upper side and lower side inside tube closing partitioning plates 7, 8 made of paper are installed inside upper and lower pipings 1, 2 a gas filling space R is partitioned and formed on the back side of a joining part 5. An agitator 11 composed of a center rod 9 and an agitating vane 10 made of paper are supported freely rotating by the upper side and lower side of the inside tube closing partitioning plates 7, 8 so as to be made concentric to the upper and lower pipings 1, 2. An agitator driving wind mill 16 made of paper is attached on the central part of the center rod 9. A back shield gas G is jetted toward the agitator driving wind mill 16 from a pouring nozzle 6, the agitator 11 is rotated and the convection is generated inside the gas filling space R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer for stirring a back shield gas used when performing backside welding on a joint for butt welding pipes.

[0002]

2. Description of the Related Art When an active metal material such as titanium, stainless steel or zirconium, which is very easily oxidized, is to be joined by arc welding, an inert gas such as argon is used to shield the surface of the welding beat until it cools. In order to prevent oxidization, in particular, in the case of butt welding the pipes made of the above-mentioned active metal material, in order to form a regular wave beat (back wave beat) on the inner surface side of the joint, It is necessary to fill the back side of the joint inside the pipe with an inert gas for oxidation prevention as a back shield gas at a uniform concentration before performing back wave welding.

Conventionally, in order to butt-weld vertically arranged pipes to each other, the above-mentioned back shield gas is filled in the pipes to replace air (oxygen) in the pipes, as shown in FIG. As described above, the partition plates 3 and 4 are attached to the insides of the upper and lower pipes 1 and 2 from the joint portion 5 at a required interval, and the back shield gas G is provided on the back side of the joint portion 5.
After forming the gas filling space R for filling the groove 1, the groove 1 formed at each end of the pipes 1 and 2 on the joint 5 side.
The tip of the back shield gas G injection nozzle 6 is inserted into the gas filling space R through the gap between a and 2a, and the back shield gas G injected into the gas filling space R from the injection nozzle 6 fills the gas filling space. The residual air A in the R is expelled to the outside through the gap between the grooves 1a and 2a, so that the back shield gas G is filled in the gas filling space R at a uniform concentration.

[0004]

However, in the case of the above-mentioned conventional back shield gas filling method, the back shield gas G injected into the gas filling space R from the injection nozzle 6 simply causes the residual gas in the gas filling space R to remain. Only the air A is expelled to the outside to replace the back shield gas G with the residual air A. Moreover, as the back shield gas G, an inert gas such as argon, which has a heavier specific gravity than air, is usually used. Since it is used, the injected back shield gas G easily accumulates below the gas filling space R, and therefore the residual air A is expelled to fill the back shield gas G in the gas filling space R at a uniform concentration. In order to do so, it is necessary to continue to inject the back shield gas G, and it leaks to the outside through the gap between the groove 1a and 2a. Tsu replacement efficiency with take a long time for the click shielding amount of gas G many becomes a substituted decreases, there is a problem in that.

Therefore, the present invention is intended to provide a back shield gas agitator capable of agitating the back shield gas to efficiently replace the back shield gas with residual air in a short time. Is.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is intended for closing the upper pipe inside made of paper inside the upper and lower pipes which are concentrically arranged in the vertical direction for butt welding. A core rod made of paper by installing a partition plate and a partition plate for closing the lower pipe in a vertically symmetrical manner at a required distance from the joint to form a space for back shield gas filling on the back side of the joint. A stirrer made by attaching spiral stirring blades made of paper to the outer peripheral surface of the is housed in the gas filling space, and the upper and lower ends of the core rod are rotated to upper and lower partitioning plates for closing the pipes inside. It is supported freely, and a stirrer drive windmill made of paper is attached to the middle position of the core bar of the stirrer at the same height as the groove parts of the upper and lower pipes. A windmill for driving the agitator with back shield gas injected more It is rolling a configuration which is adapted to drive rotation of the agitator with.

A back shield gas injection nozzle is obliquely inserted into the filling space so that its tip end is directed toward the agitator driving wind turbine, and the back shield gas is jetted toward the agitator driving wind turbine. When the gas is injected into the filling space, the back shield gas is received to rotate the stirrer driving wind turbine, which causes the stirrer to rotate and generate convection in the gas filling space. As a result, the residual air in the gas filling space flows out through the gap of the groove and the injected back shield gas is also agitated, so that the back shield gas can be easily filled into the gas filling space at a uniform concentration. Can be made.

[0008] Further, when the paper for making the upper pipe closing partition plate, the lower pipe closing partition plate, the stirrer consisting of the core rod and the stirring blades and the windmill for driving the stirrer is made water-soluble, By passing water into the pipes after the welding and joining of the pipes is completed, the stirring device is completely dissolved in water, and the stirring device can be removed extremely easily.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show an embodiment of a back shield gas agitator according to the present invention. Inside the upper and lower pipes 1 and 2 which are arranged concentrically in the vertical direction,
An upper pipe closing partition plate 7 and a lower pipe closing partition plate 8 made of paper are arranged symmetrically in the vertical direction with a required space from the joint portion 5, and the upper pipe closing partition plate 7 and the lower pipe closing partition plate 7 are arranged. Attach the sleeve portions 7a and 8a extending from the outer periphery of the closing partition plate 8 to the joint portion 5 side to the inner peripheral surfaces of the upper pipe 1 and the lower pipe 2 with an adhesive or an adhesive tape over the entire periphery. The gas filling space R of the back shield gas G is defined and formed on the back side of the joint 5, and the core rod 9 made of paper in a cylindrical shape is provided inside the gas filling space R. A stirrer 11 composed of spiral stirring blades 10 each made of water-soluble paper and having a required thickness, which are attached so as to be divided into two parts, is housed on the upper end side and the lower end side of the outer peripheral surface of the core rod 9, The upper end of the core rod 9 of the stirrer 11 is connected to the partition plate 7 for closing the upper pipe. A plate-shaped bearing in which the lower end of the core rod 9 is rotatably supported by a paper-made cylindrical bearing 12 penetrating the core portion and is set on the upper surface of the central portion of the lower pipe closing partition plate 8. 13 is rotatably supported, and the core rod 9 is located at an intermediate position of the core rod 9 at the same height as the gap between the grooves 1a and 2a of the joint 5 between the upper and lower pipes 1 and 2. A circular plate 14 horizontally attached so as to be concentric with each other, and a plurality of (four in FIG. 1 (a) and (b)) wind receiving plates radially arranged at circumferentially equidistant positions of the circular plate 14. A stirrer driving wind turbine 16 composed of 15 and 15 is manufactured from paper and attached, and the back shield gas G is jetted from the tip of the back shield gas injection nozzle 6 inserted obliquely through the gap between the grooves 1a and 2a. If the stirrer drive windmill 16 is rotated Agitator 11 is rotated Te, so as to stir the gas-filled space R.

It should be noted that the upper pipe closing partition plate 7 and the lower pipe closing partition plate 8 are double-faced corrugated boards made by bonding liner paper to both sides of corrugated corrugated corrugated board. Is used so that sufficient strength for supporting the core rod 9 can be obtained.

When the back shield gas G is to be filled in the gas filling space R in order to perform the backside welding on the upper and lower pipes 1 and 2, as shown in FIG. It is inserted into the gas filling space R from an oblique direction and its tip end is directed toward the wind receiving plate 15 of the agitator driving wind turbine 16, and the back shield gas G is supplied to the agitator driving wind turbine 1.
By jetting toward the wind receiving plate 15 of 6,
The back shield gas G injected into the gas filling space R rotates the stirrer driving wind turbine 16 and at the same time, the back shield gas G is injected into the gas filling space R and the agitator 11 is rotated to rotate the gas filling space. A convection from the lower side to the upper side is generated in R, and the generated convection causes the residual air A in the gas filling space R to sequentially flow out to the outside through the gap between the groove 1a and 2a, and in the gas filling space R. Since the back shield gas G injected into the gas is agitated, the gas that tries to accumulate downward can be moved upward, and the back shield gas G is easily filled in the gas filling space R at a uniform concentration. This makes it possible to replace the residual air A in the gas filling space R with the back shield gas G efficiently in a short time. At this time, since the rotation of the stirrer driving wind turbine 16 uses the jetting force of the back shield gas G, the power for rotating the stirrer 11 can be completely eliminated, and the upper side can be used. Since the partition 7 for closing the pipe, the partition 8 for closing the lower pipe 8, the core rod 9, the stirrer 11, the bearings 12 and 13, and the windmill 16 for driving the stirrer are made of paper, the stirrer can be simplified. And it can be manufactured at very low cost.

Further, the partition plate 7 for closing the upper pipe, the partition plate 8 for closing the lower pipe, the core rod 9, the stirrer 11, and the bearing 1 are provided.
When both 2 and 13 and the agitator driving wind turbine 16 are made of water-soluble paper, water is passed into the pipes 1 and 2 after the welding and joining of the upper and lower pipes 1 and 2 is completed, The stirrer of the present invention melts and can be removed very easily.

[0014]

As described above, according to the back shield gas stirring device of the present invention, the upper pipe closing partition plate and the lower pipe closing partition plate made of paper are installed inside the upper and lower pipes. A gas filling space for the back shield gas is defined on the back side of the joining portion, and a stirrer in which a stirring blade made of paper is attached to a core rod made of paper is housed in the gas filling compartment. The core rod of the stirrer was rotatably supported by the upper and lower partition plates for closing the inside of the pipe, and a winder for driving the stirrer made of paper was attached to the intermediate position of the core rod of the stirrer, Since the back shield gas injected from the gap of the groove rotates the stirrer driving windmill to drive the stirrer, the back shield gas filling the gas filling space is driven by the stirrer. Windmill By injecting and injecting the gas toward the back shield gas, the agitator driving wind turbine is rotated by the jet power of the injected back shield gas, and the back shield gas can be injected at the same time as the agitator is driven to rotate, and the gas filling space is filled. Convection is generated inside the residual air to flow out through the gap of the groove and the injected back shield gas is also stirred, so that the back shield gas can be easily filled into the gas filling space at a uniform concentration. It is possible to efficiently replace the residual air with the back shield gas in a short time, and moreover, since the stirring device is made of paper, the stirring device can be easily and inexpensively manufactured, Furthermore, if all the members are made of water-soluble paper, the stirring device can be removed very easily by passing water through the pipes after the welding of the upper and lower pipes is completed. Kill, there is exhibited an excellent effect that.

[Brief description of the drawings]

FIG. 1 shows an outline of a back shield gas stirring device according to the present invention, in which (a) is a sectional side view, and (b) is a view taken in the direction of arrow Y-Y of (a).

FIG. 2 is a schematic view showing a conventional back shield gas filling method.

[Explanation of symbols]

 1 pipe 1a groove 2 pipe 2a groove 5 joint 7 upper pipe closing partition plate 8 lower pipe closing partition plate 9 core rod 10 stirring blade 11 stirrer 16 stirrer drive wind turbine

Claims (2)

[Claims] 1. An upper pipe closing partition plate and a lower pipe closing partition plate, which are made of paper, are provided inside the upper and lower pipes, which are concentrically arranged in the vertical direction for butt welding, at a required distance from the joint. Installed symmetrically above and below, forming a gas filling space of back shield gas on the back side of the joint, and attaching a spiral stirring blade made of paper to the outer peripheral surface of the core rod made of paper. The stirrer is housed in the gas-filled space, the upper and lower ends of the core rod are rotatably supported by the upper and lower inner partitioning partition plates, respectively, and the same as the groove parts of the upper and lower pipes. A stirrer drive windmill made of paper is attached to the middle position of the height of the stirrer core rod, and the stirrer drive windmill is rotated by the back shield gas injected from a part of the groove. Characterized by rotating the stirrer Stirrer for back shield gas. 2. An upper pipe closing partition plate, a lower pipe closing partition plate, a stirrer comprising a core rod and stirring blades, and a paper used as a material for manufacturing the stirrer driving windmill are water-soluble. The back shield gas stirring device according to 1.