JPH10291069A - Method and device for butt welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent penetration beads from oxidizing, and to prevent defective welding by extending and arranging a tubular body in a recessed part space along the groove direction, provided on the rear side of the parent metal of welding, and performing penetration welding while spouting out an inert gas from plural holes provided on the tubular body and filling the recessed part space with the inert gas. SOLUTION: The parent metals 6 of the butt welding are fixed through the suckers 4 of a mounting tool 1 arranged on the rear surface sides of the parent metals 6. The recessed part space 12 along a groove is provided in the center of this mounting tool 1, and further a rectangular groove 13 is recessed on the bottom surface of the recessed part space 12. By inserting a gas-supply tube 2 with plural exhaust nozzles 5 into this rectangular groove 13, and by changing over the inert gas and water through a three-way valve 10, they are made possible to be supplied. While filling the recessed part space 12 with the inert gas such as Ar, etc., to be supplied from these exhaust nozzles 5, the penetration welding is performed by using a TIG welding torch 7. Consequently, the penetration beads free from a pore, etc., caused by oxidation and with satisfactory shapes, are formed. Next, by performing regular welding while injecting the water changed over from the inert gas on a rear from the exhaust nozzles 5, the hot cracking of a weld metal 8 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for butt welding a plate-shaped base material applied to an alloy sheet such as a structural alloy or steel, and more particularly to a method for performing butt welding or manual welding of butt welding. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt welding method and apparatus for preventing oxidation of a backside bead and preventing high-temperature cracking during main welding.

[0002]

2. Description of the Related Art FIG. 3 shows the condition of a groove in butt welding and a deposited metal. Normally, when performing butt welding of an alloy plate such as a structural alloy or steel, there is no gap between the base material plate and the groove (X groove, Y, V groove) of the plate, and one-side welding is performed as it is. There are many cases, but in this case, hot cracking may occur depending on the conditions at the time of welding.

[0003] In order to solve these problems, in order to solve the problem of insufficient penetration, backside welding is performed.
As shown in FIG. 3, it is necessary to supply an appropriate inert gas 30 to prevent the oxidation of O. 7 is a TIG welding torch,
Reference numeral 8 denotes a deposited metal. In order to prevent hot cracking, it is necessary to perform welding under appropriate welding conditions while spraying water. Here, Uranami welding is a method adopted in the case of one-sided welding where it is difficult to perform double-sided welding. Before the main welding, the back side is formed on the groove bottom (having a regular waveform on the back side of the base material opposite to the electrode) The main welding is performed after performing the backside welding for forming the wave beat.

FIG. 4 shows a conventional backside welding method using a backing metal 9. According to such a conventional Uranami welding method, the Uranami welding is performed while injecting an inert gas from the TIG welding torch 7 located on the front side of the base material 6. It does not rotate, in other words, it does not become a completely inert atmosphere state, and there are cases where the shape of the backside bead 20 is defective and pores and cracks are generated due to oxidation.

[0005]

SUMMARY OF THE INVENTION According to the present invention, in order to reliably perform the butt welding of the above-mentioned alloy plates, a concave space is formed on the back surface side of the joint portion, and the Uranami bead when the Uranami welding is performed. It is an object of the present invention to provide a butt welding method and an apparatus therefor in which an inert gas flowing in order to prevent oxidation of the metal is appropriately distributed to the welded portion on the back side of the base material. Another object of the present invention is to provide a butt-welding method and a butt-welding method capable of injecting a coolant instead of the inert gas in order to prevent high-temperature cracking at the time of main welding after the above-mentioned welding. .

[0006]

As described above, when performing butt welding, a welding method using an inert gas such as TIG (Tungsten Inert Gas) welding is often employed. in this case,
The welding surface on the front side facing the welding torch is in an inert atmosphere, but on the back side of the base material of the joining surface (back side of the groove), the inert atmosphere is not completely complete yet, and the penetration is insufficient.
As described above, welding defects such as poor fusion occur.

Therefore, the invention according to claim 1 provides a recess space along the groove direction on the back side of the base material in order to prevent oxidation of the back surf bead when performing the back surf welding of the butt weld. Forming, extending and arranging a tubular body having a plurality of holes in the concave space, and injecting an inert gas from the plurality of holes in a state where the tubular body and the base material are fixed in position, and Uranami welding is performed while the inert gas is filled with the inert gas. In addition, even during the main welding after the backside welding, if the welding conditions are not appropriate, a fatal defect such as a high-temperature crack may occur in the weld metal portion subjected to the backside welding. In order to prevent high-temperature cracking during the main welding after the Uranami welding, the invention according to claim 2 performs the main welding while injecting a coolant instead of the inert gas from the plurality of holes toward the Uranami welding portion. Is performed.

According to a third aspect of the present invention, there is provided a butt welding apparatus for performing a backwash welding and a main welding, wherein an inert gas supply during the backwash welding and a water injection during the main welding are smoothly performed by the same apparatus. An invention related to a butt welding apparatus which can be fixed to the back side of the base material to form a recessed space along the groove direction of the back side, and provided on the bottom side of the recessed space and along the groove direction. It is characterized by comprising a tubular body having a plurality of holes extending therethrough, and fluid supply means for selectively supplying an inert gas and a cooling liquid to the tubular body.

According to this apparatus, for example, as shown in FIG. 1, the present apparatus is attached to the back side of an alloy plate (base material) to be welded in the welding direction by a suction cup, and the concave portion located on the back side of the base material groove. The tubular body is inserted and fixed in the space, and the inert gas is uniformly injected from the plurality of holes to the welded portion of the groove and fills the recessed space, so that the welded portion can always maintain the inert gas atmosphere. . Also, when the back welding is completed and the main welding is performed, the inert gas is switched to a coolant supply side such as water,
Hot cracking can be suppressed while cooling by spraying water. Also, by attaching a suction cup to the present apparatus, it is possible to attach and weld to a base material of any material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only. FIGS. 1 and 2 show a butt welding apparatus according to an embodiment of the present invention. FIG. 1 is a perspective view showing the apparatus configuration, and FIGS. FIGS. 3A and 3B are a perspective view and a front view showing a state in which the operation is performed. In FIG. 1, reference numeral 1 denotes a plate-shaped fixture in which two plates are superimposed and fixed, and suction cups 4 are attached to four corners on the right and left sides of the upper surface so as to be fixed on the back surface of the base material 6 (see FIG. 2). )
At the same time, a concave space 12 is formed in a band shape in the center along the groove direction (transverse direction), and a rectangular groove 13 into which an air supply pipe 2 described later can be inserted is formed in the center of the bottom surface. .
The air supply pipe 2 closes the end side thereof, and also has a large number of ejection holes 5 formed on the upper surface side of the pipe 2 corresponding to the storage space of the concave space 12, and a three-way valve 10 is attached to an inlet of the pipe 2. Water or an inert gas such as Ar or CO ₂ can be selectively introduced into the pipe 2 through the three-way valve 10 and the hoses 3a and 11a. 3 is an inert gas tank, and 11 is a faucet.

Next, an operation procedure of the apparatus will be described with reference to FIG. First, the fixture 1 is fixed to the back surface of the base material 6 by using the suction cup 4, and in this case, the center of the concave space 12 at the center coincides with the welding direction of the butted surface (groove) of the base material 6. Attach to Then, the air supply pipe 2 is inserted into the rectangular groove 13 located on the bottom surface of the concave space 12, and the ejection hole 5 is positioned upward in the concave space 12 so as to face the groove back surface. By switching the three-way valve 10 to the inert gas tank 3 side in this state, the inert gas 30 is introduced into the pipe 2 from the tank 3 via the hose 3a and the three-way valve 10, and the groove back side from the jet hole 5 The inert gas 30 is injected into the recess, and the concave space 12 is
Uranami welding can be performed in the state filled with.

When the back welding is completed and the main welding is to be performed, the three-way valve 10 is switched to the faucet 11 (water 110) side so that the water 110 is piped from the faucet via the hose 11a and the three-way valve 10. 2 and water 110 is injected from the jet hole 5 to the back side of the groove instead of the inert gas.
The main welding is performed while injecting 10. It is preferable to use a material having excellent heat resistance for the air supply pipe 2. However, if the welding conditions are adjusted and construction is performed so that the molten metal does not fall, even if ordinary carbon steel is used for the air supply pipe 2, Good.

Therefore, according to the present embodiment, since the recessed space 12 is attached in accordance with the welding (groove) direction according to the above-described configuration, the portion becomes an inert atmosphere in which no air enters. In addition, the three-way valve 10 selectively introduces the inert gas 30 and water 110 into the air supply pipe 2, and the air supply pipe 2 has a plurality of ejection holes 5 arranged in a row along the groove direction toward the welded portion 5a. Due to the perforation, an inert gas or water is selectively jetted from the jet holes 5, so that the concave space 12 always becomes an inert atmosphere or a water-cooled region,
The operation of the present invention described above is smoothly achieved. In addition, by attaching the suction cup 4 to the fixture 1, any material can be attached, and it can be effectively used even on an upward vertical surface.

[0014]

As described above, according to the present invention, in the case of uranami welding, an inert gas can be spread over the entire welded portion facing the recessed space, and welding defects due to oxidation can be prevented. In the case of welding, it is possible to perform welding while preventing hot cracking while spraying water, and furthermore, as in the above embodiment, since the mounting fixture has a suction cup, it can be attached to any material, and welding work can be performed. The range expands.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a butt welding apparatus according to an embodiment of the present invention.

FIGS. 2A and 2B show a state in which the butt welding apparatus of FIG. 1 is fixed to a back surface of a base material to perform welding, and FIG. 2A is a perspective view and FIG.
Is a front view.

FIG. 3 is an operation view showing a state of a groove in butt welding and a deposited metal.

FIG. 4 is a sectional view of a groove using a backing metal according to the prior art.

[Explanation of symbols]

1 (such as Ar CO ₂₎ fittings 2 air pipes 3 inert gas tank 4 suckers 5 inert gas injection hole 6 preform (material to be welded) 7 TIG welding torch 8 welded bi - de (deposited metal) 10 three-way valve 11 faucet (water) 12 recessed space

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masami Sawai 21-1 Minami-Asamacho, Naka-ku, Yokohama

Claims (3)

[Claims] When performing butt-welding of a butt-welded portion, a concave space is formed along a groove direction on a back surface side of a base material, and a tubular body having a plurality of holes is extended and arranged in the concave space. In a state where the position between the tubular body and the base material is fixed, an inert gas is spouted from the plurality of holes, and uranami welding is performed while filling the recessed space with the inert gas. Welding method. 2. When performing the main welding after the butt-welding of the butt-welded part, the main-welding is performed while jetting the coolant instead of the inert gas from the plurality of holes toward the uranami-welded part. 2. The butt welding method according to claim 1, wherein the butt welding is performed. 3. A butt-welding apparatus for performing back-side welding and main welding, wherein: a means fixed to the back side of the base material to form a recess space along a groove direction of the back side; A tubular body disposed and having a plurality of holes extending along a groove direction; and a fluid supply means for selectively supplying an inert gas and a coolant to the tubular body. Butt welding equipment.