JPH05220574A - Gas shielded torch for multiple electrode arc welding - Google Patents

Abstract

PURPOSE:To perform economical multiple electrode arc welding of high quality by providing plural torch fitting holes and many gas discharge holes on a ceiling plate of a shielding cup and using these in combination of plural torches having contact tip tilt pedestals. CONSTITUTION:Both torch main bodies 1 and the shielding cup 2 are made of a copper alloy and have paths 3 of cooling fluid. The plural fitting holes 13 for the torch main bodies and the many shielding gas discharge holes are provided on the ceramics ceiling plate 5 of the shielding cup 2. A torch holding block 6 made of insulating material incorporates a shielding gas path 7 and is fitted into the upper part of the cup 2. The contact tip tilt pedestals 14 are fitted on the torch main body 1 tips. The torch main bodies 1 are penetrated and fitted into the torch holding block 6 and the shielding cup 2 and connected to a power source and a gas supply source. A tilt angle of the plural tip tilt pedestals 14 and wire extension are adjusted and arcs are started. High efficiency is attained with multiple electrodes, the quantity of gas consumed is reduced and the quantities of spatters stuck also can be extremely reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a wide bead by a multi-electrode one-pool type gas shield arc welding method in build-up welding of a high alloy layer or high-efficiency butt welding of a high alloy clad steel, and forms a buffer. The present invention relates to a gas shield torch for multi-electrode arc welding capable of performing highly efficient welding capable of suppressing a decrease in alloy amount due to dilution of a layer or a high alloy overlay layer.

[0002]

2. Description of the Related Art In overlay welding of a high alloy layer or butt welding of a high alloy clad steel, the dilution ratio of the ordinary steel base material is reduced to suppress the decrease in the alloy amount of the high alloy buffer layer or clad layer weld metal as much as possible. A welding method is required, and conventional techniques therefor include a TIG method, a plasma method, and a method disclosed in Japanese Patent Laid-Open No. 6058/1990 by the present inventors.

Comparing the characteristics of these methods, the former two have a problem that the welding speed is low although the dilution is low.
Not suitable for high efficiency and low dilution welding. Oscillate M of the latter
Although the IG (gas shield arc) welding method has a low dilution, it has a moderate speed under practical working conditions. That is, when the groove precision is poor, it is necessary to increase the oscillating speed in order to increase the welding speed or widen the bead width. As a result, a large amount of spatter is generated, and the spatter adheres to the end of the weld bead, and it takes time to finish the grinding of the surface of the weld.

On the other hand, as a multi-electrode MIG welding method which can obtain a wide bead at a relatively high speed without oscillating, the present inventors have already disclosed it in Japanese Patent Laid-Open No. 1-87072. However, this method has room for improvement when it is used for overlay welding or welding of clad steel, which is the object of the present invention. In other words, this method is certainly capable of high-efficiency welding, but spatter is often generated, and it is difficult to weld for a long time due to clogging of spatter in the nozzle inside the gas shield box, so frequent nozzle sweeping is performed. There is a problem in that it is uneconomical to make the nozzle and shield box large and to flow a large amount of shielding gas.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides high-efficiency welding by reducing the dilution ratio of a plain steel base material in build-up welding of a high alloy layer or butt welding of a high alloy clad steel, while performing high efficiency welding. An object of the present invention is to provide a gas shield torch for multi-electrode arc welding in which the spatter clogging of the nozzle in the gas shield box (shield cup) is less likely to occur due to the shield gas.

[0006]

As a result of earnest studies on specific means for solving the above-mentioned problems, the present inventor has found that in a multi-electrode gas shielded arc welding torch comprising a torch body and a shield cup, The present invention has been completed by discovering that the above object can be achieved by the shield cup having the following features.

That is, the gas shield torch for multi-electrode arc welding according to the present invention is a multi-electrode gas shield arc welding torch comprising two or more torch bodies and a shield cup, wherein the torch body and the shield cup are copper. It is made of an alloy and has a cooling fluid passage inside, the shield cup has an opening on the work side, and a plurality of through holes for discharging shield gas perpendicular to the plate surface on the inner ceiling part opposite to the work. A detachable ceramic plate having two or more through holes for fitting the torch body and a torch body holding block made of an insulating material and having an airtightness are provided above the ceiling part, and the torch body holding block is provided downward from the through holes of the ceramic plate. Shield gas is released, and the laminar shield gas is used at the opening of the shield cup to protect the arc atmosphere at the tip of the torch body from the atmosphere and torch interruption. A gas shield torch for multi-electrode arc welding, characterized in that the two or more torch bodies preferably have contact tip slanted pedestals integrated at their respective tips to keep the distance between the consumable electrode wire tips. The gas shield torch for multi-electrode arc welding, characterized in that it is a variable type of 1 to 50 mm, and more preferably, the two or more torch bodies are vertically slidable through a through hole of a ceramic plate and contact. Insert the tip of the tip 100 mm from the bottom of the shield cup 20 mm above
The gas shield torch for multi-electrode arc welding, wherein the gas shield torch is fixed by the torch holding block within a range of mm below the double shield by releasing the shield gas from the lower end of the shield cup opening wall. The gas shield torch for multi-electrode arc welding is characterized in that it is of a shield type.

[0008]

Operation and Embodiments FIG. 1 shows an embodiment of a gas shield torch for multi-electrode arc welding according to the present invention, the main part of which is a torch body 1 and a shield cup 2. The torch body and the shield cup are made of steel alloy and have a cooling fluid passage 3 inside, the shield cup has an opening 4 on the side of the work 11 (material to be welded), and an inner ceiling portion opposite to the work. As shown in FIG. 2, a detachable ceramic plate 5 having a plurality of through holes 9 for emitting shield gas and two or more through holes 13 for fitting the torch body and an insulating material above the ceiling part are provided perpendicularly to the plate surface. The torch holding block 6 having the airtightness, which is made of, is emitted from the through hole of the ceramic plate downwardly, and the shield gas 7 is discharged downward, and the arc 8 at the tip of the torch body is radiated by the laminar shield gas at the shield cup opening. The atmosphere and the molten pool and the hot portion of the weld bead 12 can be protected from the atmosphere.

The torch body holding block 6 made of the above ceramic plate and insulating material has a long periphery closely contacting the inner wall of the shield cup, and two or more through holes 13 in the central portion closely contacting the outer wall of the torch body. Even if the gas shielded arc welding is performed for a long time, the temperature is maintained below about 100 ° C.
It is possible to electrically insulate each of the torch bodies of two or more. For that purpose, these torch bodies use independent welding power sources and wire feeders,
The welding current and arc voltage of each torch body can be set independently, and a very stable twin arc (in the case of two torch bodies) can be obtained. Further, since the temperature of the ceramic plate 5 does not rise, the shield gas discharge holes 9 of the ceramic plate will not be clogged with spatter, so that it is possible to perform multi-electrode gas shield arc welding for a long time and to shield the shield. The gas flow rate can be reduced.

Next, the two or more torch bodies can be provided with contact tip tilted pedestals 14 accumulated at their respective tips, and their tilt angles or wire extensions (distance from tip of contact tip to arc generation point). It is possible to change the distance between the electrodes (the distance between the tip of the consumable electrode wire or the arc generation point) by changing. The torch body in contact with the through hole of the ceramic plate 5 and the torch holding block 6 of the insulating material has a circular cross-sectional shape, which can be rotated at any angle and can be moved in the vertical direction. The height of the tip of the contact tip fixed to the torch body with respect to the lower end of the shield cup can be freely changed and fixed with a fixing screw (not shown) of the torch holding block.

The reason why the distance between the electrodes of the torch body is limited to the range of 1 to 50 mm is as follows. The lower limit of 1 mm is
This is because the consumable electrode wire used in the present invention is a so-called thin wire having a diameter of 1 to 2 mm, and therefore the gap between the two wires having a diameter of 1 mm is 1 mm when the wires are closest to each other. This is because there is a limit that one pool can be formed when the two wires are separated most and the large current is welded.

Further, the height of the tip of the contact tip fixed to the torch body with respect to the lower end of the shield cup is set to 20
The reason why it is limited to 100 mm to 100 mm below is that the tip of the contact tip should be retracted from the lower end of the shield cup when welding the surface layer bead on the top of the groove, but if it is retracted by 20 mm or more, the wire extension becomes too long and the arc becomes unstable. Therefore, the upper limit is set to 20 mm, and the groove depth capable of gas shielding by the shield torch of the present invention is about 10
Since it is 0 mm, the lower limit is limited to 100 mm.

Further, as shown in FIG. 1, a double shield torch can be obtained by discharging the shield gas 7'from the outer nozzle shield gas discharge hole 15 at the lower end of the shield cup opening wall.

Application Example A gas shield torch for multi-electrode arc welding as shown in FIG. 1 and Table 1 was manufactured and welded for 30 minutes to compare the welding performance with the conventional example. Table 2 shows the welding conditions and the results. It can be seen that the gas shield torch of the present invention has less adhesion of spatter inside the nozzle than the conventional one.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

As described above, according to the gas shield torch for multi-electrode arc welding of the present invention, a multi-electrode, one-pool type gas is used for build-up welding of high-alloy layers or highly efficient butt welding of high-alloy clad steel. A wide range of beads can be formed by the shield arc welding method, and high-efficiency welding is possible in which the decrease in the amount of alloy due to the dilution of the buffer layer or the high-alloy overlay layer can be suppressed as much as possible. Moreover, the example of the present invention is very economical because the flow rate of the shield gas is 1/3 to 1/5 as compared with the conventional example. Further, since the amount of spatter adhered to the torch nozzle is 1/3 or less, stable welding can be performed for a long time.

Although the twin arc gas shield welding having two electrodes has been described in the embodiment, the number of electrodes is three.
It does not matter if more than one group. Furthermore, the torch of the present invention enables high-efficiency and high-quality welding even when the welding target is not limited to high alloy steel but is applied to low alloy steel and ordinary steel.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a gas shield torch for multi-electrode arc welding of the present invention.

FIG. 2 is a diagram showing an example of the shape of a ceramic plate used in the torch of the present invention.

[Explanation of symbols]

 1 Torch body 2 Shield cup 3 Cooling fluid passage 4 Shield cup opening 5 Ceramics plate 6 Torch holding block 7 Shield gas 9 Inner nozzle Shield gas discharge port 13 Torch body through hole 14 Contact tip inclined pedestal 15 Outer nozzle Shield gas discharge port

Claims (4)

[Claims] 1. A multi-electrode gas shield arc welding torch comprising two or more torch bodies and a shield cup, wherein the torch body and the shield cup are made of copper alloy and have a cooling fluid passage therein. The cup has an opening on the work side, and the inner ceiling on the side opposite to the work has a plurality of through holes for discharging shield gas and two or more through holes for fitting the torch body perpendicular to the plate surface. Possible ceramic plate and a torch main body holding block made of an insulating material above the ceiling part and having an airtightness, the shield gas is discharged downward from the through hole of the ceramic plate, and the laminar shield is provided at the shield cup opening. A gas shield torch for multi-electrode arc welding, characterized by protecting the arc atmosphere at the tip of the torch body from the atmosphere with gas and insulating the torches. 2. The torch body having two or more torch bodies is configured such that a contact tip tilted pedestal accumulated at each tip thereof allows a distance between the tips of consumable electrode wires to be variable by 1 to 50 mm. Gas shield torch for multi-electrode arc welding. 3. Two or more torch bodies are slidable vertically in a through hole of a ceramic plate, and the tip of the contact tip is fixed by the torch holding block within a range of 20 mm above and 100 mm below the lower end of the shield cup. The gas shield torch for multi-electrode arc welding according to claim 1 or 2. 4. The gas shield torch for multi-electrode arc welding according to claim 1, wherein a shield gas is discharged from the lower end of the shield cup opening wall to form a double shield type.