JP3700405B2 - TIG welding torch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a TIG welding torch having a multi-electrode structure.
[0002]
[Prior art]
In recent years, TIG welding torches used for groove welding by butting members such as plate materials have been developed with electrodes having a multi-electrode structure so that high-speed welding can be performed while allowing a large current to flow. ing.
[0003]
Among the TIG welding torches having the above-mentioned multi-electrode structure, those developed for narrow groove welding are shown on the left and right side surfaces of the elongated flat plate-like insulating plate 1 as shown in FIGS. The flat grooves 2 are provided along the longitudinal direction, and strip-shaped electrodes (tungsten electrodes) 3 respectively connected to different power sources are fitted into the flat grooves 2 so that the insulating plate 1 is held between the electrodes 3. And an electrode structure 5 having a flat cross-sectional shape in which the welding wire 4 is inserted into a boundary portion between the rear end surface of the insulating plate 1 and the wire guide 1a made of an insulator disposed in contact with the rear end surface. The electrode structure 5 is supported by the torch block 6, and the tip of the electrode structure 5 is projected from the tip of the gas cup 7 from which the shield gas 8 is ejected to a required length. .
[0004]
In such a TIG welding torch, it is possible to perform welding at a high welding speed while reducing excessive digging of the molten pool 9 occurring in a high current region by alternately passing a required current pulse to both electrodes 3. is there.
[0005]
[Problems to be solved by the invention]
However, in the case of the above TIG welding torch, it was developed for narrow gap welding, and in order to make the electrode structure 5 have a flat cross-sectional shape, the position of the welding wire 4 is located behind the electrode 3 from the prevention of short circuit. Therefore, the dimension between the welding wire 4 and the cathode spot 3a of the electrode 3 becomes large, so that the welding wire 4 is stabilized in the molten pool 9 formed immediately below the electrode 3. The problem is that it becomes difficult to supply.
[0006]
Therefore, the present invention is intended to stably supply a welding wire to a molten pool.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention holds the elongated flat plate-like insulating plate from both the left and right sides with strip plate-like electrodes, and inserts a welding wire at a rear position away from the electrode position of the insulating plate by a required amount. In a TIG welding torch having an electrode structure having a flat cross-sectional shape, the tip portions of both electrodes protruding from the insulating plate are cut obliquely toward the welding wire side, or the tip portions of the electrodes are sharpened. And bend to the welding wire side.
[0008]
Since the directivity of the arc emitted from the cathode spot of the electrode is obliquely rearward, the molten pool is also formed behind the position directly below the electrode, so that the welding wire can be stably supplied. become.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows an embodiment of the present invention, and as shown in FIGS. 3 (a) and 3 (b), an elongated flat plate-like insulating plate 1 is sandwiched from both left and right sides by strip plate-like electrodes 3, In addition, in a TIG welding torch having a flat cross-sectional electrode structure 5 that allows a welding wire 4 to be inserted rearward from the electrode 3 position of the insulating plate 1 by a required amount, it protrudes from the insulating plate 1. The tip portions of both electrodes 3 are obliquely cut toward the rear welding wire 4 side so that the most advanced cathode spot 3a approaches the welding wire 3. Except for the parts shown and described, the configuration is the same as that shown in FIGS.
[0011]
When the narrow gap formed between the members such as the plate material is welded, the tip of the electrode 3 is cut obliquely backward, so that the directivity of the arc emitted from the cathode spot 3a of the electrode 3 is reduced. It will turn diagonally backward. At this time, since the cathode spot 3a is closer to the welding wire 4 than in the case of FIG. 3 (a), the molten pool 9 is formed behind the position directly below the electrode 3. Thus, the welding wire 4 can be stably supplied into the molten pool 9.
[0012]
Next, FIG. 2 shows another embodiment of the present invention. In the same configuration as the TIG welding torch shown in FIG. 1, instead of cutting the tip of the electrode 3 diagonally, the electrode 3 Is sharpened and bent toward the welding wire 4 side.
[0013]
Even if it is shown in FIG. 2, the same effect as the case of embodiment of FIG. 1 can be show | played.
[0014]
In addition, this invention is not limited only to the said embodiment, The cross-sectional shape of the electrode structure 5 may be other than the shape shown in FIG. Of course, various changes can be made without departing from the scope.
[0015]
【The invention's effect】
As described above, according to the present invention, the elongated flat plate-like insulating plate is sandwiched from the left and right sides by the strip plate-like electrode, and the welding wire is inserted into the rear position away from the electrode position of the insulating plate by a required amount. In the TIG welding torch having an electrode structure having a flat cross-sectional shape thus formed, the tip portions of both electrodes protruding from the insulating plate are cut obliquely toward the welding wire side, or the tip portions of the electrodes are sharpened. Since it is configured to be bent toward the welding wire, an arc can be generated obliquely backward from the cathode point of the electrode approaching the welding wire, and a molten pool is formed behind the position directly below the electrode. Therefore, the excellent effect that the welding wire can be stably supplied to the molten pool and the welding accuracy can be improved is exhibited.
[Brief description of the drawings]
FIG. 1 is a partially enlarged view of an electrode structure showing an embodiment of a TIG welding torch according to the present invention.
FIG. 2 is a partially enlarged view of an electrode structure showing another embodiment of the present invention.
FIGS. 3A and 3B show an example of a TIG welding torch, where FIG. 3A is a schematic view of the whole, and FIG. 3B is an enlarged view taken along the AA direction of FIG.
[Explanation of symbols]
1 Insulating plate 3 Electrode 4 Welding wire 5 Electrode structure

Claims (2)

An electrode structure having a flat cross-sectional shape in which an elongated flat plate-like insulating plate is sandwiched from both left and right sides by strip plate-like electrodes, and a welding wire is inserted into a rear position away from the electrode position of the insulating plate by a required amount. A TIG welding torch having a configuration in which tip portions of both electrodes protruding from the insulating plate are cut obliquely toward the welding wire side. The TIG welding torch according to claim 1, wherein, instead of cutting the tip of the electrode obliquely, the tip of the electrode is sharpened and bent toward the welding wire.

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