JP2000061644A - Tig welding torch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the droop of a lower electrode in horizontal position welding of a narrow groove. SOLUTION: A dovetail groove 29 is provided on both left and right sides along the longitudinal direction of a narrow planar insulating plate 22. A belt- like electrode 23, which is dovetail-shaped corresponding to the groove 29, is fitted in each of the left and right dovetail grooves 29. An electrode structure 24', which has an overall flat cross sectional shape, is constituted through a welding wire at a position away from the electrode inserting position of the insulating plate 22. The electrode structure 24' is incorporated through a collet into the center of the torch body and projected through a gas cup.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TIG welding torch used for narrow groove welding.

[0002]

2. Description of the Related Art A conventional TIG welding torch used when a member such as a plate material is butted against each other to perform groove welding or the like is shown in FIG. The upper end of a cylindrical collet body 4 having a tapered portion 3 at the lower end is attached to the lower end of the insertion hole 2 by a screwing method, and the collet body 4 has a slit 5 in a required lower portion and a lower end. Collet body 4
Collet 6 with a tapered surface that engages with the inner surface of the tapered portion 3 of
And the tungsten electrode 7 is vertically inserted and held in the collet 6, and the lower end surface of the collet 6 is located at the upper position of the collet 6 located in the electrode insertion hole 2 of the torch body 1. The torch cap 8 is screwed so as to come into contact with the upper end surface, and by tightening the torch cap 8, the lower end portion of the collet 6 is pressed against the inner surface of the tapered portion 3 of the collet body 4 to fix the electrode 7. Further, an outer case 9 is integrally provided on the outer periphery of the lower part of the collet body 4, a gas lens 10 is attached to the lower end opening of the outer case 9, and the collet body 4 and the outer case are attached to the lower part of the torch body 1. A gas cup 11 is attached via a seal packing 11a by screwing into the outer peripheral portion of the outer case 9 so as to surround the outer body 9, and the sheet supplied to the gas supply path 12 of the torch body 1 is sealed. The Dogasu 13, collet body 4
The welding wire 14 is melted by the heat of the arc generated at the tip of the electrode 7 while being guided from the inside into the outer case 9 and discharged from the tip (lower end) of the gas cup 11 through the gas lens 10. Welding is done.

By the way, in recent years, a welding torch having a multi-electrode type electrode has been developed so that high-speed welding can be performed by allowing a large current to flow. In this case,
Since it is not possible to fix and hold a plurality of electrodes by using the collet 6 as shown in FIG.
The welding torch 20 adopts the split collet 15 as shown in (b) and (c). That is,
Two collet bodies 16 each having an arc shape are combined into a cylindrical shape, and a collet 15 having a configuration in which a tapered surface 17 is formed on the outer periphery of the lower end is formed. The electrode structure 21, which is formed by passing the welding wire 14 through the central portion of the insulating plate 19, is assembled so as to be inserted into the internal space of the collet 15. Reference numeral 4a indicates an insulator interposed in the divided portion of the collet body 4. In addition, in FIG. 4 (a) (b) (c),
The same parts as those in FIG. 3 are designated by the same reference numerals.

However, in the case of the welding torch 20 shown in FIGS. 4 (a), (b) and (c), the length of the electrode structure 21 projecting from the lower end of the gas cup 11 is set to be long so that the thick plate However, since the two electrodes 18 sandwiching the insulating plate 19 have an arc-shaped flat cross section, there is a limit in reducing the width W of the electrode structure 21 ( Even if narrow groove welding is performed, there is a limit to the applicable groove width.

Therefore, recently, as shown in FIGS. 5A and 5B, flat grooves 26 are provided along the longitudinal direction on the left and right side surfaces of the insulating plate 22 having a slender flat plate shape. Insert a strip-shaped electrode (tungsten electrode) 23,
Further, an electrode structure 24 having a flat cross-sectional shape is formed by passing the welding wire 14 at a position in the front-rear direction away from the electrode fitting position of the insulating plate 22, and the electrode structure 24 is formed.
Is held by the collet 25 having a divided structure.
An IG welding torch has been proposed. Collet 25 above
Is a circumferential four-divided structure including left and right collet bodies 25a made of an insulator and front and rear spacer bodies 25b made of an insulator so as to be interposed between the end portions of the left and right collet bodies 25a. The taper part 3 of the collet body 4
3 is formed with a tapered surface 25c for engaging with the inner surface of the torch body 1 shown in FIG.
The electrode structure 24 is screwed into the lower end of the electrode insertion hole 2 so that the electrode structure 24 projects from the gas cup 11 by a required length.

Note that the insulating plate 22 is divided into a front part and a rear part at a position where the welding wire 14 is inserted for the convenience of manufacturing.

In the case of the TIG welding torch shown in FIGS. 5 (a) and 5 (b), the welding wire 14 is connected to the electrode 23 by the electrode structure 24.
Since it has a flat cross-sectional shape so as not to pass through it, the width dimension W ′ can be reasonably made smaller than W shown in FIG. Therefore, it can be applied to the welding of a narrow groove having a narrower width.

[0008]

However, as shown in FIG.
When the narrow groove 28 formed between the thick plates 27 is laterally welded using the TIG welding torch shown in (B), as shown in FIG. 6, the tip of the electrode 23 located on the lower side is welded during welding. The part may bend under its own weight due to red heat as shown by the chain double-dashed line.

Therefore, the present invention is intended to prevent the sagging of the tip end side of the electrode in advance, and to make it possible to stably perform the narrow groove lateral welding.

[0010]

In order to solve the above-mentioned problems, the present invention provides dovetail grooves along the longitudinal direction on both left and right sides of an elongated flat plate-like insulating plate.
A configuration having an electrode structure having a flat cross-sectional shape in which strip-shaped electrodes each having a cross-section are inserted,
Alternatively, dowels are provided along the longitudinal direction on both the left and right side surfaces of the elongated flat plate-shaped insulator, and strip-shaped electrodes having grooves formed along the longitudinal direction on the inner side surface parts are fitted therein. It has a flat cross-sectional shape electrode structure.

Since the electrode is held by the insulator due to the relationship between the groove and the groove and does not separate from the insulating plate, even if the narrow groove sideways welding is performed, the sagging due to its own weight can be suppressed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show an embodiment of the present invention. In a TIG welding torch having the same structure as that shown in FIGS. 5A and 5B, an elongated flat plate is used. Instead of providing the flat grooves 26 along the longitudinal direction on both left and right side surfaces of the insulating plate 22, the dovetail groove 29 is also provided along the longitudinal direction, and the strip-shaped electrode 23 is provided with the dovetail groove 29. As the cross-sectional shape corresponding to
The electrode structure 24 'is inserted into each of the above.

When the narrow groove 28 formed between the thick plates 27 is laterally welded using the TIG welding torch of the present invention having such a structure, the electrode 23 having a cross section is fitted into the dovetail groove 29 of the insulating plate 22. Therefore, even if the lower electrode 23 is in a red hot state during welding, it does not sag under its own weight, and it is possible to stably perform narrow groove lateral welding.

Next, FIG. 2 shows another embodiment of the present invention. In the structure similar to that shown in FIGS. 5A and 5B, a long groove is formed at the bottom of the flat groove 26 of the insulating plate 22. In addition to providing the dovetail 22a along the direction, the dovetail groove 23a is provided on the inner side surface of the electrode 23, and the electrode structure 24 'is formed by fitting the dovetail 22a and the dovetail groove 23a.

Even if the electrode structure 24 'is constructed as shown in FIG. 2, the same effects as those in the embodiment shown in FIGS. 1A and 1B can be obtained.

The present invention is not limited to the above-described embodiment. For example, in the embodiment shown in FIG. 2, the flat groove 26 of the insulating plate 22 may not be necessary. Needless to say, various changes can be made without departing from the scope of the invention.

[0018]

As described above, according to the TIG welding torch of the present invention, dovetail grooves are provided along the longitudinal direction on both left and right sides of an elongated flat plate-like insulating plate, and these dovetail grooves are provided.
A configuration having an electrode structure having a flat cross-sectional shape in which strip-shaped electrodes each having a cross-section are inserted,
A flat plate is formed by arranging dowels along the longitudinal direction on both left and right side surfaces of an elongated flat plate-shaped insulator and by fitting strip-shaped electrodes with grooves formed along the longitudinal direction on the inner side surface of these. Since it has a structure with an electrode structure having a cross-sectional shape, it is possible to prevent the sagging of the lower electrode due to red heat even if narrow groove sideways welding is performed because the electrode can be reliably held by the insulator. It has the excellent effect of being able to perform welding work stably.

[Brief description of drawings]

FIG. 1 shows an embodiment of a TIG welding torch of the present invention, in which (a) is a schematic side view of the torch tip portion, (b).
[Fig. 6] is an enlarged view of the arrow (A) in the A-A direction.

FIG. 2 shows another embodiment of the present invention and is an enlarged cross-sectional view of an electrode structure.

FIG. 3 is a schematic view showing an example of a conventional TIG welding torch.

FIG. 4 shows another example of a conventional TIG welding torch, (a) is an external view of a gas cup portion, (b) is a cut-away side view of a portion holding an electrode structure, and (c) is ( It is a cutting top view of (b).

5A and 5B show an example of a TIG welding torch that has been recently proposed, in which FIG. 5A is a sectional side view of a portion holding an electrode structure, and FIG. 5B is a sectional plan view of FIG.

6 is a schematic view showing a state in which narrow groove lateral welding is performed by the TIG welding torch shown in FIG.

[Explanation of symbols]

22 Insulation plate 22a available 23 electrodes 23a Dovetail 24 'electrode structure 29 dovetail

Claims (2)

[Claims] 1. A dovetail groove is provided along the longitudinal direction on both left and right sides of an elongated flat plate-like insulating plate, and these dovetail grooves are provided with:
A TIG welding torch having an electrode structure having a flat cross-sectional shape in which strip-shaped electrodes each having a cross-section are fitted. 2. The left and right side surfaces of the elongated flat plate insulator,
In addition to providing the dovetail along the longitudinal direction, the dovetail has an electrode structure having a flat cross-sectional shape formed by fitting the strip-shaped electrodes having grooves on the inner side surface portion formed along the longitudinal direction, respectively. TIG welding torch.