JPS6163378A - Welding torch for non-consumable electrodes - Google Patents

Abstract

PURPOSE:To form exactly a penetration bead even in case of butt welding having no root gap by forming a non-consumable electrode of a welding torch to a hollow, and jetting a center gas by a necessary jet pressure from the hollow part. CONSTITUTION:As for a welding torch, a nozzle is constituted so that a center gas 6 can be jetted from a hollow part by providing a non-consumable electrode 2 can the hollow, and a regular shield gas 7 can be jetted from the periphery of the electrode 2. A butt part of materials to be welded 4, 5 is set so as to have no root gap, and when welding is started by igniting an arc 11 by the electrode 2, a part of a molten metal is extruded to the rear side of the materials 4, 5 by a jet pressure of the gas 6, and a penetration bead 10 is formed positively and exactly. In this way, in case of a butt welding having no root gap, the penetration bead can be formed exactly. This welding torch can execute melting by using oxygen as a center gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a welding torch for non-consumable electrodes.

[Conventional technology]

In butt welding, the quality of the welding is greatly influenced by whether or not the initial layer welding was performed well.

Conventionally, when performing first layer underwave welding, it is necessary to set the root gap as a setup.

Setting the gap and maintaining the gap constant in this setup work is extremely troublesome and time consuming. Moreover, the uranami pead is formed by melting and solidification due to heat transfer of the arc, and the root gap has a sharp influence on the formation of the uranami pead.

Furthermore, when cutting steel materials, a fusing device must be prepared separately from the welding machine, resulting in poor work efficiency.

[Problem that the invention seeks to solve]

The present invention aims to provide a welding torch that greatly improves the setup work before starting welding and is also capable of cutting steel materials.

[Means for solving problems]

In the present invention, the non-consumable electrode is hollow, and inert gas and oxygen gas (center gas) are spouted out from the hollow portion as appropriate depending on the situation.

[For production]

In the above configuration, if the center gas is set to the required ejection pressure,
The Uranami pead can be reliably formed without a root gap, and if oxygen is used as the center gas, fusing is also possible.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

In Figures 1 and 2, (1) is the torch nozzle, (2)
indicates a non-consumable electrode, and (3) indicates a water-cooled torch block.

As is clear from Figure 2, the non-consumable electrode (2) is hollow, and a center gas source is communicated with the electrode (2) so that center gas can be spouted from the hollow part of the non-consumable electrode (2). Make it. Also, shielding gas can be ejected from around the non-consumable electrode (2) as in conventional torches.

Next, the operation will be explained using FIGS. 3 and 4 together.

First, the materials to be welded (41(5)) are butted together as shown in FIG.

There is no need to set a root gap in this match, and the root gap may be omm.

Next, the center gas (6) is inserted from the hollow part of the non-consumable electrode (2).
, a shielding gas (71t) is ejected from around the electrode (2).The center gas (6) is an inert gas, and the ejection pressure is such that the center gas (6) is molten metal (pool) (8H9).
) can be penetrated. When the arc α sword is ignited to start welding, a pool (8) is formed by the arc heat, and a part of the pool (8) is heated to the back side of the welded material f41 (5) by the jetting pressure of the center gas (6). is extruded to form a pool (9), and furthermore a Uranami bead 00) is formed. In other words, even if the root gap is zero, the Uranami bead is 0.
0) is positively and reliably formed. Further, even if the root thickness is relatively thick, the Uranami bead 00) can be similarly obtained reliably.

Furthermore, the components of the shield gas (power and center gas (6)) may be changed.For example, if argon gas is used as the shield gas (6), and helium gas or a mixture of helium gas and argon gas is used as the center gas f6. Since the ionization voltage of helium gas is high, the same result as increasing the heat input can be obtained and the penetration depth can be increased.

In addition, when welding layers other than the first layer, if the injection pressure of the center gas (6) is lowered, the shielding gas can be fed directly to the center of the arc aυ, increasing the rolled effect and reducing the pool holding effect. You can also expect Furthermore, it goes without saying that welding similar to conventional welding can be performed by stopping the center gas.

Furthermore, fusing is also possible by heating with an arc and blowing out center gas as oxygen.

Figure 5 shows an example of the structure of the electrode. If the electrode (2) were made entirely of tungsten, it would be difficult and expensive to process, so only the tip part α2 is made of tungsten and the rest is made of copper pipe αy. This is what I did. Note that various joining methods such as brazing and screwing can be applied to the tip portion and the copper pipe.

Also, Figures 6 (a) (b) to 10 (a) (b) show various tip shapes of the non-consumable electrode (2), and the tip shape can be selected as appropriate depending on the welding conditions. Various numerical values φl, φ2.1Is12, t, and θ0, which are factors for the tip shape, are determined.

Furthermore, in addition to selecting the tip shape, the welding state can be controlled including synchronization with the mechanical on-rate by supplying center gas in pulses in synchronization with pulse control of current, welding travel, wire feeding, etc.

Figure 11 shows an example in which the electrode shown in Figure 7 is used in a narrow gap, with lI, 12, and θ variously selected, and the arc at one point of each electrode
It is possible to improve the nugget shape by adjusting the strength.

〔Effect of the invention〕

As described above, according to the present invention, the setup work before welding can be facilitated and the setup time can be significantly shortened, and furthermore, the same torch can be used for cutting, which improves the efficiency of the series of operations.

[Brief explanation of drawings]

FIG. 1 is a side view of a welding torch according to the present invention, FIG. 2 is a front bottom view of the same, FIGS. 3 and 4 are explanatory views of the operation of the present invention, and FIG.
The figure is a partial cross-sectional view showing an example of a non-consumable electrode, Figure 6 (a)
(B) to Figures 10 (A) and (B) are diagrams showing various shapes of the electrodes, and Figure 11 shows the electrodes shown in Figures 7 (A) and (B) used for narrow gap welding. It is an explanatory diagram. (2) indicates a non-consumable electrode, (6) a center gas, and (7) a shield gas. Fig. 6 Fig. 7 Fig. 8 vJ2 Fig. 9 Section 10

Claims (1)

[Claims] 1) A welding torch for a non-consumable electrode, characterized in that the non-consumable electrode is hollow and a center gas can be spouted from the hollow part.