JPS5838663A - Tig arc spot welding device - Google Patents

Abstract

PURPOSE:To facilitate welding of aluminum sheet materials of different thicknesses in a TIG arc spot welding device by projecting notched parts for discharging a shielding gas for welding on the inner side in the preceding end part of a gas cup. CONSTITUTION:When a welding signal is applied, a shielding gas ejects through the small hole 4a of a collet 4, flows along the inner side surface of a gas cup 15, and flows out through notched parts 15a to the outside. At the same time, an arc is generated between a tungsten electrode 3 and an aluminum sheet material 1. At this time, the sheet material 1 expands by the effect of heating and the part where the arc is generated tries to float up but the material 1 is pressed to an aluminum bar 2 by the projecting parts 15b of the cup 15. Therefore, the floating of the sheet 1 is suppressed, said material is melted to one body with the aluminum bar 2 by receiving the integrated thermal effect, whereby the welding is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a WIQ arc spot welding device suitable for overlapping spot welding of materials to be welded such as aluminum sheet materials, and is particularly aimed at customers for welding aluminum sheet materials of different thicknesses. The present invention relates to a TIG arc spot welding device that can perform TIG arc spot welding.

BACKGROUND ART Conventionally, aluminum sheets have been widely used for the windings of electric machines, such as transformers, due to their electrical properties and economic efficiency.

In order to form an electric circuit, the winding wire using this aluminum sheet is always connected to an aluminum strip or steel strip called a lead conductor.

For aluminum strips, overlap the aluminum sheet and aluminum strip,
IQ welding method, MIG, which involves cold pressure welding by applying strong pressure to the contact surfaces, or fusion welding of the overlapped ends.
Welding methods are used. TIQ welding in this? 1i
Since IG welding continuously welds the end faces of overlapping aluminum sheets and aluminum strips, a device is required to tighten and fix the aluminum sheets and aluminum strips in a stacked state, and the setup work for this is complicated. Similarly, in cold pressure welding, the pressure welding device is of a stationary type, and therefore it is laborious to set up the work when moving from the work of winding the aluminum sheets to the work of connecting the aluminum foil conductors.

For these reasons, TIG, which is easy to handle, has recently become available.
TIG arc spot welding with a welding torch tends to be used. TIG arc spot welding uses AC T as shown in Figure 1.
Connect the aluminum sheet material l and the aluminum strip 2, which are the materials to be welded, to one output terminal of the IG welding machine in a stacked manner, and connect the collet 4 that supplies power to the tungsten electrode rod 1 to the other output terminal of the welding machine. . Here, the collet 4 holds the tungsten electrode rod 3 and has a small hole 4m in the middle part for blowing out welding shield gas. Also tungsten 2,
A gas cup 5 is provided on the outside of the electrode 3 to maintain the tungsten electrode 3 at an appropriate distance from the aluminum sheet material I, for example, at a distance equal to or less than the diameter of the tungsten electrode rod 3, and to isolate the welded portion from the outside air. This gas cup 5 has a notch 5 at its tip for allowing the welding shield gas to flow out, and is attached to the welding torch body together with the collet 4 via an insulating cylinder 6. In this state, when a welding signal is input, welding shield gas is ejected from the small hole 41 and flows through the notch 5a, and at the same time a welding arc is generated between the tungsten electrode rod 1 and the aluminum sheet material l, and the aluminum sheet Material I
is melted, a small hole is made in the aluminum sheet material 1 by the arc airflow, the aluminum strip 2 is exposed, and an arc is generated thereon.

If the thickness of the aluminum strip 2 is similar to or not extremely thick compared to the thickness of the aluminum sheet material I, the aluminum strip 2 will begin to melt immediately after the arc transfers to the aluminum strip 2, and the aluminum strip 2 that has already been formed will begin to melt. It comes into contact with the molten metal of the sheet material I to form the same molten pool and become integrated. However, if the thickness of the aluminum strip is extremely thick (several times or more than the thickness of the aluminum sheet material I), after the aluminum sheet material I melts and penetrates, the aluminum strip 2
Even if the arc moves to , since the heat capacity of the aluminum strip 2 is large and it takes time to melt, the aluminum sheet material 1 will continue to melt due to the indirect heat of the arc, and the diameter of the through hole in the aluminum sheet material 1 will increase. . Therefore, the molten metal of the aluminum sheet material I does not come into contact with the molten metal of the aluminum strip 2, making welding impossible.

An object of the present invention is to provide a TIG arc spot welding apparatus that can easily weld even when the thickness of the welded materials differs widely as described above.

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure and Fig. 3, an aluminum sheet material 1 and an aluminum strip 2 with a larger thickness are overlapped and intersected.
Connect to one output terminal of the welding machine. A tungsten electrode S is held in a collet 4 having a small hole of 4 m at an appropriate distance from these materials to be welded, and is connected to the output terminal of the welding machine O through the collet 4 to form a welding circuit. The Dungesten electrode 3 and collet 4 are attached to the welding torch body. Further, a gas cup 15 is attached to the welding torch body via an insulating tube 6, which maintains the distance between the tungsten electrode rod 3 and the aluminum sheet material l, which is the welding material, to an appropriate dimension, for example, less than the diameter of the tungsten electrode 1. . A protrusion tsb that protrudes inward is formed at the tip of the gas cup 15, and a plurality of notches ISm for shielding gas outflow are formed in the radial direction. The material of the gas cup 15 is preferably a heat conductive material such as steel or steel alloy. In addition, the inner diameter of the protrusion 16b needs to be smaller when the thickness of the aluminum sheet material l is small, but it is preferably about 5 to 10 times the thickness of the aluminum sheet l, so that the arc does not fly to the protrusion ISb of the gas cup 15. is the limit.

In such a configuration, when a welding signal is applied, the shielding gas for insulating the welding part from the outside air is ejected from the small hole 4 of the collet 4, flows along the inner surface of the gas cup 15, and flows to the outside from the notch Hx5m. Simultaneously with the outflow, an arc is generated between the tungsten electrode 3 and the aluminum sheet material 2.

At this time, the aluminum sheet material 1 expands due to the heating of the arc, and the arc generation area tends to rise locally, but the protrusion W61 Sb of the gas cup 15 prevents the aluminum sheet material 1 from being pushed up to the vicinity of the arc generation area. Since the aluminum sheet material 1 is pressed against the aluminum strip 2, lifting is suppressed,
The aluminum sheet material 1 and the aluminum strip 2 are thermally connected.

Heat is also radiated to the gas cup 15 through the contact portion with the aluminum sheet material 1.

Therefore, the aluminum sheet material I and the aluminum strip 2 are thermally acted as one body, and it is unlikely that only the aluminum sheet material I will overheat, and the aluminum sheet material I and the aluminum strip 2 directly under the arc will be in the same state. They are heated to melt and integrate, completing welding. Even if the aluminum sheet material l overheats and a through hole occurs, the aluminum sheet material l of the gas cup 15
The effect of heat dissipation from the contact surface works to prevent large holes from forming. After the through hole is formed, the arc moves to the aluminum strip 2,
The molten metal of the aluminum strip 2 is generated and comes into contact with the molten metal of the aluminum sheet material L existing around the through hole of the aluminum sheet material 1, and the molten metal of the aluminum strip 2 and the aluminum sheet material 1 are integrated to complete welding. . Also, the protrusion 15 of the gas cup 15
Since the air flow along b approaches the arc, it has the effect of forcibly cooling the arc directly. For this reason, the expansion of the arc is suppressed, and the concentration of the arc is reduced to the east.
Aluminum Seat F Material 11 The effect of local heating on the aluminum strip 2 is greater, so the effect of enlarging the through hole in the aluminum sheet material I is also reduced, and the melting depth of the aluminum strip 2 is also increased, which helps welding. .

As described above, according to the present invention, it is easy to thermally integrate the members to be welded, so it is not only possible to weld together aluminum sheet materials of the same thickness, but also to weld them together with extremely thick sheets, which was previously difficult. It is possible to carry out spot welding using a τ■G arc in lap joints of different aluminum materials. By eliminating the restriction on the plate thickness of the aluminum exposed conductor in TIG arc spot welding, the degree of freedom in the design of electric machines is improved, making it possible to utilize materials, for example, and in terms of machining, the conventional end face T
It is possible to provide a TIG arc spot welding device that does not require reliance on IG continuous welding and can be used as a joint that is advantageous in terms of workability and economy.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional TIG arc spot welding device;
FIG. 2 is a sectional view showing a TIG arc spot welding apparatus according to an embodiment of the present invention, and FIG. 3 is a bottom view of a gas cup. l...aluminum sheet material, 2...aluminum strip, 3...
Tanksten electrode, 4...collet, 5.15...
Gas cup, 5a, l15 [...notch, 15b...
・Protrusion. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] A tungsten electrode that generates an arc between the material to be welded, a collet that holds the tungsten electrode, supplies power to the tungsten electrode, and has a small hole for ejecting welding shield gas, and a welding device to which the collet and tungsten electrode are attached. It is attached to the torch body via an insulating cylinder, has a size that allows the tip to closely contact the material to be welded and maintain the tungsten electrode at an appropriate distance from the material to be welded, and discharges welding shield gas from the tip. A TIG arc spot welding device comprising: a gas cup having a protrusion that centrally projects a cutout portion inward;