JPH06170549A - Projection welding method and welding machine for aluminum - Google Patents

Abstract

PURPOSE:To partially remove or crush an oxide film in a welding zone. CONSTITUTION:At the time of performing projection welding of alumium, an upper electrode 2 is pressurized in low pressure to such an extent that the projection 4 shape of material 5 to be welded is not deformed. The upper electrode 2 or a lower electrode 3 is adjusted finely in an orthogonal surface direction to the pressurizing axis of the electrode, both materials 5 and 6 to be welded set on the upper and lower electrodes are rubbed mutually and the oxide film of the welding zone where both materials 5 and 6 to be welded are coming into contact with each other is partially removed or crushed. Afterward, switching is made into the normal electrode pressurizing force to perform welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum projection welding method and an aluminum projection welding machine. More specifically, it enables partial removal or crushing of an oxide film of a welded product while the welded product is set in the welder. The purpose is to stabilize the welding strength.

[0002]

2. Description of the Related Art Generally, when performing lap resistance welding of aluminum and its alloys, it is necessary to remove not only foreign matter, oil, grease, paint, dirt, etc. on the surface but also an oxide film by a proper method before welding. Is an important factor for keeping stable. Therefore, in general, after degreasing with trichlorethylene, gasoline, benzine, thinner, etc.,
The oxide film is removed by the following various methods. (A) Mechanical method: Rub the surface with a paper file or fine wire brush until you feel a strong resistance. (B) Chemical method: Chemical cleaning with industrial chemicals. However, the pretreatment means such as the above (a) and (b) is time-consuming, the number of steps is increased, and the welding cost is high. Therefore, it is necessary to remove the oxide film after being aware of the decrease in welding strength and variations. It may be welded without.

[0003]

SUMMARY OF THE INVENTION The present invention was developed in view of such circumstances, and its object is to partially form an oxide film on a welded part in a state where an object to be welded is set in a welding machine. An object of the present invention is to provide a projection welding method for aluminum and a projection welding machine for aluminum, which aims to stabilize the welding strength by crushing the oxide film while removing it.

[0004]

That is, the present invention is a projection welding method for aluminum and a welding machine therefor, wherein, when projection welding of aluminum is performed, the upper electrode is of a degree that does not deform the projection shape of the work piece. Under low pressure, finely move the upper electrode or the lower electrode in the plane direction perpendicular to the electrode's pressure axis, rub the two workpieces set on the upper and lower electrodes, and touch both workpieces. It is characterized by partially removing or crushing the oxide film of the welded part, and then switching to the regular electrode pressure and welding.

[0005]

In FIG. 1 according to the present invention, the upper electrode 2 is pressed with a pressure smaller than the pressure set as the welding condition. That is, as shown in FIG. 2, the applied pressure F1 is low enough that the protrusions 4 of the workpiece 5 set on the upper electrode 2 are not deformed. Is pressurized with. Upper electrode 2 or lower electrode 3
Is provided with a mechanism (not shown) for finely moving in a surface direction (finely moving direction shown in FIG. 1) perpendicular to the pressure axes A and B of the electrodes. The fine movement method includes a linear reciprocating motion mechanism and a rotary reciprocating motion mechanism. And the upper electrode 2 or the lower electrode 3
Is finely moved in a plane direction perpendicular to the pressure axes A and B of the electrodes, and then the work piece 5 on which the projections 4 for fitting and fixing the guides 2a and 2b of the upper electrode 2 are processed, and the lower part. The object 6 to be welded set on the electrode 3 is rubbed between S and T shown in FIG. 2 to crush the oxide film in the portion where both objects 5 and 6 to be welded are crushed. Electrode pressure F2 when welding shown Switch to and weld. In Fig. 2, IW
Indicates welding current.

[0006]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a projection welding machine for carrying out the method of the present invention, and FIG. 2 shows an operation sequence. The projection welder 1 comprises an upper electrode 2 and a lower electrode 3,
The upper electrode 2 fixes the guides 2a and 2b, and
In a and 2b, the work piece 5 provided with the protrusion 4 is fitted and set, and the lower electrode 3 sets the work piece 6 to be welded. As shown in FIG. Weld 6 together. Reference numerals A and B in FIG. 1 indicate the pressure axes of the electrodes, and reference numerals a and b indicate the directions in which either the upper electrode 2 or the lower electrode 3 slightly moves. In FIG. 1, the bent portions of the guides 2a, 2b fixed to the upper electrode 2 and the welded object 6 set on the lower electrode 3 are the upper and lower welded objects 5, 5 when the electrodes slightly move in the a and b directions. Reference numeral 6 is a means for preventing displacement from the respective electrodes, and it is conceivable to prevent displacement by using, for example, a figure electrode or a guide pin.

[0007]

EFFECTS OF THE INVENTION According to the above construction, the oxide film of the object to be welded (aluminum) can be crushed while being partially removed immediately before the welding current is applied, so that the welding strength is stable and the oxidation is stable. Welding strength is improved compared to the case where the film is not removed, and there is less variation in welding, and further oxide film removal treatment is possible compared to conventional mechanical method oxide film removal and chemical method oxide film removal. It is simple and, in combination with the stable welding strength, the workability of aluminum projection welding can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a projection welding machine.

FIG. 2 shows an operation sequence.

[Explanation of symbols]

1 Projection Welder 2 Upper Electrode 2a Guide 2b Guide 3 Lower Electrode 4 Projection 5 Welding Object 6 Welding Object A, B Electrode Pressing Axis a, b Electrode Fine Moving Direction F1 Low electrode pressure so that the protrusion does not deform F2 Electrode pressure when welding IW Welding current

Claims (2)

[Claims] 1. When performing an aluminum projection welding method, the upper electrode is pressed under a low pressure that does not deform the projection shape of the object to be welded, and the upper electrode or the lower electrode is perpendicular to the pressing axis of the electrode. To be slightly moved in the direction of the surface to be rubbed, and the objects to be welded set between the upper and lower electrodes are rubbed against each other to partially remove or crush the oxide film of the welded part in contact with the objects to be welded. After that, the aluminum projection welding method is characterized in that the welding pressure is changed to a regular welding pressure. 2. The aluminum projection welding machine according to claim 1, wherein the upper electrode or the lower electrode is provided with a linear reciprocating mechanism or a rotary reciprocating mechanism which is finely moved in a plane direction perpendicular to the pressure axis of the electrode.