JPS5861966A - Welding method for work - Google Patents

Abstract

PURPOSE:To make the generation of arcs quick and sure by changing over short arc welding to pulse arc welding in the stages of starting and ending of said welding and applying a high frequency voltage between a wire and the arc prior to the pulse arc welding in the stage of starting. CONSTITUTION:A wire 1 is fed continuously, and short circuiting and arcing are repeated alternately between the wire and the work, whereby the work is subjected to welding of a short arc type. In the stage of starting and ending of said short arc welding, the welding is changed over to the pulse arc welding by the welding currents 4, 5 wherein pulse currents are superposed on base current. further, prior to the pulse arc welding in the stage of starting, a high frequency voltage 6 is applied between the wire 1 and the work, so that an arc is induced between the wire and the arc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding method mainly applied to workpieces made of thin plate materials.

Conventionally, one method of welding is to continuously feed a wire and alternately short circuit and arc between the workpiece and the O-gate, thereby welding the workpiece to the O-to-Ata weld. It is well known that the changes in welding current and wire feeding speed in this case are as shown by & and 1 in FIG. Unstable phenomena such as the wire thrusting or the generation of large spatters due to the start-up delay occur, which tends to result in insufficient penetration of the weld at the starting end of the weld. Possible causes include the formation of a welded part d at the tip of the wire as shown in Figure 2, and insufficient heat input at the starting end of the welded part. It is known that the current at the start is increased to create a new hot starch type, as shown by the dotted line in the figure. Formulas that give stick current g are known, but they do not always give good results.

The purpose of the present invention is to provide a method that does not cause such inconveniences, and it involves continuously feeding a wire and alternately causing a short circuit and an arc between the wire and the workpiece. In the required type, the workpiece is subjected to arc welding at the start and end of the arc welding, and the arc welding is switched to pulse arc welding at the start and end of the arc welding, and Prior to pulse arc welding, a high frequency voltage is applied between the wire and the workpiece to
K is used to wake up t-S.

An example of implementing the present invention will be explained with reference to the attached drawings.

By continuously feeding the wire (1) and alternately repeating short circuits and arcs between the wire (1) and the workpiece, short arc welding is performed on the workpiece, which is different from conventional welding. The welding current is, for example, shown by m (2) in FIG. At the beginning and end of starvation arc melting,
Pace current K/<9 welding current (4)
(6) Switch to pulsed arc welding by KL
Further, prior to the initial cough pulse arter melting 1', a high frequency voltage (6) was applied between the wire +11 and the workpiece to induce an arc thereon.

To explain further, according to the welding start command, feeding of the wire +11 is started, and at this time, a high frequency voltage (6) is applied between the wire (11) and the workpiece facing it,
An ionized atmosphere is thus formed between the two parts, and an arc is generated relatively quickly.

Next, at the same time as the arc is generated, a pulsed welding current (4)
・In this case, the maximum current value is 1180 μm, and the time is about 0.4 seconds. ・This gives sufficient heat input to the workpiece, so next we will increase the current (2). Switch to short arc type contact. In this case, the current is, for example, 160 μm. Next, when welding is finished, the welding current is lowered a little (2) and a pulse is superimposed on this to produce pulsed arc welding using a pulsed type electric current U5) to perform crater treatment.

In this case, the maximum current value is, for example, 90 μm and the time is about 0.4 seconds, and then the current is further lowered and the process ends after about 0.1 seconds. Thus, when welding is completed, pulse arc welding is performed, and a relatively large pinch force acts on the tip (7) of the wire (1), which transfers to the workpiece side, causing the tip (7) to become a K molten ball. The state m is, for example, the through hole shown in FIG. 4, which is advantageous for improving the starting characteristics when starting welding by the line method.

As described above, according to the present invention, when starting welding, a high frequency voltage is applied between the wire and the workpiece, so that the arc can be generated quickly and accurately, and furthermore, as the arc is generated, pulse arc welding This method allows sufficient heat input to be obtained at the beginning of the weld and there is no lack of penetration.
Furthermore, at the final TK of short arc welding, pulse arc welding is performed again, which eliminates the generation of molten balls at the tip of the workpiece. Together, this has the effect of greatly improving the starting characteristics when starting subsequent work.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the operating characteristics of the conventional example, Fig. 2 is a diagram 111 explaining the tip of the wire at the end of the process, and Fig. 5 is an explanatory diagram of the operating characteristics of an example of the method of the present invention. FIG. 4 is an explanatory diagram of the tip of the wire at the end of the process. +11...Wire (2;...Short arc welding current (31...Wire feeding speed +43 (51...Pulse arc welding current (6)...
・・・・・・2 people outside of Takatonami Voltage

Claims (1)

[Claims] In a type of wire that is continuously fed and alternately short-circuited and arced in relation to the workpiece, a short arc* is applied to the workpiece. The arc welding is switched to pulsed 7-ta welding at the start and end of the arc welding, and a high pigeon wave voltage is applied between the wire and the workpiece prior to the pulsed arc welding at the start. A method of welding a sorter by inducing an arc.