| 摘要 |
PCT No. PCT/JP90/00245 Sec. 371 Date Dec. 27, 1990 Sec. 102(e) Date Dec. 27, 1990 PCT Filed Feb. 27, 1990 PCT Pub. No. WO90/09857 PCT Pub. Date Sep. 7, 1990.A pulsed arc welding for carrying out arc welding or short-circuit transfer type arc welding by utilizing the pulsed discharge generated at the tip of a wire electrode. The propensity of wire electrode curvature causes irregular changes in the contact point of the wire electrode and variations in the arc length between the wire electrode tip and workpieces. Consequently, the invention detects arc voltage and current and checks the instantaneous variation in the arc length. The arc voltage value thus detected is converted to a reference arc voltage variable. Then the detected arc voltage value is compared with the reference value to compute a true arc length. A simulation arc length signal, which varies as welding proceeds, and a reference simulation welding current waveform are set, to compare the simulation arc length signal with the computed arc length signal. The reference simulation welding current waveform is corrected according to this difference signal to form and output a welding current waveform, which is controllable instantaneously to provide an ideal target arc length. Welding can be carried out with stability since the wire electrode is allowed to hold the simulation arc length during each welding process.
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