GB2240888A - Pulse welding apparatus - Google Patents

Abstract

A pulse welding apparatus such as of arc welding or short-circuiting arc welding that effects the welding utilizing pulse discharge that develops at the tip of a wire electrode, wherein undercut which is a defect in the shape of welding beads develops which deteriorates the welding when the timing for removing the molten mass grown at the tip of the wire electrode is delayed due to a change in the welding condition or disturbance. To eliminate this defect, the pulse current fed to the material to be welded is divided into a plurality of pulse groups, the pulse groups are allowed to have an average current of a maximum peak after a predetermined period of time has passed from the start of the pulse, the pulse current groups are allowed to have a mountain shape in compliance with the removing phenomenon of the molten mass, and pulse period, pulse width and pulse gap of pulse current groups are differed depending upon the wire feed speed or the pulse group period. In the short-circuiting arc welding method, furthermore, the short-circuiting and arcing periods are instantaneously controlled depending on the detected arc length or the wire feed speed to quickly obtain ideal arc length. By so doing, the molten mass can be regularly removed and moved onto the material to be welded. Even in the short-circuiting arc welding, furthermore, variation decreases between the short-circuiting period and the arcing period. Therefore, growth and removal of the molten mass can be controlled independently of the magnetic blow phenomenon of arc, and favorable welding is carried out to improve the quality irrespective of a change in the shape of welding joint and earth point in real arc.