Arc welding device - has system for re-establishment of the arc during alternating current welding

Abstract

Abstract The arc welding device comprises a main continuous current feeder (2); a rectifier (9) for transforming the main continuous welding voltage to an alternating voltage with a low frequency rectangular wave form; an auxiliary electric feeder (22) for providing an auxiliary continuous voltage for arc re-establishment that is higher than the main continuous welding voltage; and a system (26,28,9) favouring the re-establishment of the arc applying the continuous auxiliary voltage to the rectifier (9) superposing it on the main continuous welding voltage. The arc re-establishment system includes a synchronisation mechanism (29) for limiting the application of the continuous auxiliary voltage within a time period for re-establishing the arc following a transition of a period of normal polarity to a period of inverse polarity for the welding charge. The arc re-establishment time is shorter than the period of inverse polarity. USE/ADVANTAGE - The device is used in alternating current arc welding for re-establishing the arc during the welding operation, partic. when welding easily oxidised materials such as Al. The size and weight of the system used for arc re-establishment in alternating current arc welding are decreased by reducing energy losses at the moment at which the auxiliary current is superposed on the main welding current. Excessive transient voltage produced in the rectifier by the low frequency alternating current in the auxiliary continuous current energy feed is absorbed, and the increase in auxiliary voltage following this absorption is suppressed.

Inventors

• 👤 Karino Kunio
• 👤 Fujiyoshi Toshikazu
• 👤 Danjo Kenzo
• 👤 Kinoshita Atsushi
• 👤 Moriguchi Haruo

Bibliographic Details