| 摘要 |
FIELD: technological processes.SUBSTANCE: group of inventions relates to welding equipment, namely, to the method and source of power supply for electric arc welding by a three-phase arc. The source of power supply comprises a control unit made in the form of a microprocessor, and three circuits, each of circuits comprising serially connected a rectifier and an inverter, and they are made as capable of connection by the inlet with the source of energy. Each circuit is connected with a high-frequency transformer connected to the appropriate secondary circuit. Each secondary circuit comprises a rectifier, a throttle and an inverter. Outlets of inverters of secondary circuits are connected as "delta" being capable of connection with the welding circuit, which comprises two electrodes and a welded item. Each inverter of the secondary circuit is made as capable of producing square current pulses, of adjustable frequency and amplitude, and connection and disconnection at the required moment of time and generation of a pulse of necessary polarity. Welding is carried out in inert gas medium using two dependent arcs between the item and each of non-melting electrodes and one independent arc between non-melting AC electrodes, which supply power from a separate phase of three-phase current. At each moment of time they provide for burning of at least two arcs. Dependent arcs are fed with phase currents, having the shape of square pulses of direct and reversed polarity of adjustable frequency and amplitude.EFFECT: increased efficiency of the method.5 cl, 2 dwg, 1 ex |
