High-power double-wire pulse MIG welding low-frequency modulation type double-pulse control system

Abstract

The invention discloses a high-power double-wire pulse MIG welding low-frequency modulation type double-pulse control system. The system comprises a main engine power supply for supplying current to a front wire and cooperatively controlling the whole system, and a slave engine power supply for supplying current to a back wire, wherein a main engine and the slave engine power supply are connected through a CAN bus; the main engine power supply and the slave engine power supply respectively comprise two main circuits and control circuits; one ends of the two main circuits are connected with three-phase alternating current, and the other ends are connected with an electric arc load after parallel connection; the main circuits comprise power conversion modules; and the control circuits comprise human-computer interface modules, DSP digital cooperation control modules, high-frequency driving modules and voltage current detecting modules. The system can realize synchronous, alternating and random three types of low-frequency modulation type double pulses, and uses two ways of low-frequency modulation type double pulses of main and slave engines for acting on high-power double arcs and double-wire molten drops and causing the molten pool resonance to improve the welding process stability, to optimize the welding line structure and to improve the welding line forming quality.

Description

technical field [0001] The invention relates to the technical field of high-efficiency welding, in particular to the technical field of high-power twin-wire pulse MIG welding, and in particular to a high-power twin-wire pulse MIG welding low-frequency modulation dual-pulse control system. Background technique [0002] As an important support point for welding technology innovation, high-efficiency welding is mainly reflected in improving the deposition efficiency and improving the quality of welded joints when welding thick plates. The key to realizing high-efficiency welding is to further increase the welding current. High-power twin-wire pulse MIG welding is one of the main methods of high-efficiency welding. It has obvious advantages over traditional twin-wire pulse MIG welding. The large current output by the welding power supply (pulse peak current greater than 630A) acts on the welding wire, and the master-slave The arc will form a molten pool, and the molten droplets...

AI Technical Summary

Problems solved by technology

[0004] (1) High-power twin-wire pulse MIG welding Because the distance between the twin-wires is relatively close, if the current law in conventional twin-wire welding is applied to high-current twin-wire welding, that is, the two pulse currents of twin-wire welding are simply increased. , then the magnetic field generated by the current will increase accordingly, which will increase the interaction force of the double arcs, resulting in serious double arc interference. The process is unstable, and the ideal high-efficiency welding process cannot be realized. The welding effect is worse than the conventional twin-wire pulse MIG welding below 630A, even worse than single arc welding, and cannot reflect the advantages of high-power twin-wire welding.

[0005] (2) High-power twin-wire pulse MIG welding has a large heat input to the material, which causes coarse grains in the weld zone and heat-affected zone, which seriously reduces the toughness of the material. Some structures need to be heat treated after welding, which limits their application.

[0006] At present, there have been many researches on single-wire single-pulse welding, single-wire low-frequency modulation double-pulse welding and twin-wire single-pulse welding at home and abroad, but the research on high-power twin-wire pulse MIG welding low-frequency modulation double-pulse welding is still blank.

For example, "Technical characteristics of low-frequency modulation pulse MIG welding method" in the prior art literature (with the Red Army, Tomoyu Ueyama. Welding, 2001.11), although this welding method can obtain a beautiful fish-scale weld surface and expand the weldable joint The range of gaps can effectively suppress the occurrence of welding porosity defects, refine grains, and reduce crack sensitivity, but it is only limited to single-wire pulse MIG welding with a peak current of less than 630A, not double-wire pulse MIG welding, and its output power is much smaller than this The high-power twin-wire pulsed MIG welding used in the invention cannot achieve high-efficiency welding

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