Circuit for realizing CO2/MAG (metal, active gas welding) arc welding machine arc-striking method

Abstract

The invention relates to a circuit for realizing CO2 / MAG (metal, active gas welding) arc welding machine arc-striking method. The circuit comprises an arc welding machine main circuit which includes a step-down transformer and a direct current reactor. A third thyristor group is arranged on the secondary winding of the step-down transformer, one end of the direct current reactor is connected with the anode end of each thyristor in the third thyristor group and the third thyristor group is connected with the output end of a thyristor control circuit. In arc striking, the thyristor control circuit outputs a first control signal, so that the direct current reactor is formed as an arc striking bypass by the arc welding machine main circuit via the third thyristor group, and arc striking is performed by the secondary winding of the step-down transformer until arc striking is finished. After arc striking is finished, the thyristor control circuit outputs a second control signal, so that the direct current circuit output from the step-down transformer turns off the third thyristor group and required welding is performed by the direct current reactor. The inventive circuit is simple in structure, improves welding machine arc striking success rate, causes small welding splash, realizes good formed weld seam, and is convenient to operate, safe and reliable.

Description

technical field [0001] The present invention relates to a kind of circuit structure, especially a kind of realization CO 2 A circuit for the arc striking method of a MAG arc welding machine belongs to the technical field of welding technology and electronic control. Background technique [0002] CO 2 / MAG (Metal, Active Gas Welding) MIG welding machine is a high-efficiency and energy-saving welding method, which is widely used in welding various metal materials. Currently CO 2 Most / MAG arc welding machines adopt thyristor control mode, and the adjustment and control of the output arc voltage is simple and reliable. CO 2 / MAG arc welding machine The success rate of arc ignition is an important performance index of the welding machine. CO 2 / MAG arc welding machine welding is in a short-circuit transition state. Usually, in order to limit the rising rate of the short-circuit current, a DC reactor is added to the rectification output circuit to improve the dynamic respon...

AI Technical Summary

Problems solved by technology

In conventional thyristor controlled CO 2 In the / MAG arc welding machine circuit, an output DC reactor is added to limit CO 2 During the dynamic welding process of / MAG arc welding machine, the short-circuit current rising rate di / dt makes the welding spatter small and the weld shape is good during the welding process. Arc ignition is easy to achieve success

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