Research Of The Double Wire AC-DC Pulsed Arc Synergic Control

After more than half a century, narrow groove welding experienced non-GMAW to GMAW development. On the current technical level, the double wire submerged arc narrow groove welding technology invented by Harbin Welding Institute was recognized by the market. Through the analysis for the narrow groove welding, we found that the double wire submerged arc narrow groove welding technology mentioned above didn't make the most of the interaction of the two arcs.According to electromagnetism and welding arc physics theory, if two close arcs are electrified the same direction current, they will be mutually attractive, if they are electrified the opposite direction current, they will be mutually repulsive. The magnitude of the attraction and the repulsion is proportional to the product of the two arcs'current, inverse ration to the distance between the two arcs and also has relative with the angle. Aimed at improving the common bad fusion of the side wall in the double wire narrow groove welding, this paper proposed to make use of the interaction of the two arcs in the double wire narrow groove welding, one arc adopted inverse DC source, another adopted AC source. Resort to the welding voltage examine circuit and pulse synergic control, when the voltage of DC source is the same direction with the voltage of AC source, the voltage is the base value, in reverse the voltage is the peak value. So the repulsion between the two arcs is the biggest while the attraction is the smallest. The attraction and repulsion between the two arcs are controlled in reason at least one wire bending, it can increase the efficiency and also improve the bad fusion of the side wall.The pulsed controller has been designed based on the existed controller and developed in combination with electronic technology, automation theory and MCU technology. The controlled is added the AC welding voltage across zero circuit to make sure the DC welding voltage variety in phase with the AC welding voltage and to control the attraction and repulsion between the two arcs. During the welding process, photoelectric signal testing and analyzing system is applied for electric signal sampling such as welding current, voltage waveform and so on. Besides, high speed photograph is used in step of electric signal sampling, to analyze the arc behavior and its effect on welding current and voltage. In conclusion, double wire AC-DC pulsed arc synergic control is novelty. The controller is easy operation and reliable to meet the requirements of the work. The study has broad prospects for application and an important theoretical and practical value.