Detection And Anlysis Of Penetration Control Information In Plasma Welding

According to valuable achievements and experiences for many years, the stability of the keyhole plays an important role on the welding stability and joint quality. Therefore, the control of the keyhole in real-time can be gotten by means of detecting the state of the keyhole during keyhole plasma arc welding, it is a short cut to improve the welding quality in the research field of plasma arc welding.The paper did photograph to keyhole plasma arc welding, we can easily see the change state between the plasma cloud and keyhole. In addition, we draw a conclusion that plasma cloud is the feature of the keyhole by the analysis to the mechanics of forming plasma cloud and the change rule of plasma cloud. In order to control the penetration of plasma arc welding effectively, this paper has provided a new method of detecting plasma cloud without power as well as corresponding device, a dynamic scanning machine is designed to find the optimal position of detecting plasma cloud, which ensures detecting plasma cloud effectively and accurately. The change of keyhole has periodic law, And the period is 10ms in the test condition, corresponding change of the plasma cloud is the same. The peak time is 4ms, and the backhand time is 6ms. Therefore, the period, the peak time, and the backhand time are all the character of the keyhole in the penetration control of plasma arc.At last, this paper realizes the detect and penetration control of plasma arc welding by acquiring voltage signal of plasma cloud, and the reality must be on the basis of two voltages, one is in stable welding process, the other is in unstable welding process. It is verified experimentally that the new method is sample, accurate and effective in the penetration control of plasma arc welding.