Development of torch position control and welding condition control technology for all-position multi-layer GTA welding: development of full automatic GTA welding system for pipes (report 2)

摘要

Automatic control system with a laser slit sensor was developed and applied to full automatic multi-layer GTA welding for pipe joints. The laser slit sensor was able to measure dimensions of groove of the welding section. It was also able to detect the off-positioning and the groove area which required for multi-layer welding control, and the defects on the welding surface that might be in each welding pass. The dimensions of groove with hindering blocks were able to be measured. In addition, a tracking control method that was automatically corrected by following the value off-positioning of the welding torch was established. It was shown that torch position control was able to be appropriately performed at intermittently tack welding for avoid blocks, back welding of first layer and to finish welding of multi-layer. A controlling method for amount of weld deposit was useful. Using the sensor and system, It was clarified that the sound welding joint was obtained fully automatically.