1988 Volume 6 Issue 1 Pages 110-115
An experimental model of a reverse side bead width control system which employes a fiber optic thermal sensor and a microcomputer has been developed. The system is worked by monitoring infrared radiation emitted from the surface of the workpiece. In this system, a welding peak current of low frequency pulsed welding current is controlled in accordance with fluctuations in the surface temperature so as to ensure the optimum surface temperature is obtained for a high quality reverse side bead. Using this system, butt weld with groove and with gap were carried out. The fluctuations in the temperature and in the reverse side bead width were smaller when an operational gain in the welding peak current was 1 A/pulse than that was 3 A/pulse. The fluctuations of the reverse side bead width was less than ±0.5 mm at the butt weld with groove and with 0.5 mm gap.