| 摘要 |
PURPOSE:To perform defectless and stable build-up welding of the inside surface of a pipe by maintaining a welding torch at a specified height, measuring an arc voltage, detecting the coincidence thereof with a reference value, upsetting the torch and profiling the end face of a bead thereby obtaining the smooth bead. CONSTITUTION:The welding torch 2 provided to the top end of a slender arm 7 is oscillated while said torch is maintained at a specified height by a suitable position detector 6 in continuous build-up welding of the inside surface of a pipe. The arc voltage VA is detected if the oscillating direction is in the direction of the build-up bead 5. The coincidence of the arc voltage with a set reference voltage Vr is detected and a command for stopping oscillation is emitted. The torch 2 is upset after time Tsec. A set oscillating width W is detected and the torch 2 is upset if the oscillating direction is on the side where there is no bead 5. Generation of an undercut or the trough in the lap part of the bead is eliminated by the above-mentioned method. |
