METHOD AND EQUIPMENT FOR BUTT LASER WELDING OF TUBE

PURPOSE:To automatically execute the butt welding of a tube along the butted part with fixing the attitude of tube by butting end faces of tubes and simultane ously laser welding the butted part from both the inside and outside of the tube. CONSTITUTION:A reflection mirror 12 is arranged at the joint part of a duct 4, laser beam is transmitted as parallel beam in a main arm 1. Next, the laser beam is distributed to an inside sub-arm 7 and outside sub-arm 10 by a half mirror 13 arranged at a branching part 9. One of the laser beam is transmitted into the inside sub-arm by a reflection mirror 14 arranged at the joint part between a main arm 1 and inside sub-arm 7. Further, it is transmitted to a collective mirror 16 by a reflection mirror 15, a butted part 2c of tube inside face is irradiated with the collected laser beam from a nozzle 8. Other laser beam is transmitted into the inside sub-arm 7 by a reflecting mirror 17 and is led a collective mirror, the butted part 2c of tube outside is irradiated with the collected laser beam from a nozzle 11. Deep penetration welding becomes possible with the tube fixed.