| 摘要 |
PROBLEM TO BE SOLVED: To reduce blowholes generating in welding, in the manner suitable for mass production while damage to a steel sheet is controlled, by vibrating the steel sheet at the time when two or more steel sheets including at least one surface treated steel sheet are lap-welded or fillet-welded. SOLUTION: Two steel sheets 1a, 1b are tightly superposed with the ends fixed by a clamp base 5, and welded at a position about 5 mm from the end of the opposite side of the fixed end, by means of CO2 gas laser provided with a welding nozzle 2, under prescribed welding conditions while focussing on the surface of the steel sheet 1a. In this case, a vibrating device 3 constituted of a motor and a cam mechanism is brought into contact with the steel sheet 1a at 50 mm forward in the welding direction from the welding nozzle 2 and vibrated. The displacement of the steel sheets 1a, 1b is measured by laser displacement gauges 4a, 4b, which are installed holding the steel sheets 1a, 1b in-between in front of the welding nozzle 2, the measurement is converted into a gap between the steel sheets. The conditions of the vibration are desirably set so that a gap of >=0.05 mm in amplitude is formed in the weld zone. |
