| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for lap laser welding, by which method and apparatus, the generation of large weld cracks can be suppressed by suppressing the propagation of minute weld cracks, which are caused in a bead, in welding directions. <P>SOLUTION: A welding torch irradiates a two-plate overlapped workpiece W with a laser beam B. A welding operation is carried out while swinging the welding torch toward right and left with respect to welding direction F making the irradiation point of the workpiece W as a center. The bead 6 is varied so as to continuously change its tilting angle from a rightward tilting state 6A to a leftward tilting state 6C via a vertical state 6B in a plane perpendicular to the welding direction F, and further so as to change its tilting angle in the reversed order. Therefore, the bead 6 continues in the welding direction F while waving with a required cycle. As a result, even if minute weld cracks have been generated in the bead 6, the propagation of the weld cracks is suppressed halfway, and the minute weld cracks do not grow to large weld cracks. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
