| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a welding method for a lap joint where a gap between a plurality of joints composing a lap joint is solved or extremely reduced, and laser welding of high quality is made possible. <P>SOLUTION: Two joints 1a, 2a each composed of a steel sheet are lapped, so as to compose a lapped part 3 elongating to a belt shape. Pressure welding is performed to the thickness direction of the joints at a plurality of parts in the belt-like lapped part 3, thus a plurality of pressure-welded parts 4 with an almost rectangular shape long elongating to the width direction of the belt-like lapped part 3 are formed at intervals along the longitudinal direction of the belt-like lapped part 3. By emitting a laser beam to the belt-like lapped part 3 as scanning is performed in such a manner that the scanning line of the laser beam is crossed with each of the plurality of pressure-welded parts 4, laser welding in which a laser welding mark 5 is crossed with each of the plurality of pressure-welded parts 4 almost over the whole in the longitudinal direction of the belt-like lapped part 3 is performed. In this way, the welding of the lap joint composed of the two joints 1a, 2a is completed. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
