| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the number of welding processes and reduce the manufacturing cost of a spark plug. SOLUTION: In the laser welding process, when the number of welding points of the tip 2a and the center electrode is made N (=8) points, laser welding is made simultaneously at two points by two units of laser irradiation devices 10, 11 that are arranged at positions 180-360/N (=135) degrees slided with the tip 2a as a center. In this case, if the two laser irradiation devices 10, 11 are made as one set, and the laser welding process by two simultaneous points is made one process, after the process of odd-number times has been completed, at the next even-number times process, the welding is made at a point 180 degrees slided from the welded point made at the odd-number times process.</p> |
