| 摘要 |
PURPOSE: To reduce the resistance of cooling water flow and improve joint strength. CONSTITUTION: The other strap 2 is engaged with a slit 3 of one strap 2 and the intersection part 4 is welded. The upper end of the intersection part 4 is irradiated with laser light, and a spot welding part 16 for melting a welding tab and burying each gap (c), (c) by the slit 3. Next, when an irradiating point is relatively moved along the diagonal part B1 of the intersection part 4 with the spot welding part 16 as a start point, line welding is performed, the molten part of the spot welding part 16 extends linearly, to make a line welding part 17, and a linear welding part 18 can be made by the spot welding part 16 and the line welding part 17. The line welding part 17 is made at the two opposed diagonal parts B1, B2. |
