| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for welding a lid and case body, which is able to prevent laser omission by shifting a gap present in the boundary between the lid and the peripheral edge part of the opening of the case body.SOLUTION: In a welding method disclosed here, a first pressing step and a second pressing step are carried out before laser welding. In the first pressing step, while a rectangular plate-like lid 20 is kept attached to the rectangular opening 31 of the case body 30, the respective central portions 32A of a pair of long sides 32 of the peripheral edges of the opening of the case body are pressed toward the lid from a sidewise direction of the case body. In the second pressing step, while the central portions are kept pressed, both side portions 32B, 32BB of the long sides adjacent to the central portions are pressed all at once, or both the side portions are divided into two or three or more portions, and they are pressed in order.SELECTED DRAWING: Figure 5 |
