| 摘要 |
A plurality of first projections 113a are provided in a first side wall portion 111a of a grooved section 111 formed by bending part of a sheet-like workpiece to have a U-shaped cross-section, which projections extend away from a connecting portion (top) 111c. Since the first side wall portion 111a deforms to widen a groove width of the grooved section 111 due to spring-back, a tip end of the first projection 113a is first brought into contact with the inner wall 110a. Therefore, a reaction force against the compressive force is applied to the tip end of the first projection during the pre-assembly process. Since the tip end of the first projection 113a is not movable due to the contact with the inner wall 110a, a bending moment is applied to the first side wall portion 111a and the connecting portion 111c to reduce the groove width. Accordingly, as the compression progresses, the inserting section 112 is automatically rolled in the grooved section 111 to ensure secure brazing between the grooved section 111 and the inserting section 112. |
