| 摘要 |
PURPOSE:To improve the strength and durability of a corner construction, by previously forming a projected line along a bending line as well as forming a developed shape by removing an interfering part, and bending a composite metallic sheet along the projected part. CONSTITUTION:Projected lines 2, 3, 4, 5 are previously formed at the parts required to be bent, of a composite metallic sheet 1 by a die having a recessed groove and a punch having a projected line. Next, the parts of respective projected lines 2-5 are pressed to perform bending work while extending the metallic stock sheet 1a of one side and pressing the stock sheet 1b of the other side from its both sides into the groove. Further, the end-edge parts 2a, 3a are spreaded by removing a part 10 to eliminate an interfering part. Next, small portions of butting parts 7a, 7b are removed from dimensional lines E, F. In this way, the strength and durability of the corner construction of composite metallic sheet are improved. |
