| 摘要 |
PURPOSE:To secure a relief and prevent a flapping, also to make a formation easy by performing a drawing after thinning with reducing the width of the deep drawn part of a metallic material. CONSTITUTION:The width of the bulging formation part 12 of the metallic material 11 cut off in a strip shape is reduced and also thinned with mechanically or hydraulically extending the bulging formation part 12 via both ends of the metallic material 11 after its being softened with heating. The housing member 16 consisting of a bulging part 14 and both end parts 15, 15 is then formed with performing a warm or cold drawing after pickling, if necessary. And after trimming the housing member 16 of which bulging part 14 is thinned and both end parts 15, 15 are thickened, a housing 17 is made with overlapping the couple thereof. |
