| 摘要 |
PURPOSE:To eliminate the camber of a ridge part or a plane part and to obtain parts of high processing accuracies by providing a bending process and also providing a stepping process to almost a borderline-part between a plane part and a bending part, adjoining to each other, in bending a long-sized thin plate. CONSTITUTION:A long-sized thin plate is bent, and a stepping process is also provided to the positions of almost a borderline part 11 between adjoining plane parts 9, 9' and a bending part 10. At that time, a linear, large and plastically deformed parts are created in the longitudinal directions by the stepping, and the stepped parts 11 intercept or relax a propagation of the change of internal stress caused by the bending to the plane parts 9, 9', and also serve to correct the bending angle. In this way, cambers generating at the ridge parts or the plane parts are prevented, and highly accurate parts-processing can be performed. With this method, the excellent accuracies of parts are similarly obtained even for the variance of the sheet thickness or the material quality of a plate. |
