| 摘要 |
PURPOSE:To prevent generation of deformation caused by working such as warping, etc. and to stabilize the dimensional accuracy of side walls by forming a joggle on at least one face of thin steel sheet to be press-formed. CONSTITUTION:A curved upper face is formed by drawing a thin steel sheet, and holes 4 are formed by piercing. After forming a joggle 5, the side wall 9 is bent in the direction of the arrow 6 to a position 7. By forming above-mentioned joggle 5, excess of material caused by drawing work is abosrbed and a hardened line generated at boundary between the drawing work and bending work of the side wall 9 is also absorbed. Thus, generation of waving, warping, deformation of holes, etc. are prevented, the rigidity of the side wall 9 is increased and the dimensional accuracy is stabilized. It is desirable to form the joggle nearly straight in the longitudinal direction of the product and at a place between the line hardened by drawing work and holes 4. |
