| 摘要 |
PURPOSE:To smooth a flow of a metallic structure of a blank material in case of drawing, and to prevent generation of defect, by notching the surface of the blank material of a part where elongation of the blank material is large. CONSTITUTION:On a die 12, a plate-like blank material 14 is placed, pressing is executed by making a punch 10 descend, and in this case, the plate-like blank material 14 is notched 15 by a small projection 13 provided to a punch 8. Thereafter, continuously it is formed to a final shape by the remaining drawing process. When the blank material 14 is elongated by this drawing after notching, since a sectional area of the notch 15 is small, this part is naturally broken and is opened. Accordingly, a flow of the blank material in case of drawing becomes smooth, and even in case of a corner part whose drawing is difficult, the drawing is executed easily and beautifully with high accuracy. |
