| 摘要 |
PURPOSE:To raise a yield of a base material by forming a band flange on the circumferential edge part of a forming base material by lower and upper blank holders, pressing and holding this flange by both holders, and press-working the base material. CONSTITUTION:A bend end part 11a is formed by bending the circumferential edge part of a flange 11 of forming base material 1 by a lower blank holder 3 and an upper blank holder 4. Also, the base material 1 is press-worked by a die 5 and a punch 6, pressing and holding the upper and lower parts of a wrinkle holding surface 12 of this bend flange 11. As a result, at the time of press- working, the base material 1 is drawn in the direction as indicated with an arrow, and prevented from flowing into the die 5. According to this method, as for the bend flange 11 part, a short length will do, therefore, a yield of the base material 1 is raised. |
