| 摘要 |
PURPOSE:To prevent breakage of material due to working by forming a disk- shaped metallic blank into bottomed cylindrical form that has larger outer diameter than that of a product and reducing the outer diameter to that of the product by applying force from the side of opening. CONSTITUTION:A disk-shaped metallic blank of thickness t0 and diameter d0 is set on a conical guide in the upper part of a die 2, and pressed from above by a punch 4 to form a primary work 6 having outer diameter d1. The outer diameter d1 is restricted to 0.0015 times the diameter d0. Then, it is set on the upper part of a die having diameter equal to the outer diameter d1 of the primary work 6, and pressed by a pusher 9 having nearly the same diameter with the large diameter part of the die from the side end face of the opening and pushed in to the middle of the die hole 11 having the same diameter with outer diameter D of the product. After that, the pusher 9 is replaced by a pusher 9' having nearly the same diameter D with the die hole 11, and pushed to the lower part of the die hole 11. By this way, a product of t/d>=0.5, h/d>=1 is manufactured safely and efficiently. |
