PURPOSE: To improve the life of a plate shaped part high in bending stress by pressing out nearly half a part actuated by a high stress when it is used after it is worked from one side, then, pressing it back from the reverse side and pressing back this part again from one side.
CONSTITUTION: At the 1st stage, an upper press die 191 is lowered to a bias leaf spring 7 and a part for a welding small hole 21a is pressed out by an emboss pun 121a nearly half of a plate thickness. At the 2nd stage, a lower press die 102 rises simultaneously with the rise of an upper press die 101, a part 21A which is already pressed out by an emboss pin 121a is pressed out, then, pressed back nearly half a plate thickness and pushed up. In this way, the part 21A in the welding small hole 21a is cut off in the small hole 21a. At the 3rd stage, the upper press die 101 is lowered simultaneously with the fall of the lower press die 102, the part 21A in the small welding hole 21a which is already cut off is extracted by the emboss pin 121a from the inner part of the small hole 2a, dropped as scrap to form the welding small hole.
KISHIMOTO MITSURU
TATEGAMI MASAHIRO
UMEZAWA YOICHI
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