| 摘要 |
PROBLEM TO BE SOLVED: To provide a forming means capable of performing the shell press forming for manufacturing a can lid provided with a stepped chuck wall 4 having a lower wall part 4a of a gentle slope and an upper wall part 4b of a steep slope via bent part 4c of an intermediate portion in the height direction with high efficiency without causing any squeezing wrinkle or breakage, by the forming operation of one process. SOLUTION: A press die is used, which has an inner pressure sleeve 22 on a punch unit 20 side for forming a chuck wall 4 as an independent elevating/lowering one to be elastically urged in a constantly downward direction by a cushion means 25. The chuck wall 4 is preliminarily formed on a forming blank 1A with the elastic urging force downward of the inner pressure sleeve 22 being as a punching force. While elastically pressing the formed chuck wall 4 from an upper side by the inner pressure sleeve 22, a strengthened annular groove 3 is formed by deep-draw in a state in which the chuck wall is allowed to function as a wrinkle holder. COPYRIGHT: (C)2009,JPO&INPIT
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