| 摘要 |
PURPOSE:To facilitate the ejection by an ejecting device of the one piece metallic can body formed by ironing by forming numerous spot-like recessed parts of the specified size in the specified shape extending over the whole face of the side wall face of a work punch. CONSTITUTION:Numerous spot-like recessed parts 4 are formed with distribution nearly uniformly on the side wall face 1a composed of sintered hard alloy of a punch 1 and the area of each recessed part 4 is 0.03-0.8mm<2> and the depth 0.1-0.8mum, yet the percentage of the area occupied along the side wall face 1a of the recessed part 4 is preferrably to be 10-40% per unit area. The sectional shape of the recessed part 4 is preferably in radii shape or pot bottom shape and a projection part having the sectional shape corresponding nearly to the sectional shape of the recessed part 4 is formed on the body wall part 2b of the inner face of the one piece metallic can body 2 by ironing. Due to the ejection of the punch 11 from the can body formed body 2 making the recessed part 4 functional as an oil storage the sliding along the smooth part 5 of the projection part of the body 2 is smoothly performed and the ejection is bettered.
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