Patent ID: 9421597
Filing Date: 2016-08-23
CPC Classification: B21D,B21J,B21K

Claim Text:
1. A press-work method using a press mold which includes an inner punch, an intermediate punch disposed along an outer periphery of the inner punch and having an intermediate punch inclined portion at a leading end, an outer punch disposed along an outer periphery of the intermediate punch, and a die having a die inclined portion facing the intermediate punch inclined portion, central axes of all of which are disposed coaxially, the method comprising a thickening step of, while constraining a bottom portion of a bottomed container by the inner punch and the die, pressing an end portion of the bottomed container by the outer punch and moving the intermediate punch in a direction opposite a direction in which the outer punch is pressed, to thereby thicken a bottomed container inclined portion of the bottomed container sandwiched by the intermediate punch inclined portion and the die inclined portion.