To properly manufacture a cylindrical body in which the thickness of a cylindrical part is thicker than that of a flange.
After pressing the base stock part 18 of the flange by the pressing surface 43 of a die 42 by the deflection of the spring of an independent suspension, when a raising and lowering plate is lowered, the small-diameter columnar part 30 of a punch 26 is fit deep into the guide hole 35 of a crushing punch 34 and the cylindrical base stock part 17 is crushed. When the raising and lowering plate is further lowered, the crushing punch 34 and the punch 26 are lowered integrally in a die hole 44 and the cylindrical base stock part 17 is pressed with the inner peripheral surface of the tapered-hole-shaped part of the die hole 44 and the outer peripheral surface of the truncated-cone-shaped part 29 of the punch 26. By setting the difference value between the inside diameter of the tapered-hole-shaped part 46 of the die hole 44 and the outside diameter of the truncated-cone-shaped part 29 of the punch 26 to the thickness of the cylindrical part of a bracket, which is a lager value than the thickness of the flange, the cylindrical base stock part 17A after press working is thickened.
COPYRIGHT: (C)2010,JPO&INPIT
WATANABE TAKASHI
MITA TOMOHIKO
MIURA TAKAHIRO
YOSHIZAWA MASAYUKI
