CPC B21D 31/005 (2013.01) [B21D 24/00 (2013.01); B21D 24/005 (2013.01); B21D 53/10 (2013.01); C21D 9/40 (2013.01)] | 6 Claims |
1. A method for manufacturing a tubular rotary component from a metal disc with a hole formed in a central portion thereof, the metal disc having a predetermined inside diameter and a predetermined outside diameter, the method comprising:
an intermediate molding step comprising subjecting the metal disc to a reaming-drawing process in which both surfaces of the metal disc are pressed in entirety by a tapered surface of a punch having a predetermined taper and a tapered surface of a die having a predetermined taper, thereby producing an intermediate molded article having a frustoconical shape; and
a final molding step comprising subjecting the intermediate molded article to a further reaming-drawing process in which the intermediate molded article is pressed by a punch and a die having a smaller taper angle than the punch and the die for use in the intermediate molding step, respectively, thereby manufacturing the tubular rotary component,
wherein the final molding step is performed by inserting the punch having the smaller taper angle from a portion of the intermediate molded article having the outside diameter in a state in which a portion of the intermediate molded article having the inside diameter is positioned adjacent to the die having the smaller taper angle, and
wherein in both the intermediate molding step and the final molding step, an outer peripheral portion and an inner peripheral portion of the metal plate are subjected to shrink flange deformation and stretch flange deformation, respectively.
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