To provide a substantially cup-shaped metallic part manufacturing method capable of reducing wear and tear of a tool, by improving a material yield by reducing cutting chips, by easily and projectingly forming a required projecting part on an inside bottom surface of a substantially cup-shaped metallic part.
This method manufactures the substantially cup-shaped metallic part 1 of forming the projecting part 2 on the inside bottom surface 1a. The method cuts a round bar-shaped metallic raw material 30 in the required length in a bulk forming process; forms a disk-like bulk 31 forming a projecting base part 32 in response to the projecting part 2; forms a projecting part element body 35 from the projecting base part 32 by being plastically processed in the next plastic working process; and forms a processing work 34 having a substantial shape approximate to the metallic part by forming the outer peripheral side in a substantially cup shape by cold forging. This processing work 34 is performed by finishing processing such as cutting work and polishing work by thinning the projecting part element body 35 and respective part surfaces such as inside-outside surfaces.
NAKAMURA KENJI
OBIKAWA KYOHIKO
