| 摘要 |
PURPOSE:To improve productivity of a housing and to control working cost by forming an intermediate forged product into a housing with a small opening part formed. CONSTITUTION:A disk-shaped blank 21 is formed into a cup-shaped preliminarily forged product 31 with a bottom 33 provided partly in the axial direction by forging such as forward extrusion. The bottom 33 of this preliminarily forged product 31 is punched out to form an intermediate forged product 41 with a preliminary opening part 43 provided. A punch with the same shape as a desired inner peripheral shape is inserted from outside the preliminary opening part 43 of this intermediate forged product 41; a small opening part 52 in the inner peripheral flange shape is formed at the end 44 on the opposite side of the preliminary opening part 43; and also a housing 51 with a forged finish is formed. Consequently, since the housing 51 is formed only with a forging process, it is formed without cutting the metal flow of the housing. |
