| 摘要 |
PURPOSE:To obtain inexpensively a product having high accuracy by forging a blank material consisting of an annular part to be formed into a flange and a small circular cylindrical part projecting concentrically and integrally therefrom in a first stage, and providing an internal screw to the inside surface of the cylindrical part formed in a final stage. CONSTITUTION:A material W is punched by a die 10, whereby a blank material 1 consisting of an annular part 1a and a small circular cylindrical part 1b projecting concentrically and integrally therefrom is forged. The material 1 is fed to a die 11, by which a cylindrical part 2' is forged and a forged article 2 formed of a slit long hole 2c is extruded. The article 2 is fed to a die 12 by which a forged article 3 is extruded. The article 3 is then fed to a die 13, by which an end plate 4b is punched by a piercing pin 13a, and an internal screw 5 is provided on the inside peripheral surface of a cylindrical part 4a. The product having high accuracy is obtd. inexpensively by the above-mentioned method. |
