| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for stably forging a deformed bar-shaped body without die breakage or degradation of a material yield by using a preliminary expansion part at both ends of a preliminary formed body for positioning with respect to a forging die to omit the positioning by burrs. SOLUTION: In a closed die forging method of a deformed bar-like body having vertically symmetric expansion parts across the axis at least on both ends of a shaft part by using a preliminary formed body 3 of a shape close to that of the deformed bar-like body as a work, the preliminary formed body 3 is formed so that the preliminary expansion parts 10 on both ends are vertically asymmetrical across the axis L<SB>0</SB>. In the closed die forging, the preliminary formed body 3 is set to a rough forging lower die 11 so that the thickened portion 10a of the preliminary expansion parts 10 on both ends with respect to the axis L<SB>0</SB>is accommodated in an impression 12, and the cross quantityδbetween the preliminary formed body 3 and the rough forging lower die 11 is sufficiently ensured. COPYRIGHT: (C)2004,JPO
|
