To enhance inner diameter accuracy of an inner circumferential surface of a cylindrical part when forming a disk-like component having a cylindrical part on its center by a rocking die forging method.
A stress which causes a material of a workpiece W flow is generated by abutting a workpiece W set in a lower mold 14 on an upper mold 12 and by pressurizing the workpiece W. The stress generated in the workpiece W at this time becomes large for approaching an end part facing the upper mold. A shape within a predetermined range of a center hole Wb in an axial direction of the workpiece W before a rocking die forging process is formed with its diameter gradually larger as it approaches the end part side facing the upper mold 12 in a state that the workpiece W is set in the lower mold 14. The shape of the workpiece W is adjusted in such a manner that as it approaches the end part side facing the upper mold 12, the material amount in the periphery of the center hole Wb is further reduced so that the material flowing to an inner circumferential surface of a cylindrical part does not become excessive. The material amount in the periphery of the center hole Wb is previously reduced so that the flowing amount does not become excessive by previously anticipating the material flowing to the inner circumferential surface of the cylindrical part.
ISHITA HIROSHI
HIRAI NAOKI
TOMIOKA AKINORI
MASUI TOSHIAKI
AOYAMA HIRONORI
| JP2006218496A | 2006-08-24 | |||
| JPH11182641A | 1999-07-06 | |||
| JP2006123890A | 2006-05-18 | |||
| JPH02151335A | 1990-06-11 | |||
| JP2005211902A | 2005-08-11 | |||
| JP2001324017A | 2001-11-22 |
Miyazaki Yoshio
Kaoru Onozuka
Akio Tagami
High Masahiro
Tsutomu Kato
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