FORMATION DEVICE FOR MATERIAL FOR FINISH FORGING OF FORGED CRANKSHAFT

摘要

A formation device moves a movable journal mold (11U 11B) toward a fixed journal mold (10U 10B) in the axial direction and moves a pin mold (12) in the same axial direction and in an eccentric direction from a state in which a rough journal section (J ) of a rough material (4) is sandwiched and held between the fixed journal mold (10U 10B) and the movable journal mold (11U 11B) and the pin mold (12) is held against a rough pin part (P ). As a result a rough crank arm part (A ) is compressed in the axial direction and the thickness thereof is reduced to the thickness of the crank arm part of a forged crankshaft and the rough pin part (P ) is compressed in the eccentric direction and the amount of eccentricity thereof is increased to the amount of eccentricity of the pin part of the forged crankshaft. Consequently it is possible to form a material for finish forging having a shape which generally matches the shape of the forged crankshaft.