| 摘要 |
PURPOSE:To prevent remaining of corrective stress and generation of bending in a normalizing stage by grasping a crank shaft having the transformation temp. or above after hot forging with pressure by upper and lower plates in accordance with the target shape in the plural axial line positions and correcting the crank shaft. CONSTITUTION:Plural upper and lower plates 1a, 1b-6a, 6b provided with positioning grooves corresponding to the target shape to be set are attached to a lower base 7 in a stationary position and a vertically driven upper base 8 in such a way as to be made exchangeable in the positions of plural journal parts j1-j14 and crank parts P1, P2 along the axial line direction of a crank shaft 9. Residual corrective stress in correction is thus obviated and the generation of bending owing to the residual stress in the normalizing stage is prevented. Since there is no need for using forming dies, the correction is made possible with the inexpensive device. |
