| 摘要 |
PROBLEM TO BE SOLVED: To provide a circularity correction method for shortening time required for correction.SOLUTION: The circularity correction method comprises an arrangement process S10 of allowing an outer peripheral surface of an inner peripheral side roller to abut on an inner peripheral surface of an axial area while opposing an inner peripheral surface of a casing to an outer peripheral surface of a pipe material and a preliminary measurement process S20 of determining a measurement outer diameter over a semicircle of the axial area by determining the measurement outer diameter while rotating the pipe material and the inner peripheral side roller around the axis and setting a load value, and repeats a correction process until both the measurement outer diameters measured over the semicircle by the preliminary measurement process or the correction process become a target outer diameter or more when regulating the correction process S40 of resetting the load value based on the measurement outer diameter, by determining the measurement outer diameter by measuring an outer diameter of the axial area, while plastically deforming a predetermined position by rotating the pipe material and the inner peripheral side roller over the semicircle of the axial area around the axis, in a state of making a load set to the predetermined position in the circumferential direction of the axial area, act on the predetermined position by approaching the inner peripheral surface of the casing and the inner peripheral side roller. |
