WARPAGE MEASURING METHOD OF WORKPIECE, RIGIDITY MEASURING METHOD OF WORKPIECE AND MACHINE TOOL

摘要

PROBLEM TO BE SOLVED: To provide a method which can accurately measure the warpage and rigidity of a workpiece by a simple constitution, and a machine tool which can accurately measure the warpage and rigidity of the workpiece by the simple constitution.SOLUTION: A control device 18 acquires a phase with a grinding point Pg of a point different from a grinding point Pg out of points which are located in a center on an external periphery of a workpiece W in two measurement points Pa, Pb of a sizing device 17 in a first rotation phase &thetas; as a reference as a second rotation phase &phgr;. Then, when an abrasive wheel 15 is located in a prescribed grinding command position in a constant state, the control device 18 calculates a first distance S. When the grinding point Pg of the workpiece W in the case that the abrasive wheel 15 is located in the prescribed grinding command position in the constant state rotates by the second rotation phase &phgr;, the control device 18 measures a distance between the two points Pa, PB by using the sizing device 17, and calculates a second value T which is a half of the measured distance between the two points. Then, the control device 18 estimates a difference between the first distance S and the second value T as a warpage amount &Dgr; of the workpiece W.SELECTED DRAWING: Figure 2