Patent ID: 7037248
Filing Date: 2006-05-02
Classification: B23Q,Y10T

Abstract:
1. A machine tool in which a tool holder attached with a tool and having a flange on which a notch is formed is mounted on a main spindle and which performs rotational driving of the main spindle to machine a work, the machine tool comprising: a non-contact type measuring device which measures a displacement of a peripheral surface of the flange formed with the notch of the tool holder mounted on the main spindle; a storing device which stores basic eccentricity measurement data obtained by measuring the displacement of the peripheral surface of the flange of the tool holder mounted on the main spindle in a condition free from chuck errors and eccentricity measurement data obtained by measuring the displacement of the peripheral surface of the flange of the tool holder for chuck error detection; a calculating device which extracts a fundamental frequency component from the basic eccentricity measurement data and the eccentricity measurement data and makes a phase correction to at least one of the basic eccentricity measurement data and the eccentricity measurement data to obtain a true eccentricity from the amplitude value of the fundamental frequency component of the eccentricity measurement data for chuck error detection; and a judging device which judges an abnormality of the machine tool from the true eccentricity obtained.