ABNORMALITY DIAGNOSIS DEVICE FOR MACHINE TOOL, AND ABNORMALITY DIAGNOSIS METHOD

摘要

Provided is an abnormality diagnosis device for a machine tool, and an abnormality diagnosis method, whereby it is possible to diagnose the degree of damage to a spindle system due to a collision. An abnormality diagnosis device (40) for a machine tool (1) has: a displacement sensor (36) for detecting the amount of displacement of a spindle bearing (30); an acceleration sensor (38) for detecting the acceleration of a ram (28); a collision determination unit (46) for determining whether the ram or a spindle (32) has collided with a work piece, on the basis of at least the amount of displacement of the spindle bearing detected by the displacement sensor or the acceleration of the ram detected by the acceleration sensor; and a damage determination unit (50) for determining the degree of damage to the spindle bearing on the basis of at least the amount of displacement of the spindle bearing, the acceleration of the ram, or a frequency characteristic of vibration of the ram due to rotation of the spindle obtained from the acceleration of the ram, when the collision determination unit determines that the ram or the spindle has collided with the work piece.