Machine tool and information processing device

An information processing device provided in a machine tool comprising:

• a movable body that supports a cutting tool configured to perform a machining operation;
• a servomotor that feed-drives the movable body;
• and
• an acceleration sensor that detects acceleration of the movable body,
• a vibration diagnostic amplifier amplifying an electric current signal detected by the acceleration sensor,
• the information processing device comprising:
• a processor,
• wherein the processor includes:
• a numerical control unit that controls the feed drive by the servomotor to perform cutting by the cutting tool;
• a state monitoring unit that monitors a control state of the numerical control unit;
• a stop command unit that outputs a stop command to stop driving of a servomotor to the numerical control unit when an acceleration of the movable body exceeds a threshold value set in advance on a basis of an output of the vibration diagnostic amplifier;
• and
• a threshold value setting unit that changes a setting of the threshold value according to the control state,
• wherein the acceleration of the movable body is calculated on the basis of composite vector of accelerations detected in multiple directions,
• wherein the threshold value setting unit sets a first threshold value as the threshold value in a cutting control state, and sets a second threshold value lower than the first threshold value as the threshold value in a feed control in a non-cutting control state,
• wherein the vibration diagnostic amplifier stores the threshold values, and
• wherein a vibration detection is further performed in which vibration during cutting feed is monitored on the basis of the output the acceleration sensor, and the command unit outputs a stop command for stopping the driving of the servomotor to the numerical control unit when the vibration of the movable body continues for at least a predetermined period of time during the cutting feed even in a range not exceeding the first threshold value set by the command unit.