Tool diagnostic device

A tool diagnostic device for diagnosing a state of a tool used in an industrial machine for performing tapping, the tool diagnostic device comprising:

• a data acquisition unit configured to acquire, as waveform data, a state quantity of a motor for driving the tool before and after rotation of the tool stops in the tapping;
• a reference waveform generation unit configured to generate reference waveform data based on waveform data acquired during first machining by the tool;
• a difference waveform calculation unit configured to calculate, as difference waveform data, a difference between waveform data acquired by the data acquisition unit and the reference waveform data;
• a waveform feature calculation unit configured to calculate waveform feature data indicating a feature of a waveform from the difference waveform data;
• a learning result storage unit configured to store a learning result of learning a correlation between waveform feature data and a time for next tool replacement;
• and
• a state diagnostic unit configured to diagnose a state of the tool based on the waveform feature data using a learning result stored in the learning result storage unit,
• wherein the waveform feature calculation unit calculates waveform feature data from data in a section of at least one of a deceleration part before rotation of the motor stops and an acceleration part after rotation of the motor stops in the difference waveform data.