Apparatus for detecting or predicting tool breakage

摘要

The apparatus has a cutting load detecting unit to obtain one of the cutting load data having a cutting time, an area of a cutting load waveform during cutting, and a maximum absolute value of a slope of a drop in the load during the cutting as a load state value in a current machining cycle. A unit updates and obtains a moving variable threshold based on the load state calculated in a machining cycle before the current cycle.