Method for judging key moments in whole process of machining step for computer numerical control machine tools

A method for judging key moments in a whole process of a machining step for computer numerical control machine tools, wherein, before judgment, an input power range PUmin˜PUmax of a spindle of the computer numerical control machine tools in an idling process state is acquired and stored, and during judgment process, following steps are comprised:

• when a workpiece is machined, reading an execution state, of a numerical control code of the computer numerical control machine tools in real time, acquiring and recording an execution starting moment tU1s of a cutting feeding code, and then judging the execution starting moment tU1s as a feeding starting moment tU1s in the machining step as well as a starting moment tU1s of a first idling state;
• after a first idling process in the machining step is started, acquiring a real-time input power Pi of the spindle of the computer numerical control machine tools, and when the input power Pi increases and exceeds maximum input power PUmax of the spindle in an idling process state, recording an increasing moment, and then judging the increasing moment as a starting moment tCs of a cutting state in the machining step as well as an ending moment of the first idling process state;
• after the cutting state in the machining step is started and when the input power Pi decreases to be lower than PUmax and is kept within the input power range PUmin˜PUmax of the spindle in the idling process state, recording a decreasing moment and then judging the decreasing moment as an ending moment tCe of the cutting state in the machining step as well as a starting moment of a second idling state;
• and
• after the cutting state in the machining step is ended, reading the execution state of the numerical control code of the computer numerical control machine tools in real time, acquiring and recording an execution ending moment of the cutting feeding code, and judging the execution ending moment as a feeding ending moment tU2e in the machining step as well as an ending moment tU2e of the second idling process state.