Patent ID: 11913992
Assignee: MAZIN INC.
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 5:
6. A current measuring method for a machine tool which comprises a first motor that receives load fluctuation when a workpiece is processed, and a second motor that operates to change a tool to a different kind of tool and which processes the workpiece while changing plural kinds of tools, the current measuring method comprising:
causing an information processing device to which a first current sensor and a second current sensor are connected to perform a process of overlapping a time-history waveform of a current which flows through the first motor and which is measured by the first current sensor with a time-history waveform of a current which flows through the second motor and which is measured by the second current sensor in such a way that respective elapsed times match with each other;
causing the information processing device to perform a process of identifying a changing operation of the plural kinds of tools from the current which flows through the second motor and which is measured by the second current sensor to determine a segment where each of the plural kinds of tools is used; and
causing the information processing device to perform a process of taking out the current of the first motor measured by the first current sensor for the segment where each of the plural kinds of tools is used, and relatively comparing a non-negative function value that has a current value at each taken-out segment as a parameter for each number of times of processing on the workpiece, thereby detecting a tool abnormality for each kind of the tool.