| 摘要 |
PURPOSE:To detect an abnormality of a tool while avoiding erroneously detecting an abnormality caused by external noise, by providing an AE sensor on and opening in each of plate members through which AE waves may be transmitted, and by attaching these plate members to a machine body at plural positions which are located at predetermined intervals along the longitudinal direction of a spindle. CONSTITUTION:When AE waves are generated due to an abnormality of a tool, these are transmitted directly to a spindle, and are then transmitted to plate members 10 through openings so that these are detected by AE sensors 9a, 9b. Since the AE waves are transmitted through the spindle, the AE sensors detect them with a time lapse therebetween, corresponding to intervals of the attached sensors, and therefore, a control circuit 19 issues an abnormality sensing output only when the above-mentioned time lapse is detected. Accordingly, even if AE waves caused by external noise are detected, no abnormality sensing output is issued, and thereby it is possible to accurately detect an abnormality of a cutting tool. |
