| 摘要 |
PURPOSE:To improve operation efficiency, and to prevent false detection, by detecting vibration every chip, by comparing the vibration with the vibration of a chip at the previous stage and by detecting the vibration as abnormality when the difference becomes larger than a set point. CONSTITUTION:Vibration produced in the case when each chip 4b of a milling cutter 4 cuts a work is detected by means of a vibration detector 5 mounted to a main shaft head 1, and the output is input to a substraction circuit 8, a delay circuit 9 and wave-form shaping circuit 10 through an amplifier 7, etc. The output of a revolution detecting switch 11 working together with a dock 4c is input to a reference timing generator 12. Vibration detecting signals are delayed by means of the delay circuit 9 only by a portion corresponding to one pitch of the chips, and put out to the substraction circuit 8, and the signals and original signals are subtracted here and delivered to an integration circuit 14. The output of the integration circuit 14 is compared with a set point 16 by means of a comparison circuit 15, and an annunciator 19 is operated through a chip abnormality memory 17 in response to the output. |
