| 摘要 |
PURPOSE:To precisely detect an abnormality even if the margine of cutting is varied, by comparing a correlation value between power values of a main motor and a feed motor upon cutting, with a reference value which is a correlation between power values of the main and feed motors upon normal cutting. CONSTITUTION:The values of power for a main motor 1 and a feed motor 3 which are rotatingly controlled by a controller 5, are detected by a gate circuit 6. At first, upon cutting by a normal tool, a signal from the gate circuit 6 is transmitted through a gate circuit 7 to a correlation analyzing circuit 10 for setting a reference value. Then, upon usual cutting, a signal from the gate circuit 6 is computed in an arithmetic circuit 11 and is compared in a comparator circuit 12 for judging whether the cutting is abnoraml or not. |
