| 摘要 |
PURPOSE:To reduce the measurement error of a cutting load by measuring the load current value every half a rotation of a main shaft so that the measured data of this time and the previous time are averaged to obtain the cutting load. CONSTITUTION:When dogs adhered to the periphery of a main shaft at a 180 deg. pitch is sensed by a sensor, the load current value Im of the main shaft is measured. A previously measured value Imt and a presently measured value Imt are averaged as a cutting load value Imm, and if it exceeds the preset upper limit value, the feeding speed is reduced and controlled so that the load does not exceed a constant value. The load current Im is like a sinusoidal wave coinciding with the rotating period T1 of the main shaft, therefore, by measuring it every half a rotating period of the main shaft, the correct measurement of the cutting load and a precise feed control can be implemented even if the rotating speed of the main shaft and measuring time are varied. |
