Abstract:
A measured data pass-fail discriminating apparatus comprising a digital display type measuring instrument (1) and a data discriminating device (2) for discriminating pass or fail of measured data inputted from the measuring instrument (2). In the data discriminating device (2), the upper limit value (HH) and the lower limit value (LL) are set, and the upper limit preview value (H) and the lower limit preview value (L) are set closer to reference values than the upper limit value (HH) and lower limit value (LL). An alarm signal is given when the measured data having the same number as the preset judging frequency (Jl) continuously lies in ranges between the upper limit preview value (H) and the upper limit value (HH) and between the lower preview value (L) and the lower limit value (LL), or when the measured data exceed the upper limit value (H) and the lower limit value (L).
Abstract:
A method of monitoring machining load on a numerically controlled machine tool in such a way that incorrect judgment due to variations in machining load which are caused according to the machining conditions is made less frequent. The method is started by performing plural trial cutting operations. A signal indicating the machining load during these trial cutting operations is sampled and thus, sampling data is obtained. Reference data about the machining load and its variance are calculated from the sampling data and loaded in a reference data table. A threshold value according to variations in the sampling data is established, using the value of the variance. A load monitor means compares the reference data with data about the machining load obtained from actual measurements whenever each interval of time elapses. A decision is made as to whether the difference exceeds the threshold value. In this way, the machining load is monitored.