车间环境中遥测电火花加工状态的可能性

为了使多台电火花机床同时工作时遥测其加工状态成为可能,作者详尽地研究了加工时的电磁辐射频谱。通过实验证实:在近场内,电火花加工中的电磁辐射是有限带宽的白噪声,其“特证频率”是由于接收天线与测试仪器的阻抗失配引起的。而在远场内,所呈现的“特征频率”则是机床阻抗特性的反映,不同型号和尺寸的机床所辐射的信号频谱上就出现不同的“特征频率”。这样,能实现在车间环境中多台电加工机床同时工作时分别遥测它们的加工状态。

Possibility of Remote Monitor on Machining Conditions of EDM Machines

With the aim of remotely monitoring the machining conditions of several EDM machines operating simultaneously, frequency analyses of radiofrequeney radiation in sparking have been carefully made. It has been found that the frequency at which the most intensive signal is received corresponds to the fixed length of the receiving antenna if the latter is mounted near the machine. However, the radiation is almost at the same level at any frequency if it is received by an adjustable antenna and its length corresponds to the frequency at which the intensity is measured. In the far field, although a most intensive signal may be observed even if the length of the receiving antenna matches the sampling frequency, yet it appears at different frequencies with different types of machines. Moreover, there comes another intensive signal at a different frequency from that of the strongest one when an emitting antenna is connected to the machine. Various types and sizes of emitting antennae give off signals at different frequencies. Thus, it is possible to monitor remotely the machining conditions of several EDM machines operating simultaneously.