Researches On The Monitoring Of Milling Tool Fracture For The Machining Center

As an important component of FMS,IMS techniques in manufacturing automation,the on-line monitoring of cutting tool failure during the cutting process plays a significant role in improving the productivity, bettering the machining quality, reducing the production cost and assuring high efficiency and reliability of the automatic processing system.In this dissertation, the development and current situation of the methods of monitoring the tool failure during the machining process are reviewed in detail, followed by a summary of the classification of the adaptive control technology during the machining process are also described . A method of real - time monitoring milling cutter failure is presented. The method samples the signals of spindle vibration displacement and the spindle electrical machinery power signal using the synchronized sampling technique. As the two kinds of signals are all non - contact pick - ups,this method is very suitable for the machining centre. An analysis of the vibration displacement signal shows that when the spindle runs at medium and low speeds, the viration displacement signal well reproduces the milling force signal.This dissertation makes an in - depth analysis of the power signal and the principles of power monitoring . It establishes the mathematicl model of the energy transmitting in the machinery and power system of the machine tool. Based on this model, the performance of the spindle electrical machiner-y power signal reproducing the cutting power signal is analyzed . Then the de-lay differential method of detecting the milling cutter breakage is put forwardAccording to the above research work and the changing characteristics of power signal and vibration displacement signal when the tool breakage occurs, the monitoring stategy of sensors fusion based on the artificial neural network is put forward . The monitoring system of milling cutter breakage based on the information fusion of the power signal and vibration displace-ment signal has been developed. The diff culty in giving a dectecting threshold due to the changeable character of character of cutting condition has been solved , and a good reliability is ensured over a wide range of conditions .