Design And Experimental Study Of Vibration-Measuring Tool Handle For Milling

With the development of modern cutting technology towards high efficiency and high precision,higher requirements are put forward for cutting precision,surface quality and machining efficiency.The relative vibration of cutting tool and workpiece not only reduces the surface quality of workpiece,but also aggravates tool wear,which affects machining precision and production cost.In order to reduce the influence of tool wear on the workpiece surface quality and machining accuracy in the process of machining,effectively utilize the tool cutting life,reduce the production cost and improve the machining efficiency,it is of great significance to collect the cutting vibration information of machining and monitor the tool wear state.In the cutting vibration monitoring of milling,the traditional method is to stick the acceleration sensor on the workpiece or spindle to collect the vibration signal.This monitoring method has poor repeatability and cannot effectively eliminate the influence of position deviation.And because the sensor is too far away from the cutting area,the vibration signal detected is very weak,so it is difficult to meet the need of vibration signal online monitoring.In this paper,the design and application of milling vibration detection tool holder with acceleration sensor and data acquisition circuit is studied.The specific research content is as follows:(1)In this paper,the vibration detection tool handle scheme of integrated sensor is designed in general,including the selection of sensor and the design of tool handle system structure for dynamic balance and stiffness problems.The stiffness,natural frequency and vibration signal of tool handle structure are analyzed and verified by finite element simulation method.(2)The software and hardware of the vibration signal acquisition system and the wireless transmission system are designed.The wireless transmission of the vibration signal is realized through wi-fi.The upper computer software interface is written by using the mixed programming of Qt and MATLAB.(3)Dynamic balance adjustment is carried out on the developed vibration detection tool handle.An experimental platform for vibration detection tool shank system is built on a three-axis CNC milling machine.The idling and milling experiments were carried out by using the wireless vibration detection tool holder system,the influence of spindle idling on vibration signal acquisition was analyzed,the vibration measurement performance of the tool holder was compared with the traditional vibration measurement method,and the influence of cutting parameters on vibration signal was studied,and the vibration monitoring performance of the tool holder used in milling was verified.(4)the vibration signal processing method is studied,and the tool wear state identification model is constructed.Based on the vibration signal data obtained from the vibration detection tool holder in the milling experiment,the signal noise reduction method is analyzed,and the signal features in timefrequency domain,signal fractal features and wavelet packet frequency band energy distribution characteristics are extracted.Taking the above signal characteristics and spindle speed as input nodes and four tool wear states as output nodes,the neural network was trained to obtain a tool wear state identification model,which was verified by tool wear experiments.