Development Of Piezoelectric Cutting Force Self-sensing Tool

As the "teeth" of machine tools in the process of mechanical processing,the state of the cutter can be reflected not only by the surface quality of the machined parts,but also by the change of cutting force.Cutting force is an important indicator of tool condition monitoring.According to the cutting condition reflected by the change of cutting force,cutting parameters can be adjusted in time to improve cutting efficiency and prolong tool life.Therefore,the monitoring of cutting force in cutting process is of great significance to intelligent manufacturing.With the rapid development of micro-sensing technology,the application of integration idea to insert sensing elements into cutting tools for realtime monitoring cutting force can not only reduce the inconvenience caused by external dynamometer,but also reduce the cost of monitoringIn this paper,a tool configuration for inserting piezoelectric ceramic sheets into the tool pad to sense cutting force is proposed.Firstly,the shape and size of piezoelectric ceramic sheets are determined through the structural design of the sensing transducer.Then,modal analysis and piezoelectric coupling analysis are carried out for the developed tool.Finally,the performance indexes are determined through experiments,which shows that the design is feasible.The main contents of this paper are as follows:(1)Firstly,according to the piezoelectric effect of piezoelectric ceramics,the structure of sensing transducer is designed;the type of piezoelectric ceramics is PZT-5H,and the piezoelectric ceramics is circular by stress analysis;the size of piezoelectric ceramics is 12 mm,5 mm and 2 mm by theoretical calculation;then,the vibration between Z-direction cutting force and load is established by lumped mass method.The mechanical model and the preparation of sensing transducer are completed.(2)The modal analysis and piezoelectric coupling analysis of the threedimensional simplified model of piezoelectric cutting force self-sensing tool are carried out by ANSYS.The natural frequency of the sensing tool is 1724.2HZ by modal analysis,and the changes of vibration modes are analyzed to verify that the designed tool will not be damaged by resonance.The voltage response under different loads is obtained by piezoelectric coupling analysis,and the load response analysis is carried out.The results show that there is a good linear relationship between load and voltage,and the linearity error is 0.25%.(3)The static and dynamic performance index of the perceptual tool is calibrated by step-by-step addition or step-by-step subtraction and impulse response.The results show that the designed piezoelectric cutting force selfsensing tool has good static performance and high natural frequency.The actual cutting test of piezoelectric cutting force self-sensing tool is carried out by orthogonal test of three factors and three levels,and the obtained voltage value is converted into cutting force calculated by classical empirical formula.The results show that the measuring rotation is achieved when the cutting force is less than 300 N.The conversion value has a good linear relationship with the empirical calculation value,and the linearity error is 0.37%.