Structural Optimization Design Of Integral Piezoelectric Milling Force-measuring Platform

Being the most basic instrument and means of the study of grinding process and test, piezoelectric grinding dynamometer can recognize fault quickly, close off its root, and improve reliability and manufacturing efficiency of cutting process. It is also the most important part of realizing state monitoring, adaptive control and optimization control during the course of modern automatic cutting process. Accordingly it is very significant to develop a grinding dynamometer with excellent performance.This paper continues the science research named developing the piezoelectric turning dynamometer which is proposed by NO. 78-264 document from the National Plan Committee. It is also the new issue supported by the National Natural Science Fund (6864025) (59175233) at the same time.The mutual matching of rigidity from three directions between elastic ring and sensor is the core of problem of structural optimization design of unitary piezoelectric grinding force-measuring platform. From the core of optimization design, this paper analysed and calculated the key dimensions of the structure of force sensor from three directions with equal stiffness on the basis of force analysis, and then optimized boundary conditions of the structure of elastic ring are worked out exactly. At the same time, a three-dimension solids parameterized model of force-measuring platform is established by using the finite element method. Then using the finite element optimization module for ANAYS completed the structural optimization design of the force-measuring platform and acquired the optimal structure parameters. By the static calibration, the dynamic calibration and cutting experiments, it is proved that the force-measuring platform has fully reached the dynamic dynamometer standard stipulated by CIRP-STCC and provided reference and direction of theory for design, manufacturing and research of grinding dynamometer.The outstanding advantages of the optimized force-measuring platform compared with the original one are as follows: equal stiffness design is realized and Y direction stiffness is improved by 39 percent. The maximum equal stress reduced by 16.16 percent. Sensitivity of sensor is higher, especially main cutting force can reach to 5.42pC/N. The calibration results show that the linearity and repeat degrees are both less than 0.2% and the natural frequency has been improved from 3.51kHz to 6.2 kHz. The optimization result is prominent and correlative dimensions are much more reasonable. So it is used not only in the laboratory butalso in testing of practical and real-time control.