Development Of Piezoelectric Three-component Force Unit With Self-preloaded

In the process of using the method of mirror milling to manufacture thin plate of large rockets, the magnitude and direction of support force not only has a decisive influence to the production quality and efficiency of the plate, but also is an important indicator which shows the real state of milling force. The size and the tendency of online monitoring of the supporting force, combined with the processing requirements of the thin plate, can adjust the process parameters such as milling cutter speed and the feed rate timely. In order to keep the large diameter plate has always maintained a high degree of stability and efficiency in the thinning of the milling process.According to the demand of real-time measurement of the mirror supporting force of milling method, combined with the structure of self adaptive mechanism in the self searching machining of large thin plate, based on the piezoelectric effect as the theoretical basis, developed a piezoelectric three-dimensional support force measurement unit for limit space. The force measuring unit is arranged in the middle of a three force sensor as force electricity conversion component, to realize the simultaneous measurement of three orthogonal directions supporting force in the milling process of large thin plate.According to the measurement conditions of the supporting force space limited,reference range and sensitivity of the force unit. Design the structure of sensor and the upper and lower pressing block. Discuss the project of perload of the force unit, calculates the preload and the diameter of the perload,check the tangential range. Static analysis by using ANSYS software on the sensor crystal group and crystal shell, selection of the force unit with parameters of high stiffness, static analysis and modal analysis of the force measuring unit, testify good linearity and high natural frequency.Under laboratory conditions, process the static calibration of force measuring unit. The results show that the force measuring unit has a good static characteristics. Establish dynamic calibration dynamometer experimental device, the dynamic properties of dynamometer are analyzed by using ball impact method, verify the force measuring unit has a high natural frequency. The technical indicators of the measuring unit meet the technical index, namely the force measuring unit can meet the dynamic supporting force, it provides reliable guarantee for the stability of large thin plate in the mirror milling process.