The Research And Design On Three-Component Piezoelectric Drilling Dynamometer And Torque-Loading Device

The drilling dynamometer is a fundamental device of researching the drilling process. By the change of drilling force in the process, people can detect a malfunction. So it is a necessary part of real-time monitoring, self-adapting, optimum control in the automatous machining process. With the development of technology, the functions and performances of the drilling dynamometer are under improvement.This project is funded by the National Natural Science Foundation of China (No. 50475152). From the application aspect of engineering, interdisciplinary knowledge, such as Physics of Crystals, Physics of Dielectrics, Piezoelectricity, Theory of Elasticity of an Anisotropic Body, Electromagnetics is utilized in the investigation on design and manufacture of the drilling dynamometer. On the basis of theory analysis, the key dimensions and dynamic characteristic of the drilling dynamometer are designed and analyzed according to its specialty and applied demand. Based on the torsion effect of the piezoelectric quartz slice, the three-component piezoelectric drilling dynamometer can measure a torque. It can also measure an axial force and a radial force though it is composed of only four slices of quartz. The measuring range is M_z =0 ~ 9 N.m , F_z =0 ~ 1500N, F_x =0 ~ 1000N. By the staticcalibration, the dynamic calibration and practical application, it is showed that the performances of the three-component piezoelectric drilling dynamometer are up to need. The outstanding feature of the three-component piezoelectric dynamometer in contrary to other types of drilling dynamometers is as follows: it adopts torsion effect of square quartz with a circular hole inside, which makes no-centering measuring of drilling process come true. Only two slices of Y0°-cut quartz are used in a torque and a radial force measuring. The structure is simple and convenient for checkout. The technical performances of machining and assembling are good, and its production cost is low. The dynamometer can measure three components forces at the same time; therefore, the distributing situation about cutting forces in drilling process is described more completely.A torque-loading device is designed and manufactured, which can load a pure torsion. Flexible hinges form guidance. Given a force, the torque-loading device can produce an equilibrated and symmetrical torsion. It gains advantages of simple structure and easy manufacture. Dimension parameters and location parameters of the flexible hinges are the key...