Development Of Reliability Test System For NC Lathe Based On Piezoelectric Ceramic Loading

CNC machine tools represent the comprehensive level of the country's manufacturing industry.Our country has been the world's largest machine tool manufacturer and consumer for many years.However,more than 85% of the mid-to-highend market has been occupied by brands from developed countries.The main reason is the frequent failures and poor reliability of domestic CNC machine tools.Reliability has become a bottleneck restricting the development of domestic CNC machine tools.Reliability test is the basic work of product reliability engineering research.It is not only the main means of evaluating product reliability,but also the key way to obtain product reliability data.At present,the acquisition of reliability data of CNC machine tools mainly relies on on-site tracking tests and reliability bench tests.On-site tracking tests of machine tool user enterprises have shortcomings such as long periods and uncontrollable conditions.The reliability laboratory bench test can quickly stimulate product failures in the laboratory by simulating the actual working conditions of the product,with a short test period and controllable test conditions.In this paper,under the support of the national science and technology major subproject,"Reliability Growth Engineering Research of Key Functional Components of CNC Machine Tools",aiming at the problems of low loading frequency and poor portability of the reliability test bench of CNC lathes,piezoelectric ceramics are used as loading device,a portable reliability test system for CNC lathes with working condition simulation capability is developed.The main research work is as follows:(1)Firstly,the composition and typical load characteristics of CNC lathe are analyzed,and the functional requirements are determined;The overall scheme of this test system of CNC lathe based on piezoelectric ceramic loading is designed.(2)Design and optimize the mechanical part of the reliability test system.Firstly,Solid Works software is used to establish the 3D model of the mechanical part of the test system,and then the parameters of the radial fixture and axial fixture of the test system are set,and the strength and stiffness of the test system are simulated and analyzed by ANSYS.(3)Development the control system.Firstly,the control scheme is designed,and the transfer function is obtained by establishing the model,and the parameters of the transfer function identified by using MATLAB.Secondly,combined with the system transfer function,PID and fuzzy PID controllers are designed,and the simulation method is used to compare and analyze them.(4)Develop the software platform and conduct the simulation accuracy test.Based on Lab VIEW,the platform of the reliability test system is built,and the functions of test parameter setting,data status display and data acquisition are realized.On this basis,the load simulation test is conducted.The reliability test system of CNC lathe was verified.