Research And Development Of Vibration Testing And Modal Analysis System For CNC Machine Tools

The CNC machine tools is a typical integrated products,which has been widely used in aviation,aerospace,shipbuilding,weapons,cars,molds and medical equipment and other industries.It is the foundation of equipment manufacturing.Machine parts of the CNC machine tools are subjected to high temperature,wear,impact,corrosion and so on for a long time,which accelerates the wear of machine parts and reduce the life of the machine tool.Then unexpected failure will occur.Vibration testing and modal analysis are the effective methods to solve the faults.The structure parameters and modal parameters will change when the mechanical structure break down.So the modal parameters can be used as a method to determine the early failure of CNC machine tools.Therefore,developing the vibration testing and modal analysis system for CNC machine tools has important practical significance and engineering application value.The article relies on the National Key Scientific Apparatus Development of Special Item.In view of the main vibration problems of NC machine tools,the following work is mainly done.(1)This article summarizes the research on vibration testing and modal analysis at home and abroad.The structural characteristics of NC machine tools are analyzed,and the main vibration parts and vibration problems are summarized.The common vibration test requirements of CNC machine tools are analyzed in detail.Then the hardware needed for acquisition and measurement is set up.A complete set of NC machine tool vibration testing and modal analysis system is completed.(2)Based on the software of LabVIEW,a set of guide type of vibration testing and modal analysis system is developed,in view of the vibration of numerical control machine signal mechanism and features,combined with the technology of fault diagnosis and modal analysis.The system can achieve 8 channel high speed data acquisition,data analysis,data storage,data playback and modal analysis and so on.Design process and the key part of the design thought of the software are detailed introduced,and the part of front panel design is given.(3)At last,the system is used to test a small machine tools produced by a company.The vibration signals of the CNC machine tools are acquired,and the modal analysis of them are also carried out.And the results were compared with the PLISE software testing.Practices prove that various functions of the software satisfy the requirements of condition vibration testing and modal analysis and verify that the software system is reliable and useful.