Characteristic Analysis And Thermal Deformation Experimental Research Of The A/B Biaxial Rotary Milling Head

The biaxial rotary milling head is the core functional component of five-axis CNC machine tool.What makes it a hotspot and difficulty in machine tool industry is its high precision,high stability and high stiffness.The performance of biaxial rotary milling head directly affects the machining accuracy of machine tools.And many machine tool manufacturers invested a large number of energy and financial resources to work on it.How to improve the accuracy of biaxial rotary milling head has become a widespread problem,which plenty of researchers are eager to solve.Among all factors affecting milling head accuracy,the thermal errors account for a large proportion.Therefore,it is significent to research regularities of thermal deformation of biaxial rotary milling head for improving the performances of the milling head.In this paper,the research object is a biaxial rotary milling head that an enterprise researched and developed independently.The A/B biaxial rotary milling head was researched in characteristic simulation analysis and thermal experiment with the methor of combining the finite element simulation and experiments.The purpose is to verify the validity of the milling head structure and provide theoretical basis for the enterprise to optimize and improve.Firstly,introduced the basic situation of the biaxial rotary milling head used in this papert briefly,including its characteristics,performance,structure and technical parameters,and introduced the key parts of the milling head in detail.On this basis,analyzed the sources of thermal error of the milling head and heat source parts one by one.And calculated the corresponding heat generated differently.Basing on the heat transfer theory,analyzed several typical heat exchange forms in biaxial rotary milling head.And calculated the specific coefficient of heat transfer of the milling head according to the empirical formula.Secondly,established and simplified the three-dimensional model of the biaxial rotary milling head with the three-dimensional modeling software to make meshing and calculation more convenient.Carried out static analysis by ANSYS Workbench software.Got the results of stress and strain of the milling head under the only gravity and combined gravity and cutting force.At the same time,Carried out modal analysis and got the first six natural frequencies and mode shapes.Pointed out.the reasons of lower frequency of milling head.After that,carried out the thermal stability analysis.Obtained the temperature and deformation of the final state of the milling head.Then,the thermal transient analysis is carried out to obtain the temperature and deformation variation law of the milling head at different times,and drawn the curves of the temperature and displacement of the milling head versus time.Finally,in order to verify the correctness of the finite element analysis,carried on the thermal deformation experiment of the biaxial rotary milling head.Collected the temperature data and data of displacement of the tool tip of the milling head,and compared with the simulation results.The errors of emperature and displacement are all within the allowable range,which proved the correctness of the simulation analysis.At the same time,the data obtained of displacement-time relationship can be used in thermal error compensation.