| Nowadays,CNC machine tools are developing towards high precision and flexibility,and the requirements for reliability and processing accuracy of machine tools are getting higher and higher.Under the combined action of external environment temperature and internal heat source,a great deal of heat will be generated during the whole operation period of the machine tool.These heat will be transferred by heat conduction and heat convection between the parts of the numerical control machine tool,which will generate non-uniform temperature field between the parts of the machine tool.Thus,the parts of the machine tool will be transformed into non-uniform temperature field.Forming different degrees of thermal deformation.In the process of researching how to reduce the machining errors of machine tools,we know that the thermal errors of machine tools account for a large proportion of the total machining errors of machine tools.As the core component of CNC lathe,the thermal characteristics of spindle under the action of heat source have a particularly serious impact on the accuracy of machine tool processing.Therefore,it is very important to analyze the temperature field and thermal deformation of spindle unit to reduce the machining error of machine toolTaking the spindle of ETC3650 NC lathe as the research object,the finite element software is used as the analysis tool.By analyzing the heat source,calculating the calorific value and numerical simulation,the steady temperature distribution of the spindle and the thermal deformation of the spindle in X,Y and Z directions are obtained The temperature rise of the spindle box and the thermal deformation of the spindle are also studied.The validity of the finite element analysis is verified by the test data.The following is the specific research content of the paper1.By consulting the relevant literature at home and abroad,the current situation and development of thermal characteristic analysis of machine tool spindle components are mastered.The main contents and practical significance of the research are described,and the ideas and methods of the research are determined2.The three-dimensional temperature field mathematical model of machine tool spindle components is established.Based on the basic equation of thermal deformation,elasticity and finite element theory,the mathematical model of thermal deformation is established3.The three-dimensional CAD model of machine tool spindle system is established,the finite element meshing and the heat conduction coefficient of the joint surface are discussed,and the finite element model of thermal characteristics is established,which lays a foundation for the analysis of thermal characteristics.4.The internal heat source and boundary conditions of the spindle system of the machine tool are analyzed,and the finite element model of the temperature field of the spindle system is established.The temperature field of machine tool spindle system is simulated and analyzed by using analysis software and finite element method,and the temperature field distribution figure of spindle structure is obtained.The temperature field model of the spindle system of ETC3650 NC lathe is verified by experiment,and the temperature field is analyzed.The spindle temperature rise experiment and ANSYS analysis of the spindle temperature field distribution are established through the spindle test system.The temperature distribution of the spindle is compared and analyzed,and the correctness of the finite element model is analyzed.It laid a foundation for further calculation of thermal deformation and thermal characteristics analysis.5.The constraints and thermal loads are determined,the steady-state temperature field of the spindle is analyzed,and the thermal deformation caused by the spindle running is analyzed,and the effect of thermal deformation on the structure of the spindle is studied.The displacement sensor is used to establish the spindle thermal displacement experiment.The simulation results and the correctness of the finite element model are given.The thermal deformation of machine tool spindle system is analyzed in detail,and the degree of influence of thermal deformation of machine tool spindle system on machine tool processing accuracy is determined6.The reasons for errors between simulation analysis and measured values are explored.On the basis of theoretical analysis and experimental verification,the improvement measures for thermal characteristics of lathe spindle are put forward.The specific contents of various improvement measures are discussed in detail.The following optimum design of spindle and the development of high precision lathe are realized to a certain extent real meaning.Based on the above contents,this paper studies the thermal characteristics of CNC lathe spindle,obtains the results of its thermal characteristics analysis,and puts forward the improvement scheme of the thermal characteristics of CNC lathe spindle,which is conducive to the development of lathe spindle in the direction of high power,high reliability and high precision. |
PDF Full Text Request