Methods On Thermal Analysis And Thermal Error Modeling In Working Space Of Horizontal Machine Tools

For high precision and super precision machine tools,the problem of thermal deformation of machine tools becomes more and more prominent.In the design phase of machine tools,it is important to rapidly analyse and evaluate thermal characteristics of machine tools and thermal errors in working space,so that designers of machine tools can complete inner heat resources layout design and structural optimization design oriented minimizing thermal deformation.In this thesis,horizontal machining center with box-in-box structure has be studied.Statical loads of horizontal machining center and thermal loads of linear feeding system were modelled.Thermal-structural coupling simulation for the horizontal machining center was completed,and thermal characteristics of horizontal machining center under thermal load,statical load and both of them were systematically studied.The thermal modelling method in working space of horizontal machining center was proposed,which is based on CAE thermal analysis results and multi-bodies theories.At last,the CAD/CAE thermal analysis module for horizontal machining center was developed.Taking the frame structure of horizontal machining center with box-in-box structure into account,statical loads of horizontal machining center were modelled,including spindle box-slide column,slide column – fixed column,working table – bed;and thermal loads of linear feeding system were modelled,according to the heat dissipation mechanism of feed system components.Simulation analysis of thermal-structural coupling of horizontal machining center with ANSYS is complished.The temperature field distribution in structures of horizontal machining center and the deformation field distribution because of thermal loads,statical loads,thermal loads and both of them were studied.Based on the deformation field of the thermal structure coupling simulation analysis of machining tools,the deformation curves of the guide rail were converted into 18 element thermal errors by the error theory.Then,the thermal error model in working space of the horizontal machining center was established based on multibody theories.CAD/CAE thermal analysis module for horizontal machining centers was developed,with Visual Studio and MATLAB as development tools,Creo Parametric and ANSYS as CAD/CAE platforms,Microsoft ACCESS as database.The results of this thesis are valuable for thermal balance design of horizontal machining centers,and they are useful for designers of machine tools to rapidly analyse and evaluate thermal characteristics of machine tools and thermal errors in working space in the design phase of machine tools.