Research On Machining Deformation Of Casing Based On Auxiliary Support

In recent years,with the continuous improvement of aero engines performance,the casing parts is required to have good performance,the casing parts at the beginning of design put forward strict requirements for dimensional accuracy and geometric tolerance,which brought great difficulties to machining.In this paper,the process of milling the outer surface of machine casing is taken as the background,The machining error is studied,and the machining error is improved by adding auxiliary support.In the past,the average milling force calculated by empirical formula was used as the milling force load,while the milling force load in the cutting area was instantaneous milling force.To solve this problem,a dynamic milling force model which can reflect the instantaneous milling force of R milling cutter for high temperature alloy is established.The correctness of the model is verified by milling force measurement experiment,and the subsequent milling error analysis is carried out based on the milling force calculated by the model.In view of the existing defects in the analysis of the machining error of thin-walled parts by the present finite element technique,this research used the two development of the finite element software ABAQUS,use the Python scripting language for the two development of the ABAQUS preprocessing module,the milling force is loaded one by one to the nodes in the cutting area,and the elastic deformation of each point under the action of the milling force is calculated as the machining error of the point.The above two methods are applied to study the machining error of the outer surface of the casing without auxiliary support,which can accurately and comprehensively predict the error of the machining area.The axial position of the auxiliary supporting unit of the auxiliary supporting fixture is optimized.The influence of the supporting area size and the supporting force on the external surface machining error is studied.In view of the defects of the auxiliary supporting fixture used at present,the new supporting fixture is obtained.The number of auxiliary supporting units and the layout of auxiliary supporting units are optimized.Finally,the layout of auxiliary supporting units with the smallest amount of external surface machining is obtained.