| Thin-walled integral impeller parts with complex characteristic surfaces are widely used in aviation,Marine power and other fields.Flank milling processing method can make full use of the flexibility of multi-axis CNC machine tools,and the processing efficiency is higher.Main error of flank milling comes from the principle and practical in the process of thin blade deformation in the process of machining,the size and distribution of lateral milling principle error condition is mainly composed of the complexity of the thin blade curved surface and the algorithm of optimization,the deformation of machining is mainly caused by the machining parameters and especially the milling force.In order to reduce and suppress the error of thin-walled blade and obtain the tool path with the minimum comprehensive error,this paper obtains the tool path with the minimum error by means of process optimization and error compensation.In the process of flank milling,the milling force and the blade deformation at each cutter position are different due to the different geometric parameters of the blade.For achieving accurate error suppression and compensation and obtaining the minimum error of the cutter position,the deformation at each cutter position of the blade needs to be analyzed.Therefore,this paper begin with analyzing the blade’s geometric parameters,calculates the blade’s milling force with the method of micro-element milling force calculation,and obtains the blade’s cutter position elastic deformation error model by using the finite element analysis method.Firstly,from the point of view of process optimization,a continuous side milling non-uniform allowance optimization method was proposed before finishing to suppress the side milling deformation error of thin-walled blades.According to blade geometry information,the stiffness measurement index was put forward.Through the relationship between the stiffness index and blade elastic deformation error model,the function relationship between the stiffness index and the finishing allowance was established.The regression equation of finishing allowance on blade geometry parameters was obtained by using regression analysis method,according to the regression equation and tool path optimization,the continuous non-uniform allowance is reserved before finishing.The optimized non-uniform allowance reserved tool position can effectively suppress the elastic deformation of the blade in the final finishing process.Secondly,the milling tool is simplified as a piecewise cantilever beam model,and the error of tool deformation in the machining process of the blade is obtained by applying the milling force on the cutting contact area.After the blade and tool deformation error models were obtained,respectively,the blade and tool deformation error models were introduced into the tool path optimization algorithm for flank milling.By expressing the algorithm error,a new tool location planning method based on flank milling deformation error compensation was proposed.Finally,in view of the generated error compensation tool proposed error compensation tool quality comprehensive error evaluation method,the new method of the error predictive compensation planning tool and the traditional method of planning compensation evaluation,comprehensive error evaluation showed that this method is used for straight grain surface and class ruled surface thin blade flank milling,compared with traditional knife-deformation compensation strategy,the comprehensive error of the generated tool position is the smallest,and the error calculated by this method is more accurate and effective,which can improve the efficiency and reliability of the tool position planning in flank milling. |
