Research On Optimization Method Of Tool Paths And Process Parameters And Experiments For Five-Axis Nc Milling Centrifugal Impeller

As the strategic industry of a country， the level of manufacturing process foraero-engine reflected the technical strength in developing sophisticated equipment for acountry. The centrifugal impeller as one of key parts of aero-engine, its machining accuracyaffects the properties of aero-engine directly, such as aerodynamics and mechanical efficiency.At present, although the multi-axis NC milling manufacturing process of centrifugal impellerblades in our country has made a great progress, it is rather backward from foreign. And thereasons can be summarized as follows: the complex geometry of centrifugal impeller, belongto the thin-walled structure, poor overall rigidity. As a result, there are many problemsincluding the geometric programming error, the cutting deflection error and difficulty tochoose appropriate process parameters in the process of five-axis NC milling. How toestablish appropriate tool paths optimization algorithms and process parameters optimizationtheory is an important project for achieving the high-efficiency and high-quality processing ofcentrifugal impeller blades. Therefore, it is urgent to conduct the researches on cutter-locationand process parameter optimization for improving the machining accuracy and efficiency ofcentrifugal impeller blades. So, the multi-axis NC milling theory, cutter-location optimizationprinciple, cutting deflection error compensation theory, numerical simulation and databasedevelopment technology, cutting experiment are adopted to explore the theory of tool pathsand process parameters optimization for centrifugal impeller blades multi-axis NC milling.Specific studies are as follows:1) A double parameter cutter-location optimization algorithm is established to induce thegeometric programming error, which based on the disadvantages of the existing algorithms,NC flank milling theory and geometry structure of centrifugal impeller. The cutter-locationcalculating and post processing software is developed in UG-GRIP and VC++languages. Andan example calculation for analysis and contrast of the geometric programming error betweenthe existing algorithms is accomplished by numerical simulation calculation and VERICUT.2) The influence law of milling force resulting from the process parameters in theprocess of centrifugal impeller blades five-axis NC milling is found by orthogonal test andvariance analysis. And the milling force model is also established based on regressionequation.3) The influence law of cutting deflection error of centrifugal impeller blades five-axisNC milling is found with finite element analysis software ANSYS. And a tool pathsoptimization algorithm for centrifugal impeller blades five-axis NC flank milling is proposed by cutting deflection error compensation and tool paths optimization theory.4) A process parameters mathematical optimization model for centrifugal impeller bladesfive-axis NC milling is established, whose objective function is processing efficiency and cost.And the best process parameters are calculated by using genetic algorithm.5) A process parameter database system for centrifugal impeller blades five-axis NCmilling is developed in VC++, ACCESS and CBR, which can provide appropriate suggestionfor choosing process parameters.In conclusion, the researches in this paper provide a scientific solution to achieve thehigh-efficiency and high-quality centrifugal impeller blades five-axis NC machining. And thetheory foundation is established to improve the overall machining process level of five-axisNC milling centrifugal impeller blades.