Research On Five-Axis Machining Error Analysis And Virtual Measurement Technology For Centrifugal Impeller Blades

As a typical part of complex surfaces, centrifugal impellers are widely used inaero-engines. With the rapid development of aero-space industry in China, processing qualityof impellers is requested much higher. At present, our country can independently develops aseries of aero-engines, such as Tai hang, Eruption-1A, Red flag-2etc. However, comparedwith sophisticated machining technologies for impeller in developed countries, our countryhas a great gap. The major reason is that there are a lot of factors that influence machiningprecision of centrifugal impeller blades. For instance, the machining and measuringtechnologies for centrifugal impeller blades are extremely backward in our country. Thesimple geometry tool path planning is just applied in the blades actual processing. Machiningdeflection errors and machining errors lack of systematic research and analysis. In addition, italso lacks the effective means to measure machining errors. So, it becomes an importantproject that how to establish effective methods of analyzing and measuring machining errorsfor centrifugal impeller blades to achieve reliable predication and effective measuring onmachining errors in effective and precision machining of centrifugal impeller. Based on themulti-body system theory, cutting physical simulation, virtual measurement, the influence lawof machining deflection errors and machine errors on machining precision of the centrifugalimpeller blades has been explored, and the efficient virtual measurement method ofmachining errors has also been established. The main works in this thesis can be concluded asthe following：1) The entity model of tapered helical ball end mill is established by using the UG/Open Grip. And then, physical simulation for centrifugal impeller blades machining processhas been carried out to obtain the milling force numerical solutions by using AdvantEdgeFEM.2) Based on the step1), the machining simulation model of centrifugal impeller bladesis established by using multi-load step technology of ANSYS software. By analyzing itsdistribution law of machining deflection, an effective compensation method for machiningdeflection errors of centrifugal impeller blades is realized.3) The error profile vector equations of centrifugal impeller blades that machine toolsoriginal errors influence is included are built by using multi-body system theory. On which,the effective profile error compensation is achieved by analyzing comprehensive influence ofthe original errors on profile surface errors of centrifugal impeller blades. 4) The virtual measurement method of centrifugal impeller blade machining errors isput forward based on virtual measurement principle. Virtual measurement platform isdeveloped for machining errors by using UG. The machining errors resulting from singlepoint offset machining method and three-point offset machining method respectively aremeasured. The measuring results coincide to the literature’s theoretical values, which indicatethat the virtual measurement method is reliable and the platform is valid.In conclusion, the researches provide an effective solution to achieve efficient analysis,measurement and compensation on machining errors of five-axis centrifugal impeller blades,also lays theoretical basis for improving machining precision and machining efficiency.