On Machine Inspection And Geometry Adaptive Grinding Method For Aeroengine Blades

As a key component of an aero engine,the processing quality of blades has an important impact on the efficiency and performance of the engine,and in severe cases,it will cause fatal engine failures.In order to improve the surface quality of the blade,belt grinding is usually used as the finishing process of the blade.However,the abrasive belt grinding uses a soft wheel-shaped abrasive tool.During the grinding process,the abrasive belt is in elastic contact with the blade,and precise removal of materials cannot be achieved through accurate tool position control.Therefore,the traditional abrasive belt grinding and polishing process is mainly used to improve the surface quality of the blade,and it is difficult to reliably guarantee the accuracy and consistency of the blade profile,and cannot meet the needs of new aeroengines for high-quality and mass-production blades.Aiming at the problem that the profile accuracy cannot be accurately controlled in the current blade abrasive belt grinding process,this paper proposes an adaptive CNC abrasive belt grinding method for blade geometric deviation based on coordinate measurement,that is,on-machine measurement-geometric deviation model establishment-material Eliminate the construction of the predictive model—the integrated technical route of adaptive grinding and processing.The main research work carried out in the thesis is as follows:First,build the overall plan of blade on-machine inspection,and compare the two methods of calibration ball calibration and standard cylindrical calibration,and propose two calibrations of the standard cylindrical symmetry angle to complete the high-precision calibration of the probe.The six-point iterative method was used to establish the measurement coordinate system,and the process and results of the establishment of the three-coordinate measurement coordinate system were compared to verify the accuracy of the on-machine inspection measurement coordinate system established by the iterative method.Secondly,the measurement section line is planned by the contour method,and on this basis,the chord height method is used to adaptively generate the reasonable arrangement of the measurement coordinate points,and the linked list insertion method is used to optimize the order of the measurement points.Research on measurement data processing methods include probe radius compensation and correct ordering of measurement data.According to the measurement results,iterative closest point(ICP)optimal matching algorithm is used to best fit the measurement data point set and the theoretical model.Then,the adaptive abrasive belt grinding method of blade geometric deviation is studied.Aiming at the uneven distribution of the blade profile surface grinding allowance,an adaptive tool path planning and process parameter control based on the parameterized material removal prediction model are proposed.method.The orthogonal experiment method is used to test the removal of blade abrasive belt grinding material within the range of typical abrasive belt grinding process parameters,and the influence of each process parameter on the removal of blade material is analyzed.Finally,a prediction model for the amount of material removal of the blade was established,and the accuracy of the prediction model was verified by test data.Finally,the engineering application of blade adaptive belt grinding method based on coordinate measurement is carried out.Integrate the above research methods and key technologies,develop a software system for blade on-machine detection and adaptive belt grinding,and apply the software system to a blade CNC belt grinder to carry out an adaptive grinding experiment of a certain type of blade.The experimental results show that the blade self-adaptive CNC belt grinding method studied in this paper can better ensure the blade profile accuracy.