NC Machining Tool Path Planning Of The Blisk And Software Development

As one of the key structural components of aero engine,the big-twisted blisk is a typical complex surface parts,and the NC machining of which has always been the key and difficult point of aviation manufacturing industry.In order to solve the problem of the path planning for big-twisted blisk,the following work has been done in this thesis:(1)Cutter location points planning for composed surface of blisk.According to the characteristics of the long blade of big-twisted blisk and the deformation of tool during machining,a new composed surface machining method for the blisk was proposed.And according to the characteristics of thin blade edge and large variation of curvature,the geodesic line method was proposed to plan the cutter location points of blade edge area in order to avoid the abrupt change of the tool orientation.For the flow channel region,a cross section method was proposed to connect the machining paths on both sides of this area,and to ensure the smooth transition of machining paths on junction area of composed surface.(2)Tool axis vector planning for composed surface of blisk.For planning tool axis vector of composed surface,an overall planning idea that the tool needs to be perpendicular to the feed direction of the first cutting surface was proposed by analyzing the characteristics of the machining path of the composed surface.On this basis,the local coordinate system for the tool axis vector planning of composed surface was established,so that the tool axis vector can be adjusted by changing the angle parameters in the local coordinate system.(3)Development of NC programming software based on Rhino.Firstly,the structure of the CNC machine used in the experiment was analyzed,and by combining it with the practical motion principle of machining,the corresponding post processing algorithm was obtained.Then based on the Rhino software platform,the NC programming software of the blisk was developed.After inputting the necessary parameters,it can automatically complete the modeling of the blisk,the planning of the cutter location points and the tool axis vector,and the generation of NC machining code.(4)The simulation and experiment of the blisk machining.Firstly,UG was used to generate the rough and semi finish machining code,and then the blisk NC machining software was used to generate finish machining code,and the correctness of all machining code was verified by Vericut simulation.At last the effectiveness of the tool path planning method was verified by five axis NC machining experiment.