NC Machining Tool Path Planning Of The Fan Blisk And Software Redevelopment

As an important part of aero-engine,fan blisk has the characteristics of large distortion and narrow channel space,which bring difficulties to its NC machining.In view of this,The main accomplishments in this dissertation can be concluded as follows:(1)NC machining strategy for compound surface of fan blisk.NC machining strategy for compound surface is proposed aiming at the characteristics of blade of fan blisk with large aspect ratio and insufficient tool accessibility during machining.Firstly,multiple surfaces on adjacent blades are processed as a compound surface.And then,according to the specific processing requirements of compound surface and using the algorithm designed in this dissertation,the boundary lines are generated on the compound surface.Based on the boundary lines,the compound surface is divided into six regions for NC machining path planning.Finally the process of each region of the compound surface is determined.(2)Tool path planning for compound surface of fan blisk.Firstly,the cutter contact point path is planned according to the composition characteristics of six regions.Then the offset cutter contact point path is generated.After that,the offset cutter contact point path is discretized,and all cutter contact points for compound surface machining are obtained.Afterwards the cutter location points can be calculated from the cutter contact points,according to the structure of ball-end cutter.The next step is that the cutter axis vector is determined by the title angle and the yaw angle.Besides,an overall tool orientation planning strategy is proposed,which keeps the title angle and the yaw angle of the same cutting line unchanged.Finally the tool orientation without interference on the combined surface is obtained through being adjusted according to the actual processing situation of each region.(3)Development of fan blisk finish machining module based on UG/Open.According to the tool path planning theory for compound surface of blisk in this dissertation,using UG secondary development tool UG/Open and C++ language to program,the fan blisk machining module embedded in UG software interface is developed,and the NC machining tool path of fan blisk model is automatically generated?(4)The simulation and experiment of fan blisk NC machining.Firstly,the tool path of rough and semi-finish machining of fan blisk is generated by the UG software,and then the tool path of finish machining is generated by fan blisk finish machining module developed in this dissertation.Afterwards,the post-processing calculating is carried out according to the characteristics of the CNC system of the machine tool.Then the NC processing program of each process is obtained.Next,the Vericut software is used to simulate the machining of fan blisk.After confirming that the simulation is correct,a machining experiment is performed on the five-axis NC machining center of Beijing Jiaotong University,which verifies the feasibility of the NC machining path planning theory studied in this dissertation.