Tool-path Planning Research For Rough Machining Of Impeller Channel Based On NX

As a core component of turbine machinery,the integral impeller plays a vital role in various fields of aviation,aerospace,shipping,chemical industry,etc.And the manufacturing and processing of impellers could reflect the modernization level of a country.As the first step of machining the impeller,the rough machining of the impeller channel not only needs to ensure the machining efficiency,but also has certain requirements on the machining quality of spare parts' surface.Therefore,the rough machining tool path planning of the impeller channel has always been an important research topic.At the same time,because the domestic research institutions have little technical reserves related to CAD / CAM software for impeller tool-path planning,it is also of great significance to use the secondary development function of NX to develop the CAM module for rough machining of the impeller channel.In view of the above situation,this article aims at analyzing the semi-open integral impeller,mainly from the following two aspects:In terms of tool-path planning,a uniform layering processing strategy with equal depth of cut is firstly proposed,and according to the characteristics of the width variation of the impeller channel,the determination method of each layered surface and its boundary when milling with a flat-bottomed tool is given,by analyzing the geometry and curvature changes of any surface layer,on the basis of optimizing the traditional equal-residual height method,a tool-path planning method based on the nature of the gyroscopic surface is proposed to solve the problem of redundant tool path and huge calculation when planning the path with the traditional layered method.Moreover,combining the determination of the tool axis vector and the tool interference,a tool axis vector optimization method is proposed to make the tool transition in the interference area smoother.In terms of software development,the above algorithm is realized with the help of the secondary development function of NX,and the entire tool position planning program is built.The program development is mainly divided into two parts: The first part is the design of the UI interface.The main parameters are the modeling parameters of the impeller model,tool radius,residual height,finishing allowance and layered cutting depth;the second part is the realization of the main program.First,determine each layered surface according to the modeling parameters and layered cutting depth,then determine the roughing boundary on each layered surface according to the tool radius and finishing allowance,and on the layered surface with the determined boundary,select a reasonable initial path,and plan the tool path according to the principle of a certain residual height of the adjacent path,then disperse the planned path to obtain the cutter contact point.In order to avoid interference,the tool axis vector is planned and optimized at each cutter contact point,finally,convert the non-interference cutter contact point into cutter location point and export the file.Finally,the tool position file generated by the above program is imported into NX's cutting module,and the post-processing function of the software is used to perform tool path visualization and dynamic simulation,which verifies the correctness of the above tool-path planning method.