Research On Key Technology Of Blisk NC Belt Grinding

As a new type of bladed-disk structure,the blisk is the main component of the aeroengine rotor.Meanwhile,as a high-precision component,it requires a very high surface quality.The surface quality of the disk directly affects both the performance and the service life of aeroengines.After the blisk has been fine-milled,the lateral blade grains remain on the blade.In order to remove the remaining milling grains on the blade surface,the surface of the blisk needs to be further polished.At present,the hand-polished method is commonly used for polishing the surface of the blisk in China.However,there are some major disadvantages to the hand-polished method,for instance poor surface consistency,insufficient smoothness,and long processing time.With the rapid development of modern industry and scientific and technological progress,the hand-polished method can no longer meet the requirements of the engine manufacturing industry.Therefore,in order to improve the blisk surface grinding quality and efficiency,it is particularly necessary to develop advanced blisk CNC grinding equipment and technology to replace the backward hand-polished method.This paper takes the aeroengine blisk as the research object,and does the blisk grinding experiment with a special CNC abrasive belt grinding machine.This paper uses the method of CNC abrasive belt grinding method,carries out research work with key technologies such as the blisk trajectory planning,machine tool motion solution,process plan and interference processing,separately grinds the profile,root,inlet and exhaust sides of the blisk.The purpose of this paper is to verify the feasibility and correctness of the blisk CNC abrasive belt grinding and provide important reference data and technical basis for CNC grinding of complex surface parts like the blisk.The main innovations and research contents of this paper are as follows:1.According to the characteristics of the blisk structure,a method of the blisk CNC abrasive belt grinding was proposed,at the same time,the main system of the blisk grinding was studied.The flexible grinding technology was analyzed,and on this basis,the shaft structure of the CNC grinding machine and the polishing tools were discussed.Based on the above studies,the blisk grinding plan was finalized.2.Through the analysis of the characteristics of each part of the blisk,different methods were used to plan the blisk grinding process trajectory,and correspondingly,the processing paths of the profile,root,inlet and exhaust sides were formulated.According to the process trajectory,the step length,line spacing,etc.werecalculated,and the machining feed parameters were determined.By solving the motion of the CNC abrasive belt grinding machine,the feasibility of the blisk grinding was verified.3.Combined with the actual grinding requirements of the blisk,the overall grinding process plan of the blisk was proposed.At the same time,according to the principle of the blisk grinding,the main types of interference in the blisk grinding process were analyzed,and different interference characteristics were studied.Based on this,a method of dynamic adjustment of the tool shaft to prevent interference was proposed,by solving the position and orientation of the tool shaft and the optimal swing angle to solve the problem of interference in the machining process.4.Established a simulation environment for CNC abrasive belt grinding machine,combined with self-developed integrated grinding software,to verify the feasibility of the grinding process.Combining the processing parameters,the grinding experiment was performed on the CNC abrasive belt polishing grinding machine for the blisk.The result indicated that the surface quality can meet the requirements of the aeroengine blisk grinding and also verified the reliability of the key technology of the CNC abrasive belt grinding.Meanwhile,it provided a technical basis for the CNC grinding of the blisk technology to replace manual polishing.