Research On The Key Technology Of Robot Polishing For Aero Engine Blisk

To achieve the purpose of improving aero engine thrust weight ratio,the blisk integrates the blade and wheel-disc through the application of advanced technology,which can eliminate the traditional blades of tenon joint and mortise lock and redundant structure.However,due to the blisk in the existence of the twisted,and has a thin wall,wide-chord,bending and other complex geometric characteristics of the whole process,resulting in the process of abrasive and the workpiece prone to interference or collision,even cause the expensive blisk scrapped.So the blisk manufacturing in the planning and collision detection technology have put forward higher requirements.At present,the domestic blisk finishing is still mainly rely on manual polishing,but because of its low efficiency,grinding allowance uneven problems that make it difficult to adapt to the new aero engine development and production needs.In order to meet the requirements of thrust weight ratio and reliability of aviation engine to improve the quality and processing efficiency of blisk manufacturing,this paper,on the basis of deeply researching and analyzing the present situation of blisk grinding and polishing technology both here and abroad.Aiming at the trajectory planning and interference detection in the blisk grinding,this paper has laid a technical foundation for the realization of the blisk with high precision,high efficiency and high quality grinding and polishing.The main contents of this paper are as follows:(1)This paper analyzes the advantages and the importance of the application of the blisk in the field of aero engine,and investigates the research and application of industrial robots in grinding and polishing in recent years,and demonstrates that the robot advantages and characteristics in the blisk grinding and polishing application.(2)Based on the analysis of trajectory planning methods such as traditional parameters and equal steps,the dichotomy method in the equal parameter trajectory planning method is improved.The size of the contact wheel during processing is optimized by genetic algorithm,and a spiral trajectory planning method and an adaptive trajectory planning method are proposed and implemented for the blade of the blisk.(3)Based on the hierarchical OBB modeling of the abrasive tool and the space octree segmentation of the workpiece,a separation axis collision detection algorithm is adopted to realize the off-line collision detection and avoidance processing of the blisk grinding and polishing program.(4)The kinematics modeling of the KUKA240-2 type robot is carried out by using the D-H method,and the inverse formula of the joint angle of the robot is deduced.The kinematic inverse of the machining path of blisk is completed and simulated.Finally,the robot is used to simulate the blisk grinding process.The simulation results verify the correctness of the grinding wheel selection algorithm,trajectory planning method and collision detection technique proposed in this paper.