Research And Development Of Rapid Programming System For NC Machining Of Aircraft Steering Gear Shell

The aircraft steering gear is the executive part to control the rotation of the aircraft steering surface.The steering gear shell is an important part of the steering gear,which has the characteristics of complex structure,many machining features and high precision requirements.All kinds of features of the steering gear shell are usually processed by numerical control.The efficiency and quality stability of numerical control programming will directly affect the production cycle and quality of the steering gear shell.At present,in the manufacturing enterprise of the steering gear shell,the programmer manually compiles the numerical control program of the steering gear shell in the software according to their own experience,which has a large amount of repetitive work and low programming efficiency.Many excellent programming knowledge cannot be effectively shared and reused,thus affecting the stability of the programming quality.In view of the above problems,this paper studies the rapid NC programming system of the aircraft steering gear shell.By analyzing the process characteristics of different features of the steering gear shell,the solution of the rapid NC programming is given.The research contents are as follows:(1)The scheme design of the fast programming system for the numerical control machining of the steering gear shell.Combined with the needs of users,the system development technology proposal is put forward,and the overall framework of the system is constructed.The function and workflow of each module are analyzed,and the key technologies needed to realize the system development are also analyzed.(2)Hole feature recognition of steering gear shell.According to the structural characteristics of typical hole machining features,the definition and classification are carried out,and the invariant machining features are expressed and stored by using the self-defined attribute adjacency graph,and identified based on the subgraph isomorphism algorithm.In addition,based on the geometric topological relationship of the model and the structural characteristics of the valve sleeve hole,a recognition method for the variable complex multi-level features is proposed.(3)Rapid generation of tool path for numerical control machining of steering gear shell.In this paper,the processing technology of the steering gear case in the enterprise is summarized.For the features of hole,the automatic process decision-making and tool path generation technology based on the machine feature are studied and the machining knowledge base is constructed.For the shape feature,the NC programming technology based on the machining template is used to realize the rapid generation of the machining tool path of the steering gear shell.(4)The development of the rapid programming system for the numerical control machining of aircraft steering gear shell.Based on NX8.5,the rapid NC programming system of aircraft steering gear shell has been developed,which has been verified in an aviation manufacturing enterprise and achieved good results.