Research On Six-axis NC Technology Of Ultrasonic-assisted Machining Of Honeycomb Curved Parts

Ultrasonic-assisted cutting Nomex honeycomb material sits with natural advantages such as good processing surface quality and small cutting force compared with traditional milling,but the research of ultrasonic processing technology in China is still in the exploratory stage,especially in the field of processing technology,and has not yet formed a complete process path planning method,so the processing efficiency is still low.The construction of process parameter database is also in its infancy.Starting with the characteristics of ultrasonic tool,honeycomb material characteristics and the complex surface characteristics of parts,this paper starts the research of six-axis CNC ultrasonic auxiliary cutting process,and the precision requirement of honeycomb parts is low,so this topic focuses on the study and improves the roughing efficiency of ultrasonic auxiliary cutting,as well as the efficiency of process planning and post-processing.The main research work and results are as follows:1.Carry out the research of ultrasonic auxiliary cutting process planning,establish the cutting efficiency model and select the machining roughing processes of "V" shape cutting.By studying the characteristics of typical honeycomb parts in the aerospace industry,the structural characteristics of ultrasonic tools and the form of motion,a variety of cutting processes based on ultrasonic tools are obtained.The system process design is carried out for the two rough machining processes and the finishing process of the machining processes of "V" shape cutting and the machining processes of rectangular cutting.Then the two roughing processes are optimized,and the 2.5-dimensional residual height model is established for each of them.Then the tooling point counting model and the cutting efficiency model are introduced,and the machining efficiency of the two is visually compared.Finally,the machining processes of "V" shape cutting is preferred as an efficient ultrasonic assisted cutting roughing process.2.The process parameters of ultrasonic assisted cutting were studied,and the three-dimensional surface residual height model,tool interference model and ACU axis static angle model were established to optimize the process parameters.Firstly,according to the cutting characteristics of the ultrasonic the triangular-blade,the depth of cut and the step model with the forward rake angle and the side swing angle are obtained under the general process conditions.According to the characteristics of the machining processes of "V" shape cutting,the special depth of cut model in the process is obtained.On this basis,two residual height models are obtained for two typical residual height types.The model shows that the residual height maxima can be obtained when the surface tilt angle y of the part is equal to the side swing angle ?.Secondly,through the analysis of the cutting method of ultrasonic triangular-blade knife and disc-blade,the global interference judgment model and interference avoidance method of the triangular-blade and the disc-blade in the process of self-planning tool position are obtained,and the preliminary planning process using CAM system is obtained.The knife edge interference process and interference avoidance method that occurs in straight edge cutters.Finally,the static angle relationship model between the ultrasonic tool forward angle and the side swing angle and the ACU rotary shaft of the six-axis CNC gantry machine with ultrasonic spindle is established.3.Process path realization:The tool path planning of ultrasonic assisted cutting process is carried out by combining CAM system with self-developed secondary post-processing module.Firstly,UGCAM is used to plan the tool path for the machining processes of "V" shape cutting,and a preliminary three-axis NC code is generated.Secondly,according to the process characteristics of the ultrasonic straight edge knife in the machining processes of "V" shape cutting,the NC code is subjected to secondary post-processing to generate a six-axis NC code containing the information of the ultrasonic spindle motion,and the secondary post-processing module includes the knife position.Sequential secondary programming,rotation axis command angle research,lifting knife information research and cutting tool path research four key technologies.Finally,the NC code after the adaptation was successfully verified by Vericut six-axis CNC machine motion simulation.