Design Optimization Of Guide Block For BTA Deep Hole Drilling

BTA(Boring and Trepanning Association)deep hole drilling technology can be widely used in aerospace,military,petroleum,machinery and other industries.In the process of deep hole drilling,the guide block acts as a guide,supporting tool,balancing cutting force and extruding the polished machined surface.The guide block structure,position distribution,size parameters and coating treatment have great influence on the performance of BTA deep hole drilling guide block.Therefore,this paper launches the following research:Firstly,aiming at the problem of insufficient stability in deep hole manufacturing,the stability of deep hole drilling system is studied.The mechanical model of BTA deep hole drilling is established,and the influence of drill force and drilling force on the stability of the drill bit is analyzed from the drilling force.The dynamic model of drill pipe is established,and the frequency response function is obtained by dynamic analysis of drill pipe,which provides theoretical support for the study of drilling system stability.Secondly,in order to improve the stability of the machining system,this paper takes the guide block shape as the breakthrough point to analyze the force state of the trapezoidal guide block and the spiral guide block.Considering the pressure effect of hydraulic oil on the guide block,the influence of the shape of the guide block on the force is analyzed theoretically,which lays the foundation for the simulation and experiment.What is more,starting from the BTA deep hole drilling model simulation by drilling simulation,from drilling force variation and torque variation,the blade temperature distribution and tool wear state,when the study guide block designed for trapezoidal and spiral,the stability of machining system,provide technical support for improvement guide block.At last,according to the influence rule of the guide block geometry on thedrilling system,the drilling test of different structure guide block is carried out.Through the analysis of drilling force,drilling vibration,surface roughness,tool wear and chip shape and other factors,the results show that the spiral guide block can improve the stability of the system.At the same time,the spiral guide block can improve the surface roughness of the workpiece and reduce the wear value of deep hole drill.The above research provides technical guidance for the design of BTA deep hole drilling guide block.To summarize,the value of this research lies with the study of three aspects,i.e.theoretical analysis,finite element simulation and experimental verification.As well as,it finally has completed the optimization of the guide block's shape which becomes the most important significant to improve the stability of the deep hole drilling system and the surface quality of the inner hole.