Mechanical Analysis And Simulations Of Temperature Field And Fluid Property Of Deephole Drilling Based On BTA

BTA(Boring and Trepanning Association)Deep Hole Drilling(a single tube with two holes of the BTA deep hole drilling system)is one of the most important deep processing methods,which is widely used in the manufacturing fields of spaceflight,navigation,arms industry and nuclear vessel etc.accou nting for about 25% of the market in machining manufacturing share.There are the processing advantages for the large length to diameter ratio,ultra-hard and ultra-soft materials.There are the related problems of the BTA deep hole drilling work as follows: in enclosed processing the workpiece internal trajectory cannot be observed,special kind of drill bit,drill pipe internal chip and heat from the axial cutting force removed mainly by the flushing fluid may make the midway stop for cooling,in the fluid of high strength,high temperature and turbulence the whole BTA drill bit is easy to make the diamond blade and the engraved embrittlement crack artifact and to seriously reduce the service life of the bit,highly turbulent conditions of flushing fluid,on the top of the bit system caused by the kinetic energy of the greatly reduced,and with the rotation of the flushing fluid and chip,gravity,eddy current effect.These produce the so-called "chip removal of heat removal,classic problem.In this paper,based on the working principle of BTA drill and the axial cutting force work into cutting heat,cutting heat distributed mainly by the removable chip,the change of cutting temperature indirectly reflecting the chip removal condition,the revised BTA drill model is established to improve the efficiency of chip removal and heat removal.By the finite element analysis software the mechanics,temperature field and fluid field are analysed.To improve the efficiency of chip removal and heat removal in the revised BTA drill,the relevant theoretical research work has been done as follow:Firstly,on the basis of force analysis of the traditional BTA drill bit,the reasons of the low efficiency of chip removal and heat removal are found out.This paper puts forward suggestions and improving bit structure.Trapezoidal static pressure tank and grooves are added on the fringes of the drill bit and the drill throat to the size of the space layout is re-designed to obtain the new structure of BTA deep hole drill.Solid Works three-dimensional models of the traditional and the revised BTA drill are established on the basis of parameters from industry.Secondly,by using finite element software ANSYS static analysis,modal analysis and fatigue analysis,and simulation of the revised BTA drill are carried out to research the impact of trapezoidal static pressure tank and grooves.Thirdly,by the use of Deform-3D force,the finite element analysis software,the influence of the load,the cutting chips and the cutting heat on chip removal and heat removal is analysed.Through ANSYS fluent fluid analysis,the simulation results of the traditional drill and the BTA drill after adding trapezoidal static pressure tank internal and external flow characteristic are comparatively analysed.According to the resulting velocity field,pressure field,temperature field,it is verified that the improved BTA deep hole drill increases the capability of chip removal and heat removal.Finally,the test results and the theoretical conclusions are consistent.That theory,the correctness and validity of the results in this paper.In solving the chip removal and heat removal,on the way of research of this paper to guide the actual production of the BTA deep hole drilling and academic research has a certain engineering and academic value.