Study On Drilling Simulation And Experiment Of Internal Cooled Drill

Internal cooled drill machining normally deep hole without retract has high processing efficiency and good processing quality of hole wall.In this way,we can save some complicated processing technic,and ensure the machining accuracy,so it is so widely popular in machining normally deep hole.The western industrialized countries do much research on the internal cooled drill earlier,and have good success.We do little research on the cutting performance of internal cooled drill and drilling mechanism at the early stage,and twist drill manufactured by most domestic manufactures is still external structure.This article uses finite element simulation and experiment to study the cutting performance at different cutting parameters.In order to make the simulation process closer to the actual processing,in this paper we use Johnson-Cook shear failure criterion as the separation criterion and simulate forced convection heat transfer processing in the condition of internal cooling by the definition of the film heat transfer coefficient.Assign friction heat partition factor between tool and chip and calculate the thermal exchange coefficient.Then the influence of internal cooling conditions on the temperature of the cutting layer is determined by simulation of cutting layer to be processed heat transfer.The force and temperature data of the internal cooled twist drill have been obtained by the dynamic finite element simulation of the drilling process on different cutting parameters and analyzed to study the trend.Under the condition of the maximum cutting speed,we do some research on the unstable drilling torque phenomenon with the increase of drilling depth.Because the cutting speed has importance impact to the drilling temperature,the temperature distribution on the cutting edge has been studied based on the discrete element method.The drilling axial force and torque have been measured by drilling on the parameters in the cutting simulation to validate simulation feasibility by compared with the result of the simulation.The tool cutting edge wear phenomenon is analyzed and discussed based on the finite element analysis result of the temperature distribution on the cutting edge,and put forward the improvement scheme of cutting edge structure.