Abstract: Aiming at the problems of low chip removal efficiency and easy chip plugging at the throat of drill bit during deep hole machining, the flow process and flow characteristics of the coolant in the throat of the bit and the cooling section exit velocity of the BTA cooling system were studied. Based on computational fluid dynamics (CFD) and jet entrainment, a new type of BTA deep hole drill throat structure was proposed. After analyzing the pressure and flow parameters, the turbulence intenisty and dissipation rate of the finite element model were revised. The chip removal capacity of two drill throat structures was compared and the average outflow velocity of coolant outlet section was measured on the modified finite element coolant system simulation model. The results indicate that the cooling system composed of a new type of deephole drill with a diameter of 38 mm BTA with throat structure increases the average speed of outflow from the coolant outlet section by 12.6%, and also improves the chip removal capacity of the coolant system.
Key words: deep hole machining; chip removal efficiency; BTA deep hole drilling; throat structure