Abstract: Aiming at the problems of cooling and chip removal in through-hole dry milling, an innovative process scheme for cooling and chip removal by using three-jaw chuck to clamp workpiece and injecting pressure gas from the bottom of the hole into the processing area was proposed. Three-dimensional turbulence model of milling area was established by using three-dimensional accurate model of integral vertical milling cutter. Based on standard k～ε turbulence model and MRF method in multiple rotating coordinate system of Fluent software, the pressure and velocity fields in the milling zone were compared and analyzed when the air flow was ejected from the center hole of the milling cutter and from the five angles of the bottom of the hole. The results indicate that the gas pressure distribution near the milling cutter, the spiral wall of the chip-containing groove and the spiral wall of the circumferential edge, and the gas velocity of the chip-containing groove and the spiral wall of the circumferential edge can effectively improve the cooling and chip removal conditions in the processing area when the gas flow is ejected from the direction of deviation from the hole bottom diameter 15° and depart from the chip holder groove. The research results provide a theoretical basis for optimizing the air injection angle and flow field in through-hole dry milling zone.
Key words: dry milling; green cutting; airflow; pressure field; velocity field