Design of internal flow passage of internal chip removal drill for suction-type internal chip removal system

Currently, hole making processes in carbon fiber reinforced polymers (CFRP) generate powdered chips that cannot be automatically recovered in real time. The present work attempts to solve this problem using a new drilling-chip removal system called the suction-type internal chip removal system. It can discharge the powdery chips generated in the CFRP hole making process in a timely and effective manner during the drilling process. Based on the requirements of the drill bit used in this system, the following studies are carried out in this work: (1) Using statistical methods, the chips produced in CFRP hole making were classified, the chip distribution was analyzed, and the study of the influencing factors of chip size were completed; (2) based on these studies and the gas–solid two-phase fluid mechanics, a FLUENT simulation is used to define the center distance and center angle of the inner runner for the design of the drill bit. The influence of the center distance of the inner runner, the center angle of the inner runner, and the cross-sectional shape of the inner runner on the chip removal effect of the inner runner of the tool is given. Finally, by fabricating the chip removal system and drill, the correctness of the internal flow channel structure design of the internal chip removal drill was verified.