Investigation of chip jamming in deep-hole drilling

Abstract

In this paper, we show the recent progress and first insights in modeling chip jamming in the deep-hole drilling process. Chip jamming is a significant problem when chips wrap around the tool, leading to marks on the borehole wall and an increased drilling torque causing sudden tool failure. Recent investigations focused on chip evacuation and fluid distribution along the cutting edge. This work extends the existing models by adding an artificial barrier in the chip flute. This barrier approximates a chip jammed between the drill shaft and the borehole wall. In the first approach, this barrier blocks the complete chip flute but allows fluid to pass, only blocking the chips from their evacuation. In the second approach presented, a non-permeable artificial barrier partially blocks the chip flute. Furthermore, we show the validation of the model and evaluate the assumption of rigid chips for the chip evacuation as they are applied in earlier investigations. Finally, we show the deformation of the chip as it blocks the fluid from its evacuation and the impact on the fluid flow during the process.