Cutting process in non-step drilling of deep hole with tool wear progress

Abstract

Non-step drillings of deep holes with twist drill are required to achieve high production rates in machine shops. However, tool breakage sometimes occurs due to chip clogging in the holes. The surface finish is also deteriorated by chip scratching. These machining troubles are induced by the change in the chip flow accompanied by tool wear progress. This paper discusses the cutting process in drillings of deep holes in terms of the geometrical change in the cutting edge with the tool wear. The chip flows towards the radial direction with the change in the edge shape when the tool wear increases. Then, the chip clogging in the hole induces a large oscillation in the cutting force. The chip flow is also analyzed with the change in the edge shape due to the tool wear by the energy-based force simulation.

Keywords

• cutting force
• tool wear
• drilling
• chip flow
• chip clogging