The effects of dub-off angle on chip evacuation in single-lip deep hole gun drilling
Tnay, Guan Leong
Woon, Keng Soon
Yeo, Swee Hock
Date of Issue2016
School of Mechanical and Aerospace Engineering
Singapore Institute of Manufacturing Technology
Without proper chip evacuation, gun drills will fail under intense thermal and mechanical loading during deep hole drilling of high temperature superalloys like Inconel 718. In gundrilling, the efficiency in evacuating chips is governed by the geometry of gun drills that defines the hydraulic boundary conditions for coolant and chip flow. In this paper, we propose a novel computational fluid dynamics (CFD) model that is capable to simulate and quantify the chip transportation behavior under high pressure coolant for drill geometry optimization. This is demonstrated through a case study on improving the shoulder dub-off design of commercial gun drills, which have a high tendency in trapping chips at the hole bottom. A more effective design criterion for the shoulder dub-off is thus proposed.
Deep hole gundrilling
International Journal of Machine Tools and Manufacture
© 2016 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by International Journal of Machine Tools and Manufacture, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.ijmachtools.2016.05.008].