Effect of thrust and torque exerted during drilling to optimize exit burr height and thickness by choosing variable drill bit geometry: A simplified theoretical model approach

Abstract

In precision manufacturing, especially in making of holes on the parts during drilling process for precision assembling of parts facing problems with burr formation. Drilling is one of the finishing operations in the production cycle, removal of burrs during drilling process is a time consuming and non-value added process to the manufacturing sector. In this paper, we developed an analytical models for thrust force, torque and burr size with variable clearance angle of drill bit geometry especially for Aluminium alloys used for automotive applications. An analytical model results were obtained by writing a code in MATLAB @ 2010 software for aluminium alloy series such as Al 6061, Al 2014 and Al 7075. In an economic front, de-veloped mathematical models are benefitted to reduce experimentation, these results reveal that at the beginning of the drilled hole due to indentation of chisel edge, more thrust and torque was identified, beyond that suddenly thrust force was lowered, cutting forces by the lip edges were increased from beginning of the process to progress of drilling process. The proposed model approach is helpful to the budding entrepreneurs in the related areas to select optimal combination of drilling parameters to attain multiple performance characteristics of responses especially in burr size to prevent the post finishing operations up to certain extent.

Keywords

• Drilling
• Aluminium alloys
• Burr formation
• Thrust force
• Torque
• Analytical modelling