Cutting Capability of Microdrills in Nonstep Drilling

Abstract

There is a high demand for microdrilling processes to drill microholes with diameters equal to or less than 0.2 mm for use in fuel injection nozzles. In this study, nonstep drilling methods are developed for high-efficiency processing. Herein, the effects of the cutting oil supply method and the drill’s feed rate on the developed thrust force and torque during drilling are investigated. Accordingly, it is shown that drop supply of the cutting oil is the optimal method for nonstep drilling because the oil is sucked into the microhole. Furthermore, a high-feed rate is preferred because it produces continuous chips.^*

^* This paper is a translation with revision of the paper: M. Uchiyama and N. Sakata, “Cutting capability of micro drills in non-step drilling 1st report: Optimization of cutting oil supply and drill feed,” J. of the Japan Society for Abrasive Technology, Vol.59, Issue 1, pp. 27-31, doi: 10.11420/jsat.59.27, 2015 (in Japanese).