Analysis of the cooling lubricant flow during ejector deep hole drilling by in-process volume flow and pressure measurements

Abstract

Ejector deep hole drilling is required for a variety of drilling applications with length-to-diameter-ratios larger than l/D > 10 and high quality demands, e.g. on roundness, diameter accuracy and surface quality. The ejector effect is essential for the process and decisive for a stable ejector deep hole drilling process by supplying the working zone with cutting fluid. In order to realize an enhanced fundamental understanding of the ejector effect with its process-typical specialties, a demanding experimental setup for in-process fluid volume flow measurement is developed. On the basis of the resulting deeper process understanding of the cooling lubricant behavior during ejector deep drilling, new optimization strategies for increasing deep hole drilling efficiency in the industry can be achieved.