On the Development of Multi-Edge Cutting Tools for BTA Deep-Hole Machining

Abstract

The design concept and the analysis of multi-edge BTA deep-hole machining tools are presented. The main feature of the design is that the tool cutting edges are unsymmetrically located on the boring head. This provides a stabilizing cutting force resultant necessary for self-guidance of the boring tool. The role of this stabilizing force for machining accurate holes of high length-to-diameter ratio is explained and demonstrated by examples. The principles of tool self-guidance and the range of application for various drilling methods are discussed and examples are given. The results show that, besides achieving higher material removal rate, the use of unsymmetrical multi-edge cutting tools provides similar performance to that of single cutting-edge boring tools in terms of tool stability and bore accuracy. Results also show that by controlling the cutting force resultant at a predetermined value based on feed rate, cutting conditions and tool geometry, a full-film lubrication at wear-pads of the boring head can be insured during the boring operation.