Control System for Roundness Error of Holes in Deep Drilling

Abstract

As regards the machining accuracy on deep drilling, straightness and roundness are generally discussed. The straightness error is caused by the axial deviation of hole, and the roundness error results from the occurrence of polygonal profile. The purpose of this study is to improve the roundness. To put it more concretely, we suggest the measuring system to evaluate hole profile in drilling process and the control system to correct hole profile error. The experimental result clearly shows that the measured profile of hole in drilling process by this measuring system and the measured profile by roundness measuring instrument after processing correspond. The usefulness of this corrective control system is verified by the comparison between the dieal profile that must be processed according to the programmed polygonal command and the profile of hole after polygonal control. Further, The experimental result with those systems shows that the roundness can be improved in drilling process.