| 摘要 |
PURPOSE:To perform the boring of a small diameter with high precision by overlapping two throwaway tips and removably fixing them. CONSTITUTION:A throwaway tip 12 consisting of two circular tips is arranged against a drill axis. Accordingly, the balance cut generating a cutting force in axial symmetry is made available. The curvature of the drill is decreased and the boring with high precision can be performed. In addition, the locus of a cutting edge 26 at the center of the drill becomes nearly a conical shape, thereby is centripetal, and also from this standpoint the boremachining of a small diameter can be performed with high precision while using a tip with a comparatively large size. |
