| 摘要 |
The tubular drill has cutters (2, 3, 4) as a cutting set which are arranged on a support body (1). The width (b) of the cutting faces (2a, 3a, 4a) of the cutters (2, 3, 4) increases in the opposite direction to the direction of rotation (D). In addition, the cutters (3, 4) arranged in the opposite direction to the direction of rotation (D) are set back from the respective cutter (2, 3) in front of them by the height (h) measured parallel to the axis of the tubular drill. The aforesaid dimensioning of the cutting faces (2a, 3a, 4a), with conventional contact pressures, leads to each cutter (2, 3, 4) penetrating sufficiently deeply into the material to be machined so that abrasive wear leading to premature failure of the tubular drill does not occur. <IMAGE> |
