| 摘要 |
A spiral drill for machining deep holes with a convex front surface and elements of crushing chips contains two teeth, and two main cutting edges with a symmetrical double-angle and polished core of drill. The main cutting edges and front surface of each tooth is convex, and double-angle is equal &phis;=140°, in addition, each main cutting edge has a depression from the side of periphery of the tooth that has a depth α and a length l, which equals to one-third of the length of main cutting edge, and the depth α depends on the diameter of cutting tool as follows: α = (0,.. 0.15)d, where d – diameter of drill. |
