| 摘要 |
<p>The construction of cutting edges of a drilling tool includes air outlet openings (4) projecting from the hollow attachment part of the drill body against the forwards projecting cutting edges (5,5a). The outlet openings (4) are so positioned that the discharged air is directed against the cutting edges (5,5a) surface in the direction of rotation. It thus cools the cutting edges (5,5a) and removes the drilled material. The air outlet openings (4) are terminating at the base of the cutting edges (5,5a) in the direction of the drill rotation. The axis of the air discharged through the openings is parallel to the side surface of the cutting edges (5,5a) a and crosses the surface. They are fitted with a throttle which reduces the diameter of the outlet openings (5,5a).</p> |
