| 摘要 |
<p>A deep hole drilling machine employing an external system for supplying coolant to a drilling portion in which high drilling efficiency can be achieved even if the drilling hole is deep by enhancing the discharge performance of chips from the drilling portion without setting the supply pressure of coolant at a high level. A tubular boring head (2) having discharging openings (4a, 4b) communicating with a chip discharge passage (10) on the edge (3a-3c) side is attached to the distal end of a hollow boring bar (1) having interior serving as the chip discharge passage (10), bypass holes (5,...) are provided at a plurality of circumferential positions in the circumferential wall (21) of the boring head (2) to penetrate obliquely such that the outer opening (5a) is located closer to the distal end side of the head than the inner opening (5b), and a part of coolant supplied externally to the drilling portion side flows through the bypass holes (5,...) into the boring head (2), thus generating attraction force to the discharge side and accelerating discharge of the chips (S).</p> |
