| 摘要 |
<p>The invention relates to a method for down-the-hole drilling, the drilling being carried out by an apparatus, having a drilling device (1) that comprises a casing part (2) and a drilling unit (3), at a drilling head of which there are at least first drilling means (4) and second drilling means (5), removably coupled with each other, and a flushing flow arrangement (6), and whereby the flushing medium is being brought by first flushing means (6a) of the flushing flow arrangement (6) onto the drilling surface (P) and returned from the drilling surface (P) together with the drilling waste by second flushing means (6b) of the flushing flow arrangement (6) through axially directed (s) and in respect with each other separate feed flow and return flow channels (6a', 6b') between the first and second drilling means (4,5). Return flow of flushing medium together with drilling waste through one or more return flow channels (6b') is made more efficient by introducing flushing medium directly from the first flushing means (6a) by means of an auxiliary flush assembly (6c) at a return flow opening assembly (6b'o) of the return flow channel/channels (6b') essentially on the drilling surface (P). The invention also relates to an apparatus applying the method.</p> |
