| 摘要 |
In a method for underground drilling, an impact tool (2) advancing in the ground is used to ream a previously formed hole (11), and a medium is supplied to the apparatus to produce the impactive movement of the impact tool (2) and for flushing drill cuttings out of the drilling point. By means of the medium, the drill cuttings are simultaneously carried in the drilling direction along a previously formed hole. The flushing medium intended for removing drill cuttings is introduced to the drilling point along a different channel (1a) than the working medium intended for producing the impactive movement is introduced into the impact tool (2). The flushing medium is a liquid or a flowing mixture, especially a liquid or mixture more viscous than water, such as drilling mud, and at least part of the flushing medium is led back opposite to the supply direction after it has flushed the drilling point. |
