| 摘要 |
Method of rock drilling with a percussion rock drilling machine (2) to which a drill string (18) comprising parts (31, 32, 33, 19) screwed together is connected. In order to obtain efficient loosening of the screw joints and reduced drilling time the feed force is reduced at a predetermined distance (37) from a predetermined hole bottom (36) at the same time as the drill string (18) is exerted to impacts with substantially unchanged strength until the drill hole has been completed. |
