| 摘要 |
<p>A method for adjusting percussion pressure and a drilling machine. In the method the percussion power of a drilling machine is adjusted by moving a shank (2) in the longitudinal direction of the drilling machine forwards when a smaller percussion power is to be transferred from the percussion piston to the shank (2). The drilling machine comprises at least two groups of pistons (4a, 4b) moving in the axial direction of the drilling machine, the pistons being connected to act on the shank (2) by means of a pressure medium acting behind the pistons towards the front end of the drilling machine. The drilling machine comprises at least two separate groups of pistons (4a, 4b) whose travel with respect to one another is different and where pressure medium channels (7a, 7b) separate from one another lead to the cylinder spaces of both piston groups.</p> |
