| 摘要 |
<p>A drilling device (1) operates as a down-the-hole drill by a feeding motion along its longitudinal direction (s), a to-and-from hammering motion (t) and a rotational motion (w) around its longitudinal axis (s). The drilling apparatus includes hammering means (8), arranged functional by pressure medium in liquid form led by a second flow arrangement (9) from the pressure medium system of the drilling apparatus. The hammering means (8) include a hollow frame part (7), a valve and flow directing arrangement (o) controlling the flow of pressure medium taking place at the same, a piston arrangement (10) carrying out the said hammering motion by influence of the above and an accumulator arrangement (11) for storing pressure medium. To minimize the cross section of the hammering means (8), a flow way of the second flow arrangement (9) in connection with the piston arrangement (10), such as an input flow way (9a) and/or an output flow way (9b), is divided in two or more flow parts.</p> |
