Method and a means for aligning a rock drill

摘要

The alignment of the drill stem and bit of a rock drill rig is corrected when the force of drilling and the feeding power on the drilling machine of the rig has resulted in a change in the direction of the drill stem because of deformation of the articulated and extensible drill boom of the rig and of its pivotally supported drill support on the drill boom. The drill rig is of the type that includes elements for measuring boom lengths and articulation angles, servos for controlling such lengths and angles and a control unit which is connected to the measuring elements and servos for adjusting the drill stem and bit. The various articulation angles which are required to compensate for deformations of the drill boom and drill support are determined as if the drill boom and support were in an unloaded condition, on the basis of measured values of the boom lengths and articulation angles which have been registered in the control unit in an unloaded condition. The adjusted articulation angles are corrected to the determined articulation angles when full feeding power is applied.