Patent ID: 9033065
Filing Date: 2015-05-19
Classification: E21B

Abstract:
1. A method for controlling rock drilling wherein a pressure liquid operated percussion device belonging to a rock drill machine delivers stress waves to rock through a tool, wherein the rock drill machine and the tool are simultaneously pushed against the rock by means of a feed motor, and the tool is simultaneously rotated by means of a rotation motor, the method comprising: determining a maximum feed force; supplying pressure liquid to the feed motor along a feed pressure channel and away from the feed motor along a feed return channel; supplying pressure liquid to the percussion device along a percussion pressure channel and away from the percussion device along a percussion return channel; supplying pressure liquid to the rotation motor along a rotation motor pressure channel and away from the rotation motor along a rotation motor return channel; controlling the feed force in relation to a feed speed so that when the feed speed is increased the feed force is decreased and vice versa; controlling the feed force in relation to a rotation torque so that when the rotation torque is increased the feed force is decreased and vice versa; measuring the feed speed; measuring a rotation pressure; controlling the feed force in relation to the measured feed speed and the measured rotation pressure; and controlling a percussion power in relation to the feed force so that when the feed force is decreased below a predetermined value the percussion power is decreased and when the feed force again increases the percussion power is correspondingly increased.