METHOD OF AND DEVICE FOR ADJUSTING THE FEED MOVEMENT OF A DRILL ROD FOR DRILLING A ROCK

摘要

In a method of and device for adjusting the feed movement of a drill rod for drilling a rock, the drill rod is rotated by a pressure-medium-operated rotary motor and fed in a drilling direction and in the opposite direction by a pressure-medium-operated feed motor. A pressure change on the pressure side of the rotary motor due to a change in the rotation resistance on the rotary motor acts oppositely on the pressure and outlet sides of the feed motor toward reversing the feed force of the feed motor, i.e. in inverse and direct dependence on the pressure change, respectively. The pressures on the pressure side and the outlet side of the feed motor are, therefore, controlled so that, when the pressure on one side increases because of the pressure change, the pressure on the other side decreases and vice versa.