Abstract: The invention relates to a rock drilling apparatus comprising a carrier and at least one drill boom mounted in the carrier and provided with a drifter and a feeding beam. Valves for the control of the operations of the drifter and the feeding beam are arranged in the form of an integral control unit. The control unit is mounted in a cradle provided for the feeding beam and it communicates with the carrier by means of merely two pressure fluid hoses and a control cable.

Abstract: The invention relates to a method and an arrangement for adjusting the percussion and the feed of a rock drilling apparatus with respect to each other. In the method, the volume flow of pressure fluid to be supplied to a percussion device (7) and a feed motor (8) is adjusted on the basis of the feed pressure of the feed motor (11), a volume flow adjusted pump (1) being controlled so that the ratio of the pressure applied to the persussion device (7) to the pressure of the feed motor (11) is set by control valves (10, 14). In the arrangement, pressure fluid is supplied to the percussion device (7) and the feed motor (11) by means of a volume flow adjusted pump (1). The arrangement further comprises control valves (10, 14) by means of which the volume flow of the pressure fluid fed by the pump (1) is kept such that the ratio of the pressure of the percussion device and that of the feed motor (11) remains substantially constant.