Abstract: The invention relates to a method for controlling the operation of a pressure fluid operated percussion device and to a pressure fluid operated percussion device. The method comprises influencing the shape of a stress wave by setting a suitable clearance between a transmission piston and a tool. The percussion device is provided with means for setting the clearance between the transmission piston and the tool.

Abstract: A method of generating a stress pulse, and an impact device. In the method, pressure fluid is fed as pressure pulses to a working chamber residing between the frame of the impact device and a tool such that the resulting force presses the tool towards the material to be processed. The impact device comprises a working chamber and device for conveying pressure fluid as pressure pulses thereto such that a force is produced between the frame of the impact device and a tool to press the tool towards the material to be processed.

Abstract: The invention relates to a method for breaking rock to be drilled in rock drilling, in which method the rock to be drilled is subjected to successive stress pulses via a tool. The method comprises stress pulses being exerted on the rock at a high frequency, and the load proportion calculated on the basis of the values of the frequency and the length (tp) of the stress wave being at least 0.075.

Abstract: An impact device includes a frame to which a tool is connectible, and a stress element that is supported on the frame and disposed between the frame and the tool. A hydraulic control system leads pressurized hydraulic fluid into and out of a hydraulic fluid space such that the stress element causes a stress pulse in the tool. The hydraulic control system includes a rotatingly installed control valve that has control openings for intermittently leading the hydraulic fluid out from the hydraulic fluid space.

Abstract: The invention relates to a A pressure-fluid-operated percussion device comprising a frame (2) allowing a tool (13) to be arranged therein movably in its longitudinal direction, means for feeding pressure liquid to the percussion device (1) and for returning pressure liquid to a pressure liquid tank, and means for producing a stress pulse in the tool by utilizing pressure of the pressure liquid.

Abstract: The invention relates to a control valve, a percussion device and a method of controlling a working cycle of a percussion device. A percussion device (1) for breaking rock includes an impact element (8) controlled by a control valve (2). The control valve includes a control element (5) arranged to control channels (7b) leading to a working pressure surface (9) of the impact element (8). The control element, during a working cycle of the control valve, is arranged to open and close pressure channels at several connecting moments so that during one working cycle of the valve, several impact pulses are arranged to be produced.

Abstract: A method of generating a stress pulse, and an impact device. In the method, pressure fluid is fed as pressure pulses to a working chamber residing between the frame of the impact device and a tool such that the resulting force presses the tool towards the material to be processed. The impact device comprises a working chamber and means for conveying pressure fluid as pressure pulses thereto such that a force is produced between the frame of the impact device and a tool to press the tool towards the material to be processed.

Abstract: The invention relates to a control valve, a percussion device and a method of controlling a working cycle of a percussion device. A percussion device (1) for breaking rock includes an impact element (8) controlled by a control valve (2). The control valve includes a control element (5) arranged to control channels (7b) leading to a working pressure surface (9) of the impact element (8). The control element, during a working cycle of the control valve, is arranged to open and close pressure channels at several connecting moments so that during one working cycle of the valve, several impact pulses are arranged to be produced.

Abstract: A pressure fluid operated impact device comprising a frame (2) whereto a tool (3) is mountable movably in its longitudinal direction, and control means (7) for controlling pressure fluid feed to the impact device (1), as well as a method of generating a stress pulse in a pressure fluid operated impact device. The impact device (1) comprises a working chamber (8) and a transmission piston (9) moving therein. Energy charging means for charging energy of pressure fluid and the control means are coupled to allow periodically alternately pressure fluid to flow to the working chamber (8) and, correspondingly, to discharge pressure fluid from the working chamber (8). In the method, pressure fluid is fed to the working chamber (8), which produces a force pushing the transmission piston (9) in the direction of the tool (3), thus generating a stress pulse in the tool (3).

Abstract: The invention relates to an impact device comprising a frame to which a tool is connectible, and between the frame and the tool a stress element (3) supported to the frame of the impact device, and a hydraulic fluid space (6) and means for leading pressurized hydraulic fluid into and out of the hydraulic fluid space (6), respectively. The impact device comprises a rotatingly installed control valve (5) having control channels (5b) for leading the hydraulic fluid intermittently from the hydraulic fluid space (6) to the return channel.

Abstract: In the arrangement, a feed beam made of an aluminum profile comprises a slide guide frame, whereby the outer surface of the slide guide frame and respectively, the inner surface of the slide guide are shaped and dimensioned in such a manner that when the slide guide is on the slide guide frame, they are tight against one another. The other edge of the slide guide flame and respectively, the corresponding edge of the slide guide are shaped in such a manner that when the slide guide is mounted in place, its edge is shape-locked relative to the slide guide frame. The slide guide is also secured by separate securing mechanism to the feed beam in such a manner that it cannot move either in the cross or longitudinal direction relative to the feed beam.

Abstract: An arrangement in a boom for a rock drilling unit, comprising a boom (1), pivotally connected to a frame (2) about a shaft (3), a lift cylinder (4) between the boom (1) and the frame (2), at the other end of the boom a feed beam pivotally connected about a shaft, parallel to the shaft (3), and a swing cylinder (10) between the feed beam and the boom. In the arrangement the lift cylinder (4) comprises three cylinder spaces, of which the first and second cylinder space (13a, 13b) may be connected to a hydraulic fluid supply for lifting or lowering the boom. The third cylinder space (13c) is inside a hollow piston rod (4b) and the cylinder comprises a fixed servo piston (4c) extending inside the piston rod. The third cylinder space (13c) is connected to the swing cylinder (10), to its first cylinder space (18a) and the second cylinder space (18b) of the swing cylinder (10) is connectable to a hydraulic fluid supply or receiver simultaneously with the first cylinder space (13a) of the lift cylinder.