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: A method for controlling the operation of a pressure fluid operated percussion device and to a pressure fluid operated percussion device. The method includes 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 a device for setting the clearance between the transmission piston and the tool.

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: The invention relates to a method for controlling a pressure fluid operated percussion device comprising a working chamber for pressure fluid and in the working chamber a transmission piston installed movably with respect thereto so as to enable a tool installed in the percussion device to be pressed against a material to be broken in order to generate a stress pulse, and to a percussion device. The method comprises adjusting the length of the stress pulse by adjusting the time during which pressure influences the transmission piston. The percussion device comprises an adjustment element and adjustment means for adjusting the influence time of the pressure of the pressure fluid being fed via a control valve and influencing the transmission piston.

Abstract: The invention relates to a method and a rock drilling rig for drilling a hole in a rock. In the method the hole is drilled with a so-called top-hammer rock drilling rig including a drill rod and a cone roller bit at the end of the drill rod. During drilling with the percussion device, stress pulses of low amplitude are produced at a high frequency of at least 200 Hz. In the rock drilling rig, the cone roller bit (3) at the end of the drill rod and the percussion device are configured to feed stress pulses of low amplitude, at the frequency of at least 200 Hz, via the drill rod and the cone roller bit to the rock.

Abstract: A method and software product for controlling a percussion device belonging to a rock-drilling machine, and a percussion device. The impact frequency of the percussion device is set so that the percussion device forms a new compression stress wave to the tool always when reflected waves from the previous compression stress waves reach a first end of the tool. This requires that the impact frequency be set proportional to the propagation time of the stress wave, whereby the length of the used tool and the propagation velocity of the stress wave in the tool material are to be noted.

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 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: The invention relates to a control valve, a percussion device and a method of controlling a working cycle of a percussion device. The percussion device (1) used for breaking rock comprises an impact element (8), which is controlled by a control valve (2). The control valve comprises a control element (5), which is arranged to control channels (7b) leading to a working pressure surface (9) of the impact element (8). The movement of the control element to its extreme position is arranged to form a closed pressure space, where pressure medium compresses and converts kinetic energy of the control element into pressure energy. The pressure energy is re-converted into kinetic energy and utilized when the control element changes its direction.

Abstract: An impact device for a rock drill. The rock drill includes a tool and a mechanism for delivering a stress pulse to the tool. That mechanism includes an impact element supported to a frame of the drill, and a mechanism for subjecting the impact element to stress and thereafter releasing the impact element suddenly from the stress, whereupon stored stress energy in the impact element is discharged in the form of a stress pulse directed at the tool.

Abstract: A rock drilling machine comprising a rotating device (1), a percussion device (2) and a shank (17) where a tool (18) is to be fastened. According to the inventive idea, lubricant used for lubricating the shank is supplied in suitable conduits to pressurize the holes (3a′-3f′) of coupling bolts that join together the different parts of the drilling machine and delivered further in suitable conduits to serve as lubricant on the bearing surfaces between the rock drill and the feed equipment (21).

Abstract: A rock drill includes a mounting frame to which a hammering apparatus and a rotating apparatus is arranged. The mounting frame is made maneuverable with respect to a feeding beam by means of slide blocks fastened to it, whereby a separate carriage is not needed between the drill and the feeding beam. Owing to the mounting frame, the hammering apparatus and/or the rotating apparatus can be replaceable modules. The invention further relates to a mounting frame which is arranged to transmit the feed and recoil forces directed to the drill to feeding means. The mounting frame comprises a section parallel to the feeding beam, to which slide blocks are fastened, and a transverse axial support thereto, to which the hammering apparatus and the rotating apparatus are mounted.

Abstract: A method for adjusting percussion pressure and a drilling machine. In the method the percussion power of a drilling machine is adjusted by moving a shank in the longitudinal direction of the drilling machine forwards when a smaller percussion power is to be transferred from the percussion piston to the shank. The drilling machine comprises at least two groups of pistons moving in the axial direction of the drilling machine, the pistons being connected to act on the shank by means of a pressure medium acting behind the pistons towards the front end of the drilling machine. The drilling machine comprises at least two separate groups of pistons whose travel with respect to one another is different and where pressure medium channels separate from one another lead to the cylinder spaces of both piston groups.