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: The rock drill apparatus (1) comprises a rock drill machine (6) provided with a percussion device (4), a feed device (9) and a tool (7), the tool (7) end comprising a bit (8) for breaking rock. The tool (7) is arranged to transmit impact energy generated by the percussion device (4) as a compression stress wave to the bit. The feed device (9) is arranged to thrust the tool (7) and the bit (8) against the rock to be drilled, whereby on drilling at least part of the compression stress wave generated by the percussion device (4) to the tool (7) reflects from the rock to be drilled back to the tool (7) as tensile stress, and impact energy of the percussion device (4) is adjusted on the basis of the level of tensile stress (?v) reflecting from the rock.

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. 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: 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: A method and an apparatus for monitoring the operation of a percussion device, which percussion device comprises a percussion piston and a pressure channel for supplying pressure medium to the percussion device for moving the percussion piston. The method and the apparatus measure pressure pulsation of the pressure medium acting in the pressure channel, which pressure pulsation is depicted as a pressure curve. From pressure pulsation are determined parameters depicting the operating state of the percussion device and the operating state of the percussion device is determined on the basis of the parameters. In addition, an arrangement for controlling the operation of the percussion device on the basis of the operating state of the percussion device.

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: 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: A method and an equipment for controlling the operation of a rock drilling apparatus, which rock drilling apparatus comprises a percussion device for producing impact energy to a tool of the rock drilling apparatus, a rotating device for rotating the tool in a drill hole, a feeding device for feeding the tool in the drill hole and a flushing device for supplying flushing agent through the tool and the bit for flushing loose drilling waste from the hole. The feed force and the percussion power are determined and the relation between the feed force and the percussion power is adjusted to a targeted operation area within an upper and a lower limit.

Abstract: A percussion device for a rock drilling machine or the like, which comprises means for providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The means for proving the stress pulse include a stress element (4) of liquid, which is supported to a body (2) of the percussion device and means for subjecting the stress element to pressure and correspondingly for releasing the stress element (4) abruptly, whereby the stress energy is discharged as a stress pulse to the tool in direct or indirect contact with the stress element.

Abstract: The rock drill apparatus (1) comprises a rock drill machine (6) provided with a percussion device (4), a feed device (9) and a tool (7), the tool (7) end comprising a bit (8) for breaking rock. The tool (7) is arranged to transmit impact energy generated by the percussion device (4) as a compression stress wave to the bit. The feed device (9) is arranged to thrust the tool (7) and the bit (8) against the rock to be drilled, whereby on drilling at least part of the compression stress wave generated by the percussion device (4) to the tool (7) reflects from the rock to be drilled back to the tool (7) as tensile stress, and impact energy of the percussion device (4) is adjusted on the basis of the level of tensile stress (&sgr;v) reflecting from the rock.

Abstract: A method and an apparatus for monitoring the operation of a percussion device, which percussion device (1) compiles a percussion piston (3) and a pressure channel (5) for supplying pressure medium to the percussion device (1) for moving the percussion piston (3). The method and the apparatus measure pressure pulsation of the pressure medium acting in the pressure channel (5), which pressure pulsation is depicted as a pressure curve (10). From pressure pulsation are determined parameters depicting the operating state of the percussion device (1) and the operating state of the percussion device (1) is determined on the basis of said parameters. In addition, an arrangement for controlling the operation of the percussion device on the basis of the operating state of the percussion device (1).

Abstract: An impact device for a rock drill or the like, comprising means for delivering a stroke, or a stress pulse, at a tool connected to the impact device. The means for delivering a stress pulse comprise an impact element (2) supported to a frame (1a) of the impact device, and means for subjecting the impact element to stress and correspondingly for releasing the impact element (2) suddenly from stress, whereupon the stress energy is discharged in the form of a stress pulse directed at the tool (3) that is directly or indirectly connected to the impact element.