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 of measuring a stress wave and to a measuring device and a rock breaking device. A percussion device (7) gives impact pulses to a waveguide (21), where a compression stress wave and a reflected tensile stress wave are generated, which propagate in the waveguide. The compression stress wave causes an extension in the waveguide and the tensile stress wave a thinning, in which case properties of the waveguide may be determined by measuring geometric changes in the cross section of the waveguide. The measurement data are utilized in controlling the rock breaking device.

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: A pressure-fluid-operated percussion device includes a frame allowing a tool to be arranged movably in its longitudinal direction. Pressure liquid is fed to the percussion device and returned to a pressure liquid tank. A stress pulse is produced in the tool utilizing pressure of the pressure liquid. A pressure liquid source maintains pressure in the working pressure chamber. Pressure liquid is intermittently fed to the percussion device such that the pressure liquid pushes a transmission piston into a predetermined backward position. Pressure liquid is alternately discharged rapidly from the percussion device so that the pressure of the pressure liquid in the working pressure chamber and the pressure liquid flowing from the pressure liquid source pushes the transmission piston towards the tool, generating a stress pulse in the tool.

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: The invention relates to a method of measuring a stress wave and to a measuring device and a rock breaking device. A percussion device (7) gives impact pulses to a waveguide (21), where a compression stress wave and a reflected tensile stress wave are generated, which propagate in the waveguide. The compression stress wave causes an extension in the waveguide and the tensile stress wave a thinning, in which case properties of the waveguide may be determined by measuring geometric changes in the cross section of the waveguide. The measurement data are utilized in controlling the rock breaking device.

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: The invention relates to a coupling arrangement for coupling a drill shank of a rock drill unrotatably but axially movably. The coupling arrangement comprises power transmission members between the surfaces of the drill shank and the rotation bushing, which transmission members rotate along the surfaces, as the drill shank moves longitudinally to the rotation bushing, and transmit the rotation torque from the rotation bushing to the drill shank.

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: 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: 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: 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 percussion device for a rock drilling machine or the like, which includes providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The the stress pulse is provided by way of a stress element of liquid, which is supported to a body of the percussion device. The stress element is subjected to pressure and correspondingly the stress element is released abruptly, whereby the stress energy is discharged as a stress pulse to the tool in direct or indirect contact with the stress element.

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: 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 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: 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.