Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B7/00—Special methods or apparatus for drilling
  • E21B7/02—Drilling rigs characterised by means for land transport with their own drive, e.g. skid mounting or wheel mounting
  • E21B7/022—Control of the drilling operation; Hydraulic or pneumatic means for activation or operation
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B44/00—Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
  • E21B44/02—Automatic control of the tool feed
  • E21B44/06—Automatic control of the tool feed in response to the flow or pressure of the motive fluid of the drive
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
  • E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure

Definitions

• the invention relates to a method for controlling the operation of a rock drilling rig, which rock drilling rig comprises a feeding apparatus for feeding a tool in a hole to be drilled, a rotating apparatus for rotating a tool in the hole to be drilled, and means for feeding flushing medium into the hole to be drilled to remove from the hole to be drilled the drill cuttings generated in the hole during the drilling, the method comprising setting the set value of the feeding pressure of the feeding apparatus on the basis of the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus.
• Rock drilling rigs and rock drill machines arranged in them are used for drilling and quarrying rock, for example in underground mines, open pit mines and excavation work sites.
• there are typically four different functions in use simultaneously i.e. rotating the drill bar in the hole to be drilled, striking rock with a percussion device at a drill bit via a drill shank and drill rods that are extensions to the drill shank, as well as feeding the drill forwards in the hole to be drilled, and flushing with which drilling waste, i.e. drill cuttings, is removed from the hole to be drilled.
• drilling waste i.e. drill cuttings
• DTH Down-The-Hole
• the percussion piston is positioned in a drill hole, at the bottom of the hole, and strikes directly at the drill bit instead of the drill shank. Breaking of rock therefore takes place mainly by the effect of the percussion, and the purpose of the rotating is mainly to ensure that the buttons of the bit or other working parts of the drill bit at the outer end of the drill rods always strike rock at a new point. By means of the feed, the contact between the drill bit and the rock is kept sufficient.
• torque adjustment drilling In connection with controlling rock drilling rigs, what is called torque adjustment drilling may be used in which the intention is to keep the rotating torque, i.e. the rotating pressure, of a rotating apparatus of a rock drill machine of a rock drilling rig at its set value by means of the feed force, i.e. the feeding pressure, of the feeding apparatus of the rock drill machine.
• the momentary current value of the rotating pressure of the rotating apparatus is subtracted from the set value of the rotating pressure of the rotating apparatus, which gives the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus.
• the control and adjustment unit sets the set value for the control and adjustment unit of the feed device, on the basis of which value the control and adjustment unit of the feed device adjusts the feeding pressure.
• An object of this invention is to achieve a new type of solution for controlling the operation of torque adjustment drilling of a rock drilling rig.
• the method according to the invention is characterized by determining the difference variable between the set value and the current value of the volume flow of the flushing medium and by affecting the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus of the rock drilling rig on the basis of the difference variable between the set value and the current value of the volume flow of the flushing medium.
• the rock drilling rig is characterized in that the rock drilling rig further comprises means for determining the difference variable between the set value and the current value of the volume flow of the flushing medium, and at least one control unit for controlling the operation of the rock drilling rig by affecting the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus of the rock drilling rig on the basis of the difference variable of the set value and the current value of the volume flow of the flushing medium.
• the operation of the rock drilling rig which comprises a feeding apparatus for feeding a tool in a hole to be drilled, a rotating apparatus for rotating a tool in the hole to be drilled and means for feeding flushing medium into the hole to be drilled to remove from the hole to be drilled the drill cuttings generated in the hole during the drilling and in which the set value of the feeding pressure of the feeding apparatus is set on the basis of the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus, can be controlled by determining the difference variable between the set value and the current value of the volume flow of the flushing medium and by affecting the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus of the rock drilling rig on the basis of the difference variable between the set value and the current value of the volume flow of the flushing medium.
• the amplification coefficient of the difference variable between the set value and the current value of the volume flow of the flushing medium enables determination of the weight value with which the difference variable between the set value and the current value of the volume flow of the flushing medium affects the difference variable between the set value and the current value of the rotating pressure of the rotating apparatus in each drilling situation.
• Figure 2 shows schematically a principled view of different functions of the rock drilling rig
• Figure 3 shows schematically an arrangement for controlling the operation of the rock drilling rig.
• FIG. 1 shows schematically the structure of a rock drilling rig 1.
• the rock drilling rig 1 comprises a movable carrier 2, which is provided with a boom 3, at the free end of which a feeding beam 4 is arranged. Further, the feeding beam 4 is provided with a rock drill machine 5, which can be moved relative to the feeding beam 4.
• the rock drilling rig 1 and the devices connected to it are operated by means of the power generated by an engine 6 arranged on the carrier 2, whereby the rock drilling rig 1 is a unit moving and functioning independently.
• the engine 6 is typically an combustion engine, such as a diesel engine.
• Figures 2 and 3 show schematically an embodiment implementing the solution.
• Figure 2 shows schematically, at a general level, arrangement of different functions of the rock drilling rig 1 without the percussion apparatus and parts belonging to it.
• Figure 3 shows schematically a control arrangement based on torque adjustment.
• Figure 2 illustrates a flow measuring arrangement 12 arranged in connection with the flush line 9 of the rock drilling rig 1 for measuring the volume flow FLOW of the flushing medium flowing in the flush channel system, i.e. in practice the current value FLOWMEA S of the volume flow of the flushing medium, in other words in the case of the rock drilling rig 1 shown in Figure 1 , for measuring the volume flow of compressed air.
• the flow measuring arrangement 12 can also be positioned at a point other than the flush line 9 in the flush channel system.
• the measuring arrangement 12 of the volume flow FLOW of the flushing medium may comprise, for example, a measuring device based on a Venturi tube and measuring the residual pressure difference of the Venturi tube in a manner known as such.
• the flow measuring arrangement 12 can be, however, implemented in very many different ways as far as the volume flow FLOW of the flushing medium flowing in the flow channel system or variables comparable with it can be measured in some way.
• the difference between the pressures measured at any two different points in the flush channel system may be used for measuring the amount of flow of the flushing medium.
• the rock drilling rig 1 further comprises a pressure measuring arrangement 18, for example a pressure sensor, for determining the current value P_ROTMEAS of the rotating pressure p_ROT of the rotating apparatus 16.
• the pressure measuring arrangement 18 is positioned in a pressure medium channel 20 of the rotating device 16 between the rotating apparatus 16 and the directional control valve 21 , which pressure medium channel 20 comes from a rotating pump 19 and conveys pressure medium to the rotating device 16.
• the set value p_FEEDs ⁇ of the feeding pressure of the feeding apparatus 17 is raised, and vice versa.
• the measurement of the current value FL0W ME AS of the volume flow of the flushing medium can be connected to the adjustment of torque adjustment drilling in such a way that the difference variable between the set value FLOWSET and the current vallue FLOWMEA S of the volume flow of the flushing medium, determined with a calculating member 30, affects the difference variable ⁇ p_ROT between the set value P_ROTSET and the current value P_ROTMEAS of the rotating pressure.
• the variables are converted in a manner obvious as such to a person skilled in the art in such a way that they can be processed together, whereby information corresponding to the variables can be processed for example by subtracting them from each other.
• the difference variable ⁇ FLOW between the set value FLOWSET and the current value FLOWMEA S of the volume flow of the flushing medium or the variables individually may naturally be subtracted from the difference variable ⁇ p_ROT between the set value P_ROTSET and the current value P_ROT M EAS of the rotating pressure.
• a control and adjustment unit 26 of the rotating apparatus 16 gives a control and adjustment unit 27 of the feeding apparatus 17 a control command CTRL for decreasing the feeding pressure p-FEED.
• the control and adjustment unit 26 of the rotating apparatus 16 thus decreases the set value P_FEEDSET of the feeding pressure p_FEED, as a result of which the control and adjustment unit 27 of the feeding apparatus 17 decreases the feeding pressure p_FEED.
• the feeding pressure p_FEED can be decreased for example by controlling the adjustment value of the pressure regulating valve 22 of the feeding apparatus.
• Figure 2 further shows schematically a feeding pump 23 and a pressure medium channel 24 of the feeding apparatus 17 feeding pressure medium to the feeding apparatus 17, as well as a directional control valve 25 of the feeding apparatus 17.
• Figure 3 thus shows for both the rotating apparatus 16 and the feeding apparatus 17 separate control and adjustment units 26 and 27, respectively, but these control and adjustment units 26 and 27 may naturally be a part integrated into the control unit 13 of the whole rock drilling rig 1 , as may also calculating means 28 and 30, and an amplification element 29 shown in Figure 3.
• the control unit 13 transmits, in a manner shown schematically in Figure 2, a control variable CTRL to the pressure regulating valve 22 of the feeding apparatus 17 to decrease the feeding pressure p_FEED.
• the difference variable ⁇ FLOW between the set value FLOWSET and the current value FLOWMEAS of the volume flow of the flushing medium can be conveyed through a particular amplification element 29, in which amplification or an amplification coefficient K is determined, by means of which the effect of the difference variable ⁇ FLOW of the set value and the current value of the volume flow FLOW of the flushing medium on the difference variable ⁇ p_ROT between the set value and the current value of the rotating pressure p_ROT can be changed.
• the coefficient K can be set to be zero in cases where it is not desirable that the flush flow affects the adjustment.
• One such case may be, for example, escaping of the flush flow in fragmented rock, which pould, without management of exceptional cases of the type described above, lead to an undue increase in the feeding pressure, for instance.
• the amplification coefficient K can, if required, be used for converting the unit of the difference variable ⁇ FLOW between the set value FLOW S ET and the current value FLOWMEAS of the volume flow of the flushing medium such that it is subtractable from the set value P_ROT S ET of the rotating pressure.
• the rock drilling rig 1 may thus comprise one or more control units, whereby one control unit may control the operation of the whole rock drilling rig, or whereby there may be a separate control unit for each part of the drilling.
• the control unit may be, for example, a device comprising a microprocessor and/or signal processor and possibly some memory capacity external to them, the device carrying out the required calculation and comparison steps by means of its software.
• the control unit may also be a device comprising only different electronic circuits, having members required for generating the difference between two or more variables, for example for generating the difference variable ⁇ p_ROT of the rotating pressure determined on the basis of the set value p_ROTs ⁇ of the rotating pressure, the real momentary value, i.e.
• control unit may thus comprise the calculating member 28 as well as the calculating member 30 for generating the difference variable ⁇ FLOW of the set value and the current value of the volume flow of the flushing medium.
• the general structure and operating principle of control units and devices of this type are known as such to a person skilled in the art.
• the solution is shown in connection with a rock drilling rig in which compressed air is used as the flushing medium, this compressed air being produced by means of the compressor 7 or another device applicable to producing compressed air.
• the solution can, however, be correspondingly utilized in rock drilling rigs in which the flushing medium is hydraulic fluid, which may be for instance water, a mixture of water and air or a mixture of a chemical.
• the compressor When hydraulic fluid is used as the flushing medium, the compressor is replaced with a pump or another corresponding device which, by means of the power generated directly or indirectly by the engine 6, feeds flush fluid along the flush channel system to the rock drill machine 5 and further to through the tool 10 of the rock drill machine 5 to the drill hole 8, whereby the drill cuttings detached from the rock are pushed out of the drill hole 8 by means of the flush fluid.
• a special container or connection for supplying flush fluid to the rock drilling rig is thus to be added to the rock drilling rig.
• the changes caused to the apparatus when the air used as the flushing medium is replaced with fluid are obvious as such to a person skilled in the art.
• features presented in this application can be used as such, irrespective of other features.
• features presented in this application can, if required, be combined to produce various combinations.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
• Earth Drilling (AREA)

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• 2006
  • 2006-06-01 FI FI20065369A patent/FI118778B/fi not_active IP Right Cessation
• 2007
  • 2007-05-30 EP EP07730797A patent/EP2021580A1/de not_active Withdrawn
  • 2007-05-30 WO PCT/FI2007/050310 patent/WO2007138170A1/en active Application Filing

Non-Patent Citations (1)

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