Rock drilling rig and method of driving compressor

Abstract

A rock drilling rig and a method of driving a compressor, wherein the rock drilling rig is operated by a combustion engine and is provided with a flushing system including a compressor for producing pressurized air. The compressor is driven by an electric drive motor. The combustion engine is connected to drive a generator, which produces electric energy that is stored in an energy storage. The stored electric energy can be utilized in driving the compressor.

Description

BACKGROUND OF THE INVENTION

The invention relates to a rock drilling rig, and particularly to an arrangement for driving a compressor of the rock drilling rig.

The invention further relates to a method of driving a compressor of a rock drilling rig.

The field of the invention is defined more specifically in the preambles of the independent claims.

In mines and other work sites rock drilling rigs are used for drilling bore holes to rock surfaces. Typically the rock drilling rig comprises an internal combustion engine for producing needed energy. Further, the rock drilling rig is provided with a boom and a drilling unit in the boom. During a drilling procedure drilling cuttings are formed in the bore hole. The drilling cuttings are flushed away from the bore hole by means of flushing medium. Typically pressurized air is used for flushing. Thus, the rock drilling rig includes a compressor for producing the needed flushing air. It has been noted that a flushing system causes significant loading to the combustion engine.

BRIEF DESCRIPTION OF THE INVENTION

An object of the invention is to provide a novel and improved rock drilling rig provided with a compressor arrangement and a method of driving a compressor.

The rock drilling rig according to the invention is characterized in that the at least one compressor of the flushing system is driven by means of at least one electric compressor drive motor connected to the electric system.

The method according to the invention is characterized by driving the compressor by means of an electric compressor drive motor mechanically independently of the combustion engine.

An idea of the disclosed solution is that a combustion-engine-operated rock drilling rig is provided with a compressed air system comprising one or more compressors. The compressor is driven by one or more electric motors. Kinetic energy produced in the combustion engine is not transmitted to the compressor.

An advantage of the disclosed solution is that the compressor can be driven mechanically and physically independently of the combustion engine of the rock drilling rig. The compressor can be driven accurately and according to the need for pressurized air. This way, unnecessary production of compressed air can be avoided and fuel consumption of a combustion engine can be decreased.

According to an embodiment, electric energy is charged in one or more electric energy storages and the stored electric energy is utilized in driving the electric motor of the compressor. Thanks to the use of stored electrical energy, loading and fuel consumption of a combustion engine can be decreased. The energy storage makes it possible to balance the loading of the combustion engine, whereby a combustion engine with lower power capacity can be used.

According to an embodiment, the electric compressor drive motor is driven only by means of electric energy received from the energy storage.

According to an embodiment, the electric compressor drive motor is driven by means of electric energy received from the energy storage and the generator driven by the combustion engine. The use of the energy storage decreases loadings of the generator and the combustion engine.

According to an embodiment, output capacity of the combustion engine is dimensioned by taking into account the lower power need due to the electric drive of the compressor and electric power taken from the electric storage. The combustion engine may then be dimensioned to have lower power capacity, whereby the engine may be smaller in size and less expensive.

According to an embodiment, the electric energy storage is a battery or a battery package including several batteries.

According to an embodiment, the combustion engine is a diesel engine.

According to an embodiment, the rock drilling rig comprises a control unit for controlling the operation of a flushing system. The control unit monitors the drilling unit and detects the need for pressurized air. Based on the monitoring, the control unit is configured to automatically adjust the running speed of the compressor. This way, the production of pressurized air, i.e. pressure and flow, is adjusted according to the drilling process and consumption of pressurized air.

According to an embodiment, the rock drilling rig comprises a control unit for controlling the operation of the flushing system. The control unit monitors a tramming unit and detects if a carrier is transfer-driven. Based on the monitoring, the control unit is configured to automatically switch off the electrical compressor drive motor for duration of the detected transfer drive. In this way, unnecessary production of pressurized air during the transfer drive is avoided.

According to an embodiment, the operator switches off the electric compressor drive motor for the duration of a transfer drive of the rock drilling rig. Further, the compressor can be stopped for the duration of any other interruptions in the drilling procedure and situations when there is no need for pressurized air. In this way, unnecessary production of pressurized air is avoided and energy is saved.

According to an embodiment, the electric system comprises at least one control device for controlling rotation of the electric compressor drive motor. The drive of the compressor drive motor can be controlled steplessly. The control device for controlling running of the electric motor can be a frequency converter, such as an inverter or a DC/AC converter. Thanks to this embodiment, the output capacity of the compressor can be adjusted in a versatile and effective way, and further, the control is accurate too. Alternatively, the drive of the compressor drive motor can be controlled in predetermined steps or ramps.

According to an embodiment, the tramming unit comprises one or more electric tramming drive motors connected to the electric system and generating power for the transport drive. Electric energy stored in one or more electric energy storage can be utilized in either entirely or partly when running the tramming motor. Thanks to the use of stored electrical energy, loading and fuel consumption of a combustion engine can be decreased.

According to an embodiment, the rock drilling machine is electrically operated and connected to the electrical system. Electrical energy stored in one or more electrical energy storage can be utilized either entirely or partly when running the rock drilling machine. Thanks to the use of stored electrical energy, loading and fuel consumption of a combustion engine can be decreased.

According to an embodiment, the rock drilling rig comprises at least one auxiliary unit which is electrically operated. The auxiliary unit may be a hydraulic unit, for example. The hydraulic unit may produce needed hydraulic pressure for hydraulic cylinders of a boom and other hydraulic auxiliary actuators. The hydraulic unit comprises a hydraulic pump which is electrically driven and connected to the electric system. Electric energy stored in one or more electric energy storages can be utilized either entirely or partly when running the hydraulic pump. Thanks to the use of stored electric energy, loading and fuel consumption of a combustion engine can be decreased.

According to an embodiment, the rock drilling rig comprises a control unit which is configured to determine the drilling efficiency during a drilling process. The control unit may control an electric system to increase storage of electric energy to an energy storage when drilling is performed under maximum efficiency. Thus, when a drilling unit needs less power and the combustion engine has free capacity, more electric energy can be generated by a generator and then stored in the energy storage. Possible extra capacity can be used for charging batteries.

According to an embodiment, the rock drilling rig comprises a control unit which is configured to determine current loading of a combustion engine. The control unit may control an electric system to increase consumption of electric energy stored in an energy storage proportionally to the detected increase in load of the combustion engine. In this way, electric energy of the batteries are used more and more for driving different electric drive motors connected to the electric system in situations when the combustion engine is heavily loaded. This embodiment balances the loading of the combustion engine.

According to an embodiment, the disclosed solution is utilized in top hammer drilling. The drilling unit comprises a top hammer type percussion device which is located at the opposite end of a drilling tool relative to the drill bit.

According to an embodiment, the disclosed solution is utilized in down-the-hole (DTH) drilling. The drilling unit comprises a down-the hole type percussion device which is located at the same end of the drilling tool as the drill bit.

According to an embodiment, the disclosed solution is utilized in rotary drilling. The drilling unit is without any percussion device but, instead, a drilling tool is rotated by means of a rotating device.

According to an embodiment, the disclosed compressor arrangement and procedure are intended for a surface drilling rig which is designed for above ground drilling in opencast mines and other working sites, such as in road, construction and other contracting work sites.

According to an embodiment, the disclosed control procedures are carried out by executing one or more software or computer programs designed for the purpose. The computer program comprises program code means configured to execute the disclosed actions and steps when run on a computer.

Above disclosed embodiments can be combined in order to form suitable solutions provided with necessary features.

BRIEF DESCRIPTION OF THE FIGURES

Some embodiments are described in more detail in the accompanying drawings, in which

FIG. 1 is a schematic side view showing a rock drilling rig for surface working sites,

FIG. 2 is a schematic view showing a principle of down-the-hole drilling,

FIG. 3 is a schematic side view showing a rock drilling rig for underground working sites,

FIG. 4 illustrates a control block diagram of a control system of a rock drilling rig, and

FIG. 5 is a simplified chart showing an electric system of a rock drilling rig.

For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

FIG. 1 shows a feasible rock drilling rig 1 comprising a movable carrier 2 which is provided with one or more booms 3 equipped with a drilling unit DR. The drilling unit DR may comprise a feed beam 5 provided with a rock drilling machine 7 that can be moved on the feed beam 5 by means of a feed device 6. The rock drilling machine 7 may comprise a percussion device for generating impact pulses on a tool 8, and a rotating device for rotating the tool 8. Further, the rig 1 may include a flushing system FS comprising one or more compressors CO for producing compressed air which may be conveyed through a flushing channel 9 to the drilling machine 7 and through the tool 8 to a bore hole 10.

Further, the rock drilling rig 1 may comprise a hydraulic system, which includes a hydraulic pump HP, hydraulic channels, a tank and necessary control means, such as valves and the like. Further, one or more hydraulic actuators may be connected to the hydraulic system.

The rock drilling rig 1 also comprises one or more control units CU arranged to control the systems of the rock drilling rig 1. The control unit CU may be a computer or a corresponding control device comprising a processor, a programmable logic or any other control device suitable for the purpose, to which it is possible to set at least one control strategy, according to which the control unit carries out controlling independently or in cooperation with the operator.

At a drilling site, one or more boreholes are drilled with the drilling unit DR. After the drilling operation, the rig 1 is moved to the next drilling site or position. The rock drilling rig 1 is provided with drive equipment which includes transmission 11 for conveying rotational movement to moving members 12, such as chain tracks or wheels. On the carrier 2, there is also a combustion engine DI, which may be a diesel engine. The combustion engine DI serves as a power unit for producing needed kinetic energy. The kinetic energy can be transmitted via the transmission 11 to the moving members 12 and further to one or more generators for producing needed electrical energy. Electric energy can be stored in one or more energy storages BAT, such as a battery or a battery package. The compressor CO and the hydraulic pump HP can be controlled according to the principles described in this patent application. Further, the needed kinetic power for transport drive can be formed by means of one or more electric tramming drive motors which may also be controlled as disclosed above.

FIG. 2 illustrates a basic principle of a drilling unit DR for down-the-hole DTH drilling, which differs from the top-hammer-drilling shown in FIG. 1 in such way that a percussion device 13 is arranged at an opposite end of a tool 8 as compared to a rotating device 14 of the drilling machine 7. It is also possible that the drilling machine does not include any percussion device, whereby it is called rotary drilling. The above-disclosed flushing system and control principles can be applied to DTH and rotary drilling too.

FIG. 3 discloses a rock drilling rig 1 suitable for underground drilling when tunnels and rock cavities are excavated, and also when ore is mined. Principles and embodiments disclosed above apply also to this type of rock drilling.

FIG. 4 shows a control system 15 comprising one or more control units CU and input means 16 for feeding control data and commands to the control unit CU. The input means may include a control device 17, such as a joy-stick, and an input device 18, such as a keypad, by means of which an operator 19 may communicate with the control unit CU. Further, the control unit CU may read data from one or more memory units 20 and also store data therein. The control unit CU may be provided with one or more control strategies 21 including operating principles and guidelines for controlling the flushing system FS and possibly also other electric systems of the rock drilling rig, such as the traction system and auxiliary systems. The control strategy 21 may include an algorithm for automatically controlling the electric compressor drive motor CM. Control data and parameters may be stored in the memory unit or media 20. Monitoring information and measuring data may be gathered by means of sensors or measuring devices from the systems and actuators connected to the electric system. Also the operation of the combustion engine DI can be monitored. Monitoring or sensing data can be transmitted to the control unit CU. The control unit CU may be a computer equipped with an appropriate processor capable of running a software program including a control algorithm and also processing measuring data for producing control information. On the basis of the measuring data, manual control commands and the control strategy, the control unit CU produces control commands for the disclosed system and allows the disclosed control according to the above presented principles.

In FIG. 5 it is shown a simplified chart of an electric system ES of a rock drilling rig. The combustion engine DI drives the generator GEN and electric energy is produced. By means of the generated electric energy, the electric system of the drilling rig is driven. The drilling unit DR, the tramming unit TR and the auxiliary unit, such as the hydraulic system HS, can be driven by the energy produced by the generator GEN. Further, the generated energy can be used to charge the energy storage BAT. There may be a voltage transformer between the generator and the energy storage. The flushing system FS can be driven by means of the energy stored in the energy storage BAT. Alternatively electric energy can be directed to the flushing system FS from two sources, namely from the energy storage BAT and the generator GEN.

The flushing system FS may further include a control device CD, which may comprise a frequency converter, by which the rotation of the electric compressor drive motor CM can be controlled steplessly. The operation of the control device CM may be controlled by a control unit CU.

The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.

Claims

1. A rock drilling rig comprising:

a movable carrier;

a tramming unit for performing transfer drive of the carrier;

at least one drilling boom movable relative to the carrier and provided with a drilling unit including a rock drilling machine;

a flushing system having at least one compressor for producing pressurized air utilized in flushing a drill hole during drilling;

a combustion engine for producing kinetic energy;

at least one generator arranged to be driven by the combustion engine and arranged to produce electric energy to an electric system; and

at least one energy storage connected to the electric system, wherein the rock drilling rig is combustion engine operated, needed electric energy of the rock drilling rig is produced by the at least one generator; and the at least one compressor of the flushing system is driven by means of at least one electric compressor drive motor connected to the electric system.

2. A rock drilling rig as claimed in claim 1, wherein the at least one electric compressor drive motor is driven by means of electric energy received from the at least one energy storage.

3. A rock drilling rig as claimed in claim 1, wherein the at least one electric compressor drive motor is driven by means of electric energy received from the at least one energy storage and the at least one generator.

4. A rock drilling rig as claimed in claim 1, wherein the rock drilling rig includes at least one control unit for controlling the operation of the flushing system; the control unit is arranged to monitor the drilling unit; and the control unit is arranged to adjust the running speed of the compressor and the production of pressurized air according to the drilling process.

5. A rock drilling rig as claimed in claim 1, wherein the rock drilling rig includes at least one control unit for controlling the operation of the flushing system; the control unit is arranged to monitor the tramming unit and to detect transfer drive of the carrier; and the control unit is arranged to switch off the electric compressor drive motor for the duration of the transfer drive.

6. A rock drilling rig as claimed in claim 1, wherein the electric system includes at least one control device for controlling rotation of the electric compressor drive motor.

7. A rock drilling rig as claimed in claim 1, wherein the tramming unit includes at least one electric tramming drive motor connected to the electric system and generating power for the transport drive.

8. A rock drilling rig as claimed in claim 1, wherein the rock drilling machine is electrically operated and connected to the electric system.

9. A rock drilling rig as claimed in claim 1, wherein the rock drilling rig includes a hydraulic system and hydraulic actuators connected to the hydraulic system; the hydraulic system (HS) includes at least one hydraulic pump for generating hydraulic pressure; and the hydraulic pump is electrically driven and connected to the electric system.

10. A method of driving a compressor of a rock drilling rig which is provided with a combustion engine, the method comprising the steps of:

driving a compressor by means of a motor;

conducting produced pressurized air to a flushing system;

producing the needed electric energy for an electric system of the rock drilling rig by at least one generator driven by the combustion engine; and

driving the compressor by means of an electric compressor drive motor mechanically independently of the combustion engine.

11. A method as claimed in claim 10, wherein the electric compressor drive motor is driven by utilizing electric energy stored in at least one energy storage.

12. A method as claimed in claim 10, wherein the production of pressurized air is adjusted according to the drilling process.

13. A method as claimed in claim 10, further comprising determining drilling efficiency during a drilling process; and increasing storage of electric energy to at least one energy storage when drilling is performed under maximum efficiency.

14. A method as claimed in claim 10, further comprising determining current loading of the combustion engine; and increasing consumption of electric energy stored in at least one energy storage proportionally to the detected increase in the load of the combustion engine.

15. A method as claimed in claim 10, further comprising determining the current use of compressed air;

and switching off the electric compressor drive motor when com-pressed air is not used.