Cooling configuration, rock drilling rig, and cooling method

Abstract

A cooling arrangement, an excavation vehicle, and a method for cooling in an excavation vehicle are provided. The excavation vehicle (MV) comprises a combustion engine (E) for performing driving, a hydraulic system (HS) for powering at least one hydraulic actuator (HA), and an electrically operable power pack (PP) for powering the hydraulic system. The cooling arrangement (CA) comprises a first liquid cooling circuit (8) for cooling the combustion engine and a second liquid cooling circuit (10) for cooling the hydraulic fluid. The second liquid cooling circuit is selectively connectable to the first liquid cooling circuit when the combustion engine is switched off.

Description

Background Art

[0001] The present invention relates to a cooling arrangement for an excavation vehicle.

[0002] The present invention further relates to a rock drill rig and a cooling method in an excavation vehicle.

[0003] The field of the present invention is more specifically defined in the preamble of the independent claims.

[0004] In mines and other work sites, different types of excavation vehicles are used. The excavation vehicle may include a diesel engine for generating the power required to drive the excavation vehicle between the work site and the target location, and an electrically operable power package for performing the actual work at the work site. The electric power package is arranged to provide power to a hydraulic system and a hydraulic excavation actuator connected to the hydraulic system. The hydraulic oil of the hydraulic system can be overheated if it is not properly cooled during operation. Therefore, various cooling arrangements and oil coolers for cooling the hydraulic oil of the hydraulic system have been disclosed. However, the known solutions have shown some drawbacks.

Summary of the Invention

[0005] The object of the present invention is to provide a new and improved cooling arrangement and method. A further object is to provide a rock drill rig provided with a new and improved cooling system.

[0006] The cooling arrangement according to the present invention is characterized by the characteristic features of the first independent device claim.

[0007] The rock drill rig according to the present invention is characterized by the characteristic features of the second independent device claim.

[0008] The method according to the present invention is characterized by the characteristic features of the independent method claim.

[0009] The concept of the disclosed solution is that the first liquid cooling circuit of the combustion engine of an excavation vehicle is utilized to cool a second liquid cooling circuit which aims to cool the hydraulic fluid of the hydraulic system. Further, the disclosed solution is a cooling arrangement for an excavation vehicle, which vehicle comprises a combustion engine for performing driving, a hydraulic system for powering at least one hydraulic actuator, and an electrically operable power pack for powering the hydraulic system. The first liquid cooling circuit for cooling the combustion engine comprises at least one first radiator provided with a fan and a first pump unit for circulating a coolant between the combustion engine and the first radiator. Since the second liquid cooling circuit is selectively connectable to the first liquid cooling circuit, the same coolant, the same first radiator, and the same fan are implemented in both liquid cooling circuits. The second liquid cooling circuit further comprises an oil cooler which is a liquid-to-liquid cooler for converting the heat of the hydraulic oil into the coolant of the liquid cooling circuit. The coolant circulates in the second liquid cooling circuit only when the combustion engine is not operating. In other words, the hydraulic oil of the hydraulic system is cooled by a second liquid cooling circuit which is connectable to the first liquid cooling circuit of the combustion engine in a situation where the combustion engine is not operating and cooling is not required. Thus, the two closed liquid cooling systems are selectively connectable.

[0010] The advantage of the disclosed solution is that an effective cooling circuit for the combustion engine is available when there is no need to cool the combustion engine. In this way, effective cooling of the hydraulic oil is achieved and the hydraulic system can be driven with high power and for a long operating period without the risk of overheating of the hydraulic oil.

[0011] A further advantage is that the second cooling circuit for cooling the hydraulic oil can be relatively simple and inexpensive. The connection of the first cooling circuit to the combustion engine also makes the arrangement and control simple.

[0012] Furthermore, the disclosed solution uses a large radiator sized to cool the combustion engine, and when the engine is off, this large cooling area of the radiator is available only for cooling the second liquid cooling circuit. Thus, the hydraulic oil can be effectively cooled.

[0013] According to one embodiment, the coolant or cooling liquid is an aqueous liquid. The coolant can be a mixture of glycol and water. The glycol may be ethylene glycol.

[0014] According to one embodiment, the cooling arrangement comprises only one radiator. The entire radiator and the cooling area of the radiator are shared by the first liquid cooling circuit and the second liquid cooling circuit.

[0015] According to one embodiment, the second liquid cooling circuit can be directly connected to the radiator of the first liquid cooling circuit. In other words, the radiator has ports for both circuits.

[0016] According to one embodiment, the second liquid cooling circuit can be connected to the flow path of the first liquid cooling circuit by a tube element or a hose element. In this solution, the second liquid cooling circuit is not directly connected to the radiator.

[0017] According to one embodiment, the cooling arrangement may comprise a second radiator associated with the first radiator. The hydraulic oil cooled by an oil / coolant exchanger, i.e., an oil cooler, is carried to the second radiator for further cooling. The second radiator is cooled by the fan of the first radiator. Thus, two-stage hydraulic oil cooling is achieved.

[0018] According to one embodiment, the cooling arrangement may comprise a third radiator associated with the first radiator. The third radiator is an air intake cooler for cooling the air supplied to the combustion engine.

[0019] According to one embodiment, the cooling arrangement may comprise a fourth radiator associated with the first radiator. The fourth radiator is an oil cooler for cooling the hydraulic fluid of the hydrostatic transmission during travel. During travel, the temperature of the hydraulic fluid rises and needs to be cooled. When the mining vehicle is not moving and the combustion engine is off, the fan of the first radiator operates to cool the second liquid cooling circuit, and thereby the fan also cools the fourth radiator. Thus, the hydraulic fluid of the hydrostatic transmission can also be cooled during a series of rock drilling or other mining operation cycles when the mining vehicle is not moving.

[0020] Furthermore, it may be possible to implement a second liquid cooling circuit for cooling the hydraulic fluid of the transmission in substantially the same way as cooling a basic hydraulic system intended to operate a hydraulic mining work actuator.

[0021] According to one embodiment, the cooling arrangement may comprise a fifth radiator associated with the first radiator. The third radiator is, for example, an oil cooler for cooling the motor oil of the combustion engine.

[0022] According to one embodiment, the cooling arrangement may comprise several radiators cooled by the same fan. This type of radiator configuration may be referred to by the name "combination cooler".

[0023] According to one embodiment, the cooling arrangement comprises only one oil cooling device for cooling the hydraulic fluid. Thus, an oil / air exchanger or a further oil / water heat exchanger is not required by the disclosed effective second liquid cooling circuit.

[0024] According to one embodiment, at least one hydraulic actuator connected to the hydraulic system is a hydraulic mining actuator such as a hydraulic rock drill or a rock bolt device.

[0025] According to one embodiment, the second liquid cooling circuit may be connected to cool only one oil cooler, or two or more oil coolers may be connected to the second liquid cooling circuit.

[0026] According to one embodiment, the cooling arrangement comprises at least one control unit for automatic control of the second liquid cooling circuit. Detection data for indicating the operating state of the combustion engine is provided to the control unit. Further, the control unit controls the on and off of the second cooling mode in response to the detection data to control the second cooling circuit. In other words, the second liquid cooling circuit is automatically controlled under a predetermined or input control strategy.

[0027] According to one embodiment, the second liquid cooling circuit can be cooled when one or more hydraulic actuators of the hydraulic system operate and the temperature of the hydraulic fluid rises. The temperature of the hydraulic oil can be monitored by one or more temperature sensors. The monitoring data is transmitted to the control unit, and the second liquid cooling circuit can be cooled when necessary.

[0028] According to one embodiment, the control system of the second liquid cooling circuit includes an input control strategy for cooling the second liquid cooling circuit even in a situation where the hydraulic oil is circulating in the hydraulic system even if the hydraulic actuator connected to the hydraulic system is not active. The control unit may switch the hydraulic pump on to circulate the hydraulic oil in the system. In this way, the cooling system can extend the cooling time for cooling the working fluid. Furthermore, the cooling efficiency is improved. This is a kind of all-time cooling utilized when the combustion engine is off.

[0029] According to one embodiment, the hydraulic pump may alternatively continue to operate during operation even if the hydraulic actuator connected to the hydraulic system is not active. Furthermore, the control unit is configured to switch the circulation pump unit on and off to circulate the coolant in the second liquid cooling circuit according to the principles disclosed herein.

[0030] According to one embodiment, the second liquid cooling circuit can be pre-cooled before the operation of the hydraulic actuator. When the temperature of the hydraulic oil is set to a low level, the hydraulic system will be able to withstand heavy loads during subsequent work cycles. The control unit may control the cooling of the second liquid cooling circuit in all suitable situations where the combustion engine is not operating. The control unit may be provided with data regarding subsequent work cycles and operations, whereby the control unit can estimate or calculate the required pre-cooling amount based on that data.

[0031] According to one embodiment, the second liquid cooling circuit is alternatively manually controllable by an operator of the mining vehicle.

[0032] According to one embodiment, the second liquid cooling circuit comprises at least one control valve for opening and closing the circulation of the second liquid cooling circuit to the radiator. In other words, the circulation in the second liquid cooling circuit can be completely stopped by the control valve when the combustion engine is cooled. This is advantageous because the temperature of the coolant after the operation of the combustion engine can be approximately 100 °C, which is significantly higher compared to the normal operating temperature of the hydraulic oil (less than 75 °C). Furthermore, the hot coolant cannot affect the temperature of the hydraulic oil.

[0033] According to one embodiment, there is one control valve. In an alternative solution, there are two control valves for controlling the circulation. The control valve may also be referred to as an isolation valve.

[0034] According to one embodiment, one or more control valves are electrically operable valves and are controlled under the control of the control unit described above.

[0035] According to one embodiment, one or more control valves are on-off valves.

[0036] According to one embodiment, the actuator of the second liquid cooling circuit can be controlled using either on-off control or proportional control. Proportional control enables the regulation of the flow in the circuit. The controllable actuators can be valves and pumps.

[0037] According to one embodiment, the second liquid cooling circuit may not have any control valves for opening and closing the circulation of the second liquid cooling circuit to the radiator. Instead, there may be a circulation pump whose operation is configured to serve as a circulation prevention element when stopped. Thus, the circulation pump can be liquid-tight when not operating. In other words, the circulation pump can serve the roles of both a pump device and a valve element. Furthermore, the number of components in the system can be reduced.

[0038] According to one embodiment, the fan of the first radiator is equipped with a dedicated fan motor and can operate independently in relation to the operation of the combustion engine. In other words, the fan is not mechanically coupled to the combustion engine, and thereby the operation of the fan does not depend on the operation of the combustion engine.

[0039] According to one embodiment, the fan motor is a hydraulic motor connected to a hydraulic system.

[0040] According to one embodiment, the fan motor is an electric motor.

[0041] According to one embodiment, the fan motor is controlled under the control of a control unit.

[0042] According to one embodiment, the second liquid cooling circuit includes at least one dedicated circulation pump for circulating the coolant in the second liquid cooling circuit. In other words, the second liquid cooling circuit has its own pump, and thereby the circulation of the coolant is independent of the pump of the first liquid cooling circuit. A further advantage of this solution is that the flow rate can be adjusted by the circulation pump unit, and thereby the cooling capacity can be generally adjusted.

[0043] According to one embodiment, the circulation pump unit includes an electric motor and a pump. The electric motor is controllable under the control of a control unit.

[0044] According to one embodiment, the motor of the circulation pump unit may alternatively be a hydraulic motor.

[0045] According to one embodiment, the first pump unit is arranged to provide a liquid flow to both liquid cooling circuits. Thus, there may be only one pump for circulating the liquid coolant.

[0046] According to one embodiment, at least one oil cooler for cooling the hydraulic fluid of the hydraulic system is a shell and tube type oil cooler. In other words, the oil cooler includes a liquid cooling space between an external shell and several tubes through which the oil flows inside the tubes. The oil cooler is typically a heat exchanger.

[0047] According to one embodiment, other types of hydraulic fluid - coolant exchangers are also available. Thus, the oil cooler may alternatively be, for example, a flat plate heat exchanger.

[0048] According to one embodiment, at least one oil cooler for cooling the hydraulic fluid of the hydraulic system is a heat exchanger. Using the oil cooler, it is also possible to transfer heat from the liquid coolant to the hydraulic fluid, thereby heating the hydraulic system when it is operating in cold conditions. This possibility enables preheating of the hydraulic system.

[0049] According to one embodiment, the disclosed solution relates to a rock drilling rig comprising a mobile carrier, a combustion engine and a transmission system for driving the rock drilling rig, a drilling boom attached to the carrier and provided with a hydraulic rock drill, a hydraulic system for powering at least the hydraulic actuator of the rock drill, an electrically operable power pack for powering at least the hydraulic system, and a cooling arrangement for cooling the working fluid of the combustion engine and the hydraulic system. The cooling arrangement comprises a second liquid cooling circuit for cooling the working fluid and connectable to a first liquid cooling system of the combustion engine, whereby the cooling arrangement is configured to alternately cool the combustion engine or the hydraulic system. The cooling arrangement is according to the features and embodiments disclosed herein.

[0050] According to one embodiment, the disclosed solution relates to a method for cooling in an excavation vehicle. The method includes cooling a combustion engine of the excavation vehicle by a first liquid cooling circuit and cooling a working fluid of a hydraulic system of the excavation vehicle by at least one oil cooler. The method further includes connecting at least one oil cooler to a second liquid cooling circuit and selectively connecting the second liquid cooling circuit to the first liquid cooling circuit in a situation where the combustion engine does not require cooling, whereby the cooling surface area of a radiator of the first liquid cooling circuit is utilized to cool the working fluid.

[0051] According to one embodiment, the method further includes regulating a flow rate of a coolant in the second liquid cooling circuit by a dedicated circulation pump unit of the second liquid cooling circuit.

[0052] According to one embodiment, the method further includes preventing circulation of the coolant in the second liquid cooling circuit when the combustion engine is operating.

[0053] According to one embodiment, the method further includes pre-cooling the working fluid before starting operation of at least one hydraulic actuator of the hydraulic system.

[0054] According to one embodiment, the method further includes using a common radiator and a common fan to perform cooling of the combustion engine and the oil cooler.

[0055] According to one embodiment, the method further includes operating a common fan for the first liquid cooling circuit and the second liquid cooling circuit independently of the operation of the combustion engine.

[0056] According to one embodiment, the second cooling mode is selectable when the combustion engine is not operating and there is no need for cooling. When the second cooling mode is selected to be on, the control unit can start the actual cooling measures in the circuit by controlling the actuator of the second liquid cooling circuit. The cooling measures in the second cooling circuit can be triggered, for example, by coolant temperature data, temperature data regarding the hydraulic oil, or both. However, other sensing data and control data, as well as control principles, are also available for performing the trigger. Data regarding the state of the hydraulic circuit, i.e., whether the hydraulic circuit is on or off, may be provided to the control unit. In other words, the cooling in the second liquid cooling circuit does not start automatically when the combustion engine stops, and dedicated control steps are required.

[0057] The embodiments disclosed above may be combined to form suitable solutions having the required ones of the above features.

[0058] Some embodiments are described in more detail in the accompanying drawings.

Brief Description of the Drawings

[0059]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0060] For clarity, the figures show simplified examples of some embodiments of the disclosed solutions. In the figures, like reference numerals identify like elements.

[0061] FIG. 1 discloses a rock drilling rig 1 comprising a movable carrier 2. The rock drilling rig 1 is an example of an excavation vehicle MV. One or more drilling booms 3 are attached to the carrier 2. Each of the booms 3 may comprise a drilling unit 4 provided with a hydraulic rock drill 5. There is a hydraulic system HS for powering the hydraulic actuators HA of the rock drill 5, such as a hydraulic impact device and a hydraulic rotary device. There may also be other hydraulic actuators, such as a supply device and a boom cylinder, connected to the hydraulic system HS. The combustion engine E and the transmission system T are arranged on the carrier 2 used for the travel of the rock drilling rig 1 between work sites to other locations. The transmission system T may comprise a mechanical gear system and transmission elements, or alternatively, may comprise hydrostatic transmission elements. The combustion engine E operates only when the rig 1 is in motion and is switched off when the excavation operation is being carried out. Thus, the carrier 2 comprises an electrically operable power pack PP for at least powering the hydraulic system HS and providing hydraulic power to the hydraulic actuators.

[0062] Furthermore, the hydraulic oil of the combustion engine E and the hydraulic system HS is cooled by a cooling arrangement based on the circulation of a closed coolant. For the sake of simplicity, FIG. 1 discloses only some features of the cooling arrangement. There is a radiator 6 and a fan 7 for cooling the coolant. FIG. 1 also discloses some fluid passages or tubes for circulating the coolant between the radiator 6 and the combustion engine E. The cooling arrangement is controllable by one or more control units CU. The cooling arrangement is according to the features and embodiments disclosed herein.

[0063] FIG. 2 discloses some features of the cooling arrangement CA. The cooling arrangement CA comprises a first liquid cooling circuit 8 that cools the combustion engine E and includes at least one first radiator 6 with a fan 7. A first pump unit 9 is arranged to circulate the coolant between the combustion engine E and the first radiator 6. The cooling arrangement CA also comprises a second liquid cooling circuit 10 that is selectively connectable to the first liquid cooling circuit 8, whereby the same coolant, the first radiator 6, and the fan 7 are implemented in both liquid cooling circuits 8, 10. The second liquid cooling circuit 10 comprises one or more dedicated circulation pump units 11 for circulating the coolant in the second liquid cooling circuit 10. The second liquid cooling circuit 10 may also comprise means for interrupting the circulation when the combustion engine is operating. There is also one or more oil coolers 12 for cooling the hydraulic oil of the hydraulic system. The oil cooler is a liquid-to-liquid cooler 13 connected to the second liquid cooling circuit 10, whereby the heat of the hydraulic oil is transferred to the coolant via the oil cooler 13. The cooling arrangement CA comprises one or more control units CU for the automatic control of the second liquid cooling circuit 10. The control unit CU comprises a processor 14 for executing control measures under control strategies, programs, and algorithms 15 input into the control unit CU. Input data, sensing data, and control data 16 may also be input into the control unit CU. The input data may comprise, for example, sensing data indicating the operating state of the combustion engine.

[0064] Figure 3 discloses a cooling arrangement CA comprising a first liquid cooling circuit 8 for cooling the combustion engine E. A first pump unit 9 circulates coolant between the combustion engine E and the first radiator 6 when the combustion engine E is operating. This situation is shown in Figure 3. The circulation of the same coolant in the second liquid cooling circuit 10 is prevented by control valves 17a and 17b, which may be electrically operable valves controlled by a control unit CU. The fluid flow in the second liquid cooling circuit 10 is formed by a dedicated circulation pump unit 11 or a second pump unit comprising a pump 18 and a motor M. The motor M may be an electrically operable motor and may be controlled by the control unit CU. In Figure 3, the control valves 17a, 17b are closed and the circulation pump unit 11 is not operating, whereby the coolant flows only in the first liquid cooling circuit 8.

[0065] The control unit CU may receive detection data indicating the operating state of the combustion engine from a sensor S. In Figure 3, in response to detecting that the combustion engine E is operating, the control unit CU executes a first cooling mode for circulating coolant in the first liquid cooling circuit 8.

[0066] Other detection data such as temperature data regarding the combustion engine and the liquid coolant may also be provided to the control unit CU.

[0067] The control unit CU may also control the motor 19 of the fan 7 to adjust the cooling capacity of the first radiator 6.

[0068] Figure 3 further discloses a hydraulic system HS connected to an oil cooler 12 for cooling the hydraulic fluid of the hydraulic system HS. The pressure and flow in the hydraulic system HS are generated by a hydraulic pump 20 driven by an electric motor M. The motor M is powered by a battery B. Alternatively, it may be connected to an external power source. Thus, there is a power supply power pack PP for operating the hydraulic system HS independently of the combustion engine E. A mining actuator such as a rock drill 5 is connected to the hydraulic system HS. The hydraulic fluid is heated in the rock drill 5 and is thereby carried to the tank 21 via the oil cooler 12.

[0069] Figure 4 is the same as Figure 3, but discloses a cooling arrangement CA in a situation where the combustion engine E is stopped and there is no need for cooling. Furthermore, the second liquid cooling circuit 10 is activated by a control unit CU by opening the control valves 17a, 17b and operating a dedicated circulation pump unit 11. The fan 7 cools the coolant in the radiator 6, and the cooled coolant such as a water mixture flows to the oil cooler 12 or the exchanger.

[0070] Figures 3 and 4 disclose that the combustion engine E is provided with a thermostat TH that is normally closed and, when opened after the temperature of the coolant rises to the set temperature, allows the cooled coolant to pass through the passages in the combustion engine E. When the combustion engine E is not operating, the temperature of the coolant is below the set temperature and the thermostat TH is closed. In other words, the thermostat TH prevents the flow through the combustion engine E when the second liquid cooling circuit 10 is operating. However, it is possible to use any other flow control valve or element that selectively shuts off the flow in the engine E.

[0071] Figure 5 discloses an alternative cooling arrangement CA that differs from that disclosed in FIGS. 3 and 4 in that the second liquid cooling circuit 10 includes only one control valve 17b. Further, the control valve 17b is hydraulically controlled, whereas in FIGS. 3 and 4, the control valve is an electric valve. Another difference is related to the first radiator 6 and there is a second radiator 22 that is cooled by the same fan 7. The hydraulic oil returning from a hydraulic actuator such as the rock drill 5 is first cooled by the oil cooler 12 and then conveyed through the passage 23 to the second radiator 22 which is an oil air-cooled radiator. Thereafter, the hydraulic oil is conveyed to the tank 21 through the passage 24. One or more filters may be provided between the second radiator 22 and the tank 21. In this embodiment, there is a two-stage oil cooling arrangement.

[0072] Furthermore, it is possible to direct a part of the hydraulic fluid flow that only passes through the oil cooler 12 and a part of the flow that only passes through the radiator 22. Thus, for example, the return hydraulic fluid flow of the impact device of the rock drill 5 can be directed to the oil cooler 12, and the return flow of the rotary device of the rock drill 5 can be directed to the radiator 22.

[0073] Figure 6 discloses yet another embodiment of the cooling arrangement CA. In this solution, the second liquid cooling circuit 10 does not have a control valve. Instead, the pump 19 can act as a flow blocking element when not operating. Further, the pump 18 is rotated by a hydraulic motor. Another difference from the previously disclosed solution is that there are a total of three radiators, namely the first radiator 6 for the coolant and two further radiators 25, 26 that utilize the cooling effect of the common fan 7. The further radiators can be arranged to cool, for example, the air supplied to the engine E, the engine's motor oil, and the hydraulic oil.

[0074] There may be several radiators arranged adjacent to each other in the vertical or horizontal direction. Different hydraulic circuits, or other circuits to be cooled, may be connected to these radiators in different ways according to their cooling requirements. It is also possible to connect two or more radiators together using series or parallel connections between them.

[0075] Figure 6 further discloses that the temperature of the hydraulic fluid can be monitored by the temperature sensor TS. Detection data from the temperature sensor, and among other possible sensors, the sensor S for monitoring the operating state of the combustion engine E may be supplied to the control unit CU for the required control data provided.

[0076] In Figure 6, the electric power package PP is connected to the power transmission grid PG instead of or in addition to the on-board battery.

[0077] Figure 6 further discloses a sensor S2 for detecting characteristics of the coolant, such as temperature.

[0078] The control unit CU can control the second liquid cooling circuit 10 based on the temperature detection data of the coolant and the hydraulic oil, that is, based on the data received from the temperature sensor TS or the temperature sensor S3, or both sensors TS and S3. The control unit CU can control the actuators and devices of the second liquid cooling circuit 10 based on the detection data, and the control may be either on-off or proportional type control. Data regarding whether the hydraulic system HS is operating may also be provided to the control unit CU.

[0079] Figure 7 discloses a solution that is different from the previous solution in that in the cooling arrangement CA there is only one pump for circulating the coolant in both the liquid cooling circuits 8, 10. Thus, the first pump unit 9 may be driven independently of the combustion engine E. The flow generated by the first pump unit 9 can be controlled by valve elements V1, V2 connected to the liquid cooling circuits 8, 10 in order to control the flow in one circuit at a time. Alternatively, the flow may be controlled by one valve element V3 which may be, for example, a 3 / 2 or 4 / 2 direction control valve. The valve elements V1 and V2 may be, for example, on-off control valves. Figure 7 discloses a situation in which the second liquid cooling circuit 10 is operating.

[0080] The drawings and the related description are only intended to illustrate the concept of the invention. The invention may vary in its details within the scope of the claims.

Claims

1. A mining vehicle (MV) comprising a combustion engine (E) for performing propulsion, a hydraulic system (HS) for supplying power to at least one hydraulic actuator (HA), an electrically operated power pack (PP) for supplying power to the hydraulic system (HS), and a cooling arrangement (CA), The aforementioned cooling arrangement (CA) is A first liquid cooling circuit (8) for cooling the combustion engine (E), comprising at least one first radiator (6) provided with a fan (7), and a first pump unit (9) for circulating a coolant between the combustion engine (E) and the first radiator (6), At least one oil cooler (12) for cooling the hydraulic fluid of the hydraulic system (HS) and In a mining vehicle (MV) equipped with, The cooling arrangement (CA) includes a second liquid cooling circuit (10) that can be selectively connected to the first liquid cooling circuit (8), thereby enabling both liquid cooling circuits (8, 10) to be equipped with the same coolant, the first radiator (6), and the fan (7). The oil cooler (12) is a liquid-to-liquid cooler connected to the second liquid cooling circuit (10), thereby transferring the heat of the hydraulic fluid to the coolant via the oil cooler (12). The cooling arrangement (CA) further comprises a first cooling mode for circulating the coolant in the first liquid cooling circuit (8) in response to detection that the combustion engine (E) is operating, and a second cooling mode for circulating the coolant in the second liquid cooling circuit (10) only in response to detection that the combustion engine (E) is not operating. A mining vehicle (MV) characterized by the following features.

2. The cooling arrangement (CA) includes at least one control unit (CU) for automatic control of the second liquid cooling circuit (10), The control unit (CU) is provided with detection data indicating the operating status of the combustion engine (E). The control unit (CU) is configured to control the second liquid cooling circuit (10) by controlling the on and off of the second cooling mode in response to the detected data. The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

3. The second liquid cooling circuit (10) includes at least one control valve (17a, 17b, V1, V2, V3) for opening and closing the circulation of the second liquid cooling circuit (10) to the radiator (6). The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

4. The fan (7) of the first radiator (6) is equipped with a dedicated fan motor (19) and is capable of operating independently in relation to the operation of the combustion engine (E). The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

5. The second liquid cooling circuit (10) includes at least one dedicated circulation pump unit (9) for circulating the coolant in the second liquid cooling circuit (10). The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

6. The first pump unit (9) is configured to circulate the coolant in the second liquid cooling circuit (10) as well. The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

7. The cooling arrangement (CA) includes at least one of the following temperature sensors for providing temperature detection data to the control unit (CU): a temperature sensor (S3) for detecting the temperature of the coolant and a temperature sensor (TS) for detecting the temperature of the hydraulic fluid. The control unit (CU) is configured to control the second liquid cooling circuit (10) in the second cooling mode in response to the received temperature detection data. The mining vehicle (MV) according to claim 1, characterized in that it is a mining vehicle (MV) as described in claim 1.

8. A rock drilling rig (1), Movable carrier (2), A combustion engine (E) and a transmission system (T) for driving the rock drilling rig (1) The drilling boom (3) is attached to the carrier (2) and includes a drilling unit (4) equipped with a hydraulic rock drill (5), A hydraulic system (HS) for supplying power to at least the hydraulic actuator (HA) of the rock drill (5), At least an electrically operated power pack (PP) for supplying power to the hydraulic system (HS), The combustion engine (E) and the cooling arrangement (CA) for cooling the hydraulic fluid of the hydraulic system (HS) Equipped with, The cooling arrangement (CA) includes a second liquid cooling circuit (10) that cools the hydraulic fluid and is connectable to a first liquid cooling system (8) of the combustion engine (E), thereby configuring the cooling arrangement to alternately cool the combustion engine (E) or the hydraulic system (HS). The cooling arrangement (CA) is according to any one of claims 1 to 7. A rock drilling rig (1) characterized by the following features.

9. A method for cooling a mining vehicle (MV), The combustion engine (E) of the mining vehicle (MV) is cooled by a first liquid cooling circuit (8) comprising at least one first radiator (6) equipped with a fan (7) and a first pump unit, Cooling the hydraulic fluid of the hydraulic system (HS) of the mining vehicle (MV) by at least one oil cooler (12), wherein the oil cooler is a liquid-to-liquid cooler, and cooling the hydraulic fluid Includes, Connecting the at least one oil cooler (12) to the second liquid cooling circuit (10), thereby connecting the at least one oil cooler (12) in both liquid cooling circuits (8, 10), the same coolant, the first radiator (6), and the fan (7) to be mounted therein. In response to the detection that the combustion engine (E) is operating, the coolant is circulated in the first liquid cooling circuit (8), The second liquid cooling circuit (10) is selectively connected to the first liquid cooling circuit (8) only when the combustion engine (E) does not require cooling, thereby utilizing the cooling area of ​​the radiator (6) of the first liquid cooling circuit (8) to cool the hydraulic fluid. A method characterized by the following.

10. The flow rate of the coolant in the second liquid cooling circuit (10) is adjusted by a dedicated circulation pump unit (11) for the second liquid cooling circuit (10). The method according to claim 9, characterized by the above.

11. Pre-cooling the hydraulic fluid before starting operation of at least one hydraulic actuator (HA) of the hydraulic system (HS). The method according to claim 9 or 10, characterized by the above.

12. To operate the common fan (7) of the first liquid cooling circuit and the second liquid cooling circuit (8, 10) independently of the operation of the combustion engine (E). The method according to claim 9 or 10, characterized by the above.

13. To detect the temperature of at least one of the coolant and the hydraulic fluid, The detected temperature is provided to the control unit (CU), and the second liquid cooling circuit (10) is controlled in response to the received temperature data when the combustion engine (E) does not require cooling. The method according to claim 9 or 10, characterized by the above.

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