JP6695765B2 - Work machine and cooling control method for work machine - Google Patents

Description

  The present invention relates to a work machine such as a dump truck or a hydraulic excavator equipped with a fan, and a cooling control method for the work machine.

  In a dump truck for mines that repeatedly transports resource raw materials mined in a mine to a predetermined dumping ground, an engine drives a generator, and the electric power generated from the generator is supplied to a motor to drive a rear wheel. A series hybrid type electrically driven dump truck is known as one of the working machines. This kind of dump truck has a large resource transportation capacity of several hundred tons per vehicle, and it is required to increase the operating rate as much as possible. (Hereinafter, referred to as fuel consumption for convenience) is significantly larger than that of passenger cars such as automobiles. Therefore, it is an issue to suppress the fuel consumption amount in terms of energy saving and operation cost.

  The dump truck is provided with a cooling device that circulates a refrigerant through each part of the engine to dissipate the heat received by the refrigerant to the outside in order to prevent excessive temperature rise of the engine. This cooling device is provided with, for example, a pump that circulates cooling water as a refrigerant, a radiator that dissipates the heat stored in the cooling water, and a fan that blows cooling air to the radiator. Further, the cooling device has a circuit in which cooling water flows near the cylinder of the engine and becomes relatively high temperature, and a circuit in which cooling water flows through the supercharger portion of the engine and becomes relatively low temperature. Are separated. A high temperature radiator is connected to the circuit where the cooling water has a relatively high temperature (the former), and a low temperature radiator is connected to the circuit where the cooling water has a relatively low temperature (the latter).

  Both the high-temperature radiator and the low-temperature radiator are housed in a grill box on the front of the dump truck in such a manner as to overlap in the front-rear direction of the vehicle. The fan generates a flow of cooling air, that is, an airflow, which passes through both the high-temperature radiator and the low-temperature radiator from the vehicle rear side of the high-temperature radiator and the low-temperature radiator. Generally, as the amount of air flow generated by the rotation of the fan (air volume) increases, the fan power, and thus the fuel consumption amount of the dump truck, increases.

  Therefore, in order to suppress the fuel consumption of the dump truck, a technique of mounting a plurality of fans on a vehicle and controlling the operation of each fan has been conventionally proposed. Specifically, as one of its prior art, at least one cooling element for cooling the medium and a first configured to continuously generate a forced air flow through at least one region of the cooling element. A situation with a radiator fan and an additional radiator fan, the additional radiator fan being unable to provide sufficient airflow for the first radiator fan to optionally cool the medium in the cooling element. There is disclosed at least one additional radiator fan activated in a vehicle cooling fan arrangement for a vehicle configured to produce an increased air flow through at least one region of a cooling element (eg, US Pat. 1).

  Further, as one of other conventional techniques, a first electric blower for circulating cooling air through a brushless motor to a radiator and a radiator and a first electric blower for circulating cooling air through a brushless motor to a radiator and a radiator. When it is determined that the temperature of the cooling water is lower than the predetermined value based on the detection output from the electric blower of No. 2 and the temperature sensor that detects the temperature of the cooling water, only the first electric blower is operated to cool the cooling water. There is disclosed a vehicle electric fan system including a control device that operates both the first and second electric blowers when it is determined that the temperature is equal to or higher than a predetermined value (see, for example, Patent Document 2).

U.S. Pat. No. 8015954 US Pat. No. 6,986,260

  As described above, in the conventional techniques disclosed in Patent Documents 1 and 2, since the number of operating fans changes according to the condition of the cooling water, it is possible to apply each of these conventional techniques to a work machine such as a dump truck. In this case, the amount of cooling airflow passing through a specific radiator and the area (heat exchange area) of the airflow can be changed, so that the amount of heat exchange between cooling water and cooling air can be adjusted as a result. Seems to.

  However, since the passage of the cooling water in the radiator is unchanged, the area where the cooling airflow generated by the specific fan in the radiator should play a role when the specific fan among the plurality of fans is stopped. The cooling water that passes through flows back without heat exchange with the cooling air. Therefore, in such a situation, the amount of heat exchange between the cooling water and the cooling air with respect to the fan power is not necessarily high.

  In other words, even if each of the above-mentioned conventional techniques is applied to a work machine such as a dump truck, the cooling water passing through the radiator is exchanged with the cooling air generated by the fan over the entire radiator when a specific fan is stopped. It's difficult to get it done. As a result, the fan power for obtaining the desired heat exchange amount between the cooling water and the fan increases, and the fuel consumption of the dump truck cannot be sufficiently suppressed, which is a problem.

  The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to provide a work machine and a cooling control method for the work machine capable of reducing fan power and sufficiently suppressing fuel consumption. Especially.

In order to achieve the above-mentioned object, the working machine of the present invention includes an engine, at least one fan that takes in outside air to generate cooling air, and a first part that flows through a predetermined first part in the engine. A plurality of first heat exchangers that perform heat exchange between the refrigerant and the cooling air, and a plurality of first heat exchangers that are arranged on the upstream side of the airflow of the cooling air with respect to each of the plurality of first heat exchangers and that are provided in a predetermined first position A plurality of second heat exchangers for exchanging heat between the second refrigerant flowing through the two parts and the cooling air, and the plurality of first heat exchangers are connected in parallel to each other , and the first refrigerant is connected to the engine. a first circulation circuit for circulating between the plurality of first heat exchanger, is connected in parallel to the plurality of second heat exchanger, a second heat exchanger the second refrigerant of the plurality and the engine A second circulation circuit that circulates between the first heat exchanger and a second circulation circuit that circulates between the first circulation circuit and the first circulation circuit that communicates with or cuts off the flow paths of the first refrigerant that respectively flow into the first heat exchangers. An on-off valve, a plurality of second on-off valves which are provided in the second circulation circuit and which connect or block the flow paths of the second refrigerant flowing to the plurality of second heat exchangers, respectively, and the at least one fan. At least one of the first refrigerant and the second refrigerant passes through only a region in which the cooling air flow is generated by driving the at least one fan by the fan driving unit. An opening / closing control unit for controlling opening / closing operations of the plurality of first opening / closing valves and the plurality of second opening / closing valves, respectively.

  According to the work machine and the work machine cooling control method of the present invention, fan power can be reduced and fuel consumption can be sufficiently suppressed. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is a general view showing the composition of the dump truck concerning a 1st embodiment of the present invention. FIG. 2 is an overall view showing the configuration of a drive circuit that drives the dump truck shown in FIG. 1. It is a perspective view which shows the structure of the cooling device which cools the engine shown in FIG. It is a schematic diagram for demonstrating the state of heat exchange with the cooling wind and each refrigerant by the cooling device shown in FIG. It is a block diagram which shows the function structure of the control apparatus shown in FIG. It is a figure which shows the relationship between the temperature information of each refrigerant memorize | stored in the control apparatus shown in FIG. 1, and the opening command of a control valve, and the operation command of a fan. It is a schematic diagram for demonstrating the heat exchange condition of the cooling wind and each refrigerant by the cooling device in the case of the line 03 shown in FIG. It is a flow chart which shows a flow of control processing of a cooling device by a control device concerning a 1st embodiment of the present invention. It is a figure which shows the relationship between the control process result of the upstream side radiator and the downstream side radiator with respect to each fan obtained from a series of flow of the control process shown in FIG. It is a figure which shows the relationship of the temperature information of each refrigerant memorize | stored in the control apparatus which concerns on 2nd Embodiment of this invention, and the opening command of a control valve, and the operation command of a fan. It is a schematic diagram for demonstrating the structure of the cooling device which concerns on 3rd Embodiment of this invention. It is a figure which shows the relationship of the temperature information of each refrigerant memorize | stored in the control apparatus which concerns on 3rd Embodiment of this invention, and the opening command of a control valve, and the operation command of a fan. It is a schematic diagram for demonstrating the structure of the cooling device which concerns on 4th Embodiment of this invention. It is a figure which shows the relationship between the temperature information of each refrigerant memorize | stored in the control apparatus which concerns on 4th Embodiment of this invention, and the opening command of a control valve, and the operation command of a fan. It is a schematic diagram for demonstrating the structure of the cooling device which concerns on 5th Embodiment of this invention. It is a figure which shows the relationship of the temperature information of each refrigerant | coolant memorize | stored in the control apparatus which concerns on 5th Embodiment of this invention, and the opening command of a control valve, and the operation command of a fan. It is a front view which shows the structure of the principal part of the cooling device which concerns on 6th Embodiment of this invention. It is a side view which shows the structure of the principal part of the cooling device which concerns on 6th Embodiment of this invention. It is a figure which shows the relationship of the temperature information of each refrigerant | coolant memorize | stored in the control apparatus which concerns on 6th Embodiment of this invention, and the opening command of a control valve, and the operation command of a fan. It is a side view which shows the structure of the principal part of the cooling device which concerns on 7th Embodiment of this invention.

  Hereinafter, an embodiment for carrying out a work machine and a work machine cooling control method according to the present invention will be described with reference to the drawings. In the following description, the front-rear, left-right, and up-down directions are the same as the front-rear, left-right, and up-down directions of the vehicle, unless otherwise specified.

[First Embodiment]
As shown in FIG. 1, a first embodiment of a work machine according to the present invention is composed of a dump truck 1 for loading and carrying earth and sand as an object to be carried at a work site such as a mine. .. The dump truck 1 includes a vehicle body frame 11 and wheels rotatably provided on the vehicle body frame 11. The wheels are, for example, front wheels 12L and 12R (only the left front wheel 12L is shown in FIG. 1) arranged at the left and right ends of the front portion of the body frame 11, respectively, and the rear portion of the body frame 11. Of the rear wheels 13L and 13R (only the left rear wheel 13L is shown in FIG. 1) that are rotatably arranged on each of the left and right ends of the rear wheel.

  The front wheels 12L and 12R are steered wheels that are steered based on a steering angle that is input via steering or the like, and are driven by the rear wheels 13L and 13R that are driven by the rear wheels 13L and 13R via the road surface on which the dump truck 1 travels. It is a driving wheel. On the other hand, the rear wheels 13L and 13R are drive wheels that are driven by converting the driving force of an engine 32 (see FIG. 2) described later into rotational movement. Traveling motors 40L and 40R (see FIG. 2), which will be described later, for driving the rear wheels 13L and 13R, and rotational speeds of the rear wheels 13L and 13R are adjusted on the rotary shafts of the rear wheels 13L and 13R. Reduction gears 41L and 41R (see FIG. 2) described later are attached.

  Further, the dump truck 1 is disposed above the front wheels 12L and 12R, a deck (upper deck) 14 on which an operator can walk, and a rudder 15 mounted on the front surface of the vehicle for the operator to climb to an upper surface 14U of the deck 14. A cab 16 installed on the upper surface 14U of the deck 14 for an operator to ride on; a control cabinet 17 mounted on the front of the vehicle for accommodating various electric power devices; and a drive circuit 31 of the dump truck 1 described later (see FIG. 2) and a plurality of grid boxes 18 for dissipating excess energy as heat.

  Further, the dump truck 1 is arranged on the front side of the vehicle, and is capable of undulating with respect to the grill box 19 for accommodating each device of a cooling device 51 (see FIG. 3) described later for cooling the engine 32 and the body frame 11. It is provided with a loading platform 20 for loading cargo such as earth and sand or ore.

  Although not shown, the control device 71 includes, for example, a CPU (Central Processing Unit) that performs various calculations for controlling the entire operation of the vehicle, and a ROM (Read Only Memory) that stores a program for executing the calculations by the CPU. And a storage device such as a HDD (Hard Disk Drive) and a RAM (Random Access Memory) serving as a work area when the CPU executes a program.

  In such a hardware configuration, a program stored in a recording medium such as a ROM, an HDD, or an optical disk (not shown) is read out to the RAM, and the program (software) and the hardware cooperate by operating under the control of the CPU. A functional block that operates to realize the function of the control device 71 is configured. Details of the functional configuration of the control device 71 that characterizes the first embodiment of the present invention will be described later.

  Next, the configuration of the drive circuit 31 that drives the dump truck 1 according to the first embodiment of the present invention will be described in detail with reference to FIG. A region surrounded by a broken line shown in the drawing represents that it is stored in the control cabinet 17, and a region surrounded by a dashed line represents that it is stored in the grid box 18.

  As shown in FIG. 2, the drive circuit 31 mounted on the dump truck 1 is an engine 32 as a drive source, and a main generator 33 that is mechanically connected to the engine 32 and that generates power by the drive force of the engine 32. And the auxiliary generator 34, and each device electrically connected to the main generator 33 and the auxiliary generator 34 and housed in the control cabinet 17 and the grid box 18.

  The engine 32 is a diesel turbo engine having a supercharger (not shown) that supercharges air supplied to each cylinder (not shown), and includes a main generator 33, an auxiliary generator 34, a hoist cylinder 23, and the like. Drives the hydraulic pump that is the hydraulic source.

  The main generator 33 and the auxiliary generator 34 are connected to the output shaft of the engine 32 and rotate together. The main generator 33 mainly generates three-phase AC power that serves as a power source for the left and right traveling motors 40L and 40R. The auxiliary generator 34 generates three-phase AC power that serves as a power source for auxiliary machines, such as cabinet heaters (not shown).

  The control cabinet 17 includes a traveling system controller (not shown) that monitors and controls the entire traveling system in the dump truck 1, a rectifier 35 and a capacitor 36 that convert the AC voltage generated by the main generator 33 into a direct current, Provided between the left and right main inverters 37L, 37R for controlling the operation of the traveling motors 40L, 40R, the auxiliary inverter 38 for controlling the operation of each auxiliary machine, and the capacitor 36 and the main inverters 37L, 37R. A chopper 39 that takes out necessary electric power from the generator 33 is stored.

  In the grid box 18, a grid resistor 42 electrically connected to the chopper 39, a grid blower 43 for blowing air inside the vehicle to the grid resistor 42, and a grid blower 43 by the electric power supplied from the auxiliary inverter 38. An auxiliary motor 44 for driving the motor, various sensors and switches (not shown) are stored.

  Next, the configuration of the cooling device 51 according to the first embodiment of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 3, the cooling device 51 is arranged in front of four fans 52A to 52D that take in outside air to generate cooling air, and these fans 52A to 52D, and a predetermined first inside the engine 32. One part, for example, a pair of downstream side radiators (first heat exchangers) 53A and 53B for exchanging heat between the engine cooling water (first refrigerant) A flowing through each cylinder side and the cooling air, and each downstream side radiator. 53A and 53B are arranged in front of a predetermined second part in the engine 32, for example, a pair of supercooler cooling water (second refrigerant) B flowing through the supercharger side and heat exchange with the cooling air. The upstream radiators (second heat exchangers) 54A and 54B are provided.

  Further, the cooling device 51 is arranged in front of the upstream radiator 54A, is arranged in front of the brake oil cooler 55 that exchanges heat between the brake oil C and the cooling air, and in front of the upstream radiator 54B, and cools the air conditioner refrigerant D. A first circulation circuit, which is connected in parallel to each of the downstream radiators 53A and 53B for exchanging heat with the wind and in which the engine cooling water A circulates between the engine 32 and each of the downstream radiators 53A and 53B. 57 and a second circulation circuit 58 that is connected in parallel to each of the upstream radiators 54A and 54B and circulates the supercharger cooling water B between the engine 32 and each of the upstream radiators 54A and 54B. The engine 32 is arranged behind each of the fans 52A to 52D.

  The fans 52A to 52D are arranged so as to face the pair of downstream radiators 53A and 53B with the pair of upstream radiators 54A and 54B sandwiching the pair of downstream radiators 53A and 53B and sucking outside air. Therefore, it is configured by an intake fan that generates the airflows a to d of the cooling air. The fans 52A and 52B are mounted vertically adjacent to each other at the rear position of the downstream radiator 53A, and the fans 52C and 52D are mounted vertically adjacent to each other at the rear position of the downstream radiator 53B. There is.

  Further, electric motors 59A to 59D for rotating the fans 52A to 52D are attached to the rear sides of the fans 52A to 52D. Each of the fans 52A to 52D has an outer diameter set to a dimension close to the lateral width of the downstream radiators 53A and 53B and the upstream radiators 54A and 54B. Thus, the fans 52A to 52D can pass the cooling airflows a to d through all the flow paths inside the downstream radiators 53A and 53B and the upstream radiators 54A and 54B.

  The downstream radiators 53A and 53B are high-temperature radiators that are arranged adjacent to each other in a direction that traverses the cooling air, that is, in the left-right direction, and have a relatively high temperature because the engine cooling water A flows. Although not shown, the downstream radiators 53A and 53B are connected to a plurality of pipe-shaped flow passages (hereinafter simply referred to as cores) for circulating the engine cooling water A in the vertical direction.

  The surface of each core is provided with bellows fins (not shown) for increasing the heat exchange area between the engine cooling water A and the cooling airflows a to d. A partition (not shown) is installed between the adjacent downstream radiators 53A and 53B to prevent the cooling airflows a to d generated by the fans 52A to 52D from interfering with each other.

  The upstream radiators 54A and 54B are low-temperature radiators that are arranged adjacent to each other in a direction crossing the cooling air, that is, in the left-right direction, and have a relatively low temperature because the supercharger cooling water B flows. Although not shown, a plurality of cores for circulating the supercharger cooling water B in the vertical direction are connected to the upstream radiators 54A and 54B.

  The surface of each core is provided with a bellows-like fin (not shown) for increasing the heat exchange area between the supercharger cooling water B and the cooling airflows a to d. A partition (not shown) is installed between the adjacent upstream radiators 54A and 54B to prevent the cooling airflows a to d generated by the fans 52A to 52D from interfering with each other.

  The first circulation circuit 57 is provided between the downstream radiators 53A and 53B and the engine 32, and is composed of pipe lines 57A and 57B through which the engine cooling water A circulates. The pipe line 57A has one end connected to the engine 32 via the thermostat 60, branches in the middle between the downstream radiators 53A, 53B and the engine 32, and the other end at the upper ends of the downstream radiators 53A, 53B. Each is connected.

  The thermostat 60 has a function of opening and closing according to the temperature TA of the engine cooling water A flowing to each of the downstream radiators 53A and 53B, and is opened when the temperature TA of the engine cooling water A is equal to or higher than a predetermined temperature Ta1, for example. Accordingly, the engine cooling water A is circulated to the downstream side of the first circulation circuit 57, and is closed when the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta1, so that the engine cooling water A is closed. It is returned to the circuit inside the engine 32 again without being circulated to the downstream side.

  The pipe 57B has one end connected to the engine 32, branches midway between the downstream radiators 53A and 53B and the engine 32, and the other ends connected to the lower ends of the downstream radiators 53A and 53B, respectively. .. Therefore, both the engine 32 and the downstream radiators 53A and 53B are connected in parallel via the conduits 57A and 57B.

  An engine cooling water temperature sensor 72A (see FIG. 5) serving as a first refrigerant temperature detecting unit that detects the temperature TA of the engine cooling water A is attached to the pipe 57B on the side where the engine cooling water A returns to the engine 32. There is. Further, an engine cooling water flow rate sensor (not shown) that detects the flow rate of the engine cooling water A is attached to the conduit 57B. The engine cooling water temperature sensor 72A and the engine cooling water flow rate sensor are electrically connected to the control device 71.

  A portion of the pipe 57A closer to the downstream radiators 53A and 53B than the branch point has a pair of first opening / closing sections that communicate or block the flow paths of the engine cooling water A flowing to the pair of downstream radiators 53A and 53B, respectively. First control valves (hereinafter, simply abbreviated as control valves) 61A and 61B as valves are attached. The control valves 61A and 61B open and close in accordance with a control command from the control device 71 to control the circulation of the engine cooling water A flowing to the downstream radiators 53A and 53B.

  The second circulation circuit 58 is provided between the upstream radiators 54A and 54B and the engine 32, and is composed of pipe lines 58A and 58B through which the supercharger cooling water B circulates. The pipe line 58A has one end connected to the engine 32 via the thermostat 62, branches in the middle between the upstream radiators 54A and 54B and the engine 32, and the other end to the upper ends of the upstream radiators 54A and 54B. Each is connected.

  The thermostat 62 has a function of opening and closing according to the temperature TB of the supercharger cooling water B flowing to the upstream radiators 54A and 54B. For example, the temperature TB of the supercharger cooling water B is equal to or higher than a predetermined temperature Tb1. When the temperature TB of the supercharger cooling water B is lower than a predetermined temperature Tb1, the supercharger cooling water B is circulated to the downstream side of the second circulation circuit 58 by being opened at The cooling water B is not returned to the downstream side of the second circulation circuit 58 and is returned to the internal circuit of the engine 32 again.

  The pipe 58B has one end connected to the engine 32, a branch in the middle between the upstream radiators 54A and 54B and the engine 32, and the other end connected to the lower ends of the upstream radiators 54A and 54B, respectively. .. Therefore, both the engine 32 and the upstream radiators 54A and 54B are connected in parallel via the conduits 58A and 58B.

  In the pipe line 58B on the side where the supercharger cooling water B returns to the engine 32, the supercharger cooling water temperature sensor 72B (FIG. 5) serving as a second refrigerant temperature detection unit that detects the temperature TB of the supercharger cooling water B (FIG. Installed). Further, a supercharger cooling water flow rate sensor that detects the flow rate of the supercharger cooling water B is attached to the conduit 58B. The supercharger cooling water temperature sensor 72B and the supercharger cooling water flow rate sensor are electrically connected to the control device 71.

  A portion of the pipe 58A closer to the upstream radiators 54A and 54B than the branch point is configured to connect or block a flow path of the supercharger cooling water B flowing to the pair of upstream radiators 54A and 54B, respectively. Second control valves (hereinafter, simply abbreviated as control valves) 63A and 63B as two on-off valves are attached. The control valves 63A and 63B control the circulation of the supercharger cooling water B flowing to the upstream radiators 54A and 54B by opening and closing according to the control command from the control device 71.

  The brake oil cooler 55 has a brake oil circulation circuit (not shown) through which the brake oil C flows between the traveling motors 40L and 40R. The brake oil cooler 55 is located so as to face the lower side of the upstream radiator 54A, and cools the brake oil C in the brake oil circulation circuit by passing the cooling airflow b.

  A brake oil temperature sensor 72C (see FIG. 5) that detects the temperature TC of the brake oil C is attached to the brake oil circulation circuit. A brake oil flow sensor (not shown) for detecting the flow rate of the brake oil C is attached to the brake oil circulation circuit. The brake oil temperature sensor 72C and the brake oil flow rate sensor are electrically connected to the control device 71.

  The air conditioner condenser 56 has an air conditioner refrigerant circulation circuit (not shown) through which the air conditioner refrigerant D flows between it and a refrigeration system (not shown). The air conditioner condenser 56 is located so as to face the lower side of the upstream radiator 54B, and cools the air conditioner refrigerant D in the air conditioner refrigerant circulation circuit by passing the air flow d of the cooling air.

  An air conditioner refrigerant temperature sensor 72D (see FIG. 5) that detects the temperature TD of the air conditioner refrigerant D is attached to the air conditioner refrigerant circulation circuit. An air conditioner refrigerant flow sensor (not shown) that detects the flow rate of the air conditioner refrigerant D is attached to the air conditioner refrigerant circulation circuit. The air conditioner refrigerant temperature sensor 72D and the air conditioner refrigerant flow rate sensor are electrically connected to the control device 71.

  Each of the electric motors 59A to 59D is electrically connected to the auxiliary inverter 38 and the control device 71, and independently operates or stops according to a control command from the control device 71, or rotates the fans 52A to 52D. Number adjustments can be made.

  In the cooling device 51 configured in this way, the engine cooling water A exchanges heat with each part of the engine 32 by flowing in the vicinity of each cylinder of the engine 32 and other parts. The supercharger cooling water B exchanges heat with the gas that is compressed and introduced into the supercharger by flowing through the supercharger of the engine 32.

  Then, as shown in FIG. 4, the engine cooling water A that has circulated in the engine 32 flows into the conduit 57A via the thermostat 60 by a pump (not shown), passes through the control valves 61A and 61B, and then the arrow A1. , A2, they pass through the insides of the downstream radiators 53A, 53B from the upper side to the lower side, and then flow back to the engine 32 via the pipe line 57B. Similarly, the supercharger cooling water B flowing through the engine 32 flows into the pipe 58A via the thermostat 62 by a pump (not shown), passes through the control valves 63A and 63B, and then is shown by arrows B1 and B2. First, it passes through the inside of the upstream radiators 54A and 54B from the upper side to the lower side, and then returns to the engine 32 again via the pipe line 58B.

  On the other hand, when the fans 52A to 52D are operated, cooling airflows a to d are generated from the front to the rear. The air flow a of the cooling air from the fan 52A mainly passes through the upper portions of the upstream radiator 54A and the downstream radiator 53A, that is, the relatively upstream sides of the supercharger cooling water B and the engine cooling water A. The feeder cooling water B and the engine cooling water A are cooled. Similarly, the air flow b of the cooling air by the fan 52B mainly includes the brake oil cooler 55 and the lower portions of the upstream radiator 54A and the downstream radiator 53A, that is, each brake oil C, the supercharger cooling water B, and the engine cooling water. The brake oil C, the supercharger cooling water B, and the engine cooling water A are cooled by passing relatively downstream of A.

  Furthermore, the air flow c of the cooling air from the fan 52C passes through the upper portions of the upstream radiator 54B and the downstream radiator 53B, that is, the relatively upstream sides of the supercharger cooling water B and the engine cooling water A. The supercharger cooling water B and the engine cooling water A are cooled. Similarly, the air flow d of the cooling air from the fan 52D mainly includes the air conditioner condenser 56 and the lower portions of the upstream radiator 54B and the downstream radiator 53B, that is, each air conditioner refrigerant D, the supercharger cooling water B, and the engine cooling water A. The air conditioner refrigerant D, the supercharger cooling water B, and the engine cooling water A are cooled by passing a relatively downstream side thereof.

  Further, the cooling airflows a to d hit the surface of the engine 32 after passing through the fans 52A to 52D, and increase the heat transfer coefficient of the surface of the engine 32. Reference numeral 64 shown in FIG. 4 is a casing that guides the cooling air from the front to the rear by covering the upstream radiators 54A and 54B, the downstream radiators 53A and 53B, and the cooling fans 52A to 52D.

  Next, a specific configuration showing the function of the control device 71 according to the first embodiment of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 5, the control device 71 controls the engine cooling water temperature sensor 72A, the supercharger cooling water temperature sensor 72B, the brake oil temperature sensor 72C, and the air conditioner refrigerant temperature sensor 72D from the engine cooling water A and the supercharger cooling. The temperature information of the water B, the brake oil C, and the air conditioner refrigerant D is input, and a control command is output to the control valves 61A, 61B, 63A, 63B and the electric motors 59A to 59D.

  Further, the control device 71 includes a fan control unit 711 as a fan driving unit that drives the fans 52A to 52D via the electric motors 59A to 59D, and the fans 52A to 52D are driven by the fan control unit 711 so that the cooling airflow. An opening / closing control unit 712 that controls opening / closing operations of the control valves 61A, 61B, 63A, 63B so that at least one of the engine cooling water A and the supercharger cooling water B passes through only the areas where a to d occur. It is configured to include.

  Specifically, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the opening command for the control valves 61A, 61B, 63A, 63B. A predetermined relationship F1 with the operation command of the fans 52 to 52D is stored in advance in a storage device such as an internal HDD.

  The fan control unit 711 includes a temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A, a temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B, and a brake oil temperature sensor. Based on the temperature TC of the brake oil C detected by the 72C, the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D, and the relationship F1 stored in the storage device, the operation commands for the fans 52A to 52D are issued. To generate. The fan control unit 711 controls the operations of the fans 52A to 52D by transmitting the generated operation command to the corresponding electric motors 59A to 59D.

  The opening / closing control unit 712 includes a temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A, a temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B, and a brake oil temperature sensor. Based on the temperature TC of the brake oil C detected by 72C, the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D, and the relationship F1 stored in the storage device, the control valves 61A, 61B, 63A, 63B open command is generated. The opening / closing control unit 712 controls the operations of the control valves 61A, 61B, 63A, 63B by transmitting the generated opening command to the corresponding control valves 61A, 61B, 63A, 63B.

  FIG. 6 shows temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D stored in the control device 71, the opening command of the control valves 61A, 61B, 63A, 63B, and the fan. It is a figure which shows the relationship F1 with the operation command of 52A-52D.

  In FIG. 6, when 1 is entered in each column of engine cooling water A, supercharger cooling water B, brake oil C, and air conditioner refrigerant D in the temperature information, it is necessary to cool them. Indicates. On the other hand, when the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D are blank in the temperature information, it does not matter whether or not they need to be cooled. ..

  When 1 is entered in each column of the opening command of the control valves 61A, 61B, 63A, 63B and the operation commands of the fans 52A to 52D, the opening command is output from the control device 71 and the corresponding control valve 61A, 61B, 63A, 63B are in an open state (a state in which the refrigerant can flow), and an operation command for the fans 52A to 52D is output from the control device 71, and the fans 52A to 52D are operated.

  In addition, when each column of the opening command of the control valves 61A, 61B, 63A, 63B and the operation commands of the fans 52A to 52D is blank, the opening command of the control valves 61A, 61B, 63A, 63B and the fan are not necessarily output from the control device 71. This indicates that the operation commands of 52A to 52D are not output. Actually, there is a possibility that a plurality of pieces of temperature information among the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D will be 1. In that case, control is performed by the logical sum (OR) of them. An opening command for the valves 61A, 61B, 63A, 63B and an operation command for the fans 52A to 52D are output.

  When the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D becomes equal to or higher than the predetermined temperature Td and the temperature information of the air conditioner refrigerant D becomes 1, the fan control unit 711 generates an operation command for the fan 52D. It transmits to the electric motor 59D (line 01). As a result, the electric motor 59D rotates the fan 52D in accordance with the operation command from the fan control unit 711, so that an air flow d of cooling air passing through the air conditioner condenser 56 is generated.

  When the temperature TC of the brake oil C detected by the brake oil temperature sensor 72C becomes equal to or higher than a predetermined temperature Tc and the temperature information of the brake oil C becomes 1, the fan control unit 711 generates an operation command for the fan 52B. It is transmitted to the electric motor 59B (line 02). As a result, the electric motor 59B rotates the fan 52B in accordance with the operation command from the fan control unit 711, so that the cooling airflow b passing through the brake oil cooler 55 is generated.

  Here, lines 03 to 06 shown in FIG. 6 indicate that the temperature information of the supercharger cooling water B is 1 and that the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B is TB. The temperature TB of the supercharger cooling water B is the lowest in row 03, and the temperature TB of the supercharger cooling water B is higher as the row number increases. ..

  When the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B becomes equal to or higher than a predetermined temperature Tb1 (<Tb2) and the temperature information of the supercharger cooling water B becomes 1, opening / closing control is performed. The unit 712 generates an opening command for the control valve 63A and sends it to the control valve 63A, and the fan control unit 711 generates an operation command for the fan 52A and sends it to the electric motor 59A (line 03). As a result, as shown in FIG. 7, the control valve 63A opens in accordance with the opening command from the opening / closing control unit 712, so that the supercharger cooling water B flows in the upstream radiator 54A. Further, when the electric motor 59A rotates the fan 52A in accordance with the operation command from the fan control unit 711, an air flow a of cooling air passing through the upstream side of the supercharger cooling water B of the upstream radiator 54A is generated.

  When the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B becomes equal to or higher than a predetermined temperature Tb2 (<Tb3), the fan control unit 711 further generates an operation command for the fan 52B. It transmits to the electric motor 59B (line 04). As a result, the electric motor 59B rotates the fan 52B in accordance with the operation command from the fan control unit 711, and in addition to the air flow a of the cooling air, the cooling that passes the downstream side of the supercharger cooling water B of the upstream radiator 54A. A wind flow b is generated.

  When the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B becomes equal to or higher than a predetermined temperature Tb3 (<Tb4), the opening / closing control unit 712 further generates an opening command for the control valve 63B. The fan control unit 711 generates an operation command for the fan 52C and sends it to the electric motor 59C (row 05). As a result, the electric motor 59C rotates the fan 52C in accordance with the operation command from the fan control unit 711, so that in addition to the airflows a and b of the cooling air, it passes through the upstream side of the supercharger cooling water B of the upstream side radiator 54B. A cooling air flow c is generated.

  When the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B becomes equal to or higher than the predetermined temperature Tb4, the fan control unit 711 further generates an operation command for the fan 52D and sends it to the electric motor 59D. Send (line 06). As a result, the electric motor 59D rotates the fan 52D in accordance with the operation command from the fan control unit 711, so that in addition to the cooling airflows a to c, the upstream radiator 54B passes through the downstream side of the supercharger cooling water B. An air flow d of cooling air is generated.

  As described above, the fans 52A and 52C located upstream of the supercharger cooling water B of the upstream radiators 54A and 54B are located downstream of the supercharger cooling water B of the upstream radiators 54A and 54B. 52B and 52D operate (that is, in a state where the temperature TB of the supercharger cooling water B is lower) generally because the difference between the temperature TB of the supercharger cooling water B and the temperature of the outside air is upstream. This is because the side radiators 54A and 54B are larger on the upstream side than on the downstream side of the supercharger cooling water B, so that a higher heat exchange effect can be obtained with the same fan power.

  Similarly, in lines 07 to 10 shown in FIG. 6, the state in which the temperature information of the engine cooling water A is 1 is further 4 according to the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A. The temperature TA of the engine cooling water A is lowest in the row 07, and the temperature TA of the engine cooling water A is higher as the row number increases.

  When the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than a predetermined temperature Ta1 (<Ta2) and the temperature information of the engine cooling water A becomes 1, the opening / closing control unit 712 causes the control valve The fan control unit 711 generates an operation command for the fan 52A and transmits it to the electric motor 59A while generating an opening command for 61A and transmitting it to the control valve 61A (line 07). As a result, the control valve 61A opens according to the opening command from the opening / closing control unit 712, so that the engine cooling water A flows through the inside of the downstream radiator 53A. Further, when the electric motor 59A rotates the fan 52A in accordance with the operation command from the fan control unit 711, a cooling airflow a passing through the upstream side of the engine cooling water A of the downstream side radiator 53A is generated.

  When the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than a predetermined temperature Ta2 (<Ta3), the fan control unit 711 further generates an operation command for the fan 52B and sends it to the electric motor 59B. Send (line 08). As a result, the electric motor 59B rotates the fan 52B according to the operation command from the fan control unit 711, so that in addition to the cooling air flow a, the cooling air passing through the downstream side of the engine cooling water A of the downstream side radiator 53A is generated. Airflow b is generated.

  When the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than a predetermined temperature Ta3 (<Ta4), the opening / closing control unit 712 further generates an opening command for the control valve 61B to generate the control valve 61B. At the same time, the fan control unit 711 generates an operation command for the fan 52C and sends it to the electric motor 59C (line 09). As a result, the electric motor 59C rotates the fan 52C in accordance with the operation command from the fan control unit 711, so that the cooling airflows a and b as well as the cooling air that passes through the upstream side of the engine cooling water A of the downstream side radiator 53B are cooled. An air flow c of wind is generated.

  When the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than the predetermined temperature Ta4, the fan control unit 711 further generates an operation command of the fan 52D and transmits it to the electric motor 59D (line 10). As a result, the electric motor 59D rotates the fan 52D in accordance with the operation command from the fan control unit 711, and in addition to the cooling airflows a to c, the cooling that passes through the downstream side of the engine cooling water A of the downstream side radiator 53B. A wind flow d is generated.

  In this way, the fans 52A and 52C located on the upstream side of the engine cooling water A of the downstream side radiators 53A and 53B are closer to the fans 52B and 52D located on the downstream side of the engine cooling water A of the downstream side radiators 53A and 53B. The first operation (that is, the state in which the temperature TA of the engine cooling water A is lower) also operates for the same reason as the description of the supercharger cooling water B described above.

  Next, the control process of the cooling device 51 by the control device 71 according to the first embodiment of the present invention will be described in detail with reference to the flowchart of FIG. Note that the following description shows the control processing when cooling the engine cooling water A, but the control processing when cooling the supercharger cooling water B is also the same, so redundant description will be omitted. ..

  As shown in FIG. 8, first, the control device 71 acquires the temperature TA of the engine cooling water A from the engine cooling water temperature sensor 72A (step (hereinafter, referred to as S) 801), and then the temperature TA of the engine cooling water A. It is determined whether is lower than the predetermined temperature Ta1 (S802). At this time, when the control device 71 determines that the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta1 (S802 / Yes), the opening / closing control unit 712 generates a command to close the control valves 61A and 61B, and generates the command. The closed command is transmitted to the control valves 61A and 61B (S803).

  Next, the fan control unit 711 generates a stop command for the fans 52A and 52B, and transmits the generated stop command to the electric motors 59A and 59B, respectively (S804). Subsequently, the fan control unit 711 generates a stop command for the fans 52C and 52D, and transmits the generated stop commands to the electric motors 59C and 59D (S805), and then the processing from S801 is repeated.

  On the other hand, in S802, when the control device 71 determines that the temperature TA of the engine cooling water A is equal to or higher than the predetermined temperature Ta1 (S802 / No), whether the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta3. It is determined whether or not (S806). At this time, when the control device 71 determines that the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta3 (S806 / No), the opening / closing control unit 712 issues an opening command for the control valve 61A and a closing command for the control valve 61B. Is generated, and the generated open command and close command are transmitted to the control valves 61A and 61B, respectively (S807).

  Subsequently, the fan control unit 711 generates a stop command for the fans 52C and 52D, and transmits the generated stop command to the electric motors 59C and 59D, respectively (S808). Next, the control device 71 determines whether or not the temperature TA of the engine cooling water A is lower than a predetermined temperature Ta2 (S809). At this time, when the control device 71 determines that the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta2 (S809 / Yes), the fan control unit 711 generates an operation command for the fan 52A and a stop command for the fan 52B. Then, after transmitting the generated operation command and stop command to the electric motors 59A and 59B (S810), the processing from S801 is repeated.

  In S809, when the control device 71 determines that the temperature TA of the engine cooling water A is equal to or higher than the predetermined temperature Ta2 (S809 / No), the fan control unit 711 generates and generates operation commands for the fans 52A and 52B. After transmitting the operation command to each of the electric motors 59A and 59B (S811), the processing from S801 is repeated.

  On the other hand, when the control device 71 determines in S806 that the temperature TA of the engine cooling water A is equal to or higher than the predetermined temperature Ta3 (S806 / No), the opening / closing control unit 712 generates an opening command for the control valves 61A and 61B. , And transmits the generated open command to the control valves 61A and 61B, respectively (S812).

  Subsequently, the fan control unit 711 generates operation commands for the fans 52A and 52B, and transmits the generated operation commands to the electric motors 59A and 59B, respectively (S813). Next, the control device 71 determines whether or not the temperature TA of the engine cooling water A is lower than a predetermined temperature Ta4 (S814). At this time, when the control device 71 determines that the temperature TA of the engine cooling water A is lower than the predetermined temperature Ta4 (S813 / Yes), the fan control unit 711 generates an operation command for the fan 52C and a stop command for the fan 52D. Then, after transmitting the generated operation command and stop command to the electric motors 59C and 59D (S815), the processing from S801 is repeated.

  In S814, when the control device 71 determines that the temperature TA of the engine cooling water A is equal to or higher than the predetermined temperature Ta4 (S814 / No), the fan control unit 711 generates and generates operation commands for the fans 52C and 52D. After transmitting the operation command to each of the electric motors 59C and 59D (S816), the processing from S801 is repeated.

  By such processing, as shown in FIG. 9, the control processing results of the downstream radiators 53A and 53B for the fans 52A to 52D are obtained. Specifically, after the processing of S805 ends, the cooling function (heat exchange function) of the downstream radiator 53A for the fans 52A and 52B is in an OFF state, and the cooling function (heat exchange function of the downstream radiator 53B for the fans 52C and 52C is ) Is turned off. After the process of S810 is completed, the cooling function of the downstream radiator 53A for the fan 52A is in the ON state, the cooling function of the downstream radiator 53A for the fan 52B is in the OFF state, and the cooling function of the downstream radiator 53B for the fans 52C and 52D is OFF. It becomes a state.

  After the processing of S811, the cooling function of the downstream radiator 53A for the fans 52A and 52B is in the ON state, and the cooling function (heat exchange function) of the downstream radiator 53B for the fans 52C and 52D is in the OFF state. After the processing of S815 ends, the cooling function of the downstream radiator 53A for the fans 52A and 52B is ON, the cooling function of the downstream radiator 53B for the fan 52C is ON, and the cooling function of the downstream radiator 53B for the fan 52D is OFF. It becomes a state.

  After the processing of S816 ends, the cooling function of the downstream radiator 53A for the fans 52A and 52B is ON, and the cooling function of the downstream radiator 53B for the fans 52C and 52D is ON. When the control processing result when cooling the engine cooling water A is different from the control processing result when cooling the supercharger cooling water B, the fan operation command is the logical sum (OR) of both control processing results. ).

  In the first embodiment of the present invention, the processes of S803, S807, and S812 correspond to the opening / closing control step, and the processes of S804, S805, S808, S810, S811, S813, S815, and S816 correspond to the fan driving step, respectively.

  According to the dump truck 1 according to the first embodiment of the present invention configured as described above, the opening / closing control unit 712 causes the control valves 61A, 61B of the pipelines 57A, 57B, 58A, 58B that connect the respective devices of the cooling device 51. , 63A, 63B are opened and closed to connect or block the flow passages of the engine cooling water A and the supercharger cooling water B to the downstream radiators 53A, 53B and the upstream radiators 54A, 54B, respectively, to thereby connect the cooling water inside the cooling device 51. The passages of the engine cooling water A and the supercharger cooling water B can be easily changed.

  As a result, when a specific fan among the fans 52A to 52D is stopped, it is possible to prevent the engine cooling water A and the supercharger cooling water B from passing through a region where the cooling airflows a to d are not generated. Therefore, heat exchange between the engine cooling water A and the supercharger cooling water B and the cooling air can be efficiently performed. As a result, fan power can be reduced and fuel consumption can be sufficiently suppressed.

  Further, in the dump truck 1 according to the first embodiment of the present invention, four types of heat exchangers, that is, the downstream radiators 53A and 53B, the upstream radiators 54A and 54B, the brake oil cooler 55, and the air conditioner condenser 56 are respectively provided. Depending on the temperature information of each of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D passing through, the circulation of the heat exchanger of each of these refrigerants and the cooling air passing through the heat exchanger It becomes possible to control the generation of the air flows a to d in the optimum state. Therefore, it is possible to further reduce the fan power consumed to generate the corresponding cooling airflows a to d with respect to the heat exchanger through which the refrigerant that does not need to be cooled flows.

  Further, in the dump truck 1 according to the first embodiment of the present invention, the flow path of the engine cooling water A from the engine 32 to the downstream radiators 53A and 53B, and the supercharger from the engine 32 to the upstream radiators 54A and 54B. The control valves 61A, 61B, 63A, 63B are connected to the radiators 53A, 53B and upstream of the branch points of the conduits 57A, 57B, 58A, 58B in order to communicate or block the flow paths of the cooling water B, respectively. It suffices to attach it to the side radiators 54A and 54B. As described above, in the first embodiment of the present invention, the function for changing the passages of the engine cooling water A and the supercharger cooling water B in the cooling device 51 can be realized with a simple configuration, and thus the cooling device 51. Manufacturing cost can be reduced.

  Further, in the dump truck 1 according to the first embodiment of the present invention, the fans 52A to 52D are arranged between the downstream radiators 53A and 54B so as to face the downstream radiators 53A and 53B. Since the outer diameters of the fans 52A to 52D are set to be substantially equal to the lateral widths of the downstream side radiators 53A and 53B and the upstream side radiators 54A and 54B with respect to all the cores included in these devices, The cooling airflows a to d can be passed.

  Therefore, there is no refrigerant that returns to the engine 32 without being heat-exchanged with the cooling air generated by the fans 52A to 52D, and in the downstream radiators 53A and 53B and the upstream radiators 54A and 54B, desired heat can be generated with smaller fan power. The exchange amount can be obtained. Thereby, energy saving of the cooling device 51 can be achieved.

  In the first embodiment of the present invention, as the four types of heat exchangers, the downstream radiators 53A and 53B, the upstream radiators 54A and 54B, the brake oil cooler 55, and the air conditioner condenser 56 are housed in the grill box 19. However, the present invention is not limited to this case, and the brake oil cooler 55 and the air conditioner condenser 56 may not be housed in the grill box 19, for example.

  Further, in the description of the functional configuration of the control device 71 using FIG. 6, the case where all the operation commands of the fans 52A to 52D for cooling the four types of heat exchangers are independently output has been shown. The controller 71 does not necessarily need to perform such control. For example, when the engine cooling water A and the supercharger cooling water B show similar temperature change tendencies according to the operating state of the engine 32, The line 03 and the line 07, the line 04 and the line 08, the line 05 and the line 09, and the line 06 and the line 10 may be unified to simplify the control logic accordingly.

  Further, in the description of the functional configuration of the control device 71 using FIG. 6, the case where the fans 52A to 52D are operated has been shown, but as described above, the electric motors 59A to 59D that drive the fans 52A to 52D are inverters. Since it is controlled, the advantage may be utilized to perform control to change the rotation speeds of the fans 52A to 52D according to the flow rate and temperature of each refrigerant.

  Further, in the description of the functional configuration of the control device 71 using FIG. 6, the operation commands of the fans 52A to 52D facing the upper and lower portions of the downstream radiators 53A and 53B and the upstream radiators 54A and 54B are engine cooling water. Although the case where the temperature is independently output according to the temperatures TA and TB of the cooling water B of A and the supercharger is shown, the fans located at the top and bottom are reduced for the purpose of reducing the number of auxiliary inverters or simplifying control. Each of 52A, 52B and the fans 52C, 52D may be controlled by a single inverter so that they always have the same rotational speed.

  Further, in the cooling device 51 according to the first embodiment of the present invention, a portion of the conduit 57A that is closer to the downstream radiators 53A and 53B than the branch point, and a portion of the conduit 58A that is upstream of the branch point from the branch point 54A, 54A, The case where the control valves 61A, 61B, 63A, 63B are respectively provided in the portions close to 54B has been described. This is because the engine cooling water A and the supercharger in the parallel portion of each of the first circulation circuit 57 and the second circulation circuit 58 are described. The branching of the flow path of the cooling water B is only one method of controlling it according to the state, and another method may be adopted.

  For example, in the first embodiment of the present invention, the control valves 61A and 63A may be eliminated substantially. This is a situation in which all the control valves 61A, 61B, 63A, 63B are closed (that is, the temperatures TA, TB of the engine cooling water A and the supercharger cooling water B are less than Ta1, Tb1, respectively). This is because the circulation of each engine cooling water A and the supercharger cooling water B is blocked by the thermostats 60 and 62 located upstream of these.

  In addition, the first embodiment of the present invention has a plurality of thermostats (first thermostat and first thermostat, which have the same functions as the thermostats 60 and 62 and operate at different temperatures, instead of the control valves 61A, 61B, 63A and 63B. A second thermostat) may be attached to the conduits 57A and 58B. In this case, since the generation and output of the control valve opening command by the opening / closing control unit 712 can be omitted, the calculation load of the control device 71 can be reduced.

  Further, in the first embodiment of the present invention, the case where the fans 52A to 52D are rotated by the electric motors 59A to 59D has been described, but the present invention is not limited to this case, and the electric motors 59A to 59D are not limited thereto. Instead, a plurality of hydraulic motors that rotate the fans 52A to 52D by hydraulic pressure may be used.

[Second Embodiment]
In the dump truck 1 according to the second embodiment of the present invention, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the control valves 61A, A predetermined relationship F2 between the opening command of 61B, 63A, 63B and the operation command of the fans 52 to 52D is stored in advance in a storage device such as an internal HDD. This relationship F2 is obtained by partially changing the combination of the opening command for the control valves 61A, 61B, 63A, 63B and the operation commands for the fans 52A to 52D shown in FIG. 6 described in the first embodiment. The other configurations of the second embodiment are the same as the configurations of the first embodiment, and the same or corresponding portions will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 10 shows temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D stored in the control device 71, the opening command of the control valves 61A, 61B, 63A, 63B, and the fan. It is a figure which shows the relationship F2 with the operation command of 52A-52D. The shaded column in the figure shows the difference from the relationship F1 of FIG. 6 described in the first embodiment.

  In FIG. 10, when the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than a predetermined temperature Ta1 and the temperature information of the engine cooling water A becomes 1, the opening / closing control unit 712 controls The fan control unit 711 generates an operation command for the fan 52C and transmits it to the electric motor 59C while generating an opening command for the valve 61B and transmitting it to the control valve 61B (line 07). As a result, the control valve 61B opens in accordance with the opening command from the opening / closing control unit 712, so that the engine cooling water A flows in the downstream radiator 53B. Further, the electric motor 59C rotates the fan 52C in accordance with an operation command from the fan control unit 711, so that an air flow c of cooling air passing through the upstream side of the engine cooling water A of the downstream side radiator 53B is generated.

  When the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A becomes equal to or higher than the predetermined temperature Ta2, the fan control unit 711 further generates an operation command of the fan 52D and transmits it to the electric motor 59D (line 08). As a result, the electric motor 59D rotates the fan 52D in accordance with the operation command from the fan control unit 711, and in addition to the cooling air flow c, the cooling air passing through the downstream side of the engine cooling water A of the downstream radiator 53B is generated. Airflow d is generated.

  That is, the downstream radiator 53B is a fan with the upstream radiator 54A through which the supercharger cooling water B flows when the temperature TB of the supercharger cooling water B is relatively low (for example, row 03, row 04). The airflows a and b of the cooling air due to 52A and 52B do not communicate (that is, the airflows a to d of the cooling air do not communicate with both the upstream radiator 54A and the downstream radiator 53B).

  According to the dump truck 1 according to the second embodiment of the present invention configured as described above, the same operation and effect as those of the above-described first embodiment can be obtained, and the temperature TA of the engine cooling water A is temporarily set to the predetermined temperature Ta1. When it is above (row 07) and when the temperature TB of the supercharger cooling water B becomes equal to or higher than the predetermined temperature Tb1 (row 03), the cooling airflows c and d passing through the downstream radiator 53B are: Even if it passes through the upstream radiator 54B before that, it will not be warmed and its temperature will not rise, so that a large temperature difference with the engine cooling water A can be maintained.

  Therefore, the second embodiment of the present invention can obtain a desired amount of heat exchange of the engine cooling water A with respect to the cooling air only by using a smaller fan power, so that the engine compared to the first embodiment. The fan power required for cooling the cooling water A is reduced, and the fuel consumption can be suppressed more effectively.

[Third Embodiment]
The third embodiment of the present invention is different from the above-described first embodiment in that, in the first embodiment, as shown in FIG. 4, the brake oil cooler 55 passes the air flow b of the cooling wind by the fan 52B. In addition, the air conditioner condenser 56 is arranged so as to face the lower side of the upstream radiator 54A, and the air conditioner condenser 56 is arranged so as to face the lower side of the upstream radiator 54B so that the air flow d of the cooling air by the fan 52D passes through. On the other hand, in the third embodiment, as shown in FIG. 11, the brake oil cooler 55 is arranged facing the upper side of the upstream radiator 54A so that the air flow a of the cooling air by the fan 52A passes through, That is, the air conditioner condenser 56 is arranged to face the upper side of the upstream radiator 54B so that the air flow c of the cooling air from the fan 52C passes through.

  In this case, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the opening command of the control valves 61A, 61B, 63A, and 63B. A predetermined relationship F3 with the operation command of the fans 52 to 52D is stored in advance in a storage device such as an internal HDD. This relationship F3 is obtained by partially changing the combination of the operation commands of the fans 52A to 52D shown in FIG. 6 described in the first embodiment. The other configurations of the third embodiment are the same as the configurations of the first embodiment, and the same or corresponding portions will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 12 shows temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D stored in the control device 71, the opening command of the control valves 61A, 61B, 63A, 63B, and the fan. It is a figure which shows the relationship F3 with the operation command of 52A-52D. The shaded column in the figure shows the difference from the relationship F1 of FIG. 6 described in the first embodiment.

  In FIG. 12, when the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D becomes equal to or higher than the predetermined temperature Td and the temperature information of the air conditioner refrigerant D becomes 1, the fan control unit 711 causes the fan 52C to operate. A command is generated and transmitted to the electric motor 59C (line 01). As a result, the electric motor 59C rotates the fan 52C in accordance with the operation command from the fan control unit 711, so that the cooling airflow c passing through the air conditioner condenser 56 is generated.

  When the temperature TC of the brake oil C detected by the brake oil temperature sensor 72C becomes equal to or higher than a predetermined temperature Tc and the temperature information of the brake oil C becomes 1, the fan control unit 711 generates an operation command for the fan 52A. Transmission to the electric motor 59A (line 02). As a result, the electric motor 59A rotates the fan 52A in accordance with the operation command from the fan control unit 711, so that a cooling airflow a passing through the brake oil cooler 55 is generated.

  According to the dump truck 1 according to the third embodiment of the present invention configured as described above, the same operational effects as those of the above-described first embodiment can be obtained, and the temperature TA of the engine cooling water A is temporarily set to the predetermined temperature Ta1. When the temperature TB of the supercharger cooling water B is equal to or higher than the predetermined temperature Tb1 (row 03) (Row 03), the opening / closing control is performed when the temperature TC of the brake oil C reaches the predetermined temperature Tc. Since the unit 712 only needs to generate and output the operation command for the fan 52A, the number of fans 52A to 52D to be operated is reduced, and the fan power can be reduced accordingly.

  When the temperature TA of the engine cooling water A is equal to or higher than the predetermined temperature Ta3 (row 09) and the temperature TB of the supercharger cooling water B is equal to or higher than the predetermined temperature Tb3 (row 05), the air conditioner refrigerant D is cooled. When the temperature TD reaches the predetermined temperature Td, it is not necessary to operate the fan 52D, so that the fan power can be reduced accordingly.

  Although the third embodiment of the present invention has been described with respect to the case where the brake oil cooler 55 and the air conditioner condenser 56 are arranged to face the upper sides of the upstream radiators 54A and 54B, the present invention is not limited to this case. However, the mounting positions of the brake oil cooler 55 and the air conditioner condenser 56 may be replaced with each other.

[Fourth Embodiment]
The fourth embodiment of the present invention is different from the above-described second embodiment in that a cooling device 51 according to the second embodiment includes four fans 52A to 52D that take in outside air into the inside to generate cooling air, and these. While the electric motors 59A to 59D for rotating the fans 52A to 52D are provided, the cooling device 51 according to the fourth embodiment has an outer diameter larger than that of the fans 52A to 52D as shown in FIG. Is set to be large, and a single fan 52 for generating cooling airflows a to d and an electric motor (not shown) for rotating the fan 52 are provided.

  In this case, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the opening command of the control valves 61A, 61B, 63A, and 63B. The predetermined relationship F4 with the operation command of the fan 52 is stored in advance in a storage device such as an internal HDD. This relationship F4 is a modification of the combination of the operation commands of the fans 52A to 52D shown in FIG. 10 described in the second embodiment. The other configurations of the fourth embodiment are the same as the configurations of the second embodiment, and the same or corresponding portions will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 14 shows temperature information of engine cooling water A, supercharger cooling water B, brake oil C, and air conditioner refrigerant D stored in the control device 71, opening commands for the control valves 61A, 61B, 63A, 63B, and fans. It is a figure which shows the relationship F4 with the operation command of 52. The shaded column in the figure shows the difference from the relationship F2 of FIG. 10 described in the second embodiment.

  In FIG. 14, when the temperature information of any one of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D becomes 1, the fan control unit 711 generates an operation command for the fan 52. Output. At this time, the fan control unit 711 controls the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A, the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B, and the brake. The rotation speed of the fan 52 is controlled according to the temperature TC of the brake oil C detected by the oil temperature sensor 72C and the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D. This makes it possible to adjust the amount (air amount) of the cooling airflows a to d generated by the fan 52.

  For example, the fan control unit 711 determines that the higher the temperatures TA to TD of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, that is, the larger the required heat exchange amount, the more the fan. The target value of the rotation speed of 52 is set high, and the lower the respective temperatures TA to TD of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, that is, the required heat exchange amount is The larger the value, the lower the target value of the rotation speed of the fan 52 is set, so that these refrigerants can be efficiently cooled. Even with the dump truck 1 according to the fourth embodiment of the present invention configured as described above, it is possible to obtain the same effects as those of the second embodiment described above.

  In the fourth embodiment of the present invention, the case where the fan 52 is rotated by the electric motor has been described, but the present invention is not limited to this case, and instead of the electric motor, the fan 52 is hydraulically operated. A rotating hydraulic motor may be used, or a drive shaft of the fan 52 and an output shaft of the engine 32 are connected by a belt (not shown) so that the fan 52 rotates together with the output shaft of the engine 32. May be. In the case of the latter configuration, the rotation speed of the fan 52 can be increased or decreased by changing the engagement amount of a clutch (not shown) interposed between the fan 52 and the belt.

[Fifth Embodiment]
The fifth embodiment of the present invention is different from the above-described first embodiment in that in the first embodiment, as shown in FIG. 4, the air conditioner condenser 56 allows the air flow d of the cooling air from the fan 52D to pass therethrough. While the air conditioner condenser 56 is arranged so as to face the lower side of the upstream radiator 54B, the air conditioner condenser 56 allows the cooling airflow a by the fan 52A to pass therethrough as shown in FIG. That is, it is arranged so as to face the upper side of the upstream radiator 54A.

  In this case, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the opening command of the control valves 61A, 61B, 63A, and 63B. A predetermined relationship F5 with the operation commands of the fans 52 to 52D is stored in advance in a storage device such as an internal HDD. This relationship F5 is obtained by partially changing the combination of the operation commands of the fans 52A to 52D shown in FIG. 6 described in the first embodiment. The other configurations of the fifth embodiment are the same as the configurations of the first embodiment, and the same or corresponding portions will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 16 shows temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D stored in the control device 71, the opening command of the control valves 61A, 61B, 63A, 63B, and the fan. It is a figure which shows the relationship F5 with the operation command of 52A-52D. The shaded column in the figure shows the difference from the relationship F1 of FIG. 6 described in the first embodiment.

  In FIG. 16, when the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D becomes equal to or higher than the predetermined temperature Td and the temperature information of the air conditioner refrigerant D becomes 1, the fan control unit 711 causes the fan 52A to operate. A command is generated and transmitted to the electric motor 59A (line 01). As a result, the electric motor 59A rotates the fan 52A in accordance with the operation command from the fan control unit 711, so that the cooling airflow a passing through the air conditioner condenser 56 is generated.

  According to the dump truck 1 according to the fifth embodiment of the present invention thus configured, the same operational effects as the above-described first embodiment can be obtained, and in addition, the line 03, line 04, line 07 shown in FIG. And the line 08, the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A is less than Ta3, or the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B. If the temperature TB is less than Tb3, the fan control unit 711 outputs the operation command of the fans 52A and 52B, and the operation commands of the fans 52C and 52D are not output. Therefore, the number of operated fans 52A to 52D is reduced, and the fan power can be reduced accordingly.

[Sixth Embodiment]
The sixth embodiment of the present invention is different from the above-described second embodiment in that a cooling device 51 according to the second embodiment includes four fans 52A to 52D that take in outside air into the inside to generate cooling air, and these. While the electric motors 59A to 59D for rotating the fans 52A to 52D are provided, as shown in FIGS. 17 and 18, the cooling device 51 according to the sixth embodiment is different from the fans 52A to 52D in FIG. Is also set to have a large outer diameter, and the fan 52E that generates the air flow e of the cooling air passing through the upstream radiators 54A and 54B and the downstream radiators 53A and 53B, and the cooling air passing through the brake oil cooler 55 and the air conditioner condenser 56 By providing the fans 52F and 52E that generate the airflows f and g, the clutch 81 that transmits the driving force of the engine 32 to the fan 52E, and the electric motors 59F and 59G that rotate the fans 52F and 52G. is there.

  In this case, a drive shaft 82 for driving the fan 52E extends from the engine 32, and the drive shaft 82 is connected to an output shaft 84 of the engine 32 via a belt 83. The clutch 81 is attached between the fan 52E and the drive shaft 82, and by changing the engagement amount of the clutch 81, the rotation speed of the fan 52E with respect to the rotation speed of the engine 32 can be adjusted. ..

  The fan 52F has a blade diameter smaller than that of the fan 52E, and is arranged behind the brake oil cooler 55 and in the vicinity of the fan 52E. Similarly, the fan 52G has a blade diameter smaller than that of the fan 52E, and is arranged behind the air conditioner condenser 56 and in the vicinity of the fan 52E. The electric motors 59F and 59G are attached to the rear sides of the fans 52F and 52G.

  Further, the electric motors 59F and 59G are electrically connected to the auxiliary inverter 38 and the control device 71, and operate or stop independently of each other in accordance with a control command from the control device 71, or the fans 52F and 52G. The rotation speed of can be adjusted. Note that, in FIG. 18, the brake oil cooler 55, the fan 52F, the electric motor 59F, and the air flow f of the cooling air are not shown as overlapping with the air conditioner condenser 56, the fan 52G, the electric motor 59G, and the air flow g of the cooling air. .

  Further, in the sixth embodiment of the present invention, the control device 71 controls the temperature information of the engine cooling water A, the supercharger cooling water B, the brake oil C, and the air conditioner refrigerant D, and the control valves 61A, 61B, 63A. , 63B and the fan 52 operation command are stored in advance in a storage device such as an internal HDD. This relationship F6 is a modification of the combination of the operation commands of the fans 52A to 52D shown in FIG. 10 described in the second embodiment. The other configurations of the sixth embodiment are the same as the configurations of the second embodiment, and the same or corresponding portions will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 19 shows temperature information of engine cooling water A, supercharger cooling water B, brake oil C, and air conditioner refrigerant D stored in the control device 71, opening commands for the control valves 61A, 61B, 63A, 63B, and fans. It is a figure which shows the relationship F6 with the operation command of 52E-52G. The shaded column in the figure shows the difference from the relationship F2 of FIG. 10 described in the second embodiment.

  In FIG. 19, when the temperature TD of the air conditioner refrigerant D detected by the air conditioner refrigerant temperature sensor 72D becomes equal to or higher than the predetermined temperature Td and the temperature information of the air conditioner refrigerant D becomes 1, the fan control unit 711 causes the fan 52G to operate. A command is generated and transmitted to the electric motor 59G (line 01). As a result, the electric motor 59G rotates the fan 52G in accordance with an operation command from the fan control unit 711, so that an air flow g of cooling air passing through the air conditioner condenser 56 is generated.

  When the temperature TC of the brake oil C detected by the brake oil temperature sensor 72C becomes equal to or higher than a predetermined temperature Tc and the temperature information of the brake oil C becomes 1, the fan control unit 711 generates an operation command for the fan 52F. It is transmitted to the electric motor 59F (line 02). As a result, the electric motor 59F rotates the fan 52F in accordance with the operation command from the fan control unit 711, so that an air flow f of cooling air passing through the brake oil cooler 55 is generated.

  On the other hand, when the temperature information of either the engine cooling water A or the supercharger cooling water B becomes 1, the fan control unit 711 generates an operation command for the fan 52E and outputs it to the clutch 81. At this time, the fan control unit 711 sets the temperature TA of the engine cooling water A detected by the engine cooling water temperature sensor 72A and the temperature TB of the supercharger cooling water B detected by the supercharger cooling water temperature sensor 72B. Accordingly, the engagement amount of the clutch 81 is changed to control the rotation speed of the fan 52E. Thereby, the amount of the cooling airflow e generated by the fan 52E can be adjusted.

  According to the dump truck 1 according to the sixth embodiment of the present invention configured as described above, in addition to the same operational effects as the above-described second embodiment, the following operational effects can be achieved. That is, in the sixth embodiment of the present invention, unlike the upstream radiators 54A and 54B or the downstream radiators 53A and 53B, the cooling airflow e that passes through a relatively large area is not required (that is, the cooling air The airflows f and g passing through the brake oil cooler 55 or the air conditioner condenser 56 (where the airflow passage area is relatively small) are generated by the fans 52F and 52G having relatively small power. Therefore, in a state where it is not necessary to cool the upstream radiators 54A and 54B and the downstream radiators 53A and 53B, the fan 52E can be stopped, and the fan power can be reduced accordingly.

[Seventh Embodiment]
The seventh embodiment of the present invention is different from the first embodiment described above. In the first embodiment, as shown in FIG. 3, the electric motors 59A to 59D are attached to the rear sides of the fans 52A to 52D. On the other hand, in the seventh embodiment, as shown in FIG. 20, the electric motors 59A to 59D are attached to the front sides of the fans 52A to 52D, the upstream radiators 54A and 54B, the downstream radiators 53A and 53B, and the fans. That is, it is housed in the casing 64 together with 52A to 52D. The other configurations of the seventh embodiment are the same as the configurations of the first embodiment, and the same or corresponding parts will be denoted by the same reference symbols and redundant description will be omitted.

  According to the dump truck 1 according to the seventh embodiment of the present invention configured as described above, in addition to the same operational effects as the above-described first embodiment, the fans 52A to 52D and the downstream radiators 53A and 53B are provided. Since the electric motors 59A to 59D are located in the space between the electric motors 59A to 59D, the electric motors 59A to 59D do not interfere with the engine 32 even if the space between the engine 32 and the fans 52A to 52D is narrow. The structure can be made compact.

  The above-described embodiments of the present invention have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.

11 ... Body frame, 17 ... Control cabinet, 18 ... Grid box, 19 ... Grill box, 20 ... Luggage platform 31 ... Drive circuit, 32 ... Engine, 33 ... Main generator, 34 ... Auxiliary generator, 35 ... Rectifier, 36 ... Capacitor, 37L, 37R ... Main inverter, 38 ... Auxiliary inverter, 39 ... Chopper, 42 ... Grid resistance, 43 ... Grid blower, 44 ... Auxiliary motor 51 ... Cooling device, 52, 52A to 52G ... Fan, 53A, 53B ... Downstream Side radiator (first heat exchanger), 54A, 54B ... Upstream radiator (second heat exchanger), 55 ... Brake oil cooler, 56 ... Air conditioner condenser, 57 ... First circulation circuit, 57A, 57B ... Pipe line, 58 ... 2nd circulation circuit, 58A, 58B ... Pipe line, 59A-59D, 59F, 59G ... Electric motor, 60 ... Thermostat, 61A, 61B ... Control valve (1st opening / closing valve), 62 ... Thermostat, 63A, 63B ... Control valve (second on-off valve), 64 ... Casing 71 ... Control device, 72A ... Engine cooling water temperature sensor (first refrigerant temperature detecting section), 72B ... Supercharger cooling water temperature sensor (second refrigerant temperature detecting section) , 72C ... Brake oil temperature sensor, 72D ... Air conditioner refrigerant temperature sensor 81 ... Clutch, 82 ... Drive shaft, 83 ... Belt, 84 ... Output shaft, 711 ... Fan control unit (fan drive unit), 712 ... Open / close control unit

Claims (6)

Engine,
At least one fan that takes in outside air to generate cooling air,
A plurality of first heat exchangers for exchanging heat between the cooling air and the first refrigerant flowing through a predetermined first portion in the engine;
A plurality of second heat exchangers arranged on the upstream side of the cooling airflow with respect to each of the plurality of first heat exchangers and performing heat exchange between the cooling medium and the second refrigerant flowing through the predetermined second portion in the engine. A second heat exchanger,
A first circulation circuit connected in parallel to each of the plurality of first heat exchangers, wherein the first refrigerant circulates between the engine and the plurality of first heat exchangers,
A second circulation circuit connected in parallel to each of the plurality of second heat exchangers, the second refrigerant circulating between the engine and the plurality of second heat exchangers;
A plurality of first on-off valves which are provided in the first circulation circuit and which connect or block the flow paths of the first refrigerant that respectively flow to the plurality of first heat exchangers;
A plurality of second on-off valves which are provided in the second circulation circuit and which communicate or block the flow paths of the second refrigerant flowing to the plurality of second heat exchangers,
A fan drive unit for driving the at least one fan;
The plurality of first on-off valves such that at least one of the first refrigerant and the second refrigerant passes through only a region where the at least one fan is driven by the fan driving unit and the airflow of the cooling air is generated. And a switching control unit that controls the switching operations of the plurality of second switching valves, respectively. The work machine according to claim 1,
A first refrigerant temperature detector for detecting the temperature of the first refrigerant;
A second refrigerant temperature detection unit that detects the temperature of the second refrigerant,
The opening / closing control unit is configured to, based on the temperature of the first refrigerant detected by the first refrigerant temperature detection unit and the temperature of the second refrigerant detected by the second refrigerant temperature detection unit, the plurality of first opening / closing units. A working machine, which controls an opening / closing valve and opening / closing operations of the plurality of second opening / closing valves, respectively. The work machine according to claim 1,
Said plurality of first on-off valve, respectively, wherein by opening and closing in accordance with a control command from the switching control unit, a first control valve for controlling the flow of the first refrigerant flowing into the plurality of first heat exchanger, respectively Consists of
Said plurality of second on-off valve, respectively, wherein by opening and closing in accordance with a control command from the switching control unit, a second control valve for controlling the flow of the second coolant flowing into the plurality of second heat exchanger, respectively A working machine characterized by being configured from. The work machine according to claim 1,
It said plurality of first opening and closing valve are respectively composed of a first thermostat which has a function to open and close in response to the temperature of the first refrigerant flowing into the respective front Symbol plurality of first heat exchanger,
It said plurality of second on-off valve, respectively, characterized in that it consists of second thermostat having the function to open and close in response to the temperature of the second coolant flowing into the respective front Symbol plurality of second heat exchanger Work machine. The work machine according to claim 1,
The plurality of first heat exchangers are arranged adjacent to each other in a direction traversing the cooling air, and a pair of downstream sides that perform heat exchange between the engine cooling water flowing through the cylinder side of the engine and the cooling air. It consists of a radiator,
The plurality of second heat exchangers are arranged adjacent to each other in a direction traversing the cooling air, and perform heat exchange between the cooling air and the supercharger cooling water flowing on the supercharger side of the engine. It consists of a pair of upstream radiators,
The at least one fan is arranged so as to face the pair of downstream radiators and sandwich the pair of downstream radiators with the pair of upstream radiators, and sucks the outside air to cool the cooling air. A working machine characterized by comprising a plurality of intake fans that generate the air flow of. An engine, at least one fan that takes in outside air to generate cooling air, and a plurality of first heats that perform heat exchange between the cooling air and the first refrigerant that has flowed through a predetermined first portion in the engine. The heat exchange between the cooling air and the second refrigerant that is arranged upstream of the air flow of the cooling air with respect to each of the exchanger and the plurality of first heat exchangers and that has flowed through a predetermined second portion in the engine. a plurality of second heat exchanger to perform, is connected in parallel to the first heat exchanger wherein each of the plurality of first said first refrigerant circulates between said engine and said plurality of first heat exchanger, respectively 1 a circulation circuit, is connected in parallel to the plurality of second heat exchanger, a second circulation circuit, wherein the second refrigerant circulates between each of said engine and said plurality of second heat exchanger, wherein A plurality of first opening / closing valves provided in the first circulation circuit and communicating or blocking the flow paths of the first refrigerant flowing to the plurality of first heat exchangers, and the second circulation circuit, The present invention is applied to a working machine including a plurality of second on-off valves that connect or block the flow paths of the second refrigerant that respectively flow to a plurality of second heat exchangers,
Cooling of the work machine for controlling the cooling of the second refrigerant in at least one of the first refrigerant and the plurality of second heat exchanger each inner portion of the inner portion of the plurality of first heat exchanger, respectively by a fan A control method,
A fan driving step for driving the at least one fan;
The plurality of first on-off valves such that at least one of the first refrigerant and the second refrigerant passes only through a region where the cooling airflow is generated by driving the at least one fan in the fan driving step. And an opening / closing control step for controlling opening / closing operations of the plurality of second opening / closing valves, respectively.