Construction machine

Abstract

To provide a construction machine capable of improving water consumption created by fuel cells.SOLUTION: A shovel is provided with: fuel cells 29; electrical equipment 34 to which power created by the fuel cells 29 is supplied; hydraulic equipment 33 driven using the electrical equipment 34; an air-cooled cooler 35A cooling coolant for the fuel cells 29; an air-cooler 35B cooling hydraulic oil of the hydraulic equipment 33; a water spray device 38A spraying water created by the fuel cells 29 to the cooler 35A; and a spray device 38B spraying water created by the fuels cells 29 to the cooler 35B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a construction machine equipped with a fuel cell. [Background technology]

[0002] Patent Document 1 discloses that a general vehicle such as an automobile is equipped with a fuel cell that generates electricity and water by chemically reacting hydrogen and oxygen, a traction motor that is driven by the electricity generated by the fuel cell, an air-cooled heat exchanger that cools the cooling water for the fuel cell, a tank that stores the water generated by the fuel cell, and a water spray device that sprays the water stored in the tank onto the heat exchanger.

[0003] The heat exchanger not only exchanges heat with the air drawn in by the fan, but also cools the cooling water by evaporating water sprayed by a water spray device. This consumes the water produced in the fuel cell and increases the cooling power of the heat exchanger. The fan is located on the back side of the heat exchanger, and the water spray device is located on the front side of the heat exchanger (i.e., the side opposite the back side).

[0004] From the perspective of decarbonization, the installation of fuel cells in construction machinery such as excavators is also being considered. If the technology described in Patent Document 1 is adopted for construction machinery equipped with fuel cells, it will be possible to consume the water produced by the fuel cells. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6500790 Summary of the Invention [Problem to be solved by the invention]

[0006] However, construction machinery consumes more electricity than ordinary vehicles such as automobiles, and therefore generates large amounts of water in fuel cells, leaving room for improvement in terms of the large amount of water consumed.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a construction machine that can increase the consumption of water produced by a fuel cell. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a construction machine comprising a fuel cell, electrical equipment supplied with power generated by the fuel cell, hydraulic equipment driven using the electrical equipment, an air-cooled first cooler that cools the cooling water for the fuel cell, and an air-cooled second cooler that cools the hydraulic oil of the hydraulic equipment, and further comprising a first sprinkler device that sprays water generated by the fuel cell onto the first cooler, and a second sprinkler device that sprays water generated by the fuel cell onto the second cooler. [Effects of the Invention]

[0009] According to the present invention, the consumption of water produced in the fuel cell can be increased. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view showing the structure of a shovel in one embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating a configuration of a drive system according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram illustrating a configuration of a cooling system according to an embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram showing the functional configuration of a controller together with related devices in an embodiment of the present invention. [Figure 5] 4 is a flowchart showing a processing procedure of a controller in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described with reference to the drawings.

[0012] FIG. 1 is a side view showing the structure of a shovel in this embodiment.

[0013] The excavator of this embodiment includes a running body 1 and a revolving body 2 provided rotatably above the running body 1. The running body 1 travels by being driven by a traveling motor (not shown). The revolving body 2 revolves by being driven by a swing motor (not shown).

[0014] A working device 3 is connected to the front side (right side in FIG. 1 ) of the rotating unit 2. The working device 3 includes a boom 4 rotatably connected to the rotating unit 2, an arm 5 rotatably connected to the tip of the boom 4, and a bucket 6 rotatably connected to the tip of the arm 5. The boom 4 rotates when driven by a boom cylinder 7, the arm 5 rotates when driven by an arm cylinder 8, and the bucket 6 rotates when driven by a bucket cylinder 9.

[0015] The revolving body 2 comprises a revolving frame 10 that forms the base structure, a cab 11 in which the driver sits that is provided in front of the revolving frame 10 (right side in Figure 1), a counterweight 12 that is provided in the rear of the revolving frame 10 (left side in Figure 1), and a machine room 14 that is provided between the cab 11 and the counterweight 12 and that houses equipment such as an electric motor 13 (see Figures 2 and 3 described below).

[0016] The operator's cab 11 is provided with a travel operation device (not shown) that instructs the travel of the travelling body 1, a work operation device (not shown) that instructs the rotation of the boom 4 and the rotation of the bucket 6, a work operation device 15 (see Figure 2 described later) that instructs the rotation of the revolving body 2 and the rotation of the arm 5, a lock lever device 16 (see Figure 2 described later) that instructs switching between a locked state that prohibits the operation of the shovel and an unlocked state that allows the operation of the shovel, and a rotation speed dial 17 (see Figure 2 described later) that sets the rotation speed of the electric motor 13.

[0017] A monitor 18 (see FIG. 3 described later) is provided in the driver's cab 11. The monitor 18 has, for example, buttons that can be operated by the driver, a display that can be seen by the driver, and a processor that displays the display and performs various settings in response to button operations.

[0018] Next, a drive system that drives the multiple hydraulic actuators (more specifically, the above-mentioned travel motor, swing motor, boom cylinder 7, arm cylinder 8, and bucket cylinder 9) will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing the configuration of the drive system in this embodiment. For convenience, FIG. 2 shows only the configuration related to the drive of the arm cylinder 8 out of the multiple hydraulic actuators.

[0019] The drive system of this embodiment includes an electric motor 13, an inverter 19 that controls the rotation speed of the electric motor 13, a variable displacement hydraulic pump 20 driven by the electric motor 13, a regulator 21 that adjusts the capacity of the hydraulic pump 20 (for example, the tilt angle of the swash plate), and a control valve 22 that controls the flow of pressurized oil from the hydraulic pump 20 to the arm cylinder 8 (more specifically, the direction and flow rate).

[0020] The drive system of this embodiment includes a pilot pump 23 driven by an electric motor 13, a pilot relief valve 24 that determines the discharge pressure of the pilot pump 23, electromagnetic proportional valves 25A, 25B that generate pilot pressure using the discharge pressure of the pilot pump 23 as a source pressure and output the generated pilot pressure to the pressure-receiving portion of the control valve 22, a lock valve 26 (lock device) provided between the pilot pump 23 and the electromagnetic proportional valves 25A, 25B, etc., and a controller 27.

[0021] The work operation device 15 includes an operation lever (operation member) that can be operated by the driver, a first potentiometer that generates and outputs a first operation signal according to the amount of operation of one side of the operation lever, and a second potentiometer that generates and outputs a second operation signal according to the amount of operation of the other side of the operation lever.

[0022] The controller 27 has a processor that executes processing according to a program, and a memory that stores the program and data. The controller 27 generates a drive signal in response to a first operation signal from the work operation device 15, and outputs the drive signal to the solenoid proportional valve 25A. The solenoid proportional valve 25A generates a pilot pressure corresponding to the drive signal, and outputs the pilot pressure to a pressure receiving portion on one side of the control valve 22. As a result, the control valve 22 is switched to the switching position on the right side in the figure, and pressure oil from the hydraulic pump 20 is supplied to the upper rod chamber in the figure of the arm cylinder 8 via the control valve 22, causing the arm cylinder 8 to retract and contract.

[0023] The controller 27 generates a drive signal in response to a second operation signal from the work operation device 15 and outputs it to the electromagnetic proportional valve 25B. The electromagnetic proportional valve 25B generates a pilot pressure corresponding to the drive signal and outputs it to the pressure receiving portion on the other side of the control valve 22. As a result, the control valve 22 is switched to the switching position on the left side in the figure, and pressure oil from the hydraulic pump 20 is supplied to the bottom chamber on the lower side in the figure of the arm cylinder 8 via the control valve 22, causing the arm cylinder 8 to extend.

[0024] The configurations related to the drive of the other hydraulic actuators (more specifically, the travel motor, the swing motor, the boom cylinder 7, or the bucket cylinder 9) are substantially the same as the configuration related to the drive of the arm cylinder 8. That is, the controller 27 generates a drive signal in response to an operation signal from a potentiometer of the corresponding operating device, and outputs the drive signal to the corresponding electromagnetic proportional valve. The corresponding control valve is switched by the pilot pressure generated by the electromagnetic proportional valve, and pressure oil discharged from the hydraulic pump is supplied to the other hydraulic actuators, thereby driving the other hydraulic actuators. A lock valve 26 is provided between all the electromagnetic proportional valves, including the electromagnetic proportional valves 25A and 25B, and the pilot pump 23.

[0025] The lock lever device 16 includes a lock lever that can be operated to a locked position (raised position) and an unlocked position (lowered position), and a lock switch that does not output a signal when the lock lever is operated to the locked position and outputs a signal when the lock lever is operated to the unlocked position.

[0026] When no signal is input from the lock lever device 16, the controller 27 does not output a drive signal to the lock valve 26. This causes the lock valve 26 to be in the shutoff position on the right side in the figure, and the discharge pressure of the pilot pump 23 is not introduced to any of the electromagnetic proportional valves. Therefore, a locked state is established in which the drive of all hydraulic actuators, i.e., the operation of the excavator, is prohibited.

[0027] When a signal is input from the lock lever device 16, the controller 27 outputs a drive signal to the lock valve 26. This causes the lock valve 26 to move to the communicating position on the left side in the figure, and the discharge pressure of the pilot pump 23 is introduced to all the electromagnetic proportional valves. Therefore, the controller 27 enters an unlocked state which allows the drive of all the hydraulic actuators, i.e., the operation of the excavator.

[0028] The controller 27 controls the inverter 19 so that the rotation speed of the electric motor 13 becomes the rotation speed set by the rotation speed dial 17. The controller 27 controls the regulator 21 to adjust the capacity of the hydraulic pump 20 based on the rotation speed of the electric motor 13 set by the rotation speed dial 17 and the maximum value of the operation amounts of the travel operation device, the work operation device, and the work operation device 15.

[0029] The drive system of this embodiment includes a high-voltage circuit 28 that supplies power to the inverter 19, a fuel cell 29 that generates power and water by chemically reacting hydrogen and oxygen, a boost converter 30 that connects the fuel cell 29 to the high-voltage circuit 28, a secondary battery 31 that can be charged and discharged, and a bidirectional converter 32 that connects the secondary battery 31 to the high-voltage circuit 28.

[0030] The boost converter 30 boosts the power generated by the fuel cell 29 and supplies it to the high-voltage circuit 28. When the power of the high-voltage circuit 28 is in excess of the power consumed by the electric motor 13, the bidirectional converter 32 reduces the power of the high-voltage circuit 28 and supplies it to the secondary battery 31, thereby charging the secondary battery 31. When the power of the high-voltage circuit 28 is insufficient compared to the power consumed by the electric motor 13, the bidirectional converter 32 boosts the power discharged from the secondary battery 31 and supplies it to the high-voltage circuit 28.

[0031] Next, a cooling system that cools the cooling water for the fuel cell 29, the hydraulic oil for the hydraulic equipment 33, and the cooling water for the electrical equipment 34 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing the configuration of the cooling system in this embodiment. The electrical equipment 34 is supplied with electric power generated by the fuel cell 29, and is, for example, the electric motor 13 and a secondary battery 31. The hydraulic equipment 33 is driven by the electrical equipment 34, and is, for example, the hydraulic pump 20.

[0032] The cooling system of this embodiment includes an air-cooled cooler 35A that cools the cooling water circulating between the fuel cell 29, an air-cooled cooler 35B that cools the hydraulic oil circulating between the hydraulic equipment 33, an air-cooled cooler 35C that cools the cooling water circulating between the hydraulic equipment 33, a water tank 36 that stores water produced by the fuel cell 29, a sprinkler device 38A that sprays water supplied from the water tank 36 via a water pump 37 to the cooler 35A, a sprinkler device 38B that sprays water supplied from the water tank 36 via the water pump 37 to the cooler 35B, a sprinkler device 38C that sprays water supplied from the water tank 36 via the water pump 37 to the cooler 35C, a cooling fan 39A that generates cooling air flowing toward the cooler 35A, a cooling fan 39B that generates cooling air flowing toward the cooler 35B, and a cooling fan 39C that generates cooling air flowing toward the cooler 35C. A drain valve (not shown) that allows water to be discharged is provided at the bottom of the water tank .

[0033] The cooler 35A cools the cooling water for the fuel cell 29 by heat exchange with air supplied from a cooling fan 39A and by evaporation of water sprayed by a sprinkler system 38A. The sprinkler system 38A is arranged so that the cooling fan 39A is interposed between the cooler 35A and the cooler 35A (in other words, the cooling fan 39A is arranged between the sprinkler system 38A and the cooler 35A). This allows the water sprayed by the sprinkler system 38A to collide with the cooling fan 39A and break down into fine particles, thereby increasing the cooling power of the cooler 35A. The sprinkler system 38A can vary the amount of water sprayed by changing the aperture opening.

[0034] The cooler 35B cools the hydraulic oil of the hydraulic equipment 33 by heat exchange with air supplied from the cooling fan 39B and by evaporation of water sprayed by the sprinkler system 38B. The sprinkler system 38B is arranged so that the cooling fan 39B is interposed between the cooler 35B and the sprinkler system 38B (in other words, the cooling fan 39B is arranged between the sprinkler system 38B and the cooler 35B). This allows the water sprayed by the sprinkler system 38B to collide with the cooling fan 39B and break down into fine particles, thereby increasing the cooling power of the cooler 35B. The sprinkler system 38B can vary the amount of water sprayed by changing the aperture opening.

[0035] Cooler 35C cools the cooling water for electrical equipment 34 by heat exchange with air supplied from cooling fan 39C and by evaporation of water sprayed by sprinkler system 38C. Sprinkler system 38C is arranged so that cooling fan 39C is interposed between cooler 35C and sprinkler system 38C (in other words, cooling fan 39C is arranged between sprinkler system 38C and cooler 35C). This allows the water sprayed by sprinkler system 38C to collide with cooling fan 39C and break down into fine particles, thereby increasing the cooling power of cooler 35C. Note that sprinkler system 38C can vary the amount of water sprayed by changing the aperture opening.

[0036] The cooling system of this embodiment includes a temperature sensor 40A that detects the temperature of the cooling water for the fuel cell 29, a temperature sensor 40B that detects the temperature of the hydraulic oil for the hydraulic equipment 33, a temperature sensor 40C that detects the temperature of the cooling water for the electrical equipment 34, and a water volume sensor 41 that detects the amount of water stored in the water tank 36.

[0037] Based on the detection results of the temperature sensor 40A and the water volume sensor 41, the controller 27 controls the amount of water sprayed by the sprinkler device 38A and the rotation speed of the cooling fan 39A to control the cooling power of the cooler 35A. Based on the detection results of the temperature sensor 40B and the water volume sensor 41, the controller 27 controls the amount of water sprayed by the sprinkler device 38B and the rotation speed of the cooling fan 39B to control the cooling power of the cooler 35B. Based on the detection results of the temperature sensor 40C and the water volume sensor 41, the controller 27 controls the amount of water sprayed by the sprinkler device 38C and the rotation speed of the cooling fan 39C to control the cooling power of the cooler 35C. This allows appropriate temperature management for the coolers 35A, 35B, and 35C, each of which has a different appropriate temperature range. The functional configuration of the controller 27 related to the above-described control will be described with reference to FIG. 4. FIG. 4 is a block diagram showing the functional configuration of the controller 27 in this embodiment, along with related devices.

[0038] The controller 27 has functional configurations including a subtraction unit 42, a water spray amount calculation unit 43, a rotation speed calculation unit 44, a first coefficient calculation unit 45, a second coefficient calculation unit 46, multiplication units 47A, 47B, a water spray amount control unit 48, and a rotation speed control unit 49.

[0039] The controller 27 stops the rotation of the cooling fan 39A when the temperature of the cooling water for the fuel cell 29 detected by the temperature sensor 40A is lower than a preset target temperature. On the other hand, when the temperature of the cooling water for the fuel cell 29 detected by the temperature sensor 40A is higher than the target temperature, the controller 27 rotates the cooling fan 39A. In this case, the subtraction unit 42 subtracts the target temperature from the temperature of the cooling water for the fuel cell 29 detected by the temperature sensor 40A to calculate the temperature difference of the cooling water for the fuel cell 29. The water sprinkling amount calculation unit 43 calculates the amount of water sprinkled by the sprinkler 38A so that it is proportional to the temperature difference of the cooling water for the fuel cell 29. In other words, the higher the temperature of the cooling water for the fuel cell 29 detected by the temperature sensor 40A is, the higher the water sprinkling amount of the water sprinkler 38A increases. The rotation speed calculation unit 44 calculates the rotation speed of the cooling fan 39A so that it is proportional to the temperature difference of the cooling water for the fuel cell 29. That is, the higher the temperature of the cooling water for the fuel cell 29 detected by the temperature sensor 40A is, the higher the rotation speed of the cooling fan 39A is.

[0040] First coefficient calculation unit 45 calculates first coefficient A (for example, 1≧A≧0) so that the first coefficient A is proportional to the amount of water in water tank 36 detected by water volume sensor 41. Multiplication unit 47A corrects the amount of water sprinkled by sprinkler device 38A by multiplying the amount of water sprinkled by sprinkler device 38A calculated by water sprinkler volume calculation unit 43 by first coefficient A. In other words, the greater the amount of water in water tank 36 detected by water volume sensor 41, the more the amount of water sprinkled by sprinkler device 38A increases. Water sprinkler volume control unit 48 controls the throttle opening of sprinkler device 38A according to the amount of water sprinkled by sprinkler device 38A corrected by multiplication unit 47A.

[0041] Second coefficient calculation unit 46 calculates second coefficient B (for example, B=1-A) so that the second coefficient B decreases as first coefficient A increases. Multiplication unit 47B corrects the rotation speed of cooling fan 39A by multiplying the rotation speed of cooling fan 39A calculated by rotation speed calculation unit 44 by second coefficient B. In other words, the greater the amount of water in water tank 36 detected by water volume sensor 41, the more the rotation speed of cooling fan 39A decreases. Rotation speed control unit 49 controls cooling fan 39A in accordance with the rotation speed of cooling fan 39A corrected by multiplication unit 47B.

[0042] The controller 27 stops the rotation of the cooling fan 39B when the temperature of the hydraulic oil of the hydraulic equipment 33 detected by the temperature sensor 40B is lower than a preset target temperature. On the other hand, when the temperature of the hydraulic oil of the hydraulic equipment 33 detected by the temperature sensor 40B is higher than the target temperature, the controller 27 rotates the cooling fan 39B. In this case, the subtraction unit 42 subtracts the target temperature from the temperature of the hydraulic oil of the hydraulic equipment 33 detected by the temperature sensor 40B to calculate the temperature difference of the hydraulic oil of the hydraulic equipment 33. The water sprinkling amount calculation unit 43 calculates the amount of water sprinkled by the sprinkler 38B so that it is proportional to the temperature difference of the hydraulic oil of the hydraulic equipment 33. In other words, the higher the temperature of the hydraulic oil of the hydraulic equipment 33 detected by the temperature sensor 40B is, the higher the amount of water sprinkled by the sprinkler 38B becomes. The rotation speed calculation unit 44 calculates the rotation speed of the cooling fan 39B so that it is proportional to the temperature difference of the hydraulic oil of the hydraulic equipment 33. That is, the rotation speed of the cooling fan 39B is increased as the temperature of the hydraulic oil in the hydraulic device 33 detected by the temperature sensor 40B becomes higher than the target temperature.

[0043] Multiplication unit 47A corrects the amount of water sprinkled by sprinkler device 38B by multiplying the amount of water sprinkled by sprinkler device 38B calculated by sprinkler rate calculation unit 43 by first coefficient A. In other words, the greater the amount of water in water tank 36 detected by water rate sensor 41, the more water sprinkled by sprinkler device 38B is increased. Sprinkler rate control unit 48 controls the throttle opening of sprinkler device 38B in accordance with the amount of water sprinkled by sprinkler device 38B corrected by multiplication unit 47A.

[0044] Multiplication unit 47B corrects the rotation speed of cooling fan 39B by multiplying the rotation speed of cooling fan 39B calculated by rotation speed calculation unit 44 by second coefficient B. In other words, the greater the amount of water in water tank 36 detected by water level sensor 41, the more the rotation speed of cooling fan 39B is reduced. Rotation speed control unit 49 controls cooling fan 39B in accordance with the rotation speed of cooling fan 39B corrected by multiplication unit 47B.

[0045] The controller 27 stops the rotation of the cooling fan 39C when the temperature of the cooling water for the electrical equipment 34 detected by the temperature sensor 40C is lower than a preset target temperature. On the other hand, when the temperature of the cooling water for the electrical equipment 34 detected by the temperature sensor 40C is higher than the target temperature, the controller 27 causes the rotation of the cooling fan 39C. In this case, the subtraction unit 42 subtracts the target temperature from the temperature of the cooling water for the electrical equipment 34 detected by the temperature sensor 40C to calculate the temperature difference of the cooling water for the electrical equipment 34. The water spray amount calculation unit 43 calculates the amount of water sprayed by the sprinkler 38C so that it is proportional to the temperature difference of the cooling water for the electrical equipment 34. In other words, the higher the temperature of the cooling water for the electrical equipment 34 detected by the temperature sensor 40C is, the more the amount of water sprayed by the sprinkler 38C increases. The rotation speed calculation unit 44 calculates the rotation speed of the cooling fan 39C so that it is proportional to the temperature difference of the cooling water for the electrical equipment 34. That is, the rotation speed of the cooling fan 39C is increased as the temperature of the cooling water for the electric device 34 detected by the temperature sensor 40C becomes higher than the target temperature.

[0046] Multiplication unit 47A corrects the amount of water sprinkled by sprinkler device 38C by multiplying the amount of water sprinkled by sprinkler device 38C calculated by sprinkler rate calculation unit 43 by first coefficient A. In other words, the greater the amount of water in water tank 36 detected by water rate sensor 41, the more water sprinkled by sprinkler device 38C is increased. Sprinkler rate control unit 48 controls the throttle opening of sprinkler device 38C in accordance with the amount of water sprinkled by sprinkler device 38C corrected by multiplication unit 47A.

[0047] Multiplication unit 47B corrects the rotation speed of cooling fan 39C by multiplying the rotation speed of cooling fan 39C calculated by rotation speed calculation unit 44 by second coefficient B. In other words, the greater the amount of water in water tank 36 detected by water level sensor 41, the more the rotation speed of cooling fan 39C is reduced. Rotation speed control unit 49 controls cooling fan 39B in accordance with the rotation speed of cooling fan 39C corrected by multiplication unit 47B.

[0048] The controller 27 controls the fuel cell 29 and the monitor 18 based on the detection result of the water volume sensor 41. The processing procedure of the controller 27 related to this control will be explained using Fig. 5. Fig. 5 is a flowchart showing the processing procedure of the controller 27 in this embodiment.

[0049] In step S1, the controller 27 determines whether the amount of water in the water tank 36 exceeds a threshold C (for example, 70% of the capacity of the water tank 36) based on the detection result of the water volume sensor 41. If the amount of water in the water tank 36 exceeds the threshold C, the process proceeds to step S2.

[0050] In step S2, the controller 27 determines whether the amount of water in the water tank 36 is less than threshold value D (e.g., 100% of the capacity of the water tank 36) based on the detection result of the water level sensor 41. If the amount of water in the water tank 36 exceeds threshold value C and is less than threshold value D, the process proceeds to steps S3 and S4. In step S3, the controller 27 limits the power generation of the fuel cell 29 to reduce the amount of water produced. The limit on the power generation of the fuel cell 29 may be variable or fixed depending on the amount of water in the water tank 36. In step S4, the controller 27 displays a warning message on the monitor 18 indicating that the amount of water in the water tank exceeds threshold value C and is less than threshold value D and the power generation of the fuel cell will be limited. This prompts the operator to drain water from the water tank 36 into a portable container, a drainage ditch, or the like. Therefore, if an appropriate drainage location such as a drainage ditch has been set up within the work site, the operator can drive the excavator to the drainage location and discharge the water stored in the water tank 36 into the drainage location.

[0051] If the amount of water in the water tank 36 reaches threshold D, the process proceeds to steps S5 and S6. In step S5, the controller 27 stops power generation in the fuel cell 29, thereby stopping water production. In step S6, the controller 27 displays a warning message on the monitor 18 indicating that the amount of water in the water tank has reached threshold D and that the fuel cell will be stopped. This notifies the operator that the shovel can be operated using only the power stored in the secondary battery 31. The controller also urges the operator to drain the water from the water tank 36 into a portable container, a drain, or the like.

[0052] The shovel of this embodiment described above is provided with a water tank 36 that stores water produced by the fuel cell 29 and sprinkler devices 38A, 38B, and 38C that spray water stored in the water tank 36 to the coolers 35A, 35B, and 35C, respectively, thereby increasing the consumption of water produced by the fuel cell 29. Furthermore, unlike ordinary vehicles such as automobiles, shovels often stay in the same location for long periods of time to perform excavation work. If water is discharged onto the ground around the shovel while the shovel is operating, the ground may become muddy and become unstable if the ground is soil. The shovel of this embodiment displays a caution or warning message depending on the amount of water in the water tank 36, thereby urging the driver to drain water from the water tank 36 into a portable container, a drain, or the like. As a result, it is possible to prevent the ground from becoming unstable due to water being discharged onto the work site of the shovel.

[0053] Although not specifically described in the above embodiment, the monitor 18 may be able to select either an output priority mode or an operating time priority mode. When the operating time priority mode is selected by the monitor 18 and the amount of water in the water tank 36 exceeds the threshold C, the controller 27 may control the displacement of the hydraulic pump 20 and the rotation speed of the electric motor 13 so as to limit the horsepower of the hydraulic pump 20. The amount of limit on the horsepower of the hydraulic pump 20 may be variable depending on the amount of water in the water tank 36, or may be fixed.

[0054] In the above embodiment, the alarm that notifies the detection result of the water level sensor 41 is the monitor 18, and a case has been described in which a caution message or a warning message is displayed depending on the water level in the water tank 36. However, this is not limiting. The monitor 18 may also display the water level in the water tank 36. The alarm may be, for example, a buzzer that sounds depending on the water level in the water tank 36.

[0055] In the above embodiment, the sprinkler devices 38A, 38B, and 38C are arranged such that a cooling fan is interposed between them and the coolers, but this is not limiting. That is, the sprinkler devices 38A, 38B, and 38C may be arranged such that a cooling fan is not interposed between them and the coolers, although this does not provide the effect of atomizing the sprinkled water. Furthermore, for example, a single cooling fan may be arranged so that it is shared by the coolers 35A, 35B, and 35C.

[0056] Furthermore, in the above embodiment, the shovel has been described as being equipped with an air-cooled cooler 35C that cools the cooling water for the electrical equipment 34 and a sprinkler device 38C that sprinkles water stored in the water tank 36 onto the cooler 35C, but this is not limiting. That is, the shovel does not necessarily have to be equipped with the cooler 35C and the sprinkler device 38C, although this would reduce the effect of increasing water consumption.

[0057] Although the above description has been given taking a shovel as an example of an application of the present invention, the present invention is not limited to this. That is, the present invention may be applied to construction machines other than shovels. [Explanation of symbols]

[0058] 18 Monitor (alarm) 27 Controller 29 Fuel Cell 33 Hydraulic Equipment 34 Electrical Equipment 35A cooler (1st cooler) 35B Cooler (2nd cooler) 35C cooler (third cooler) 36 Water Tank 38A Sprinkler system (first sprinkler system) 38B Sprinkler system (second sprinkler system) 38C Sprinkler system (third sprinkler system) 39A Cooling fan (1st cooling fan) 39B Cooling fan (second cooling fan) 39C Cooling fan (third cooling fan) 40A Temperature Sensor (1st Temperature Sensor) 40B Temperature sensor (second temperature sensor) 40C temperature sensor (third temperature sensor) 41 Water volume sensor

Claims

1. A fuel cell; an electrical device supplied with the power generated by the fuel cell; a hydraulic device driven by the electric device; an air-cooled first cooler that cools the cooling water for the fuel cell; a second air-cooled cooler for cooling the hydraulic oil of the hydraulic equipment, a first water sprinkler that sprinkles water produced by the fuel cell onto the first cooler; a second sprinkler device that sprinkles water produced by the fuel cell onto the second cooler.

2. The construction machine according to claim 1, an air-cooled third cooler that cools the cooling water for the electrical equipment; a third sprinkler device that sprinkles water produced by the fuel cell onto the third cooler.

3. The construction machine according to claim 2, a first cooling fan that generates cooling air flowing toward the first cooler; a second cooling fan that generates cooling air flowing toward the second cooler; a third cooling fan that generates cooling air flowing toward the third cooler, the first cooling fan is disposed between the first sprinkler device and the first cooler, the second cooling fan is disposed between the second sprinkler device and the second cooler, A construction machine characterized in that the third cooling fan is disposed between the third sprinkler device and the third cooler.

4. The construction machine according to claim 1, a water tank that stores water generated by the fuel cell and sprayed by the first sprinkler device and the second sprinkler device; a water volume sensor that detects the amount of water stored in the water tank; and an alarm that notifies the detection result of the water volume sensor.

5. The construction machine according to claim 1, a water tank that stores water generated by the fuel cell and sprayed by the first sprinkler device and the second sprinkler device; a water volume sensor that detects the amount of water stored in the water tank; a first cooling fan that generates cooling air for the first cooler; a second cooling fan that generates cooling air for the second cooler; a first temperature sensor for detecting the temperature of the cooling water for the fuel cell; a second temperature sensor for detecting the temperature of the hydraulic oil of the hydraulic device; a controller that controls the amount of water sprayed by the first sprinkler device and the rotation speed of the first cooling fan based on the detection results of the first temperature sensor and the water volume sensor, and that controls the amount of water sprayed by the second sprinkler device and the rotation speed of the second cooling fan based on the detection results of the second temperature sensor and the water volume sensor.

6. The construction machine according to claim 5, The controller The higher the temperature detected by the first temperature sensor is, the higher the predetermined target temperature is, the more the amount of water sprayed by the first sprinkler device is increased and the rotation speed of the first cooling fan is increased; the higher the amount of water detected by the water volume sensor is, the more the amount of water sprayed by the first sprinkler device is increased and the rotation speed of the first cooling fan is decreased; A construction machine characterized in that the higher the temperature detected by the second temperature sensor is at a predetermined target temperature, the more the amount of water sprayed by the second sprinkler device is increased and the rotation speed of the second cooling fan is increased, and the greater the amount of water detected by the water volume sensor is, the more the amount of water sprayed by the second sprinkler device is increased and the rotation speed of the second cooling fan is decreased.

7. The construction machine according to claim 4, a controller that controls the fuel cell and the alarm based on the detection result of the water amount sensor; The controller When the amount of water detected by the water amount sensor exceeds a first threshold value and is less than a second threshold value, the power generated by the fuel cell is limited, and a warning message to the effect that the power generated by the fuel cell is limited is displayed by the alarm; A construction machine characterized in that, when the amount of water detected by the water volume sensor reaches the second threshold, power generation by the fuel cell is stopped and a warning message indicating that the fuel cell will be stopped is displayed by the alarm.

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