Work vehicle

Abstract

This work vehicle is equipped with a drive source which uses hydrogen as a fuel. The work vehicle comprises an electrolysis device for electrolyzing: generated water generated from the drive device by using power; or stored water that is stored in a water tank.

Description

Work vehicles

[0001] The present invention relates to a work vehicle. The present invention claims priority to Japanese Patent Application No. 2023-006101, filed on January 18, 2023, the contents of which are incorporated herein by reference.

[0002] Toward carbon neutrality, it is urgent to achieve zero emissions for mining machinery, construction machinery, and the like. One means for achieving zero emissions is fuel cell systems and hydrogen engines. For example, a fuel cell system includes a fuel cell (FC), a battery, and a hydrogen tank for storing hydrogen as fuel. For example, a fuel cell system is installed in a fuel cell vehicle (FCV) that runs on a traction motor. For example, the electric power charged in the battery is used as driving energy when the fuel cell vehicle is powered. For example, the regenerative power generated by the traction motor when the fuel cell vehicle is going downhill or decelerating is charged to the battery. However, the amount of power that can be charged to the battery is limited by the battery's capacity. Therefore, any power that cannot be fully charged in the battery is lost as heat energy, etc. Furthermore, in the case of a hydrogen engine vehicle that does not have a battery, all of the generated energy is lost. Therefore, it is necessary to reduce energy loss.

[0003] For example, Patent Document 1 discloses a fuel cell system that includes a water condensing means that condenses moisture in the air to produce water, a filtering means that filters the produced water, a fuel cell that uses the filtered water, and a control means that operates the water condensing means using surplus power from the fuel cell. The fuel cell system is installed in a fuel cell electric vehicle (FCEV).

[0004] Japanese Patent Application Publication No. 2004-206928

[0005] However, the filtered water is only used to humidify the electrolyte membrane of the fuel cell, and is not used as a driving energy source for the FCEV, so there is room for improvement in reducing energy loss.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a work vehicle that can reduce energy loss.

[0007] A work vehicle according to one aspect of the present invention is a work vehicle equipped with a drive source that uses hydrogen as fuel, and is equipped with an electrolysis device that uses electric power to electrolyze water generated from the drive source or water stored in a water tank.

[0008] According to the above aspect, it is possible to suppress energy loss.

[0009] A side view of a dump truck according to an embodiment. A block diagram of a circuit configuration of a fuel cell system according to an embodiment. An explanatory diagram of the flow of electricity and the like during traveling in a fuel cell system according to an embodiment. An explanatory diagram of the flow of electricity and the like during regeneration in a fuel cell system according to an embodiment.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. In the embodiment, a dump truck, which is a transport vehicle that travels to a work site such as a mine and transports cargo, is used as a work vehicle that configures a fuel cell system.

[0011] <Dump Truck> Fig. 1 is a side view of a dump truck 2 according to an embodiment. Fig. 2 is a block diagram of the circuit configuration of a fuel cell system 1 according to an embodiment. Referring to Figs. 1 and 2 together, the dump truck 2 is equipped with a drive source 30 (corresponding to an FC stack) that uses hydrogen as fuel. The dump truck 2 is equipped with an electrolysis device 40 that uses electric power to electrolyze water generated from the drive source 30 or water stored in a water tank 41.

[0012] The dump truck 2 includes a body frame 10 on which a drive source 30 using hydrogen as fuel is mounted, a dump body 12 (corresponding to a vessel) that is rotatably connected to the body frame 10 via a rotating section 11 and that carries a load, and a traveling device 13 that supports the body frame 10. For example, the dump truck 2 may be an unmanned dump truck that is driven without being operated by a driver, or may be a manned dump truck that is driven based on operation by a driver.

[0013] Hereinafter, the forward direction (front of the vehicle body), backward direction (rear of the vehicle body), and vehicle width direction (left and right direction of the vehicle body) of the dump truck 2 will be referred to as "front of the vehicle (one side in the front-to-rear direction of the vehicle)," "rear of the vehicle (the other side in the front-to-rear direction of the vehicle)," and "vehicle width direction." The vehicle width direction may also be referred to as "left side (one side in the vehicle width direction)" or "right side (the other side in the vehicle width direction)." The right side of the forward direction of the dump truck 2 will be referred to as the right side, and the left side of the forward direction of the dump truck 2 will be referred to as the left side. The vehicle up-down direction (up-down direction of the vehicle body), above the vehicle (above the vehicle body), and below the vehicle (below the vehicle body) of the dump truck 2 will be simply referred to as the "up-down direction," "upper," and "lower." In the example shown in the figure, the dump truck 2 is placed on a horizontal plane (level ground). The vehicle up-down direction (vehicle body up-down direction), vehicle upper side (vehicle body up) and vehicle lower side (vehicle body down) of the dump truck 2 correspond to the up-down direction (vertical direction), vertical upper side and vertical lower side when the dump truck 2 is placed on a horizontal plane.

[0014] The body frame 10 extends in the longitudinal direction of the vehicle. The body frame 10 rotatably supports a dump truck body 12 via a rotating portion 11. The rotating portion 11 is a portion including an axis portion (corresponding to the central axis of rotation of the dump truck body 12) extending in the width direction of the vehicle on the body frame 10. The body frame 10 is supported by a traveling device 13.

[0015] The dump body 12 is rotatably connected to the vehicle body frame 10 by a rotating portion 11. The dump body 12 is a member (corresponding to a loading platform) on which a load is carried. At least a portion of the dump body 12 is disposed above the vehicle body frame 10. The dump body 12 is capable of performing a dumping operation and a lowering operation.

[0016] The dumping operation refers to an operation of moving the dump body 12 away from the vehicle body frame 10 and tilting it in a dumping direction. The dumping direction is toward the rear of the vehicle body frame 10. In the embodiment, the dumping operation includes lifting the front end of the dump body 12 and tilting the dump body 12 rearward. Due to the dumping operation, the loading surface of the dump body 12 tilts downward toward the rear.

[0017] The lowering operation refers to an operation of bringing the dump body 12 closer to the vehicle body frame 10. The lowering operation is an operation in the opposite direction to the dumping operation. In the embodiment, the lowering operation includes lowering the front end of the dump body 12.

[0018] The dump body 12 is adjusted to a dump position and a loaded position by the dumping operation and the lowering operation. The dump position means a position in which the dump body 12 is raised. The loaded position means a position in which the dump body 12 is lowered. In the example of Figure 1, the dump body 12 in the loaded position is shown by a solid line, and the dump body 12 in the dump position is shown by a two-dot chain line.

[0019] For example, when performing an earth removal operation, the dump body 12 performs a dumping operation to change from a loaded position to a dumping position. When a load is loaded on the dump body 12, the load is discharged rearward from the rear end of the dump body 12 by the dumping operation. On the other hand, when a loading operation is performed, the dump body 12 is adjusted to the loaded position.

[0020] The dump body 12 is provided with a protector 16 that protects the cab 15 from above. The protector 16 is arranged to cover the cab 15 from above when the dump body 12 is in the loaded position. The protector 16 is provided on the front end side of the dump body 12. The protector 16 is arranged above the cab 15. The protector 16 extends in the vehicle width direction. For example, the cab 15 is arranged to the left of the center of the vehicle width direction.

[0021] The cab 15 is supported by a platform 17. The platform 17 is provided above the front of the body frame 10. The platform 17 is provided to ensure a foothold when the operator gets in and out of the cab 15. The platform 17 is provided to ensure a foothold when maintenance is performed on equipment mounted on the dump truck 2. The platform 17 is located below the protector 16. The platform 17 is located above the wheels 21, 22. The platform 17 extends in the vehicle width direction. The platform 17 is formed in a plate shape that is parallel to the vehicle front-rear direction and the vehicle width direction.

[0022] The traveling device 13 supports the body frame 10. The traveling device 13 causes the dump truck 2 to travel. The traveling device 13 causes the dump truck 2 to move forward or backward. At least a portion of the traveling device 13 is disposed below the body frame 10. The traveling device 13 includes a plurality of wheels 21, 22. The plurality of wheels 21, 22 includes front wheels 21 and rear wheels 22 disposed rearward of the front wheels 21.

[0023] The front wheels 21 are steered wheels that are steered to change the traveling direction of the dump truck 2. A pair of left and right front wheels 21 are arranged. The pair of left and right front wheels 21 are arranged with a gap in the vehicle width direction via the front part of the body frame 10. One front wheel 21 is provided on each side (two in total).

[0024] The rear wheels 22 are drive wheels driven by the drive source 30. A pair of left and right rear wheels 22 are arranged at a distance in the vehicle width direction via the rear part of the body frame 10. Two rear wheels 22 are provided on each side (four in total).

[0025] <Fuel Cell System> Figure 2 is a block diagram of the circuit configuration of a fuel cell system 1 according to an embodiment. Figure 3 is an explanatory diagram of the flow of electricity and the like during running in the fuel cell system 1 according to an embodiment. Figure 4 is an explanatory diagram of the flow of electricity and the like during regeneration in the fuel cell system 1 according to an embodiment. In the diagram, the flow of electricity is indicated by dotted arrows, the flow of oxygen by dashed arrows, the flow of hydrogen by solid arrows, and the flow of produced water (water) by dashed arrows.

[0026] 2 to 4 , the fuel cell system 1 (an example of a system) includes a drive source 30 (corresponding to an FC stack), a hydrogen tank 31, a traction motor 35, a battery 36, an electrolyzer 40, a water tank 41, a gas-liquid separator 45, a water purifier 46, and a pump 51 (corresponding to a recirculation pump). For example, the components of the fuel cell system 1 are mounted on a vehicle body frame 10.

[0027] The driving source 30 is a fuel cell (FC) that generates electricity by chemically reacting hydrogen, which is a fuel gas, with oxygen, which is an oxidizing gas. For example, the fuel cell has a stack structure in which multiple unit cells are stacked. For example, the fuel cell generates electricity by using oxygen contained in the outside air. Note that the fuel cell may be supplied with air containing oxygen by an oxidizing gas supply device (not shown).

[0028] The hydrogen tank 31 is a tank that stores hydrogen. For example, the hydrogen tank 31 preferably has a cylindrical shape. In the example of FIG. 2, one hydrogen tank 31 is shown. Note that the shape and number of the hydrogen tanks 31 are not limited to those described above. For example, the hydrogen tank 31 may have a flat shape. For example, the number of hydrogen tanks 31 may be two or more. For example, the shape and number of the hydrogen tanks 31 can be changed according to design specifications.

[0029] The travel motor 35 is a motor for traveling the dump truck 2. The travel motor 35 is electrically connected to the drive source 30. The travel motor 35 is connected to the rear wheels 22 of the travel device 13. The rotational force generated by the travel motor 35 is transmitted to the rear wheels 22 of the travel device 13.

[0030] For example, the battery 36 is a secondary battery such as a lithium-ion battery. The battery 36 is electrically connected to the traveling motor 35. For example, the electric power charged in the battery 36 is used as driving energy when the dump truck 2 is powered. The battery 36 stores regenerative electric power of the traveling motor 35 that is generated when the dump truck 2 goes downhill or decelerates. Note that the battery 36 may also store electric power generated by the driving source 30.

[0031] The electrolyzer 40 uses electric power to electrolyze water generated by the driving source 30 or water stored in the water tank 41. Electrolysis of water by the electrolyzer 40 generates hydrogen and oxygen. In this embodiment, the hydrogen generated by the electrolyzer 40 is used as fuel for the driving source 30. Meanwhile, the generated oxygen is exhausted to the outside.

[0032] The electrolyzer 40 is electrically connected to the travel motor 35. The electrolyzer 40 uses, as its power, regenerative power of the travel motor 35 generated when the dump truck 2 goes downhill or decelerates. The electrolyzer 40 uses, as its power, surplus power that is not charged into the battery 36 out of the regenerative power generated by the travel motor 35.

[0033] For example, information regarding the power that can be charged to the battery 36 (hereinafter also referred to as "battery capacity") and the regenerative power generated by the traction motor 35 (hereinafter also referred to as "motor power generation amount") may be input to a controller (not shown). For example, when the motor power generation amount exceeds the battery capacity, the controller may determine that the regenerative power generated by the traction motor 35 will not be charged to the battery 36. For example, the controller may calculate the surplus power by subtracting the battery capacity (specifically, the remaining capacity of the battery 36) from the motor power generation amount.

[0034] The water tank 41 is a tank for storing water. For example, the water tank 41 may be mounted on the electrolyzer 40. Alternatively, the water tank 41 may be provided outside the electrolyzer 40. For example, the installation mode of the water tank 41 can be changed according to design specifications.

[0035] The gas-liquid separator 45 separates surplus hydrogen that is not used by the driving source 30 from the hydrogen supplied to the driving source 30, and the water generated by the driving source 30. The water separated by the gas-liquid separator 45 is supplied to the water tank 41.

[0036] For example, water purifier 46 is a filter for purifying the water decomposed in electrolyzer 40. For example, water purifier 46 may be configured with a dust filter, a chemical filter, a catalyst, or the like. For example, the configuration of water purifier 46 can be changed according to design specifications.

[0037] The water purifier 46 purifies the produced water or the stored water. In this embodiment, the water purifier 46 purifies the produced water separated by the gas-liquid separator 45. The electrolyzer 40 electrolyzes the purified water purified by the water purifier 46.

[0038] In the illustrated example, water purifier 46 is provided upstream of electrolyzer 40. Specifically, water purifier 46 is provided midway through the pipe connecting gas-liquid separator 45 and water tank 41. Water purifier 46 may also be provided inside electrolyzer 40. For example, water purifier 46 may be provided downstream of water tank 41. For example, the installation mode of water purifier 46 can be changed depending on the design specifications.

[0039] The fuel cell system 1 further includes a hydrogen supply pipe 32 for supplying hydrogen stored in the hydrogen tank 31 to the driving source 30, and a hydrogen circulation mechanism 50 for circulating surplus hydrogen that is not used by the driving source 30 among the hydrogen supplied to the driving source 30 between the hydrogen supply pipe 32 and the driving source 30.

[0040] The portion of the hydrogen supply pipe 32 opposite to the portion connected to the hydrogen tank 31 is connected to the driving source 30. For example, the hydrogen supply pipe 32 is preferably made of a high-pressure metal pipe that can withstand high-pressure hydrogen (for example, approximately 70 MPa). A pressure reducing valve for reducing the pressure of the high-pressure hydrogen may be provided midway along the hydrogen supply pipe 32.

[0041] The pump 51 is a component of the hydrogen circulation mechanism 50. The hydrogen circulation mechanism 50 includes the pump 51 that sends pressurized hydrogen obtained by pressurizing surplus hydrogen to the hydrogen supply pipe 32, an upstream pipe 52 and a downstream pipe 53 through which surplus hydrogen from the driving source 30 flows, and a junction pipe 56 through which hydrogen generated from the electrolyzer 40 flows.

[0042] The upstream pipe 52 connects the driving source 30 and the pump 51. The upstream pipe 52 is provided upstream of the pump 51. The junction pipe 56 connects the electrolyzer 40 and the upstream pipe 52. The junction pipe 56 supplies the water generated by the electrolyzer 40 to the upstream pipe 52. The hydrogen generated by the electrolyzer 40 (e.g., hydrogen at room temperature and normal pressure) is supplied to the upstream pipe 52 through the junction pipe 56. Excess hydrogen from the driving source 30 and hydrogen generated by the electrolyzer 40 (both of which are low-pressure hydrogen before being pressurized by the pump 51) flow through the upstream pipe 52. For example, a gas-liquid separator 45 may be provided midway along the upstream pipe 52.

[0043] The downstream pipe 53 connects the hydrogen supply pipe 32 and the pump 51. The downstream pipe 53 is provided downstream of the pump 51. Pressurized hydrogen, which is part of the surplus hydrogen from the driving source 30 and has been pressurized by the pump 51, flows through the downstream pipe 53. Therefore, the pressure of the pressurized hydrogen flowing through the downstream pipe 53 is higher than the pressure of hydrogen flowing through the upstream pipe 52.

[0044] The fuel cell system 1 further includes a hydrogen reflux mechanism 55 that returns excess hydrogen that is not used by the driving source 30, out of the hydrogen supplied to the driving source 30, to the hydrogen supply pipe 32. The upstream pipe 52 and the downstream pipe 53 are components of the hydrogen reflux mechanism 55. For example, the hydrogen reflux mechanism 55 may be formed by at least a part of the hydrogen circulation mechanism 50.

[0045] Switching valves for switching the flow of the various fluids may be provided midway through the various pipes. For example, the switching valves may be provided at branching portions of the pipes. For example, the controller may control the switching valves so that the flow of the various fluids is switched depending on the driving state of the dump truck 2 (for example, during travel, during regeneration, etc.).

[0046] <Flow of electricity, etc. while traveling> Next, an example of the flow of electricity, etc. while the dump truck 2 is traveling will be described with reference to Fig. 3 etc. Hydrogen is supplied to the driving source 30 from a hydrogen tank 31. The driving source 30 generates electricity by causing a chemical reaction between hydrogen, which is a fuel gas, and oxygen, which is an oxidizing gas. The driving source 30 generates electricity by utilizing oxygen contained in the outside air.

[0047] The gas-liquid separator 45 separates the water produced by the driving source 30 from the excess hydrogen supplied to the driving source 30 that is not used by the driving source 30. The water separated by the gas-liquid separator 45 is supplied (stored) in the water tank 41. The excess hydrogen separated by the gas-liquid separator 45 is supplied again to the driving source 30 as fuel for the driving source 30 by a hydrogen circulation mechanism 50 including a pump 51 and the like.

[0048] The electric power generated by the drive source 30 (hereinafter also referred to as "FC output") is used as drive energy for the travel motor 35. The driving of the travel motor 35 causes the rear wheels 22 (tires), which are drive wheels, to rotate. This causes the dump truck 2 to travel. The electric power charged in the battery 36 is used as drive energy for the travel motor 35 when the dump truck 2 is powered (for example, when traveling loaded, climbing a slope, etc.). Any shortfall in the FC output is made up for by the battery 36 discharging.

[0049] <Flow of electricity, etc. during regeneration> Next, an example of the flow of electricity, etc. during regeneration (for example, during downhill or deceleration) of the dump truck 2 will be described with reference to Fig. 4 etc. The battery 36 is charged with regenerative power of the travel motor 35 generated when the dump truck 2 goes downhill or decelerates. Of the regenerative power generated by the travel motor 35, surplus power that is not charged into the battery 36 is used as power for the electrolyzer 40.

[0050] In the electrolyzer 40, surplus power is used to electrolyze the water stored in the water tank 41 (the product water separated by the gas-liquid separator 45). Hydrogen and oxygen are generated by the electrolysis of water. The hydrogen generated by the electrolyzer 40 is supplied to the driving source 30 via the junction pipe 56 or the like and is used as fuel for the driving source 30. Meanwhile, the generated oxygen is exhausted to the outside.

[0051] <Operation and Effect> As described above, the dump truck 2 of this embodiment is equipped with a drive source 30 that uses hydrogen as fuel. The dump truck 2 is equipped with an electrolyzer 40 that uses electric power to electrolyze produced water generated from the drive source 30 or stored water stored in the water tank 41. According to this configuration, hydrogen is generated by electrolyzing the produced water generated from the drive source 30 or stored water stored in the water tank 41 using the electric power used by the electrolyzer 40. The generated hydrogen can be used as drive energy for the dump truck 2. Therefore, energy loss can be suppressed.

[0052] In this embodiment, the hydrogen generated by the electrolyzer 40 is used as fuel for the driving source 30. With this configuration, the generated hydrogen can be used as fuel for the driving source 30. Therefore, fuel loss in the driving source 30 can be reduced. For example, the consumption of hydrogen in the hydrogen tank 31 can be reduced.

[0053] In the present embodiment, the dump truck 2 further includes a travel motor 35 that drives the dump truck 2. The electrolyzer 40 uses, as electric power, regenerative power of the travel motor 35 that is generated when the dump truck 2 travels downhill or decelerates. With this configuration, the regenerative power of the travel motor 35 can be effectively used as electric power for performing electrolysis.

[0054] In this embodiment, the dump truck 2 further includes a battery 36 that stores regenerated power generated by the traveling motor 35. The electrolyzer 40 uses, as its power, surplus power that is not charged into the battery 36 out of the regenerated power generated by the traveling motor 35. With this configuration, the surplus power that is not charged into the battery 36 can be effectively used as power for performing electrolysis. Therefore, loss of surplus power can be suppressed.

[0055] In the present embodiment, the dump truck 2 further includes a water purifying unit 46 that purifies the produced water or the stored water. The electrolyzing device 40 electrolyzes the purified water purified by the water purifying unit 46. With this configuration, electrolysis of the purified water generates hydrogen with higher purity. Therefore, the hydrogen with higher purity can be used as fuel for the drive source 30.

[0056] In this embodiment, the dump truck 2 further includes a hydrogen tank 31 that stores hydrogen, a hydrogen supply pipe 32 that supplies the hydrogen stored in the hydrogen tank 31 to the driving source 30, and a hydrogen circulation mechanism 50 that circulates surplus hydrogen that is supplied to the driving source 30 and is not used by the driving source 30 between the hydrogen supply pipe 32 and the driving source 30. With this configuration, the surplus hydrogen that is not used by the driving source 30 can be reused as fuel for the driving source 30. This makes it possible to more effectively suppress fuel loss in the driving source 30. This makes it possible to more effectively reduce hydrogen consumption in the hydrogen tank 31.

[0057] In this embodiment, the hydrogen circulation mechanism 50 includes a pump 51 that sends pressurized hydrogen to the hydrogen supply pipe 32, and an upstream pipe 52 that connects the drive source 30 and the pump 51 and through which surplus hydrogen from the drive source 30 flows. Hydrogen generated by the electrolyzer 40 is supplied to the upstream pipe 52. For example, if hydrogen generated by the electrolyzer 40 is directly supplied to the hydrogen supply pipe 32, the pressure of the hydrogen generated by the electrolyzer 40 needs to be increased. In contrast, with this configuration, the hydrogen generated by the electrolyzer 40 is supplied to the upstream pipe 52, so there is no need to increase the pressure of the hydrogen generated by the electrolyzer 40. In other words, no energy is required to increase the pressure of the hydrogen generated by the electrolyzer 40. Therefore, energy loss can be more effectively suppressed.

[0058] In the present embodiment, the dump truck 2 further includes a water tank 41 and a gas-liquid separator 45. The gas-liquid separator 45 separates surplus hydrogen that is not used by the drive source 30 from the hydrogen supplied to the drive source 30, and produced water that is produced by the drive source 30. The produced water separated by the gas-liquid separator 45 is supplied to the water tank 41. With this configuration, the produced water separated by the gas-liquid separator 45 can be stored in the water tank 41. Therefore, consumption of the water stored in the water tank 41 can be more effectively reduced. For example, by utilizing the produced water as water to be electrolyzed, it is possible to eliminate the need for an external water supply.

[0059] In this embodiment, the dump truck 2 further includes a hydrogen tank 31 that stores hydrogen, a hydrogen supply pipe 32 that supplies the hydrogen stored in the hydrogen tank 31 to the driving source 30, and a hydrogen return mechanism 55 that returns surplus hydrogen that is supplied to the driving source 30 and is not used by the driving source 30 to the hydrogen supply pipe 32. According to this configuration, by returning the surplus hydrogen that is not used by the driving source 30 to the hydrogen supply pipe 32, it can be used again as fuel for the driving source 30. Therefore, fuel loss in the driving source 30 can be more effectively suppressed. Therefore, consumption of hydrogen in the hydrogen tank 31 can be more effectively reduced.

[0060] <Modifications> In the above-described embodiment, the hydrogen generated by the electrolyzer is used as fuel for the driving source, but this is not limiting. For example, the hydrogen generated by the electrolyzer may be supplied to a hydrogen tank. For example, the manner in which the hydrogen generated by the electrolyzer is used can be modified depending on the design specifications.

[0061] In the above-described embodiment, an example has been described in which the work vehicle further includes a traction motor for propelling the work vehicle, but this is not limited to this. For example, the work vehicle does not need to include a traction motor. For example, if the drive source is a hydrogen engine, the work vehicle may be propelled by the hydrogen engine. For example, the installation mode of the traction motor can be changed depending on the design specifications.

[0062] In the above-described embodiment, an example has been described in which the electrolyzer uses regenerative power from the traction motor generated when the work vehicle goes downhill or decelerates, but this is not limiting. For example, the electrolyzer does not have to use regenerative power from the traction motor. For example, the electrolyzer may use power generated by a drive source. For example, the electrolyzer may use power charged in a battery. For example, the type of power used to perform electrolysis can be changed according to design specifications.

[0063] In the above-described embodiment, an example has been described in which the work vehicle further includes a battery that stores regenerated power generated by the traction motor, but this is not limited to this. For example, if the drive source is a hydrogen engine, the work vehicle does not need to include a battery. For example, the installation mode of the battery can be changed depending on the design specifications.

[0064] In the above-described embodiment, an example has been described in which the electrolyzer uses surplus power that is not charged to the battery out of the regenerated power generated by the traction motor as electric power, but this is not limited thereto. For example, the electrolyzer does not have to use the surplus power that is not charged to the battery. For example, the electrolyzer may use a portion of the regenerated power of the traction motor. For example, the regenerated power of the traction motor may be used simultaneously for both power used by the electrolyzer and for charging the battery. For example, the manner in which the regenerated power or surplus power of the traction motor is used can be changed according to design specifications.

[0065] In the above-described embodiment, the work vehicle is described as further including a water purifier that purifies produced water or stored water, but this is not limited thereto. For example, the work vehicle does not need to include a water purifier. For example, produced water generated from a drive source or stored water in a water tank may be directly electrolyzed. For example, the installation mode of the water purifier can be changed according to design specifications.

[0066] In the above-described embodiment, an example was described in which the work vehicle further includes a hydrogen tank for storing hydrogen, a hydrogen supply pipe for supplying hydrogen stored in the hydrogen tank to the power source, and a hydrogen circulation mechanism for circulating surplus hydrogen supplied to the power source that is not used by the power source between the hydrogen supply pipe and the power source, but this is not limited to this. For example, the work vehicle does not need to include at least one of the hydrogen tank, the hydrogen supply pipe, and the hydrogen circulation mechanism. For example, the installation manner of the hydrogen tank, the hydrogen supply pipe, and the hydrogen circulation mechanism can be changed depending on the design specifications.

[0067] In the above-described embodiment, the hydrogen circulation mechanism includes a pump that sends pressurized hydrogen to the hydrogen supply pipe and an upstream pipe that connects the drive source to the pump and through which excess hydrogen from the drive source flows, and hydrogen generated by the electrolyzer is supplied to the upstream pipe. However, this is not limiting. For example, hydrogen generated by the electrolyzer may be supplied to the hydrogen supply pipe. For example, the manner in which hydrogen generated by the electrolyzer is supplied can be changed depending on the design specifications.

[0068] In the above-described embodiment, an example has been described in which the work vehicle further includes a water tank and a gas-liquid separator that separates excess hydrogen supplied to the drive source that is not used by the drive source from water produced by the drive source, but this is not limited to this. For example, the work vehicle does not need to include at least one of the water tank and the gas-liquid separator. For example, the installation mode of the water tank and the gas-liquid separator can be changed depending on the design specifications.

[0069] In the above-described embodiment, an example has been described in which the produced water separated by the gas-liquid separator is supplied to a water tank, but this is not limiting. For example, the produced water separated by the gas-liquid separator does not have to be supplied to a water tank. For example, the produced water separated by the gas-liquid separator may be discharged to the outside. For example, the manner in which the produced water separated by the gas-liquid separator is used can be changed depending on the design specifications.

[0070] In the above-described embodiment, an example was described in which the work vehicle further includes a hydrogen tank for storing hydrogen, a hydrogen supply pipe for supplying hydrogen stored in the hydrogen tank to the power source, and a hydrogen reflux mechanism for returning excess hydrogen not used by the power source to the hydrogen supply pipe, but this is not limited to this. For example, the work vehicle does not need to include at least one of the hydrogen tank, the hydrogen supply pipe, and the hydrogen reflux mechanism. For example, the installation manner of the hydrogen tank, the hydrogen supply pipe, and the hydrogen reflux mechanism can be changed depending on the design specifications.

[0071] In the above-described embodiment, the driving source is described as a fuel cell (FC) that generates electricity by chemically reacting hydrogen, which is a fuel gas, with oxygen, which is an oxidizing gas. However, the driving source is not limited to this. For example, the driving source may be a hydrogen engine, which is an internal combustion engine that uses hydrogen as fuel. For example, the driving source may include a fuel cell and a hydrogen engine. For example, the configuration of the driving source may be changed depending on the design specifications.

[0072] In the above-described embodiment, the work vehicle is described as a dump truck by way of example, but is not limited to this. For example, the work vehicle may be another work vehicle such as a shovel, bulldozer, or wheel loader. For example, the configuration of the work vehicle can be changed according to design specifications.

[0073] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and additions, omissions, substitutions, and other modifications to the configuration are possible within the scope of the spirit of the present invention, and the above-described embodiments can also be combined as appropriate.

[0074] (Supplementary Note 1) A work vehicle equipped with a drive source that uses hydrogen as fuel, the work vehicle including an electrolysis device that uses electric power to electrolyze water generated from the drive source or water stored in a water tank.

[0075] (Supplementary Note 2) The work vehicle according to Supplementary Note 1, wherein hydrogen generated by the electrolysis device is used as fuel for the drive source.

[0076] (Supplementary Note 3) The work vehicle according to Supplementary Note 1 or 2, further comprising a traction motor for propelling the work vehicle, wherein the electrolyzer uses, as the electric power, regenerative power of the traction motor generated when the work vehicle goes downhill or decelerates.

[0077] (Supplementary Note 4) The work vehicle according to Supplementary Note 3, further comprising a battery that stores the regenerated power generated by the traction motor, wherein the electrolyzer uses, as the power, surplus power of the regenerated power generated by the traction motor that is not charged into the battery.

[0078] (Supplementary Note 5) The work vehicle according to any one of Supplementary Notes 1 to 4, further comprising a water purification unit that purifies the produced water or the stored water, wherein the electrolysis device electrolyzes purified water purified by the water purification unit.

[0079] (Supplementary Note 6) A work vehicle as described in any of Supplementary Notes 1 to 5, further comprising: a hydrogen tank for storing hydrogen; a hydrogen supply pipe for supplying the hydrogen stored in the hydrogen tank to the power source; and a hydrogen circulation mechanism for circulating surplus hydrogen that is not used by the power source among the hydrogen supplied to the power source between the hydrogen supply pipe and the power source.

[0080] (Supplementary Note 7) The work vehicle described in Supplementary Note 6, wherein the hydrogen circulation mechanism includes: a pump that sends pressurized hydrogen to the hydrogen supply pipe; and an upstream pipe that connects the drive source and the pump and through which the surplus hydrogen from the drive source flows; and the hydrogen generated by the electrolysis device is supplied to the upstream pipe.

[0081] (Supplementary Note 8) A work vehicle as described in any of Supplementary Note 1 to Supplementary Note 7, further comprising: the water tank; and a gas-liquid separator that separates surplus hydrogen that is not used by the drive source from the hydrogen supplied to the drive source, and the produced water produced from the drive source, and the produced water separated by the gas-liquid separator is supplied to the water tank.

[0082] (Supplementary Note 9) A work vehicle as described in any one of Supplementary Notes 1 to 8, further comprising: a hydrogen tank for storing hydrogen; a hydrogen supply pipe for supplying the hydrogen stored in the hydrogen tank to the power source; and a hydrogen return mechanism for returning surplus hydrogen that is not used by the power source out of the hydrogen supplied to the power source to the hydrogen supply pipe.

[0083] 2...Dump truck (work vehicle), 30...Drive source, 31...Hydrogen tank, 32...Hydrogen supply pipe, 35...Travel motor, 36...Battery, 40...Electrolyzer, 41...Water tank, 45...Gas-liquid separator, 46...Water purification unit, 50...Hydrogen circulation mechanism, 51...Pump, 52...Upstream piping, 55...Hydrogen reflux mechanism

Claims

1. An industrial vehicle equipped with a driving source using hydrogen as fuel, comprising an electrolysis device that electrolyzes generated water generated from the driving source using electricity or stored water stored in a water tank.

2. The industrial vehicle according to claim 1, wherein hydrogen generated by the electrolysis device is used as fuel for the driving source.

3. The industrial vehicle according to claim 1 or 2, further comprising a traveling motor for driving the industrial vehicle, wherein the electrolysis device uses, as the electricity, regenerative power of the traveling motor generated when the industrial vehicle descends a slope or decelerates.

4. The industrial vehicle according to claim 3, further comprising a battery for storing the regenerative power generated by the traveling motor, wherein the electrolysis device uses, as the electricity, surplus power of the regenerative power generated by the traveling motor that is not charged to the battery.

5. The industrial vehicle according to claim 1 or 2, further comprising a water purification unit for purifying the generated water or the stored water, wherein the electrolysis device electrolyzes the purified water purified by the water purification unit.

6. The industrial vehicle according to claim 1 or 2, further comprising a hydrogen tank for storing hydrogen, a hydrogen supply pipe for supplying hydrogen stored in the hydrogen tank to the driving source, and a hydrogen circulation mechanism for circulating surplus hydrogen that is not used by the driving source among the hydrogen supplied to the driving source between the hydrogen supply pipe and the driving source.

7. The hydrogen circulation mechanism according to claim 6 includes a pump for sending pressurized hydrogen to the hydrogen supply pipe and an upstream pipe connecting the driving source and the pump through which the surplus hydrogen from the driving source flows, and hydrogen generated by the electrolysis device is supplied to the upstream pipe.

8. The industrial vehicle according to claim 1 or 2, further comprising the water tank and a gas-liquid separation device for separating surplus hydrogen that is not used by the driving source among the hydrogen supplied to the driving source and the generated water generated from the driving source, and the generated water separated by the gas-liquid separation device is supplied to the water tank.

9. A hydrogen tank for storing hydrogen, a hydrogen supply pipe for supplying the hydrogen stored in the hydrogen tank to the drive source, and a hydrogen reflux mechanism for refluxing surplus hydrogen that is not utilized by the drive source among the hydrogen supplied to the drive source to the hydrogen supply pipe, the work vehicle according to claim 1 or 2, further comprising the same.

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