Work vehicle

Abstract

A work vehicle 1 according to the present disclosure comprises: a fuel cell (FC) module 24; a hydrogen tank 13 that stores hydrogen which is a fuel for the FC module 24; a motor 31 that is driven by power output from the FC module 24; and an FC system ECU 71 that can acquire a consumption command. When the FC system ECU 71 acquires the consumption command, the FC module 24 generates power until the hydrogen amount of the hydrogen tank 13 becomes a prescribed amount or less.

Description

Work vehicles

[0001] The present disclosure relates to work vehicles.

[0002] Patent Document 1 discloses a vehicle equipped with a motor, a fuel cell system that uses hydrogen as fuel, and a hydrogen tank. The fuel cell system generates electricity using hydrogen supplied from the hydrogen tank, and the generated electricity drives the motor to run the vehicle. This application claims priority to Japanese Patent Application Nos. 2023-219231 filed on December 26, 2023, and 2023-219043 filed on December 26, 2023, and incorporates all of the contents of those Japanese applications by reference.

[0003] Japanese Patent Application Laid-Open No. 2021-99945

[0004] The work vehicle disclosed herein includes a fuel cell, a hydrogen tank for storing hydrogen as fuel for the fuel cell, a motor driven by power output from the fuel cell, and a control device capable of receiving a consumption command. When the control device receives the consumption command, the fuel cell generates electricity until the amount of hydrogen in the hydrogen tank falls below a predetermined amount.

[0005] A work vehicle according to another aspect of the present disclosure includes a fuel cell, a fuel tank that stores fuel to be supplied to the fuel cell, a detection device that detects the state of fuel released from the fuel tank, and a control device that calculates the amount of fuel released and the amount of fuel consumed by the fuel cell based on the state of the fuel detected by the detection device.

[0006] FIG. 1 is a perspective view showing an example of the overall structure of a work vehicle. FIG. 2 is a right side view of the work vehicle with some exterior parts removed. FIG. 3 is a perspective view showing an example of the internal structure of the work vehicle. FIG. 4 is a block diagram showing an example of an FC power generation system for a work vehicle. FIG. 5 is a block diagram showing an example of the configuration of a control unit according to the first embodiment. FIG. 6 is a flowchart showing an example of consumption processing. FIG. 7 is a block diagram showing an example of the configuration of a control unit according to the second embodiment. FIG. 8 is a flowchart showing an example of consumption processing during autonomous driving. FIG. 9 is a part of a flowchart showing an example of consumption processing according to a modified example of the first embodiment. FIG. 10 is a perspective view of a work vehicle. FIG. 11 is a right side view of a work vehicle with some exterior parts removed. FIG. 12 is a perspective view showing an example of the internal structure of a work vehicle. FIG. 13 is a block diagram showing an example of the functional configuration of a work vehicle. FIG. 14 is a graph explaining an abnormality determination method used in hydrogen supply monitoring control. FIG. 15 is a flowchart showing an example of an abnormality determination procedure by a control device.

[0007] Chapter 1 Next, preferred embodiments of the present disclosure in Chapter 1 will be described with reference to the accompanying drawings. Problems to be Solved by the Present Disclosure The fuel cell system described above may be applied to a work vehicle used in agricultural work. Work vehicles are used frequently during work seasons, but are rarely used outside of work seasons and may remain stopped for long periods of time. When the work season ends and the work vehicle is stopped for an extended period of time, hydrogen may remain in the hydrogen tank installed in the work vehicle. When hydrogen remains in the hydrogen tank of a work vehicle that is stopped for an extended period of time, handling of the remaining hydrogen may become an issue. For this reason, a technology that can appropriately process the hydrogen remaining in the hydrogen tank is desired.

[0008] [Effects of the Present Disclosure] According to the present disclosure, hydrogen remaining in a hydrogen tank can be appropriately disposed of.

[0009] The contents of the embodiment will be listed and explained below. [Outline of the embodiment]

[0010] (1) A work vehicle disclosed herein includes a fuel cell, a hydrogen tank for storing hydrogen as fuel for the fuel cell, a motor driven by power output from the fuel cell, and a control device capable of receiving a consumption command. When the control device receives the consumption command, the fuel cell generates electricity until the amount of hydrogen in the hydrogen tank falls below a predetermined amount.

[0011] According to the above configuration, when the control device receives a consumption command, the fuel cell starts generating electricity, and stops generating electricity when the amount of hydrogen in the hydrogen tank falls below a predetermined level. Therefore, for example, if the control device receives a consumption command when a work vehicle is parked for an extended period of time, the hydrogen remaining in the hydrogen tank can be consumed until the amount falls below a predetermined level, thereby reducing the amount of hydrogen in the hydrogen tank of a work vehicle parked for an extended period of time. In this way, the hydrogen remaining in the hydrogen tank can be properly disposed of.

[0012] (2) The work vehicle of (1) above may further include an operating unit that outputs the consumption command to the control device when an operation input is received via an operating member. In this case, the fuel cell can be caused to consume hydrogen remaining in the hydrogen tank until the amount falls below a predetermined amount in response to an external operation input.

[0013] (3) The work vehicle of (2) above may further include a position detection unit that detects the position of the vehicle itself, and an output device that, if the position detected by the position detection unit is determined to be the location of the storage location of the vehicle itself, outputs to the outside a message that an operation input should be made to the operating member. In this case, if there is a possibility that the work vehicle will be parked at the storage location for an extended period of time, the occupant can be prompted to dispose of any hydrogen remaining in the hydrogen tank.

[0014] (4) In the work vehicle of (2) or (3) above, the process of outputting the consumption command to the control device performed by the operation unit may be executed when the amount of hydrogen in the hydrogen tank is equal to or less than a threshold value, in addition to receiving the operation input. In this case, by appropriately setting the threshold value, it is possible to prevent the consumption command from being output when a large amount of hydrogen remains in the hydrogen tank, thereby preventing unnecessary consumption of hydrogen from the hydrogen tank.

[0015] (5) In the work vehicle of (4) above, the predetermined amount may be a value in which the amount of hydrogen is smaller than the threshold value. In this case, hydrogen is consumed by the difference between the threshold value and the predetermined amount.

[0016] (6) The work vehicle of any one of (1) to (5) above may further include a plan processing unit that executes processing to output the consumption command to the control device when the contents of the work plan for the vehicle indicate that the vehicle will be stopped for a certain period of time from the present time. In this case, if it is clear that the work vehicle will be stopped for a certain period of time, the hydrogen remaining in the hydrogen tank is disposed of. Thus, the hydrogen remaining in the hydrogen tank can be appropriately disposed of without any operation by the occupants of the work vehicle.

[0017] (7) In the work vehicle according to any one of (1) to (6) above, if the work vehicle further includes a power storage device that stores the electric power generated by the fuel cell, the electric power generated by the fuel cell when the consumption command is received may be stored in the power storage device. In this case, the electric power obtained from the hydrogen remaining in the hydrogen tank can be stored in the power storage device.

[0018] (8) In the work vehicle described in (7) above, if an auxiliary power storage device is further provided, the power generated by the fuel cell may be stored in the auxiliary power storage device when the power storage device is fully charged. In this case, even when the power storage device is fully charged, the power obtained from the hydrogen remaining in the hydrogen tank can be stored in the auxiliary power storage device.

[0019] (9) Furthermore, in the work vehicle of (7) above, if an external output unit is further provided that outputs the electric power generated by the fuel cell to an external device, when the power storage device is fully charged, the electric power generated by the fuel cell may be output to an external device connected to the external output unit. In this case, even when the power storage device is fully charged, the electric power obtained from the hydrogen remaining in the hydrogen tank can be consumed by the external device.

[0020] Another aspect of the present disclosure is a control device for use in a work vehicle equipped with a fuel cell, a hydrogen tank for storing hydrogen as fuel for the fuel cell, and a motor driven by electric power output from the fuel cell. The control device includes a processing unit that, upon receiving a consumption command, causes the fuel cell to generate electric power until the amount of hydrogen in the hydrogen tank falls below a predetermined amount.

[0021] [Details of the embodiment] Preferred embodiments will now be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any desired manner.

[0022] [Overall Structure of Work Vehicle] Fig. 1 is a perspective view showing an example of the overall structure of a work vehicle 1. Fig. 2 is a right side view of the work vehicle 1 with some exterior parts (such as the hood 34 and cover 111) removed. As shown in Figs. 1 and 2, the work vehicle 1 is a vehicle used for agricultural work, specifically a tractor. However, the work vehicle 1 is not limited to a tractor, and may be a mobile body such as agricultural machinery, construction machinery, or a utility vehicle.

[0023] The work vehicle 1 includes a vehicle body 11, a running device 12 that supports the vehicle body 11, a driver's seat 15, and a cabin 16. The vehicle body 11 includes a chassis 41, a hood 34, a cover 111, the cabin 16, and fenders for the rear wheels 12B. More specifically, the hood 34, the cover 111, and the cabin 16 are arranged on the chassis 41 of the vehicle body 11 in this order from the front to the rear.

[0024] The work vehicle 1 further has a tank unit 21 and a drive device 14. The tank unit 21 has multiple hydrogen tanks 13 (see FIG. 2) therein for storing fuel. The drive device 14 outputs drive force using the fuel stored in the tank unit 21. The fuel is liquid or gas, such as hydrogen, methane, or carbon monoxide (CO). The fuel in this embodiment is hydrogen. Each of the multiple tanks 13 stores hydrogen gas. The work vehicle 1 is a fuel cell vehicle (FCV). The work vehicle 1 has a fuel cell power generation system (FC power generation system). The work vehicle 1 travels using power generated by the FC power generation system as an energy source. Note that the FC power generation system in this embodiment generates power using hydrogen. The FC power generation system may also generate power using methane or carbon monoxide (CO).

[0025] The drive device 14 includes a fuel cell module (FC module) 24, a battery unit 30, and an electric motor 31 (see FIG. 3; hereinafter also referred to as "motor 31"). The battery unit 30 has a built-in battery pack 30A (see FIG. 4). The battery unit 30 stores the power output by the FC module 24. The work vehicle 1 has hydrogen gas piping 22. Hydrogen gas is filled into each hydrogen tank 13 through a fill port 52 (see FIG. 4) provided at the end of the piping 22. Hydrogen in the hydrogen tank 13 is supplied to the FC module 24 through the piping 22.

[0026] The cabin 16 is a partitioned driver's compartment. The cabin 16 has front pillars, rear pillars, and a roof. The front pillars are located on the left and right sides in front of the driver's seat 15, and the rear pillars are located on the left and right sides behind the driver's seat 15. The work vehicle 1 may have a canopy or roofing instead of the cabin 16. If the work vehicle 1 does not have a cabin 16, the tank unit 21 is placed above the driver's seat 15 by a mounting frame 17, which will be described later.

[0027] The traveling device 12 is composed of front wheels 12A and rear wheels 12B, both of which are arranged symmetrically on the left and right sides of the vehicle body 11. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of a motor 31. One or both of the wheels 12A, 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers).

[0028] 2, a first radiator 48, an FC module 24, and a second radiator 49 are mounted in this order from front to rear on a portion of the chassis 41 corresponding to the front wheels 12A. The first radiator 48 and the FC module 24 are covered by the hood 34. The second radiator 49 is covered by a cover 111.

[0029] 1, the top surface of the cover 111 is higher than the top edge of the hood 34 but lower than the top edge of the steering wheel of the driver's seat 15. The rear end of the hood 34 is located lower than the cover 111, and the top surface of the hood 34 is tapered, gradually lowering from the rear end toward the front end. This structure makes it difficult for the forward visibility of the operator sitting in the driver's seat 15 to be obstructed.

[0030] [Internal Structure of Work Vehicle] Figure 3 is a perspective view showing an example of the internal structure of the work vehicle 1. As shown in Figure 3, a chassis 41 that constitutes the vehicle body 11 has a front frame 32 and a transmission case 33. The front frame 32 is made of a steel frame that is long in the front-to-rear direction. The transmission case 33 is connected to the rear of the front frame 32. The framework of the vehicle body 11 is formed by the transmission case 33 and the front frame 32.

[0031] A mounting frame 17 is connected to the chassis 41. The mounting frame 17 is a frame for disposing the tank unit 21 above the cabin 16. The mounting frame 17 includes a ceiling frame 17A, multiple pillars 17B, and a pair of left and right reinforcing frames 17C. The ceiling frame 17A has a substantially rectangular shape that is longer in the front-to-rear direction than in the left-to-right direction. The multiple pillars 17B support the ceiling frame 17A from below. The pair of reinforcing frames 17C are provided on the left and right sides of the front end of the ceiling frame 17A.

[0032] The tank unit 21 is connected to the ceiling frame 17A in a horizontally placed state. As shown in Figure 2, the ceiling frame 17A is located higher than the roof of the cabin 16. Therefore, the tank unit 21 is disposed above the roof of the cabin 16. The reinforcing frame 17C is a reinforcing diagonal member that slopes downward from the front end of the ceiling frame 17A to the front frame 32. Therefore, the rigidity of the mounting frame 17 in the fore-and-aft direction is strengthened compared to when the ceiling frame 17A and the tank unit 21 are supported only by the pillars 17B.

[0033] A support frame 37 for supporting the battery unit 30 on the vehicle body 11 is connected to the chassis 41 of the work vehicle 1. Specifically, the motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to a portion of the front frame 32 corresponding to the motor 31. The support frame 37 is made of, for example, a metal frame member, and is attached in a cantilevered state so as to protrude to the right from the front frame 32.

[0034] The transmission case 33, located rearward of the motor 31, houses a power transmission mechanism therein. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and transmits the rotation of the output shaft of the motor 31 to the traveling device 12 while slowing or accelerating the rotation. The power transmission mechanism also includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIG. 4). The PTO shaft 334 is an output shaft that protrudes rearward from the transmission case 33.

[0035] A coupling device 44 (see FIG. 2), which is configured, for example, as a three-point linkage, is attached to the transmission case 33 for coupling a work implement 335 (see FIG. 4) for performing a desired agricultural task to the rear of the vehicle body 11. The three-point linkage may be configured, for example, with an upper arm 44A protruding rearward from the transmission case 33 and a pair of left and right lower arms 44B. The work implement 335 may be, for example, a cultivator or a baler.

[0036] For example, while the traveling device 12 is being driven, the rotational motion of the PTO shaft 334 is transmitted to the input shaft of the working device 335 connected to the coupling device 44. Therefore, the work vehicle 1 can drive the working device 335 with the power of the motor 31 while traveling in a field or the like.

[0037] [Regarding the power generation system of the work vehicle] Figure 4 is a block diagram showing an example of an FC power generation system of a work vehicle 1. In addition to the FC power generation system, Figure 4 also shows a motor 31 driven by power generated by the FC power generation system, the traveling device 12, and the work device 335. The FC power generation system includes the FC module 24 and battery unit 30 included in the drive device 14, as well as a tank unit 21, a first DC / DC converter 64, a second DC / DC converter 65, etc.

[0038] As shown in FIG. 4 , the FC module 24 includes a fuel cell stack 24a, a boost circuit 24b, and an ECU 24c. The fuel cell stack (FC stack) 24a has a stacked structure in which a plurality of fuel cell units (single cells) are stacked. The multiple single cells are connected in series to obtain a desired voltage. The FC stack 24a is supplied with hydrogen as fuel and air (oxygen). The FC module 24 includes a compressor and a pump (not shown) for supplying the hydrogen and air to the FC stack 24a. The FC stack 24a outputs (generates) electricity through an electrochemical reaction between the hydrogen and air.

[0039] Hydrogen supplied to the FC stack 24a is provided through the piping 22 as described above. As shown in FIG. 4 , the piping 22 connects the FC stack 24a and the tank unit 21. The piping 22 has a pipe section 22A and a pipe section 22B. The pipe section 22A is a gas pipe connecting the filling port 52 and the tank unit 21. The pipe section 22A guides hydrogen introduced into the filling port 52 to the tank unit 21. The pipe section 22B is a gas pipe connecting the FC stack 24a and the tank unit 21. The pipe section 22B guides hydrogen stored in the tank unit 21 to the FC stack 24a. The pipe section 22B is provided with a pressure sensor 53 for determining the amount of hydrogen in the tank unit 21. The pipe section 22B is also provided with an on-off valve 50. The on-off valve 50 is provided between the pressure sensor 53 and the FC stack 24a. When the on-off valve 50 is opened, hydrogen is supplied to the FC module 24. When the on-off valve 50 is closed, the supply of hydrogen to the FC module 24 is stopped.

[0040] The tank unit 21 has a valve unit 51 in addition to a plurality of hydrogen tanks 13. The valve unit 51 is connected to the plurality of hydrogen tanks 13. The valve unit 51 has the function of distributing hydrogen introduced from a filling port 52 to the plurality of hydrogen tanks 13, and of collecting hydrogen from the plurality of hydrogen tanks 13, adjusting the flow rate to a predetermined value, and supplying the collected hydrogen to the FC stack 24a. The tank unit 21 has a temperature sensor 54. The temperature sensor 54 measures the temperature inside the tank unit 21 as the temperature of the hydrogen.

[0041] The power generated by the FC stack 24a is supplied to the boost circuit 24b. The boost circuit 24b boosts the supplied power to a predetermined voltage. The FC module 24 outputs the power boosted by the boost circuit 24b to a subsequent stage. The ECU 24c has the function of controlling each part of the FC module 24.

[0042] An output terminal of the boost circuit 24b is connected to an electric circuit 25. The battery unit 30, the first DC / DC converter 64, and the second DC / DC converter 65 are connected to the boost circuit 24b via the electric circuit 25. The power output from the boost circuit 24b is supplied to each component via the electric circuit 25.

[0043] As described above, the battery unit 30 includes the battery pack 30A. The battery pack 30A is a power storage device that stores the power generated by the FC module 24. The battery pack 30A discharges the stored power. The power discharged from the battery pack 30A is provided to the inverter 62, the first DC / DC converter 64, and the second DC / DC converter 65 via the electrical path 25.

[0044] The battery pack 30A includes a battery management unit (BMU) 30A1 in addition to a battery main body including multiple secondary battery cells. The battery main body included in the battery pack 30A is, for example, a lithium-ion battery. The rated voltage of the battery main body (battery pack 30A) is several hundred volts. The BMU 30A1 has a function of monitoring and protecting the battery main body. The BMU 30A1 also has a function of controlling the charge and discharge of the battery main body and measuring the charge amount (for example, SOC).

[0045] An inverter 62 is also connected to the electric circuit 25. The inverter 62 has the function of providing power from the FC power generation system to the motor 31 and controlling the rotational output of the motor 31. The inverter 62 has the function of converting DC power provided from the FC module 24 or the battery unit 30 into three-phase AC power. The AC power output by the inverter 62 is provided to the motor 31. The inverter 62 controls the rotational output of the motor in accordance with control commands and the like provided from a control unit 70, which will be described later. The inverter 62 has an ECU 62a. The ECU 62a has the function of controlling the circuits of the inverter 62 based on the control commands and the like.

[0046] The motor 31 outputs rotational force using AC power supplied from the inverter 62. The rotational force output by the motor 31 is provided to a power transmission mechanism 33a in the transmission case 33. The power transmission mechanism 33a outputs all or part of the rotational force of the motor 31 to the traveling device 12. When the working device 335 is operated, the power transmission mechanism 33a outputs part of the rotational force of the motor 31 to the working device 335.

[0047] The first DC / DC converter 64 steps down the voltage of the DC power output from the FC module 24 or the battery unit 30 to a first voltage (e.g., 12 volts). The output terminal of the first DC / DC converter 64 is connected to the lead-acid battery 63, the auxiliary storage battery 67, the external output unit 66, and electrical equipment and auxiliary machinery such as lamps of the work vehicle 1. The power output by the first DC / DC converter 64 is provided to these devices. The first DC / DC converter 64 has an ECU 64a. The ECU 64a has a function of controlling the circuits of the first DC / DC converter 64 based on commands from the control unit, etc.

[0048] The lead-acid battery 63 stores the power output by the first DC / DC converter 64. The power stored in the lead-acid battery 63 is provided to electrical components and auxiliary machinery. A switch 63a is provided between the lead-acid battery 63 and the first DC / DC converter 64. The switch 63a has a function of opening and closing the connection between the lead-acid battery 63 and the first DC / DC converter 64. The external output unit 66 is an interface for outputting power from the first DC / DC converter 64 to equipment external to the work vehicle 1. When an external device is connected to the external output unit 66, power from the first DC / DC converter 64 is provided to the connected external device. The auxiliary storage battery 67 includes a secondary battery such as a lead-acid battery or a lithium-ion battery. Like the lead-acid battery 63, the auxiliary storage battery 67 stores the power output by the first DC / DC converter 64. The auxiliary storage battery 67 is an auxiliary power storage device that supplementarily stores the power generated by the FC module 24 .

[0049] The second DC / DC converter 65 steps down the voltage of the DC power output from the FC module 24 or the battery unit 30 to a second voltage (e.g., 24 volts). As with the first DC / DC converter 64, the output terminal of the second DC / DC converter 65 is connected to electrical components and auxiliary machinery of the work vehicle 1. The power output by the second DC / DC converter 65 is provided to these devices. The second DC / DC converter 65 has an ECU 65a. The ECU 65a has the function of controlling the circuits of the second DC / DC converter 65 based on commands from the control unit, etc.

[0050] 4, the work vehicle 1 further has a control unit 70. The control unit 70 has the function of controlling the FC power generation system including the FC module 24, receiving operation inputs from the occupant, and controlling the entire work vehicle 1 based on the received operation inputs.

[0051] 4, electronic control units such as ECU 24c, ECU 62a, ECU 64a, ECU 65a, and BMU 30A1 include, for example, a processor, a storage device, and an input / output interface. These electronic control units are connected to each other, for example, via a Controller Area Network (CAN) to enable mutual communication. Control unit 70 is also connected to the CAN.

[0052] Devices such as the on-off valve 50, the pressure sensor 53, the temperature sensor 54, and the switch 63a are also connected to the CAN, so that the control unit 70 can send control commands to these devices and receive outputs from these devices via the CAN.

[0053] The control unit 70 has a function of executing a consumption process that forcibly consumes the hydrogen remaining in the tank unit 21 .

[0054] [Regarding the Control Unit 70 According to the First Embodiment] Fig. 5 is a block diagram showing an example of the configuration of the control unit 70 according to the first embodiment. The control unit 70 includes an FC system ECU 71, an FC display panel 72, a main ECU 73, a main display panel 74, an operation device 75, a display switch 76, and a disposable switch 77. The FC system ECU 71 and the main ECU 73 are connected to a CAN. Therefore, the FC system ECU 71 and the main ECU 73 can communicate with the electronic control unit and various devices shown in Fig. 4.

[0055] The FC system ECU 71 and the main ECU 73 each include, for example, a processor (processing unit), a storage device, and an input / output interface. The processor includes a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), etc. The storage device includes, for example, a flash memory, a hard disk, a read-only memory (ROM), a random access memory (RAM), etc. The storage device stores computer programs to be executed by the processor and necessary information. The processor realizes its various processing functions by executing computer programs stored in a computer-readable, non-transitory recording medium such as a storage device.

[0056] The FC system ECU 71 has a function to control the FC power generation system including the FC module 24. Furthermore, when the FC system ECU 71 receives a consumption command, it functions as a control device that causes the FC module 24 to generate electricity until the amount of hydrogen in the tank unit 21 falls below a lower limit amount (predetermined amount) LA. The consumption command is a command to cause the FC module 24 to generate electricity until the amount of hydrogen in the tank unit 21 falls below the lower limit amount LA. Furthermore, the FC system ECU 71 also has a function to calculate the power that the FC module 24 can generate (generatable power) if hydrogen is used from the current amount of hydrogen in the tank unit 21 until it falls below the lower limit amount LA. The lower limit amount LA is the amount at which it can be determined that the hydrogen in the tank unit 21 is almost used up, and the amount at which it can be determined that the tank unit 21 is almost empty.

[0057] The FC system ECU 71 calculates the generateable power based on the output of the pressure sensor 53 and the output of the temperature sensor 54. The FC system ECU 71 stores a database that associates the output of the pressure sensor 53 (or the amount of hydrogen in the tank unit 21), the output of the temperature sensor 54 (or the temperature), and the generateable power. When the FC system ECU 71 acquires the outputs of the pressure sensor 53 and the temperature sensor 54, it refers to the database to calculate the generateable power. The FC system ECU 71 may calculate the generateable power using the output of the pressure sensor 53, or may calculate the generateable power using the amount of hydrogen in the tank unit 21 obtained from the output of the pressure sensor 53. The FC system ECU 71 may constantly calculate the generateable power, or may calculate the generateable power when output is needed.

[0058] The FC display panel 72 is connected to the FC system ECU 71. The FC display panel 72 displays and outputs various information indicating the operating status of the FC power generation system. The FC display panel 72 also functions as an output device that outputs the possible power to be generated. The FC display panel 72 can output the possible power to be generated by displaying a numerical value on the panel, or by an audio notification. The FC display panel 72 is provided in the driver's seat 15. Therefore, the FC display panel 72 outputs the possible power to the passenger.

[0059] The operation device 75 includes operation members such as an accelerator pedal and an accelerator lever for adjusting the output of the work vehicle 1. The display switch 76 and the one-time switch 77 are provided in the driver's seat 15. Therefore, the display switch 76 and the one-time switch 77 are switches that accept operation inputs from the occupant. The operation device 75, the display switch 76, and the one-time switch 77 are connected to the main ECU 73. The main ECU 73 has the function of controlling each part of the work vehicle 1 in response to operation inputs from the occupant. The control performed by the main ECU 73 includes control of the movement of the work vehicle 1 as well as control of the work device 335. The main ECU 73 generates control commands to be given to the inverter 62 based on the operation inputs received by the operation device 75. The inverter 62 controls the motor 31 in response to the control commands. Furthermore, when the main ECU 73 accepts operation inputs via the display switch 76, it has the function of issuing commands to the FC system ECU 71 to cause the FC display panel 72 to output the power that can be generated. That is, the display switch 76 (first operating member) and the main ECU 73 constitute an operating unit that causes the FC display panel 72 to output the possible power generation.

[0060] Furthermore, the main ECU 73 also has a function of outputting a consumption command to the FC system ECU 71 when it receives an operation input via the use-up switch 77. In other words, the use-up switch 77 (second operating member) and the main ECU 73 constitute an operating unit that outputs a consumption command to the FC system ECU 71 (control device).

[0061] The main display panel 74 is connected to the main ECU 73. The main display panel 74 displays and outputs various information indicating the status of each part of the work vehicle 1. The main display panel 74 is provided in the driver's seat 15. Therefore, the main display panel 74 outputs information to the passenger.

[0062] [Regarding the Consumption Processing] The consumption processing is executed by cooperation between the FC system ECU 71 and the main ECU 73 included in the control unit 70. FIG. 6 is a flowchart showing an example of the consumption processing. In FIG. 6, first, the main ECU 73 determines whether an operation input has been received by the display switch 76 (step S1). The main ECU 73 repeats step S1 until it determines that an operation input has been received by the display switch 76. If it determines that an operation input has been received by the display switch 76, the main ECU 73 issues a display command to the FC system ECU 71. The FC system ECU 71, upon receiving the display command, displays the current generateable power on the FC display panel 72 (step S2). Note that the main ECU 73 restricts the acceptance of an operation input from the use-up switch 77 until the current generateable power is displayed.

[0063] After the generable power is displayed, the main ECU 73 then determines whether or not an operational input has been received from the disposable switch 77 (step S3). If it is determined that an operational input has not been received from the disposable switch 77, the main ECU 73 determines whether or not a predetermined time has elapsed since the generable power was output (step S4). If it is determined that the predetermined time has not elapsed, the main ECU 73 returns to step S3 and repeats the process. If it is determined that the predetermined time has elapsed, the main ECU 73 returns to step S1. In this case, the main ECU 73 waits again for an operational input from the display switch 76 (step S1) without performing any processing after step S3. This prevents the hydrogen in the tank unit 21 from being consumed after the generable power is output, thereby preventing an increase in the difference between the displayed generable power and the actual generable power.

[0064] If it is determined in step S3 that an operation input has been received by the use-up switch 77, the main ECU 73 determines whether the amount of hydrogen in the tank unit 21 is equal to or less than the threshold value Th (step S5). As described above, the amount of hydrogen in the tank unit 21 is determined based on the output of the pressure sensor 53. Here, the threshold value Th is set to a value that is greater than the lower limit LA and less than the amount of hydrogen corresponding to the power that can be generated and the storable power of the battery unit 30. This allows the generated power to be stored in the battery unit 30 when, in later processing, the FC module 24 is caused to generate power until the amount of hydrogen in the tank unit 21 becomes equal to or less than the lower limit LA.

[0065] If it is determined in step S5 that the amount of hydrogen in the tank unit 21 is not equal to or less than the threshold value Th, the main ECU 73 ends the process. In this case, the amount of hydrogen in the tank unit 21 is not small. Therefore, the main ECU 73 stops the consumption process, which is a process that forcibly consumes hydrogen. This is because there is a risk of the hydrogen in the tank unit 21 being consumed unnecessarily.

[0066] On the other hand, if it is determined in step S5 that the amount of hydrogen in the tank unit 21 is equal to or less than the threshold value Th, the main ECU 73 outputs a consumption command to the FC system ECU 71 (step S6). As a result, the FC system ECU 71 receives the consumption command and causes the FC module 24 to start generating electricity.

[0067] The FC module 24 generates electricity using the hydrogen remaining in the tank unit 21. While the FC module 24 generates electricity, the FC system ECU 71 monitors and controls each part of the FC power generation system. The FC system ECU 71 references the state of charge (SOC) of the battery pack 30A by the BMU 30A1 and determines whether the generated power can be charged to the battery pack 30A. If it determines that the battery pack 30A can be charged, the FC system ECU 71 stores the power generated by the FC module 24 in the battery pack 30A.

[0068] When the battery pack 30A is fully charged, the FC system ECU 71 operates the first DC / DC converter 64 to convert the power generated by the FC module 24 to a first voltage and stores the power in the lead storage battery 63 and the auxiliary storage battery 67. In this way, in this embodiment, even if the battery pack 30A is fully charged, the power obtained from the hydrogen remaining in the tank unit 21 can be stored in the lead storage battery 63 and the auxiliary storage battery 67.

[0069] At this time, if an external device is connected to the external output unit 66, the power from the first DC / DC converter 64 is output to the external device. In this case, even if the battery pack 30A is fully charged, the power obtained from the hydrogen remaining in the tank unit 21 can be consumed by the external device.

[0070] When no external device is connected to the external output unit 66, the FC system ECU 71 opens the switch 63a (FIG. 4), and when an external device is connected to the external output unit 66, the FC system ECU 71 switches the switch 63a from the open state to the closed state. This makes it possible to prevent the power stored in the lead-acid battery 63 from being output to the external device. This is because the power stored in the lead-acid battery 63 is power for the auxiliary machinery of the work vehicle 1, and therefore it is undesirable for the power to be unnecessarily discharged to the outside.

[0071] When no external device is connected to the external output unit 66, the power generated by the FC module 24 is stored in the lead storage battery 63 and the auxiliary storage battery 67. When an external device is connected to the external output unit 66, the power generated by the FC module 24 and the power stored in the auxiliary storage battery 67 are output to the external device.

[0072] As described above, the power generated by the FC module 24 based on the consumption command is stored in the battery pack 30A, the lead storage battery 63, or the auxiliary storage battery 67, or is output to an external device.

[0073] Having caused the FC module 24 to start power generation based on the consumption command, the FC system ECU 71 proceeds to step S7 and repeatedly determines whether the amount of hydrogen in the tank unit 21 is equal to or less than the lower limit amount LA. If it determines that the amount of hydrogen in the tank unit 21 is equal to or less than the lower limit amount LA, the FC system ECU 71 stops power generation by the FC module 24 (step S8) and ends the process. Therefore, when the FC module 24 receives a consumption command, it generates power until the amount of hydrogen in the tank unit 21 falls below the lower limit amount (predetermined amount) LA.

[0074] According to the above configuration, when the FC system ECU 71 (control device) receives a consumption command, the FC module 24 generates electricity until the amount of hydrogen in the tank unit 21 falls below the lower limit amount LA. In other words, the FC module 24 starts generating electricity when it receives a consumption command, and stops generating electricity when the amount of hydrogen in the tank unit 21 falls below the lower limit amount LA. Therefore, for example, when the work vehicle 1 is stopped for an extended period of time, it is possible to consume the hydrogen remaining in the tank unit 21 until it falls below the lower limit amount LA, thereby reducing the amount of hydrogen in the tank unit 21 of a work vehicle 1 that is stopped for an extended period of time.

[0075] If a large amount of hydrogen remains in the tank unit 21 of a work vehicle 1 that is stopped for an extended period of time, it may not be desirable to manage the hydrogen. In this regard, according to this embodiment, the amount of hydrogen in the tank unit 21 can be reduced, and the tank unit 21 can be left empty. If the tank unit 21 is empty, there is no need to manage the hydrogen. In this way, the hydrogen remaining in the tank unit 21 can be appropriately disposed of.

[0076] In addition, the work vehicle 1 of this embodiment is further equipped with a main ECU 73 (operation unit) that outputs a consumption command to the FC system ECU 71 (step S6) when it receives an operation input via the disposable switch 77 (second operation member) (step S3), so that the FC module 24 can be made to consume the hydrogen remaining in the tank unit 21 until it falls below the lower limit amount LA by operation input from outside, such as by the passenger.

[0077] Furthermore, in this embodiment, the process of outputting a consumption command performed by the main ECU 73 to the FC system ECU 71 is executed when the amount of hydrogen in the tank unit 21 is equal to or less than the threshold value Th, in addition to receiving an operational input via the use-up switch 77. This prevents a consumption command from being output when a large amount of hydrogen remains in the tank unit 21, thereby preventing unnecessary consumption of hydrogen from the tank unit 21. In other words, if a large amount of hydrogen remains in the tank unit 21, the tank unit 21 can be removed from the work vehicle 1 and the remaining hydrogen can be stored together with the tank unit 21. In contrast, in this embodiment, when a small amount of hydrogen remains in the tank unit 21, not enough to store the entire tank unit 21, the remaining hydrogen can be consumed by the FC module 24 and used as electricity.

[0078] Therefore, the threshold value Th is set to a value that can determine a small amount of hydrogen that does not require storage in the entire tank unit 21. The threshold value Th is a value that is at least greater than the lower limit amount LA. In this case, the consumption process consumes hydrogen by the difference between the threshold value Th and the lower limit amount LA.

[0079] Furthermore, the FC system ECU 71 of this embodiment calculates the power that the FC module 24 can generate (generatable power) when hydrogen is used until the amount of hydrogen in the tank unit 21 reaches the lower limit amount LA from the current amount, and can output the amount of hydrogen in the tank unit 21 as power to the outside as needed. As a result, the amount of hydrogen in the tank unit 21 can be appropriately determined.

[0080] In this embodiment, the generateable power calculated by the FC system ECU 71 is output by the FC display panel 72 (output device). In this embodiment, when the main ECU 73 (operation unit) receives an operation input via the display switch 76 (first operation member) (step S1), it causes the FC system ECU 71 to output the generateable power by the FC display panel 72 (step S2). Thus, the generateable power can be output to the passenger in response to the passenger's request.

[0081] Furthermore, in this embodiment, the main ECU 73 outputs a consumption command to the FC system ECU 71 when it receives an operation input via the use-up switch 77 after causing the FC display panel 72 to output the generateable power, so that the occupant can determine whether or not to operate the use-up switch 77 after understanding the amount of hydrogen in the tank unit 21. As a result, the hydrogen remaining in the tank unit 21 can be disposed of more appropriately.

[0082] [Regarding the Second Embodiment] Fig. 7 is a block diagram showing an example configuration of a control unit 70 according to the second embodiment. The control unit 70 according to this embodiment differs from the control unit 70 according to the first embodiment in that it includes an automatic driving ECU 78 and a positioning device 79. The automatic driving ECU 78 has a function of executing processes necessary for automatic driving by the work vehicle 1. The automatic driving ECU 78 controls the movement of the work vehicle 1 via the main ECU 73. The automatic driving ECU 78, like the FC system ECU 71 and the main ECU 73, is connected to the CAN. Thus, the automatic driving ECU 78 can communicate with the FC system ECU 71, the main ECU 73, the electronic control unit shown in Fig. 4, and various devices.

[0083] In addition, a wireless communication device 78a and a positioning device 79 are connected to the autonomous driving ECU 78. The wireless communication device 78a performs wireless communication with a server that controls the autonomous driving of the work vehicle 1. The positioning device 79 (position detection unit) has the function of detecting the position of the host vehicle using GNSS positioning. The positioning device 79 provides the autonomous driving ECU 78 with the position of the host vehicle. The positioning device 79 is also connected to the main ECU 73, and provides the main ECU 73 with the position of the host vehicle. The autonomous driving ECU 78 obtains a work plan for the work vehicle 1 from the server. The autonomous driving ECU 78 performs autonomous driving of the work vehicle 1 based on the work plan and the position of the host vehicle. Therefore, the autonomous driving ECU 78 provides commands to the main ECU 73 in accordance with the contents of the work plan. The main ECU 73 controls the work vehicle 1 in accordance with the commands.

[0084] FIG. 8 is a flowchart showing an example of consumption processing during autonomous driving. In the consumption processing of this embodiment, the main ECU 73 determines whether the contents of the work plan indicate that the host vehicle will be stopped for a certain period of time from the current time (step S14). The main ECU 73 repeats step S14 until it determines that the contents of the work plan indicate that the host vehicle will be stopped for a certain period of time from the current time. If it determines that the contents of the work plan indicate that the host vehicle will be stopped for a certain period of time from the current time, the main ECU 73 proceeds to step S15. In FIG. 8, steps S15 to S18 are the same as steps S5 to S8 in FIG. 6. Therefore, a description thereof will be omitted here.

[0085] Thus, in this embodiment, if the contents of the work plan for the vehicle indicate that the vehicle will be stopped for a certain period of time from the present time, the main ECU 73 (planning processing unit) executes processing to output a consumption command to the FC system ECU 71 (step S16). Therefore, if it is clear that the work vehicle 1 will be stopped for a certain period of time, the hydrogen remaining in the tank unit 21 is disposed of. Therefore, the hydrogen remaining in the tank unit 21 can be appropriately disposed of without any operation by the occupant of the work vehicle 1, etc.

[0086] [Others] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. For example, the first embodiment described above illustrates a case in which the automatic driving ECU 78 and the positioning device 79 are not included, but the work vehicle 1 of the first embodiment may be equipped with a positioning device 79. In this case, the main ECU 73 may have a function to execute processing to output a command to operate the disposable switch 77 based on the position of the vehicle.

[0087] Fig. 9 is a part of a flowchart showing an example of consumption processing according to a modified example of the first embodiment. In the flowchart shown in Fig. 9, steps S11 and S12 are added between steps S2 and S3 in Fig. 6. The contents of Fig. 9 other than steps S11 and S12 are the same as those of the flowchart in Fig. 6.

[0088] In FIG. 9, when the power generation available power is displayed in step S2, the main ECU 73 determines whether the position of the host vehicle is the position of the storage location of the host vehicle (step S11). If the position of the host vehicle is not the position of the storage location of the host vehicle, the main ECU 73 proceeds to step S3. On the other hand, if the position of the host vehicle is the position of the storage location of the host vehicle, the main ECU 73 causes the main display panel 74 to output a message indicating that an operation input should be made to the exhaustion switch 77 (step S12), and then proceeds to step S3.

[0089] The main display panel 74 has a function as an output device that outputs a message indicating that an operation input should be made to the exhaustion switch 77. The modes in which the main display panel 74 outputs a message indicating that an operation input should be made include outputting a display on the panel to prompt the operation of the exhaustion switch 77, and outputting information to prompt the operation of the exhaustion switch 77 by voice notification. In this case, when there is a possibility that the work vehicle 1 is parked at the storage location and stopped for a long time, it is possible to prompt the occupant to process the hydrogen remaining in the tank unit 21.

[0090] In addition, in the first embodiment, an example was shown in which when the main ECU 73 has the display switch 76 and receives the operation input of the display switch 76 and then receives the operation input of the exhaustion switch 77, the main ECU 73 outputs a consumption command. However, the work vehicle 1 can also be configured without the display switch 76. In this case, the main ECU 73 constantly determines whether to receive the operation input of the exhaustion switch 77, and if it receives the operation input of the exhaustion switch 77, it is configured to proceed with the consumption process.

[0091] In addition, in the above embodiment, an example was shown in which the fuel of the FC module 24 is hydrogen, but the fuel of the FC module 24 may be one that generates electric power using methane or carbon monoxide. In this case, the hydrogen in the above embodiment may be replaced with methane or carbon monoxide.

[0092] The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof.

[0093] Also, the symbols used in Chapter 1 are used only in Chapter 1 and are not related to the symbols in other chapters.

[0094] [Explanation of symbols] 1 Work vehicle 11 Vehicle body 12 Traveling device 12A Front wheels 12B Rear wheels 13 Hydrogen tank 14 Drive device 15 Driver's seat 16 Cabin 17 Mounting frame 17A Ceiling frame 17B Pillar 17C Reinforcement frame 21 Tank unit 22 Piping 22A Pipe section 22B Pipe section 24 FC module 24a Fuel cell stack 24b Boost circuit 24c ECU 25 Electric circuit 30 Battery unit 30A Battery pack 31 Electric motor 32 Front frame 33 Transmission case 33a Power transmission mechanism 34 Bonnet 37 Support frame 41 Chassis 44 Coupling device 44A Upper arm 44B Lower arm 48 First radiator 49 Second radiator 50 Opening / closing valve 51 Valve unit 52 Filling port 53 Pressure sensor 54 Temperature sensor 62 Inverter 62a ECU 63 Lead storage battery 63a Switch 64 First DC / DC converter 64a ECU 65 Second DC / DC converter 65a ECU 66 External output unit 67 Auxiliary storage battery 70 Control unit 71 FC system ECU 72 FC display panel 73 Main ECU 74 Main display panel 75 Operation device 76 Display switch 77 Disposal switch 78 Automatic driving ECU 78a Wireless communication device 79 Positioning device 111 Cover 334 PTO shaft 335 Work device

[0095] <Chapter 2> Next, preferred embodiments of the present disclosure will be described in Chapter 2 with reference to the accompanying drawings. [Background Art] In recent years, in order to protect the global environment, work vehicles such as tractors have been proposed that use fuel cells that generate electricity using hydrogen instead of internal combustion engines that use fossil fuels, and that operate the travel and work devices using electric motors driven by the generated electricity. For example, Japanese Patent Laid-Open Publication No. 2023-13186 discloses a work vehicle that is equipped with a fuel cell and a hydrogen tank and generates electricity by supplying hydrogen from the hydrogen tank to the fuel cell.

[0096] [Problem to be Solved by the Present Disclosure] In a work vehicle equipped with a fuel cell, it is required that hydrogen gas released from a hydrogen tank is appropriately supplied to the fuel cell and consumed by the fuel cell. However, the work vehicle disclosed in Patent Document 1 is unable to determine whether the hydrogen gas supply status is appropriate. Therefore, the present disclosure provides a work vehicle that is able to determine the fuel supply status from the fuel tank to the fuel cell.

[0097] Effect of the Present Disclosure According to the present disclosure, in a work vehicle driven by a fuel cell, it is possible to grasp the state of fuel supply from the fuel tank to the fuel cell.

[0098] [Summary of the Embodiments] The contents of the embodiments are listed and described below. (10) A work vehicle according to the present disclosure includes a fuel cell, a fuel tank that stores fuel to be supplied to the fuel cell, a detection device that detects the state of fuel released from the fuel tank, and a control device. The control device calculates the amount of fuel released based on the state of the fuel detected by the detection device and the amount of fuel consumed in the fuel cell.

[0099] According to the above configuration, the state of fuel supply from the fuel tank to the fuel cell can be grasped using the amount of fuel released from the fuel tank and the amount of fuel consumed in the fuel cell.

[0100] (11) In the work vehicle of (10) above, the control device calculates the difference between the fuel discharge amount and the fuel consumption amount, and determines the presence or absence of an abnormality based on the difference. According to the above configuration, the difference between the fuel discharge amount and the fuel consumption amount can be used to grasp how much of the fuel discharged from the fuel tank is consumed by the fuel cell, and the presence or absence of an abnormality such as fuel leakage in the supply path can be determined.

[0101] (12) The work vehicle of (11) above includes a notification device that notifies the determination result of the presence or absence of the abnormality. According to this configuration, the user can easily recognize that an abnormality has occurred in the supply of fuel from the fuel tank to the fuel cell.

[0102] (13) The work vehicle of (10) or (11) above includes a notification device that notifies the fuel discharge amount and the fuel consumption amount. According to this configuration, based on the notified fuel discharge amount and fuel consumption amount, it is possible to easily grasp how much of the fuel discharged from the fuel tank is consumed by the fuel cell.

[0103] (14) Any one of the work vehicles of (10) to (13) above includes a plurality of the fuel tanks, and an on-off valve provided corresponding to each of the plurality of the fuel tanks and switching between the discharge of fuel from the fuel tank and the stop of the discharge. The detection device includes a pressure sensor that detects the pressure of the fuel merged from the plurality of the fuel tanks through the on-off valve, and the control device calculates the fuel discharge amount based on the pressure detected by the pressure sensor.

[0104] With this configuration, if one of the multiple on-off valves malfunctions and does not open, causing fuel to be released from only some of the fuel tanks, the pressure sensor will only detect the pressure of the fuel released from only some of the fuel tanks. In this case, the pressure drop will be greater than if the same amount of fuel were released from all of the fuel tanks. Because the amount of fuel released correlates with the detected pressure value and the volume of the fuel tanks, if the amount of fuel released is calculated based on the detected pressure value and the volume of all of the fuel tanks, a difference will occur between the calculated amount of fuel released and the amount of fuel actually released, i.e., the amount of fuel consumed by the fuel cell. Therefore, this difference can be used to determine whether a malfunction has occurred in the on-off valves.

[0105] (15) In the work vehicle of (14) above, the control device calculates the difference between the amount of fuel released and the amount of fuel consumed, determines whether or not there is an abnormality based on the difference, and closes all of the on-off valves if there is an abnormality. With this configuration, if an abnormality due to a malfunction of the on-off valves is determined, the supply of fuel from the fuel tank to the fuel cell is stopped by closing all of the on-off valves, and it is possible to prevent a state in which fuel is not being supplied appropriately from continuing.

[0106] (16) In the work vehicle of any one of (11), (12), and (15) above, the control device calculates the difference between a first integrated value obtained by integrating the fuel release amount over a predetermined period and a second integrated value obtained by integrating the fuel consumption amount over the period. According to this configuration, by integrating the fuel release amount and the fuel consumption amount over a predetermined period, it is possible to suppress the accumulation of errors and accurately grasp the supply state from the fuel tank to the fuel cell.

[0107] (17) In the work vehicle of (16) above, the control device repeatedly executes a determination process in which one cycle consists of calculating the first integrated value and the second integrated value, making the determination, and resetting the first integrated value and the second integrated value. According to the above configuration, the first and second integrated values ​​are calculated at predetermined intervals, and each time a determination is made as to whether or not an abnormality exists, the first and second integrated values ​​are reset and the determination process is repeated, thereby enabling continuous, accurate determinations to be made.

[0108] (18) In the work vehicle of (17) above, the control device determines that an abnormality exists in a single determination process as a provisional abnormality determination, and when the provisional abnormality determination is made a predetermined number of times in succession, the final provisional abnormality determination is confirmed as a formal abnormality determination. This configuration makes it possible to prevent temporary erroneous detection by the detection device from being determined to be an abnormality.

[0109] (19) The work vehicle according to any one of (10) to (18) above further comprises a pipe connecting the fuel tank and the fuel cell and allowing fuel to flow from the fuel tank to the fuel cell, the detection device including a pressure sensor connected to the pipe and detecting the pressure of the fuel flowing through the pipe, and the control device calculating the amount of released fuel based on the pressure detected by the pressure sensor. With this configuration, the amount of released fuel can be determined from the detection value of the pressure sensor provided in the pipe.

[0110] (20) The work vehicle of (19) above further includes a pressure reducing valve provided in the piping, and the pressure sensor is provided in the piping between the pressure reducing valve and the fuel tank. With this configuration, the pressure sensor can detect the pressure of the fuel before it is reduced by the pressure reducing valve, which corresponds to the pressure inside the fuel tank.

[0111] (21) In the work vehicle described in (19) or (20) above, the detection device includes a temperature sensor that detects the temperature inside the fuel tank or the temperature inside the piping, and the control device calculates the amount of released fuel based on the temperature detected by the temperature sensor. With this configuration, since the temperature of the fuel is correlated with the amount of released fuel, the amount of released fuel can be determined based on this temperature.

[0112] [Details of the embodiment] Hereinafter, details of the embodiment of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0113] [Overall Structure of Work Vehicle] Figure 10 is a perspective view of the work vehicle. Figure 11 is a right side view of the work vehicle with some exterior parts removed. As shown in Figures 10 and 11 , the work vehicle 1 is a vehicle used for agricultural work, specifically a tractor. However, the work vehicle 1 is not limited to a tractor, and may be a mobile body such as an agricultural machine, a construction machine, or a utility vehicle.

[0114] The work vehicle 1 includes a vehicle body 11, a running device 12 that supports the vehicle body 11, a driver's seat 15, and a cabin 16. The vehicle body 11 includes a chassis 41, a hood 34, a cover 111, the cabin 16, and fenders for the rear wheels 12B. Specifically, the hood 34 and the cover 111 are mounted on the chassis 41 of the vehicle body 11 in this order from the front to the rear, and the cabin 16 is disposed behind the cover 111.

[0115] The work vehicle 1 further includes a tank unit 21 having multiple tanks (fuel tanks) 13 (see FIG. 11 ) therein for storing fuel, and a drive unit 14 that is powered by the stored fuel. The fuel is liquid or gas. Examples of the fuel include hydrogen, methane, and carbon monoxide (CO). In this embodiment, the fuel is hydrogen, and each of the multiple tanks 13 is a hydrogen tank that stores hydrogen gas (also simply referred to as "hydrogen"). Therefore, the work vehicle 1 is a fuel cell vehicle (FCV), and runs on electricity generated by a chemical reaction between hydrogen and oxygen in a fuel cell 24 as its energy source. The fuel cell 24 may also generate electricity using methane or carbon monoxide.

[0116] The drive device 14 includes a fuel cell 24, a battery unit 30, and an electric motor 31 (see FIG. 12 ; hereinafter also referred to as the "motor 31"). The battery unit 30 incorporates at least one battery pack 30A (see FIG. 13 ) that stores the output power of the fuel cell 24. The work vehicle 1 has hydrogen gas piping 22. Hydrogen gas is supplied from a gas fill port 52 (see FIG. 13 ) connected to the end of the piping 22 and filled into each tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the piping 22.

[0117] The cabin 16 is a partitioned driver's compartment having front pillars, rear pillars, and a roof. The front pillars are located on the left and right sides in front of the driver's seat 15, and the rear pillars are located on the left and right sides behind the driver's seat 15. The work vehicle 1 may have a canopy or roof pegs instead of the cabin 16. The tank unit 21 is located above the driver's seat 15 and cabin 16 by a mounting frame 17, which will be described later.

[0118] The traveling device 12 is composed of front wheels 12A and rear wheels 12B, both of which are arranged symmetrically on the left and right sides of the vehicle body 11. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of a motor 31. One or both of the wheels 12A, 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers).

[0119] 11, a first radiator 48, a fuel cell 24, and a second radiator 49 are mounted in this order from front to rear on a portion of the chassis 41 corresponding to the front wheels 12A. The first radiator 48 and the fuel cell 24 are covered by the hood 34 shown in FIG. 10, and the second radiator 49 is covered by a cover 111.

[0120] 10, the top surface of the cover 111 is higher than the top edge of the hood 34 but lower than the top edge of the steering wheel of the driver's seat 15. The rear end of the hood 34 is located lower than the cover 111, and the top surface of the hood 34 is tapered from the rear end to the front end. This structure makes it difficult for the forward visibility of the operator sitting in the driver's seat 15 to be obstructed.

[0121] [Internal Structure of Work Vehicle] Figure 12 is a perspective view showing an example of the internal structure of a work vehicle. As shown in Figure 12, the chassis 41 that constitutes the vehicle body 11 is made of a steel frame that is long in the front-to-rear direction, and has a front frame 32 and a transmission case 33. The transmission case 33 is connected to the rear of the front frame 32, and the transmission case 33 and the front frame 32 form the framework of the vehicle body 11.

[0122] A mounting frame 17 for disposing the tank unit 21 above the cabin 16 is connected to the chassis 41. The mounting frame 17 includes a substantially rectangular ceiling frame 17A that is longer in the front-to-rear direction than in the left-to-right direction, a plurality of pillars 17B that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C that are connected to the front end of the ceiling frame 17A.

[0123] The tank unit 21 is connected in a horizontal position to the ceiling frame 17A. As shown in Figure 11, the ceiling frame 17A is located higher than the roof of the cabin 16. Therefore, the tank unit 21 is disposed above the roof of the cabin 16.

[0124] The reinforcing frame 17C is a reinforcing diagonal member that slopes downward from the front end of the ceiling frame 17A to the front frame 32. Therefore, the rigidity of the mounting frame 17 in the front-to-rear direction is strengthened compared to when the ceiling frame 17A and the tank unit 21 are supported only by the pillars 17B.

[0125] A support frame 37 for supporting the battery unit 30 on the vehicle body 11 is connected to the chassis 41 of the work vehicle 1. Specifically, the motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to a portion of the front frame 32 corresponding to the motor 31. The support frame 37 is made of, for example, a metal frame member, and is attached in a cantilevered state so as to protrude to the right from the front frame 32.

[0126] The transmission case 33, located rearward of the motor 31, has a power transmission mechanism therein. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and transmits the rotation of the output shaft of the motor 31 to the traveling device 12 while slowing or accelerating the rotation. The power transmission mechanism inside the transmission case 33 includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIG. 13 ). The PTO shaft 334 is an output shaft that protrudes rearward from the transmission case 33.

[0127] A coupling device 44 (see FIG. 11), which is configured, for example, by a three-point linkage mechanism, is attached to the transmission case 33 for coupling a work implement 335 (see FIG. 13; also referred to as an "implement") for performing a desired agricultural task to the rear of the vehicle body 11. The three-point linkage mechanism may be configured, for example, by an upper arm 44A that protrudes rearward from the transmission case 33 and a pair of lower arms 44B on the left and right. The work implement 335 is, for example, a cultivator or a baler.

[0128] For example, while the traveling device 12 is being driven, the rotational motion of the PTO shaft 334 is transmitted to the input shaft of the working device 335 connected to the coupling device 44. Therefore, the work vehicle 1 can drive the working device 335 with the power of the motor 31 while traveling in a field or the like.

[0129] [Functional Configuration of Work Vehicle] Fig. 13 is a block diagram showing an example of the functional configuration of a work vehicle 1. As shown in Fig. 13, the functional systems of the work vehicle 1 include a fuel system FS, a power system PS, and a temperature control system TS.

[0130] The components of the fuel system FS include at least one tank 13, valves 75-78, and sensors 81 and 82. The components of the temperature control system TS include multiple radiators 48 and 49 and an air conditioner 50. The components of the power system PS include a fuel cell 24, a boost circuit 61, an inverter 62, a motor 31, a transmission case 33, DC / DC converters 64 and 65, and a battery unit (hereinafter also referred to as the "first battery") 30.

[0131] The work vehicle 1 of this embodiment is equipped with a plurality of tanks 13, for example, three tanks 13. Each tank 13 is connected to pipes 22A and 22B. Pipe 22A is a gas pipe connecting the gas filling port 52 and each tank 13. Pipe 22A guides hydrogen gas introduced into the gas filling port 52 to each tank 13. Pipe 22A branches into multiple parts downstream, and each branch portion 22A1 is connected to each tank 13. A check valve 75 is provided in each branch portion 22A1 of pipe 22A. Each check valve 75 prevents hydrogen gas from flowing back from each tank 13 toward the gas filling port 52.

[0132] The pipe 22B is a gas pipe connecting the fuel cell 24 and the tank 13. The pipe 22B guides hydrogen gas stored in each tank 13 to the fuel cell 24. The pipe 22B branches into multiple parts upstream, and each branch portion 22B1 is connected to each tank 13. An on-off valve 76 is provided at each branch portion 22B1 of the pipe 22B. Each on-off valve 76 switches between releasing hydrogen from each tank 13 and stopping (shutting off) the release.

[0133] A pressure reducing valve 77 and a main on-off valve 78 are provided at the confluence 22B2 of the pipe 22B. The pressure reducing valve 77 reduces the pressure of the hydrogen gas released from the tank 13. The pressure of the hydrogen gas inside the tank 13 is, for example, 35 megapascals or more, whereas the pressure of the hydrogen gas after being reduced by the pressure reducing valve 77 is, for example, about 2 atmospheres. The main on-off valve 78 switches between supplying the hydrogen gas reduced by the pressure reducing valve 77 to the fuel cell 24 and stopping (shutting off) the supply.

[0134] A pressure sensor 81 is provided between the multiple on-off valves 76 and the pressure reducing valve 77. The pressure sensor 81 is provided at the confluence 22B2 of the pipe 22B. The pressure sensor 81 detects the pressure of the hydrogen gas released from the multiple tanks 13. The pressure detected by the pressure sensor 81 corresponds to the pressure of the hydrogen gas inside the tank 13 that is releasing the hydrogen gas through the on-off valve 76. In addition, each tank 13 is provided with a temperature sensor 82. The temperature sensor 82 detects the temperature of the hydrogen gas inside the tank 13. The pressure sensor 81 and the temperature sensor 82 constitute a detection device that detects the state of hydrogen (fuel).

[0135] The hydrogen gas released from the tank 13 and flowing through the pipe 22B is supplied to the fuel cell 24. The fuel cell 24 is, for example, a battery module configured by stacking a plurality of unit cells each having a positive electrode and a negative electrode side by side. The fuel cell 24 aggregates the electric power generated by each unit cell to generate the electric power required to drive the electric motor 31.

[0136] The fuel cell 24 is connected to the second radiator 49 through a cooling flow path H2. The electrodes of the fuel cell 24 are adjusted to a predetermined temperature by the coolant circulated from the second radiator 49. This allows the fuel cell 24 to maintain high power generation efficiency.

[0137] The fuel cell 24 is electrically connected to the input side of a boost circuit 61, and the output side of the boost circuit 61 is electrically connected to the DC side of an inverter 62. The boost circuit 61 increases the voltage input from the fuel cell 24 and outputs it to the inverter 62 and the battery unit 30.

[0138] The inverter 62 is electrically connected to the motor 31. The inverter 62 converts the direct current input from the boost circuit 61 into three-phase alternating current and outputs it to the motor 31. Therefore, the power generated by the fuel cell 24 is boosted and converted into alternating current and transmitted to the motor 31.

[0139] The motor 31 has a rotor and a stator with multiple coils, and drives an output shaft at a predetermined torque and rotational speed. For example, the work vehicle 1 is equipped with only one motor 31, and the output shaft of the motor 31 is coupled to the transmission case 33. A plurality of motors 31 may be equipped. For example, if two types of motors 31 are provided, one for the front wheels 12A and one for the rear wheels 12B, the power of each motor 31 can be output to the front wheels 12A and the rear wheels 12B, respectively.

[0140] The power transmission mechanism of the transmission case 33 outputs all or part of the power of the motor 31 to the traveling device 12. When operating the working device 335, the power transmission mechanism also outputs the power of the motor 31 to the PTO shaft 334.

[0141] The battery unit 30 is a power storage device that absorbs load fluctuations of the fuel cell 24. Specifically, the battery unit 30 temporarily charges with power supplied from the boost circuit 61, and discharges it under high load to supply drive power for the motor 31 to the inverter 62. The battery unit 30 includes a battery pack 30A and a monitoring unit 30B. The battery pack 30A includes at least one cell. The cell is, for example, a charge-discharge type cell such as a lithium-ion battery cell. The output voltage of the battery unit 30 is, for example, 24 V.

[0142] The monitoring unit 30B includes a processor that controls switching of the operation (charging or discharging) of the battery pack 30A and measures the state of charge (for example, SOC).

[0143] The work vehicle 1 has a plurality of electrical components that operate at a lower voltage than the motor 31. These electrical components are supplied with DC power that has been stepped down by a step-down circuit. The plurality of electrical components includes, for example, an auxiliary battery (hereinafter also referred to as the "second battery") 63, radiators 48, 49, and an air conditioning unit 50. The step-down circuit is, for example, a plurality of DC / DC converters 64, 65 (hereinafter also referred to as the "first converter 64" and the "second converter 65") that have different output voltages.

[0144] The first converter 64 steps down the DC voltage input from the boost circuit 61 to a first voltage (e.g., 12 volts) and supplies it to the auxiliary battery 63, the air conditioning device 50, etc. The second converter 65 steps down the DC voltage input from the boost circuit 61 to a second voltage (e.g., 24 volts) and supplies it to the radiators 48, 49. The inverter 62 and both converters 64, 65 are disposed in a portion of the chassis 41 corresponding to the driver's seat 15. The second voltage of the second converter 65 may be supplied to the battery unit 30.

[0145] As described above, the first radiator 48 is disposed in front of the fuel cell 24, and the second radiator 49 is disposed behind the fuel cell 24 (see FIG. 11). These radiators 48, 49 constitute a cooling system that uses a coolant (refrigerant) to cool electrical components such as the fuel cell 24, boost circuit 61, inverter 62, motor 31, and first and second converters 64, 65.

[0146] A cooling flow path H1, through which coolant is circulated by a pump 66, is connected to the first radiator 48, and the coolant is cooled by heat exchange with the external air. The first radiator 48 has a first fan 35 for promoting heat exchange with the external air. The cooling flow path H1 of the first radiator 48 cools electrical components (heat-generating components), such as the boost circuit 61, the inverter 62, the motor 31, and the first and second converters 64, 65.

[0147] A cooling flow path H2, through which coolant is circulated by a pump 67, is connected to the second radiator 49, and the coolant is cooled by heat exchange with the outside air. The second radiator 49 has a second fan 36 for promoting heat exchange with the outside air. The object to be cooled by the cooling flow path H2 of the second radiator 49 is, for example, an electrical component such as the fuel cell 24.

[0148] The auxiliary battery 63 is a power storage device that supplies power to the display, communication devices, and the like mounted in the driver's seat 15. The auxiliary battery 63 is, for example, a charge-discharge type lead-acid battery. The output voltage of the auxiliary battery (second battery) 63 is, for example, 12 V, which is lower than the output voltage (for example, 24 V) of the battery unit (first battery) 30. The auxiliary battery 63 can also be used as an auxiliary power source that supplies power to the control device 70 (described later) when the fuel cell 24 is stopped.

[0149] As shown in FIG. 13 , the work vehicle 1 further includes a control device 70. The control device 70 may be configured, for example, by an ECU (Electronic Control Unit) that communicates with various electrical components using a communication protocol such as CAN (Controller Area Network). For example, the control device 70 may include an ECU that performs overall control of the entire system, from power generation by the fuel cell 24 to power output, as well as ECUs that are involved in individual control of the fuel cell module including the fuel cell 24 and boost circuit 61, and the tank module including the tank 13 and valves 75-78. Therefore, the control device 70 performs control of the opening and closing of the valves 75-78 included in the tank module, control of the flow rate of the injector that injects hydrogen into the fuel cell 24, and obtains detection values ​​from a pressure sensor 81 and a temperature sensor 82.

[0150] The control device 70 executes supply monitoring control, for example, to monitor the supply state of hydrogen gas from the tank 13 to the fuel cell 24. Specifically, the control device 70 determines whether or not there is an abnormality in the supply state of hydrogen gas. The details of the supply monitoring control will be described below.

[0151] [Supply Monitoring and Control] Figure 14 is a graph illustrating an abnormality determination method used in hydrogen supply monitoring and control. For supply monitoring and control, the control device 70 acquires detection values ​​from the pressure sensor 81 and the temperature sensor 82, and calculates the amount of hydrogen gas released from the tank 13 based on these detection values. The pressure and temperature of hydrogen gas in the tank 13 are correlated with the amount of hydrogen gas filled. In particular, the pressure of hydrogen gas in the tank 13 decreases as the amount of hydrogen gas filled in the tank 13 decreases. In other words, the pressure of hydrogen gas in the tank 13 decreases as the amount of hydrogen gas released increases. Therefore, the amount of hydrogen gas released from the tank 13 (fuel release amount) can be determined using the pressure and temperature in the tank 13.

[0152] Specifically, the control device 70 calculates the amount of hydrogen gas filled in the tank 13 by a state equation using the volume of the tank 13, the pressure of the hydrogen gas, the temperature of the hydrogen gas, the hydrogen gas constant, a correction coefficient (such as a hydrogen compressibility coefficient), etc., and calculates the amount of hydrogen released from the decrease in the amount of filled hydrogen (the difference from the previously calculated amount of filled hydrogen). The control device 70 also integrates the amount of hydrogen released from the tank 13 over a predetermined period T. For example, in FIG. 14, the dotted line graph shows the amount of hydrogen released repeatedly integrated over one cycle, with the period T being one period. When the period T has elapsed, the control device 70 resets the integrated value of the amount of hydrogen released (second integrated value) and newly integrates the amount of hydrogen released. The period T can be, for example, 30 to 60 seconds.

[0153] Similarly, the control device 70 integrates the amount of hydrogen consumed (amount of fuel consumed) in the fuel cell 24 over a predetermined period T. In Figure 14, the amount of hydrogen consumed, integrated repeatedly over one cycle of the period T, is shown by a solid line graph. Specifically, the control device 70 integrates the flow rate (amount injected per unit time) of hydrogen gas injected from the injector into the fuel cell 24 to determine the amount of hydrogen consumed over the predetermined period T. When the period T has elapsed, the control device 70 resets the integrated amount of hydrogen consumed and newly integrates the amount of hydrogen consumed.

[0154] The control device 70 compares the integrated amount of released hydrogen with the amount of consumed hydrogen. Specifically, the control device 70 calculates the difference ΔC between the amount of released hydrogen and the amount of consumed hydrogen. If this difference ΔC exceeds a predetermined threshold value α, it means that the hydrogen gas released from the tank 13 is not being properly consumed by the fuel cell 24. For example, there is a possibility that hydrogen gas is leaking from the supply path of hydrogen gas from the tank 13 to the fuel cell 24. In addition to hydrogen gas leakage, there is also a possibility that a malfunction has occurred in the on-off valve 76. Therefore, if the difference ΔC exceeds the predetermined threshold value α, the control device 70 determines that an abnormality has occurred.

[0155] The following describes how to determine whether an abnormality is caused by a malfunction of the on-off valve 76. When generating electricity using the fuel cell 24, the control device 70 opens the on-off valves 76 corresponding to all of the tanks 13. The pressure sensors 81 detect the pressure of the hydrogen gas in all of the tanks 13, and the hydrogen release amount is calculated using the detected pressure and the volume of all of the tanks 13. However, if any of the on-off valves 76 does not open properly due to a malfunction or other reason and hydrogen is released from only some of the tanks 13, the pressure drop will be greater than if hydrogen were released from all of the tanks 13. The control device 70 calculates the hydrogen release amount assuming that hydrogen is being released from all of the tanks 13. Therefore, the calculated hydrogen release amount is greater than the actual hydrogen release amount and therefore greater than the hydrogen consumption amount in the fuel cell 24. Therefore, if the difference ΔC between the calculated hydrogen release amount and the hydrogen consumption amount exceeds the threshold α, not only a hydrogen gas leak but also a malfunction of the on-off valve 76 may be suspected. In this embodiment, the use of the pressure sensor detection value to calculate the hydrogen release amount makes it possible to determine whether an abnormality is caused by a malfunction (poor opening or closing) of the on-off valve 76.

[0156] 13 , the work vehicle 1 is equipped with an alarm device 71. The alarm device 71 is composed of a display panel such as a liquid crystal panel that displays characters and figures, an organic EL (Electro Luminescence) panel, a lamp that emits light such as an LED (Light Emitting Diode), a speaker or buzzer that emits voice or sound effects, etc. The alarm device 71 is disposed in the driver's seat 15, for example.

[0157] The alarm device 71 is controlled by the control device 70. As described above, when the difference ΔC between the amount of hydrogen released and the amount of hydrogen consumed exceeds a predetermined threshold α, the control device 70 determines that an abnormality has occurred and controls the alarm device 71 to notify the user of this. The alarm device 71 can notify information indicating an "abnormality." For example, it can display information such as "hydrogen supply abnormality," "hydrogen leak," or "valve abnormality" in text or issue audible information. Furthermore, when it is determined that an abnormality has occurred, it can light or flash a lamp. The alarm device 71 can display the calculated amount of hydrogen released and the amount of hydrogen consumed in text or issue audible information. The user can recognize that there is an abnormality in the supply state of hydrogen gas from the notification by the alarm device 71. Furthermore, based on the notification from the alarm device 71, the user can take measures to eliminate the abnormality, such as inspecting the piping 22 or the on-off valve 76 or replacing parts.

[0158] When an abnormality is confirmed, the control device 70 may close all of the on-off valves 76. This makes it possible to prevent the fuel cell 24 from being driven while hydrogen gas is leaking or a malfunction of the on-off valves 76 remains.

[0159] The control device 70 of this embodiment is configured to notify the anomaly via the alarm device 71 when it determines that an abnormality exists a predetermined number of times in succession. For example, at time t0 shown in FIG. 14 , the difference ΔC0 does not exceed the threshold value α, indicating a normal state, and at the next time t1, the difference ΔC1 exceeds the threshold value α. However, at time t1, an abnormality is not confirmed, and a "provisional" abnormality determination is made. At the next time t2, the difference ΔC2 also exceeds the threshold value α, so the control device 70 makes a "provisional" abnormality determination. Then, when "provisional" abnormality determinations have been made a predetermined number of times in succession, the control device 70 determines that the last "provisional" abnormality determination is a formal abnormality determination and confirms the abnormality.

[0160] 14, an abnormality is officially confirmed after two provisional abnormality determinations, and the abnormality is notified by the alarm device 71. In this way, by confirming an abnormality on the condition that an abnormality is determined a predetermined number of times in succession, it is possible to eliminate abnormality determinations caused by temporary malfunctions, such as temporary erroneous detection by the sensors 81 and 82 or temporary malfunction of the on-off valve 76.

[0161] 15 is a flowchart showing an example of a procedure for determining an abnormality by the control device. The above procedure for determining an abnormality will be described with reference to the flowchart in FIG. 15. In step S1, the control device 70 resets a counter n (n=0) that indicates the number of consecutive "tentative" abnormality determinations. Next, in step S2, the control device 70 resets the hydrogen consumption amount Ca and the hydrogen release amount Cb (Ca=Cb=0).

[0162] Next, in step S3, the control device 70 integrates the hydrogen consumption amount Ca and the hydrogen release amount Cb. Then, in step S4, the control device 70 determines whether a predetermined period T has elapsed since the start of integration, and if the predetermined period T has elapsed, in step S5, the control device 70 calculates the difference ΔC.

[0163] In step S6, the control device 70 determines whether the difference ΔC exceeds a predetermined threshold value α. If the determination in step S6 is negative (the difference ΔC≦threshold value α), the control device 70 returns to step S1 and performs the above steps S1 to S5 again.

[0164] If the determination in step S6 is affirmative (difference ΔC>threshold value α), the control device 70 increments the value of counter n by one in step S7. Then, in step S8, the control device 70 determines whether the value of counter n has reached the number of times N required to confirm an abnormality (n=N). If the determination in step S8 is negative, the control device 70 returns to step S2 and performs the above steps S2 to S7 again. If the determination in step S8 is positive, the control device 70 confirms an abnormality in step S9. Thereafter, in step S10, the control device 70 controls the alarm device 71 to notify the abnormality.

[0165] [Other Modifications] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of the claims and equivalents thereof.

[0166] For example, although the work vehicle 1 in the above embodiment is equipped with multiple tanks 13, it may also be equipped with a single tank 13. A plurality of pressure sensors 81 may be provided corresponding to each of the multiple tanks 13. In this case, it becomes possible to determine the hydrogen release amount for each tank 13. The control device 70 may issue an alarm via the alarm device 71 after a single abnormality determination. Furthermore, the control device 70 of the work vehicle 1 in the above embodiment calculates the hydrogen release amount based on the hydrogen detection state detected by the detection devices 81, 82 and the hydrogen consumption amount consumed in the fuel cell 24, but it may calculate the release amount of methane (methane gas) or the release amount of carbon monoxide (CO gas) instead of the hydrogen release amount, and it may calculate the consumption amount of methane (methane gas) or the consumption amount of carbon monoxide (CO gas) instead of the hydrogen consumption amount. In this case, when determining the amount of methane released or consumed, "hydrogen" described in the above embodiment should be read as "methane," and when determining the amount of carbon monoxide (CO gas) consumed, "hydrogen" described in the above embodiment should be read as "carbon monoxide."

[0167] Also, the symbols used in Chapter 2 are used only in Chapter 1 and are unrelated to the symbols in other chapters.

[0168] [Explanation of symbols] 1 Work vehicle 13 Tank (fuel tank) 22 Pipe 24 Fuel cell 70 Control device 71 Notification device 76 Opening / closing valve 77 Pressure reducing valve 81 Pressure sensor (detection device) 82 Temperature sensor (detection device)

[0169] [Additional Note] The configuration disclosed in Chapter 1 is applicable to the invention disclosed in Chapter 2. Also, the configuration disclosed in Chapter 2 is applicable to the invention disclosed in Chapter 1.

Claims

1. A work vehicle comprising a fuel cell, a hydrogen tank for storing hydrogen which is fuel for the fuel cell, a motor driven by electric power output from the fuel cell, and a control device capable of acquiring a consumption command, wherein the fuel cell generates electricity until the amount of hydrogen in the hydrogen tank becomes equal to or less than a predetermined amount when the control device acquires the consumption command.

2. The work vehicle according to claim 1, further comprising an operation unit that outputs the consumption command to the control device when receiving an operation input via an operation member.

3. The work vehicle according to claim 2, further comprising a position detection unit for detecting the position of the own vehicle, and an output device that outputs to the outside that an operation input should be made to the operation member when the position detected by the position detection unit is determined to be the position of the storage place of the own vehicle.

4. The work vehicle according to claim 2, wherein the process of outputting the consumption command to the control device by the operation unit is executed when, in addition to receiving the operation input, the amount of hydrogen in the hydrogen tank is equal to or less than a threshold value.

5. The work vehicle according to claim 4, wherein the predetermined amount is a value smaller than the threshold value of the amount of hydrogen.

6. The work vehicle according to claim 1, further comprising a plan processing unit that executes a process of outputting the consumption command to the control device when the content of the work plan of the own vehicle indicates that the own vehicle will be in a stopped state for a certain period from the current time.

7. The work vehicle according to claim 1, further comprising a power storage device for storing electric power generated by the fuel cell, wherein the electric power generated by the fuel cell when the consumption command is acquired is stored in the power storage device.

8. The work vehicle according to claim 7, further comprising an auxiliary power storage device, wherein when the power storage device is fully charged, the electric power generated by the fuel cell is stored in the auxiliary power storage device.

9. The work vehicle according to claim 7, further comprising an external output unit for outputting the electric power generated by the fuel cell to the outside, wherein when the power storage device is fully charged, the electric power generated by the fuel cell is output to an external device connected to the external output unit.

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