Work vehicle

Abstract

To provide a technique that can properly process hydrogen remaining in a hydrogen tank.SOLUTION: A work vehicle 1 includes an FC module 24, a hydrogen tank 13 for storing hydrogen as fuel for the FC module 24, a motor 31 to be driven with 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 a consumption command, the FC module 24 generates electric power until the amount of hydrogen in the hydrogen tank 13 decreases to a predetermined amount or less.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a work vehicle.

Background Art

[0002] Patent Document 1 discloses a vehicle including a motor, a fuel cell system using hydrogen as fuel, and a hydrogen tank. The fuel cell system generates electricity using hydrogen supplied from the hydrogen tank, and drives the motor with the generated electricity to make the vehicle run.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above fuel cell system may be applied to a work vehicle used for agricultural work. Work vehicles are frequently used during the work period, but are hardly used and may be maintained in a stopped state for a long time outside the work period. Here, when the work period ends and the work vehicle is stopped for a long time, hydrogen may remain in the hydrogen tank mounted on the work vehicle. Thus, when hydrogen remains in the hydrogen tank of a work vehicle that is stopped for a long time, the handling of the remaining hydrogen may become a problem. Therefore, a technique capable of appropriately treating the hydrogen remaining in the hydrogen tank is desired.

Means for Solving the Problems

[0005] The work vehicle according to the present disclosure includes a fuel cell, a hydrogen tank that stores 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. When the control device acquires the consumption command, the fuel cell generates electricity until the amount of hydrogen in the hydrogen tank becomes equal to or less than a predetermined amount.

Advantages of the Invention

[0006] According to the present disclosure, the hydrogen remaining in the hydrogen tank can be appropriately processed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0008] First, the content of the embodiment will be listed and described. [Overview of the Embodiment]

[0009] (1) The work vehicle according to the present disclosure includes a fuel cell, a hydrogen tank that stores hydrogen, which is the fuel of the fuel cell, a motor driven by the electric power output from the fuel cell, and a control device capable of acquiring a consumption command. When the control device acquires the consumption command, the fuel cell generates electricity until the hydrogen amount in the hydrogen tank becomes equal to or less than a predetermined amount.

[0010] According to the above configuration, when the control device acquires the consumption command, the fuel cell starts generating electricity and stops generating electricity when the hydrogen amount in the hydrogen tank becomes equal to or less than a predetermined amount. Therefore, for example, when the work vehicle is stopped for a long time, if the control device is made to acquire the consumption command, the hydrogen remaining in the hydrogen tank can be consumed until it becomes equal to or less than a predetermined amount, and the hydrogen amount in the hydrogen tank of the work vehicle stopped for a long time can be reduced. In this way, the hydrogen remaining in the hydrogen tank can be appropriately processed.

[0011] (2) The work vehicle according to (1) above may further include an operation unit that outputs the consumption command to the control device when receiving an operation input via an operation member. In this case, the hydrogen remaining in the hydrogen tank can be consumed by the fuel cell until it becomes equal to or less than a predetermined amount by an external operation input.

[0012] (3) The work vehicle according to (2) above may further include a position detection unit that detects 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. In this case, when the work vehicle is parked at the storage place and there is a possibility of being stopped for a long time, the treatment of the hydrogen remaining in the hydrogen tank can be urged to the passengers.

[0013] (4) In the work vehicle according to (2) or (3) above, the process of outputting the consumption command performed by the operation unit to the control device may be executed in addition to receiving the operation input when the hydrogen amount in the hydrogen tank is equal to or less than a threshold value. In this case, by appropriately setting the threshold value, it is possible to suppress the output of the consumption command when a large amount of hydrogen remains in the hydrogen tank, and to suppress the unnecessary consumption of the hydrogen in the hydrogen tank.

[0014] (5) Further, in the work vehicle of (4) above, the predetermined amount may be a value in which the hydrogen amount is smaller than the threshold value. In this case, hydrogen is consumed by only the difference between the threshold value and the predetermined amount.

[0015] (6) In any one of the work vehicles of (1) to (5) above, 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, a plan processing unit that executes a process of outputting the consumption command to the control device may be further provided. In this case, when it is clear that the work vehicle will be in a stopped state for a certain period, the hydrogen remaining in the hydrogen tank is processed. Therefore, the hydrogen remaining in the hydrogen tank can be appropriately processed without the operation of the passengers of the work vehicle or the like.

[0016] (7) In any one of the work vehicles of (1) to (6) above, when a power storage device for storing the power generated by the fuel cell is further provided, when the consumption command is acquired, the power generated by the fuel cell may be stored in the power storage device. In this case, the power obtained from the hydrogen remaining in the hydrogen tank can be stored in the power storage device.

[0017] (8) In the work vehicle of (7) above, when an auxiliary power storage device is further provided, when the power storage device is fully charged, the power generated by the fuel cell may be stored in the auxiliary power storage device. 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 by the auxiliary power storage device.

[0018] (9) Further, in the work vehicle of (7) above, when further provided with an external output unit that outputs the power generated by the fuel cell to the outside, when the power storage device is fully charged, the 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 power obtained from the hydrogen remaining in the hydrogen tank can be consumed by an external device.

[0019] Also, from another perspective, the present disclosure is a control device. This control device is a control device used for a work vehicle including a fuel cell, a hydrogen tank that stores hydrogen which is the fuel of the fuel cell, and a motor driven by the power output from the fuel cell. When the control device acquires a consumption command, it includes a processing unit that executes a process of causing the fuel cell to generate electricity until the amount of hydrogen in the hydrogen tank becomes equal to or less than a predetermined amount.

[0020] [Details of Embodiment] Hereinafter, preferred embodiments will be described with reference to the drawings. Note that at least a part of each of the embodiments described below may be arbitrarily combined.

[0021] [Overall Structure of Work Vehicle] FIG. 1 is a perspective view showing an example of the overall structure of the work vehicle 1. FIG. 2 is a right side view of the work vehicle 1 with some exterior parts (such as the bonnet 34 and the 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 moving body such as an agricultural machine, a construction machine, and a utility vehicle.

[0022] The work vehicle 1 includes a vehicle body 11, a traveling device 12 that supports the vehicle body 11, a driver's seat 15, a cabin 16, and the like. The vehicle body 11 includes a chassis 41, a bonnet 34, a cover 111, a cabin 16, and a fender for the rear wheel 12B. More specifically, on the chassis 41 of the vehicle body 11, a bonnet 34, a cover 111, and a cabin 16 are arranged in order from the front to the rear.

[0023] The work vehicle 1 further includes a tank unit 21 and a drive device 14. The tank unit 21 has a plurality of hydrogen tanks 13 (see FIG. 2) for storing fuel inside. The drive device 14 outputs a driving force by the fuel stored in the tank unit 21. The fuel is liquid or gas, such as hydrogen, methane, carbon monoxide (CO), etc. The fuel of this embodiment is hydrogen. Each of the plurality of tanks 13 stores hydrogen gas. The work vehicle 1 is a fuel cell vehicle (FCV: Fuel Cell Vehicle). The work vehicle 1 has a power generation system by fuel cells (FC power generation system). The work vehicle 1 runs using the electric power from the FC power generation system as an energy source. Note that the FC power generation system of this embodiment generates electric power by hydrogen. The FC power generation system may generate electric power by methane or carbon monoxide (CO).

[0024] 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 incorporates a battery pack 30A (see FIG. 4). The battery unit 30 accumulates the electric power output by the FC module 24. The work vehicle 1 has a hydrogen gas pipe 22. Hydrogen gas is filled into each hydrogen tank 13 from a filling port 52 (see FIG. 4) provided at the end of the pipe 22. The hydrogen in the hydrogen tank 13 is supplied to the FC module 24 through the pipe 22.

[0025] The cabin 16 is a partitioned driver's cab. The cabin 16 has front pillars, rear pillars, and a roof. The front pillars are arranged on the left and right sides in front of the driver's seat 15, and the rear pillars are arranged on the left and right sides behind the driver's seat 15. The work vehicle 1 may have a canopy or a rollover protective structure (ROPS) instead of the cabin 16. When the work vehicle 1 does not have a cabin 16, the tank unit 21 is disposed above the driver's seat 15 by a mounting frame 17 described later.

[0026] The traveling device 12 is composed of front wheels 12A and rear wheels 12B. These are all arranged symmetrically with respect to the vehicle body 11. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of the motor 31. One or both of the wheels 12A and 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (endless tracks).

[0027] As shown in FIG. 2, on the portion of the chassis 41 corresponding to the front wheels 12A, a first radiator 48, an FC module 24, and a second radiator 49 are mounted in order from the front side to the rear side. The first radiator 48 and the FC module 24 are covered by a bonnet 34. The second radiator 49 is covered by a cover 111.

[0028] As shown in FIG. 1, the upper surface of the cover 111 is higher than the uppermost end of the bonnet 34, but lower than the uppermost end of the steering of the driver's seat 15. Further, the rear end portion of the bonnet 34 is at a position lower than the cover 111, and the upper surface of the bonnet 34 is formed in a tapered shape that gradually becomes lower from the rear end portion toward the front end portion. For this reason, the structure is such that it is difficult to obstruct the forward view from the operator sitting on the driver's seat 15.

[0029] 〔Internal Structure of Work Vehicle〕 FIG. 3 is a perspective view showing an example of the internal structure of the work vehicle 1. As shown in FIG. 3, the chassis 41 constituting the vehicle body 11 has a front frame 32 and a transmission case 33. The front frame 32 is made of a steel frame having a long shape in the front-rear direction. The transmission case 33 is connected to the rear portion of the front frame 32. The skeleton of the vehicle body 11 is formed from the transmission case 33 and the front frame 32.

[0030] The mounting frame 17 is connected to the chassis 41. The mounting frame 17 is a frame for arranging the tank unit 21 above the cabin 16. The mounting frame 17 includes a ceiling frame 17A, a plurality of pillars 17B, and a pair of left and right reinforcing frames 17C. The ceiling frame 17A has a substantially rectangular shape with a longer front-rear direction than the left-right direction. The plurality of pillars 17B support the ceiling frame 17A from below. The pair of reinforcing frames 17C are provided on the left and right of the front end portion of the ceiling frame 17A.

[0031] The tank unit 21 is connected to the ceiling frame 17A in a horizontally placed state. As shown in FIG. 2, the ceiling frame 17A is located at a position higher than the roof of the cabin 16. Therefore, the tank unit 21 is arranged above the roof of the cabin 16. The reinforcing frame 17C is a reinforcing diagonal member that inclines downward from the front end portion of the ceiling frame 17A to the front frame 32. Therefore, the front-rear rigidity of the mounting frame 17 is enhanced as compared with the case where the ceiling frame 17A and the tank unit 21 are supported only by the pillars 17B.

[0032] 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, a motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to the 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 cantilever state so as to protrude to the right from the front frame 32.

[0033] The transmission case 33 located behind the motor 31 has a power transmission mechanism inside. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and decelerates or accelerates the rotation of the output shaft of the motor 31 and transmits it to the traveling device 12. In addition, the power transmission mechanism includes a branching mechanism that outputs a part of the power of the motor 31 to the PTO shaft 334 (see FIG. 4). The PTO shaft 334 is an output shaft that protrudes rearward from the transmission case 33.

[0034] An attachment device 44 (see FIG. 2), which is constituted by, for example, a three-point link mechanism, for connecting a work device 335 (see FIG. 4) for performing a desired agricultural work to the rear of the vehicle body 11 is attached to the transmission case 33. The three-point link mechanism can be constituted by, for example, an upper arm 44A that protrudes rearward from the transmission case 33 and a pair of left and right lower arms 44B. The work device 335 is, for example, a tillage tractor and a baler.

[0035] The rotational motion of the PTO shaft 334 is transmitted to the input shaft of the work device 335 connected to the attachment device 44, for example, during the driving of the traveling device 12. Therefore, the work vehicle 1 can drive the work device 335 by the power of the motor 31 while traveling in a field or the like.

[0036] 〔Regarding the power generation system of the work vehicle〕 FIG. 4 is a block diagram showing an example of the FC power generation system of the work vehicle 1. In FIG. 4, in addition to the FC power generation system, the motor 31, the traveling device 12, and the work device 335 that are driven by the electric power generated by the FC power generation system are also shown. The FC power generation system includes, in addition to the FC module 24 and the battery unit 30 included in the drive device 14, a tank unit 21, a first DC / DC converter 64, a second DC / DC converter 65, and the like.

[0037] 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 cells (single cells) are stacked. The plurality of single cells are connected in series so as to obtain a desired voltage. Hydrogen as fuel and air (oxygen) are supplied to the FC stack 24a. The FC module 24 includes a compressor and a pump (not shown) for supplying hydrogen and air to the FC stack 24a. The FC stack 24a outputs (generates) electric power by an electrochemical reaction caused by hydrogen and air.

[0038] Hydrogen supplied to the FC stack 24a is supplied through the pipe 22 as described above. As shown in FIG. 4, the pipe 22 connects the FC stack 24a and the tank unit 21. The pipe 22 has a pipe portion 22A and a pipe portion 22B. The pipe portion 22A is a gas pipe connecting the filling port 52 and the tank unit 21. The pipe portion 22A guides hydrogen introduced into the filling port 52 to the tank unit 21. The pipe portion 22B is a gas pipe connecting the FC stack 24a and the tank unit 21. The pipe portion 22B guides hydrogen stored in the tank unit 21 to the FC stack 24a. A pressure sensor 53 for obtaining the amount of hydrogen in the tank unit 21 is provided in the pipe portion 22B. Also, an on-off valve 50 is provided in the pipe portion 22B. 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.

[0039] The tank unit 21 has a valve unit 51 in addition to the plurality of hydrogen tanks 13. The plurality of hydrogen tanks 13 are connected to the valve unit 51. The valve unit 51 has a function of distributing hydrogen introduced from the filling port 52 to the plurality of hydrogen tanks 13, aggregating hydrogen from the plurality of hydrogen tanks 13, adjusting it to a predetermined flow rate, and supplying it 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 hydrogen.

[0040] 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 the subsequent stage. The ECU 24c has a function of controlling each part of the FC module 24.

[0041] A circuit 25 is connected to the output terminal of the boost circuit 24b. 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 circuit 25. The power output from the boost circuit 24b is supplied to each part via the circuit 25.

[0042] 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 supplied to the inverter 62, the first DC / DC converter 64, and the second DC / DC converter 65 via the circuit 25.

[0043] The battery pack 30A includes, in addition to a battery body including a plurality of secondary battery cells, a battery management unit (BMU) 30A1. The battery body included in the battery pack 30A is, for example, a lithium-ion battery. The rated voltage of the battery body (battery pack 30A) is several hundred volts. The BMU 30A1 has a function of monitoring and protecting the battery body. Further, the BMU 30A1 has a function of controlling the charging and discharging of the battery body and measuring the charge amount (for example, SOC).

[0044] Also, an inverter 62 is connected to the circuit 25. The inverter 62 has a function of supplying power generated by the FC power generation system to the motor 31 and controlling the rotational output of the motor 31. The inverter 62 has a function of converting the DC power supplied from the FC module 24 or the battery unit 30 into three-phase AC power. The AC power output by the inverter 62 is supplied to the motor 31. The inverter 62 controls the rotational output of the motor according to control commands and the like supplied from the control unit 70 described later. The inverter 62 has an ECU 62a. The ECU 62a has a function of controlling the circuits of the inverter 62 based on the control commands and the like.

[0045] The motor 31 outputs a rotational force by the AC power supplied from the inverter 62. The rotational force output by the motor 31 is applied to the 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. Also, when operating the work device 335, the power transmission mechanism 33a outputs part of the rotational force of the motor 31 to the work device 335.

[0046] 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 (for example, 12 volts). Connected to the output terminal of the first DC / DC converter 64 are the lead-acid battery 63, the auxiliary battery 67, the external output unit 66, as well as electrical components and accessories such as lamps of the work vehicle 1. The power output by the first DC / DC converter 64 is supplied 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 and the like from the control unit.

[0047] 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 supplied to the electrical components and accessories. An on-off switch 63a is provided between the lead-acid battery 63 and the first DC / DC converter 64. The on-off 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 the power from the first DC / DC converter 64 to the devices outside the work vehicle 1. When an external device is connected to the external output unit 66, the connected external device is supplied with the power from the first DC / DC converter 64. The auxiliary battery 67 includes secondary batteries such as lead-acid batteries and lithium-ion batteries. Similar to the lead-acid battery 63, the auxiliary battery 67 stores the power output by the first DC / DC converter 64. The auxiliary battery 67 is an auxiliary power storage device that subsidiarily stores the power generated by the FC module 24.

[0048] 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 (for example, 24 volts). At the output terminal of the second DC / DC converter 65, electrical components and accessories of the work vehicle 1 are connected in the same way as the first DC / DC converter 64. The power output by the second DC / DC converter 65 is supplied to these devices. The second DC / DC converter 65 has an ECU 65a. The ECU 65a has a function of controlling the circuit of the second DC / DC converter 65 based on commands from the control unit and the like.

[0049] As shown in FIG. 4, the work vehicle 1 further has a control unit 70. The control unit 70 has functions of controlling the FC power generation system including the FC module 24, receiving operation inputs from the passengers, and controlling the entire work vehicle 1 based on the received operation inputs.

[0050] In FIG. 4, electronic control units such as ECU24c, ECU62a, ECU64a, ECU65a, and BMU30A1 include, for example, a processor, a storage device, and an input / output interface. Also, these electronic control units are connected to each other, for example, by CAN (Controller Area Network) and can communicate with each other. Further, control unit 70 is also connected to CAN.

[0051] Devices such as the on-off valve 50, the pressure sensor 53, the temperature sensor 54, and the switch 63a are also connected to CAN. Therefore, control unit 70 can transmit control commands to these devices through CAN and receive outputs provided by these devices.

[0052] Control unit 70 has a function of executing a consumption process that forcibly consumes the hydrogen remaining in tank unit 21.

[0053] 〔Regarding control unit 70 according to the first embodiment〕 FIG. 5 is a block diagram showing a configuration example of control unit 70 according to the first embodiment. Control unit 70 includes an FC system ECU 71, an FC display panel 72, a main ECU 73, a main display panel 74, an operating device 75, a display switch 76, and an end-of-use switch 77. FC system ECU 71 and main ECU 73 are connected to CAN. Therefore, FC system ECU 71 and main ECU 73 can communicate with each other with the electronic control units and various devices shown in FIG. 4.

[0054] The FC system ECU 71 and the main ECU 73 include, for example, a processor (processing unit), a storage device, and an input / output interface. The processor includes a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc. The storage device includes, for example, a flash memory, a hard disk, a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The storage device stores a computer program to be executed by the processor and necessary information. The processor realizes various processing functions it has by executing a computer program stored in a computer-readable non-transitory recording medium such as the storage device.

[0055] The FC system ECU 71 has a function of controlling an FC power generation system including the FC module 24. Also, when the FC system ECU 71 acquires a consumption command, it has a function as a control device that causes the FC module 24 to generate power until the hydrogen amount in the tank unit 21 becomes equal to or less than the lower limit amount (predetermined amount) LA. The consumption command is a command to cause the FC module 24 to generate power until the hydrogen amount in the tank unit 21 becomes equal to or less than the lower limit amount LA. Furthermore, the FC system ECU 71 also has a function of calculating the power that the FC module 24 can generate (generable power) when hydrogen is used until the hydrogen amount in the tank unit 21 becomes equal to or less than the lower limit amount LA from the current amount. Note that the lower limit amount LA is an amount at which it can be determined that the hydrogen in the tank unit 21 is almost used up and an amount at which it can be determined that the inside of the tank unit 21 is almost empty.

[0056] The FC system ECU 71 determines the available power generation 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 associating the output of the pressure sensor 53 (or the hydrogen amount in the tank unit 21), the output of the temperature sensor 54 (or the temperature), and the available power generation. When the FC system ECU 71 acquires the output of the pressure sensor 53 and the output of the temperature sensor 54, it refers to the said database to determine the available power generation. The FC system ECU 71 may determine the available power generation using the output of the pressure sensor 53, or may determine the available power generation using the hydrogen amount in the tank unit 21 obtained from the output of the pressure sensor 53. The FC system ECU 71 may constantly determine the available power generation, or may determine the available power generation when there is a need to output it.

[0057] 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 state of the FC power generation system. Also, the FC display panel 72 has a function as an output device that outputs the available power generation. The FC display panel 72 can output the available power generation by displaying a numerical value on the panel or by voice notification. The FC display panel 72 is provided at the driver's seat 15. Therefore, the FC display panel 72 outputs the available power generation to the passengers.

[0058] The operating device 75 includes an operating member for adjusting the output of the work vehicle 1 such as an accelerator pedal or an accelerator lever. The display switch 76 and the exhaustion switch 77 are provided at the driver's seat 15. Therefore, the display switch 76 and the exhaustion switch 77 are switches that receive operation inputs from the passengers. The operating device 75, the display switch 76, and the exhaustion switch 77 are connected to the main ECU 73. The main ECU 73 has a function of controlling each part of the work vehicle 1 in response to an operation input by the occupant. The control performed by the main ECU 73 includes control related to the movement of the work vehicle 1 and control related to the work device 335. The main ECU 73 generates a control command to be given to the inverter 62 based on the operation input received by the operation device 75. The inverter 62 controls the motor 31 according to the control command. In addition, when the main ECU 73 receives an operation input via the display switch 76, it has a function of giving an instruction to the FC system ECU 71 to output the generable power to the FC display panel 72. That is, the display switch 76 (the first operation member) and the main ECU 73 constitute an operation unit for outputting the generable power to the FC display panel 72.

[0059] Furthermore, when the main ECU 73 receives an operation input via the usage end switch 77, it also has a function of outputting a consumption command to the FC system ECU 71. That is, the usage end switch 77 (the second operation member) and the main ECU 73 constitute an operation unit for outputting the consumption command to the FC system ECU 71 (the control device).

[0060] The main display panel 74 is connected to the main ECU 73. The main display panel 74 displays and outputs various information indicating the states 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 toward the occupant.

[0061] 〔Regarding consumption processing〕 The consumption processing is executed by the cooperation of 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. When it is determined that an operation input has been received by the display switch 76, the main ECU 73 gives a display command to the FC system ECU 71. The FC system ECU 71, to which the display command has been given, displays and outputs the current available power on the FC display panel 72 (step S2). Note that the main ECU 73 restricts acceptance of operation inputs of the depletion switch 77 until the current available power is displayed and output.

[0062] When the available power is displayed and output, next, the main ECU 73 determines whether an operation input has been received by the depletion switch 77 (step S3). When it is determined that no operation input has been received by the depletion switch 77, the main ECU 73 determines whether a predetermined time has elapsed since the available power was output (step S4). When it is determined that the predetermined time has not elapsed, the main ECU 73 returns to step S3 and repeats the process. When 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 operation input by the display switch 76 without performing the processes after step S3 (step S1). Thereby, after outputting the available power, consumption of hydrogen in the tank unit 21 can be suppressed, and an increase in the difference between the displayed available power and the actual available power can be suppressed.

[0063] When it is determined in step S3 that an operation input has been received by the depletion switch 77, the main ECU 73 determines whether the hydrogen amount in the tank unit 21 is equal to or less than the threshold Th (step S5). The hydrogen amount in the tank unit 21 is obtained based on the output of the pressure sensor 53 as described above. Here, the threshold Th is set to a value that is greater than the lower limit amount LA and less than the amount of hydrogen corresponding to the power generation-capable power according to the power storage-capable power of the battery unit 30. As a result, in a later process, when power is generated by the FC module 24 until the amount of hydrogen in the tank unit 21 becomes equal to or less than the lower limit amount LA, the generated power can be stored in the battery unit 30.

[0064] If it is determined in step S5 that the amount of hydrogen in the tank unit 21 is not less than the threshold 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 aborts the consumption process, which is a process of forcibly consuming hydrogen, because there is a risk of consuming hydrogen in the tank unit 21 unnecessarily.

[0065] On the other hand, if it is determined in step S5 that the amount of hydrogen in the tank unit 21 is less than or equal to the threshold Th, the main ECU 73 outputs a consumption command to the FC system ECU 71 (step S6). Thereby, the FC system ECU 71 acquires the consumption command and starts power generation in the FC module 24.

[0066] The FC module 24 generates power using the hydrogen remaining in the tank unit 21. While the FC module 24 is generating power, the FC system ECU 71 monitors and controls each part of the FC power generation system. The FC system ECU 71 refers to 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 is determined 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.

[0067] 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 the first voltage and stores it in the lead-acid battery 63 and the auxiliary storage battery 67. Thus, in this embodiment, even when 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.

[0068] 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 when 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.

[0069] Note that when no external device is connected to the external output unit 66, the FC system ECU 71 keeps the switch 63a (Fig. 4) open, 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. Thus, it is possible to suppress the power stored in the lead storage battery 63 from being output to the external device. This is because the power stored in the lead storage battery 63 is for the auxiliary equipment of the work vehicle 1, and it is not preferable to wastefully discharge it to the outside.

[0070] 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. Also, 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.

[0071] 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, and the auxiliary storage battery 67, or output to the external device.

[0072] The FC system ECU 71 that has started power generation in the FC module 24 based on the consumption command proceeds to step S7 and repeatedly determines whether or not the hydrogen amount in the tank unit 21 is equal to or less than the lower limit LA. When it is determined that the amount of hydrogen in the tank unit 21 is equal to or less than the lower limit LA, the FC system ECU 71 stops the power generation by the FC module 24 (step S8) and ends the process. Therefore, when the FC module 24 acquires a consumption command, the FC module 24 generates power until the amount of hydrogen in the tank unit 21 becomes equal to or less than the lower limit (predetermined amount) LA.

[0073] According to the above configuration, when the FC system ECU 71 (control device) acquires a consumption command, the FC module 24 generates power until the amount of hydrogen in the tank unit 21 becomes equal to or less than the lower limit LA. In other words, when the FC module 24 acquires a consumption command, it starts generating power, and when the amount of hydrogen in the tank unit 21 becomes equal to or less than the lower limit LA, it stops generating power. For this reason, for example, when the work vehicle 1 is stopped for a long period of time, the hydrogen remaining in the tank unit 21 can be consumed until it becomes equal to or less than the lower limit LA, and the amount of hydrogen in the tank unit 21 of the work vehicle 1 that is stopped for a long period of time can be reduced.

[0074] When a large amount of hydrogen remains in the tank unit 21 of the work vehicle 1 that is stopped for a long period of time, it may not be preferable in terms of hydrogen management. In this regard, according to the present embodiment, the amount of hydrogen in the tank unit 21 can be reduced, and the tank unit 21 can be made empty. If the tank unit 21 is in an empty state, there is no need to manage hydrogen. In this way, the hydrogen remaining in the tank unit 21 can be appropriately processed.

[0075] Further, the work vehicle 1 of the present embodiment further includes a main ECU 73 (operation unit) that outputs a consumption command to the FC system ECU 71 (step S6) when receiving an operation input via a use-up switch 77 (second operation member) (step S3). Therefore, the hydrogen remaining in the tank unit 21 can be consumed by the FC module 24 until it becomes equal to or less than the lower limit LA by an operation input from the outside such as a passenger.

[0076] In addition, in this embodiment, the process of outputting the consumption command performed by the main ECU 73 to the FC system ECU 71 is executed when, in addition to receiving an operation input via the depletion switch 77, the amount of hydrogen in the tank unit 21 is equal to or less than the threshold value Th. Therefore, it is possible to suppress the output of a consumption command when a large amount of hydrogen remains in the tank unit 21, and to suppress the unnecessary consumption of hydrogen in the tank unit 21. That is, 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. On the other hand, in this embodiment, when a small amount of hydrogen that is not enough to be stored together with the tank unit 21 remains in the tank unit 21, the remaining hydrogen can be consumed by the FC module 24 and used as electric power.

[0077] Therefore, the threshold value Th is set to a value that can determine a small amount of hydrogen that is not enough to be stored together with the tank unit 21. The threshold value Th is at least a value greater than the lower limit amount LA. In this case, by the consumption process, hydrogen is consumed by the difference between the threshold value Th and the lower limit amount LA.

[0078] In addition, the FC system ECU 71 of this embodiment calculates the electric power (generable electric power) that the FC module 24 can generate when hydrogen is used until the amount of hydrogen in the tank unit 21 reaches the lower limit amount LA from the current amount. Therefore, if necessary, the amount of hydrogen in the tank unit 21 can be output to the outside as electric power. As a result, it becomes possible to appropriately grasp the amount of hydrogen in the tank unit 21.

[0079] In this embodiment, the generable electric 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 generable power by the FC display panel 72 (step S2). Therefore, the generable power can be output to the occupant according to the request of the occupant.

[0080] Also, after the main ECU 73 of this embodiment causes the FC display panel 72 to output the generable power, when it receives an operation input via the exhaustion switch 77, it outputs a consumption command to the FC system ECU 71. Therefore, after allowing the occupant to grasp the hydrogen amount in the tank unit 21, the occupant can be made to determine whether or not to operate the exhaustion switch 77. As a result, the remaining hydrogen in the tank unit 21 can be processed more appropriately.

[0081] 〔Regarding the second embodiment〕 FIG. 7 is a block diagram showing a configuration example of the control unit 70 according to the second embodiment. The control unit 70 of this embodiment is different from the control unit 70 of 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 the automatic driving of 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 is connected to the CAN, similar to the FC system ECU 71 and the main ECU 73. Therefore, the automatic driving ECU 78 can communicate with the FC system ECU 71, the main ECU 73, the electronic control units shown in FIG. 4, and various devices.

[0082] Also, a wireless communication device 78a and a positioning device 79 are connected to the automatic driving ECU 78. The wireless communication device 78a performs wireless communication with a server that controls the automatic driving of the work vehicle 1. The positioning device 79 (position detection unit) has a function of detecting the position of the host vehicle by GNSS positioning. The positioning device 79 provides the position of the host vehicle to the automatic driving ECU 78. Further, the positioning device 79 is also connected to the main ECU 73 and provides the position of the host vehicle to the main ECU 73 as well. The automatic driving ECU 78 acquires the work plan of the work vehicle 1 from the server. The automatic driving ECU 78 executes the automatic driving of the work vehicle 1 based on the work plan and the position of the host vehicle. Therefore, the automatic driving ECU 78 gives an instruction according to the content of the work plan to the main ECU 73. The main ECU 73 controls the work vehicle 1 according to the instruction.

[0083] Figure 8 is a flowchart showing an example of the consumption process during automatic driving execution. In the consumption process of the present embodiment, the main ECU 73 determines whether the content of the work plan indicates that the host vehicle is to be stopped for a certain period from the current time (step S14). The main ECU 73 repeats step S14 until it determines that the content of the work plan indicates that the host vehicle is to be stopped for a certain period from the current time. When it is determined that the content of the work plan indicates that the host vehicle is to be stopped for a certain period from the current time, the main ECU 73 proceeds to step S15. In Figure 8, steps S15 to S18 are the same as steps S5 to S8 in Figure 6. Therefore, the description is omitted here.

[0084] Thus, in the present embodiment, when the content of the work plan of the host vehicle indicates that the host vehicle is to be stopped for a certain period from the current time, the main ECU 73 (planning processing unit) executes a process of outputting a consumption command to the FC system ECU 71 (step S16). Therefore, when it is clear that the work vehicle 1 is to be stopped for a certain period, the hydrogen remaining in the tank unit 21 is processed. Therefore, the hydrogen remaining in the tank unit 21 can be appropriately processed without the operation of the passengers etc. of the work vehicle 1.

[0085] 〔Others〕 It should be considered that all the embodiments disclosed this time are illustrative and not restrictive in any way. For example, in the above first embodiment, the case where the automatic driving ECU 78 and the positioning device 79 are not provided is illustrated. However, the work vehicle 1 of the first embodiment may be provided with the positioning device 79. In this case, the main ECU 73 may have a function of executing a process of outputting an instruction to perform an operation input to the exhaustion switch 77 based on the position of the own vehicle.

[0086] 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 step S2 and step S3 in FIG. 6. The contents other than steps S11 and S12 in FIG. 9 are the same as the flowchart in FIG. 6.

[0087] In FIG. 9, when the generable power is displayed in step S2, the main ECU 73 determines whether the position of the own vehicle is the position of the storage place of the own vehicle (step S11). When the position of the own vehicle is not the position of the storage place of the own vehicle, the main ECU 73 proceeds to step S3. On the other hand, when the position of the own vehicle is the position of the storage place of the own vehicle, the main ECU 73 outputs an instruction to perform an operation input to the exhaustion switch 77 to the main display panel 74 (step S12), and proceeds to step S3.

[0088] The main display panel 74 has a function as an output device that outputs an instruction to perform an operation input to the exhaustion switch 77. When the main display panel 74 outputs an instruction to perform an operation input, the modes include outputting a display prompting the operation of the exhaustion switch 77 on the panel, and outputting information prompting the operation of the exhaustion switch 77 by voice notification. In this case, when the work vehicle 1 may be parked at a storage location and stopped for a long period of time, it is possible to prompt the passenger to process the hydrogen remaining in the tank unit 21.

[0089] Further, in the above-described first embodiment, an example is given in which when the display switch 76 is provided and the operation input of the display switch 76 is received and then the operation input of the depletion switch 77 is received, the main ECU 73 outputs a consumption command. However, the work vehicle 1 may be configured without including the display switch 76. In this case, the main ECU 73 is configured to constantly determine whether the operation input of the depletion switch 77 is received, and if the operation input of the depletion switch 77 is received, the consumption process is advanced.

[0090] Also, in the above embodiment, the case where the fuel of the FC module 24 is hydrogen is exemplified, 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.

[0091] The scope of the present invention is not as described above, but is indicated by the scope of the claims, and it is intended that meanings equivalent to the scope of the claims and all modifications within the scope are included.

Explanation of Reference Numerals

[0092] 1 Work vehicle 11 Vehicle body 12 Traveling device 12A Front wheel 12B Rear wheel 13 Hydrogen tank 14 Driving device 15 Driver's seat 16 Cabin 17 Mounting frame 17A Ceiling frame 17B Pillar 17C Reinforcing frame 21 Tank unit 22 Pipe 22A Pipe portion 22B Pipe section 24 FC module 24a Fuel cell stack 24b Boost circuit 24c ECU 25 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 Connecting device 44A Upper arm 44B Lower arm 48 First radiator 49 Second radiator 50 On-off valve 51 Valve unit 52 Filling port 53 Pressure sensor 54 Temperature sensor 62 Inverter 62a ECU 63 Lead-acid battery 63a Switch 64 First DC / DC converter 64a ECU 65 Second DC / DC converter 65a ECU 66 External output section 67 Auxiliary storage battery 70 Control unit 71 FC system ECU 72 FC display panel 73 Main ECU 74 Main display panel 75 Operating device 76 Display switch 77 Exhaustion switch 78 Autopilot ECU 78a Wireless communication device 79 Positioning device 111 Cover 334 PTO shaft 335 Working device

Claims

1. A fuel cell, a hydrogen tank for storing hydrogen, which is the fuel of the fuel cell, a motor driven by the 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 a work vehicle.

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 a message indicating 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 receiving the operation input and when 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 the electric power generated by the fuel cell, wherein the electric power generated by the fuel cell when acquiring the consumption command 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. ​ ​ ​ ​ ​ ​ ​

Images