Work vehicle

Abstract

This work vehicle comprises: a fuel cell; a hydrogen tank that accommodates hydrogen to be supplied to the fuel cell; a sensor that detects the state of hydrogen in the hydrogen tank; and a notification device that provides notification of information corresponding to a detection value from the sensor.

Description

Work vehicles

[0001] This disclosure relates to a fuel cell-powered work vehicle. This application claims priority to Japanese Patent Application No. 2023-219038, filed December 26, 2023, and incorporates by reference all of the contents of said Japanese application.

[0002] In order to protect the global environment, it has been proposed to replace fossil-fuel-powered internal combustion engines in work vehicles such as tractors with fuel cells that generate electricity using hydrogen gas, and to operate the travel and work equipment using electric motors driven by the generated electricity (see Patent Document 1). Patent Document 2 also discloses a vehicle equipped with a fuel cell and a gas tank, and a gas station equipped with a gas filling system. This technology enables a gas station control device to fill the gas tank with gas based on information received from a vehicle control device and a filling protocol previously installed in the gas station control device, thereby enabling the gas tank to be filled appropriately.

[0003] JP 2023-13186 A JP 2011-33068 A

[0004] The work vehicle of the present disclosure comprises a fuel cell, a hydrogen tank that stores hydrogen to be supplied to the fuel cell, a sensor that detects the state of hydrogen in the hydrogen tank, and an alarm device that reports information according to the detection value of the sensor.

[0005] FIG. 1 is a perspective view of a work vehicle. FIG. 2 is a front view of the work vehicle. FIG. 3 is a rear view of the work vehicle. FIG. 4 is a right side view of the work vehicle. FIG. 5 is a left side view of the work vehicle. FIG. 6 is a plan view of the work vehicle. FIG. 7 is a perspective view showing an example of the internal structure of a work vehicle. FIG. 8 is a perspective view showing the area around the filling port of the work vehicle. FIG. 9 is a block diagram showing an example of the functional configuration of a work vehicle. FIG. 10 is a flowchart showing the control procedure for filling monitoring control.

[0006] <Problem to be Solved by the Present Disclosure> The technology described in Patent Document 2 fills a gas tank with gas according to a filling protocol set by the gas station, so that an appropriate amount of gas can be filled into the gas tank in a short time without the vehicle needing to know the filling status. However, because communication between the vehicle and the gas station is required, this technology cannot be applied to vehicles or gas stations that do not have communication capabilities. In particular, work vehicles such as those described in Patent Document 1, unlike passenger cars that run on public roads, are likely to be filled at simple gas stations installed in fields, etc., rather than at fully equipped gas stations, and there is a high possibility that communication between the vehicle and the gas station will not be possible.

[0007] An object of the present disclosure is to provide a work vehicle that allows the fill state of a fuel tank to be known from the work vehicle side.

[0008] Effect of the Present Disclosure According to the present disclosure, in a work vehicle driven by a fuel cell, the state of filling of the fuel tank can be grasped on the work vehicle side.

[0009] <Outline of Embodiments of the Present Disclosure> The following is a list and description of outlines of embodiments of the present disclosure: (1) A work vehicle according to this embodiment includes a fuel cell, a hydrogen tank that stores hydrogen to be supplied to the fuel cell, a sensor that detects the state of hydrogen in the hydrogen tank, and a notification device that notifies information according to the detection value of the sensor.

[0010] When hydrogen is filled into a hydrogen tank, the state of the hydrogen inside the hydrogen tank, such as temperature and pressure, fluctuates. Therefore, it is possible to detect any abnormalities in the filling process based on the state of the hydrogen. In the work vehicle according to the above embodiment, the sensor detects the state of the hydrogen while the hydrogen tank is being filled, and the alarm device reports information corresponding to the detected value. This allows the work vehicle to monitor the filling status without communicating with a gas station.

[0011] (2) The work vehicle described in (1) above is equipped with a fill port for filling the hydrogen tank with hydrogen, and the alarm device is disposed near the fill port. With this configuration, people near the fill port, such as the person filling hydrogen through the fill port (filler), can easily check the content of the alarm device's notification.

[0012] (3) The work vehicle of (1) or (2) above is equipped with a filling port for filling the hydrogen tank with hydrogen, and the notification device is a display device that is located within the field of view of the filling port when viewed from a predetermined direction. With this configuration, people near the filling port, such as a filler, can easily check the notification content displayed on the display device.

[0013] (4) The work vehicle according to any one of (1) to (3) above is provided with a driver's seat, and the notification device is disposed outside the driver's seat. With this configuration, a person outside the driver's seat, such as a person filling the tank, can easily check the notification content of the notification device.

[0014] (5) The work vehicle of (4) above includes a cabin surrounding the driver's seat, and the alarm device is disposed outside the cabin.

[0015] This configuration makes it easier for people outside the cabin, such as the person filling the hydrogen filling port (filler), to check the content of the notification from the notification device.

[0016] (6) In the work vehicle described in any one of (1) to (5) above, the notification device notifies the presence or absence of a filling abnormality obtained from the detection value.

[0017] According to this configuration, the notification device can directly inform the user whether or not there is an abnormality in the hydrogen filling.

[0018] (7) The work vehicle described in (6) above is equipped with a control device that determines whether or not there is a filling abnormality based on the detection value of the sensor.

[0019] (8) In the work vehicle of (7) above, the control device determines that an abnormality exists when the detection value of the sensor exceeds a predetermined threshold value.

[0020] (9) In the work vehicle described in (7) or (8) above, the control device stops the filling of hydrogen into the hydrogen tank based on the determination that an abnormality exists.

[0021] According to the above configuration, it is possible to suppress the occurrence of problems due to abnormal filling.

[0022] (10) In the work vehicle according to any one of (1) to (9), the notification device notifies the detected value. According to the above configuration, the state of hydrogen can be directly known.

[0023] (11) In the work vehicle described in any one of (1) to (10) above, the sensor is a temperature sensor. This configuration makes it possible to obtain information corresponding to the temperature during hydrogen filling. For example, if the hydrogen temperature rises excessively during hydrogen filling, it becomes possible to take measures such as stopping filling before the temperature exceeds the allowable temperature of the hydrogen tank. In particular, the temperature inside the hydrogen tank cannot be obtained by a hydrogen gas supply device at a gas station, etc., and even if communication with the hydrogen gas supply device is possible, it is not possible to obtain information such as temperature abnormalities. In this respect, the configuration of the above embodiment (11) is more effective.

[0024] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. [Overall Structure of Work Vehicle] FIG. 1 is a perspective view of a work vehicle. FIG. 2 is a front view of the work vehicle. FIG. 3 is a rear view of the work vehicle. FIG. 4 is a right side view of the work vehicle. FIG. 5 is a left side view of the work vehicle. FIG. 6 is a plan view of the work vehicle. Note that in this specification, the direction in which the work vehicle 1 moves forward is defined as "front," the direction in which the work vehicle 1 moves backward is defined as "rear," the left side of the work vehicle 1 when facing forward is defined as "left," and the right side of the work vehicle 1 when facing forward is defined as "right." In FIGS. 1 to 7, the forward, backward, left, right, up, and down directions are indicated by arrows X1, X2, Y1, Y2, Z1, and Z2, respectively. As shown in FIGS. 1 to 6, 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 object such as agricultural machinery, construction machinery, or a utility vehicle.

[0025] 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 a fender 47 for the rear wheel 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.

[0026] The work vehicle 1 further includes a tank unit 21 having multiple tanks 13 (see FIG. 2) for storing fuel, and a drive unit 14 that is powered by the stored fuel. The tank unit 21 includes a rectangular parallelepiped case 21A whose vertical length (height) is smaller than its longitudinal and transverse lengths, and the multiple tanks 13 are housed side by side within this case 21A. The tank unit 21 includes various valves 74 to 78 (see FIG. 9). The tank unit 21 is disposed above the driver's seat 15 and cabin 16 by a mounting frame 17.

[0027] The fuel is hydrogen, and each of the tanks 13 is a hydrogen tank that stores hydrogen gas. 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 the fuel cell 24 as its energy source. The fuel cell 24 is also called a "hydrogen cell."

[0028] The drive device 14 includes a fuel cell 24, a battery unit 30, and an electric motor 31 (see FIG. 4; hereinafter, also referred to as the "motor 31"). The battery unit 30 incorporates at least one battery pack 30A (see FIG. 9) that stores the output power of the fuel cell 24.

[0029] The work vehicle 1 has a hydrogen gas pipe 22 and a filling unit 25. The filling unit 25 has a filling port (receptacle) 26 to which a filling nozzle 401 of a hydrogen gas supply device 400 (see FIG. 9 ) at a gas station or the like that is separate from the work vehicle 1 is connected. Hydrogen gas is supplied from the filling port 26 and supplied to the tank 13 through the pipe 22. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22. The specific configurations of the filling unit 25 and the pipe 22 will be described later.

[0030] The cabin 16 is a partitioned driver's compartment with front pillars, rear pillars, and a roof, and surrounds the driver's seat 15. The driver's seat 15 includes a seat 15A and a control device 15B. The control device 15B includes a steering wheel, levers, instruments, etc. The front pillars of the cabin 16 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 cabin 16 includes a front panel 165 (see FIG. 2) between the left and right front pillars, a rear panel 161 (see FIG. 3) between the left and right rear pillars, and side panels 166 between the front and rear pillars. The side panels 166 include openable and closable doors. The front panel 165, rear panel 161, and side panels 166 are formed of transparent materials such as glass or synthetic resin, allowing the outside of the cabin 16 to be seen from inside and the inside from outside. The work vehicle 1 may include a canopy or roof hood instead of the cabin 16.

[0031] 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 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). The upper and front of the rear wheels 12B are covered by fenders 47.

[0032] 4 and 5, 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, and the second radiator 49 is covered by a cover 111.

[0033] 4, the upper surface 111a of the cover 111 is higher than the top of the hood 34 but lower than the top of the steering wheel 15B of the driver's seat 15. The rear end of the hood 34 is located lower than the cover 111, and the upper surface 34a 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.

[0034] [Internal Structure of Work Vehicle] Figure 7 is a perspective view showing an example of the internal structure of a work vehicle. As shown in Figure 7, 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.

[0035] 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. The mounting frame 17 also includes a base frame 17D to which the lower ends of the rear left and right pillars 17B are connected, and a pair of left and right lower frames 17E that extend downward from the base frame. The base frame 17D is positioned approximately horizontally and extends in the left-to-right direction.

[0036] A tank unit 21 is connected in a horizontal position to the ceiling frame 17A. As shown in Figure 3, 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.

[0037] 7, 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 increased compared to when the ceiling frame 17A and the tank unit 21 are supported only by the pillars 17B.

[0038] 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.

[0039] 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. 9). The PTO shaft 334 is an output shaft that protrudes rearward from the transmission case 33.

[0040] A coupling device 44 (see FIG. 6), which is configured by, for example, a three-point linkage mechanism, is attached to the transmission case 33 to couple a work implement 335 (see FIG. 9, also called an "implement") for performing a desired agricultural task to the rear of the vehicle body 11. The work implement 335 is, for example, a cultivator or a baler.

[0041] 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.

[0042] 8 is a perspective view showing the area around the filling port of the work vehicle. The filling unit 25 has a housing 28 that houses the filling port 26. The housing 28 has a case 28a and a lid 28b. The case 28a has walls on the top, bottom, left, right, and front, and opens to the rear. The lid 28b is openable and can close the opening of the case 28a. The filling port 26 is provided on the housing 28 so as to open to the rear or side of the vehicle. The piping 22A is connected to the filling unit 25 (filling port 26) from the front of the housing 28.

[0043] With this configuration, filling port 26 is protected by housing 28. Pipe 22A is connected to filling section 25 from the space formed between housing 28 and the rear of vehicle body 11. Connection section 29 between pipe 22A and housing 28 is not exposed to the wide space behind the vehicle, and connection section 29 is protected.

[0044] In this embodiment, the filling section 25 (filling port 26) is located behind the cabin 16 and between the rear wheels 12B on both sides in the vehicle width direction. The filling section 25 (filling port 26) is protected from the left and right by the rear wheels 12B and from the front by the cabin 16.

[0045] The filling section 25 (filling port 26) is disposed below the base frame 17D of the mounting frame 17. The filling section 25 (filling port 26) is supported on the base frame 17D via brackets 27. The filling section 25 (filling port 26) is protected from above by the base frame 17D. The filling section 25 (filling port 26) is disposed between the left and right lower frames 17E.

[0046] An alarm device 71 is provided on the base frame 17D. As will be described later, the alarm device 71 provides information according to the state of hydrogen in the tank 13. The alarm device 71 is disposed below the base frame 17D. The alarm device 71 is disposed adjacent to the filling section 25 (filling port 26). The alarm device 71 is disposed adjacent to the filling section 25 in the left-right direction. Therefore, when the work vehicle 1 is viewed from the rear, the filling section 25 and the alarm device 71 are within sight. Therefore, a person (filler) performing the hydrogen gas filling work through the filling port 26 can easily see the alarm device 71. The alarm device 71 is disposed outside the driver's seat 15, specifically outside the cabin 16. Therefore, a person outside the cabin 16 can easily see the alarm device 71.

[0047] The notification device 71 of this embodiment is a display device. The display device is a display panel such as a liquid crystal panel or an organic EL (Electro Luminescence) panel that displays characters and figures. The display surface of the notification device 71 faces backward. The notification device 71 is not limited to a display device, and may be configured with a lamp such as an LED (Light Emitting Diode) that emits light, or a speaker or buzzer that emits voice or sound effects. If the notification device 71 is a speaker or buzzer, even a person who is far from the notification device 71 can confirm the notification. The notification device 71 may be configured with two or more of a display panel, a lamp, a speaker, and a buzzer.

[0048] The notification device 71 is controlled by the control device 70, which will be described later. Under the control of the control device 70, the notification device 71 notifies information according to the state of the hydrogen gas in the tank 13. In particular, the notification device 71 notifies information according to the state of the hydrogen gas being filled into the tank 13. The control of the control device 70 and the notification device 71 will be described later.

[0049] [Functional Configuration of Work Vehicle] Fig. 9 is a block diagram showing an example of the functional configuration of a work vehicle. As shown in Fig. 9, the functional systems of the work vehicle 1 include a fuel system FS, a power system PS, and a temperature control system TS.

[0050] The components of the fuel system FS include at least one tank 13, valves 74 to 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 30.

[0051] 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 a fill port 26 to each tank 13. Hydrogen gas is introduced into fill port 26 from a hydrogen gas supply device 400 at a gas station or the like. Pipe 22A guides the hydrogen gas introduced into fill port 26 to each tank 13.

[0052] An on-off valve 74 is provided in the piping 22A. The on-off valve 74 switches between introducing hydrogen gas and stopping (shutting off) the introduction. The on-off valve 74 can open, for example, when it detects that hydrogen gas is being introduced into the filling port 26, and close when it detects that hydrogen gas is not being introduced. The introduction of hydrogen gas from the filling nozzle 401 to the filling port 26 can be detected, for example, by detecting the filling nozzle 401 connected to the filling port 26 with a contact sensor or a non-contact sensor. Alternatively, the detection can be performed by detecting a change in pressure at the filling port 26.

[0053] The pipe 22A branches into multiple parts downstream, and each branch portion 22A1 is connected to the tank 13. A check valve 75 is provided in each branch portion 22A1 of the pipe 22A. Each check valve 75 prevents backflow of hydrogen gas from each tank 13 toward the filling port 26.

[0054] 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 gas from each tank 13 and stopping (shutting off) the release.

[0055] 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. The on-off valves 74, 76, 78 are constituted by electromagnetic valves operated by solenoids, motor-operated valves operated by motors, or the like.

[0056] 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, a temperature sensor 82 is provided in the tank 13. The temperature sensor 82 detects the temperature of the hydrogen gas inside the tank 13.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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 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.

[0066] 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.

[0067] 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. 2). 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] As shown in FIG. 9 , the work vehicle 1 further includes a control device 70. The control device 70 may be configured, for example, with 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 includes an ECU that controls the overall operation of the system, from filling the tank 13 with hydrogen gas and generating electricity using the fuel cell 24 to outputting power, as well as ECUs involved in individual control of the tank unit 21, which includes the tank 13, valves 74-78, and sensors 81 and 82. Therefore, the control device 70 controls the opening and closing of the valves 74-78 included in the tank unit 21, acquires detection values ​​from the pressure sensor 81 and temperature sensor 82, and processes the acquired detection values.

[0072] The control device 70 executes, for example, a filling monitoring control for monitoring the state of hydrogen gas being filled from the hydrogen gas supply device 400 into the tank 13. Specifically, the control device 70 determines whether or not there is an abnormality in the state of hydrogen gas being filled. The details of the filling monitoring control will be described below.

[0073] [Filling Monitoring Control] The control device 70 acquires the detection value of the temperature sensor 82 for filling monitoring control. When the tank 13 is filled with hydrogen gas, the temperature inside the tank 13 rises. For example, the faster the hydrogen gas is filled from the hydrogen gas supply device 400 into the tank 13, the more rapidly the temperature inside the tank 13 rises. An allowable temperature for hydrogen gas is set in the tank 13. For example, the allowable temperature is set to 85°C. The tank 13 is designed to forcibly leak hydrogen gas if the temperature of the hydrogen gas inside rises above the allowable temperature.

[0074] The control device 70 monitors whether the temperature of the hydrogen gas in the tank 13 detected by the temperature sensor 82 exceeds a predetermined threshold value. The predetermined threshold value is a value equal to or lower than the allowable temperature of the tank 13. If the allowable temperature of the tank 13 is 85°C, the threshold value is set to 80°C, for example. The control device 70 obtains the detected value from the temperature sensor 82 and compares the detected value with the predetermined threshold value to determine whether or not there is an abnormality in the temperature of the hydrogen gas.

[0075] When the control device 70 determines that there is an abnormality in the temperature of the hydrogen gas, it controls and activates the alarm device 71. The alarm device 71 can issue information indicating an "abnormality." For example, if the alarm device 71 is a display device, it can display text information about the state of the hydrogen gas or the filling status, or information calling for attention, such as information indicating that an abnormality has occurred in the hydrogen gas filling, information indicating that the hydrogen gas temperature is rising, or information indicating that filling needs to be stopped. If the alarm device 71 is a speaker, it can output this information audibly. Furthermore, if the alarm device 71 is a lamp, it can issue an abnormality or a warning by lighting or flashing the lamp. The alarm device (display device) 71 can directly display the value detected by the temperature sensor 82. Based on the notification from the alarm device 71, the user can take action to eliminate the abnormality, such as stopping the hydrogen gas filling.

[0076] If the control device 70 determines that there is an abnormality in the temperature of the hydrogen gas, it can close the on-off valve 74 to stop the filling. This allows the tank 13 to continue being filled with hydrogen gas even if an abnormality has occurred, and prevents the temperature of the hydrogen gas from rising further. The control device 70 may use the alarm device 71 to notify that filling has been stopped.

[0077] 10 is a flowchart showing the control procedure for the filling monitoring control. The abnormality determination and notification procedure in the above filling monitoring control will be described with reference to the flowchart in FIG. 10. In step S1, the control device 70 determines whether hydrogen gas is being filled into the tank 13 from the hydrogen gas supply device 400. For example, it determines whether the filling nozzle 401 of the hydrogen gas supply device 400 is inserted into the filling port 26. If the control device 70 determines that hydrogen gas is being filled, in step S2, it acquires a detection value from the temperature sensor 82.

[0078] Next, in step S3, the control device 70 determines whether the detected value T exceeds a predetermined threshold value Tth. If the detected value T exceeds the threshold value Tth, the process proceeds to step S4. If the detected value T does not exceed the threshold value Tth, the process returns to step S1. In step S4, the control device 70 controls the alarm device 71 to alarm an abnormality. Next, the control device 70 closes the on-off valve 74 to stop the introduction of hydrogen gas from the filling port 26 into the tank 13.

[0079] [Example of arrangement of filling port and alarm device] In the above-described embodiment (see Figures 3 and 8), the filling unit 25 (filling port 26) and alarm device 71 were arranged at the rear (rear surface) of the work vehicle 1, but this is not limited to this. For example, the filling port 26 and alarm device 71 can be arranged on the side, top, or front of the work vehicle 1. In either case, the alarm device 71 is arranged near the filling port 26 so that it is easy for the person filling the filling port 26 with hydrogen gas (filler) to see. Here, "near the filling port 26" refers to, for example, a range within a radius of 1 m from the filling port 26. Alternatively, the alarm device 71 is arranged on a surface that is common to the surface of the work vehicle 1 on which the filling port 26 is arranged.

[0080] 2 to 6, examples of the layout of the filling port 26 and the alarm device 71 will be described. In FIGS. 2 to 6, the layout example of the filling port 26 is indicated by the symbol Q, and the layout example of the alarm device 71 is indicated by the symbol H.

[0081] 4 and 5, the filling port 26 can be provided on a side surface (Q1) of the hood 34, a side surface (Q2) of the cover 111, or a side surface (Q3, Q4) of the fender 47. The alarm device 71 can be disposed on a side surface (H1) of the hood 34, a side surface (H2) of the cover 111, a side surface (H3, H4) of the cabin 16, or a side surface (H5) of the tank unit 21.

[0082] With the above arrangement, both the filling port 26 and the alarm device 71 can be seen when the work vehicle 1 is viewed from the left or right side. When the alarm device 71 is arranged on the side surface (H5) of the tank unit 21, the alarm device 71 can be easily seen even from a distance because it is at a relatively high position.

[0083] 2, the filling port 26 can be disposed on the front surface (Q5) of the hood 34. Similarly, the alarm device 71 can be disposed on the front surface (H6) of the hood 34. The alarm device 71 can also be disposed on the front surface (H7) of the cabin 16, the front surface (H8) of the tank unit 21, or the like.

[0084] With the above arrangement, both the filling port 26 and the alarm device 71 can be seen when viewing the work vehicle 1 from the front. If the alarm device 71 is arranged on the front surface (H8) of the tank unit 21, it is at a relatively high position and therefore easy to see the alarm device 71 even from a distance.

[0085] 6, the fill port 26 can be arranged on the upper surface (Q6) of the hood 34, the upper surface (Q7) of the cover 111, the upper surface (Q8) of the fender 47, etc. The alarm device 71 can also be arranged on the upper surface (H9) of the hood 34, the upper surface (H10) of the cover 111, the upper surface (H11) of the fender 47, etc. By arranging them in the above manner, both the fill port 26 and the alarm device 71 can be seen when the work vehicle 1 is viewed from above.

[0086] 3, the filling port 26 can be disposed on the rear surface (Q8) of the fender 47. The alarm device 71 can be disposed on the rear surface (H11) of the fender 47, the rear surface (H12) of the cabin 16, the rear surface (H13) of the tank unit 21, etc. If the alarm device 71 is disposed on the rear surface (H13) of the tank unit 21, it is easy to see the alarm device 71 even from a distance because it is at a relatively high position.

[0087] In addition to the above, for example, by arranging one of the filling port 26 and the alarm device 71 on the rear surface of the work vehicle 1 and the other on a side surface of the work vehicle 1, it is possible to fit both the filling port 26 and the alarm device 71 within the field of view when the work vehicle 1 is viewed from the diagonal rear side. Alternatively, by arranging one of the filling port 26 and the alarm device 71 on the front surface of the work vehicle 1 and the other on a side surface of the work vehicle 1, it is possible to fit both the filling port 26 and the alarm device 71 within the field of view when the work vehicle 1 is viewed from the diagonal front side. Alternatively, by arranging one of the filling port 26 and the alarm device 71 on the top surface of the work vehicle 1 and the other on a side surface of the work vehicle 1, it is possible to fit both the filling port 26 and the alarm device 71 within the field of view when the work vehicle 1 is viewed from the diagonal top side.

[0088] When the notification device 71 is a display device, it can be disposed not only outside but also inside the cabin 16, with the display surface facing the outside of the cabin 16. In this case, the display content of the notification device 71 can be confirmed even from outside the cabin 16.

[0089] [Other Modifications] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is not limited to the above-described embodiments, and includes all modifications within the scope of equivalents to the configurations described in the claims.

[0090] When the control device 70 determines that there is an abnormality in the filling of hydrogen gas, it may not stop the filling of hydrogen gas (step S5 in FIG. 10) but may only issue a warning by the notification device 71 (step S4 in FIG. 10). In this case, the notification device 71 can continue to issue a warning until the filler stops the filling. Furthermore, when the filling of hydrogen gas is stopped, the notification device 71 can issue information indicating that the filling of hydrogen gas has been stopped.

[0091] The notification device 71 may be equipped with a control device (ECU). In this case, the notification device 71 acquires the detection value of the temperature sensor 82, determines whether or not there is an abnormality based on the detection value, and can notify information corresponding to the detection value, such as the determination result.

[0092] The notification device 71 may be disposed inside the driver's seat 15 or inside the cabin 16. In this case, the driver in the driver's seat 15 can easily check the notification content. If the notification device 71 is a display device, each of the hood, cover, cabin, etc. of the work vehicle 1, or the entirety of these, can be used as a display panel.

[0093] The alarm device 71 may issue information according to the detection value of the pressure sensor 81. In this case, the control device 70 acquires the detection value of the pressure sensor 81, determines whether or not there is a filling abnormality based on the detection value, and the alarm device 71 issues information according to the detection value such as the determination result.

[0094] Although the work vehicle 1 in the above embodiment is provided with a plurality of tanks 13, it may be provided with a single tank 13.

[0095] The work vehicle 1 may have a communication function for communicating with the hydrogen gas supply device 400 side.

[0096] 1: Work vehicle 13: Tank 15: Driver's seat 16: Cabin 70: Control device 71: Alarm device 82: Temperature sensor

Claims

1. A work vehicle comprising a fuel cell, a hydrogen tank for storing hydrogen supplied to the fuel cell, a sensor for detecting the state of hydrogen in the hydrogen tank, and a notification device for notifying information according to the detection value of the sensor.

2. The work vehicle according to claim 1, further comprising a filling port for filling hydrogen into the hydrogen tank, wherein the notification device is disposed in the vicinity of the filling port.

3. The work vehicle according to claim 1 or 2, further comprising a filling port for filling hydrogen into the hydrogen tank, wherein the notification device is a display device and is disposed within a range included in its field of view when the filling port is viewed from a predetermined direction.

4. The work vehicle according to any one of claims 1 to 3, further comprising a driver's seat, wherein the notification device is disposed outside the driver's seat.

5. The work vehicle according to claim 4, further comprising a cabin surrounding the driver's seat, wherein the notification device is disposed outside the cabin.

6. The work vehicle according to any one of claims 1 to 5, wherein the notification device notifies the presence or absence of filling abnormality obtained from the detection value.

7. The work vehicle according to claim 6, further comprising a control device for determining the presence or absence of filling abnormality based on the detection value of the sensor.

8. The work vehicle according to claim 7, wherein the control device determines that there is an abnormality when the detection value of the sensor exceeds a predetermined threshold value.

9. The work vehicle according to claim 7 or 8, wherein the control device stops the filling of hydrogen into the hydrogen tank based on the determination of the presence of an abnormality.

10. The work vehicle according to any one of claims 1 to 9, wherein the notification device notifies the detection value.

11. The work vehicle according to any one of claims 1 to 10, wherein the sensor is a temperature sensor.

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