Work vehicle

Abstract

This work vehicle includes: a body; a fuel cell mounted on the body; a tank for storing fuel that is supplied to the fuel cell; and a first loading port and a second loading port for loading fuel into the tank.

Description

Work vehicles

[0001] This disclosure relates to a fuel cell-powered work vehicle. This application claims priority to Japanese Patent Application No. 2023-219057, filed December 26, 2023, and incorporates by reference all of the contents of said Japanese application.

[0002] In order to protect the global environment, a work vehicle such as a tractor has been proposed that uses a fuel cell that generates electricity using hydrogen gas instead of an internal combustion engine that uses fossil fuels, and that the traveling device and work device are operated by an electric motor driven by the generated electricity (see Patent Document 1). This work vehicle is equipped with a tank that stores hydrogen gas. Patent Document 2 discloses a gas filling system that includes a vehicle equipped with a fuel cell and a tank, and a gas station. The gas station has a filling nozzle connected to a hydrogen gas supply source, and the vehicle has a filling port (receptacle) to which the filling nozzle is connected, and the filling port is connected to the tank via a pipe. The vehicle's tank is filled with hydrogen gas from the hydrogen gas supply source via the filling nozzle, the filling port, and the pipe.

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

[0004] The work vehicle of the present disclosure comprises a vehicle body, a fuel cell mounted on the vehicle body, a tank that stores fuel to be supplied to the fuel cell, and a first fill port and a second fill port for filling the tank with fuel.

[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 a filling port of a work vehicle. FIG. 9 is a block diagram showing an example of the functional configuration of a work vehicle. FIG. 10 is a schematic cross-sectional view showing an example of installation of a filling port. FIG. 11A is a schematic view showing a modified example of the connection between a tank and a filling port. FIG. 11B is a schematic view showing another modified example of the connection between a tank and a filling port. FIG. 11C is a schematic view showing another modified example of the connection between a tank and a filling port.

[0006] <Problem to be Solved by the Present Disclosure> There are very large work vehicles such as tractors, with an overall height of up to 3 m, for example. Therefore, when filling a tank with hydrogen gas from a filling port, it can be difficult to maneuver the work vehicle in order to bring the filling port close to the filling nozzle at the gas station, and the hydrogen gas filling operation can become complicated.

[0007] An object of the present disclosure is to provide a work vehicle that allows fuel filling operations to be easily performed.

[0008] Effect of the Present Disclosure According to the present disclosure, it is possible to provide a work vehicle that allows easy fuel filling operations.

[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 vehicle body, a fuel cell mounted on the vehicle body, a tank that stores fuel to be supplied to the fuel cell, and a first fill port and a second fill port for filling the tank with fuel.

[0010] According to the above configuration, since the work vehicle is equipped with the first and second filler ports, it is possible to selectively use either filler port by bringing it closer to the filler nozzle of the fuel supply device or to use both filler ports depending on the installation situation of the fuel supply device at the gas station or the structure of the work vehicle, making it possible to perform fuel filling operations according to the situation. This improves the convenience of the fuel filling operation and makes the filling operation easier. Note that the present disclosure does not prevent the work vehicle from being equipped with filler ports other than the first filler port and the second filler port. Therefore, the work vehicle may be equipped with three or more filler ports.

[0011] (2) In the work vehicle described in (1) above, the first filling port is disposed on one side surface of the vehicle body in the left-right direction, and the second filling port is disposed on the other side surface of the vehicle body in the left-right direction. This configuration reduces the amount of movement of the work vehicle, such as changes in direction, when bringing the filling port closer to the filling nozzle of the fuel supply device.

[0012] (3) In the work vehicle described in (1) above, the first filling port is disposed on one side surface of the vehicle body in the longitudinal direction, and the second filling port is disposed on the other side surface of the vehicle body in the longitudinal direction. With this configuration, it is possible to reduce the amount of movement of the work vehicle, such as changes in direction, when bringing the filling port closer to the filling nozzle of the fuel supply device.

[0013] (4) In the work vehicle described in (1) above, the first filling port is disposed on one side surface of the vehicle body in the left-right direction, and the second filling port is disposed on one side surface of the vehicle body in the front-rear direction. With this configuration, it is possible to reduce the amount of movement of the work vehicle, such as changes in direction, when bringing the filling port closer to the filling nozzle of the fuel supply device.

[0014] (5) In the work vehicle described in (1) above, the first filling port and the second filling port are arranged on a common surface of the vehicle body.

[0015] This configuration reduces the amount of movement of the work vehicle, such as back and forth, when bringing the filling port closer to the filling nozzle of the fuel supply machine. Also, it is easy to fill both filling ports with fuel at the same time.

[0016] (6) In the work vehicle described in any one of (1) to (5) above, the vehicle body includes a cover that covers the mounted equipment, and at least one of the first filling port and the second filling port is located inside or outside the cover.

[0017] (7) In the work vehicle described in any one of (1) to (6) above, the tank includes a first tank and a second tank, and the work vehicle is provided with piping that connects both the first filling port and the second filling port to the first tank and the second tank.

[0018] With this configuration, the first and second tanks can be filled with fuel through either the first or second fill port. Note that the present disclosure does not prevent the work vehicle from being equipped with tanks other than the first and second tanks. Therefore, the work vehicle may be equipped with three or more tanks.

[0019] (8) In the work vehicle described in (7) above, the piping includes a first branch portion having one end connected to the first filling port, a second branch portion having one end connected to the second filling port, and a junction portion where the other ends of the first branch portion and the second branch portion are joined together, and the first branch portion and the second branch portion are provided with check valves that allow fuel to flow in a direction toward the junction portion and block fuel flow in the opposite direction.

[0020] According to this configuration, it is possible to prevent fuel supplied from one filling port from flowing to the other filling port.

[0021] (9) In the work vehicle described in any one of (1) to (6) above, the tank includes a first tank and a second tank, and is equipped with a first pipe connecting the first filling port to the first tank and a second pipe connecting the second filling port to the second tank.

[0022] With this configuration, the first and second tanks can be filled with fuel separately from the first and second filling ports, and by filling fuel simultaneously from both filling ports, fuel can be filled in a short time.

[0023] <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. 2 to 7, the forward, backward, left, right, up, and down directions are indicated by arrows X1, X2, Y1, Y2, Z1, and Z2, respectively.

[0024] 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 body such as agricultural machinery, construction machinery, or a utility vehicle.

[0025] The work vehicle 1 includes a vehicle body 11, a traveling 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. 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. The hood 34, the cover 111, and the cabin 16 all function as covers that cover the equipment mounted on the vehicle body 11 (such as the fuel cell 24, radiators 48 and 49, and the seat 15A, which will be described later).

[0026] The work vehicle 1 further includes a tank unit 21 having multiple tanks 13 (see FIG. 4) 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 liquid or gas, and may be hydrogen, methane, carbon monoxide (CO), or the like. In this embodiment, the tank 13 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 a fuel cell 24 as an energy source. The fuel cell 24 generates electricity using hydrogen. The fuel cell 24 may also generate electricity using methane or carbon monoxide (CO).

[0028] The drive device 14 includes a fuel cell 24, a battery unit 30, and an electric motor 31 (see FIG. 3; 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] As shown in FIG. 3 , the work vehicle 1 has a pipe 22 and a filling unit 25. In this embodiment, the pipe 22 allows hydrogen gas to pass through. However, the pipe 22 may also be a pipe allowing methane or carbon monoxide (CO) to pass through. The filling unit 25 has a filling port (receptacle; hereinafter simply referred to as the "filling port") 26 to which a filling nozzle 401 is connected. The filling port 26 is filled with hydrogen gas through the filling nozzle 401. However, the filling port 26 may also be filled with methane or carbon monoxide (CO) through the filling nozzle 401. In this embodiment, the filling port (gas filling port) 26 of the filling unit 25 is filled with hydrogen gas from a hydrogen gas supply machine (fuel supply machine) 400 (see FIG. 9 ) such as a gas station that is separate from the work vehicle 1. The hydrogen gas is supplied to the tank 13 through the pipe 22 (22A). The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22 (22B). The specific configuration of the filling section 25 and the piping 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 sides 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 a hood (cover) 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 placed on and connected to the ceiling frame 17A. As shown in Figure 2, the ceiling frame 17A is located higher than the roof of the cabin 16. Therefore, the tank unit 21 is disposed above the roof of the cabin 16.

[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] FIG. 8 is a perspective view showing the area around the filling port of the work vehicle. The work vehicle 1 of this embodiment is equipped with two filling units 25. The two filling units 25 are arranged on the rear surface of the work vehicle 1 (vehicle body 11). Each filling unit 25 has a filling port 26 and a housing 28 that houses the filling port 26. The filling port 26 faces rearward, and a filling nozzle 401 of a hydrogen gas supply device 400 is inserted from the rear. 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 is open at the rear. The lid 28b is openable and can close the opening of the case 28a. 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] The two filling sections 25 are located behind the cabin 16 and between the rear wheels 12B on both the left and right sides. The two filling sections 25 are protected from the left and right by the rear wheels 12B and from the front by the cabin 16.

[0045] The two filling sections 25 are disposed below the base frame 17D of the mounting frame 17. Both filling sections 25 are supported on the base frame 17D via brackets 27. The filling sections 25 are protected from above by the base frame 17D. The two filling sections 25 are disposed between the left and right lower frames 17E.

[0046] One filling unit 25 and the other filling unit 25 are arranged side by side. One filling unit 25 is arranged to the left of the center in the left-right direction of the work vehicle, and the other filling unit 25 is arranged to the right of the center in the left-right direction of the work vehicle. Therefore, when the filling nozzle 401 of the hydrogen gas supply device 400 is on the left side of the work vehicle 1, it is easier to fill hydrogen gas using the filling unit 25 on the left, and when the filling nozzle 401 of the hydrogen gas supply device 400 is on the right side of the work vehicle 1, it is easier to fill hydrogen gas using the filling unit 25 on the right.

[0047] The two filling sections 25 are arranged at the same height. However, the two filling sections 25 may be arranged at different heights. The two filling sections 25 may be arranged next to each other in the vertical direction. By having the two filling sections 25 at different heights, it is possible to select the filling section 25 that is easiest for the worker to work in, depending on the worker's height, posture, etc., and fill the hydrogen gas therein.

[0048] [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.

[0049] The components of the fuel system FS include at least one tank (hydrogen 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.

[0050] 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.

[0051] The pipe 22A has a plurality of downstream branch portions 22A1, a confluence portion 22A2, and a plurality of upstream branch portions 22A3. The number of upstream branch portions 22A3 is the same as the number of filling ports 26 (two in the illustrated example). One end (upstream end) of each upstream branch portion 22A3 is connected to one of the filling ports 26. One end (upstream end) of the confluence portion 22A2 is connected to the other end (downstream end) of each of the two upstream branch portions 22A3.

[0052] The other end (downstream end) of the confluence 22A2 is connected to one end (upstream end) of each of the plurality of downstream branch sections 22A1. The number of downstream branch sections 22A1 is the same as the number of tanks 13 (three in the illustrated example). The other end (downstream end) of each downstream branch section 22A1 is connected to each of the tanks 13. Therefore, the hydrogen gas introduced from the filling port 26 flows through each of the upstream branch sections 22A3, is joined at the confluence 22A2, is then branched at each of the downstream branch sections 22A1, and is filled into each of the tanks 13.

[0053] The upstream branch section 22A3 is provided with a check valve 74. The check valve 74 allows hydrogen gas to flow from the filling port 26 toward the junction section 22A2 and blocks hydrogen gas from flowing in the opposite direction. This prevents hydrogen gas introduced from one filling port 26 from flowing into the other filling port 26.

[0054] The downstream branch section 22A1 is also provided with a check valve 75. The check valve 75 allows hydrogen gas to flow from the confluence section 22A2 toward the tank 13 and blocks hydrogen gas from flowing in the opposite direction. This prevents hydrogen gas in the tank 13 from flowing back into the downstream branch section 22A1.

[0055] As described above, the work vehicle 1 of this embodiment can fill all of the tanks 13 with hydrogen gas regardless of which of the two filling ports 26 hydrogen gas is supplied from. Also, even if hydrogen gas is supplied from both filling ports 26 simultaneously, hydrogen gas can be filled into all of the tanks 13.

[0056] 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 has a branch portion 22B1 and a junction portion 22B2. The number of branch portions 22B1 is the same as the number of tanks 13 (three in the illustrated example). One end (upstream end) of the branch portion 22B1 is connected to the tank 13, and the other end (downstream end) is connected to the junction portion 22B2. Therefore, the hydrogen gas released from each tank 13 flows through the branch portion 22B1, is joined at the junction portion 22B2, and then is guided to the fuel cell 24.

[0057] An on-off valve 76 is provided at each branch 22B1 of the pipe 22B. Each on-off valve 76 switches between releasing and stopping (shutting off) the hydrogen gas release from each tank 13. 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 in the tank 13 is, for example, 35 megapascals or more, while 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 76, 78 are configured as electromagnetic valves operated by solenoids, motor-operated valves, etc.

[0058] 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 each tank 13. The temperature sensor 82 detects the temperature of the hydrogen gas inside the tank 13.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 76-78 included in the tank unit 21, acquires detection values ​​from the pressure sensor 81 and temperature sensor 82, and processes the acquired detection values.

[0074] [Example of Filling Port Arrangement] In the above-described embodiment (see Figures 3 and 8), the two filling ports 26 (filling section 25) were arranged at the rear (rear surface) of the work vehicle 1. However, this is not limited to this. For example, the two filling ports 26 can be arranged on the side, top, and / or front surface of the work vehicle 1. The two filling ports 26 can be arranged in positions close to each other, or can be arranged in positions far from each other. The two filling ports 26 are not limited to being arranged on a common surface of the work vehicle 1, but can also be arranged on different surfaces.

[0075] Examples of the layout of the filling port 26 will be described below with reference to Figures 2 to 6. In Figures 2 to 6, the layout examples of the filling port 26 are indicated by the symbol Q.

[0076] As shown in Figures 4 and 5, the two filler ports 26 can be arranged on both left and right side surfaces of the hood 34, indicated by the symbol Q1. In this case, as illustrated in Figure 10, the filler port 26 may be arranged on the inside of the hood 34. Specifically, a portion of the side surface of the hood 34 can serve as a lid 28b for the housing 28, with the case 28a for the housing 28 arranged inside the lid 28b, and the filler port 26 can be arranged inside the housing 28. The filler port 26 is arranged so as to face outward in the left and right direction. The filler port 26 and the housing 28 can also be arranged on the outside of the hood 34.

[0077] As shown in Figures 4 and 5, the two filling ports 26 may be located on both left and right side surfaces of the cover 111, indicated by reference symbol Q2. Alternatively, the filling ports 26 may be located on both left and right side surfaces of the fender 47, indicated by reference symbols Q3 and Q4. Reference symbol Q3 indicates an example in which the filling port 26 is located closer to the front of the fender 47, and reference symbol Q4 indicates an example in which the filling port 26 is located closer to the rear of the fender 47. In either case (Q2 to Q4), the filling port 26 may be located on the inside or outside of the cover 111 or fender 47.

[0078] 4 and 5, the two filling ports 26 may be located on both the left and right side surfaces of the cabin 16, indicated by reference symbols Q5 and Q6. Reference symbol Q5 indicates an example in which the filling port 26 is located closer to the front of the cabin 16, and reference symbol Q6 indicates an example in which the filling port 26 is located closer to the rear of the cabin 16. In either case, the filling port 26 may be located inside or outside the cabin 16.

[0079] As described above, by distributing the two filling ports 26 to the left and right sides of the work vehicle 1 (vehicle body 11), it is possible to reduce the amount of movement, such as turning of the work vehicle 1, when, for example, bringing the filling port 26 close to a hydrogen gas supply device 400 at a gas station or the like. This reduces the effort required for the filling operation, making the filling operation easier.

[0080] In FIGS. 4 and 5 , the two filling ports 26 can be positioned at any two of Q1 to Q6. For example, one of the two filling ports 26 can be positioned on the hood (Q1), and the other can be positioned on the fenders 47 (Q3, Q4). Furthermore, both of the two filling ports 26 can be positioned on the left or right side of the work vehicle 1 (body 11). In this case, the two filling ports 26 can be positioned at positions spaced apart from each other in the longitudinal direction and / or in the vertical direction. For example, one of the two filling ports 26 can be positioned on the left side of the hood 34 (Q1), and the other can be positioned on the left side of the fenders 47 (Q3, Q4). By positioning the two filling ports 26 on a common surface of the work vehicle 1, it is possible to easily fill the work vehicle 1 with hydrogen gas simultaneously through both filling ports 26. Furthermore, when the two filling ports 26 are positioned at positions spaced apart from each other in the longitudinal direction, the amount of longitudinal movement of the work vehicle 1 can be reduced when bringing the filling ports 26 closer to a hydrogen gas supply device 400, such as a gas station. This reduces the time and effort required for the filling operation and makes the filling operation easier.

[0081] As shown in FIG. 2 , one or both of the two filling ports 26 can be located on the front of the work vehicle 1 (vehicle body 11). For example, the filling port 26 can be located on the front of the hood 34, indicated by the symbol Q7. In this case, the filling port 26 can also be located on the inside or outside of the hood 34. When the two filling ports 26 are located on the front of the work vehicle 1, the two filling ports 26 can be located at positions spaced apart from each other in the vertical direction and / or in the horizontal direction. When one filling port 26 is located on the front of the work vehicle 1, the other filling port 26 can be located at another position on the work vehicle 1 (for example, on the rear (see FIG. 8 ), on the left and right side surfaces Q1 to Q6 (see FIGS. 4 and 5 ), or on the top surface Q8 to Q10 (see FIG. 6 )).

[0082] As shown in FIG. 6 , one or both of the two filling ports 26 can be disposed on the top surface of the work vehicle 1 (vehicle body 11). Specifically, the filling ports 26 can be disposed on the top surface of the hood 34 indicated by reference symbol Q8, the top surface of the cover 111 indicated by reference symbol Q9, the top surface of the fender 47 indicated by reference symbol Q10, or the like. When the two filling ports 26 are disposed on the top surface of the work vehicle 1, the two filling ports 26 can be disposed at positions spaced apart from each other in the front-to-rear direction and / or positions spaced apart from each other in the left-to-right direction. When one filling port 26 is disposed on the top surface (Q9, Q10) of the work vehicle 1, the other filling port 26 can be disposed at another position on the work vehicle 1 (for example, the front surface Q7 (see FIG. 2 ), the rear surface (see FIG. 8 ), or the left and right side surfaces Q1 to Q6 (see FIGS. 4 and 5 )).

[0083] As shown in Figure 3, one or both of the two filling ports 26 can be located on the rear surface of the fender 47, designated by reference symbol Q10, or on the rear surface of the cabin 16, designated by reference symbol Q11. When one filling port 26 is located on the rear surface of the work vehicle 1 (Q10, Q11, see Figure 3), the other filling port 26 can be located in another position on the work vehicle 1 (for example, on the front surface (see Figure 2), on the left and right side surfaces Q1 to Q6 (see Figures 4 and 5), or on the top surface Q8 to Q10 (see Figure 6)).

[0084] In addition to the above, the filler ports 26 may be disposed on the chassis 41 of the body 11 of the work vehicle 1. For example, one or both of the filler ports 26 may be disposed on the left and right side surfaces of the front frame 32 or the left and right side surfaces of the transmission case 33. Alternatively, one or both of the filler ports 26 may be disposed on the underside of the chassis 41.

[0085] 11A to 11C are schematic diagrams showing modified examples of the connection between the tank and the filling port. In other words, Fig. 11A to Fig. 11C show modified examples of the piping 22A that connects the tank 13 and multiple filling ports 26.

[0086] 11A has two tanks 13 and two filling inlets 26. One tank 13 and one filling inlet 26 are directly connected by a pipe 22A4, and the other tank 13 and the other filling inlet 26 are directly connected by another pipe 22A4. Each pipe 22A4 is provided with a check valve 74. Therefore, hydrogen gas supplied from one filling inlet 26 fills only one tank 13, and hydrogen gas supplied from the other filling inlet 26 fills only the other tank 13. In this modification, for example, hydrogen gas can be supplied from both filling inlets 26 simultaneously, thereby filling the tanks 13 with hydrogen gas in a short time.

[0087] In the modified example shown in FIG. 11B , similar to the modified example shown in FIG. 11A , two filling ports 26 and two tanks 13 are individually connected by pipes 22A4. Furthermore, the two pipes 22A4 are connected by a connecting pipe 22A5. An on-off valve 79 is provided on the connecting pipe 22A5. The on-off valve 79 opens and closes to switch between allowing and blocking the flow of hydrogen gas through the connecting pipe 22A5. In this modified example, similar to the modified example shown in FIG. 11A , by closing the on-off valve 79, hydrogen gas supplied from one filling port 26 fills only one tank 13, and hydrogen gas supplied from the other filling port 26 fills only the other tank 13. Furthermore, by opening the on-off valve 79, the two pipes 22A4 are connected to each other, and hydrogen gas supplied from each filling port 26 fills both tanks 13. Therefore, hydrogen gas can be filled in two ways by opening and closing the on-off valve 79.

[0088] 11C , similar to the embodiment shown in FIG. 9 , two (the upper two) tanks 13 and two (the upper two) filling ports 26 are connected by a pipe 22A having a downstream branch portion 22A1, a confluence portion 22A2, and an upstream branch portion 22A3. Furthermore, one (the lowest) tank and one (the lowest) filling port 26 are connected by a pipe 22A4. Similar to the modification shown in FIG. 11B , the confluence portion 22A2 and the pipe 22A4 are connected by a connecting pipe 22A5 provided with an on-off valve 79. In this modification, by closing the on-off valve 79, hydrogen gas supplied from the two upper filling ports 26 is supplied to the two upper tanks 13, and hydrogen gas supplied from the lowest filling port 26 is supplied only to the lowest tank 13. Furthermore, by opening the on-off valve 79, the hydrogen gas supplied from each filling port 26 is filled into the three tanks 13. Therefore, by opening and closing the on-off valve 79, hydrogen gas can be filled in two ways.

[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] In the above embodiment, the work vehicle 1 has mainly been described as having two fill ports 26, but it may also have three or more fill ports 26. In this case, two fill ports (first fill port and second fill port) 26 can be disposed at the positions shown in Figures 2 to 6 and 8, and the other fill ports 26 can be disposed at any position. Furthermore, the number of tanks 13 is not limited.

[0091] 1: Work vehicle 11: Vehicle body 13: Tank 22A: Pipe 22A2: Junction 22A3: Upstream branch 24: Fuel cell 74: Check valve 111: Cover

Claims

1. A work vehicle comprising a vehicle body, a fuel cell mounted on the vehicle body, a tank for storing fuel supplied to the fuel cell, and a first filling port and a second filling port for filling the tank with fuel.

2. The work vehicle according to claim 1, wherein the first filling port is disposed on one side surface of the vehicle body in the left-right direction, and the second filling port is disposed on the other side surface of the vehicle body in the left-right direction.

3. The work vehicle according to claim 1, wherein the first filling port is disposed on one side surface of the vehicle body in the front-rear direction, and the second filling port is disposed on the other side surface of the vehicle body in the front-rear direction.

4. The work vehicle according to claim 1, wherein the first filling port is disposed on one side surface of the vehicle body in the left-right direction, and the second filling port is disposed on one side surface of the vehicle body in the front-rear direction.

5. The work vehicle according to claim 1, wherein the first filling port and the second filling port are disposed on a common surface of the vehicle body.

6. The work vehicle according to any one of claims 1 to 5, wherein the vehicle body includes a cover for covering the mounted equipment, and at least one of the first filling port and the second filling port is disposed inside or outside the cover.

7. The work vehicle according to any one of claims 1 to 6, wherein the tank includes a first tank and a second tank, and a pipe connecting both the first filling port and the second filling port to the first tank and the second tank is provided.

8. The work vehicle according to claim 7, wherein the pipe includes a first branch portion having one end connected to the first filling port, a second branch portion having one end connected to the second filling port, and a confluence portion for joining the other ends of the first branch portion and the second branch portion, and the first branch portion and the second branch portion are provided with check valves for allowing the flow of fuel in the direction toward the confluence portion and blocking the flow of fuel in the reverse direction.

9. The work vehicle according to any one of claims 1 to 6, wherein the tank includes a first tank and a second tank, and a first pipe connecting the first filling port to the first tank and a second pipe connecting the second filling port to the second tank are provided.

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