Work vehicle

Abstract

The present disclosure relates to a work vehicle. The work vehicle according to the present disclosure comprises: a vehicle body; a driver's seat, an electric motor, and a fuel cell module that are mounted on the vehicle body; a cabin that is disposed around the driver's seat; a hydrogen pipe and a hydrogen tank that supply hydrogen to the fuel cell module; and a tank case that is disposed above the cabin and houses the hydrogen tank. The tank case includes a lower plate that covers the hydrogen tank from below, side plates that cover the hydrogen tank from the side, and an upper plate that covers the hydrogen tank from above, and the tank case has a first vent that opens in the lower plate.

Description

Work vehicles

[0001] The present disclosure relates to work vehicles.

[0002] Conventionally, a work vehicle equipped with an electric motor and a battery has been known (see Patent Document 1). The work vehicle disclosed in Patent Document 1 has the battery located inside the hood. The work vehicle disclosed in Patent Document 1 is a tractor.

[0003] Japanese Patent Application Laid-Open No. 2022-060655

[0004] The work vehicle of the present disclosure comprises a vehicle body, a driver's seat, an electric motor and a fuel cell module mounted on the vehicle body, a cabin arranged around the driver's seat, hydrogen piping and a hydrogen tank that supply hydrogen to the fuel cell module, and a tank case arranged above the cabin and that houses the hydrogen tank, the tank case including a lower plate that covers the hydrogen tank from below, side plates that cover it from the sides, and an upper plate that covers it from above, and having a first air vent opening in the lower plate.

[0005] The work vehicle of the present disclosure comprises a vehicle body, a driver's seat, an electric motor and a fuel cell module mounted on the vehicle body, a cabin arranged around the driver's seat, hydrogen piping and a hydrogen tank that supply hydrogen to the fuel cell module, and a tank case arranged above the cabin and that houses the hydrogen tank, the tank case including a lower plate that covers the hydrogen tank from below, side plates that cover it from the sides, and an upper plate that covers it from above, and has an opening and closing door that is supported on the side plates via hinges so that it can be opened and closed.

[0006] The present disclosure enables a work vehicle equipped with a fuel cell module to adequately protect a hydrogen tank with a tank case.The present disclosure enables a work vehicle equipped with a tank case for a hydrogen tank to easily maintain the hydrogen tank.

[0007] FIG. 1 is a perspective view showing an embodiment of a work vehicle according to the present disclosure. FIG. 2 is a front view showing an embodiment of a work vehicle according to the present disclosure. FIG. 3 is a rear view showing an embodiment of a work vehicle according to the present disclosure. FIG. 4 is a right side view showing an embodiment of a work vehicle according to the present disclosure. FIG. 5 is a left side view showing an embodiment of a work vehicle according to the present disclosure. FIG. 6 is a plan view showing an embodiment of a work vehicle according to the present disclosure. FIG. 7 is a bottom view showing an embodiment of a work vehicle according to the present disclosure. FIG. 8 is a perspective view showing a part of a work vehicle according to the present disclosure in an exploded state. FIG. 9 is a left side view of the work vehicle with a part removed. FIG. 10 is a perspective view of a tank case. FIG. 11 is an explanatory diagram of the installation status of the tank case in the work vehicle. FIG. 12 is a cross-sectional schematic view of a tank and a tank case. FIG. 13 is a perspective view showing the tank case and the tank inside with the opening and closing door open.

[0008] <Problem to be Solved by the Invention> In recent years, work vehicles that use a fuel cell module that generates electricity using hydrogen as fuel and drive an electric motor with the electricity have been considered. Such work vehicles are equipped with a hydrogen tank that stores hydrogen. There has been a demand for the development of a tank case that can adequately protect such a hydrogen tank from external impacts, temperature increases, etc. Such a tank case is also required to enable easy maintenance of the hydrogen tank housed inside.

[0009] The present disclosure aims to provide a tank case that adequately protects a hydrogen tank in a work vehicle equipped with a fuel cell module, and to facilitate maintenance of the hydrogen tank in a work vehicle equipped with a tank case for the hydrogen tank.

[0010] According to the present disclosure, in a work vehicle equipped with a fuel cell module, the hydrogen tank can be appropriately protected by the tank case. According to the present disclosure, in a work vehicle equipped with a tank case for the hydrogen tank, maintenance of the hydrogen tank can be facilitated.

[0011] <Outline of Embodiments of the Present Disclosure> An outline of embodiments of the present disclosure will be described below. (1) A work vehicle of this embodiment includes a vehicle body, a driver's seat, an electric motor, and a fuel cell module mounted on the vehicle body, a cabin arranged around the driver's seat, a hydrogen pipe and a hydrogen tank that supply hydrogen to the fuel cell module, and a tank case arranged above the cabin and that houses the hydrogen tank, the tank case including a lower plate that covers the hydrogen tank from below, side plates that cover the hydrogen tank from the sides, and an upper plate that covers the hydrogen tank from above, and having a first air vent opening in the lower plate.

[0012] According to the work vehicle according to the embodiment (1) above, the hydrogen tank can be adequately protected from external impacts, temperature rises, etc. As a result, in a work vehicle equipped with a fuel cell module, the hydrogen tank can be adequately protected by the tank case.

[0013] (2) In the work vehicle according to the embodiment (1), it is preferable that the tank case further has a second ventilation port that opens at the upper part of the side panel. A work vehicle having such a configuration can reliably suppress temperature increases inside the tank case. This allows the hydrogen tank to be adequately protected. The hydrogen tank can be adequately protected while ensuring ease of maintenance of the hydrogen tank.

[0014] (3) The work vehicle according to the embodiment (2) above preferably further includes a hydrogen sensor, which is disposed adjacent to the second vent inside the tank case. In a work vehicle configured in this manner, the hydrogen sensor can reliably detect hydrogen leaks occurring inside the tank case. This allows the hydrogen tank to be adequately protected.

[0015] (4) In the work vehicle according to the above embodiment (2) or (3), it is preferable that the upper plate is disposed at an incline relative to the lower plate, and the second vent is opened in the upper part of the side plate adjacent to the position of the upper plate farthest from the lower plate. With a work vehicle configured in this way, hydrogen leaked from the tank case can be reliably released to the outside of the tank case, thereby providing adequate protection for the hydrogen tank.

[0016] (5) In the work vehicle according to any one of the above embodiments (2) to (4), it is preferable that the tank case has the second vent in each of the two opposing side panels. With a work vehicle configured in this way, air that enters the tank case through the first vent is exhausted through the second vent by natural convection, allowing natural ventilation inside the tank case. Furthermore, hydrogen that leaks inside the tank case can be reliably exhausted to the outside of the tank case. This effectively protects the hydrogen tank.

[0017] (6) In the work vehicle of the present disclosure, it is preferable that the tank case has an opening / closing door that is supported on the side plate via a hinge so as to be openable and closable.

[0018] According to the work vehicle according to the embodiment (6) above, maintenance of the hydrogen tank can be easily performed in a work vehicle equipped with a tank case that houses the hydrogen tank.

[0019] (7) In the work vehicle of the embodiment (6) described above, it is preferable that the hydrogen tank has a valve that adjusts the amount of hydrogen that flows in and out, and that the opening and closing door is provided on the first side plate that faces the valve. With a work vehicle configured in this way, the first side plate of the tank case can be easily opened and closed. This allows for easy maintenance of the valve located directly behind the first side plate. This allows for accurate protection of the hydrogen tank while ensuring ease of maintenance of the hydrogen tank.

[0020] (8) In the work vehicle of the embodiment (7), it is preferable that the tank case has a second side plate parallel to the first side plate, and the opening / closing door is further provided on the second side plate. A work vehicle with such a configuration allows for easy maintenance of the entire hydrogen tank.

[0021] (9) In the work vehicle according to any one of the above embodiments (6) to (8), it is preferable that the upper plate of the tank case is inclined relative to the lower plate. With a work vehicle having such a configuration, rainwater that has fallen on the upper plate of the tank case can be quickly drained below the tank case.

[0022] (10) In the work vehicle of the embodiment (9), the tank case preferably has a third side plate and a fourth side plate perpendicular to the first side plate and the second side plate, and the top plate preferably slopes downward toward at least one of the third side plate and the fourth side plate. A work vehicle configured in this manner can drain rainwater that has fallen on the top plate of the tank case in a direction away from the door, thereby ensuring ease of maintenance of the hydrogen tank. Furthermore, a work vehicle configured in this manner can prevent rainwater from entering the tank case.

[0023] <Details of the embodiments of the present disclosure> Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0024] [Overall Configuration of Work Vehicle] Fig. 1 is a perspective view showing one embodiment of a work vehicle according to the present disclosure. Figs. 2 to 7 are a front view, a rear view, a side view (left side view), a side view (right side view), a plan view, and a bottom view of the work vehicle shown in Fig. 1. The work vehicle 10 of this embodiment is a vehicle that can be used for agricultural work, and the work vehicle 10 shown in Fig. 1 is a tractor. The work vehicle is not limited to a tractor. For example, the work vehicle according to the present invention may be an agricultural machine, a construction machine, a utility vehicle, or the like other than a tractor.

[0025] The directions of the work vehicle 10 of the present disclosure are defined below. The direction in which the work vehicle 10 moves forward is defined as "front," the direction in which the work vehicle 10 moves backward is defined as "rear," the left side when facing forward is defined as "left," and the right side when facing forward is defined as "right." The left-right direction perpendicular to the fore-aft direction is defined as the vehicle width direction. The direction perpendicular to both the fore-aft direction and the vehicle width direction (left-right direction) is defined as the up-down direction. The up-down direction is also called the height direction. In each figure, an orthogonal three-dimensional coordinate system is shown, with the forward direction indicated by arrow X1 and the backward direction indicated by arrow X2. The left direction is indicated by arrow Y1 and the right direction is indicated by arrow Y2. The up direction is indicated by arrow Z1 and the down direction is indicated by arrow Z2.

[0026] 1 includes a vehicle body 11, a traveling device 12 that supports the vehicle body 11 so that it can travel, a driver's seat 15, a cabin 16, a tank unit 21 having a tank 13 that stores fuel, and a drive device 14 that is powered by the fuel stored in the tank 13. The fuel is hydrogen, and the tank 13 is a hydrogen tank that stores hydrogen gas. The work vehicle 10 of this embodiment is a fuel cell vehicle (FCV) that travels using electricity generated by a fuel cell (fuel cell module) 24 using hydrogen and oxygen.

[0027] The work vehicle 10 has a drive device 14 that includes a fuel cell 24, a battery unit 30, and an electric motor 31. The battery unit 30 has a battery 300 that stores power generated by the fuel cell 24 and supplies the stored power to the motor 31. The work vehicle 10 has a hydrogen gas piping (hydrogen piping) 22 and a filling unit 25 (see FIG. 3 ). The filling unit 25 has a filling port (receptacle) 26 that connects to a filling nozzle of a hydrogen gas supply device (not shown) that is separate from the work vehicle 10. Hydrogen gas is supplied from the filling port 26 and supplied to the tank 13 through the piping 22 (rear piping 22r). The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the piping 22 (front piping 22f). The specific configurations of the filling unit 25 and the piping 22 will be described later.

[0028] The work vehicle 10 (see FIG. 1) has a mounting frame 17 and a support structure 37. The mounting frame 17 is a frame for mounting the tank unit 21 (tank 13) on the vehicle body 11. The support structure 37 is a component for supporting the battery unit 30 on the vehicle body 11. The work vehicle 10 (see FIG. 7) has an exhaust path 35. The exhaust path 35 exhausts water or water vapor generated by operation of the fuel cell 24 to the outside. The specific configurations of the mounting frame 17, the support structure 37, and the exhaust path 35 will be described later.

[0029] [Vehicle Body 11] The vehicle body 11 has a chassis 41, a hood 34, a cover 111, and a fender 47 that covers the rear wheels 122 from above. The chassis 41 supports the traveling device 12, the drive device 14, and the cabin 16. Figure 8 is an exploded perspective view of a portion of the work vehicle 10 shown in Figure 1. The chassis 41 is located in the center in the vehicle width direction and has a shape that is long in the vehicle front-to-rear direction. The chassis 41 has a front frame 32 that forms the front portion of the chassis 41, and a gear case 33 that forms the rear portion of the chassis 41. The front frame 32 is formed by combining metal frame materials and the like. The gear case 33 has a metal box body. The gear case 33 is connected to the rear portion of the front frame 32, and the gear case 33 and the front frame 32 form the framework of the vehicle body 11.

[0030] The front frame 32 carries the motor 31. The gear case 33 has therein a power transmission mechanism 333 such as a transmission, a clutch, a differential gear, etc. The power transmission mechanism 333 reduces or increases the rotation speed of the output shaft of the motor 31 and outputs the rotation to the traveling device 12 (one or both of the front wheels 121 and the rear wheels 122).

[0031] The power transmission mechanism 333 outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIG. 3 ). The PTO shaft 334 is an output shaft provided at the rear of the gear case 33. The work vehicle 10 has a coupling device 43 for coupling another device to the rear of the vehicle body 11. The PTO shaft 334 transmits the power of the motor 31 to the other device coupled to the coupling device 43. The other device is a work device (not shown), also called an implement. The work device is operated by the power of the motor 31. The work device is, for example, a tiller.

[0032] Figure 9 is a left side view of the work vehicle 10, showing the hood 34, cover 111, and a portion of the tank case 211 of the tank unit 21 removed. Starting from the front of the vehicle, the first radiator 48, fuel cell 24, and second radiator 49 are mounted on the chassis 41 in this order. As shown in Figures 4 and 9, the hood 34 and cover 111 cover the mounted components located near the front of the vehicle body 11. The hood 34 covers the fuel cell 24 and first radiator 48 from above and on both sides in the vehicle width direction. The cover 111 covers the second radiator 49 located behind the fuel cell 24 from above and on both sides in the vehicle width direction.

[0033] The upper surface 48a of the first radiator 48 is lower than the upper surface 24a of the fuel cell 24. The upper surface 24a of the fuel cell 24 is lower than the upper surface 49a of the second radiator 49. The upper surface 111a of the cover 111 is higher than the upper surface 34a of the hood 34, but lower than the upper end of the steering wheel 151 that is operated by an operator sitting in the driver's seat 15 to steer the vehicle. The upper surface 34a of the hood 34 becomes lower toward the front. This makes it less likely that the field of vision of the operator sitting in the driver's seat 15 will be obstructed.

[0034] [Driver's Seat 15 and Cabin 16] The driver's seat 15 and the cabin 16 are provided on the chassis 41 at a rearward position (see FIG. 1). The cabin 16 has the driver's seat 15 inside. The cabin 16 has front pillars 162 located in front of the driver's seat 15, rear pillars 163 located behind the driver's seat 15, and a roof 164 located above the driver's seat 15. The front pillars 162 are provided on the left front and right front of the driver's seat 15. The rear pillars 163 are provided on the left rear and right rear of the driver's seat 15. The roof 164 is supported by the front pillars 162 and rear pillars 163.

[0035] The cabin 16 has a windshield 165 located in front of the driver's seat 15. The windshield 165 is provided between the left and right front pillars 162. The cabin 16 has openable and closable doors 166 on both sides in the vehicle width direction. The doors 166 are provided between the front pillars 162 and the rear pillars 163.

[0036] A step 167 is provided on one side (left side) of the cabin 16 in the vehicle width direction (see FIG. 5). The step 167 is a member on which an operator places their feet when getting in and out of the cabin 16. A cover 111 and a bonnet 34 are provided in front of the cabin 16. As shown in FIGS. 2 and 6, the dimensions of the cover 111 and the bonnet 34 in the vehicle width direction are each smaller than the dimension of the cabin 16 in the vehicle width direction. The dimension of the bonnet 34 in the vehicle width direction is smaller than the dimension of the cover 111 in the vehicle width direction.

[0037] The work vehicle 10 of this embodiment has a cabin 16, but it does not have to have the cabin 16. The work vehicle 10 may have a canopy or ropes instead of the cabin 16. If the work vehicle 10 does not have a cabin 16, the tank unit 21 is supported by the mounting frame 17 and is located above the driver's seat 15.

[0038] [Traveling device 12] The traveling device 12 has front wheels 121 and rear wheels 122 (see FIG. 6). The front wheels 121 are provided on the left and right sides of the front part of the vehicle body 11. The rear wheels 122 are provided on the left and right sides of the rear part of the vehicle body 11. The maximum dimension in the vehicle width direction of the left and right rear wheels 122 is greater than the maximum dimension in the vehicle width direction of the left and right front wheels 121. The maximum dimension in the vehicle width direction of the left and right rear wheels 122 is the maximum vehicle width dimension of the work vehicle 10. One or both of the front wheels 121 and the rear wheels 122 rotate by the power of the motor 31. One or both of the front wheels 121 and the rear wheels 122 (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers).

[0039] [Drive unit 14] As described above, the drive unit 14 is configured to include the fuel cell 24, the battery unit 30, and the motor 31. The fuel cell 24 is located on the chassis 41 near the front of the vehicle body 11 (see FIG. 9). The motor 31 is located behind the fuel cell 24 (see FIG. 8). The battery unit 30 is located near the outer side of the vehicle body 11 in the vehicle width direction (see FIG. 1). The battery unit 30 is attached to the chassis 41 by a support structure 37.

[0040] The fuel cell 24 generates electricity using hydrogen gas to obtain the power to rotate the motor 31. The fuel cell 24 (see FIG. 9 ) has a battery casing 241 in the shape of a substantially rectangular box and a fuel cell stack 242 provided inside the battery casing 241. The fuel cell stack 242 has a plurality of battery cells. Each battery cell has a positive electrode and a negative electrode. A plurality of unit cells are stacked. The power generated by each battery cell is collected and output to the battery unit 30.

[0041] The motor 31 has a rotating rotor and a stator having a plurality of coils. The output shaft of the motor 31 is connected to a power transmission mechanism 333 in a gear case 33 (see FIG. 8). The motor 31 is located behind the fuel cell 24 and below the second radiator 49.

[0042] [Tank Unit 21] The tank unit 21 (see FIG. 9 ) has a tank 13 and a tank case 211 that houses the tank 13. The tank 13 is a substantially cylindrical high-pressure vessel. The tank 13 is made of fiber-reinforced resin reinforced with carbon fiber or glass fiber, or the like. In this embodiment, three tanks 13 are fixed to the tank case 211 with the axial direction of their cylindrical portions parallel to the vehicle width direction. The number of tanks 13 is not limited to three.

[0043] The tank case 211 is a box that can accommodate one or more tanks 13. The tank case 211 has a box shape that completely covers the tanks 13 that it accommodates. The tank case 211 has an opening / closing door 213 (see FIG. 1 ) on one or both sides in the vehicle width direction, and is open in the vehicle width direction. The tank case 211 is installed above the roof 164 with a gap between it and the roof 164 in the vertical direction. The tank case 211 is fixed to the upper frame portion 171 of the mounting frame 17. The tank case 211 is made of metal such as aluminum or steel, and protects the tanks 13 from external thermal and physical influences.

[0044] The tank 13 is located above the cabin 16 (driver's seat 15). This allows for a high degree of freedom in the placement of the fuel cell 24, filling section 25, motor 31, and battery unit 30 in the vehicle body 11. When a conventional work vehicle with an internal combustion engine is modified to have a work vehicle 10 equipped with a fuel cell 24 and motor 31 as in this embodiment, there is no need to significantly change the placement and configuration of the various devices.

[0045] The tank 13 is connected to a rear pipe 22r and a front pipe 22f via a valve unit 212 (see FIG. 9). The rear pipe 22r (see FIG. 3) is a gas inlet pipe connecting the hydrogen gas fill port 26 and the valve unit 212, and guides hydrogen gas introduced into the fill port 26 to the tank 13. The front pipe 22f (see FIG. 2) is a gas outlet pipe connecting the fuel cell 24 and the valve unit 212, and guides hydrogen gas stored in the tank 13 to the fuel cell 24. The tank 13 stores hydrogen gas introduced into the fill port 26 from outside the vehicle and supplies it to the fuel cell 24. The valve unit 212 has an on-off valve, a pressure reducing valve, etc., and adjusts the hydrogen gas stored in the tank 13 to a predetermined flow rate and guides it to the fuel cell 24 through the front pipe 22f.

[0046] [Mounting Frame 17] The mounting frame 17 (see FIG. 1) is a frame structure for mounting the tank 13 on the vehicle body 11. The mounting frame 17 of this embodiment has an upper frame portion 171 that supports the tank 13, and a first front frame portion 172, a second front frame portion 175, and a rear frame portion 173 that serve as frames for supporting the upper frame portion 171. A tank case 211 is attached to the upper frame portion 171. In other words, the upper frame portion 171 supports the tank 13 via the tank case 211. The specific configuration of the mounting frame 17 will be described later.

[0047] A filling section 25 (see FIG. 3) is provided on the rear frame section 173. The filling section 25 has a gas filling port 26 to which a gas filling nozzle of a hydrogen gas supply device (not shown) installed outside the vehicle is connected when filling the tank 13 with hydrogen gas.

[0048] [Radiator] The work vehicle 10 (see FIGS. 4 and 5) has a cooling system that uses coolant to cool the fuel cell 24, motor 31, boost circuit 80, inverter 81, DC / DC converters 82, 83, etc. As part of the cooling system, the work vehicle 10 has a first radiator 48 and a second radiator 49. As shown in FIG. 9, the first radiator 48 is located in front of the fuel cell 24, and the second radiator 49 is located behind the fuel cell 24.

[0049] The first radiator 48 is a radiator for cooling devices other than the fuel cell 24. The second radiator 49 is a radiator for cooling the fuel cell 24. The first radiator 48 is connected to electrical components (heat-generating components) that require cooling, such as the motor 31, the boost circuit 80, the inverter 81, and the DC / DC converters 82 and 83, via a first cooling flow path (not shown) having a circulation pump. The first radiator 48 cools the coolant supplied through the first cooling flow path by heat exchange with external air. The second radiator 49 is connected to the fuel cell 24 via a second cooling flow path (not shown) having a circulation pump. The second radiator 49 cools the coolant supplied through the second cooling flow path by heat exchange with external air.

[0050] The first radiator 48 has a first fan 481. The second radiator 49 has a second fan 491. The first fan 481 and the second fan 491 rotate to pass air through the first radiator 48 and the second radiator 49, facilitating heat exchange with the coolant.

[0051] [Battery Unit 30] The battery unit 30 stores power to be supplied to the motor 31. The battery unit 30 (see FIG. 9 ) has a battery (battery pack) 300 and a housing 307 that houses the battery 300. The battery 300 temporarily stores the power generated by the fuel cell 24 and outputs the stored power to electrical devices such as the motor 31. The battery 300 is composed of multiple battery cells. The battery 300 is a charge-discharge type secondary battery such as a lithium-ion battery or a lead-acid battery.

[0052] [Electrical System] The work vehicle 10 has a junction box 75. The junction box 75 is an electrical connection box for relaying and distributing the power output from the battery unit 30. The fuel cell 24 is connected to an inverter 81 (see FIG. 5 ) via a boost circuit. The battery unit 30 is connected to the inverter 81 through the junction box 75. The inverter 81 is electrically connected to the motor 31. The inverter 81 converts the DC power output from the boost circuit into three-phase AC power and outputs it to the motor 31.

[0053] The work vehicle 10 has low-voltage electrical equipment that operates at a lower voltage than the motor 31. Power that has been stepped down by a step-down circuit is supplied to the low-voltage electrical equipment through a junction box 75. In the work vehicle 10 of this embodiment, the low-voltage electrical equipment is the battery unit 30, radiators 48, 49, and air conditioning unit 74. The work vehicle 10 has a first DC / DC converter 82 and a second DC / DC converter 83 as the step-down circuit.

[0054] [Regarding the Tank Case] ​​FIG. 10 is a schematic perspective view showing the tank case. FIG. 11 is an explanatory diagram of the installation of the tank case in a work vehicle. FIG. 12 is a schematic cross-sectional view of the tank and tank case. As shown in FIGS. 10 and 11 , the work vehicle 10 of the present disclosure includes a tank case 211. The tank case 211 is a substantially rectangular box-shaped body and includes a lower plate 221, a front plate 222, a rear plate 223, a left plate 224, a right plate 225, and an upper plate 226. The upper plate 226 includes a front upper plate 226a and a rear upper plate 226b. The front upper plate 226a has a downward slope toward the front side (X1 side). The rear upper plate 226b has a downward slope toward the rear side (X2 side). The tank case 211 is highest at a connection position 226c between the front upper plate 226a and the rear upper plate 226b. Therefore, if hydrogen leaks from inside the tank case 211, the hydrogen will naturally be collected below the connection position 226c.

[0055] 10 to 12 , the tank case 211 has a first vent 215 formed in the lower plate 221. Because the first vent 215 is open facing downward, even if rain falls on the tank case 211, there is a low possibility that the rain will enter the tank case 211 through the first vent 215. The first vent 215 is provided with a cover 235 that prevents insects and the like from entering. In the tank case 211 of the present disclosure, the first vent 215 is formed in the front end portion of the lower plate 221, but the position where the first vent 215 is formed is not limited thereto. For example, the first vent 215 may be formed in the rear end portion of the lower plate 221, or in both the front and rear ends of the lower plate 221.

[0056] In the tank case 211, rain that falls on the front upper plate 226a naturally flows down toward the front, and rain that falls on the rear upper plate 226b naturally flows down toward the rear. For this reason, rain is less likely to accumulate on the upper plate 226 of the tank case 211. Note that, although the work vehicle 10 of the present disclosure has the upper plate 226 of the tank case 211 inclined in the front-to-rear direction, the inclination direction of the upper plate 226 may also be in the left-to-right direction.

[0057] The tank case 211 has second ventilation holes 216 formed in the upper portions of the left side plate 224 and the right side plate 225. The height dimensions of the left side plate 224 and the right side plate 225 are greatest at the positions where they contact the connection position 226c.

[0058] When the tank case 211 is based on the tank 13 contained within the tank case 211, a lower plate 221 is arranged below the tank 13, a front plate 222 is arranged in front, a rear plate 223 is arranged behind, a left side plate 224 is arranged on the left side, a right side plate 225 is arranged on the right side, and an upper plate 226 is arranged above.

[0059] In the tank case 211, the first ventilation openings 215 are opened in the lower plate 221 at a position further below the tanks 13 housed in the tank case 211. In the tank case 211 of this embodiment, the first ventilation openings 215 are formed in two locations further forward than the frontmost tank 13, one near the left side plate 224 and the other near the right side plate 225.

[0060] In the tank case 211, the second ventilation openings 216 are opened in the left side plate 224 and the right side plate 225 at a position higher than the tank 13 housed in the tank case 211. The second ventilation openings 216 are opened at positions adjacent to connection positions 226c on the upper parts of the left side plate 224 and the right side plate 225. The second ventilation openings 216 are provided with mesh covers 236 that prevent the entry of insects and the like. The tank case 211 further includes a plurality of through holes 214 on the front side of the lower plate 221, through which the front piping 22f and wiring connected to the fuel cell 24 are passed. The tank case 211 further includes a through hole 219 on the lower right side of the rear side plate 223, through which the rear piping 22r is passed.

[0061] In the tank case 211 configured as described above, air flows in through the first ventilation opening 215, comes into contact with the tank 13, rises inside the tank case 211 by natural convection, and finally flows out to the outside through the second ventilation opening 216. This air flow not only ventilates the inside of the tank case 211 but also contributes to suppressing a rise in the temperature of the tank 13.

[0062] If hydrogen leaks inside the tank case 211, the hydrogen that naturally collects below the connection position 226c is efficiently discharged to the outside along the ventilation flow. Therefore, even if hydrogen leaks inside the tank case 211, the amount of hydrogen that accumulates inside can be kept small. In other words, the tank case 211 can quickly discharge hydrogen that has leaked inside the tank case 211 to the outside of the tank case 211 by using the air that naturally flows from the first ventilation port 215 to the second ventilation port 216.

[0063] The work vehicle 10 of the present disclosure further includes a hydrogen sensor 230 that detects leakage of hydrogen generated inside the tank case 211. The hydrogen sensor 230 is provided in a position adjacent to the second vent 216 inside the tank case 211. The hydrogen sensor 230 is preferably provided below the second vent 216 inside the tank case 211. In the event of a hydrogen leak inside the tank case 211, the leaked hydrogen rises inside the tank case 211 and naturally collects below the connection position 226c, and then flows out of the tank case 211 through the second vent 216. The hydrogen sensor 230, which is provided in a position below the second vent 216 and adjacent to the second vent 216, can reliably detect hydrogen just before it flows out of the tank case 211 through the second vent 216. Therefore, in the event of a hydrogen leak inside the tank case 211, the work vehicle 10 of the present disclosure can reliably detect the leaked hydrogen using the hydrogen sensor 230. Note that while the present embodiment illustrates an example in which the hydrogen sensor 230 is provided below and adjacent to the second vent 216, the placement of the hydrogen sensor 230 relative to the second vent 216 is not limited to this, and the hydrogen sensor 230 may be located to the side adjacent to the second vent 216 or above and adjacent to the second vent 216. As shown in the present embodiment, when the tank case 211 is provided with two second vents 216, it is preferable to place two hydrogen sensors 230 corresponding to the respective second vents 216. Note that while the work vehicle 10 of the present disclosure is provided with second vents 216 on both the left and right sides of the tank case 211, the work vehicle 10 of the present disclosure may have only one second vent 216.

[0064] [Openable / Closable Doors] As shown in FIGS. 10 to 13 , a portion of the left side panel 224 and a portion of the right side panel 225 of the tank case 211 are configured as openable / closable doors 213. The left side panel 224 is supported by the left side panel 224 via a plurality of hinges 217 so as to be openable and closable. The right side panel 213 is supported by the right side panel 225 via a plurality of hinges 217 so as to be openable and closable. Note that the entire left side panel 224 and the entire right side panel 225 of the tank case 211 may be configured as the openable / closable doors 213. Also, a portion of the front panel 222 and a portion of the rear panel 223 of the tank case 211 may be configured as the openable / closable doors 213. Note that, although the openable doors 213 open in the up-down direction in this embodiment, they may also open in the left-right direction.

[0065] The opening / closing door 213 is fixed (held in a closed state) to the left side plate 224 and the right side plate 225 with a single touch by a plurality of fixing brackets 218, and can also be opened with a single touch. The opening / closing door 213 of this embodiment is equipped with hinges 217 and fixing brackets 218, and can be opened and closed easily. In the work vehicle 10 of the present disclosure, the opening / closing door 213 may be bolted to the left side plate 224 and the right side plate 225 without using the hinges 217 and fixing brackets 218. In this case, the opening / closing door 213 can be closed by fastening the bolts, and can be opened by removing the bolts.

[0066] 13 , when the opening / closing door 213 that is part of the right side panel 225 of the tank case 211 is opened, the valve unit 212 appears in front of the user. Therefore, in the work vehicle 10 of the present disclosure, maintenance and inspection around the valve unit 212 can be easily performed by opening the right opening / closing door 213. Furthermore, the tank case 211 can open the opening / closing door 213 that is part of the left side panel 224. Therefore, in the work vehicle 10 of the present disclosure, by opening both the left and right opening / closing doors 213, it is possible to easily check the entire tank 13 and perform maintenance and inspection of the piping 22 (front piping 22f and rear piping 22r) provided around the tank 13.

[0067] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims.

[0068] REFERENCE SIGNS LIST 10 Work vehicle 11 Vehicle body 13 Tank (hydrogen tank) 15 Driver's seat 16 Cabin 22 Piping (hydrogen piping) 24 Fuel cell (fuel cell module) 31 Motor (electric motor) 211 Tank case 215 First vent 216 Second vent 221 Lower plate 222 Front side plate (third side plate) 223 Rear side plate (fourth side plate) 224 Left side plate (second side plate) 225 Right side plate (first side plate) 226 Upper plate 230 Hydrogen sensor

Claims

1. A work vehicle comprising: a vehicle body; a driver's seat, an electric motor, and a fuel cell module mounted on the vehicle body; a cabin arranged around the driver's seat; hydrogen piping and a hydrogen tank for supplying hydrogen to the fuel cell module; and a tank case arranged above the cabin and housing the hydrogen tank, wherein the tank case includes a lower plate that covers the hydrogen tank from below, side plates that cover the hydrogen tank from the sides, and an upper plate that covers the hydrogen tank from above, and has a first air vent opening in the lower plate.

2. A work vehicle as described in claim 1, wherein the tank case further has a second ventilation opening opening at an upper portion of the side panel.

3. A work vehicle as described in claim 2, further comprising a hydrogen sensor, said hydrogen sensor being disposed at a position adjacent to said second air vent inside said tank case.

4. A work vehicle as described in claim 2 or claim 3, wherein the upper plate is arranged at an incline relative to the lower plate, and the second air vent is opened in the upper part of the side plate adjacent to the position of the upper plate that is furthest from the lower plate.

5. A work vehicle as described in claim 2 or claim 3, wherein the tank case has the second ventilation opening in each of the two opposing side panels.

6. A work vehicle as described in claim 1, wherein the tank case has an opening and closing door that is supported on the side panel via a hinge so as to be able to be opened and closed.

7. A work vehicle as set forth in claim 6, wherein the hydrogen tank has a valve for adjusting the amount of hydrogen flowing in and out, and the opening and closing door is provided on a first side plate facing the valve.

8. A work vehicle according to claim 7, wherein the tank case has a second side plate parallel to the first side plate, and the opening and closing door is further provided on the second side plate.

9. A work vehicle as described in claim 6 or claim 7, wherein the upper plate of the tank case is inclined relative to the lower plate.

10. A work vehicle as described in claim 9, wherein the tank case has a third side plate and a fourth side plate perpendicular to the first side plate and the second side plate, and the upper plate has a downward inclination toward at least one of the third side plate and the fourth side plate.

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