Work vehicles

Abstract

To suppress any sense of unfamiliarity in operation of a work vehicle equipped with a fuel tank for a fuel cell. [Solution] By housing the power generation unit (106) of a fuel cell that generates electricity for the motor (101) within the hood (6) at the front of the vehicle body (1a), and arranging the fuel tanks (111, 111′, 141′) containing fuel for the fuel cell below the passenger compartment (7) where the worker sits and on both sides of the vehicle body (1a) in the horizontal direction, it is possible to suppress any sense of unnaturalness in operation in a work vehicle equipped with fuel tanks for a fuel cell.

Description

Technical Field

[0001] This invention relates to work vehicles such as tractors and control machines.

Background Art

[0002] In a work vehicle equipped with a working machine such as a tractor or a control machine, a technique of arranging a gas tank for a fuel cell stack below a cabin that houses a driver's seat to achieve weight balance is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, a plurality of gas tanks are arranged side by side between the cabin and the axle of the rear wheels. Therefore, the position of the entire cabin including the driver's seat moves upward. Therefore, compared with a work vehicle without a gas tank, the height of the driver's seat becomes higher. Thus, for an operator who operates multiple types of work vehicles, the line-of-sight height is different, and the operator is likely to feel discomfort during operation, and there are concerns such as operation errors.

[0005] An object of the present invention is to suppress the discomfort of operation in a work vehicle having a fuel tank for a fuel cell.

Means for Solving the Problems

[0006] The above problems of the present invention are solved by the following means. The invention described in claim 1 is a work vehicle comprising: a vehicle body (1a) having a front running gear (2) and a rear running gear (3,142); a front drive gearbox (102) that transmits power to the front running gear (2); a rear drive gearbox (103) that transmits power to the rear running gear (3,142); a motor (101) positioned between the front drive gearbox (102) and the rear drive gearbox (103) and transmitting power to the front drive gearbox (102) and the rear drive gearbox (103); a fuel cell power generation unit (106) housed in a hood (6) at the front of the vehicle body (1a) and generating electricity for the motor (101); and fuel tanks (111,111′,141′) positioned below the passenger compartment (7) on which an operator sits and on both sides of the vehicle body (1a) in the horizontal direction, and containing fuel for the fuel cell.

[0007] The invention described in claim 2 is the work vehicle according to claim 1, further comprising the fuel tank (111') arranged along a lateral direction intersecting the direction of travel of the vehicle body (1a).

[0008] The invention described in claim 3 is a work vehicle comprising: a vehicle body (1a) having a running gear (2, 3, 142); a motor (101) that drives the running gear (2, 3, 142); a fuel cell power generation unit (106) that generates electricity for the motor (101); and fuel tanks (131, 141) that are arranged parallel to the drive shafts (3a, 142a) of the running gear (2, 3, 142) and in the front and rear of the vehicle body (1a) in the direction of travel, and which contain fuel for the fuel cell.

[0009] The invention described in claim 4 is a work vehicle comprising: a vehicle body (1a) having a running gear (2,3,142,152); a motor (101) that drives the running gear (2,3,142,152); a fuel cell power generation unit (106) that generates electricity for the motor (101); a work machine (18) supported by the vehicle body (1a) and used for working in a field; and a fuel tank (121) arranged on the work machine (18) and containing fuel for the fuel cell. [Effects of the Invention]

[0010] According to the invention described in claim 1, by arranging the fuel tanks (111, 111′, 141′) containing fuel for the fuel cell below the passenger compartment (7) where the worker sits and on both sides of the vehicle body (1a) in the horizontal direction, it is possible to suppress any sense of unnaturalness in operation in a work vehicle equipped with a fuel tank for a fuel cell.

[0011] According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, by arranging the fuel tank (111') along a lateral direction intersecting the direction of travel of the vehicle body (1a), it is easier to balance the weight of the vehicle body (1a) from left to right.

[0012] According to the invention described in claim 3, by arranging the fuel tanks (131, 141) containing fuel for the fuel cell parallel to the drive shafts (3a, 142a) of the running gear (2, 3, 142) and in the front and rear directions of travel of the vehicle body (1a), it is possible to suppress any sense of unnaturalness in operation in a work vehicle having a fuel tank for a fuel cell.

[0013] According to the invention described in claim 4, by placing the fuel tank (121) containing fuel for the fuel cell on a work machine (18) that is supported by the vehicle body (1a) and performs work on the field, it is possible to suppress the feeling of unfamiliarity in operation of a work vehicle having a fuel tank for a fuel cell. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement has been lowered to the height at which work is performed. [Figure 2] Figure 2 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement is raised. [Figure 3] Figure 3 is a plan view of the main parts of the tractor according to this embodiment. [Figure 4]FIG. 4 is a schematic explanatory diagram of the pipe in the embodiment. FIG. 4(A) is an explanatory diagram of the fluid flowing through the pipe during operation, and FIG. 4(B) is an explanatory diagram of the fluid flowing through the pipe when the vehicle stops. [Figure 5] FIG. 5 is an explanatory diagram of the tractor according to another aspect 1 of the embodiment. [Figure 6] FIG. 6 is an explanatory diagram of the tractor according to another aspect 2 of the embodiment. [Figure 7] FIG. 7 is an explanatory diagram of the tractor according to another aspect 3 of the embodiment. [Figure 8] FIG. 8 is an explanatory diagram of the tractor according to another aspect 4 of the embodiment. [Figure 9] FIG. 9 is an explanatory diagram of the tractor according to another aspect 5 of the embodiment. [Figure 10] FIG. 10 is an explanatory diagram of the tractor according to another aspect 6 of the embodiment. [Figure 11] FIG. 11 is an explanatory diagram of the tractor according to another aspect 7 of the embodiment. [Figure 12] FIG. 12 is an explanatory diagram of the tractor according to another aspect 8 of the embodiment. [Figure 13] FIG. 13 is an explanatory diagram of the tractor according to another aspect 9 of the embodiment.

Mode for Carrying Out the Invention

[0015] FIG. 1 is an explanatory diagram of a tractor as an example of the work vehicle in the embodiment, and is an explanatory diagram of the state in which the working machine has descended to the height at which the work is performed. FIG. 2 is an explanatory diagram of a tractor as an example of the work vehicle in the embodiment, and is an explanatory diagram of the state in which the working machine has risen. In FIGS. 1 and 2, as an example of the work vehicle of the present invention, a tilling tractor 1 is provided with front wheels 2, 2 and rear wheels 3, 3 as an example of the traveling device at the front and rear parts of a traveling vehicle body (an example of the vehicle body) 1a. A hood (bonnet) 6 is provided at the front part of the traveling vehicle body 1a, and a transmission case 5 having a transmission device is provided at the rear part of the traveling vehicle body 1a. Further, at the rear part of the tractor body, a working machine such as a tiller (an example of a working machine, a rotary tiller) 18 for tilling the ground (field) behind the tractor 1 is mounted, and power is transmitted via a PTO shaft 9 to drive the working machine. In this specification, the left and right sides are respectively referred to as the left side and the right side toward the forward direction of the tractor 1, the forward direction is referred to as the front side, and the reverse direction is referred to as the rear side.

[0016] On the upper part of the traveling vehicle body 1a, a cabin 7 as an example of a riding part is supported. Inside the cabin 7, a driver's seat 8 is arranged at the upper position of the transmission case 5, and in front of this driver's seat 8, a steering wheel 10, a parking brake (not shown), etc. are arranged. Further, in front of the driver's seat 8, a display panel (meter panel) such as a speed meter (not shown) and various operation switches (not shown) are arranged. At the lower front part of the driver's seat 8, traveling operation tools such as a brake pedal 12 and an accelerator pedal 13 are arranged.

[0017] In FIG. 1, a hydraulic cylinder case 14 is provided above the rear part of the transmission case 5, and lift arms 15, 15 are pivotally attached to be rotatable on both the left and right sides of this hydraulic cylinder case 14. Lift rods 17, 17 are interposed and connected between the lift arms 15, 15 and the lower links 16, 16, and a tiller 18 is connected to the rear parts of the lower links 16, 16.

[0018] When hydraulic fluid is supplied to the hydraulic cylinder 14a housed in the hydraulic cylinder case 14, the lift arms 15, 15 are rotated upward, and the tiller (working implement) 18 rises via the lift rod 17, lower link 16, etc. Conversely, when the hydraulic fluid in the hydraulic cylinder 14a is discharged into the transmission case 5, which also serves as a hydraulic tank, the lift arms 15, 15 descend. Furthermore, the implements attached to the rear of the vehicle body 1a, that is, the implements to which power is transmitted from the PTO shaft 9, are not limited to rotary tillers for agricultural work, but may include plows, seeders, seedling transplanters, fertilizer spreaders, pesticide sprayers, and other implements.

[0019] Figure 3 is a plan view of the main parts of the tractor according to this embodiment. In Figure 3, in the tractor 1 of this embodiment, a motor 101, as an example of a drive source, is positioned in the center of the vehicle body 1a. The motor 101 is housed inside the transmission case 5. In front of the motor 101, a front drive gearbox 102 is positioned along the axle (drive shaft) 2a of the front wheel 2. The front drive gearbox 102 receives the drive from the motor 101, reduces and branches the transmitted drive, and transmits it to the front wheel 2 (an example of the front running gear).

[0020] Behind the motor 101, a rear drive gearbox 103 is positioned along the axle (drive shaft) 3a of the rear wheel 3. The rear drive gearbox 103 receives power from the motor 101, reduces and branches the transmitted power, and transmits it to the rear wheel 3 (an example of the rear running gear). In this embodiment, the rear drive gearbox 103 is housed in a transmission case 5. Therefore, in the tractor 1 of this embodiment, one motor 101 drives both the front wheels 2 and the rear wheels 3. By using one motor (a motor with two shafts extending from front to rear), the element of eccentricity during driving is reduced compared to using two motors, and a reduction in vibration can be expected.

[0021] In this embodiment, a configuration in which the front wheels 2 and rear wheels 3 are driven by a single motor 101 is illustrated, but the system is not limited to this. It is also possible to drive the front wheels 2 and rear wheels 3 with separate motors. When separate motors are used, it is easy to switch between four-wheel drive (4WD) and two-wheel drive (2WD) by switching each motor on and off. Furthermore, if the rotational speeds of the front wheels 2 and rear wheels 3 differ significantly, this can be easily handled by differentiating the rotational speeds of each motor. Alternatively, a clutch can be provided between one motor 101 and each gearbox 102, 103 to control power transmission. When a clutch is provided, the load on the motor can be reduced by disengaging the clutch during rapid deceleration.

[0022] In Figures 1 and 2, a battery 104 that supplies power to electronic devices such as the motor 101 is housed inside the hood 6. Also inside the hood 6, next to the battery 104, is an FC (Fuel Cell) stack 106, which is an example of a fuel cell power generation unit. By mounting the FC stack 106 and battery 104 in the same position as the engine in conventional models, the weight balance of the tractor 1 can be made to be similar to that of conventional tractors. Therefore, it is possible to minimize the impact on the operator's feel during operation (steering feel). Inside the hood 6, a cooling fan 107 is installed in front of the battery 104 and FC stack 106 to cool the FC stack 106 and other components. By installing the cooling fan 107 in the same position as the radiator in conventional tractors, the weight balance of the tractor 1 can be made to be similar to that of conventional tractors. Furthermore, the shape of the hood 6 can be reused from that of conventional tractors, which is expected to reduce costs associated with mass production.

[0023] Fuel tanks 111 containing hydrogen, an example of fuel for a fuel cell, are positioned on both the left and right sides of the vehicle body 1a in the horizontal direction. In this embodiment, the fuel tanks 111 are located below the cabin 7 and between the axle 2a of the front wheel 2 and the axle 3a of the rear wheel 3. In particular, the fuel tanks 111 in this embodiment are positioned on both sides (left and right) in the horizontal direction relative to the motor 101. Furthermore, the left and right fuel tanks 111 have a shape that extends in the front-to-back direction.

[0024] Figure 4 is a schematic diagram illustrating the piping in the embodiment, where Figure 4(A) is an explanatory diagram of the fluid flowing through the piping during operation, and Figure 4(B) is an explanatory diagram of the fluid flowing through the piping when the vehicle is stopped. In Figure 4, the fuel tank 111 is connected to the FC stack 106 by piping 112. The piping 112 in this embodiment includes a fuel pipe 112a connecting the fuel tank 111 and the FC stack 106, an outside air pipe 112b connecting the outside air and the FC stack 106, a scavenging pipe 112c connecting the fuel pipe 112a and the outside air pipe 112b, and a drain pipe 112d for discharging water generated in the FC stack 106. A switching valve 113 is located at the connection between the fuel pipe 112a and the scavenging pipe 112c, and an intake pump 114 is located in the outside air pipe 112b.

[0025] In Figure 4(A), during operation, the switching valve 113 connects the fuel tank 111 and the FC stack 106, and the fuel pipe 112a and the scavenging pipe 112c are shut off, supplying fuel (hydrogen) from the fuel tank 111 to the FC stack 106. At this time, the intake pump 114 also operates, and outside air containing oxygen is transferred to the FC stack 106. In the FC stack 106, electricity is generated by the reaction of hydrogen and oxygen, and water and nitrogen from the outside air are discharged (drained, exhausted) through the drain pipe 112d. In Figure 4(B), when the vehicle is stopped, the switching valve 113 switches, connecting the scavenging pipe 112c to the FC stack 106. Therefore, the fuel tank 111 and the FC stack 106 are shut off, and fuel is not supplied to the FC stack 106. When the intake pump 114 operates, outside air is sent into the fuel pipe 112a between the switching valve 113 and the FC stack 106, and hydrogen in this area is exhausted. If hydrogen remains stagnant, there is a risk of damage to parts due to hydrogen embrittlement and fire, but in this embodiment, hydrogen is scavenged through the scavenging pipe 112c, suppressing the risk of hydrogen embrittlement and fire.

[0026] While the example given illustrates the outside air piping 112b drawing in outside air, the system is not limited to this configuration. For example, if an air conditioner is installed in the cabin 7, the system can also draw in air from the cabin 7. The FC stack 106 becomes hot during power generation and it is desirable to cool it down. In hot weather, such as during summer, the outside air is also hot, and drawing in outside air reduces the cooling effect on the FC stack 106. However, by sending air from the cabin 7, which has been cooled by the air conditioner, to the FC stack 106, the cooling effect of the FC stack 106 can be enhanced. It is also preferable to have a system that allows switching between the cabin 7 and outside air as the source of air intake to the FC stack 106.

[0027] Furthermore, the outer end of the drainage pipe 112d can be configured to drain water downwards into the field, but is not limited to this configuration. When the FC stack 106 becomes hot, the drained water also becomes hot, and if crops are planted in the field, the hot water may come into contact with the crops, potentially negatively affecting their growth. To address this, it is possible to connect a tank to the outer end of the drainage pipe 112d to store the water from the FC stack 106 in the tank and prevent it from being drained into the field. It is also preferable to have a valve that allows switching between storing the water in the tank and draining it into the field, so that the water is discharged into the field when there are no crops (such as tilling) and stored in the tank when there are crops (such as fertilizing or spraying pesticides). In this case, it is also possible to equip the tractor 1 with a camera to capture images of the field, determine the presence and growth status of crops from the images, and automatically switch between discharging the water into the field and storing it in the tank based on the determination result. Furthermore, it is preferable to switch to storing the water in a tank when the video footage detects the presence of a person, in order to prevent the hot water from splashing on the person.

[0028] In the tractor 1 of the embodiment having the above configuration, the fuel tanks 111 are located below the cabin 7 and on both the left and right sides of the vehicle body 1a. Therefore, compared to the conventional technology in which the fuel tank is located between the vehicle body and the cabin, the cabin 7 can be installed at a lower position, and the height of the cabin 7 does not need to be increased. Therefore, for workers operating multiple types of work vehicles, the eye level is more easily aligned, and discomfort during operation is reduced. Consequently, concerns such as operational errors, control errors, and judgment errors can be suppressed. Furthermore, in this embodiment, the cabin 7 can be installed at a lower position, making it possible to lower the overall center of gravity of the tractor 1 compared to the configuration described in Patent Document 1. Consequently, the tractor 1 is easier to drive and less likely to tip over, improving drivability and work efficiency.

[0029] Figure 5 is an explanatory diagram of another embodiment of the tractor. As shown in Figure 5, it is also possible to arrange fuel tanks 111' that extend in the left-right direction below the cabin 7 and on both the left and right sides of the vehicle body 1a. In the configuration shown in Figure 5, multiple fuel tanks 111' that extend in the left-right direction are arranged in a front-to-back line between the axle 2a of the front wheel 2 and the axle 3a of the rear wheel 3. By arranging the fuel tanks 111' in a left-to-right line, the left-to-right balance of the tractor 1's center of gravity is more easily stabilized. In addition, it is easier to replace the fuel tanks 111' during maintenance. In particular, the fuel tanks 111' in the configuration shown in Figure 5 are short in length, and it is possible to replenish the gas by replacing the entire fuel tank 111' when refueling.

[0030] Figure 6 is an explanatory diagram of another embodiment of the tractor. In the embodiment shown in Figure 3, the fuel tanks 111 are arranged on both the left and right sides of the vehicle body 1a, but the invention is not limited to this. As shown in Figure 6, it is also possible to arrange the fuel tanks 111'' below the cabin 7 and the motor 101, that is, below the cabin 7 and below the vehicle body 1a. In Figure 6, the fuel tanks 111'' are formed in a shape that extends in the left-right direction. Furthermore, multiple fuel tanks 111'' that extend in the left-right direction are arranged in a front-to-back line between the axle 2a of the front wheel 2 and the axle 3a of the rear wheel 3. By arranging the fuel tanks 111'' in a left-to-right line, the left-to-right balance of the tractor 1 is more easily stabilized. In addition, it is easier to replace the fuel tanks 111''.

[0031] Figure 7 is an explanatory diagram of another embodiment 3 of the tractor. Furthermore, as shown in Figure 7, it is also possible to position the fuel tank 121 on top of the tiller (working machine) 18. In the configuration shown in Figure 7, the fuel tank 121 can be installed in an open space, and the fuel tank 121 can be made larger. As an example, the piping from the fuel tank 121 to the FC stack 106 can be done via the lower link 16.

[0032] Figure 8 is an explanatory diagram of another embodiment of the tractor (Embodiment 4). Furthermore, as shown in Figure 8, the fuel tank 131 can be positioned parallel to the axle 3a of the rear wheel 3 and in front of or behind the axle 3a with respect to the direction of travel of the vehicle body 1a. In the configuration shown in Figure 8, it is possible to suppress an increase in the height of the cabin 7.

[0033] Figure 9 is an explanatory diagram of another embodiment of the tractor (5). As shown in Figure 9, in a semi-crawler type tractor 1 having a continuous track type running device, so-called crawler 142, instead of rear wheels 3, it is also possible to position a fuel tank 141 that extends in the left-right direction near the drive shaft 142a of the crawler 142 and in the gap inside the crawler belt 142b. In the configuration shown in Figure 9, the space inside the crawler 142 can be effectively utilized, and the height of the cabin 7 can be kept from increasing.

[0034] Figure 10 is an explanatory diagram of another embodiment of the tractor (6). As shown in Figure 10, it is also possible to position a fuel tank 141' extending along the surface of the crawler belt 142b at the gap between the outer surface of the crawler belt 142b and the inside of the fender 144. Therefore, a pair of fuel tanks 141' are arranged on the left and right sides. In the configuration shown in Figure 10, the gap between the crawler 142 and the fender 144 can be effectively utilized, and the height of the cabin 7 can be kept from increasing.

[0035] Figure 11 is an explanatory diagram of another embodiment of the tractor 7. Figure 12 is an explanatory diagram of another embodiment of the tractor (8). As shown in Figure 11, in a full-crawler type tractor 1 having a continuous track type running gear (full crawler) 152 instead of front wheels 2 and rear wheels 3, it is also possible to arrange a fuel tank 161 in the space between the cabin 7 and the full crawler 152 below the rear fender 144, extending in the left-right direction (parallel to the drive shaft of the full crawler 152). Alternatively, as shown in Figure 12, the fuel tank 171 can be positioned in the space above the full crawler 152 on the lower side of the cabin 7, extending in the front-rear direction. In the configurations shown in Figures 11 and 12, the space above the full crawler 152 can also be effectively utilized.

[0036] Figure 13 is an explanatory diagram of another embodiment of the tractor 9. As shown in Figure 13, in a tractor 1 having a safety frame (LOPS) 181, it is also possible to arrange a fuel tank 183 in the space between the seat 182 and the safety frame 181 so as to extend in the left-right direction.

[0037] In the above embodiment, a tractor 1 was used as an example of a work vehicle, but it is not limited to this. It can be applied to any work vehicle equipped with work implements, such as a rice transplanter, lawnmower, seedling transplanter, vegetable harvester, combine harvester, etc. [Explanation of Symbols]

[0038] 1. Work vehicles, 1a Vehicle body, 2. Front running gear, 2,3,142,152 Running gear, 3,142 Rear running gear, 3a,142a Drive shaft, 6 Food, 7 Boarding area, 18 work machines, 101 motor, 102 Front drive gearbox, 103 Rear drive gearbox, 106 Power generation section of fuel cell, 111, 111′, 111″, 121, 131, 141, 141′, 161, 171, 183 Fuel tanks.

Claims

1. A vehicle body (1a) having a front running gear (2) and a rear running gear (3,142), A front drive gearbox (102) that transmits power to the front running gear (2), A rear drive gearbox (103) that transmits power to the aforementioned rear running gear (3,142), A motor (101) is positioned between the front drive gearbox (102) and the rear drive gearbox (103) and transmits power to the front drive gearbox (102) and the rear drive gearbox (103), The fuel cell power generation unit (106) is housed within the hood (6) at the front of the vehicle body (1a) and generates electricity for the motor (101), Below the passenger compartment (7) where the worker sits and on both sides of the vehicle body (1a) in the horizontal direction, are fuel tanks (111, 111', 141') containing fuel for the fuel cell, A work vehicle equipped with [a specific feature / equipment].

2. The fuel tank (111') is arranged along the transverse direction intersecting the direction of travel of the vehicle body (1a), A work vehicle according to claim 1, comprising:

3. A vehicle body (1a) having running gear (2, 3, 142), A motor (101) that drives the aforementioned traveling device (2, 3, 142), The fuel cell power generation unit (106) generates power for the motor (101), Fuel tanks (131, 141) containing fuel for the fuel cell are arranged parallel to the drive shafts (3a, 142a) of the aforementioned running gear (2, 3, 142) and in the front and rear directions of travel of the vehicle body (1a), A work vehicle equipped with [a specific feature / equipment].

4. A vehicle body (1a) having running gear (2, 3, 142, 152), A motor (101) that drives the aforementioned traveling devices (2, 3, 142, 152), The fuel cell power generation unit (106) generates power for the motor (101), A work machine (18) supported by the vehicle body (1a) and used for working in the field, A fuel tank (121) is placed in the aforementioned work machine (18) and contains fuel for the fuel cell, A work vehicle equipped with [a specific feature / equipment].

Images