Fuel tank system and work vehicle

Abstract

The utility model provides a kind of fuel tank system, the fuel tank is installed on work vehicle, the fuel tank system has: fuel tank, air vent and fuel supply port are provided in the top surface of the fuel tank;First pipe, the first end of the first pipe is connected with the fuel supply port side in the fuel tank, the second end of the first pipe is connected with the air vent in the fuel tank;Second pipe, the first end of the second pipe is open to atmosphere, the second end of the second pipe is connected with the air vent and check valve, install between the first end and the second end of the second pipe.The utility model not only can prevent fuel in fuel tank from leaking when work vehicle is inclined or turned over, i.e. fuel tank is inclined or turned over, but also can prevent fuel tank from inhaling external air into fuel tank when becoming negative pressure, avoid fuel tank from being deformed due to atmospheric pressure, piping is sucked flat to block oil path and other problems.

Description

Technical Field

[0001] This utility model relates to a fuel tank system for a work vehicle and the work vehicle itself. Background Technology

[0002] Typically, fuel tanks are installed on tractors and other work vehicles. When the tractor tilts or tipes over, fuel may leak from the fuel tank. Therefore, before installing the fuel tank on the work vehicle, a fuel tank tip-over leak test is required. This test involves filling the fuel tank with water and covering it with a lid, then tipping the fuel tank over to confirm whether the water leakage is below a reference value. Additionally, the fuel tank becomes under negative pressure when using fuel and pressurizes during fuel supply, preventing it from filling completely. Fuel tanks usually have vents to the atmosphere to prevent negative pressure and to prevent internal pressurization during fuel supply, ensuring the tank is full. However, preventing fuel leakage from the vent during the fuel tank tip-over leak test remains a crucial challenge.

[0003] Previously, to prevent fuel leakage from the fuel tank's vent, a vent hole was provided on the vent's cover. This vent hole allowed air to be drawn into the fuel tank but prevented water leakage. However, this structure had the following problems: fuel leakage could occur due to misalignment of the vent hole, making it difficult to achieve stability.

[0004] Furthermore, to prevent fuel leakage from the fuel tank's vent, the following structure is employed: a valve is installed on the piping connected to the vent, which closes when the fuel tank is tilted at a certain angle. Under normal use, air is allowed to be drawn into the fuel tank, but fuel does not leak from the tank during a fuel tank tilting leak test. While such a valve prevents fuel leakage, it is typically expensive, increasing overall costs. Additionally, such valves are relatively large, making installation space difficult to secure. Utility Model Content

[0005] This utility model provides a fuel tank system and a working vehicle equipped with the fuel tank system, which prevents fuel flowing out of the vent from leaking to the outside when tilted or overturned and returns the fuel to the fuel tank to avoid waste, and prevents the fuel tank from becoming negative pressure during operation. The system has a simple structure and low cost.

[0006] This invention provides a fuel tank system, which is installed on a work vehicle.

[0007] The fuel tank system has:

[0008] A fuel tank, with a vent and a fuel supply port provided on its top surface;

[0009] A first piping, the first end of which is connected to the fuel supply port side in the fuel tank, and the second end of which is connected to the vent in the fuel tank;

[0010] The second piping has a first end open to the atmosphere and a second end connected to the vent.

[0011] A check valve is installed between the first end and the second end of the second piping.

[0012] According to the fuel tank system of this utility model, by installing a check valve between the first and second ends of the second piping, it can prevent fuel leakage from the vent to the outside when the fuel tank is tilted or tipped over, and return the fuel to the fuel tank to avoid waste. Furthermore, the check valve opens to draw in air when the pressure difference between the inside and outside of the fuel tank exceeds a certain value, thereby preventing the fuel tank from becoming negatively pressured during operation. Moreover, the fuel tank system has a first piping, a second piping, and a check valve; therefore, the fuel tank system has a simple structure, excellent stability, and low cost.

[0013] Preferably, the top surface of the fuel tank includes a first region with the fuel supply port, a region with the vent, and a third region other than the first and second regions, wherein the height of the first and second regions is higher than the height of the third region.

[0014] According to the fuel tank system of this utility model, the top surface of the fuel tank includes a first region with the fuel supply port, a region with the vent, and a third region other than the first and second regions. The height of the first and second regions is higher than the height of the third region, thus increasing the design freedom of the fuel tank and increasing its volume to store more fuel.

[0015] Preferably, the first region is located on one side of the top surface of the fuel tank, and the second region is located on the other side of the top surface of the fuel tank, separated from the third region.

[0016] According to the fuel tank system of this utility model, the first region is located on one side of the top surface of the fuel tank, and the second region is located on the other side of the top surface of the fuel tank, separated by the third region. Therefore, the distance between the fuel supply port and the vent can be maximized, which is beneficial for setting other components between the two ends and can make full use of the setting space to make the structure compact.

[0017] Preferably, the second end of the first pipe and the second end of the second pipe are directly connected to the vent.

[0018] The fuel tank system according to this utility model can make the structure of the fuel tank system simpler and the manufacturing cost lower.

[0019] Preferably, the fuel tank system further comprises: a third piping, the first end of which is connected to the vent.

[0020] The second ends of the first pipe, the second pipe, and the third pipe are connected to each other in a T-shape.

[0021] The fuel tank system according to this utility model allows for more flexible structural design and easier assembly of the fuel tank system.

[0022] Preferably, the second end of the first pipe, the second end of the second pipe, and the second end of the third pipe are connected via a T-shaped tee connector.

[0023] The fuel tank system according to this utility model makes the assembly of the fuel tank system more convenient.

[0024] Preferably, the T-shaped three-way connector is located between the check valve and the vent.

[0025] According to the fuel tank system of this utility model, the check valve and the vent can be easily connected.

[0026] Preferably, a cover for the second piping, allowing air to enter, is installed at the first end of the second piping.

[0027] The fuel tank system according to this utility model can ensure that air enters the second piping while preventing dust, rainwater, etc. from entering and clogging the second piping.

[0028] Preferably, the first end of the second conduit is inverted U-shaped.

[0029] The fuel tank system of this invention can, with its simple structure, ensure air enters the second piping while preventing dust, rainwater, and other contaminants from entering and clogging the second piping.

[0030] Preferably, the first end of the first piping is connected to the fuel supply port.

[0031] According to the fuel tank system of this utility model, the first end of the first pipe is connected to the fuel supply port, which can maximize the volume of fuel in the fuel tank.

[0032] This utility model also provides a work vehicle having the above-described fuel tank system. Attached Figure Description

[0033] Figure 1 This is a side view of a work vehicle equipped with a fuel tank system.

[0034] Figure 2 This is a side view showing the fuel tank system of the work vehicle.

[0035] Figure 3 This is a side view showing the air movement path when the fuel tank system of the work vehicle supplies fuel.

[0036] Figure 4 This is a side view showing the fuel tank of the work vehicle at the end of its fuel supply system.

[0037] Figure 5 This is a side view showing another fuel tank system of the work vehicle.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1: Operating vehicle; 2: Vehicle body; 3: Front wheel; 4: Rear wheel; 5: Step; 10: Driver's seat; 11: Driver's seat; 12: Steering handle; 15: Protective structure; 20: Fuel tank system; 21: Fuel tank; 211: Fuel supply port; 212: Vent; 22: First piping; 23: Second piping; 24: Third piping; 25: T-type tee connector; 26: U-shaped component; 27: Check valve; 28: Liquid level. Detailed Implementation

[0040] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the dimensions or quantities of various parts are exaggerated or simplified as needed for ease of understanding. Additionally, parts with the same structure and function are labeled with the same reference numerals, and repeated descriptions are omitted in the following description.

[0041] Furthermore, in the following description, the same reference numerals are used to illustrate the same constituent elements, and their names and functions are also set to be the same. Therefore, detailed descriptions of them are sometimes omitted to avoid repetition.

[0042] Furthermore, in the following description, even when ordinal numbers such as "first" or "second" are used, these terms are used for convenience and to facilitate understanding of the embodiments, and are not limited to the order that can be generated by these ordinal numbers.

[0043] When an expression using "including," "having," "possessing," "comprises," or "has" a constituent element is used, the expression is not an exclusive expression excluding the existence of other constituent elements. When an expression using "at least one of A, B, and C" is used, the expression indicates that it includes only A, only B, only C, any two of A, B, and C, or all of A, B, and C.

[0044] The preferred embodiments of the present invention will be described below based on the accompanying drawings.

[0045] Figure 1 This is a side view of the work vehicle 1 equipped with a fuel tank. Figure 2 This is a side view showing the fuel tank system 20 of the work vehicle 1. Figure 3 This is a side view showing the air movement path when the fuel tank system 20 of the work vehicle 1 supplies fuel. Figure 4 This is a side view showing the fuel tank of the work vehicle 1 at the end of fuel supply to the fuel tank system 20. Figure 5 This is a side view showing another fuel tank system 20 of the work vehicle 1.

[0046] In this disclosure, "operation vehicle 1" refers to a vehicle (vehicle) used for performing operations at a work site. Operation vehicle 1 can be, for example, agricultural machinery, where "agricultural machinery" refers to machinery used for agricultural purposes. Examples of agricultural machinery include tractors, harvesters, rice transplanters, passenger management machines, vegetable transplanters, lawn mowers, seeders, fertilizer applicators, and mobile robots for agricultural use.

[0047] <Basic Structure of Operation Vehicle 1>

[0048] First, examples of the basic structure and operation of the work vehicle 1 disclosed herein will be explained.

[0049] Figure 1 This is a side view schematically illustrating an example of the basic structure of the work vehicle 1 of this disclosure. In this disclosure, the direction of travel when the work vehicle 1 travels straight forward is called the "forward direction," and the direction of travel when traveling straight backward is called the "rearward direction." In a plane parallel to the ground, the direction extending perpendicularly to the right relative to the "forward direction" is called the "right direction," and the direction extending perpendicularly to the left relative to the "forward direction" is called the "left direction." In a plane perpendicular to the ground, the direction extending perpendicularly upward relative to the "forward direction" is called the "upward direction," and the direction extending perpendicularly downward relative to the "forward direction" is called the "downward direction." Figure 1 In the diagram, the "forward," "backward," "right," and "left" directions, as well as the "up" and "down" directions, are represented by arrows pointing forward, backward, right, left, up, and down, respectively. Sometimes, the forward and backward directions are collectively referred to as the "front-back direction," the right and left directions as the "width direction," and the up and down directions as the "height direction."

[0050] Figure 1 The work vehicle 1 in the example shown is, for example, a tractor, which is an example of agricultural machinery. The technology disclosed herein is not limited to work vehicles 1 such as tractors, but can also be applied to other types of work vehicles 1.

[0051] The work vehicle 1 has a pair of front wheels 3 and a pair of rear wheels 4 on the left and right sides, which are capable of being driven and steered, on the body 2, which serves as a frame structure. A cab 10 for the driver to sit in and operate the vehicle is located above the center of the body 2. A loading platform for loading and unloading goods can be installed at the rear of the body 2. The cab 10, located in the center of the body 2, is surrounded by a protective structure 15.

[0052] The driver's cab 10 is equipped with a driver's seat 11 for passengers to sit in, a steering handle 12 for steering the front wheels 3, a gear shift lever (not shown) for shifting gears, an accelerator pedal (not shown), etc.

[0053] Furthermore, as a power system element, it includes an internal combustion engine (hereinafter referred to as an engine) such as a gasoline engine or a diesel engine, and a transmission device that transmits the engine's output to the front wheels 3 and rear wheels 4 by changing the speed. Since the structure of the transmission device is prior art, it will not be described in detail, but by operating the gear lever, multiple gear ratios can be generated. The power output from the transmission device to the rear wheels is transmitted to the left and right rear wheels 4 via the rear differential. The power output from the transmission device to the front wheels is transmitted to the left and right front wheels 3 via the driveshaft and the front differential.

[0054] A step 5 is provided below the cab 10 to facilitate the vehicle operator's entry and exit.

[0055] The work vehicle 1 is equipped with a fuel tank system 20 (see reference). Figure 2 The fuel tank system 20 has a fuel tank 21.

[0056] Step 5 can be located below the cab 10 and above the fuel tank 21.

[0057] An engine is located near the fuel tank 21. The engine and the fuel tank 21 are connected via a fuel supply pipe. The fuel tank 21 is located below the driver's seat 10, and more specifically, at least a portion of the fuel tank 21 is located below the step 5. Fuel in the fuel tank 21 is supplied to a fuel injection device (not shown) via the fuel supply pipe. Fuel is injected through the fuel injection device into the engine intake manifold and supplied to the combustion chamber within the engine cylinders.

[0058] like Figure 2As shown, the fuel tank 21 is generally rectangular in shape and has a top plate, side plates, and a bottom plate. The top plate of the fuel tank 21 forms the top surface of the fuel tank and is generally flat. A fuel supply port 211 is provided on the top surface of the fuel tank 21. A vent 212 is also provided on the top surface of the fuel tank 21. More specifically, the top surface of the fuel tank 21 includes a first region with the fuel supply port 211, a second region with the vent 212, and a third region outside the first and second regions, wherein the height of the first and second regions is greater than the height of the third region.

[0059] The first region is located on one side of the top surface of the fuel tank 21, and the second region is located on the other side of the top surface of the fuel tank 21, separated by the third region. More specifically, the first region is located on one side of the top surface of the fuel tank 21, i.e., the side facing the vehicle's direction of travel, and the second region is located on the other side of the top surface of the fuel tank 21, i.e., the other side facing the vehicle's direction of travel, separated by the third region. Alternatively, in this embodiment, the first region may also be located on the other side of the top surface of the fuel tank 21, and the second region may also be located on one side of the top surface of the fuel tank 21, separated by the third region.

[0060] The first and second regions are not limited to being located on one side and the other side of the top surface of the fuel tank 21; they can be located at other parts of the top surface of the fuel tank 21. For example, they can be located on the left or right sides of the top surface of the fuel tank 21, or near the center. This increases the design freedom of the fuel tank and allows for a larger volume to store more fuel. Of course, the shape of the top surface of the fuel tank 21 is not limited to a flat plate; it can also be concave-convex, V-shaped, or other shapes.

[0061] A cover is provided on the fuel supply port 211 to open and close the fuel supply port 211. The cover opens the fuel supply port 211 when fuel is supplied to the fuel tank and closes the fuel supply port 211 after the fuel supply is completed.

[0062] In this embodiment, as Figure 1 , 2 As shown, since the height of the first region with the fuel supply port 211 and the second region with the vent 212 on the top surface of the fuel tank 21 is higher than the height of the third region on the top surface of the fuel tank 21, and the step 5 is located between the first region on one side of the top surface of the fuel tank 21 and the second region on the other side of the top surface of the fuel tank 21, not only can the structure of the fuel tank 21 and the step 5 be made compact, but the volume of the fuel tank can also be maximized.

[0063] In embodiments of this utility model, such as Figure 2As shown, the fuel tank system 20, in addition to the fuel tank 21, also includes a plurality of pipes. The plurality of pipes includes a first pipe 22, a second pipe 23, and a third pipe 24. The first pipe 22 extends in a direction substantially parallel to the top surface of the fuel tank 21, or it may extend in a direction intersecting the top surface of the fuel tank 21. The first pipe 22 includes a first end and a second end. The first end of the first pipe 22 is connected to the fuel supply port 211 of the fuel tank 21, or the first end is connected to the fuel supply port 211 of the fuel tank 21, and the second end of the first pipe 22 is connected to the vent 212. For example, as... Figure 2 As shown, the first end of the first pipe 22 is connected to the fuel supply port 211, and the second end of the first pipe 22 is connected to the vent 212 via the T-junction 25 (described later) and the third pipe 24. The second pipe 23 extends in a direction substantially perpendicular to the top surface of the fuel tank 21, or it may extend in a direction intersecting the direction substantially perpendicular to the top surface of the fuel tank 21. The second pipe 23 includes a first end and a second end. The first end of the second pipe 23 is open to the atmosphere, and the second end of the second pipe 23 is connected to the vent 212. Furthermore, as... Figure 2 As shown, the second end of the second piping 23 is connected to the vent 212 via the T-shaped tee connector 25 and the third piping 24, which will be described later.

[0064] like Figure 2 As shown, a check valve 27 may also be provided on the fuel tank system 20. The check valve 27 is installed between the first end and the second end of the second piping 23. When the fuel tank 21 is under negative pressure, the check valve 27 allows air to enter the fuel tank 21, but prevents fuel from leaking from the fuel tank 21 when the fuel tank 21 is tilted or tipped over. Here, "between" refers to "between in the flow direction".

[0065] like Figure 2 As shown, the third pipe 24 extends in a direction substantially perpendicular to the top surface of the fuel tank 21, or it may extend in a direction intersecting the direction substantially perpendicular to the top surface of the fuel tank 21. The third pipe 24 includes a first end and a second end. The first end of the third pipe 24 is connected to the vent 212, and the second end of the third pipe 24 is connected to the first pipe 22 and the second pipe 23. The second ends of the first pipe 22, the second pipe 23, and the third pipe 24 are connected to each other in a T-shape.

[0066] In this embodiment, the fuel tank system 20 also includes a T-junction 25. The T-junction 25 connects a plurality of pipes. The second ends of the first pipe 22, the second pipe 23, and the third pipe 24 are connected via the T-junction 25, thereby facilitating the assembly of the fuel tank system. The T-junction 25 is located between the check valve 27 and the vent 212, thereby allowing for easy connection between the check valve 27 and the vent 212. Here, "between" refers to "between in the flow path direction".

[0067] In this embodiment, the first end of the second conduit 23 is inverted U-shaped. For example, the inverted U-shape can be achieved using an inverted U-shaped component 26, which can be installed separately on the first end of the second conduit 23 or integrally formed with it. The inverted U-shape of one end of the second conduit 23 prevents dust, rainwater, and other contaminants from entering and clogging it. Alternatively, the first end of the second conduit 23 can also be a straight line extending vertically, with an air-permeable cover installed at the first end to prevent dust, rainwater, and other contaminants from entering and clogging it. The shape of the cover installed at the first end of the second conduit 23 is not specifically limited; various modifications are possible as long as air can enter the first end of the second conduit 23 and dust, rainwater, and other contaminants are prevented from entering and clogging it.

[0068] like Figure 3As shown, when fuel is supplied to the fuel tank 21 by opening the cover of the fuel supply port 211, the air pressure on the upper rear side of the fuel tank 21 increases as the fuel level 28 rises. If air cannot be discharged through the vent 212, fuel cannot enter the space on the upper rear side of the fuel tank 21 because the air pressure on the upper rear side of the fuel tank 21 exceeds a certain pressure, thus failing to fully utilize the space of the fuel tank 21. In this embodiment, since a vent 212 is provided on the upper rear side of the fuel tank 21, and the vent 212 is connected to the fuel supply port 211 via the third pipe 24, the T-shaped tee connector 25, and the first pipe 22, air in the upper rear side of the fuel tank 21 flows from the vent 212 through the third pipe 24, the T-shaped tee connector 25, and the first pipe 22 to the fuel supply port 211. Because the fuel supply port 211 opens when the cover is opened when fuel is supplied to the fuel tank 21, the air flowing into the fuel supply port 211 from the vent 212 is discharged to the outside. As the air in the upper rear part of the fuel tank 21 is discharged to the outside through the vent 212, the third pipe 24, the T-shaped tee connector 25, and the first pipe 22 from the fuel supply port 211, the air pressure in the upper rear part of the fuel tank 21 gradually decreases. Therefore, fuel continues to be injected into the upper rear part of the fuel tank 21, and the fuel level 28 continuously rises. Eventually, the upper rear part of the fuel tank 21 can be filled with fuel supplied from the fuel supply port 211, thereby making full use of the storage space of the fuel tank 21 (see reference). Figure 4 ).

[0069] On the other hand, when the work vehicle 1 is operating, as the engine runs, fuel in the fuel tank 21 is supplied to the engine, causing the fuel level 28 in the fuel tank 21 to continuously drop. This increases the space within the fuel tank 21 where there is no fuel, resulting in a decrease in air pressure within the fuel tank 21, creating a negative pressure. If the air pressure within the fuel tank 21 becomes negative, problems may arise such as the fuel tank 21 being deformed by atmospheric pressure, potentially causing friction and sparks, or the piping being flattened and blocking the fuel supply, leading to a loss of power. In this embodiment, when the pressure within the fuel tank 21 drops to a certain level, the difference between atmospheric pressure and the air pressure within the fuel tank 21 exceeds the opening resistance of the check valve 27, causing the check valve 27 to open. External air enters the interior of the fuel tank 21 through the second piping 23, the T-junction 25, and the third piping 24, changing the air pressure within the fuel tank 21 back to atmospheric pressure. This prevents problems such as the fuel tank 21 deforming due to atmospheric pressure or the piping being flattened and blocking the fuel supply.

[0070] Furthermore, in existing technologies, when a vehicle's fuel tank tilts or overturns due to a road accident or other incident, fuel inside the tank can leak to the outside through vents, piping, etc., posing a hazard and polluting the environment. In this embodiment, as... Figure 2As shown, by installing a check valve 27 between the first and second ends of the second piping 23, even if the fuel tank 21 tilts or overturns due to road conditions or an accident, the fuel in the fuel tank 21 will not leak to the outside through the vent 212, the T-joint 25, and the second piping 23 because the check valve 27 closes the second piping 23. This not only avoids the danger of fuel leakage but also prevents fuel pollution of the environment. Furthermore, fuel leakage to the outside can be prevented simply by installing a check valve 27 between the first and second ends of the second piping 23, resulting in a simple structure, excellent stability, and low cost.

[0071] In addition, when the fuel tank 21 tilts or overturns due to road conditions or an accident, the vent 212 is connected to the fuel supply port 211 via the T-shaped tee connector 25 and the first piping 22. Therefore, the fuel in the fuel tank 21 will flow back to the fuel tank 21 through the vent 212 and the T-shaped tee connector 25 to the first piping 22. Thus, even if the fuel flows to the first piping 22, it will return to the fuel tank 21 and will not leak outside the fuel tank 21. This not only avoids danger and fuel waste, but also prevents fuel leakage from causing environmental pollution.

[0072] As described above, according to this embodiment, the fuel tank system is installed on the working vehicle. The fuel tank system 20 includes: a fuel tank 21, with a vent 212 and a fuel supply port 211 provided on the top surface of the fuel tank 21; a first pipe 22, with a first end connected to the fuel supply port 211 side of the fuel tank and a second end connected to the vent 212 side of the fuel tank; a second pipe 23, with a first end open to the atmosphere and a second end connected to the vent 212; and a check valve 27 installed between the first and second ends of the second pipe 23. The fuel tank system 20 also includes: a third pipe 24, with a first end connected to the vent 212, and the second ends of the first pipe 22, the second pipe 23, and the third pipe 24 connected to each other via a T-shaped tee connector 25. Therefore, when fuel is supplied, fuel enters the fuel tank 21 through the fuel supply port 211. As the fuel level 28 in the fuel tank 21 rises, the air on the upper rear side of the fuel tank 21 is discharged to the outside through the vent 212, the third pipe 24, the T-shaped tee connector 25, the first pipe 22, and the fuel supply port 211, thereby preventing the air pressure in the fuel tank 21 from increasing and thus preventing fuel from being supplied to the fuel tank 21. In addition, when fuel is used, when the pressure in the fuel tank 21 drops to a certain extent, the difference between atmospheric pressure and the air pressure in the fuel tank 21 is greater than the opening resistance of the check valve 27. The check valve 27 opens, and external air enters the interior of the fuel tank 21 through the second pipe 23, the T-shaped tee connector 25, the third pipe 24, and the air pressure in the fuel tank 21 becomes atmospheric pressure, thereby preventing the air pressure in the fuel tank 21 from decreasing and causing deformation of the fuel tank 21.

[0073] Therefore, it can not only prevent fuel leakage from the fuel tank 21 to the outside when the fuel tank 21 is tilted or overturned due to road or accident, but also prevent the fuel tank 21 from becoming negative pressure, thus avoiding problems such as deformation of the fuel tank 21 due to atmospheric pressure, flattening of the piping, and blockage of the fuel line.

[0074] In the above embodiments, the structure of the vent 212 connected to the first pipe 22 and the second pipe 23 via the third pipe 24 and the T-shaped tee connector 25 has been described. However, the present invention is not limited to this and the third pipe 24 and the T-shaped tee connector 25 may also be omitted.

[0075] like Figure 5As shown, both the first piping 22 and the second piping 23 are directly connected to the vent 212. Specifically, the first piping 22 directly connects the fuel supply port 211 and the vent 212; that is, the first end of the first piping 22 is directly connected to the fuel supply port 211, and the second end of the first piping 22 is directly connected to the vent 212. The first end of the second piping 23 is open to the atmosphere, and the second end of the second piping 23 is directly connected to the vent 212. Furthermore, a check valve 27 is installed between the first and second ends of the second piping 23.

[0076] In this embodiment, when fuel is supplied, if the air pressure on the upper rear side of the fuel tank 21 increases and needs to be vented, the air in the rear of the fuel tank 21 flows directly from the vent 212 through the first pipe 22 to the fuel supply port 211. Since the cover of the fuel supply port 211 is opened when fuel is supplied to the fuel tank 21, the air flowing to the fuel supply port 211 is discharged to the outside.

[0077] On the other hand, when the air pressure inside the fuel tank 21 decreases during the operation of the work vehicle 1, when the pressure inside the fuel tank 21 drops to a certain extent, the difference between the atmospheric pressure and the air pressure inside the fuel tank 21 is greater than the opening resistance of the check valve 27. The check valve 27 opens, and the outside air enters the interior of the fuel tank 21 directly through the second pipe 23, the check valve 27, and the vent 212. The air pressure inside the fuel tank 21 becomes atmospheric pressure, thereby avoiding problems such as deformation of the fuel tank 21 due to atmospheric pressure.

[0078] Furthermore, when the fuel tank 21 of the working vehicle 1 tilts or overturns due to road conditions or an accident, the fuel in the fuel tank 21 will not leak to the outside through the vent 212 and the second pipe 23 because the check valve 27 is installed on the second pipe 23 and the check valve 27 is in the closed state.

[0079] In addition, when the fuel tank 21 tilts or overturns due to road conditions or accidents, the fuel in the fuel tank 21 will also flow to the first pipe 22 through the vent 212. Since the first pipe 22 is connected to the fuel supply port 211, the fuel flows to the first pipe 22 to return to the fuel tank 21 without leaking to the outside. This not only avoids the danger of fuel leakage, but also prevents fuel waste.

[0080] As described above, the present invention has been explained in detail, but the above description is illustrative in all respects and the present invention is not limited thereto. Furthermore, the various variations described above can be combined and applied as long as they do not contradict each other. Moreover, it is understood that multiple variations not illustrated can be conceived without departing from the scope of the present invention.

Claims

1. A fuel tank system, wherein, The fuel tank system is installed on the work vehicle. The fuel tank system has: A fuel tank, with a vent and a fuel supply port provided on its top surface; A first piping, the first end of which is connected to the fuel supply port side in the fuel tank, and the second end of which is connected to the vent in the fuel tank; The second piping has a first end open to the atmosphere and a second end connected to the vent. as well as A check valve is installed between the first end and the second end of the second piping.

2. The fuel tank system as claimed in claim 1, wherein, The top surface of the fuel tank includes a first region with the fuel supply port, a second region with the vent, and a third region other than the first and second regions, wherein the height of the first and second regions is higher than the height of the third region.

3. The fuel tank system as claimed in claim 2, wherein, The first region is located on one side of the top surface of the fuel tank, and the second region is located on the other side of the top surface of the fuel tank, separated from the third region.

4. The fuel tank system as described in any one of claims 1 to 3, wherein, The second end of the first pipe and the second end of the second pipe are directly connected to the vent.

5. The fuel tank system as claimed in any one of claims 1 to 3, wherein, The fuel tank system also includes a third piping, the first end of which is connected to the vent. The second ends of the first pipe, the second pipe, and the third pipe are connected to each other in a T-shape.

6. The fuel tank system of claim 5, wherein, The second end of the first pipe, the second end of the second pipe, and the second end of the third pipe are connected via a T-shaped tee connector.

7. The fuel tank system of claim 6, wherein, The T-shaped tee is located between the check valve and the vent.

8. The fuel tank system as claimed in any one of claims 1 to 3, wherein, An air shroud is installed at the first end of the second piping to allow air to enter.

9. The fuel tank system as claimed in any one of claims 1 to 3, wherein, The first end of the second conduit is inverted U-shaped.

10. The fuel tank system of claim 1, wherein, The first end of the first piping is connected to the fuel supply port.

11. A working vehicle, wherein, A fuel tank system having any one of claims 1-10.

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