Work vehicles

Abstract

The present invention provides a work vehicle, which has fuel tanks arranged on the left and right sides of a traveling vehicle body, wherein a fuel supply pipe is connected to one fuel tank, and a fuel tank structure that can maintain left-right balance and has little air entrainment can be obtained. The work vehicle has: a first fuel tank; and a second fuel tank, which has a fuel supply port for supplying fuel to the engine, the first fuel tank and the second fuel tank are connected by a connecting pipe, a branch pipe portion branched from a midway portion of the connecting pipe is connected to the second fuel tank, a check valve is provided at a portion of the connecting pipe between the midway portion and the second fuel tank, and a connection portion of the branch pipe portion connected to the second fuel tank is arranged at a position above a connection portion of the connecting pipe connected to the second fuel tank.

Description

Technical Field

[0001] The invention relates to working vehicles such as agricultural tractors, and in particular to a fuel tank structure. Background Art

[0002] For an agricultural tractor as an example of a working vehicle, there is a structure in which fuel tanks are arranged on the left and right sides of a transmission case in order to increase the fuel tank capacity, a connecting pipe is provided between the left and right fuel tanks to allow fuel to flow, and the connecting pipe is provided at a position lower than the bottom of the fuel tank and is connected to a fuel supply pipe that supplies fuel to the engine (Patent Document 1).

[0003] Furthermore, a structure in which a check valve is provided in a connecting pipe to prevent the backflow deviation of the fuel is known (Patent Document 2).

[0004] Patent Document 1: Japanese Patent No. 5726540

[0005] Patent Document 2: Japanese Patent Publication No. 2007-297006

[0006] However, in the fuel tank structure of Patent Document 1, the position of the fuel supply port on the connecting pipe is improved so that the fuel that is offset to the side of the fuel tank with a larger capacity can easily reach the fuel supply port. However, since the fuel supply port is provided on the connecting pipe connecting the left and right sides, when the traveling vehicle body tilts left or right, the liquid level in the connecting pipe is more likely to change than the liquid level in the fuel tank on the tilted lower side, and air may be drawn in.

[0007] Furthermore, in the structure of Patent Document 2, since a check valve is provided to prevent the backflow of fuel, the fuel supply port is not provided in the connecting pipe, but in one of the left and right fuel tanks. This method is effective, but when the amount of fuel stored is large, the left-right balance may be impaired. Summary of the invention

[0008] The present invention has been made in view of the above-mentioned situation, and has a structure in which a fuel supply pipe is connected to one fuel tank, and a fuel tank structure with little air entrainment can be obtained while maintaining left-right balance.

[0009] The present invention adopts the following technical means to solve the above-mentioned problems.

[0010] The invention described in technical solution 1 is a working vehicle, which is equipped with an engine E on a traveling vehicle body 1, and the working vehicle has: a first fuel tank 20L; and a second fuel tank 20R, which has a fuel supply port 30a for supplying fuel to the engine E, the first fuel tank 20L and the second fuel tank 20R are connected by a connecting pipe 31, and a branch pipe portion 31d branched from the middle part of the connecting pipe 31 is connected to the second fuel tank 20R, and the connecting pipe 31 is connected to the second fuel tank 20R at the middle part of the connecting pipe 31. A check valve 32 is provided in the portion between the fuel tanks 20R. The check valve 32 allows the fuel to flow from the first fuel tank 20L side to the second fuel tank 20R side, but prevents the fuel from flowing back from the second fuel tank 20R side to the first fuel tank 20L side. The working vehicle is constructed such that the connection portion 31C of the branch pipe portion 31d connected to the second fuel tank 20R is arranged above the connection portion 31B of the connecting pipe 31 connected to the second fuel tank 20R.

[0011] The invention described in claim 2 is the work vehicle described in claim 1 , wherein the first fuel tank 20L and the second fuel tank 20R are formed in a stepped shape to constitute upper and lower steps 38L, 38R for the upper and lower cabs 16 .

[0012] The invention described in claim 3 is the working vehicle described in claim 1 or 2, wherein the tank capacity of the first fuel tank 20L is configured to be smaller than the capacity of the second fuel tank 20R, and the working vehicle is configured such that a urea tank 23 is arranged in front of the first fuel tank 20L.

[0013] The invention described in claim 4 is the working vehicle described in any one of claims 1 to 3, wherein the working vehicle is configured such that a support plate 24 supporting a lower portion of a urea tank 23 is connected to a second support plate 22 of the first fuel tank 20L.

[0014] According to the invention described in technical solution 1, by providing a check valve 32, fuel can be allowed to remain on the side of the second fuel tank 20R having a fuel supply pipe 30 for supplying fuel to the engine E. Furthermore, when the amount of fuel in the second fuel tank 20R is large, the fuel is transported to the side of the first fuel tank 20L via the branch pipe portion 31d, so that the fuel is not excessively stored on the side of the second fuel tank 20R, and the left and right balance can be maintained. In addition, air entrainment can also be suppressed.

[0015] According to the invention described in claim 2, in addition to the effects described in claim 1, the first fuel tank 20L and the second fuel tank 20R can be formed as the upper and lower steps 38L and 38R.

[0016] According to the invention described in claim 3, in addition to the effects described in claim 1 or claim 2, the left-right balance of the vehicle body can be maintained.

[0017] According to the invention described in claim 4, in addition to the effects of any one of claims 1 to 3, the load of the urea tank and the first fuel tank 20L can be shared. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a side view of the tractor.

[0019] Figure 2 This is a three-dimensional diagram of the main parts viewed from above.

[0020] Figure 3 This is a perspective view of the main parts viewed from below.

[0021] Figure 4 It is the main view of the main part.

[0022] Figure 5 It is an enlarged front view of the main part.

[0023] Figure 6 It is a three-dimensional diagram of the step portion.

[0024] Description of symbols

[0025] 1: traveling vehicle body; 3: transmission case; 20L: first fuel tank; 20R: second fuel tank; 20a: fuel supply port; 30a: fuel supply port; 31: connecting pipe; 31d: branch pipe portion; 31A: connecting portion; 31B: connecting portion; 31C: connecting portion; 32: check valve; E: engine. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

[0027] Figure 1 1 is a diagram showing a tractor, in which a diesel engine E is mounted inside an engine hood 2 at the front of a traveling vehicle body 1, and the rotational power of the engine E is transmitted to a transmission device inside a transmission case 3, and the rotational power reduced by the transmission device is transmitted to the front wheels 4 and the rear wheels 5. A steering wheel 6 for steering the front wheels 4, 4 is installed behind the engine E, and a driver's seat 7 is provided behind the steering wheel 6. A hydraulic cylinder housing 8 is provided at the rear upper part of the transmission case 3, and a lifting arm 9 constituting a part of a hydraulic lifting mechanism is rotatably installed on the left and right sides of the hydraulic cylinder housing 8. The lifting arm 9 moves up and down by the telescopic action of a lifting hydraulic cylinder 10. A three-point linkage mechanism consisting of an upper link 11 and left and right lower links 12 is provided at the rear of the vehicle body, and a rotating working machine R is installed on the linkage mechanism, and the lower link 12 is connected to the lifting arm 9 via a lifting rod 13, so that the working machine R can be raised and lowered.

[0028] The steering wheel 6, the driver's seat 7, and the like are covered by a cockpit 16. The cockpit 16 is fixed to the machine body via an elastic member such as a vibration-proof rubber, so that vibration of the machine body is difficult to be transmitted to the cockpit.

[0029] In addition, the cockpit 16 is formed into an integrated frame structure by a floor 17, front pillars 16a erected at the left and right front parts of the floor 17, rear pillars 16b erected at the middle parts of the left and right fenders 18, and an upper frame 16c connecting the upper ends of these pillars to each other, and the frame structure is covered by a top 16d.

[0030] A fuel tank 20 formed of a resin material is disposed on the left and right sides of the transmission case 3. Figure 2 to Figure 6 As shown, the fuel tank 20 is made of a resin material and is produced by blow molding. The fuel tank 20 is a structure arranged on the left and right sides of the transmission case 3. The tank capacity of the first fuel tank 20L on one side is made smaller than the capacity of the second fuel tank 20R on the other side. Among them, the first fuel tank 20L is formed into a main body 20La close to the transmission case 3 and an extension 20Lb located on the outside. The bottom of the main body 20La is supported by a first support plate 21 connected to the transmission case 3, and the extension 20Lb is supported by a second support plate 22 fixedly connected to the first support plate 21.

[0031] In addition, a urea tank 23 of a urea SCR system is arranged just in front of the first fuel tank 20L. A support plate 24 supporting the lower portion of the urea tank 23 is supported by the transmission case 3, and the support plate 24 of the urea tank is connected to the second support plate 22 of the first fuel tank 20L to share the load of the fuel tank 20L.

[0032] Regarding the support structure of the first fuel tank 20L, the extension portion 20Lb is supported by the belt-shaped plate 25L. The cab support bracket 39L and the auxiliary bracket 40L are provided in a state of extending to the left and right from the transmission case 3, and the belt-shaped plate 25L is suspended and supported by the distal ends of these brackets.

[0033] Furthermore, since the first fuel tank 20L is formed into the main body 20La and the extension 20Lb by blow molding of resin, a fuel supply port 20a as a fuel supply portion is formed in the extension 20Lb, and a fuel supply cap 27 is detachably mounted.

[0034] Next, the second fuel tank 20R on the other side is formed into a main body 20Ra and an extension 20Rb, but the support plate 28 for the second fuel tank 20R supporting the bottom of the tank is formed as a plate frame formed by connecting the front and rear door-shaped steel materials, and the support plate 28 is fixed to the side wall or the bottom wall of the transmission case 3 by means of brackets 29a and 29b, thereby supporting the second fuel tank 20R. On the second fuel tank 20R side, a fuel supply port 30a is formed at the lower front position, and one end of a fuel supply pipe 30 is connected to the fuel supply port 30a, and the other end of the fuel supply pipe 30 for supplying fuel to the engine E via a fuel pump not shown is connected to the engine E.

[0035] In the arrangement relationship between the first fuel tank 20L and the second fuel tank 20R, the front end of each tank is in a relationship that the second fuel tank 20R side with a larger capacity is located in the front, and the first fuel tank 20L side with a smaller capacity is located in the rear, and is also located in the rear in the arrangement relationship with the urea tank 23. On the other hand, the rear end of each tank is in a relationship that the rear end of the first fuel tank 20L is located in front of the rear end of the second fuel tank 20R.

[0036] Furthermore, the first fuel tank 20L and the second fuel tank 20R are attached to the transmission case 3 so that their bottom surfaces have different heights, and the bottom surface of the first fuel tank 20L is provided to be higher than the bottom surface of the second fuel tank 20R.

[0037] As described above, since the fuel supply port 20a is provided on the first fuel tank 20L side, the first fuel tank 20L and the second fuel tank 20R are connected together by the resin connecting pipe 31. That is, the connecting pipe 31, one end of which is connected to the inner side of the front lower portion of the first fuel tank 20L, is in a straight line with substantially the same diameter, but a first curved portion 31a, a second curved portion 31b, and a crank-shaped third curved portion 31c for forming a gentle inclination are formed in the middle. The other end of the connecting pipe 31 is provided in a manner connected to the inner side of the front lower portion of the second fuel tank 20R.

[0038] Furthermore, a branch pipe portion 31d is provided, which branches from a portion close to the first fuel tank 20L near the third bent portion 31c and is connected to the front middle portion of the second fuel tank 20R. As described above, the first fuel tank 20L and the second fuel tank 20R are configured to have different bottom surfaces from the ground, and the connection portion of the connecting pipe 31 is arranged along the bottom surfaces. Figure 5As shown, the connection portion 31A between the first fuel tank 20L and the connecting pipe 31 is set to be higher by a height H1 than the connection portion 31B between the second fuel tank 20R and the connecting pipe 31, and the connection portion 31C between the second fuel tank 20R and the branch pipe portion 31d is set to be higher by a height H2 than the connection portion 31B between the second fuel tank 20R and the connecting pipe 31. In addition, the height H2 is set to be larger than the height H1.

[0039] In addition, the fuel supply port 30a of the second fuel tank 20R, which is connected to the fuel supply pipe 30 for supplying fuel to the engine E, is configured to be connected to the lowest position of the second fuel tank 20R.

[0040] Next, between the third curved portion 31c of the connecting pipe 31 and the second fuel tank 20R, in other words, on the side closer to the second fuel tank 20R than the midway portion between the connecting pipe 31 and the branch pipe portion 31d, a check valve 32 is provided. The check valve 32 is a thin-film valve body such as that shown in FIG. 8 of Patent Document 2, and is configured to allow the fuel to flow from the first fuel tank 20L to the second fuel tank 20R side, but to prevent the fuel from flowing in the opposite direction from the second fuel tank 20R to the first fuel tank 20L.

[0041] When the fuel supply cap 27 of the fuel tank 20 constructed as described above is removed and fuel (light oil) is injected from the fuel supply hole 20a, the fuel first enters the first fuel tank 20L and also enters the second fuel tank 20R through the connecting pipe 31 and the check valve 32 in the connecting pipe 31. When the amount of fuel gradually increases, the fuel flows into the second fuel tank 20R from the connecting portion 31B of the connecting pipe 31 and the connecting portion 31C of the branch pipe portion 31d, and the fuel amount in the second fuel tank 20R also increases.

[0042] Furthermore, the fuel is consumed by the operation of the engine E, but when the vehicle body 1 tilts left or right during traveling, the fuel can be kept balanced while traveling back and forth between the first fuel tank 20L and the second fuel tank 20R through the connecting pipe 31. Specifically, when the fuel amount exceeds the connection portion 31C of the branch pipe portion 31d of the second fuel tank 20R, when the vehicle body 1 tilts and the second fuel tank 20R side rises, the fuel can flow back to the first fuel tank 20L side through the branch pipe portion 31d, but the backflow of the fuel from the connection portion 31B of the second fuel tank 20R to the first fuel tank 20L is blocked by the presence of the check valve 32. In addition, when the fuel amount is below the connection portion 31C of the branch pipe portion 31d of the second fuel tank 20R in the horizontal position, even if the second fuel tank 20R side rises, the fuel cannot exceed the connection portion 31C and therefore cannot flow back to the first fuel tank 20L side.

[0043] In addition, when the first fuel tank 20L side becomes higher, even a small amount of fuel can flow out from the connection portion 31B through the check valve 32 of the communication pipe 31 and flow into the fuel tank 20L. In addition, since the connection portion 31B of the second fuel tank 20R is lower than the connection portion 31A of the first fuel tank 20L by the height H1, a small amount of remaining fuel can all move to the second fuel tank 20R side.

[0044] The fuel supplied to the engine E is supplied to the engine E from a fuel supply pipe 30 connected to the second fuel tank 20R, but the fuel supply pipe 30 is configured to supply fuel from a fuel supply port 30a formed as close to the bottom as possible of the second fuel tank 20R, thereby reducing the remaining fuel amount.

[0045] The first fuel tank 20L and the second fuel tank 20R are connected at their upper parts by a ventilation connecting pipe 33, and a narrow-diameter ventilation pipe 34 whose upper end is open to the atmosphere is provided in one fuel tank (in the example, the second fuel tank 20R with a larger capacity) or both fuel tanks.

[0046] A fuel sensor 35 is disposed on the second fuel tank 20R side connected to the fuel supply pipe 30. The fuel sensor 35 may be any known type, such as a stroke sensor, and may be located at a location where the liquid level changes relatively little even when the vehicle body 1 is tilted.

[0047] The extensions 20Lb and 20Rb of the first fuel tank 20L and the second fuel tank 20R are formed in a step shape and constitute the support parts of the upper and lower steps 38L and 38R. That is, as described above, the cockpit support brackets 39L and 39R and the auxiliary brackets 40L and 40R are arranged to extend to the left and right from the transmission case 3, and the upper and lower steps 38L and 38R composed of two stages made of iron plates are supported on the end sides of these brackets. Since the lower steps 38L and 38R are arranged, the extensions 20Lb and 20Rb of the first fuel tank 20L and the second fuel tank 20R are formed with step support parts. In addition, the cockpit support brackets 39L and 39R and the auxiliary brackets 40L and 40R are also used as the support structure of the fuel tanks 20L and 20R.

[0048] In the figure, reference numeral 41 denotes a fuel filter present in the middle of the fuel supply pipe 30, reference numeral 42 denotes an SCR system, and reference numeral 43 denotes a tool box.

Claims

1. A working vehicle, wherein: An engine (E) is mounted on a traveling vehicle body (1). The working vehicle has: A first fuel tank (20L); and a second fuel tank (20R) having a fuel supply port (30a) for supplying fuel to the engine (E), A fuel supply port (20a) is provided in the first fuel tank (20L), and the bottom surface of the first fuel tank (20L) is higher than the bottom surface of the second fuel tank (20R). A first fuel tank (20L) and a second fuel tank (20R) are connected via a connecting pipe (31), and a connecting portion (31A) between the first fuel tank (20L) and the connecting pipe (31) is set higher than a connecting portion (31B) between the second fuel tank (20R) and the connecting pipe (31) by a first height (H1). A branch pipe portion (31d) branched from the middle portion of the connecting pipe (31) is connected to the second fuel tank (20R). A check valve (32) is provided at a portion of the connecting pipe (31) between the midway portion and the second fuel tank (20R), the check valve (32) allowing fuel to flow from the first fuel tank (20L) side to the second fuel tank (20R) side but preventing fuel from flowing back from the second fuel tank (20R) side to the first fuel tank (20L) side. The working vehicle is configured such that a connection portion (31C) of the branch pipe portion (31d) connected to the second fuel tank (20R) is arranged at a position higher than a connection portion (31B) of the connecting pipe (31) connected to the second fuel tank (20R) by a second height (H2), The second height (H2) is greater than the first height (H1).

2. The work vehicle according to claim 1, wherein: The first fuel tank (20L) and the second fuel tank (20R) are formed in a step shape to form upper and lower steps (38L, 38R) for the upper and lower cockpits (16).

3. The working vehicle according to claim 1 or 2, wherein: The tank capacity of the first fuel tank (20L) is configured to be smaller than the capacity of the second fuel tank (20R), and the working vehicle is configured such that a urea tank (23) is arranged in front of the first fuel tank (20L).

4. The working vehicle according to claim 1 or 2, wherein: The working vehicle is configured such that a support plate (24) supporting a lower portion of a urea tank (23) is connected to a second support plate (22) of the first fuel tank (20L).

5. The work vehicle according to claim 3, wherein: The working vehicle is configured such that a support plate (24) supporting a lower portion of a urea tank (23) is connected to a second support plate (22) of the first fuel tank (20L).

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