Fuel tank device

Abstract

To provide a fuel tank device that is able to stably supply fuel to an engine while efficiently supplying the fuel from a sub-tank to a main tank.SOLUTION: A fuel tank device including a plurality of fuel tanks configured to supply fuel to an internal combustion engine of a vehicle, comprises: a main tank having a suction port configured to supply the fuel to the internal combustion engine; a sub-tank configured to supply the fuel to the main tank; and a connection pipe allowing communication between the main tank and the sub-tank and configured to supply the fuel from the sub-tank to the main tank. In the main tank, the connection pipe has a first opening at an end and has a plurality of second openings, smaller than the first opening, on a peripheral surface, and the plurality of second openings are disposed in the vicinity of the suction port.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a fuel tank arrangement. [Background technology]

[0002] Vehicles such as trucks are sometimes provided with a sub-tank in addition to a main tank in order to increase the distance they can travel in one go.

[0003] For example, Patent Document 1 discloses a fuel tank structure for a vehicle that includes a second tank, which is a main tank provided with a fuel suction port and a fuel return port, and a first tank and a third tank, which are sub-tanks respectively connected to the second tank.

[0004] Regarding return fuel returned from an engine (internal combustion engine) to a fuel tank, for example, Patent Document 2 discloses a configuration in which an injector is attached to each cylinder of a diesel engine and a fuel pipe leading to the fuel tank is connected to the injector, and surplus fuel that was not injected is returned to the fuel tank through the fuel pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-180303 A [Patent Document 2] JP 2006-207499 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in a vehicle equipped with a main tank and a sub-tank, such as the technology disclosed in Patent Document 1, the fuel returning from the engine to the fuel tank is returned to the main tank, but this returning fuel may be at a higher temperature than the fuel in the main tank.

[0007] Therefore, when there is only a small amount of fuel in the main tank, the fuel in the main tank may become hot due to the return fuel. Also, supplying hot fuel to the engine may have a negative effect on the injection system. Therefore, it is conceivable to supply fuel from a sub-tank, which is colder than the fuel in the main tank, to the main tank to lower the temperature of the fuel in the main tank.

[0008] In addition, the supply of fuel from the sub-tank to the main tank can be achieved by providing a connecting pipe below each fuel tank, as in the technology disclosed in Patent Document 1, or by using a supply pump to supply fuel from the sub-tank to the main tank.

[0009] In such a case, in order to supply as much of the low-temperature fuel in the sub-tank as possible to the engine, it is desirable to supply fuel from the sub-tank near the intake port in the main tank for supplying fuel to the engine.

[0010] However, there is a risk that air (air bubbles) may become mixed in with the fuel supplied from the sub-tank when it is delivered to the main tank, and if air (air bubbles) become mixed in the fuel, this may hinder a stable supply of fuel to the engine.

[0011] Therefore, an object of the present disclosure is to provide a fuel tank device that can efficiently supply fuel from a sub-tank to a main tank while stabilizing the supply of fuel to an engine. [Means for solving the problem]

[0012] The present disclosure has been made to solve at least some of the problems described above, and can be realized in the following aspects or application examples.

[0013] (1) A fuel tank device according to this application example is a fuel tank device equipped with a plurality of fuel tanks for supplying fuel to an internal combustion engine of a vehicle, comprising: a main tank having an intake port for supplying the fuel to the internal combustion engine; a sub-tank for refilling the fuel to the main tank; and a connecting pipe communicating between the main tank and the sub-tank and equipped with a supply pump for supplying fuel from the sub-tank to the main tank, wherein the connecting pipe has a first opening at an end within the main tank and a plurality of second openings smaller than the first opening on its circumferential surface, the plurality of second openings being arranged in the vicinity of the intake port.

[0014] In this way, by forming multiple second openings on the circumferential surface in addition to the first opening at the end of the connecting pipe on the main tank side, the fuel discharged from the connecting pipe is dispersed when fuel stored in the sub-tank side is replenished to the main tank, and the generation of air bubbles can be suppressed without decreasing the fuel replenishment flow rate. Also, by locating the second opening near the suction port, most of the fuel in the sub-tank, which is lower in temperature than the return fuel, is sucked in through the suction port. In this way, low-temperature fuel with reduced air bubble generation can be efficiently supplied to the engine, stabilizing the fuel supply to the engine. [Brief description of the drawings]

[0015] [Figure 1] 1 is a plan view showing an external appearance of a fuel tank device according to an embodiment of the present invention; [Diagram 2] 1 is a schematic diagram showing a fuel tank device according to an embodiment of the present invention; [Diagram 3] 4 is an enlarged side view showing a first opening and a second opening of the connecting pipe. FIG. [Figure 4] FIG. 4 is an enlarged bottom view of FIG. 3 as viewed from the bottom. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the up-down direction refers to the height direction (vertical direction) of the vehicle, and the front-rear direction refers to the traveling direction of the vehicle. In addition, hereinafter, the end portion includes not only the tip surface but also a predetermined range from the tip surface.

[0017] Fig. 1 is a plan view showing the appearance of a fuel tank device 1 for a vehicle in one embodiment of the present invention, and Fig. 2 is a schematic configuration diagram showing a side view of the fuel tank device 1. The vehicle on which the fuel tank device 1 for a vehicle of this embodiment is mounted is a cargo vehicle such as a truck. As shown in Figs. 1 and 2, the fuel tank device 1 includes a main tank 11, a sub-tank 12, and a connecting pipe 13 that communicates between the main tank 11 and the sub-tank 12 and is equipped with a supply pump 14.

[0018] The main tank 11 and the sub tank 12 are roughly rectangular parallelepiped containers of roughly the same size, and are provided side by side in the front-to-rear direction on the left side rail 2 of the vehicle. The main tank 11 and the sub tank 12 each have filler ports 21a, 21b formed on the top surface, near the outer side in the vehicle width direction, for injecting fuel into the tank from the outside. Each filler port 21a, 21b is cylindrical and protrudes from the top surface of the tank, and has a lid at its tip.

[0019] A supply pipe 22 and a return pipe 23 are connected to the center of the top surface of the main tank 11. The supply pipe 22 and the return pipe 23 are connected to an engine (not shown).

[0020] The supply pipe 22 is a pipe for supplying fuel from the main tank 11 to the engine. As shown in Fig. 2, the supply pipe 22 penetrates the upper surface of the main tank 11 and extends to the vicinity of the bottom of the main tank 11. The supply pipe 22 has an intake port 22a at its tip for sucking in fuel. A filter 25 is disposed around the intake port 22a so as to surround the intake port 22a. The filter 25 in this embodiment has a substantially rectangular parallelepiped shape, a mesh-shaped bottom, and a function of preventing foreign matter from entering the intake port 22a.

[0021] The return pipe 23 is a pipe for returning surplus fuel from the engine to the main tank 11. As shown in Fig. 2, the return pipe 23 penetrates the upper surface of the main tank 11 and protrudes slightly inward from the upper surface.

[0022] Furthermore, the main tank 11 is provided with a level sensor 24 that is movable up and down along the inner surface of the side wall. The level sensor 24 is, for example, a float, and has a function of detecting the liquid level of the fuel inside the main tank 11 and generating information on the fuel level FL.

[0023] One end of the connecting pipe 13 is connected to the supply pump 14 provided in the subtank 12, and the other end is disposed near the suction port 22a in the main tank 11. Specifically, the connecting pipe 13 extends upward from the supply pump 14, penetrates the upper surface of the subtank 12, and extends toward the main tank 11 at the front of the vehicle. The connecting pipe 13 then penetrates the upper surface of the main tank 11, extends near the bottom of the main tank 11, and extends along the bottom surface to a position near the suction port 22a of the supply pipe 22. In this way, the connecting pipe 13 is a pipe that communicates between the inside of the main tank 11 and the inside of the subtank 12, and forms a communication passage that allows the fuel stored in the subtank 12 to be replenished to the main tank 11.

[0024] FIG. 3 is an enlarged side view of an end portion of the connecting pipe 13 disposed in the main tank 11, and FIG. 4 is an enlarged bottom view of FIG. 3 as viewed from the bottom.

[0025] 3 and 4, a first opening 13a is formed in the tip surface of the connecting pipe 13 disposed inside the main tank 11. The connecting pipe 13 is a circular pipe, and the first opening 13a is a circular hole.

[0026] Further, near the first opening 13a of the connecting pipe 13, on the suction port 22a side of the peripheral surface of the connecting pipe 13, a plurality of second openings 13b (five in this embodiment) are formed at equal intervals in the longitudinal direction of the connecting pipe 13. Each of the second openings 13b is a circular hole, and the hole diameter thereof is smaller than the hole diameter of the first opening 13a.

[0027] The supply pump 14 is an electric pump provided in the sub tank 12. The supply pump 14 pumps up the fuel stored in the sub tank 12 and supplies the pumped up fuel into the main tank 11 via the connecting pipe 13. The supply pump 14 in this embodiment also has a function of adjusting the flow rate of the fuel supplied into the main tank 11.

[0028] The vehicle is also equipped with a VCU 31 (Vehicle Control Unit, control section). The VCU 31 is a computer equipped with a central processing unit (CPU), a main memory device (ROM, RAM, etc.) for storing control programs, control maps, etc., an input / output device, a timer counter, etc. The VCU 31 is communicatively connected to various devices and other control units mounted on the vehicle via a control area network (CAN) that is an in-vehicle communication network. The VCU 31 of this embodiment is communicatively connected to the supply pump 14 and the level sensor 24.

[0029] In detail, the VCU 31 has a function of acquiring information on the liquid level of the fuel stored in the main tank 11 from the level sensor 24 at a predetermined time period as a fuel level FL, and monitoring the fuel in the main tank 11. In addition, the VCU 31 compares the acquired fuel level FL with a first fuel level FL1 stored in advance in a main storage device in the VCU 31 (fuel level determination), and when the fuel level FL is lower than the first fuel level FL1, determines that refueling from the sub-tank 12 is necessary. The first fuel level FL1 is set, for example, at a position higher than the suction port 22a of the supply pipe 22 and the end of the connection pipe 13 on the main tank 11 side.

[0030] When the VCU 31 determines that refueling from the sub-tank 12 is necessary, it controls the drive of the supply pump 14 to supply the fuel stored in the sub-tank 12 to the main tank 11 via the connecting pipe 13 .

[0031] In this way, the VCU 31 determines whether or not it is necessary to replenish fuel to the main tank 11 based on the liquid level information from the level sensor 24, and if it determines that replenishment is necessary, it operates the supply pump 14 to supply the fuel in the sub-tank 12 to the main tank 11.

[0032] Next, the flow of fuel when refueling from the sub-tank 12 to the main tank 11 will be described.

[0033] When the supply pump 14 is operated by the VCU 31, the fuel in the sub-tank 12 is sucked up and transferred to the main tank through the connecting pipe 13, as shown by the white arrow in FIG.

[0034] As shown in detail in FIG. 3 and FIG. 4, the end of the connecting pipe 13 on the main tank 11 side is provided with a plurality of second openings 13b on the circumferential surface in addition to the first opening 13a, so that the fuel from the sub-tank 12 is dispersed to each of the openings 13a, 13b and discharged into the main tank 11. By dispersing the fuel in this manner, the flow rate of the fuel discharged from each of the openings 13a, 13b is smaller than when the fuel is discharged only from the first opening 13a, and the generation of air bubbles is suppressed. On the other hand, the flow rate supplied into the main tank 11 does not change and depends on the amount of fuel pumped up by the supply pump 14. That is, in the fuel tank device 1 of this embodiment, the fuel supplied from the sub-tank 12 to the main tank 11 is supplied into the main tank 11 slowly relative to the amount of fuel pumped up from the sub-tank 12.

[0035] Furthermore, the end of the connecting pipe 13 on the main tank 11 side is disposed near the suction port 22a of the supply pipe 22, and in particular the second opening 13b opens toward the suction port 22a side. Therefore, most of the fuel from the sub-tank 12, which is at a lower temperature than the return fuel, is directly sucked into the suction port 22a.

[0036] As described above, according to the vehicle fuel tank device 1 of this embodiment, in addition to the first opening 13a, a plurality of second openings 13b are formed at the end of the connecting pipe 13 on the main tank 11 side. As a result, when fuel stored on the sub-tank 12 side is replenished to the main tank 11, the fuel discharged from the connecting pipe 13 is dispersed, and the generation of air bubbles can be suppressed without decreasing the fuel replenishment flow rate. In addition, since the second opening 13b is disposed near the suction port 22a of the supply pipe 22, most of the fuel in the sub-tank 12, which is at a lower temperature than the return fuel, is sucked in from the suction port 22a. In this way, low-temperature fuel with the generation of air bubbles suppressed can be efficiently supplied to the engine, thereby stabilizing the fuel supply to the engine.

[0037] This concludes the description of the embodiment of the vehicle fuel tank device 1 according to the present invention, but the aspects of the present invention are not limited to this embodiment.

[0038] 2 to 4, five second openings 13b are formed, but as long as the generation of bubbles due to the fuel supplied from the second openings can be suppressed, the number of second openings is not limited to five and may be two or more. The arrangement of the second openings is also not limited to the arrangement in the above embodiment, and for example, a plurality of second openings aligned in the longitudinal direction may be formed in multiple rows.

[0039] In the above embodiment, the bottom surface of the filter 25 is mesh-shaped, but other filter structures may be used as long as they can prevent foreign matter from entering the suction port. For example, the filter may have filter paper inside the case.

[0040] In the above embodiment, the first opening 13a is formed in the tip surface of the connecting pipe 13, but it is also possible to form only the multiple second openings 13b without forming the first opening 13a. [Explanation of symbols]

[0041] 1 Fuel tank device 11 Main Tank 12 Subtank 13 Connecting pipe 13a 1st opening 13b 2nd opening 14 Supply pump 21 Inlet 22 Supply pipe 22a Intake port 23 Return pipe 24 Level Sensor 25 Filters 31 VCU (control unit)

Claims

[Claim 1] A fuel tank device including a plurality of fuel tanks for supplying fuel to an internal combustion engine of a vehicle, a main tank having a suction port for supplying the fuel to the internal combustion engine; a sub-tank for replenishing the fuel to the main tank; a connecting pipe that communicates the main tank and the sub tank and has a supply pump that supplies fuel from the sub tank to the main tank, a connecting pipe having a first opening at an end thereof within the main tank and a plurality of second openings smaller than the first opening on a peripheral surface thereof, the plurality of second openings being disposed in the vicinity of the suction port.

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