Fuel supply system and fuel control method for internal combustion engine

Abstract

A fuel supply system (100) and a fuel control method for a vehicle are provided. The fuel supply system comprises: a fuel injection unit (1) configured to inject fuel into an internal combustion engine; a main fuel storage unit (4) configured to store unfiltered fuel; an auxiliary fuel storage unit (3) having a smaller volume than the main fuel storage unit (4) and configured to store filtered fuel; a first fuel pump (7); and a second fuel pump (12); the first fuel pump (7) is connected at its positive pressure side to the fuel injection unit (1), at its negative pressure side to the auxiliary fuel storage unit (3) via a first fuel path (A) without the second fuel pump (12) and a third fuel path (C) with the second fuel pump (12), and via a second fuel path (B); the fuel supply system (100) is configured to be controlled to selectively operate in a first operating mode in which the first fuel pump (7) is open and the second fuel pump (12) is closed, a second operating mode in which the first fuel pump (7) is closed, and a third operating mode in which the second fuel pump (12) is closed. In a second mode of operation, the first fuel pump (7) is open and the second fuel pump (12) is open to rotate in a forward direction; in a third mode of operation, the first fuel pump (7) is open and the second fuel pump (12) is open to rotate in a reverse direction.

Description

Technical Field

[0001] The present invention relates to a fuel supply system and a fuel control method for an internal combustion engine. Background Art

[0002] An internal combustion engine is an engine that uses the Otto cycle as a basic principle and utilizes various fuels, such as a gasoline engine, a diesel engine, etc. The fuel supply system of the internal combustion engine generally includes a fuel storage unit, a fuel filter unit, a fuel pump unit, a fuel injection unit, etc. By using the fuel pump unit, the fuel stored in the fuel storage unit is filtered by the fuel filter unit and then injected into the combustion chamber via the fuel injection unit for combustion.

[0003] There are some problems with the existing fuel supply system:

[0004] 1) After the vehicle has been running for a period of time, the resistance of the fuel filter unit increases, and the fuel pump unit has difficulty pumping fuel;

[0005] 2) Some fuel storage units have a large volume. When the remaining fuel is small, the fuel line arranged in the fuel storage unit cannot draw fuel during uphill or downhill, resulting in insufficient power of the vehicle or even stopping due to lack of fuel.

[0006] 3) Fuel pumps are susceptible to impurities and moisture / water in the fuel, causing premature wear and rust.

[0007] To this end, it is desired to optimize the fuel supply system to overcome the above-mentioned disadvantages. Summary of the invention

[0008] An object of the present disclosure is to provide a fuel supply system that reduces resistance of a fuel path, ensures stable operation even during uphill or downhill running, and minimizes impurities and moisture in the fuel.

[0009] In one aspect, a fuel supply system is provided. The fuel supply system comprises:

[0010] a fuel injection unit configured to inject fuel into the internal combustion engine;

[0011] a main fuel storage unit configured to store unfiltered fuel;

[0012] an auxiliary fuel storage unit having a smaller volume than the main fuel storage unit and configured to store filtered fuel;

[0013] a first fuel pump; and

[0014] a second fuel pump;

[0015] a first fuel pump connected at a positive-pressure side thereof to the fuel injection unit and at a negative-pressure side thereof to the auxiliary fuel storage unit via a first fuel path without a second fuel pump and a third fuel path with a second fuel pump, and to the auxiliary fuel storage unit via a second fuel path;

[0016] The fuel supply system is configured to be controlled to selectively operate in a first operating mode, a second operating mode, and a third operating mode. In the first operating mode, the first fuel pump is turned on and the second fuel pump is turned off; in the second operating mode, the first fuel pump is turned on and the second fuel pump is turned on to rotate in a forward direction; in the third operating mode, the first fuel pump is turned on and the second fuel pump is turned on to rotate in a reverse direction.

[0017] Preferably, the fuel supply system further comprises an electronic control unit configured to control the fuel supply system to selectively operate in the first operation mode, the second operation mode and the third operation mode.

[0018] Preferably:

[0019] The electronic control unit is configured to control the fuel supply system to operate in a first operation mode when the vehicle is operating normally, wherein the first fuel pump pumps fuel to the fuel injection unit via the first fuel path and the second fuel path; in the first fuel path, filtered fuel flows from the auxiliary fuel storage unit to the fuel injection unit through the first fuel pump; in the second fuel path, fuel flows from the main fuel storage unit to the fuel injection unit;

[0020] the electronic control unit being configured to control the fuel supply system to operate in a second operation mode when the vehicle is started, the resistance of the fuel supply system is equal to or greater than a first threshold value, and / or the vehicle is on an uphill or downhill slope, wherein the first fuel pump operates as in the first operation mode, the second fuel pump rotates in a forward direction to supply fuel to the fuel injection unit via a third fuel path, in which filtered fuel flows from the auxiliary fuel storage unit through the second fuel pump and the first fuel pump to the fuel injection unit; and

[0021] The electronic control unit is configured to control the fuel supply system to operate in a third operation mode when the fuel level of the auxiliary fuel storage unit is below a second threshold value, wherein the first fuel pump operates as in the first operation mode and the second fuel pump rotates in a reverse direction to supply fuel from the main fuel storage unit to the auxiliary fuel storage unit via a fourth fuel path.

[0022] Preferably, the fuel supply system further includes a first fuel sensor disposed in the auxiliary fuel storage unit and configured to sense a fuel level of the auxiliary fuel storage unit.

[0023] Preferably, the fuel supply system further comprises a second fuel sensor disposed in the main fuel storage unit and configured to sense a fuel level of the main fuel storage unit.

[0024] Preferably, the fuel supply system also includes a first fuel filter and a second fuel filter, both of which are arranged downstream of the main fuel storage unit, wherein, in the second fuel path, unfiltered fuel flows from the main fuel storage unit to the fuel injection unit through the first fuel filter, the second fuel filter and the first fuel pump; and in the fourth fuel path, unfiltered fuel flows from the main fuel storage unit to the auxiliary fuel storage unit through the first fuel filter, the second fuel filter and the second fuel pump.

[0025] Preferably, the fuel supply system further comprises:

[0026] a first check valve disposed between the first fuel pump and the auxiliary fuel storage unit and configured to prevent fuel from flowing back to the auxiliary fuel storage unit;

[0027] a second check valve disposed between the first fuel pump and the second fuel pump and configured to prevent fuel from flowing back to the auxiliary fuel storage unit; and

[0028] The third check valve is disposed between the main fuel storage unit and the second fuel pump and is configured to prevent the fuel from flowing back to the main fuel storage unit.

[0029] Preferably, the fuel supply system further includes a pressure balancing line disposed between the main fuel storage unit and the auxiliary fuel storage unit and configured to discharge excess gas or fuel from the auxiliary fuel storage unit into the main fuel storage unit.

[0030] Preferably, the fuel supply system further includes a fourth check valve disposed in the pressure balance line and configured to prevent gas or fuel from flowing back from the primary fuel storage unit to the auxiliary fuel storage unit.

[0031] Preferably, the first fuel filter is configured to filter particles from the fuel, and the second fuel filter is configured to filter both particles and water from the fuel.

[0032] Preferably, the fuel supply system also includes a fuel return control valve connected to the fuel injection unit via a fuel return line, and distributes the fuel of the fuel return line via first, second and third return pipes as needed to heat the interior of the auxiliary fuel storage unit, the inlet of the second fuel filter and the main fuel storage unit, respectively.

[0033] In another aspect, a fuel control method using the above fuel supply system is provided, comprising:

[0034] When the vehicle is operating normally, the fuel supply system is controlled to operate in a first operation mode, wherein the first fuel pump pumps fuel to the fuel injection unit via the first fuel path and the second fuel path; in the first fuel path, filtered fuel flows from the auxiliary fuel storage unit to the fuel injection unit through the first fuel pump; in the second fuel path, fuel flows from the main fuel storage unit to the fuel injection unit;

[0035] When the vehicle is started, the resistance of the fuel supply system is equal to or greater than the first threshold value, and / or the vehicle is on an uphill or downhill slope, controlling the fuel supply system to operate in a second operation mode, wherein the first fuel pump operates as in the first operation mode, the second fuel pump rotates in a forward direction to supply fuel to the fuel injection unit via a third fuel path, in which filtered fuel flows from the auxiliary fuel storage unit through the second fuel pump and the first fuel pump to the fuel injection unit; and

[0036] When the fuel level of the auxiliary fuel storage unit is below a second threshold, the fuel supply system is controlled to operate in a third operating mode, wherein the first fuel pump operates as in the first operating mode and the second fuel pump rotates in a reverse direction to supply fuel from the main fuel storage unit to the auxiliary fuel storage unit via a fourth fuel path.

[0037] The fuel supply system of the present invention achieves great improvement in performance through proper arrangement of the main fuel storage unit and the auxiliary fuel storage unit, forward and reverse rotation of the second fuel pump, and arrangement of the first fuel filter unit and the second fuel filter unit on the bypass fuel path.

[0038] In addition, in the event of a failure of the second fuel pump, since the first fuel pump is still in normal operation, the normal operation of the vehicle can still be ensured in a short period of time.

[0039] The fuel supply system of the present invention realizes a compact structure, complete functions (auxiliary exhaust, second fuel pumping, fuel replenishment, fuel filtering, drainage, pressure balance, fuel return heating, etc.) and an advanced fuel control method.

[0040] The auxiliary fuel storage unit has a smaller volume than the main fuel storage unit. Therefore, when the vehicle leaves the factory, only a small amount of fuel needs to be filled into the auxiliary fuel storage unit, which reduces the cost of the vehicle. In addition, the dual fuel storage unit solution can improve the fuel utilization of the main fuel storage unit.

[0041] The second fuel pump can rotate in a forward direction or a reverse direction as required, thereby achieving exhaust before starting the fuel supply system, pumping of the second fuel, and replenishing fuel to the auxiliary fuel storage unit.

[0042] Compared with the conventional fuel supply system, both the first fuel filter and the second fuel filter are not on the main fuel path (first fuel path) of the fuel supply system, and their flow resistance will not be consumed by the first fuel pump. Therefore, the capacity of the first fuel pump and the power of the internal combustion engine are more sufficient. At the same time, the pressure difference of the first / second fuel filter unit can be reduced, which can further extend the life of the first / second fuel filter unit, or reduce the volume of the first / second fuel filter unit, making the system more compact and reducing the cost.

[0043] The fuel supply system may further include a fuel return control valve that communicates with the fuel injection unit via a fuel return line and distributes the fuel of the fuel return line via first, second, and third return pipes as needed to heat the interior of the auxiliary fuel storage unit, the inlet of the second fuel filter, and the main fuel storage unit, respectively. In this regard, the fuel supply system makes full use of its heat, thereby ensuring proper operation of the engine at low temperatures.

[0044] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present disclosure will be more fully understood from the detailed description and accompanying drawings, wherein:

[0046] Figure 1 is a schematic diagram of a fuel supply system of the present invention.

[0047] Figure 2 A first operating mode of the fuel supply system of the present invention is shown, in which the first fuel pump is turned on and the second fuel pump is turned off.

[0048] Figure 3 A second operating mode of the fuel supply system of the present invention is shown in which the first fuel pump is turned on and the second fuel pump is turned on to rotate in the forward direction.

[0049] Figure 4 A third operating mode of the fuel supply system of the present invention is shown in which the first fuel pump is turned on and the second fuel pump is turned on to rotate in the reverse direction. DETAILED DESCRIPTION

[0050] As used herein, words such as “upper,” “lower,” “left,” and “right” used herein to define directions generally refer to and are understood as directions associated with the drawings and directions in actual applications.

[0051] As used herein, the term "vehicle" may be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger vehicles, commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles (ATVs), motorcycles, agricultural equipment, watercraft, aircraft, etc. In an example, the vehicle includes a body having a passenger cabin, a plurality of wheels mounted to the body, and other standard original equipment.

[0052] As used herein, the terms "downstream" or "upstream" may be used to refer to a direction relative to the direction of fuel flow.

[0053] Reference is now made to the drawings, wherein like reference numerals refer to like features throughout the several views. Figure 1 is a schematic diagram of a fuel supply system 100 for a vehicle according to the present invention.

[0054] like Figure 1 As shown in FIG. 1 , a fuel supply system 100 includes a fuel injection unit 1 configured to inject fuel into an internal combustion engine. The fuel injection unit 1 includes, but is not limited to, a high-pressure pump, a common rail, an injector, and other suitable components as required.

[0055] In addition, the fuel supply system 100 also includes: a main fuel storage unit 4, configured to store unfiltered fuel; and an auxiliary fuel storage unit 3, having a smaller volume than the main fuel storage unit 4 and configured to store filtered fuel. As a non-limiting example, the auxiliary fuel storage unit 3 may have a volume of 1 / 3-1 / 5 of the volume of the main fuel storage unit 4. However, as will be appreciated by those skilled in the art, the auxiliary fuel storage unit 3 may have any other suitable volume relative to the volume of the main fuel storage unit 4, such as 1 / 6, without departing from the scope of the present disclosure. As a non-limiting example, the auxiliary fuel storage unit 3 and the main fuel storage unit 4 may be arranged one after another on one side of the vehicle frame. However, as will be appreciated by those skilled in the art, the auxiliary fuel storage unit 3 and the main fuel storage unit 4 may also be arranged side by side on the vehicle frame without departing from the scope of the present disclosure.

[0056] In addition, the fuel supply system 100 further includes a first fuel pump 7; and a second fuel pump 12. The first fuel pump 7 is connected to the fuel injection unit 1 at its positive pressure side. The first fuel pump 7 is connected to the first node 61 at its negative pressure side, and the first node 61 is in turn connected to the auxiliary fuel storage unit 3 via the first fuel path A without the second fuel pump 12 and the third fuel path C with the second fuel pump 12 via the second node 62, and connected to the auxiliary fuel storage unit 3 via the second fuel path B. In the first fuel path, the filtered fuel flows from the auxiliary fuel storage unit 3 to the fuel injection unit 1 through the first fuel pump 7; in the second fuel path, the fuel flows from the main fuel storage unit 4 to the fuel injection unit 1. The second node 62 also connects the main fuel storage unit 4 with the auxiliary fuel storage unit 3 via the fourth fuel path D.

[0057] As a non-limiting example, the fuel supply system 100 is configured to be controlled to selectively operate in a first operating mode, a second operating mode, and a third operating mode, in which, in the first operating mode, the first fuel pump 7 is turned on and the second fuel pump 12 is turned off; in the second operating mode, the first fuel pump 7 is turned on and the second fuel pump 12 is turned on to rotate in a forward direction; in the third operating mode, the first fuel pump 7 is turned on and the second fuel pump 12 is turned on to rotate in a reverse direction.

[0058] The fuel supply system 100 further includes an electronic control unit 2 configured to receive and feed back various signals on the vehicle and control the fuel supply system 100 to selectively operate in a first operation mode, a second operation mode, and a third operation mode.

[0059] The fuel supply system 100 further includes a first fuel sensor (8) disposed in the auxiliary fuel storage unit 3 and configured to sense the fuel level of the auxiliary fuel storage unit 3 and a second fuel sensor 18 disposed in the main fuel storage unit 4 and configured to sense the fuel level of the main fuel storage unit 4.

[0060] The fuel supply system 100 also includes a first fuel filter 19 and a second fuel filter 13 both disposed downstream of the main fuel storage unit 4, wherein in the second fuel path, unfiltered fuel flows from the main fuel storage unit 4 through the first fuel filter 19, the second fuel filter 13, and the first fuel pump 7 to the fuel injection unit 1; in the fourth fuel path, unfiltered fuel flows from the main fuel storage unit 4 through the first fuel filter 19, the second fuel filter 13, and the second fuel pump 12 to the auxiliary fuel storage unit 3. The first fuel filter 19 is configured to filter out particles from the fuel, and the second fuel filter 13 is configured to filter out both particles and water from the fuel. However, as will be appreciated by those skilled in the art, the first fuel filter 19 and the second fuel filter 13 may also be configured to filter out other impurities as desired without departing from the scope of the present disclosure.

[0061] The fuel supply system 100 further includes a first check valve 9 disposed between the first fuel pump 7 / first node 61 and the auxiliary fuel storage unit 3 and configured to prevent the fuel from flowing back to the auxiliary fuel storage unit 3. The fuel supply system 100 further includes a second check valve 10 disposed between the first fuel pump 7 and the second fuel pump 12. Specifically, the second check valve 10 is disposed between the first node 61 and the second node 62 and configured to prevent the fuel from flowing back to the auxiliary fuel storage unit 3.

[0062] The fuel supply system 100 also includes a third check valve 11, which is disposed between the main fuel storage unit 4 and the second fuel pump 12 / second node 62, and is configured to prevent the fuel from flowing back to the main fuel storage unit 4. The fuel supply system 100 also includes: a pressure balance line 55, which is disposed between the main fuel storage unit 4 and the auxiliary fuel storage unit 3, and is configured to discharge excess gas or fuel from the auxiliary fuel storage unit 3 to the main fuel storage unit 4; and a fourth check valve 16, which is disposed in the pressure balance line 55 and is configured to prevent the gas or fuel from flowing back to the auxiliary fuel storage unit 3 from the main fuel storage unit 4. As a non-limiting example, the first check valve 9, the second check valve 10, the third check valve 11, and the fourth check valve 16 may have the same structure. However, as will be understood by those skilled in the art, the first check valve 9, the second check valve 10, the third check valve 11, and the fourth check valve 16 may have different structures as needed without departing from the scope of the present disclosure.

[0063] The fuel supply system 100 may further include a third fuel filter unit 6 disposed on the positive pressure side of the first fuel pump 7 and a pressure sensor 5 disposed on the positive pressure side of the first fuel pump 7 at the downstream end of the third fuel filter unit 6. The pressure sensor 5 is used to monitor whether the fuel supply pressure is abnormal. The third fuel filter unit 6 filters the fuel downstream of the first fuel pump 7 to protect downstream components.

[0064] The fuel supply system 100 may further include a first water level sensor and a drain valve assembly 23 disposed in the third fuel filter unit 6 and configured to sense the water level in the third fuel filter unit 6 and drain water out of the third fuel filter unit 6 when the water level in the third fuel filter unit 6 is above a certain threshold.

[0065] The fuel supply system 100 may also include a first integrated fuel filler and breathing valve assembly 21, which is disposed on the top of the main fuel storage unit 4 and is configured to fill the main fuel storage unit 4 with fuel as needed and balance the internal pressure in the main fuel storage unit 4 with the external atmospheric pressure. Similarly, the fuel supply system 100 may also include a second integrated fuel filler and breathing valve assembly 15, which is disposed on the top of the auxiliary fuel storage unit 3 and is configured to fill the auxiliary fuel storage unit 3 with filtered fuel as needed and balance the internal pressure in the auxiliary fuel storage unit 3 with the external atmospheric pressure. The first integrated fuel filler and breathing valve assembly 21 and the second integrated fuel filler and breathing valve assembly 15 may have the same structure. However, as will be understood by those skilled in the art, the first integrated fuel filler and breathing valve assembly 21 and the integrated fuel filler and breathing valve assembly 15 may have different structures as needed without departing from the scope of the present disclosure. In addition, as will be appreciated by those skilled in the art, each of the first integrated fuel filler and breathing valve assembly 21 and the integrated fuel filler and breathing valve assembly 15 may include a separate fuel filler and breathing valve as desired, rather than being integrated into a one-piece component, without departing from the scope of the present disclosure.

[0066] The fuel supply system 100 may also include a breather valve filter 20 that filters air interacting with the outside atmosphere from the first integrated fuel filler and breather valve assembly 21. A similar breather valve filter (not shown) may also be provided adjacent to the second integrated fuel filler and breather valve assembly 15.

[0067] The fuel supply system 100 may further include a fuel return control valve 17 that communicates with the fuel injection unit 1 via a fuel return line 58, and distributes the fuel of the fuel return line 58 via the first, second, and third return pipes 52, 54, 57 as needed to heat the interior of the auxiliary fuel storage unit 3, the inlet of the second fuel filter 13, and the main fuel storage unit 4, respectively. In this regard, the fuel supply system 100 makes full use of its heat, thereby ensuring proper operation of the engine at low temperatures.

[0068] The fuel supply system 100 may further include: a water storage tank 14 connected to the second fuel filter 13 and configured to collect water filtered by the second fuel filter 13; and a second water level sensor and discharge valve assembly 22, disposed in the water storage tank 14, and configured to sense the water level in the water storage tank 14, and discharge water out of the water storage tank 14 when the water level in the water storage tank 14 is above a certain threshold. As a non-limiting example, the water storage tank 14 may be disposed in the auxiliary fuel storage unit 3 and communicate with the second fuel filter 13 via a pipe 53. However, as will be appreciated by those skilled in the art, the water storage tank 14 may be disposed separately from the auxiliary fuel storage unit 3 or integrated in the second fuel filter 13 as desired without departing from the scope of the present disclosure.

[0069] Figure 2 A first operating mode of the fuel supply system 100 of the present invention is shown. Figure 3 A second mode of operation of the fuel supply system 100 of the present invention is shown. Figure 4 A third mode of operation of the fuel supply system 100 of the present invention is shown.

[0070] As a non-limiting example, the electronic control unit 2 is configured to control the fuel supply system 100 to operate in a first operation mode when the vehicle is operating normally, wherein the first fuel pump 7 pumps fuel to the fuel injection unit 1 via the first fuel path A and the second fuel path B. Figure 2 As shown in the figure, in the first fuel path A, the filtered fuel flows from the auxiliary fuel storage unit 3 through the pipeline 50, the first check valve 9, the first node 61, the first fuel pump 7, and the third fuel filter unit 6 to the fuel injection unit 1; in the second fuel path B, the fuel flows from the main fuel storage unit 4 through the first fuel filter 19, the pipeline 56, the second fuel filter 13, the third check valve 11, the second node 62, the second check valve 10, the first node 61, the first fuel pump 7, and the third fuel filter unit 6 to the fuel injection unit 1.

[0071] As a non-limiting example, the electronic control unit 2 is configured to control the fuel supply system 100 to operate in the second operation mode when the vehicle is started, the resistance of the fuel supply system 100 is equal to or greater than the first threshold, and / or the vehicle is on an uphill or downhill slope, wherein the first fuel pump 7 operates as in the first operation mode, and the second fuel pump 12 rotates in the forward direction to supply fuel to the fuel injection unit 1 via the third fuel path C. Figure 3 In the third fuel path C shown in FIG, the filtered fuel flows from the auxiliary fuel storage unit 3 through the pipeline 51, the second fuel pump 12, the second node 62, the second check valve 10, the first node 61, the first fuel pump 7, and the third fuel filter unit 6 to the fuel injection unit 1.

[0072] As a non-limiting example, the electronic control unit 2 is configured to control the fuel supply system 100 to operate in the third operation mode when the fuel level of the auxiliary fuel storage unit 3 is lower than the second threshold value, wherein the first fuel pump 7 operates as in the first operation mode, and the second fuel pump 12 rotates in the reverse direction to supply fuel from the main fuel storage unit 4 to the auxiliary fuel storage unit 3 via the fourth fuel path D, thereby replenishing the auxiliary fuel storage unit 3 with fuel. Figure 4 In the fourth fuel path D shown in FIG. 1 , unfiltered fuel flows from the main fuel storage unit 4 through the first fuel filter 19 , the pipe 56 , the second fuel filter 13 , the third check valve 11 , the second node 62 , the second fuel pump 12 , the pipe 51 to the auxiliary fuel storage unit 3 .

[0073] A fuel control method using the fuel supply system 100 is also provided, comprising: when the vehicle is operating normally, controlling the fuel supply system 100 to operate in a first operation mode, wherein the first fuel pump 7 pumps fuel to the fuel injection unit 1 via the first fuel path A and the second fuel path B; in the first fuel path, filtered fuel flows from the auxiliary fuel storage unit 3 to the fuel injection unit 1 through the first fuel pump 7; in the second fuel path, fuel flows from the main fuel storage unit 4 to the fuel injection unit 1; when the vehicle is started, the resistance of the fuel supply system 100 is equal to or greater than the first threshold value, and / or the vehicle is on an uphill or downhill slope, controlling the fuel supply system 100 to operate in a second operation mode , wherein the first fuel pump 7 operates as in the first operating mode, the second fuel pump 12 rotates in the forward direction to supply fuel to the fuel injection unit 1 via a third fuel path C, in which the filtered fuel flows from the auxiliary fuel storage unit 3 to the fuel injection unit 1 through the second fuel pump 12 and the first fuel pump 7; and when the fuel level of the auxiliary fuel storage unit 3 is lower than a second threshold value, the fuel supply system 100 is controlled to operate in a third operating mode, wherein the first fuel pump 7 operates as in the first operating mode, and the second fuel pump 12 rotates in the reverse direction to supply fuel from the main fuel storage unit 4 to the auxiliary fuel storage unit 3 via a fourth fuel path D.

[0074] Through the proper arrangement of the main fuel storage unit 4 and the auxiliary fuel storage unit 3, the forward and reverse rotation of the second fuel pump 12, and the arrangement of the first fuel filter unit 19 and the second fuel filter unit 13 on the bypass fuel path (that is, not on the first fuel path A), the fuel supply system 100 of the present invention achieves great improvement in performance.

[0075] In addition, in the event that the second fuel pump 12 fails, since the first fuel pump 7 is still in normal operation, the normal operation of the vehicle can still be ensured in a short period of time.

[0076] The fuel supply system 100 of the present invention realizes a compact structure, complete functions (auxiliary exhaust, second fuel pumping, fuel replenishment, fuel filtering, drainage, pressure balance, fuel return heating, etc.) and an advanced fuel control method.

[0077] The auxiliary fuel storage unit 3 has a smaller volume than the main fuel storage unit 4. Therefore, when the vehicle leaves the factory, only a small amount of fuel needs to be filled into the auxiliary fuel storage unit 3, which reduces the cost of the vehicle. In addition, the dual fuel storage unit solution can improve the fuel utilization of the main fuel storage unit 3.

[0078] The second fuel pump 12 may rotate in a forward direction or a reverse direction as required, thereby achieving exhaust before the fuel supply system 100 is started, second fuel pumping, and fuel replenishment to the auxiliary fuel storage unit 3 .

[0079] Compared with the conventional fuel supply system, both the first fuel filter 19 and the second fuel filter 13 are not on the main fuel path (first fuel path A) of the fuel supply system, and their flow resistance will not be consumed by the first fuel pump 7. Therefore, the capacity of the first fuel pump 7 and the power of the internal combustion engine are more sufficient. At the same time, the pressure difference of the first / second fuel filter unit can be reduced, which can further extend the life of the first / second fuel filter unit, or reduce the volume of the first / second fuel filter unit, making the system more compact and reducing the cost.

[0080] Various aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise configurations and compositions disclosed herein; any and all modifications, variations and modifications apparent from the foregoing description are within the scope of the present disclosure as defined by the appended claims. Furthermore, the present concept expressly includes any and all combinations and sub-combinations of the foregoing elements and features.

Claims

1. A fuel supply system (100) for a vehicle, comprising: A fuel injection unit (1) configured to inject fuel into an internal combustion engine; a main fuel storage unit (4) configured to store unfiltered fuel; an auxiliary fuel storage unit (3) having a smaller volume than the main fuel storage unit (4) and configured to store filtered fuel; a first fuel pump (7); and a second fuel pump (12), wherein the first fuel pump (7) is connected to the fuel injection unit (1) at its positive pressure side, is connected to the auxiliary fuel storage unit (3) at its negative pressure side via a first fuel path (A) without a second fuel pump (12) and a third fuel path (C) with a second fuel pump (12), and is connected to the auxiliary fuel storage unit (3) via a second fuel path (B), and The fuel supply system (100) is configured to be controlled to selectively operate in the following modes: a first operating mode, in which the first fuel pump (7) is turned on and the second fuel pump (12) is turned off; a second operating mode, in which the first fuel pump (7) is turned on and the second fuel pump (12) is turned on to rotate in a forward direction; and A third operating mode, in which the first fuel pump (7) is turned on and the second fuel pump (12) is turned on to rotate in the reverse direction.

2. The fuel supply system (100) according to claim 1, further comprising an electronic control unit (2), wherein the electronic control unit (2) is configured to control the fuel supply system (100) to selectively operate in the first operating mode, the second operating mode and the third operating mode.

3. The fuel supply system (100) according to claim 2, wherein: The electronic control unit (2) is configured to control the fuel supply system (100) to: When the vehicle is operating normally, it operates in a first operation mode, wherein the first fuel pump (7) pumps fuel to the fuel injection unit (1) via a first fuel path (A) and a second fuel path (B), in which the filtered fuel flows from the auxiliary fuel storage unit (3) through the first fuel pump (7) to the fuel injection unit (1), and in the second fuel path (B), the fuel flows from the main fuel storage unit (4) to the fuel injection unit (1); When the vehicle is started, the resistance of the fuel supply system (100) is equal to or greater than the first threshold value, and / or the vehicle is on an uphill or downhill slope, operating in a second operation mode, wherein the first fuel pump (7) operates as in the first operation mode, and the second fuel pump (12) rotates in a forward direction to supply fuel to the fuel injection unit (1) via a third fuel path (C), in which filtered fuel flows from the auxiliary fuel storage unit (3) through the second fuel pump (12) and the first fuel pump (7) to the fuel injection unit (1); and When the fuel level of the auxiliary fuel storage unit (3) is below a second threshold, operation is performed in a third operating mode, wherein the first fuel pump (7) operates as in the first operating mode and the second fuel pump (12) rotates in a reverse direction to supply fuel from the main fuel storage unit (4) to the auxiliary fuel storage unit (3) via a fourth fuel path (D).

4. The fuel supply system (100) according to claim 3, further comprising a first fuel sensor (8) disposed in the auxiliary fuel storage unit (3) and configured to sense a fuel level of the auxiliary fuel storage unit (3).

5. The fuel supply system (100) according to claim 4, further comprising a second fuel sensor (18) disposed in the main fuel storage unit (4) and configured to sense a fuel level of the main fuel storage unit (4).

6. The fuel supply system (100) according to claim 5, further comprising a first fuel filter (19) and a second fuel filter (13) both disposed downstream of the main fuel storage unit (4), in, In the second fuel path (B), unfiltered fuel flows from the main fuel storage unit (4) through the first fuel filter (19), the second fuel filter (13), the first fuel pump (7) to the fuel injection unit (1), and In a fourth fuel path (D), unfiltered fuel flows from the main fuel storage unit (4) through the first fuel filter (19), the second fuel filter (13) and the second fuel pump (12) to the auxiliary fuel storage unit (3).

7. The fuel supply system (100) according to claim 6, further comprising: a first check valve (9) disposed between the first fuel pump (7) and the auxiliary fuel storage unit (3) and configured to prevent the fuel from flowing back to the auxiliary fuel storage unit (3); a second check valve (10) disposed between the first fuel pump (7) and the second fuel pump (12) and configured to prevent fuel from flowing back to the auxiliary fuel storage unit (3); and A third check valve (11) is disposed between the main fuel storage unit (4) and the second fuel pump (12) and is configured to prevent the fuel from flowing back to the main fuel storage unit (4).

8. The fuel supply system (100) according to claim 7, further comprising: a pressure equalization line (55) disposed between the main fuel storage unit (4) and the auxiliary fuel storage unit (3) and configured to discharge excess gas or fuel from the auxiliary fuel storage unit (3) into the main fuel storage unit (4); and A fourth check valve (16) is disposed in the pressure equalization line (55) and is configured to prevent gas or fuel from flowing back from the primary fuel storage unit (4) to the auxiliary fuel storage unit (3).

9. The fuel supply system (100) according to claim 6, wherein: The first fuel filter (19) is configured to filter particles from the fuel, and The second fuel filter (13) is configured to filter both particulates and water from the fuel.

10. The fuel supply system (100) according to claim 6 further includes a fuel return control valve (17), which is connected to the fuel injection unit (1) via a fuel return pipeline (58) and is configured to distribute the fuel of the fuel return pipeline (58) via the first, second and third return pipes (52, 54, 57) as needed to heat the interior of the auxiliary fuel storage unit (3), the inlet of the second fuel filter (13) and the main fuel storage unit (4), respectively.

11. A fuel control method using the fuel supply system (100) according to claim 1, the fuel control method comprising: When the vehicle is operating normally, the fuel supply system (100) is controlled to operate in a first operation mode, wherein the first fuel pump (7) pumps fuel to the fuel injection unit (1) via a first fuel path (A) and a second fuel path (B), in which the filtered fuel flows from the auxiliary fuel storage unit (3) through the first fuel pump (7) to the fuel injection unit (1), and in which the fuel flows from the main fuel storage unit (4) to the fuel injection unit (1); When the vehicle is started, the resistance of the fuel supply system (100) is equal to or greater than a first threshold value, and / or the vehicle is on an uphill or downhill slope, the fuel supply system (100) is controlled to operate in a second operation mode, wherein the first fuel pump (7) operates as in the first operation mode, and the second fuel pump (12) rotates in a forward direction to supply fuel to the fuel injection unit (1) via a third fuel path (C), in which filtered fuel flows from the auxiliary fuel storage unit (3) through the second fuel pump (12) and the first fuel pump (7) to the fuel injection unit (1); and When the fuel level of the auxiliary fuel storage unit (3) is below a second threshold value, the fuel supply system (100) is controlled to operate in a third operating mode, wherein the first fuel pump (7) operates as in the first operating mode and the second fuel pump (12) rotates in a reverse direction to supply fuel from the main fuel storage unit (4) to the auxiliary fuel storage unit (3) via a fourth fuel path (D).

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