WO2014154159A1

WO2014154159A1 - Fuel supply system and fuel supply control method for engine of vehicle

Info

Publication number: WO2014154159A1
Application number: PCT/CN2014/074190
Authority: WO
Inventors: Song Li; Yanjun Chen; Decai DENG; Qingyan SU; Lin Ren
Original assignee: BYD Co Ltd; Shenzhen BYD Auto R&D Co Ltd
Current assignee: BYD Co Ltd; Shenzhen BYD Auto R&D Co Ltd
Priority date: 2013-03-28
Filing date: 2014-03-27
Publication date: 2014-10-02
Anticipated expiration: 2015-09-28
Also published as: CN104074648B; CN104074648A

Abstract

A fuel supply system (1000) and a fuel supply control method for an engine (60) of a vehicle are provided. The fuel supply system (1000) includes: a first detecting unit (10) configured to detect an operating state of the vehicle to generate an operating state signal; an engine control unit (20) connected with the first detecting unit (10) and configured to obtain an opening degree of a throttle valve according to the operating state signal, to obtain a current fuel demand according to the opening degree, and to generate a fuel demand control signal based on the current fuel demand; a fuel pump (30) configured to supply fuel to the engine (60); a fuel pump motor (40) configured to drive the fuel pump (30); and a fuel pump motor control unit (50) connected with the fuel pump motor (40) and the engine control unit (20) respectively and configured to control the fuel pump motor (40) according to the fuel demand control signal.

Description

FUEL SUPPLY SYSTEM AND FUEL SUPPLY CONTROL METHOD FOR

ENGINE OF VEHICLE

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority and benefits of Chinese Patent Application No. 201310105913.5, filed with State Intellectual Property Office, P. R. C. on March 28, 2013, the entire content of which is incorporated herein by reference. FIELD

Embodiments of the present disclosure generally relate to a vehicle, and more particularly to a fuel supply system of an engine of a vehicle and a fuel supply control method for an engine of a vehicle. BACKGROUND

Conventional fuel supply systems for an engine of a vehicle generally aim at supplying adequate fuel to the engine in a variety of driving conditions, including when the engine is at idle.

However, with increasingly stringent restrictions on emissions and energy consumption, the conventional fuel supply systems face a huge challenge.

The conventional fuel supply systems are typically classified into following several types.

1. The fuel is pumped to the engine by a fuel pump, and residual fuel flows to a fuel tank with the aid of a pressure regulator. However, a temperature of the fuel in the fuel tank of such fuel supply system is increased due to a high temperature of the backflow fuel, thus resulting in that generated vapor is difficult to meet the Evaporative emission requirements.

2. The fuel pump is combined with a fuel filter by adding a pressure regulator to form a fuel pump module and the fuel pump module is mounted in the fuel tank. The fuel pumped by the fuel pump is firstly filtered by the fuel filter and regulated by the pressure regulator, and then a part of the fuel is pumped to the engine. The other part of the fuel is returned to the fuel tank by the pressure regulator so as to restrain an increment of the fuel temperature, thus reducing the possibility to generate vapor. However, once the vehicle is powered on, the fuel pump starts to work continuously, and thus the energy waste problem caused by pumping fuel and then draining fuel cannot be solved. For example, providing a pressure of the fuel pump is about 6.6bar, a working flow of a fuel line under the pressure is 77L/h, while the engine consumes only 3L/h. Thus, 96% of the fuel is returned to the fuel tank. SUMMARY

Embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent.

For this, one objective of the present disclosure is to provide a fuel supply system for an engine of a vehicle, which can perform a fuel supply in real time according to a current fuel demand of the engine, realize an intelligent fuel supply for the engine, has high safety and no pollution, and reduce a cost.

Another objective of the present disclosure is to provide a fuel supply control method for an engine of a vehicle.

According to embodiments of a first broad aspect of the present disclosure, a fuel supply system for an engine of a vehicle is provided. The fuel supply system includes: a first detecting unit, configured to detect an operating state of the vehicle to generate an operating state signal; an engine control unit, connected with the first detecting unit and configured to obtain an opening degree of a throttle valve according to the operating state signal when the engine is working, to query a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands to obtain a current fuel demand, and to generate a fuel demand control signal based on the current fuel demand; a fuel pump, configured to supply fuel to the engine; a fuel pump motor, configured to drive the fuel pump; and a fuel pump motor control unit, connected with the fuel pump motor and the engine control unit respectively and configured to control the fuel pump motor according to the fuel demand control signal.

With the fuel supply system for an engine of a vehicle according to embodiments of the present disclosure, the fuel pump can supply fuel to the engine in real time according to the current fuel demand of the engine, thus realizing an intelligent and precise fuel supply, improving an efficiency of the fuel pump motor, reducing energy waste from fuel pumping to fuel returning, and having advantages of noiselessness, long service life, low pollution, safety and environment-friendliness. Furthermore, with the fuel supply system according to embodiments of the present disclosure, a number of fuel returning lines can be decreased, thus having advantages of compact spatial arrangement, less components and low manufacturing cost.

According to embodiments of a second broad aspect of the present disclosure, a fuel supply control method for an engine of a vehicle is provided. The method includes: detecting an operating state of a vehicle to generate an operating state signal when the engine is working; obtaining an opening degree of a throttle valve according to the operating state signal, querying a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands to obtain a current fuel demand, and generating a fuel demand control signal based on the current fuel demand; and controlling a fuel pump motor of the vehicle according to the fuel demand control signal.

With the fuel supply control method for the engine of the vehicle according to embodiments of the present disclosure, a fuel supply to the engine can be performed in real time according to the current fuel demand of the engine, thus realizing an intelligent and precise fuel supply, improving an efficiency of the fuel pump motor, reducing energy waste from fuel pumping to fuel returning, and having advantages of noiselessness, long service life, low pollution, safety and environment- friendliness when supplying fuel. Furthermore, the method is easy to implement.

Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the accompanying drawings, in which:

Fig. 1 is a schematic diagram of a fuel supply system for an engine of a vehicle according to an embodiment of the present disclosure;

Fig. 2 is a schematic diagram of a fuel supply system for an engine of a vehicle according to another embodiment of the present disclosure;

Fig. 3 is a flow chart of a fuel supply control method for an engine of a vehicle according to an embodiment of the present disclosure; and

Fig. 4 is a flow chart of a fuel supply control method for an engine of a vehicle according to another embodiment of the present disclosure. DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure.

In addition, terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance. Thus, features limited by "first" and "second" are intended to indicate or imply including one or more than one these features. In the description of the present disclosure, "a plurality of relates to two or more than two.

In the description of the present disclosure, unless specified or limited otherwise, it should be noted that, terms "mounted," "connected" "coupled" and "fastened" may be understood broadly, such as permanent connection or detachable connection, electronic connection or mechanical connection, direct connection or indirect connection via intermediary, inner communication or interreaction between two elements. These having ordinary skills in the art should understand the specific meanings in the present disclosure according to specific situations.

In the description of the present disclosure, a structure in which a first feature is "on" a second feature may include an embodiment in which the first feature directly contacts the second feature, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature so that the first feature does not directly contact the second feature, unless otherwise specified. Furthermore, a first feature "on," "above," or "on top of a second feature may include an embodiment in which the first feature is right "on," "above," or "on top of the second feature, and may also include an embodiment in which the first feature is not right "on," "above," or "on top of the second feature, or just means that the first feature has a sea level elevation larger than the sea level elevation of the second feature. While first feature "beneath," "below," or "on bottom of a second feature may include an embodiment in which the first feature is right "beneath," "below," or "on bottom of the second feature, and may also include an embodiment in which the first feature is not right "beneath," "below," or "on bottom of the second feature, or just means that the first feature has a sea level elevation smaller than the sea level elevation of the second feature.

In the following, a fuel supply system for an engine of a vehicle according to embodiments of the present disclosure will be described with reference to Figs. 1-2.

Fig. 1 is a schematic diagram of a fuel supply system for an engine of a vehicle according to an embodiment of the present disclosure. As shown in Fig. 1, the fuel supply system 1000 includes a first detecting unit 10, an engine control unit 20, a fuel pump 30, a fuel pump motor 40, and a fuel pump motor control unit 50.

The first detecting unit 10 is configured to detect an operating state of the vehicle to generate an operating state signal. For example, the first detecting unit 10 detects whether the vehicle is in an accelerating or a decelerating operation state, that is, the first detecting unit 10 detects a driver's driving intention.

In an embodiment, the first detecting unit 10 may be configured as a sensor. In embodiments of the present disclosure, the sensor refers to a device for measuring respective instantaneous physical signal of an engine 60 or a vehicle, and converting the respective instantaneous physical signal to a corresponding electrical signal for calculating an instantaneous fuel demand of the engine 60. The sensor may be of different types and models.

The engine control unit (ECU) 20 is connected with the first detecting unit 10. The engine control unit 20 is configured to obtain an opening degree of a throttle valve according to the operating state signal when the engine 60 is working, to query a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands to obtain a current fuel demand, and to generate a fuel demand control signal based on the current fuel demand. The predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands may be stored in the engine control unit 20 in advance. The engine 60 may be configured as a port injection engine or a direct injection engine.

The fuel pump 30 is configured to supply fuel to the engine 60. The fuel pump motor 40 is disposed in a fuel tank 70 of the vehicle. The fuel pump motor 40 is configured to drive the fuel pump 30.

In an embodiment, the fuel pump motor 40 is a brushless variable-frequency motor. An armature winding of the brushless variable-frequency motor is disposed in a stator core. A permanent magnet is fixed to a rotor. The position of permanent magnet poles is detected by a rotor position sensor, and then a conduction state of a stator winding is determined, thus making the motor generate a stable and continuous electromagnetic torque.

The brushless variable-frequency motor is disposed inside a pump body of the fuel pump30 and controlled by the fuel pump motor control unit 50.

By replacing a brush motor with the brushless variable-frequency motor, a service life of the fuel pump 30 is prolonged, risk of generating sparks is reduced and safety is ensured.

In some embodiments of the present disclosure, the fuel pump motor control unit 50 is connected with the fuel pump motor 40 and the engine control unit 20 respectively. The fuel pump motor control unit 50 is configured to control the fuel pump motor 40 according to the fuel demand control signal. Specifically, the fuel pump motor control unit 50 queries a predetermined table indicating a relationship between rotating speeds of the fuel pump motor 40 and the fuel demands to obtain a rotating speed of the fuel pump motor 40 corresponding to the current fuel demand, and controls the fuel pump motor 40 according to the rotating speed of the fuel pump motor 40. The predetermined table indicating a relationship between rotating speeds of the fuel pump motor 40 and the fuel demands may be stored in the fuel pump motor control unit 50 in advance.

As shown in Fig.l and Fig.2, the fuel pump motor 40 is connected with a power source 110 via a power wire 80. The fuel pump motor 40 is also grounded. A voltage of the power source 110 can be 12V, 42V or 48V. The first detecting unit 10 may be connected with the engine control unit 20 via a CAN bus 90, and the engine control unit 20 may be connected with the fuel pump motor control unit 50 via the CAN bus 90. In other words, the first detecting unit 10 may communicate with the engine control unit 20 via a CAN network, and the engine control unit 20 may communicate with the fuel pump motor control unit 50 via the CAN network. That is, the fuel pump motor control unit 50 can communicate with the engine control unit 20 via the CAN network to obtain the fuel demand information of the engine 60 in real time, so that the fuel pump motor control unit 50 can supply the fuel precisely as actual demand by controlling the rotating speed of the fuel pump motor 40.

Further, in one embodiment of the present disclosure, as shown in Fig.2, a check valve 11 (also called as a pressure retaining valve) conducted along a direction from the fuel pump 30 to the engine 60 is disposed in a fuel supply line 100 between the engine 60 and the fuel pump 30. It should be noted that a number of the check valve 11 is not limited to be one, but also may be more than one. The check valve 11 is used to make the fuel flow one way and retain the fuel pressure.

In one embodiment of the present disclosure, as shown in Fig.2, the fuel supply system further includes a second detecting unit 12.

The second detecting unit 12 is configured to detect a fuel pressure of the fuel supply line 100 between the check valve 11 and the engine 60 (such as an electronic injection actuator of the engine 60). The second detecting unit 12 is connected with fuel pump motor control unit 50. The fuel pump motor control unit 50 is further configured to control the fuel pump motor according to the fuel pressure and the fuel demand control signal. In an embodiment, the second detecting unit 12 is a line pressure sensor.

When the fuel pressure is lower than a first predetermined threshold, the fuel pump motor control unit 50 increases the rotating speed of the fuel pump motor 40. When the fuel pressure reaches a second predetermined threshold, the fuel pump motor control unit 50 stops the fuel pump motor 40, in which the first predetermined threshold is lower than the second predetermined threshold. That is, when the fuel pressure is less than the first predetermined threshold, the fuel pump motor control unit 50 increases the rotating speed of the fuel pump motor 40 to increase the fuel supply, so as to enhance the fuel pressure of the fuel supply line 100, until the fuel pressure reaches the second predetermined threshold. It should be understood that the first predetermined threshold can be set according to actual conditions. Specifically, when the fuel pressure detected by the line pressure sensor is less than the first predetermined threshold, the fuel pump motor control unit 50 controls the fuel pump motor 40 to increase the rotating speed so as to supply more fuel than the engine control unit 20 requires. When the fuel pressure detected by the line pressure sensor reaches the second predetermined threshold, the fuel pump motor control unit 50 controls the fuel pump motor 40 to stop, so as to stop supplying fuel. In other words, the fuel pump motor control unit 50 controls the rotating speed of the fuel pump motor 40 according to the detected fuel pressure and the fuel demand control signal. When there is a conflict between the fuel pressure and the fuel demand control signal, the fuel pressure shall prevail. For example, when the engine control unit 20 sends the fuel demand control signal indicating to increase the fuel supply, the fuel pump motor control unit 50 should control the fuel pump motor 40 to increase the rotating speed so to supply fuel on demand. However, if the line pressure sensor detects that the fuel pressure has reached the second predetermined threshold at this time, the fuel pump motor control unit 50 controls the fuel pump motor 40 to stop rotating in practice, so as to avoid a further increment of the fuel pressure.

In some embodiments of the present disclosure, after the vehicle is powered on and before the engine 60 is started, the fuel pump motor control unit 50 controls the fuel pump motor 40 to rotate so as to drive the fuel pump 30, and opens the check valve 11, thus supplying fuel into the fuel supply line 100. The fuel flows to the engine 60 through the check valve 11, and generate a fuel pressure in the fuel path 100 from the check valve 11 to the engine 60. The line pressure sensor detects the fuel pressure. When the fuel pressure has reached the second predetermined threshold, the fuel pump motor control unit 50 controls the fuel pump motor 40 to stop rotating and closes the check valve 11, so that the fuel pressure in the fuel path 100 from the check valve 11 to the engine 60 is unchanged.

After the engine is stopped, the engine control unit 20 stops sending the fuel demand control signal to the fuel pump motor control unit 50, the fuel pump motor control unit 50 controls the fuel pump motor 40 to stop rotating and closes the check valve 11, thus preventing the fuel from returning.

In conclusion, according to embodiments of the present disclosure, the fuel supply system can supply fuel in real time according to the engine's fuel demand, and has advantages of intelligent fuel supply, high safety and non-pollution.

Furthermore, a fuel return line is cancelled in the fuel supply system according to the present disclosure, which may reduce the cost, and solve a vapor emission problem resulting from frequent fuel flowing. Moreover, by applying the brushless variable-frequency motor rather than the brush motor to the fuel supply system, the service life of the fuel pump is prolonged, the risk of generating sparks is reduced and safety is ensured.

A fuel supply control method for an engine of a vehicle will be described below with reference to Figs. 3 and 4.

Fig. 3 is a flow chart of a fuel supply control method for an engine of a vehicle according to an embodiment of the present disclosure. As shown in Fig. 3, the method includes following steps.

At step S I, when the engine is working, an operating state of a vehicle is detected to generate an operating state signal.

Specifically, when the engine is working, a sensor detects the operating state of the vehicle in real time and generates the operating state signal. The sensor refers to a device for measuring respective instantaneous physical signal of the engine or the vehicle and converting the respective instantaneous physical signal to a corresponding electric signal for calculating an instantaneous fuel demand of the engine. The sensor may be of different types and models.

At step S2, an opening degree of a throttle valve is obtained according to the operating state signal, a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands is queried to obtain a current fuel demand, and a fuel demand control signal is generated based on the current fuel demand.

Specifically, the predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands (i.e., a fuel supply demand model of the engine under different sensor signals) may be pre- stored in an engine control unit.

At step S3, a fuel pump motor is controlled according to the fuel demand control signal.

In some embodiments of the present disclosure, when receiving the fuel demand control signal, a predetermined table indicating a relationship between rotating speeds of the fuel pump motor and the fuel demands is queried to obtain a rotating speed of the fuel pump motor corresponding to the current fuel demand, and then the fuel pump motor is controlled according to the rotating speed of the fuel pump motor.

The predetermined table indicating a relationship between rotating speeds of the fuel pump motor and the fuel demands (i.e., a fuel supply model of the fuel pump motor under different rotating speeds) may be pre- stored in a fuel pump motor control unit. In an embodiment, the fuel pump motor is a brushless variable-frequency motor.

Fig. 4 is a flow chart of a fuel supply control method for an engine of a vehicle according to another embodiment of the present disclosure. As shown in Fig. 4, the method includes following steps.

At step S 101, a driver's driving intention is sent out. That is, the driver's driving intention is embodied by the operating state of the vehicle or the engine, which is detected by the sensor to generate the operating state signal for sending to the engine control unit.

At step S 102, an instantaneous fuel demand is calculated according to a preset fuel supply demand model. The engine control unit calculates the instantaneous fuel demand according to the preset fuel supply demand model when receiving the operating state signal, and generates a fuel demand control signal according to the instantaneous fuel demand.

At step S 103, the instantaneous fuel demand is sent out. The engine control unit sends the fuel demand control signal to the fuel pump motor control unit via the CAN network and controls the injection actuator to inject fuel and burn.

At step S 104, an instantaneous control strategy for the fuel pump motor is calculated according to a fuel supply model. The fuel pump motor control unit receives the fuel demand control signal, obtains the rotating speed of the fuel pump motor according to the preset fuel supply model of the fuel pump under different rotating speeds, and controls the fuel pump motor to drive the fuel pump to supply fuel according to the obtained rotating speed. At this time, a check valve disposed in the fuel supply line between the engine and the fuel pump is open, so as to ensure the fuel pressure of the fuel supply line.

At step S 105, the fuel pressure of the fuel supply line between the engine and the fuel pump is detected. A line pressure sensor is used to detect the fuel pressure in real time, and to send the detected fuel pressure to the fuel pump motor control unit.

At step S 106, it is determined whether the fuel pressure is within a normal range, for example between a first predetermined threshold and a second predetermined threshold (the first predetermined threshold is lower than the second predetermined threshold); if yes, execute step S107; and if no, execute step S 108.

At step S 107, the fuel pump motor control unit controls the fuel pump motor to rotate at a speed corresponding to the instantaneous fuel demand, and then execute step S il l.

At step S 108, it is determined whether the fuel pressure of the fuel supply line is lower than the first predetermined threshold; if yes, execute step S109; and if no, execute step S I 10.

At step S109, the rotating speed of the fuel pump motor is increased so as to control the fuel pump to supply more fuel.

At step S I 10, it is determined whether the fuel pressure of the fuel supply line reaches the second predetermined threshold; if yes, execute step S I 12; and if no, execute step S ill.

At step S ill, the fuel pump is controlled to supply fuel normally.

At step S I 12, the fuel pump motor is stopped.

At step S I 13, the fuel pump executes corresponding instructions. In other words, the fuel pump motor control unit controls the rotating speed of the fuel pump motor according to the detected fuel pressure and the fuel demand control signal. When the fuel pressure is lower than the first predetermined threshold, the fuel pump motor control unit increases the rotating speed of the fuel pump motor. When the fuel pressure reaches the second predetermined threshold, the fuel pump motor control unit stops the fuel pump motor. It should be understood that the first predetermined threshold and the second predetermined threshold can be set according to actual conditions.

It should be noted that, when there is a conflict between the fuel pressure and the fuel demand control signal, the fuel pressure shall prevail. For example, when the engine control unit sends the fuel demand control signal indicating to increase the fuel supply, the fuel pump motor control unit should control the fuel pump to increase the rotating speed so as to supply fuel as required. However, if the fuel pressure detected by the line pressure sensor has reached the second predetermined threshold at this time, the fuel pump motor control unit controls the fuel pump to stop.

After the engine is stopped, the engine control unit stops sending the fuel demand control signal to the fuel pump motor control unit, and the fuel pump motor control unit controls the fuel pump to stop rotating and closes the check valve, thus preventing the fuel from returning.

Any procedure or method described in the flow charts or described in any other way herein may be understood to comprise one or more modules, portions or parts for storing executable codes that realize particular logic functions or procedures. Moreover, advantageous embodiments of the present disclosure comprises other implementations in which the order of execution is different from that which is depicted or discussed, including executing functions in a substantially simultaneous manner or in an opposite order according to the related functions. This should be understood by those skilled in the art which embodiments of the present disclosure belong to.

The logic and/or step described in other manners herein or shown in the flow chart, for example, a particular sequence table of executable instructions for realizing the logical function, may be specifically achieved in any computer readable medium to be used by the instruction execution system, device or equipment (such as the system based on computers, the system comprising processors or other systems capable of obtaining the instruction from the instruction execution system, device and equipment and executing the instruction), or to be used in combination with the instruction execution system, device and equipment. As to the specification, "the computer readable medium" may be any device adaptive for including, storing, communicating, propagating or transferring programs to be used by or in combination with the instruction execution system, device or equipment. More specific examples of the computer readable medium comprise but are not limited to: an electronic connection (an electronic device) with one or more wires, a portable computer enclosure (a magnetic device), a random access memory (RAM), a read only memory (ROM), an erasable programmable read-only memory (EPROM or a flash memory), an optical fiber device and a portable compact disk read-only memory (CDROM). In addition, the computer readable medium may even be a paper or other appropriate medium capable of printing programs thereon, this is because, for example, the paper or other appropriate medium may be optically scanned and then edited, decrypted or processed with other appropriate methods when necessary to obtain the programs in a electric manner, and then the programs may be stored in the computer memories.

It is understood that each part of the present disclosure may be realized by the hardware, software, firmware or their combination. In the above embodiments, a plurality of steps or methods may be realized by the software or firmware stored in the memory and executed by the appropriate instruction execution system. For example, if it is realized by the hardware, likewise in another embodiment, the steps or methods may be realized by one or a combination of the following techniques known in the art: a discrete logic circuit having a logic gate circuit for realizing a logic function of a data signal, an application-specific integrated circuit having an appropriate combination logic gate circuit, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

Those skilled in the art shall understand that all or parts of the steps in the above exemplifying method of the present disclosure may be achieved by commanding the related hardware with programs. The programs may be stored in a computer readable storage medium, and the programs comprise one or a combination of the steps in the method embodiments of the present disclosure when run on a computer.

In addition, each function cell of the embodiments of the present disclosure may be integrated in a processing module, or these cells may be separate physical existence, or two or more cells are integrated in a processing module. The integrated module may be realized in a form of hardware or in a form of software function modules. When the integrated module is realized in a form of software function module and is sold or used as a standalone product, the integrated module may be stored in a computer readable storage medium.

The storage medium mentioned above may be read-only memories, magnetic disks or CD, etc.

Reference throughout this specification to "an embodiment," "some embodiments," "an example," "a specific example," or "some examples," means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. The appearances of the phrases throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.

Claims

What is claimed is:

1. A fuel supply system of an engine of a vehicle, comprising:

a first detecting unit, configured to detect an operating state of the vehicle to generate an operating state signal;

an engine control unit, connected with the first detecting unit and configured to obtain an opening degree of a throttle valve according to the operating state signal when the engine is working, to query a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands to obtain a current fuel demand, and to generate a fuel demand control signal based on the current fuel demand;

a fuel pump, configured to supply fuel to the engine;

a fuel pump motor, configured to drive the fuel pump; and

a fuel pump motor control unit, connected with the fuel pump motor and the engine control unit respectively and configured to control the fuel pump motor according to the fuel demand control signal.

2. The fuel supply system according to claim 1, wherein the fuel pump motor control unit is configured to query a predetermined table indicating a relationship between rotating speeds of the fuel pump motor and the fuel demands to obtain a rotating speed of the fuel pump motor corresponding to the current fuel demand, and to control the fuel pump motor according to the rotating speed of the fuel pump motor.

3. The fuel supply system according to claim 1, wherein a check valve conducted along a direction from the fuel pump to the engine is disposed in a fuel supply line between the engine and the fuel pump.

4. The fuel supply system according to claim 3, further comprising a second detecting unit configured to detect a fuel pressure of a fuel supply line between the check valve and the engine, wherein the second detecting unit is connected with the fuel pump motor control unit, and the fuel pump motor control unit is further configured to control the fuel pump motor according to the fuel pressure and the fuel demand control signal.

5. The fuel supply system according to claim 4, wherein the fuel pump motor control unit is further configured to increase the rotating speed of the fuel pump motor when the fuel pressure is lower than a first predetermined threshold and to stop the fuel pump motor when the fuel pressure reaches a second predetermined threshold, in which the first predetermined threshold is lower than the second predetermined threshold.

6. The fuel supply system according to claim 4, wherein the fuel pump motor control unit is further configured to control the fuel pump motor to rotate and to open the check valve after the vehicle is powered on and before the engine is started; and

the fuel pump motor control unit is further configured to control the fuel pump motor to stop rotating and to close the check valve when the fuel pressure of the fuel supply line between the check valve and the engine reaches the second predetermined threshold.

7. The fuel supply system according to any of claims 1-6, wherein the fuel pump motor is configured as a brushless variable-frequency motor.

8. The fuel supply system according to any of claims 1-7, wherein the first detecting unit communicates with the engine control unit via a CAN network; and

the engine control unit communicates with the fuel pump motor control unit via the CAN network.

9. A fuel supply control method for an engine of a vehicle, comprising:

detecting an operating state of a vehicle to generate an operating state signal when the engine of the vehicle is working;

obtaining an opening degree of a throttle valve according to the operating state signal, querying a predetermined table indicating a relationship between opening degrees of the throttle valve and fuel demands to obtain a current fuel demand, and generating a fuel demand control signal based on the current fuel demand;

controlling a fuel pump motor of the vehicle according to the fuel demand control signal.

10. The fuel supply control method according to claim 9, wherein controlling a fuel pump motor of the vehicle according to the fuel demand control signal further comprises: querying a predetermined table indicating a relationship between rotating speeds of the fuel pump motor and the fuel demands to obtain a rotating speed of the fuel pump motor corresponding to the current fuel demand; and

controlling the fuel pump motor according to the rotating speed of the fuel pump motor.

11. The fuel supply control method according to claim 9, further comprising:

detecting a fuel pressure of a fuel supply line between the engine and the fuel pump;

controlling the rotating speed of the fuel pump motor according to the fuel pressure and the fuel demand control signal.

12. The fuel supply control method according to claim 11, wherein controlling the rotating speed of the fuel pump motor according to the fuel pressure and the fuel demand control signal further comprises:

increasing the rotating speed of the fuel pump motor when the fuel pressure is lower than a first predetermined threshold; and

stopping the fuel pump motor when the fuel pressure reaches a second predetermined threshold, in which the first predetermined threshold is less than the second predetermined threshold.

13. The fuel supply control method according to claim 11, further comprising:

controlling the fuel pump motor to rotate and opening a check valve disposed in the fuel supply line between the engine and the fuel pump after the vehicle is powered on and the engine is started; and

controlling the fuel pump motor to stop rotating and closing the check valve when the fuel pressure reaches the second predetermined threshold.

14. The fuel supply control method according to any of claims 9-13, wherein the fuel pump motor is configured as a brushless variable-frequency motor.