Fuel system leakage detection method and device, fuel system and vehicle

Abstract

The invention provides a fuel system leakage detection method and device, a fuel system and a vehicle. The fuel oil system comprises an oil tank, a carbon canister, an engine and a controller, and the oil tank communicates with an adsorption opening of the carbon canister through a first pipeline; a desorption port of the carbon canister is communicated with an intake manifold of the engine through a second pipeline; an atmosphere port of the carbon tank is communicated with the atmosphere through a third pipeline; a first valve is arranged on the first pipeline, a second valve is arranged on the second pipeline, and a third valve is arranged on the third pipeline; a fourth pipeline is further connected between the intake manifold and the oil tank, and a fourth valve is arranged on the fourth pipeline; the fuel system further comprises a pressure sensor used for detecting the pressure of the fuel tank. And the controller is used for controlling the engine to pressurize the oil tank through the fourth pipeline when the fuel system meets a specified condition, controlling the oil tank to enter a pressure maintaining state when the detected pressure value reaches a specified value, and carrying out leakage detection according to the pressure value detected in the pressure maintaining state.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more particularly to a method, apparatus, fuel system, and vehicle for detecting fuel system leaks. Background Technology

[0002] With the continuous development of the automotive industry, the global car ownership continues to rise, and automobiles have become an indispensable and important means of transportation for people's daily travel and social logistics systems. Although new energy vehicle technology has made rapid progress and gradually achieved large-scale application in recent years, due to factors such as the level of charging and swapping infrastructure construction, vehicle costs, and technological maturity, gasoline-powered vehicles will still occupy the dominant position in the automotive market for a considerable period of time.

[0003] During the operation of gasoline-powered vehicles, the fuel system operates in a closed-loop environment with alternating ventilation. Leaks in this system not only increase fuel evaporation losses and energy waste, but also allow fuel vapors to be directly released into the atmosphere, exacerbating environmental pollution and making it difficult to meet increasingly stringent emission regulations. Furthermore, fuel system leaks can cause fuel odor leaks, abnormal engine operation, and even potential safety hazards, affecting the reliability and safety of the entire vehicle. Therefore, effective and accurate leak diagnosis of automotive fuel systems, and timely detection and identification of potential leaks, are crucial for ensuring vehicle emission compliance, operational safety, and the long-term stable and reliable operation of the fuel system. Summary of the Invention

[0004] In view of this, this application provides a fuel system leak detection method, device, fuel system, and vehicle to effectively detect fuel system leaks and ensure safe vehicle operation.

[0005] The first aspect of this application provides a fuel system, which includes a fuel tank, a charcoal canister, an engine, and a controller; wherein,

[0006] The fuel tank is connected to the adsorption port of the charcoal canister via a first pipeline; the desorption port of the charcoal canister is connected to the intake manifold of the engine via a second pipeline; the atmospheric port of the charcoal canister is connected to the atmosphere via a third pipeline; a first valve is provided on the first pipeline, a second valve is provided on the second pipeline, and a third valve is provided on the third pipeline.

[0007] A fourth pipeline is also connected between the intake manifold and the fuel tank, and a fourth valve is installed on the fourth pipeline; the first valve, the second valve, the third valve and the fourth valve are all controlled by the controller;

[0008] The fuel system also includes a pressure sensor for detecting the pressure in the fuel tank;

[0009] The controller is configured to control the engine to pressurize the fuel tank through the fourth pipeline when the fuel system meets specified conditions, and to control the fuel tank to enter a pressure holding state when the pressure value detected by the pressure sensor reaches a specified value, and to perform leak detection on the fuel system based on the pressure value detected by the pressure sensor in the pressure holding state.

[0010] A second aspect of this application provides a fuel system leak detection method, the method being applied to a controller in any of the fuel systems described in the first aspect of this application, the method comprising:

[0011] When the fuel system meets the specified conditions, the engine is controlled to pressurize the fuel tank through the fourth pipeline;

[0012] When the pressure value detected by the pressure sensor reaches a specified value, the oil tank is controlled to enter a pressure-holding state;

[0013] Leakage detection of the fuel system is performed based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0014] A third aspect of this application provides a fuel system leak detection device, which is applied to a controller in the fuel system described in any of the first aspects of this application. The device includes a control module and a processing module, wherein...

[0015] The control module is used to control the engine to pressurize the fuel tank through the fourth pipeline when the fuel system meets the specified conditions.

[0016] The control module is also used to control the oil tank to enter a pressure-holding state when the pressure value detected by the pressure sensor reaches a specified value;

[0017] The processing module is used to detect leaks in the fuel system based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0018] A fourth aspect of this application provides a vehicle comprising any of the fuel systems described in the first aspect of this application.

[0019] The fuel system leak detection method, device, fuel system, and vehicle provided in this application, by setting up a fuel tank, charcoal canister, engine, and controller, and by installing multiple pipelines and valves between the fuel tank and the charcoal canister, between the charcoal canister and the engine, and between the charcoal canister and the atmosphere, allows for flexible control of the fuel vapor flow direction via valves. Furthermore, by installing a fourth pipeline between the fuel tank and the engine, and by installing a pressure sensor in the fuel system, the fuel tank can be pressurized and maintained under specified conditions. During the pressure maintenance state, the pressure value detected by the pressure sensor enables the detection of the fuel system's sealing performance. This effectively identifies leaks in the fuel tank and pipelines, promptly detects abnormalities, ensures the safe and reliable operation of the fuel system, and improves the overall vehicle operational safety.

[0020] Furthermore, the fuel system leak detection method, device, fuel system, and vehicle provided in this application use the engine as a positive pressure source. The controller can control the opening or closing of each valve according to the operating status of the fuel system, thereby achieving precise control of fuel tank pressurization and pressure maintenance. No additional air pump is required to establish fuel tank pressure, and leak detection can be performed based on this pressure. The structure is simple, the cost is low, and it is easy to integrate.

[0021] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 A schematic diagram of a fuel system embodiment provided in this application;

[0024] Figure 2 A schematic diagram of a second embodiment of the fuel system provided in this application;

[0025] Figure 3 A schematic diagram of the fuel system embodiment three provided in this application;

[0026] Figure 4 A schematic diagram of the fourth embodiment of the fuel system provided in this application;

[0027] Figure 5 A flowchart of Embodiment 1 of the fuel system leak detection method provided in this application;

[0028] Figure 6 A flowchart illustrating a fuel system leak detection method as an exemplary embodiment of this application;

[0029] Figure 7A flowchart of Embodiment 2 of the fuel system leak detection method provided in this application;

[0030] Figure 8 This is a schematic diagram of an embodiment of the fuel system leak detection device provided in this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1: Fuel tank;

[0033] 2: Charcoal canister;

[0034] 3: Engine;

[0035] 4: Controller;

[0036] 51: First pipeline;

[0037] 52: Second pipeline;

[0038] 53: Third pipeline;

[0039] 54: Fourth pipeline;

[0040] 55: Fifth pipeline;

[0041] 56: Sixth pipeline;

[0042] 57: Seventh pipeline;

[0043] 58: Eighth pipeline;

[0044] 61: First valve;

[0045] 62: Second valve;

[0046] 63: Third valve;

[0047] 64: Fourth valve;

[0048] 7: Pressure sensor;

[0049] 8: Air filter;

[0050] 9: Intercooler;

[0051] 10: Venturi valve;

[0052] F1: First three-way valve;

[0053] F2: Second three-way valve. Detailed Implementation

[0054] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0055] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used herein are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0056] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0057] The following specific embodiments are given to illustrate the technical solution of this application in detail.

[0058] Figure 1 This is a schematic diagram of a fuel system embodiment provided in this application. Please refer to... Figure 1 The fuel system provided in this embodiment includes a fuel tank 1, a charcoal canister 2, an engine 3, and a controller 4; wherein,

[0059] The fuel tank 1 is connected to the adsorption port of the charcoal canister 2 via a first pipe 51; the desorption port of the charcoal canister 2 is connected to the intake manifold of the engine 3 via a second pipe 52; the atmospheric port of the charcoal canister 2 is connected to the atmosphere via a third pipe 53; a first valve 61 is provided on the first pipe 51, a second valve 62 is provided on the second pipe 52, and a third valve 63 is provided on the third pipe 53;

[0060] A fourth pipeline 54 is also connected between the intake manifold and the fuel tank 1, and a fourth valve 64 is provided on the fourth pipeline 54; the first valve 61, the second valve 62, the third valve 63, and the fourth valve 64 are all controlled by the controller 4;

[0061] The fuel system also includes a pressure sensor 7 for detecting the pressure of the fuel tank 1;

[0062] The controller 4 is used to control the engine 3 to pressurize the fuel tank 1 through the fourth pipeline 54 when the fuel system meets the specified conditions, and to control the fuel tank 1 to enter the pressure holding state when the pressure value detected by the pressure sensor 7 reaches the specified value, and to perform leakage detection on the fuel system based on the pressure value detected by the pressure sensor 7 in the pressure holding state.

[0063] Specifically, fuel tank 1 stores the fuel required for vehicle operation. Activated carbon canister 2 is filled with activated carbon adsorption material to adsorb and store fuel vapor from the fuel tank, preventing direct emission into the atmosphere to meet emission regulations. Fuel tank 1 and activated carbon canister 2 are connected by a first pipe 51, which is equipped with a first valve 61. This first valve 61 can be a fuel tank isolation valve (FTIV), controlled by controller 4, to control the connection or isolation between fuel tank 1 and activated carbon canister 2. For example, under normal evaporation control conditions, the first valve 61 is open, allowing fuel vapor to enter the activated carbon canister 2 for adsorption.

[0064] For further details, please refer to [link / reference]. Figure 1 The charcoal canister 2 has an adsorption port, a desorption port, and an atmospheric port. Its adsorption port is connected to the fuel tank 1 through the first pipeline 51 to receive fuel vapor evaporated from the fuel tank 1. Its atmospheric port is connected to the outside atmosphere through the third pipeline 53. A third valve 63 is provided on the third pipeline 53, which is controlled by the controller 4 to control whether the charcoal canister 2 is connected to the atmosphere. For example, when the fuel system needs to be ventilated, the third valve 63 can be opened.

[0065] Furthermore, the desorption port of the charcoal canister 2 is connected to the intake manifold of the engine 3 via a second pipe 52, which is used to introduce the adsorbed fuel vapor into the engine for combustion when the engine 3 is running. A second valve 62 is provided on the second pipe 52, which can be a canister purge valve (CPV), controlled by the controller 4, to control whether the fuel vapor in the charcoal canister 2 enters the engine 3 for combustion. For example, it is opened during the desorption condition when the engine 3 is running normally.

[0066] Understandably, engine 3 is used to provide power to the vehicle, and its intake manifold is used to distribute air to the cylinders. In this embodiment, engine 3 acts as a pressure source to provide positive pressure gas to fuel tank 1 through fourth line 54, establishing the detection pressure required for leak diagnosis.

[0067] For further details, please refer to [link / reference]. Figure 1In the fuel system provided in this embodiment, a fourth pipe 54 is connected between the intake manifold and the fuel tank 1. In other words, the fourth pipe 54 is directly connected to the intake manifold of the engine 3 and the fuel tank 1, and is the pressurization passage of this fuel system. In addition, a fourth valve 64 is provided on the fourth pipe 54, which is also controlled by the controller 4 to control the opening and closing of the pressurization passage.

[0068] It should be noted that, in one possible implementation, one end of the fourth pipe 54 can be connected to the intake manifold, and the other end can be connected to the portion of the second pipe 52 located between the adsorption port and the second valve 62. Alternatively, in another possible implementation, one end of the fourth pipe 54 can be connected to the intake manifold, and the other end can be connected to the first pipe 51. In this embodiment, this is not limited.

[0069] Please continue to refer to Figure 1 The fuel system provided in this embodiment also includes a pressure sensor 7, which is used to detect the pressure value inside the fuel tank 1 in real time. It should be noted that the location of the pressure sensor 7 is set according to actual needs, and is not limited in this embodiment. Optionally, in one possible implementation, the pressure sensor can be integrated into the first valve 61, or the pressure sensor 7 can be located in any of the following positions: the fuel tank 1 housing, the fuel filler pipe of the fuel tank 1, or the first pipeline 51.

[0070] Furthermore, controller 4 can be a vehicle electronic control unit (ECU), used to uniformly control the valves of the fuel system and collect and analyze the detection data from the pressure sensors.

[0071] After detailing the structural composition of the fuel system provided in this application, the leakage detection principle of the fuel system provided in this application will be briefly introduced below.

[0072] Specifically, the fuel system leak detection process includes two stages, which will be referred to as the pressure build-up stage and the diagnostic stage for ease of explanation. The pressure build-up stage refers to the process of pressurizing the fuel tank until the pressure reaches a specified value. The diagnostic stage refers to the process of leak detection based on the pressure value under pressure holding conditions after the specified pressure value is reached.

[0073] Specifically, during the pressure build-up phase, when the controller determines that the fuel system meets the specified conditions, the controller controls the engine to pressurize the fuel tank through the fourth pipeline. During the pressurization process, the pressure sensor detects the pressure in the fuel tank in real time and feeds back the detected pressure value to the controller.

[0074] It should be noted that the specified conditions are set according to actual needs, and are not limited in this embodiment. Optionally, in one possible implementation, the specified conditions may include: the engine running time reaches a specified duration, the ambient temperature is within a specified temperature range, the air pressure exceeds a specified pressure, the fuel level in the fuel tank is within a first specified range, and the voltage of the battery supplying power to the fuel system is within a second specified range.

[0075] The specific values ​​of the specified duration, specified temperature range, specified pressure, first specified range, and second specified range are set according to actual needs, and are not limited in this embodiment. In specific implementation, for example, in one possible implementation, the specific values ​​of the specified duration, specified temperature range, specified pressure, first specified range, and second specified range can be set according to regulatory requirements.

[0076] Optionally, in one possible implementation, the specified duration can be 600 seconds, the specified temperature range can be 5℃~35℃, the specified pressure can be 730hPa, the first specified range is 15%~85%, and the second specified range is 11V~16V. In this case, when the engine running time reaches 600 seconds, the ambient temperature is 5℃~35℃, the air pressure is >730hPa, the fuel tank level is between 15%~85%, and the battery voltage supplying the fuel system is 11V~16V, it indicates that the fuel system meets the specified conditions, and the fuel system has the basic conditions for leak detection, and leak detection can begin.

[0077] It should be noted that the two stages of leak detection can be performed either while the vehicle is in motion or while it is parked; this embodiment does not limit this. For example, in one possible implementation, the pressure build-up stage can be performed while the vehicle is in motion, and the diagnostic stage can be performed immediately after the pressure build-up is completed. As another possible implementation, the pressure build-up stage can be performed while the vehicle is parked, and the diagnostic stage can be performed immediately after the pressure build-up is completed. Yet another possible implementation, the pressure build-up stage can be performed while the vehicle is in motion, and then the diagnostic stage can be performed while the vehicle is parked.

[0078] In practice, during the pressure build-up phase, the engine can be controlled to operate in a specified working state. Furthermore, the second and third valves can be controlled to close, while the first and fourth valves can be controlled to open, allowing the gas in the engine intake manifold to enter the fuel tank through the fourth pipeline, thereby pressurizing the fuel tank.

[0079] Furthermore, when the engine is in a specified operating state, the engine's intake manifold is under positive pressure. The specific content of the specified operating state is set according to actual needs, and is not limited in this embodiment. For example, in driving mode, the engine can be controlled to enter idling mode, constant speed cruising mode, or partial load stable operation mode to ensure that the engine's intake manifold pressure is positive, and then the pressure build-up phase begins after the intake manifold pressure is positive. As another example, in parking mode, the engine can be controlled to enter idling mode to ensure that the intake manifold pressure is positive, and then the pressure build-up phase begins after the intake manifold pressure is positive.

[0080] Based on the above description, it can be understood that, in one possible implementation, the controller is specifically used to control the engine to enter a first designated operating state when the vehicle containing the fuel system is in a parked state, and to control the first valve to be in an open state, the second valve to be in a closed state, the third valve to be in a closed state, and the fourth valve to be in an open state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the first designated operating state, the intake manifold of the engine is under positive pressure.

[0081] At this point, for example, the first specified operating state can be idling. Furthermore, after the pressure build-up phase ends, the diagnostic phase can be performed immediately.

[0082] In another possible implementation, the controller is specifically configured to control the first valve to be open, the second valve to be closed, the third valve to be closed, and the fourth valve to be open when the vehicle containing the fuel system is in a driving state and the engine is in a second specified operating state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the second specified operating state, the intake manifold of the engine is under positive pressure.

[0083] At this point, for example, the second designated operating state can be idling, constant speed cruising, or partial load stable operation. In practice, the engine can be actively controlled to enter the second designated operating state, or the pressure build-up process can begin when the engine is determined to be in the second designated operating state, without actively intervening in the engine's operating state, by utilizing the engine's natural operating conditions during vehicle driving.

[0084] It should be noted that during the pressure build-up process, the diagnostic phase can be performed immediately after the pressure build-up is completed.

[0085] As described above, it can be understood that when the controller detects that the pressure value of the oil tank detected by the pressure sensor has reached the specified value, the pressure build-up phase ends, and the controller controls the oil tank to enter the pressure holding state.

[0086] It should be noted that the specific value of the specified value is set according to actual needs, and is not limited in this embodiment. For example, in one possible implementation, the specific value of the specified value can be 5000 Pa.

[0087] In practice, the controller can close the fourth valve to create a relatively enclosed space for the oil tank and related pipelines, so that the oil tank enters a pressure-holding state.

[0088] Specifically, once the fuel tank enters the pressure holding state, the diagnostic phase can begin immediately. At this time, the pressure sensor is still monitoring the pressure value in real time, and the controller performs leak diagnosis on the fuel system based on the pressure detected by the pressure sensor.

[0089] Under normal circumstances, if the fuel system is well sealed, the pressure inside the fuel tank should remain relatively stable under pressure conditions; if there is a leak, the pressure will decrease over time.

[0090] In a specific implementation, for example, in one possible implementation, the controller can calculate the rate of decrease of the pressure value over time, compare the rate of decrease with a preset threshold, and determine that there is no leakage in the fuel system when the rate of decrease is less than or equal to the preset threshold; otherwise, it determines that there is a leakage in the fuel system.

[0091] It should be noted that the specific value of the preset threshold is set according to actual needs, and is not limited in this embodiment. Furthermore, this diagnostic method involves low computational load, making it suitable for online real-time diagnostics of the controller.

[0092] For example, in another possible implementation, a first pressure value when entering the pressure holding state and a second pressure value after the pressure holding state has lasted for a preset time can be recorded. Leak detection can then be performed based on the pressure difference between the first and second pressure values. Specifically, if the pressure difference is less than or equal to a second threshold, it is determined that there is no leak in the fuel system; if the pressure difference is greater than the second threshold, it is determined that there is a leak in the fuel system.

[0093] The specific value of the second threshold is set according to actual needs, and is not limited in this embodiment. Furthermore, this diagnostic method is not sensitive to instantaneous fluctuations and is suitable for scenarios where the pressure signal contains noise.

[0094] For example, in another possible implementation, multiple pressure values ​​can be periodically collected during the pressure holding phase, and then curve fitting can be performed on the multiple pressure values ​​to obtain a pressure change curve. The slope of the pressure change curve is used to characterize the degree of leakage. Thus, if the degree of leakage exceeds a preset threshold, it is determined that there is a leak in the fuel system; otherwise, it is determined that there is no leak in the fuel system.

[0095] Specifically, the preset threshold is set according to actual needs. Furthermore, this diagnostic method can identify minute leaks, improving diagnostic sensitivity.

[0096] As described above, it is understood that the objects of leak detection in this application may include the fuel tank body, refueling hose, refueling hose cap, fuel pump flange sealing the fuel tank, charcoal canister, etc. Leak detection primarily involves checking these components for defects such as holes and gaps, and whether there is a risk of fuel leaking into the atmosphere through these defects.

[0097] The fuel system provided in this embodiment, by setting up a fuel tank, charcoal canister, engine, and controller, and by installing multiple pipelines and valves between the fuel tank and the charcoal canister, between the charcoal canister and the engine, and between the charcoal canister and the atmosphere, allows for flexible control of the fuel vapor flow direction via valves. Furthermore, by installing a fourth pipeline between the fuel tank and the engine, and by installing a pressure sensor in the fuel system, the fuel tank can be pressurized and maintained under specified conditions. During the pressure maintenance state, the pressure value detected by the pressure sensor can be used to detect the fuel system's sealing performance. This effectively identifies fuel tank and pipeline leaks, promptly detects abnormalities, ensures the safe and reliable operation of the fuel system, and improves the overall vehicle operational safety.

[0098] Furthermore, the fuel system provided in this embodiment uses the engine as a positive pressure source. The controller can control the opening or closing of each valve according to the operating status of the fuel system, thereby achieving precise control of fuel tank pressurization and pressure maintenance. No additional air pump is required to establish fuel tank pressure, which can then be used for leak detection. The system is simple in structure, low in cost, and easy to integrate.

[0099] Figure 2 This is a schematic diagram of a second embodiment of the fuel system provided in this application. Figure 3 This is a schematic diagram of a third embodiment of the fuel system provided in this application. Figure 4 This is a schematic diagram of Embodiment 4 of the fuel system provided in this application. Please refer to... Figure 2 , Figure 3 and Figure 4 In one possible implementation, based on the above embodiments, the fuel system provided in this embodiment further includes an air filter 8, an intercooler 9, and a venturi valve 10; wherein,

[0100] The air filter 8 and the intercooler 9 are connected through a fifth pipe 55; the intercooler 9 and the intake manifold are connected through a sixth pipe 56.

[0101] The first port of the Venturi valve 10 is connected to the second pipeline 52; the second port of the Venturi valve 10 is connected to the inlet or outlet of the intercooler 9 through the seventh pipeline 57; and the third port of the Venturi valve 10 is connected to the air filter 8 through the eighth pipeline 58.

[0102] The fourth pipe 54 is used to connect the seventh pipe 57 and the second pipe 52 to the portion of the pipe located between the charcoal canister 2 and the second valve 62, or the fourth pipe 54 is used to connect the seventh pipe 57 and the first pipe 51.

[0103] Specifically, the air filter 8 is used to filter the air entering the engine 3, removing impurities and particulate matter to ensure the intake air quality of the engine 3. In this embodiment, the air filter 8 not only serves as a component of the normal intake of the engine 3, but also provides a low-pressure or reference airflow passage for the venturi valve 10.

[0104] Please continue to refer to Figures 2 to 4 A turbocharger can also be installed between the air filter 8 and the intercooler 9 to pressurize the air entering the engine 3, so that the intake airflow has a higher velocity and pressure.

[0105] Furthermore, the intercooler 9 is used to cool the pressurized intake air to improve intake air density and combustion efficiency. In this embodiment, the intercooler 9 is located between the air filter 8 and the intake manifold of the engine 3, connected to the air filter 8 via the fifth pipe 55, and connected to the intake manifold via the sixth pipe 56.

[0106] It should be noted that in this embodiment, the fuel system is also equipped with a Venturi valve 10. The Venturi valve 10 is a fluid device with a three-way structure, which can generate negative pressure or pressure difference when the gas flows at high speed, and is used to guide or draw gas in other gas passages.

[0107] See Figures 2 to 4 The Venturi valve 10 has a first port, a second port, and a third port. Specifically, the first port of the Venturi valve 10 ( Figure 2 The upper port shown is connected to the second pipeline 52; the second port of the Venturi valve 10 ( Figure 2 The port shown on the left is connected to the inlet or outlet of the intercooler 9 via the seventh pipe 57, and the third port of the venturi valve 10 ( Figure 2 The port shown on the right is connected to the air filter 8 via the eighth pipe 58.

[0108] It should be noted that one end of the seventh pipe 57 is connected to the second port of the Venturi valve 10, and the other end can be connected to either the inlet or outlet of the intercooler 9. For example, in Figure 2 In the example shown, the other end of the seventh pipe 57 is connected to the outlet end of the intercooler 9. For example, in... Figure 3 and Figure 4 In the example shown, the other end of the seventh pipe 57 is connected to the inlet end of the intercooler 9.

[0109] It is understandable that the inlet end of the intercooler 9 refers to the end where air enters, and the outlet end refers to the end where air exits.

[0110] It should be noted that by installing a booster turbine between the air filter 8 and the intercooler 9, a more significant airflow pressure difference can be formed in the intercooler 9 and its connected piping. This booster turbine further enhances the pressure difference effect at the venturi valve 10, making the pressure build-up process more stable and reliable, which helps to shorten the pressure build-up time and improve the accuracy of leak diagnosis during the subsequent pressure holding stage.

[0111] For further details, please refer to [link / reference]. Figure 2 and Figure 3 ,exist Figure 2 and Figure 3 In the example shown, the fourth pipe 54 is used to connect the seventh pipe 57 and the second pipe 52 between the carbon canister 2 and the second valve 62.

[0112] At this time, the fourth pipeline 54 is coordinated with the desorption path of the charcoal canister 2, and the relevant pipelines of the fuel tank 1 and charcoal canister 2 can be pressurized by the airflow pressure difference near the intercooler 9 without directly relying on the intake manifold pressure, thereby realizing the leakage diagnosis of the fuel system.

[0113] For further details, please refer to Figure 4 ,exist Figure 4 In the example shown, the fourth pipe 54 is used to connect the seventh pipe 57 and the first pipe 51. At this time, the pressure difference generated by the Venturi valve 10 can directly act on the pipe between the oil tank 1 and the carbon canister 2, so that the oil tank 1 can obtain the required pressure change during the pressure build-up process.

[0114] See Figures 2 to 4 It is understandable that the first and last ends of the fourth pipeline 54 are equipped with three-way valves, which are connected to the corresponding pipelines.

[0115] The fuel system provided in this embodiment, by incorporating an air filter, intercooler, and venturi valve, and utilizing the airflow pressure difference in the intake system as a pressure source, achieves fuel tank pressure regulation without the need for an additional independent air pump, further reducing system complexity and cost. Simultaneously, the multiple connection methods for the fourth pipeline enhance the flexibility and applicability of the fuel system layout, facilitating its application in different vehicle models and engine structures, and improving the reliability of fuel system leak diagnosis.

[0116] Optional, please continue to refer to Figures 2 to 4 In one possible implementation, the second valve 62, the fourth valve 64, the venturi valve 10, the connecting pipe between the second valve 62 and the venturi valve 10, and the connecting pipe between the fourth valve 64 and the venturi valve 10 are an integrated assembly.

[0117] Specifically, the second valve 62, the fourth valve 64, the venturi valve 10, the connecting pipeline between the second valve 62 and the venturi valve 10, and the connecting pipeline between the fourth valve 64 and the venturi valve 10 are integrated together as a single component.

[0118] In specific implementation, for example, in Figure 2 and Figure 3 In the example shown, the first three-way valve F1 (for ease of explanation, it can be connected to the second valve 62 and the fourth valve 64) can be... Figure 2 The three-way valve shown on the left is referred to as the first three-way valve. The pipeline between the first three-way valve F1 and the second valve 62, the second valve 62, the pipeline between the second valve 62 and the venturi valve 10, the pipeline between the first three-way valve F1 and the fourth valve 64, and the second three-way valve F2 (for ease of explanation, the three-way valve shown on the right is referred to as the second three-way valve) connected to the fourth valve 64 and the venturi valve 10, the pipeline between the second three-way valve F2 and the fourth valve 64, and the pipeline between the second three-way valve F2 and the venturi valve 10 are integrated together to form an integrated component.

[0119] For example, in Figure 4 In the example shown, the second valve 62, the pipeline between the second valve 62 and the venturi valve 10, the venturi valve 10, the pipeline between the venturi valve 10 and the second three-way valve F2, the pipeline between the second three-way valve F2 and the fourth valve 64, and the fourth valve 64 can be integrated together to form an integrated component.

[0120] In this embodiment, by integrating multiple valves and their corresponding connecting pipes, the number of independent pipes and connection interfaces can be reduced, thereby lowering the risk of leakage caused by loose or aging interfaces and improving the sealing reliability of the fuel system. Simultaneously, the integrated component helps shorten the gas flow path, reduce flow resistance, and make the fuel tank pressure regulation response more rapid, improving the stability and accuracy of the leak diagnosis process. Furthermore, integration simplifies the vehicle layout and assembly process, reduces the number of parts, lowers manufacturing and maintenance costs, and improves the overall reliability and consistency of the system.

[0121] Optionally, in one possible implementation, the controller is specifically configured to control the first valve to be open, the second valve to be closed, the third valve to be closed, and the fourth valve to be open when the vehicle containing the fuel system is in a driving state and the engine is in a second specified operating state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the second specified operating state, the intake manifold of the engine is under positive pressure;

[0122] The controller is specifically used to detect leaks in the fuel system when the vehicle containing the fuel system is in a parked state, based on the pressure value detected by the pressure sensor in the pressure-holding state.

[0123] In this embodiment, the pressure building phase is carried out while the vehicle is in motion. After the pressure building is completed, the pressure is maintained, and the vehicle is waited to enter the parking state before the diagnosis phase is carried out while the vehicle is parked.

[0124] Referring to the preceding description, in practice, while the vehicle is in motion, the engine can be actively controlled to enter a second designated operating state. Alternatively, without actively intervening in the engine's operating state, the engine's natural operating conditions during vehicle movement can be utilized, and the pressure build-up process can begin once the engine is determined to be in the second designated operating state.

[0125] For example, with the engine running continuously and the intake manifold pressure ≥120 kPa, the pressure build-up process can begin when the accelerator pedal opening is maintained or continuously increased, without any rapid decrease in accelerator pedal opening, until pressure build-up is complete (i.e., the pressure value reaches the specified value). It should be noted that if deceleration or stopping occurs during the pressure build-up process, the engine can be kept running to maintain the pressure build-up conditions until completion; if the driver stops the engine and disconnects power during the pressure build-up process, the diagnostic process will exit.

[0126] It should be noted that after the pressure build-up is completed, you can wait for the vehicle to enter a parking state before starting the diagnostic phase.

[0127] In practice, if the driver loses power or leaves the vehicle during the diagnostic phase, the diagnostic phase will continue.

[0128] It should be noted that in this embodiment, the pressure build-up phase is performed during driving. After the pressure build-up is completed, the diagnostic phase is not started immediately. Instead, the diagnostic phase begins only after the vehicle has come to a complete stop. If the pressure value fluctuates and falls below a specified value during the period between the end of the pressure build-up phase and the start of the diagnostic phase, the pressure build-up process can be repeated when the engine's operating conditions meet the pressure build-up conditions (i.e., when the engine's intake manifold is under positive pressure), so that the pressure value reaches the specified value at the start of the diagnostic phase.

[0129] When the vehicle is parked, the pressure value can be checked first to see if it has reached the specified value. If it has, the diagnostic phase can be started directly. If not, the pressure build-up process can be executed again (for example, the engine can be controlled to enter the first specified working state), and the diagnostic phase can be started immediately after the pressure build-up is completed.

[0130] It should be noted that in this embodiment, the diagnostic phase is performed while the vehicle is stationary. At this time, the vehicle is no longer moving, and the fuel level and vapor space in the fuel tank are in a relatively stable state. This effectively avoids disturbances to the monitored pressure values ​​caused by fluctuations in the fuel level. Consequently, the pressure values ​​collected by the pressure sensor are more stable and reliable, which helps improve the accuracy of pressure change determination during leak diagnosis and further enhances the reliability of fuel system leak diagnosis.

[0131] The fuel system provided in this embodiment builds pressure while the vehicle is in motion and performs diagnostics while the vehicle is stationary. It fully utilizes the natural positive pressure condition of the engine intake manifold during vehicle operation to actively build pressure in the fuel tank. This eliminates the need for additional pressure-building operations, thus completing pressure preparation without affecting normal vehicle use. After the vehicle stops, leak diagnosis is performed based on the stable pressure state, effectively avoiding interference with vehicle performance and user driving experience during the diagnostic process. This reduces system energy consumption and control complexity, and improves the reliability of leak diagnosis and user experience. Furthermore, when performing diagnostics while the vehicle is stationary, the fuel tank is in a stable state, avoiding the impact of fuel tank fluctuations on pressure values, further enhancing diagnostic reliability.

[0132] Corresponding to the aforementioned embodiment of a fuel system, this application also provides an embodiment of a fuel system leak detection method, which is described below.

[0133] Figure 5 This is a flowchart of an embodiment of the fuel system leak detection method provided in this application. Please refer to... Figure 5The method provided in this embodiment is applied to a controller in any of the fuel systems described in the first aspect of this application. The method may include:

[0134] S501. When the fuel system meets the specified conditions, control the engine to pressurize the fuel tank through the fourth pipeline.

[0135] S502. When the pressure value detected by the pressure sensor reaches the specified value, control the oil tank to enter the pressure holding state.

[0136] S503. The fuel system is leak-detected based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0137] The specific implementation principles and processes of steps S501 to S503 can be found in the descriptions in the previous embodiments, and will not be repeated here.

[0138] Figure 6 This is a flowchart illustrating a fuel system leak detection method as an exemplary embodiment of this application. Please refer to... Figure 6 In one possible implementation, the fuel system leak detection method provided in this embodiment may include:

[0139] S601. Monitor whether the fuel system meets the specified conditions. If so, proceed to step S602.

[0140] S602. Control the engine to enter a specified working state, and control the first valve to be in the open state, the second valve to be in the closed state, the third valve to be in the closed state, and the fourth valve to be in the open state, so that the engine supplies gas to the fuel tank through the fourth pipeline.

[0141] S603. Determine whether the pressure value detected by the pressure sensor has reached the specified value. If so, proceed to step S604.

[0142] S604. Control the fourth valve to be in the closed state so that the oil tank enters the pressure holding state.

[0143] S605. The fuel system is leak-detected based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0144] The specific implementation principles and processes of steps S601 to S605 can be found in the descriptions in the previous embodiments, and will not be repeated here.

[0145] Optionally, in one possible implementation, the control engine pressurizes the fuel tank via a fourth line, including:

[0146] When the vehicle containing the fuel system is in a parked state, the engine is controlled to enter a first designated operating state, and the first valve is controlled to be in an open state, the second valve to be in a closed state, the third valve to be in a closed state, and the fourth valve to be in an open state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the first designated operating state, the intake manifold of the engine is under positive pressure.

[0147] Optionally, in one possible implementation, the control engine pressurizes the fuel tank via a fourth line, including:

[0148] When the vehicle containing the fuel system is in motion and the engine is in a second designated operating state, the first valve is controlled to be in the open state, the second valve to be in the closed state, the third valve to be in the closed state, and the fourth valve to be in the open state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the second designated operating state, the intake manifold of the engine is under positive pressure.

[0149] Optionally, in one possible implementation, the step of detecting a leak in the fuel system based on the pressure value detected by the pressure sensor under the pressure-holding state includes:

[0150] When the vehicle containing the fuel system is parked, the fuel system is leak-detected based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0151] For details on the specific implementation principles and processes of this step, please refer to the descriptions in the previous embodiments, which will not be repeated here.

[0152] Figure 7 For the flowchart of Embodiment 2 of the fuel system leak detection method provided in this application, please refer to... Figure 7 In one possible implementation, the method may include:

[0153] S701. When the vehicle containing the fuel system is in a driving state, and when the fuel system meets specified conditions and the engine is in a second specified operating state, control the first valve to be in an open state, the second valve to be in a closed state, the third valve to be in a closed state, and the fourth valve to be in an open state, so that the engine supplies gas to the fuel tank through the fourth pipeline.

[0154] S702. When the pressure value detected by the pressure sensor reaches the specified value, the fourth valve is closed to control the oil tank to enter the pressure holding state.

[0155] S703. When the vehicle containing the fuel system is in a parked state, leak detection is performed on the fuel system based on the pressure value detected by the pressure sensor in the pressure-holding state.

[0156] Referring to the preceding description, in one possible implementation, if the pressure value drops below a specified value during the pressure holding process, the pressure building process can be repeated once the engine meets the pressure building conditions, so that the pressure value in the fuel tank is maintained above the specified value.

[0157] In addition, when the vehicle enters the parking state, it can first determine whether the pressure value is above the specified value. If so, the diagnosis stage can be carried out directly. If not, the pressure building process can be carried out again, and then the diagnosis stage can be entered immediately after the pressure building is completed.

[0158] The method provided in this embodiment performs pressure building in the driving state and diagnosis in the parking state, which can improve the user experience.

[0159] Corresponding to the aforementioned embodiment of a fuel system leak detection method, this embodiment also provides a fuel system leak detection device. The fuel system leak detection device provided in this application will be described below.

[0160] Figure 8 This is a schematic diagram of Embodiment 1 of the fuel system leak detection device provided in this application. Please refer to... Figure 8 The fuel system leak detection device provided in this embodiment is applied to the controller in the fuel system provided in the first aspect of this application. The device includes a control module 810 and a processing module 820, wherein...

[0161] The control module 810 is used to control the engine to pressurize the fuel tank through the fourth pipeline when the fuel system meets the specified conditions.

[0162] The control module 810 is also used to control the oil tank to enter a pressure-holding state when the pressure value detected by the pressure sensor reaches a specified value;

[0163] The processing module 820 is used to perform leak detection on the fuel system based on the pressure value detected by the pressure sensor under the pressure-holding state.

[0164] The apparatus provided in this embodiment can be used to perform... Figure 5 The steps of the method embodiment shown are similar in principle and process, and will not be repeated here.

[0165] This application also provides a vehicle that includes the fuel system described in any of the first aspects of this application.

[0166] The specific implementation process of the functions and roles of each unit in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0167] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0168] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A fuel system characterised in that, The fuel system includes a fuel tank, a charcoal canister, an engine, and a controller; wherein, The fuel tank is connected to the adsorption port of the charcoal canister via a first pipeline; the desorption port of the charcoal canister is connected to the intake manifold of the engine via a second pipeline; the atmospheric port of the charcoal canister is connected to the atmosphere via a third pipeline; a first valve is provided on the first pipeline, a second valve is provided on the second pipeline, and a third valve is provided on the third pipeline. A fourth pipeline is also connected between the intake manifold and the fuel tank, and a fourth valve is installed on the fourth pipeline; the first valve, the second valve, the third valve and the fourth valve are all controlled by the controller; The fuel system also includes a pressure sensor for detecting the pressure in the fuel tank; The controller is configured to control the engine to pressurize the fuel tank through the fourth pipeline when the fuel system meets specified conditions, and to control the fuel tank to enter a pressure holding state when the pressure value detected by the pressure sensor reaches a specified value, and to perform leak detection on the fuel system based on the pressure value detected by the pressure sensor in the pressure holding state.

2. The fuel system of claim 1, wherein The fuel system also includes an air filter, an intercooler, and a venturi valve; wherein... The air filter is connected to the intercooler via a fifth pipe; the intercooler is connected to the intake manifold via a sixth pipe; The first port of the Venturi valve is connected to the second pipeline; the second port of the Venturi valve is connected to the inlet or outlet of the intercooler through the seventh pipeline; and the third port of the Venturi valve is connected to the air filter through the eighth pipeline. The fourth pipeline is used to connect the seventh pipeline and the portion of the second pipeline located between the charcoal canister and the second valve, or the fourth pipeline is used to connect the seventh pipeline and the first pipeline.

3. The fuel system according to claim 1, characterized in that, The pressure sensor is integrated into the first valve; or, The pressure sensor is located at any of the following positions: the tank body of the fuel tank, the fuel filling pipe of the fuel tank, or the first pipeline.

4. The fuel system according to claim 2, characterized in that, The second valve, the fourth valve, the venturi valve, the connecting pipeline between the second valve and the venturi valve, and the connecting pipeline between the fourth valve and the venturi valve are integrated into a single component.

5. The fuel system according to claim 1, characterized in that, The controller is specifically used to control the engine to enter a first designated operating state when the vehicle containing the fuel system is in a parked state, and to control the first valve to be in an open state, the second valve to be in a closed state, the third valve to be in a closed state, and the fourth valve to be in an open state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the first designated operating state, the intake manifold of the engine is under positive pressure.

6. The fuel system according to claim 1, characterized in that, The controller is specifically configured to control the first valve to be open, the second valve to be closed, the third valve to be closed, and the fourth valve to be open when the vehicle containing the fuel system is in a driving state and the engine is in a second specified operating state, so that the engine supplies gas to the fuel tank through the fourth pipeline; wherein, when the engine is in the second specified operating state, the intake manifold of the engine is under positive pressure.

7. The fuel system according to claim 6, characterized in that, The controller is specifically used to detect leaks in the fuel system when the vehicle containing the fuel system is in a parked state, based on the pressure value detected by the pressure sensor in the pressure-holding state.

8. A method for detecting fuel system leaks, characterized in that, The method is applied to a controller in the fuel system according to any one of claims 1 to 7, the method comprising: When the fuel system meets the specified conditions, the engine is controlled to pressurize the fuel tank through the fourth pipeline; When the pressure value detected by the pressure sensor reaches a specified value, the oil tank is controlled to enter a pressure-holding state; Leakage detection of the fuel system is performed based on the pressure value detected by the pressure sensor under the pressure-holding state.

9. A fuel system leak detection device, characterized in that, The device is applied to a controller in the fuel system according to any one of claims 1 to 7, the device comprising a control module and a processing module, wherein... The control module is used to control the engine to pressurize the fuel tank through the fourth pipeline when the fuel system meets the specified conditions. The control module is also used to control the oil tank to enter a pressure-holding state when the pressure value detected by the pressure sensor reaches a specified value; The processing module is used to detect leaks in the fuel system based on the pressure value detected by the pressure sensor under the pressure-holding state.

10. A vehicle, characterized in that, The vehicle includes the fuel system according to any one of claims 1 to 7.

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