Engine oil supply system control method and device and engine oil supply system

Abstract

The invention discloses an engine oil supply system control method and device and an engine oil supply system. The method comprises the steps that first fuel oil pressure between a low-pressure oil way and a high-pressure oil way is obtained through a low-pressure sensor, and the actual oil supply amount input into the high-pressure oil way is determined; the oil outlet quantity of a high-pressure oil rail in the high-pressure oil way is obtained; inputting the actual fuel supply quantity and the actual fuel outlet quantity into a preset rail pressure calculation model to determine second fuel pressure of the high-pressure fuel rail; and the actual oil supply amount input into the high-pressure oil way is adjusted according to the second fuel oil pressure. In the process of adjusting the oil supply amount, the actual oil supply amount input into the high-pressure oil way is determined by detecting the first fuel oil pressure between the low-pressure oil way and the high-pressure oil way, and then the second fuel oil pressure of the high-pressure oil rail is determined according to the actual oil supply amount and the oil outlet amount of the high-pressure oil rail; and the second fuel pressure in the high-pressure fuel rail is obtained, so that the cost for adjusting the fuel supply amount is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to an engine fuel supply system control method, device, and engine fuel supply system. Background Technology

[0002] Modern car engines generally use high-pressure direct injection technology. Compared with traditional naturally aspirated engines, high-pressure direct injection technology injects fuel directly into the cylinder, achieving more precise fuel control and higher combustion efficiency, thereby significantly improving engine power output and fuel economy.

[0003] Direct injection engines typically include a low-pressure fuel line and a high-pressure fuel line. The high-pressure fuel line contains a high-pressure fuel rail equipped with a rail pressure sensor. This sensor accurately detects the fuel pressure within the high-pressure fuel rail and adjusts the fuel supply between the high-pressure and low-pressure lines accordingly. However, the rail pressure sensor, being a precision pressure sensing device, is expensive, resulting in excessively high costs for the fuel supply adjustment process. Summary of the Invention

[0004] The main objective of this invention is to provide a method, device, and system for controlling an engine fuel supply system, which aims to solve the problem of high cost in the prior art of using rail pressure sensors to detect fuel pressure in the high-pressure fuel rail.

[0005] To achieve the above objectives, the present invention provides a method for controlling an engine fuel supply system, the engine fuel supply system comprising: a low-pressure fuel line, a high-pressure fuel line, and a low-pressure sensor disposed between the high-pressure fuel line and the low-pressure fuel line; The method includes: The first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit is obtained through the low-pressure sensor; The actual fuel supply to the high-pressure fuel circuit is determined based on the first fuel pressure. Obtain the oil output of the high-pressure oil rail in the high-pressure oil circuit; The actual fuel supply and the fuel output are input into a preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The actual fuel supply to the high-pressure fuel circuit is adjusted according to the second fuel pressure.

[0006] Optionally, determining the actual fuel supply to the high-pressure fuel circuit based on the first fuel pressure includes: Obtain the pump speed of the high-pressure oil pump in the high-pressure oil circuit; Obtain the theoretical oil supply quantity input to the high-pressure oil circuit; The correction factor for the theoretical fuel supply is determined by the first fuel pressure and the fuel pump speed. The actual fuel supply is obtained by correcting the theoretical fuel supply based on the correction factor.

[0007] Optionally, obtaining the theoretical oil supply to the high-pressure oil circuit includes: The signal duty cycle for acquiring the control signal from the fuel metering valve; The theoretical oil supply to the high-pressure oil circuit is determined based on the oil pump speed, the signal duty cycle, and the first mapping relationship, whereby the first mapping relationship is the correspondence between the oil pump speed, the signal duty cycle of the control signal, and the theoretical oil supply.

[0008] Optionally, adjusting the actual fuel supply to the high-pressure fuel circuit based on the second fuel pressure includes: Obtain the target fuel pressure of the high-pressure fuel rail; The signal duty cycle of the control signal for adjusting the fuel metering valve is adjusted according to the target fuel pressure and the second fuel pressure. The actual oil supply to the high-pressure oil circuit is adjusted according to the adjusted control signal.

[0009] Optionally, obtaining the target fuel pressure of the high-pressure fuel rail includes: Obtain engine speed and engine load; The target fuel pressure of the high-pressure fuel rail is determined based on the engine speed, the engine load, and a second mapping relationship, whereby the second mapping relationship is the correspondence between engine speed, engine load, and the target fuel pressure of the high-pressure fuel rail.

[0010] Optionally, determining the target fuel pressure of the high-pressure fuel rail based on the engine speed, the engine load, and the second mapping relationship further includes: Obtain the current temperature of the high-pressure oil rail; The corrected second mapping relationship is obtained by correcting the second mapping relationship based on the current temperature; The target fuel pressure of the high-pressure fuel rail is determined based on the engine speed, the engine load, and the corrected second mapping relationship.

[0011] Optionally, after obtaining the first fuel pressure between the low-pressure fuel line and the high-pressure fuel line through the low-pressure sensor, the method further includes: When the first fuel pressure is less than a preset pressure threshold, a first fault signal is output, which is used to indicate that the low-pressure oil circuit is in a fault state.

[0012] Optionally, the step of obtaining the first fuel pressure between the low-pressure fuel circuit and the high-pressure fuel circuit through the low-pressure sensor further includes: While the first fuel pressure is not less than a preset pressure threshold, the second fuel pressure is continuously acquired and the adjustment time of the second fuel pressure is recorded. If the second fuel pressure is not adjusted to the target fuel pressure when the adjustment time reaches the preset time, a second fault signal is output. The second fault signal is used to indicate that the high-pressure oil circuit is in a fault state.

[0013] In addition, to achieve the above objectives, the present invention also proposes an engine fuel supply system control device, wherein the engine fuel supply system includes: a low-pressure fuel line, a high-pressure fuel line, and a low-pressure sensor disposed between the high-pressure fuel line and the low-pressure fuel line. The device includes: The pressure acquisition module is used to acquire the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor; The fuel supply quantity determination module is used to determine the actual fuel supply quantity input to the high-pressure fuel circuit based on the first fuel pressure. The oil output acquisition module is used to acquire the oil output of the high-pressure oil rail in the high-pressure oil circuit; The pressure determination module is used to input the actual fuel supply and the fuel output into a preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The fuel supply control module is used to adjust the actual fuel supply to the high-pressure fuel circuit according to the second fuel pressure.

[0014] Furthermore, to achieve the above objectives, the present invention also proposes an engine fuel supply system, comprising: The low-pressure oil circuit includes a low-pressure oil pump and a fuel filter connected by an oil pipe. The high-pressure oil circuit includes a high-pressure oil pump, a high-pressure oil rail, and an injector connected by oil pipes. A fuel metering valve is installed on the oil pipe between the fuel filter and the high-pressure fuel pump; A low-pressure sensor is installed on the oil pipe between the fuel filter and the fuel metering valve; An electronic control unit is connected to the low-pressure sensor and the fuel metering valve in the high-pressure oil circuit. The electronic control unit is used to execute the engine fuel supply system control method described above.

[0015] This invention discloses a method, device, and system for controlling an engine fuel supply system. The method acquires a first fuel pressure between a low-pressure fuel line and a high-pressure fuel line using a low-pressure sensor; determines the actual fuel supply quantity to the high-pressure fuel line based on the first fuel pressure; acquires the fuel output quantity from the high-pressure fuel rail within the high-pressure fuel line; inputs the actual fuel supply quantity and the fuel output quantity into a preset rail pressure calculation model to determine a second fuel pressure on the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail; and adjusts the actual fuel supply quantity to the high-pressure fuel line based on the second fuel pressure. In the process of adjusting the fuel supply quantity, this invention determines the actual fuel supply quantity to the high-pressure fuel line by detecting the first fuel pressure between the low-pressure and high-pressure fuel lines, and then determines the second fuel pressure on the high-pressure fuel rail based on the actual fuel supply quantity and the fuel output quantity from the high-pressure fuel rail. This allows for the acquisition of the second fuel pressure within the high-pressure fuel rail without the need for a rail pressure sensor, effectively reducing the cost of fuel supply quantity adjustment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an engine fuel supply system in the prior art; Figure 2 This is a flowchart illustrating the first embodiment of the engine fuel supply system control method of the present invention; Figure 3 This is a flowchart illustrating the second embodiment of the engine fuel supply system control method of the present invention; Figure 4 This is a flowchart illustrating the third embodiment of the engine fuel supply system control method of the present invention; Figure 5 This is a schematic diagram of the first process of the fourth embodiment of the engine fuel supply system control method of the present invention; Figure 6 This is a second flowchart illustrating the fourth embodiment of the engine fuel supply system control method of the present invention; Figure 7 This is a structural block diagram of the first embodiment of the engine fuel supply system control device of the present invention; Figure 8 This is a first structural schematic diagram of the engine fuel supply system of the present invention; Figure 9 This is a schematic diagram of the second structure of the engine fuel supply system of the present invention; Figure 10 This is a schematic diagram of the structure for adjusting the fuel metering valve in the engine fuel supply system of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] It should be noted that, referring to Figure 1 , Figure 1 This is a schematic diagram of the structure of an engine fuel supply system in the prior art. Figure 1 In a direct injection engine, the fuel supply system typically includes a low-pressure fuel line 1 and a high-pressure fuel line 2. The low-pressure fuel line 1 includes a low-pressure fuel pump 11 and a fuel filter 12. The low-pressure fuel pump 11 is located in the fuel tank and is connected to the fuel filter 12 via a fuel line. The fuel filter 12 is connected to the high-pressure fuel line 2 via a fuel line. The high-pressure fuel line 2 includes a high-pressure fuel pump 21, a high-pressure fuel rail 22, and an injector 23, all connected via fuel lines. The high-pressure fuel pump 21 is also connected to the low-pressure fuel line 1 via a fuel line, and a rail pressure sensor is installed in the high-pressure fuel rail 22 to detect the fuel pressure within the high-pressure fuel rail. Direct injection engines can be used in diesel or gasoline engines. The high-pressure fuel pump can be a mechanical high-pressure fuel pump driven by the engine camshaft or an electronic high-pressure fuel pump driven by an electric motor.

[0020] A fuel metering valve 3 is installed on the oil pipe between the high-pressure oil circuit and the low-pressure oil circuit to control the amount of fuel input from the low-pressure oil circuit to the high-pressure oil circuit. The high-pressure oil pump 21 is usually a radial piston pump, and each fuel supply stroke includes an intake stroke and a compression stroke.

[0021] The suction stroke is as follows: the plunger moves downward due to the action of the driving cam, the pump chamber volume increases, negative pressure is generated, the fuel metering valve opens, and low-pressure fuel is sucked into the pump chamber of the high-pressure fuel pump 21.

[0022] The compression stroke is as follows: the plunger drives the cam to move upward. In the initial stage of the compression stroke, the pressure inside the pump chamber of the high-pressure fuel pump 21 is low, the fuel metering valve 3 is not yet closed, and some fuel is squeezed back into the low-pressure fuel circuit; at this time, no fuel is supplied to the high-pressure fuel rail 22. With the fuel metering valve 3 closed, the pump chamber of the high-pressure fuel pump 21 becomes a closed space. As the plunger continues to move upward, the fuel inside the pump chamber of the high-pressure fuel pump 21 is compressed, and the pressure rises sharply until it exceeds the rail pressure. At this point, the high-pressure delivery valve located at the outlet of the high-pressure fuel pump is opened, and high-pressure fuel is pumped into the high-pressure fuel rail 22. Until the plunger reaches top dead center and moves downward, the pump chamber pressure drops, the high-pressure delivery valve closes, and the fuel metering valve opens under the action of the spring, initiating the intake of the next cycle.

[0023] The engine fuel supply system operates as follows: When the vehicle is powered on, the low-pressure fuel pump located in the fuel tank starts, drawing fuel from the tank and sending it through fuel lines to the fuel filter. After being filtered by the fuel filter, the fuel enters the high-pressure fuel pump. The fuel is then pressurized by the high-pressure pump, becoming high-pressure fuel. This high-pressure fuel is then delivered to the high-pressure fuel rail for storage. The high-pressure fuel rail is connected to the injectors, and the injectors are precisely controlled according to the firing order to directly inject high-pressure fuel into the combustion chambers of each cylinder.

[0024] During engine fuel supply system operation, the fuel pressure within the high-pressure fuel rail affects the fuel injection quantity from the injectors. To accurately control the injectors, a rail pressure sensor located within the high-pressure fuel rail is needed to detect the fuel pressure. However, the rail pressure sensor, being a precision component, is costly, leading to excessively high costs associated with fuel supply adjustment. Furthermore, if the rail pressure sensor fails or malfunctions, it can cause vehicle limpness and severely limit engine performance.

[0025] To address the above problems, embodiments of the present invention provide an engine fuel supply system control method, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the engine fuel supply system control method of the present invention.

[0026] In this embodiment, the engine fuel supply system control method includes the following steps: Step S10: Obtain the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor.

[0027] It should be noted that the execution subject of the method in this embodiment can be the engine fuel supply system or the electronic control unit within the engine fuel supply system. This electronic control unit can control the fuel injection quantity of the engine fuel supply system according to the fuel supply demand during vehicle operation. The following description uses the aforementioned electronic control unit as the execution subject to illustrate this embodiment and the following embodiments.

[0028] It is understandable that the first fuel pressure is the fuel pressure during the process of delivering fuel from the low-pressure fuel line to the high-pressure fuel line. This first fuel pressure is not pressurized by the high-pressure fuel pump. The low-pressure sensor is a sensor installed between the high-pressure and low-pressure fuel lines to detect the first fuel pressure.

[0029] In practice, the low-pressure sensor can collect the initial fuel pressure between the fuel filter and the high-pressure fuel pump during the fuel supply process of the engine fuel supply system, and then transmit the fuel pressure to the electronic control unit.

[0030] Step S20: Determine the actual fuel supply to the high-pressure oil circuit based on the first fuel pressure.

[0031] It should be noted that the actual fuel supply is the amount of fuel supplied from the low-pressure oil circuit to the high-pressure oil pump during the operation of the engine fuel supply system, that is, the amount of fuel received by the high-pressure oil pump.

[0032] In this embodiment, the oil pipe between the low-pressure oil circuit and the high-pressure oil circuit is a sealed oil pipe with a fixed capacity. When different types of fuel are input, the initial fuel pressure in the oil pipe between the low-pressure and high-pressure oil circuits will differ. There is a certain mapping relationship between the actual fuel supply and the initial fuel pressure in the oil pipe between the low-pressure and high-pressure oil circuits. For example, if the amount of fuel previously in the oil pipe is fixed, a smaller amount of fuel output from the low-pressure oil circuit will result in a lower initial fuel pressure; conversely, a larger amount of fuel output from the low-pressure oil circuit will result in a higher initial fuel pressure.

[0033] In practice, once the first fuel pressure is obtained, the amount of fuel in the oil pipe can be determined based on the relationship between the first fuel pressure and the fuel quantity in the pipe, thereby determining the actual fuel supply from the low-pressure oil circuit to the high-pressure oil circuit.

[0034] Step S30: Obtain the oil output of the high-pressure oil rail in the high-pressure oil circuit.

[0035] It should be understood that the fuel output of the high-pressure fuel rail is the amount of fuel supplied to the injectors during vehicle operation. The high-pressure fuel rail typically stores a certain amount of fuel. After the vehicle starts, the injectors inject fuel into the engine cylinders. Since the high-pressure fuel rail is connected to the injectors, the fuel output of the high-pressure fuel rail is the same as the fuel injection volume of the injectors.

[0036] In practice, the fuel output of the high-pressure fuel rail can be determined by the amount of fuel required by the engine, i.e., the fuel output of the high-pressure fuel rail is determined based on the vehicle's driving state. For example, when the vehicle is accelerating, the opening of the accelerator pedal increases, and the amount of fuel required by the engine increases, which means the fuel output of the high-pressure fuel rail increases.

[0037] Step S40: Input the actual fuel supply and the fuel output into the preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail.

[0038] It should be noted that the second fuel pressure refers to the fuel pressure within the high-pressure fuel rail. This second fuel pressure affects the amount of fuel injected by the injectors, thus impacting vehicle operation. For example, if the second fuel pressure is low, the amount of fuel stored in the high-pressure fuel rail is low. If the vehicle needs to accelerate at this time, insufficient fuel will be delivered to the injectors, preventing the vehicle from accelerating properly. Therefore, monitoring the second fuel pressure is crucial during vehicle operation.

[0039] It should be understood that the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The mass balance principle states that in a confined space where no medium can be generated or consumed, the mass of the medium within the confined space is only affected by the mass of the medium input into the confined space and the mass of the medium output from the confined space. In this embodiment, the high-pressure fuel rail is a confined rail, and the amount of fuel within it is only affected by the actual fuel supply to the high-pressure fuel rail and the fuel output from the high-pressure fuel rail. When the actual fuel supply is greater than the fuel output, the second fuel pressure within the high-pressure fuel rail increases; when the actual fuel supply is less than the fuel output, the second fuel pressure within the high-pressure fuel rail decreases.

[0040] In practice, the actual fuel supply and output can be input into the preset rail pressure calculation model. The preset rail pressure model can output the second fuel pressure in the high-pressure fuel rail through internal calculation.

[0041] Step S50: Adjust the actual fuel supply to the high-pressure oil circuit according to the second fuel pressure.

[0042] It should be understood that the fuel in the high-pressure fuel rail is supplied by the low-pressure fuel circuit and the high-pressure fuel pump. If the secondary fuel pressure in the high-pressure fuel rail is too high or too low, the actual fuel supply to the high-pressure fuel circuit can be adjusted to regulate the secondary fuel pressure in the high-pressure fuel rail, thus responding to changes in the vehicle's operating state. For example, when the vehicle is accelerating and the secondary fuel pressure is low, the actual fuel supply from the low-pressure fuel circuit can be increased, allowing more fuel to be supplied to the high-pressure fuel rail. This increases the amount of fuel in the high-pressure fuel rail, raising the secondary fuel pressure, which in turn allows the injectors to spray more fuel to respond to vehicle acceleration.

[0043] In practice, when the vehicle's operating status changes, the actual fuel supply output of the low-pressure fuel circuit can be adjusted according to the second fuel pressure to respond to changes in the vehicle's operating status.

[0044] This embodiment describes a method for controlling an engine fuel supply system. The method acquires a first fuel pressure between a low-pressure fuel line and a high-pressure fuel line using a low-pressure sensor; determines the actual fuel supply quantity to the high-pressure fuel line based on the first fuel pressure; acquires the fuel output quantity from the high-pressure fuel rail within the high-pressure fuel line; inputs the actual fuel supply quantity and the fuel output quantity into a preset rail pressure calculation model to determine a second fuel pressure on the high-pressure fuel rail; and adjusts the actual fuel supply quantity to the high-pressure fuel line based on the second fuel pressure. In this embodiment, during the adjustment of the fuel supply quantity, the actual fuel supply quantity to the high-pressure fuel line is determined by detecting the first fuel pressure between the low-pressure and high-pressure fuel lines. Then, the second fuel pressure on the high-pressure fuel rail is determined based on the actual fuel supply quantity and the fuel output quantity from the high-pressure fuel rail. This method obtains the second fuel pressure within the high-pressure fuel rail without the need for a rail pressure sensor, effectively reducing the cost of fuel supply quantity adjustment.

[0045] Based on the first embodiment described above, a second embodiment of the engine fuel supply system control method of this application is proposed. (See reference...) Figure 3 , Figure 3 This is a flowchart illustrating the second embodiment of the engine fuel supply system control method of the present invention.

[0046] In this embodiment, step S20 includes: Step S201: Obtain the pump speed of the high-pressure oil pump in the high-pressure oil circuit.

[0047] It should be understood that the actual fuel supply in the high-pressure fuel circuit is related to the pump speed of the high-pressure fuel pump. With other parameters remaining the same, the lower the pump speed, the lower the amount of fuel pressurized by the high-pressure fuel pump; conversely, the higher the pump speed, the higher the amount of fuel pressurized. If the low-pressure fuel circuit input is pre-set to require the high-pressure fuel pump to operate at a target speed, and the high-pressure fuel pump speed is not the pre-set target speed, then the amount of fuel received by the high-pressure fuel pump will not be the same as the amount input from the low-pressure fuel circuit. In this case, the theoretical fuel supply to the high-pressure fuel circuit needs to be corrected to obtain the actual fuel supply from the low-pressure fuel circuit to the high-pressure fuel circuit.

[0048] In practice, the pump speed of the high-pressure oil pump can be detected by sensors or by detecting the engine speed. The pump speed of the high-pressure oil pump can be determined based on the ratio between the engine speed and the pump speed of the high-pressure oil pump.

[0049] Step S202: Obtain the theoretical oil supply quantity input to the high-pressure oil circuit.

[0050] It should be noted that the theoretical fuel supply to the high-pressure oil circuit is the theoretical amount of fuel received by the high-pressure oil circuit when the components in the low-pressure and high-pressure oil circuits are working. The theoretical fuel supply is affected by the operating parameters of the oil pump.

[0051] In practice, the theoretical oil supply to the high-pressure oil circuit can be determined by the specific operating parameters of the oil pump, such as the power and speed of the low-pressure oil pump.

[0052] Step S203: Determine the correction coefficient for the theoretical fuel supply based on the first fuel pressure and the oil pump speed.

[0053] It should be understood that during the actual fuel output process of the low-pressure fuel circuit, due to the fluctuation of fuel pressure in the fuel line of the low-pressure fuel circuit, the fuel cannot completely fill the plunger chamber of the high-pressure fuel pump during the fuel intake process. As a result, the fuel output from the low-pressure fuel circuit is not completely input into the high-pressure fuel pump, and the actual fuel supply from the low-pressure fuel circuit to the high-pressure fuel pump is reduced.

[0054] It should be noted that the correction factor for the theoretical fuel supply is used to correct the difference between the theoretical and actual fuel supply. This correction factor is related to the pump speed of the high-pressure fuel pump and the initial fuel pressure. With the initial fuel pressure remaining constant, a lower pump speed results in a lower amount of fuel being pumped by the high-pressure pump; conversely, a higher pump speed results in a higher amount of fuel being pumped. If the low-pressure fuel circuit input requires the high-pressure fuel pump to operate at a target speed, and the high-pressure pump speed is not the preset target speed, the fuel received by the high-pressure pump will not be the same as the input from the low-pressure fuel circuit. In this case, the theoretical fuel supply to the high-pressure fuel circuit needs to be corrected to obtain the actual fuel supply from the low-pressure circuit to the high-pressure circuit. Similarly, if the pump speed of the high-pressure fuel pump remains constant, the lower the first fuel pressure, the lower the amount of fuel in the oil pipe between the low-pressure and high-pressure oil circuits, and the lower the actual amount of fuel input from the low-pressure oil circuit to the high-pressure oil circuit; if the first fuel pressure is higher, the more fuel in the oil pipe between the low-pressure and high-pressure oil circuits, and the more actual amount of fuel input from the low-pressure oil circuit to the high-pressure oil circuit.

[0055] In practical implementation, the correction coefficient Map can be used to determine the correction coefficients corresponding to the current first fuel pressure and the high-pressure fuel pump speed. The compensation coefficient Map is: K_ = Z(X, Y), where K is the correction coefficient, X is the high-pressure fuel pump speed (rpm), Y is the first fuel pressure (bar), and the correction coefficient K is typically a value close to 1.0.

[0056] Step S204: Correct the theoretical fuel supply amount according to the correction coefficient to obtain the actual fuel supply amount.

[0057] In this embodiment, the theoretical oil supply from the low-pressure oil circuit to the high-pressure oil circuit can be corrected according to the correction coefficient, thereby obtaining the actual oil supply to the high-pressure oil circuit.

[0058] Understandably, the theoretical fuel supply from the low-pressure fuel circuit is typically set based on changes in vehicle operating conditions. If the actual fuel received by the high-pressure fuel pump is not the theoretical supply, the response to vehicle operating conditions may be inaccurate. Therefore, during actual fuel supply, the control signal of the fuel metering valve can be corrected using a correction factor, such as increasing the conduction time of the fuel metering valve, to effectively and accurately respond to changes in vehicle operating conditions. For example, when the first fuel pressure is at the fuel pressure threshold, K = 1.0, and no correction is needed for the fuel metering valve control signal. When the first fuel pressure is less than the fuel pressure threshold, K < 1.0 indicates a decrease in fuel supply capacity and low fuel pressure. Simultaneously, the duty cycle of the fuel metering valve control signal is corrected to increase the actual fuel supply to the high-pressure fuel pump.

[0059] Step S202 includes: Step S2021: Obtain the signal duty cycle of the control signal of the fuel metering valve.

[0060] It should be noted that the amount of fuel input to the high-pressure fuel pump is mainly affected by the pump speed and the opening duration of the fuel metering valve. With the fuel metering valve always open, a higher pump speed results in a larger amount of fuel being pumped in, while a lower pump speed results in a smaller amount of fuel being pumped in. Similarly, with a constant pump speed, a longer opening duration of the fuel metering valve means a longer time for the high-pressure fuel pump to receive fuel, resulting in a larger amount of fuel being pumped in; conversely, a shorter opening duration means a shorter time for the high-pressure fuel pump to receive fuel, resulting in a smaller amount of fuel being pumped in. In other words, the pump speed of the high-pressure fuel pump corresponds to the amount of fuel pumped per unit time, and the duty cycle of the control signal for the fuel metering valve, which is equivalent to the opening duration of the fuel metering valve, corresponds to the pumping time of the high-pressure fuel pump.

[0061] Therefore, before determining the theoretical fuel supply to the high-pressure fuel circuit, it is necessary to detect the pump speed of the high-pressure fuel pump and the duty cycle of the control signal for opening the fuel metering valve. In practice, the pump speed can be detected by a sensor or by detecting the engine speed, and the pump speed can be determined based on the ratio between the engine speed and the high-pressure fuel pump speed. Furthermore, the duty cycle of the control signal for the fuel metering valve is determined by the opening and closing duration of the fuel metering valve within one cycle.

[0062] Step S2022: Determine the theoretical oil supply quantity input to the high-pressure oil circuit based on the oil pump speed, the signal duty cycle, and the first mapping relationship.

[0063] It should be noted that the first mapping relationship is the correspondence between the oil pump speed, the duty cycle of the control signal, and the theoretical fuel supply. The first mapping relationship can be pre-stored in the electronic control unit in the form of a map. The map is as follows: The theoretical fuel supply Z input to the high-pressure oil pump is Z = f(X, Y); where X is the oil pump speed of the high-pressure oil pump, in rpm; and Y is the PWM duty cycle of the control signal of the fuel metering valve.

[0064] In practice, given the pump speed of the high-pressure oil pump and the duty cycle of the control signal, the theoretical oil supply to the high-pressure oil circuit can be determined by directly finding the first mapping relationship based on the pump speed of the high-pressure oil pump and the duty cycle of the control signal.

[0065] A third embodiment of the engine fuel supply system control method of this application is proposed based on the first or second embodiment described above. (See reference...) Figure 4 , Figure 4 This is a flowchart illustrating the third embodiment of the engine fuel supply system control method of the present invention.

[0066] In this embodiment, step S50 includes: Step S51: Obtain the target fuel pressure of the high-pressure fuel rail.

[0067] It should be noted that the target fuel pressure of the high-pressure fuel rail is the rail pressure corresponding to the amount of fuel that needs to be stored in the high-pressure fuel rail in response to changes in vehicle operating conditions. When the vehicle operating conditions change, the amount of fuel burned in the engine cylinders needs to change accordingly, which in turn changes the fuel injection quantity of the injectors, ultimately resulting in a change in the target fuel pressure in the high-pressure fuel rail.

[0068] Therefore, when the vehicle's operating status changes, it is necessary to determine the target fuel pressure of the high-pressure fuel rail. In practice, the target fuel pressure required to respond to the current change in the vehicle's operating status can be determined based on changes in the vehicle's operating status, or changes in engine torque, speed, etc.

[0069] Step S52: Adjust the signal duty cycle of the control signal for the fuel metering valve according to the target fuel pressure and the second fuel pressure.

[0070] It should be understood that the duty cycle of the control signal for the fuel metering valve is the duration of the valve's opening within one fuel injection cycle. With a fixed high-pressure fuel pump speed, a larger duty cycle in the control signal results in a longer effective pumping time for the high-pressure fuel pump, and consequently, a greater amount of fuel input to the high-pressure fuel circuit. Adjusting the amount of fuel input to the high-pressure fuel pump can be achieved by adjusting the duty cycle of the control signal.

[0071] In practice, once the second fuel pressure within the high-pressure fuel rail and the required target fuel pressure within the high-pressure fuel rail are determined, the second fuel pressure can be compared with the target fuel pressure. If the second fuel pressure equals the target fuel pressure, it indicates that the fuel quantity within the high-pressure fuel rail is sufficient to meet the vehicle's operating requirements, and in this case, the duty cycle of the fuel metering valve control signal does not need to be adjusted. However, if the second fuel pressure does not equal the target fuel pressure, the second fuel pressure needs to be adjusted, which can be done by adjusting the duty cycle of the fuel metering valve control signal.

[0072] Step S53: Adjust the actual oil supply to the high-pressure oil circuit according to the adjusted control signal.

[0073] Understandably, the adjusted duty cycle of the control signal can regulate the second fuel pressure to the target fuel pressure. Therefore, after adjusting the duty cycle of the control signal, the on-time of the fuel metering valve can be directly adjusted using the adjusted control signal, thereby regulating the actual fuel supply to the high-pressure fuel circuit, and thus regulating the second fuel pressure to the target fuel pressure to meet the fuel injection requirements in response to changes in vehicle operating conditions.

[0074] Step S51 includes: Step S511: Obtain engine speed and engine load.

[0075] It should be understood that controlling changes in vehicle operating status requires controlling changes in engine operating status, which necessitates determining the target fuel pressure within the high-pressure fuel rail. Engine speed and engine load are both parameters that influence engine performance. When engine speed changes, the corresponding movement frequency within the engine cylinders increases, resulting in an increase in the amount of fuel burned per unit time. When engine load changes, the energy required by the engine changes, meaning the amount of fuel that needs to be burned within the engine cylinders changes accordingly.

[0076] Engine speed refers to the engine speed at the moment the driver adjusts the vehicle's operating status; engine load refers to the energy the engine needs to provide at the moment the driver adjusts the vehicle's operating status. Engine load can be reflected through torque and intake air volume.

[0077] Determining the target fuel pressure on the high-pressure fuel rail requires first obtaining engine speed and engine load. In practice, at the moment of adjusting the vehicle's operating state, sensors can detect engine speed, as well as engine torque or intake air volume, thereby obtaining engine speed and engine load.

[0078] Step S512: Determine the target fuel pressure of the high-pressure fuel rail based on the engine speed, the engine load, and the second mapping relationship.

[0079] It should be noted that the second mapping relationship is the correspondence between engine speed, engine load, and the target fuel pressure of the high-pressure fuel rail. This second mapping relationship, based on extensive bench test data, has been calibrated and optimized, and is stored in the electronic control unit (ECU) in the form of a multi-dimensional map. In the multi-dimensional map, Z = f(X, Y), where engine speed and engine load are independent variables, and the target fuel pressure is the dependent variable.

[0080] X represents engine speed in rpm; Y represents engine load, which can be torque in Nm or intake air volume in g / s; Z represents target fuel pressure in bar.

[0081] In practice, given the engine speed and engine load, the target fuel pressure of the high-pressure fuel rail can be determined by looking up the multi-dimensional map corresponding to the second mapping relationship, based on the engine speed and engine load.

[0082] Of course, the electronic control unit can also collect multiple signals such as accelerator pedal opening, engine intake pressure and temperature, crankshaft and camshaft position, first fuel pressure and oxygen sensor, and analyze the torque demand of the vehicle's operating state based on these multiple signals, and calculate the engine's charging volume to determine the engine's target air-fuel ratio and the fuel injection quantity of the injector, and then calculate the target fuel pressure by combining the fuel pump speed of the high-pressure fuel pump.

[0083] Step S512 specifically includes: Step S5121: Obtain the current temperature of the high-pressure oil rail.

[0084] It should be noted that, considering the high-pressure fuel rail is a sealed space and the medium stored within it is fuel, the secondary fuel pressure within the high-pressure fuel rail will change under different temperatures. For example, at higher temperatures, the fuel within the high-pressure fuel rail expands, leading to an increase in the secondary fuel pressure. The current temperature of the high-pressure fuel rail refers to the temperature present at the high-pressure fuel rail when the secondary fuel pressure needs to be adjusted. The current temperature may be affected by factors such as coolant temperature, engine intake air temperature, and fuel temperature.

[0085] Therefore, when determining the target fuel pressure, it is also necessary to consider the impact of temperature on the fuel pressure within the high-pressure fuel rail in order to more accurately determine the target fuel pressure. In practice, a temperature sensor can be installed on one side of the high-pressure fuel rail to collect the current temperature of the high-pressure fuel rail in real time during vehicle operation.

[0086] Step S5122: Correct the second mapping relationship according to the current temperature to obtain the corrected second mapping relationship.

[0087] Understandably, given the current temperature of the high-pressure fuel rail, the current temperature can be incorporated into the second mapping relationship, thereby correcting the second mapping relationship. In this case, the second mapping relationship can be transformed into one where the independent variables are engine speed, engine load, and the current temperature of the high-pressure fuel rail, and the dependent variable is the target fuel pressure of the high-pressure fuel rail.

[0088] Of course, in this embodiment, multiple second mapping relationships can be established for different temperatures of the high-pressure fuel rail, and then the corresponding second mapping relationship can be selected according to the current temperature to obtain a second mapping relationship that can accurately determine the target fuel pressure.

[0089] Step S5123: Determine the target fuel pressure of the high-pressure fuel rail based on the engine speed, the engine load, and the corrected second mapping relationship.

[0090] Understandably, after correcting the second mapping relationship based on the current temperature of the high-pressure fuel rail, the target fuel pressure of the high-pressure fuel rail can be directly found from the corrected second mapping relationship using engine speed and engine load as a reference.

[0091] During the adjustment of the second fuel pressure, the engine fuel supply system can employ a dual-path control system (feedforward and feedback) to control the duty cycle of the fuel metering valve's control signal. The feedforward path determines the duty cycle of the fuel metering valve's control signal based on the target fuel pressure, the fuel quantity, and the high-pressure fuel pump's speed, using a high-pressure fuel pump characteristic map. This duty cycle is then used to quickly adjust the second fuel pressure to the target fuel pressure. The feedback path monitors the first fuel pressure between the high-pressure and low-pressure fuel lines in real time using a low-pressure sensor. A PID controller dynamically corrects the duty cycle of the fuel metering valve's control signal, compensating for deviations between the actual and theoretical fuel supply caused by fluctuations in the first fuel pressure. The duty cycles of the control signals calculated by the feedforward and feedback paths are then superimposed to generate a precise control signal for the fuel metering valve.

[0092] In addition, the engine fuel supply system dynamically calculates the second fuel pressure by comparing the actual fuel supply to the high-pressure fuel pump with the fuel injection quantity of the injector, and then compares the second fuel pressure with the target rail pressure to further adjust the fuel supply in a closed loop.

[0093] Furthermore, in this embodiment, an oxygen sensor can be used to continuously monitor the exhaust oxygen concentration, perform long-term closed-loop correction of the air-fuel ratio, and combine the corrected air-fuel ratio with the adjustment process of the second fuel pressure, thereby achieving a precise balance between the vehicle's power, economy, and emission requirements under all operating conditions.

[0094] In this embodiment, through multi-layer coordination of feedforward prediction, feedback correction, rail pressure closed loop and air-fuel ratio closed loop, high dynamic, high precision and high robustness control of fuel supply is achieved.

[0095] A fourth embodiment of the engine fuel supply system control method of this application is proposed based on any one of the first to third embodiments described above.

[0096] Reference Figure 5 , Figure 5 This is a schematic diagram of the first process of the fourth embodiment of the engine fuel supply system control method of the present invention.

[0097] In this embodiment, after step S10, the method further includes: Step S60: When the first fuel pressure is less than a preset pressure threshold, output a first fault signal. The first fault signal is used to indicate that the low-pressure oil circuit is in a fault state.

[0098] It should be understood that the engine fuel supply system includes low-pressure and high-pressure fuel lines. When an engine experiences a fuel supply abnormality, the existing system cannot directly identify the faulty line within either the low-pressure or high-pressure lines. Professional personnel are required to inspect each component in both lines individually, a complex and time-consuming process.

[0099] It should be noted that the preset pressure threshold is a pre-set pressure threshold used to determine whether there is a fuel supply fault in the low-pressure fuel circuit. This preset pressure threshold is less than the minimum first fuel pressure during normal fuel supply of the engine fuel supply system; that is, no matter how the control signal of the fuel metering valve is adjusted, the first fuel pressure cannot be adjusted to the preset pressure threshold. For example, during normal fuel supply of the engine fuel supply system, when the duty cycle of the fuel metering valve control signal is adjusted to the minimum, the first fuel pressure is 2 bar, then the preset pressure threshold can be 1.5 bar. The first fault signal is a characteristic signal that the low-pressure fuel circuit is in a faulty state. The first fault signal can be an image signal displayed on the central control panel, or a flashing warning light signal, etc.

[0100] In practice, the first fuel pressure collected by the low-pressure sensor can be compared with a preset pressure threshold. If the first fuel pressure is not less than the preset pressure threshold, it can be determined that the low-pressure fuel circuit has not malfunctioned; if the first fuel pressure is less than the preset pressure threshold, it can be directly determined that the low-pressure fuel circuit has malfunctioned.

[0101] Therefore, in this embodiment, the presence of a fault in the low-pressure oil circuit can be confirmed directly by a low-pressure sensor located between the low-pressure oil circuit and the high-pressure oil circuit, avoiding the need to check each component one by one when the engine fuel supply system malfunctions, thus effectively improving the efficiency of fault diagnosis.

[0102] In addition, refer to Figure 6 , Figure 6 This is a second flowchart illustrating the fourth embodiment of the engine fuel supply system control method of the present invention.

[0103] In this embodiment, after step S10, the following steps are also included: Step S70: When the first fuel pressure is not less than a preset pressure threshold, continuously acquire the second fuel pressure and record the adjustment time of the second fuel pressure.

[0104] It should be understood that in the event of a fault in the engine power supply system, the fault may be in the low-pressure fuel line, the high-pressure fuel line, or other components such as the fuel metering valve located between the high-pressure and low-pressure fuel lines.

[0105] It should be noted that the adjustment time for the second fuel pressure is the time required to adjust the second fuel pressure to the target fuel pressure when the second fuel pressure is not equal to the target fuel pressure. Considering that vehicle operation is usually dynamic, the adjustment of the second fuel pressure is a relatively frequent process during vehicle operation. For example, pressing the accelerator, pressing the brake, or turning on the air conditioner will all cause the second fuel pressure to be adjusted.

[0106] In this embodiment, if the first fuel pressure is not less than a preset pressure threshold, the possibility of a fault in the low-pressure fuel circuit can be ruled out, thus requiring a diagnosis of a fault in the high-pressure fuel circuit. During this process, the second fuel pressure and its adjustment duration need to be continuously monitored.

[0107] In practice, the first fuel pressure collected by the low-pressure sensor can be continuously used to determine the actual fuel supply to the high-pressure fuel circuit. Based on the actual fuel supply to the high-pressure fuel circuit, the fuel output from the high-pressure fuel rail within the high-pressure fuel circuit, and a preset rail pressure calculation model, the second fuel pressure of the high-pressure fuel rail is determined. When the process of adjusting the second fuel pressure begins, a timer is started to record the adjustment duration.

[0108] Step S80: If the second fuel pressure is not adjusted to the target fuel pressure when the adjustment time reaches the preset time, a second fault signal is output. The second fault signal is used to indicate that the high-pressure oil circuit is in a fault state.

[0109] It should be noted that the preset duration is a pre-set time length used to determine whether there is a fault in the high-pressure fuel circuit. This preset duration is longer than the maximum time required for the second fuel pressure to adjust to the target fuel pressure. For example, if the maximum time required for the second fuel pressure to adjust to the target fuel pressure is 5 seconds, then the preset duration can be set to 8 seconds. This maximum duration can be selected as the larger of the duty cycle increase duration and the duty cycle decrease duration. The duty cycle increase duration is the time required for the control signal duty cycle to adjust from the minimum duty cycle to the maximum duty cycle, and the duty cycle decrease duration is the time required for the control signal duty cycle to adjust from the maximum duty cycle to the minimum duty cycle.

[0110] In this embodiment, the second fault signal is a signal indicating that the high-pressure oil circuit is in a fault state. This second signal can be an image signal displayed on the central control panel, or a flashing warning light signal, etc. The representation method of the second signal is different from that of the first signal. For example, if the first signal controls the warning light to flash twice, the second signal can control the warning light to remain lit continuously.

[0111] In practice, the adjustment time of the second fuel pressure can be compared with the preset time. If the adjustment time reaches the preset time, it can be determined that the second fuel pressure cannot be adjusted to the target fuel pressure, and at this time, it can be determined that there is a fault in the high-pressure oil circuit.

[0112] Furthermore, in this embodiment, considering the case where the target fuel pressure is too low, even if there is a high-pressure pump blockage or injector leakage, the second fuel pressure can be adjusted to the target fuel pressure by adjusting the opening of the fuel metering valve.

[0113] To avoid the above problems, in this embodiment, if the first fuel pressure is not less than a preset pressure threshold, the target fuel pressure can be increased to a larger fuel pressure, thereby accurately detecting whether there is a fault in the high-pressure fuel circuit.

[0114] In practice, if the first fuel pressure is not less than a preset pressure threshold, the engine load can be increased and the opening of the fuel metering valve can be increased. Then, the adjustment time of the second fuel pressure can be detected. If the adjustment time reaches the preset time, it can be determined that there is a fault in the high-pressure oil circuit.

[0115] In this embodiment, by increasing the engine load and increasing the opening of the fuel metering valve, the target fuel pressure is increased, thus avoiding the problem of inaccurate detection of whether the high-pressure oil circuit is abnormal due to the target fuel pressure being too low.

[0116] Reference Figure 7 , Figure 7 This is a structural block diagram of the first embodiment of the engine fuel supply system control device of the present invention.

[0117] like Figure 7 As shown, the engine fuel supply system control device proposed in this embodiment of the invention includes: The pressure acquisition module 10 is used to acquire the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor; The fuel supply determination module 20 is used to determine the actual fuel supply to the high-pressure oil circuit based on the first fuel pressure. The oil output acquisition module 30 is used to acquire the oil output of the high-pressure oil rail in the high-pressure oil circuit; The pressure determination module 40 is used to input the actual fuel supply and the fuel output into the preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The fuel supply control module 50 is used to adjust the actual fuel supply to the high-pressure fuel circuit according to the second fuel pressure.

[0118] In this embodiment, the pressure acquisition module 10 can acquire the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor; the fuel supply determination module 20 can determine the actual fuel supply to the high-pressure oil circuit based on the first fuel pressure; the fuel output acquisition module 30 can acquire the fuel output of the high-pressure oil rail in the high-pressure oil circuit; the pressure determination module 40 can input the actual fuel supply and the fuel output into a preset rail pressure calculation model to determine the second fuel pressure of the high-pressure oil rail; and the fuel supply control module 50 can adjust the actual fuel supply to the high-pressure oil circuit based on the second fuel pressure. During the adjustment of the fuel supply, the actual fuel supply to the high-pressure oil circuit is determined by detecting the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit, and then the second fuel pressure of the high-pressure oil rail is determined based on the actual fuel supply and the fuel output of the high-pressure oil rail. This allows for the acquisition of the second fuel pressure within the high-pressure oil rail without the need for a rail pressure sensor, effectively reducing the cost of fuel supply adjustment.

[0119] The specific implementation of the engine fuel supply system control device of the present invention can be referred to the above-described method embodiments, and will not be repeated here.

[0120] Reference Figure 8 , Figure 8 This is a first structural schematic diagram of the engine fuel supply system of the present invention. Based on... Figure 8 The first embodiment of the engine fuel supply system of this application is presented.

[0121] In this embodiment, the engine fuel supply system includes: Low-pressure oil circuit 1, the low-pressure oil circuit 1 includes: a low-pressure oil pump 11 and a fuel filter 12 connected by an oil pipe; The high-pressure oil circuit 2 includes a high-pressure oil pump 21, a high-pressure oil rail 22, and an injector 23 connected by an oil pipe; the high-pressure oil pump 21 is also equipped with a high-pressure oil outlet valve 211, which is used to control the fuel input from the high-pressure oil pump to the high-pressure oil rail 22.

[0122] Fuel metering valve 3 is installed on the oil pipe between fuel filter 12 and high-pressure oil pump 21; Low-pressure sensor 4 is installed on the oil pipe between the fuel filter 12 and the fuel metering valve 3; The electronic control unit 5 is connected to the low-pressure sensor 4 and the fuel metering valve 3 in the high-pressure oil circuit 1. The electronic control unit is used to execute the engine fuel supply system control method in any of the above-described engine fuel supply system control method embodiments.

[0123] In this embodiment, by setting a low-pressure sensor, during the process of adjusting the fuel supply, the actual fuel supply to the high-pressure fuel line is determined by detecting the first fuel pressure between the low-pressure fuel line and the high-pressure fuel line. Then, based on the actual fuel supply and the fuel output of the high-pressure fuel rail, the second fuel pressure of the high-pressure fuel rail is determined. Without the need to set a rail pressure sensor, the second fuel pressure in the high-pressure fuel rail can be obtained, which effectively reduces the cost of fuel supply adjustment.

[0124] Reference Figure 9 , Figure 9This is a second structural schematic diagram of the engine fuel supply system of the present invention. In this embodiment, the fuel metering valve 3 can be disposed inside the high-pressure fuel pump 21, located behind the fuel inlet connected to the low-pressure fuel line 1. The low-pressure sensor 4 can be disposed on the pipeline at the fuel inlet, which can be made of metal, and the low-pressure sensor 4 can be mounted on the fuel inlet. By disposing of both the fuel metering valve 3 and the low-pressure sensor 4 at the fuel inlet, the wiring harnesses of the fuel metering valve 3 and the low-pressure sensor 4 can share a single wiring harness connector. This connector can be disposed on the side of the high-pressure fuel pump 21 away from the low-pressure fuel line 1, and close to the high-pressure fuel pump 21.

[0125] In addition, refer to Figure 10 , Figure 10 This is a schematic diagram of the fuel metering valve adjustment structure in the engine fuel supply system of the present invention. In this embodiment, the engine fuel supply system may further include: accelerator pedal sensor 6, temperature sensor 7, camshaft position sensor 8, crankshaft speed sensor 9, etc. During the adjustment of the fuel supply, the above-mentioned devices can collect the engine operating status, and then the electronic control unit 5 can determine the target fuel pressure. Based on the second fuel pressure and the target fuel pressure, the signal duty cycle of the control signal of the fuel metering valve is adjusted to adjust the second fuel pressure to the target pressure.

[0126] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0127] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0128] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0129] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for controlling an engine fuel supply system, characterized in that, The engine fuel supply system includes: a low-pressure fuel line, a high-pressure fuel line, and a low-pressure sensor disposed between the high-pressure fuel line and the low-pressure fuel line; The method includes: The first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit is obtained through the low-pressure sensor; The actual fuel supply to the high-pressure fuel circuit is determined based on the first fuel pressure. Obtain the oil output of the high-pressure oil rail in the high-pressure oil circuit; The actual fuel supply and the fuel output are input into a preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The actual fuel supply to the high-pressure fuel circuit is adjusted according to the second fuel pressure.

2. The engine fuel supply system control method as described in claim 1, characterized in that, The step of determining the actual fuel supply to the high-pressure fuel circuit based on the first fuel pressure includes: Obtain the pump speed of the high-pressure oil pump in the high-pressure oil circuit; Obtain the theoretical oil supply quantity input to the high-pressure oil circuit; The correction factor for the theoretical fuel supply is determined by the first fuel pressure and the fuel pump speed. The actual fuel supply is obtained by correcting the theoretical fuel supply based on the correction factor.

3. The engine fuel supply system control method as described in claim 2, characterized in that, The theoretical oil supply quantity input to the high-pressure oil circuit includes: The signal duty cycle for acquiring the control signal from the fuel metering valve; The theoretical oil supply to the high-pressure oil circuit is determined based on the oil pump speed, the signal duty cycle, and the first mapping relationship, whereby the first mapping relationship is the correspondence between the oil pump speed, the signal duty cycle of the control signal, and the theoretical oil supply.

4. The engine fuel supply system control method as described in claim 1, characterized in that, The step of adjusting the actual fuel supply to the high-pressure fuel circuit according to the second fuel pressure includes: Obtain the target fuel pressure of the high-pressure fuel rail; The signal duty cycle of the control signal for adjusting the fuel metering valve is adjusted according to the target fuel pressure and the second fuel pressure. The actual oil supply to the high-pressure oil circuit is adjusted according to the adjusted control signal.

5. The engine fuel supply system control method as described in claim 4, characterized in that, The process of obtaining the target fuel pressure of the high-pressure fuel rail includes: Obtain engine speed and engine load; The target fuel pressure of the high-pressure fuel rail is determined based on the engine speed, the engine load, and a second mapping relationship, whereby the second mapping relationship is the correspondence between engine speed, engine load, and the target fuel pressure of the high-pressure fuel rail.

6. The engine fuel supply system control method as described in claim 5, characterized in that, The step of determining the target fuel pressure of the high-pressure fuel rail based on the engine speed, the engine load, and the second mapping relationship further includes: Obtain the current temperature of the high-pressure oil rail; The corrected second mapping relationship is obtained by correcting the second mapping relationship based on the current temperature; The target fuel pressure of the high-pressure fuel rail is determined based on the engine speed, the engine load, and the corrected second mapping relationship.

7. The engine fuel supply system control method according to any one of claims 1 to 6, characterized in that, After obtaining the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor, the method further includes: When the first fuel pressure is less than a preset pressure threshold, a first fault signal is output, which is used to indicate that the low-pressure oil circuit is in a fault state.

8. The engine fuel supply system control method as described in claim 7, characterized in that, The step of obtaining the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor also includes: While the first fuel pressure is not less than a preset pressure threshold, the second fuel pressure is continuously acquired and the adjustment time of the second fuel pressure is recorded. If the second fuel pressure is not adjusted to the target fuel pressure when the adjustment time reaches the preset time, a second fault signal is output. The second fault signal is used to indicate that the high-pressure oil circuit is in a fault state.

9. A control device for an engine fuel supply system, characterized in that, The engine fuel supply system includes: a low-pressure fuel line, a high-pressure fuel line, and a low-pressure sensor disposed between the high-pressure fuel line and the low-pressure fuel line; The device includes: The pressure acquisition module is used to acquire the first fuel pressure between the low-pressure oil circuit and the high-pressure oil circuit through the low-pressure sensor; The fuel supply quantity determination module is used to determine the actual fuel supply quantity input to the high-pressure fuel circuit based on the first fuel pressure. The oil output acquisition module is used to acquire the oil output of the high-pressure oil rail in the high-pressure oil circuit; The pressure determination module is used to input the actual fuel supply and the fuel output into a preset rail pressure calculation model to determine the second fuel pressure of the high-pressure fuel rail; the preset rail pressure calculation model is constructed based on the mass balance principle within the high-pressure fuel rail. The fuel supply control module is used to adjust the actual fuel supply to the high-pressure fuel circuit according to the second fuel pressure.

10. An engine fuel supply system, characterized in that, include: The low-pressure oil circuit includes a low-pressure oil pump and a fuel filter connected by an oil pipe. The high-pressure oil circuit includes a high-pressure oil pump, a high-pressure oil rail, and an injector connected by oil pipes. A fuel metering valve is installed on the oil pipe between the fuel filter and the high-pressure fuel pump; A low-pressure sensor is installed on the oil pipe between the fuel filter and the fuel metering valve; An electronic control unit is connected to the low-pressure sensor and the fuel metering valve in the high-pressure oil circuit. The electronic control unit is used to execute the engine fuel supply system control method according to any one of claims 1 to 8.

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