Method for dynamically controlling injected fuel pressure applicable to fuel injection systems with an air-fuel mixture formed before entering the combustion chamber, system and engine

Abstract

The present invention relates to a method for dynamically controlling the pressure of injected fuel, which is applicable to fuel injection systems with an air-fuel mixture and is capable of controlling the pressure of a fuel pump by PWM in PFI engines, specifically in order to increase the pressure; a system that implements said method; and an engine provided with said system, wherein said system is provided with at least one fuel pump, preferably, but not necessarily, two or more pumps, and an engine equipped with said system. This approach provides a series of benefits, such as increased reliability of the pressurisation system with redundancy, greater flow flexibility in PFI injectors, significantly reduced fuel consumption due to decreased electrical load, minimised fuel recirculation, reduced load on the engine of the vehicle, and the ability to monitor system leaks and the health status of the fuel pumps.

Description

Descriptive Report of the Invention Patent for "DYNAMIC CONTROL METHOD FOR INJECTED FUEL PRESSURE APPLICABLE TO FUEL INJECTION SYSTEMS WITH AIR-FUEL MIXTURE FORMED BEFORE ENTERING THE COMBUSTION CHAMBER, SYSTEM AND ENGINE"

[0001] The present invention relates to the field of fuel injection control system engineering in engines in general, with a greater focus on those powered by diesel and renewable fuels, more precisely to a method and system for dynamic control of injected fuel pressure, as well as to an engine equipped with this system. STATE OF THE ART

[0002] Internal combustion engines (ICEs) that utilize indirect fuel injection systems, known as PFI (Port Fuel Injection), are widely used in the automotive industry due to their simplicity, reliability, and lower cost. In the PFI system, fuel is injected into the intake manifold before the intake valve, allowing it to mix with air before entering the combustion chamber. This is crucial to ensure efficient and complete combustion.

[0003] To ensure fuel is injected at the ideal moment, there's the concept of the "injection window." This window is carefully synchronized so that fuel is injected into the intake manifold at the exact moment the intake valve opens, allowing for a homogeneous mixture with the air.

[0004] However, a significant problem with engines that use PFI is the accumulation of fuel on the intake valves when injection occurs outside this ideal window or in excess. This buildup can result in carbon deposits on the valves, negatively impacting airflow and engine efficiency.

[0005] Over time, these deposits increase fuel consumption and raise pollutant emissions, something especially problematic in a scenario of increasingly stringent environmental regulations. To mitigate these problems, it is crucial that the injection system operates with high precision.

[0006] In the PFI system, the injectors are designed with a fixed flow rate, determined by the diameter of the outlet orifice. These are sized to meet fuel demand under full load conditions, ensuring that the engine does not suffer from fuel starvation in extreme situations, such as maximum acceleration.

[0007] However, when the engine operates under low load conditions, such as idling or at a constant speed, the injectors, which were designed for high demand, end up releasing more fuel than necessary. This leads to fuel waste and atomization problems.

[0008] Atomization is the process by which fuel is sprayed into small droplets to mix uniformly with air. When there is excess fuel, this atomization is compromised, impairing combustion efficiency and resulting in higher emissions.

[0009] The fuel supply system in PFI engines consists of a fuel pump, a pressure regulating valve, and injectors. The pump supplies fuel at a constant pressure, while the regulating valve ensures that this pressure remains stable, regardless of demand.

[0010] However, the pump is designed to operate at its maximum capacity under all conditions, resulting in excess fuel in low-load situations. This excess is recirculated back to the tank through the regulating valve, creating a continuous recirculation cycle.

[0011] This continuous recirculation cycle generates significant fuel waste and increases electricity consumption. The pump consumes a considerable amount of energy to maintain the high flow rate, even when the engine doesn't need it.

[0012] Furthermore, this additional consumption overloads the vehicle's electrical system, forcing the alternator to work harder, which in turn increases fuel consumption. This reduces overall efficiency, especially in modern vehicles where energy saving is a priority.

[0013] Another problem is the accelerated wear of components, such as the fuel pump and the regulating valve, which operate continuously at high capacity. This wear can result in high maintenance costs and premature failures.

[0014] The heat generated by continuous recirculation is also a concern. The fuel returning to the tank can heat up due to friction and the constant work of the pump, increasing the risk of "vapor lock," which can result in ignition failures, especially in hot climates.

[0015] In contrast, direct injection (DI) engines inject fuel directly into the combustion chamber, allowing for more precise control of the amount and timing of the injection.

[0016] However, DL engines face challenges such as the formation of carbon deposits in the combustion chambers and fine particulate emissions due to high injection pressure, which has become a growing concern in terms of emissions.

[0017] Compared to the DL system, the PFI is less prone to the formation of fine particles, but its efficiency is limited by the fixed pressure and flow rate of the injectors.

[0018] To mitigate these limitations, a promising approach is the implementation of variable pressure injection systems, allowing dynamic pressure adjustments according to engine demand.

[0019] A variable pressure system would adjust the pump pressure based on engine load, reducing electrical power consumption and eliminating the need for constant fuel recirculation.

[0020] With a variable pressure system, fuel atomization would be improved, resulting in more efficient combustion and a significant reduction in emissions.

[0021] Furthermore, Dl engines would also benefit from this technology, minimizing deposit formation and reducing particulate emissions.

[0022] Hybrid vehicles could maximize the efficiency of the combustion engine by integrating variable pressure injection systems, extending the lifespan of the batteries.

[0023] However, implementing variable pressure systems presents challenges, such as the need for new sensors and more sophisticated software, increasing the initial cost, but offsetting it in the long run.

[0024] Furthermore, in the fleet sector, such as trucks and agricultural vehicles, efficiency and operational cost reduction can be significantly improved with variable pressure.

[0025] In turbocharged engines, variable pressure optimizes the air-fuel ratio, preventing detonation under high pressure.

[0026] Therefore, the transition to injection systems with variable pressure control represents a strategic solution to improve efficiency and reduce emissions in internal combustion engines, extending their relevance in a market focused on sustainability.

[0027] In addition to the applications already mentioned, variable pressure can be especially advantageous for engines in commercial vehicles that operate under constant and high loads, such as city buses or trucks that travel long distances on highways. The ability to adjust injection pressure ensures that the engine is always using the ideal amount of fuel, reducing consumption and extending the lifespan of components.

[0028] In the context of agricultural vehicles, such as tractors and harvesters, which operate under varying load conditions and often on difficult terrain, the ability to adjust injection pressure allows for optimizing engine efficiency according to the specific demands of each task. This not only improves efficiency but also reduces engine wear, lowering maintenance costs.

[0029] In industrial sectors where off-road vehicles are used for construction, mining, and other heavy-duty operations, variable pressure ensures that engines are more responsive and efficient in challenging environments. This is particularly useful when operating conditions change rapidly, requiring immediate adjustments to maintain engine efficiency.

[0030] Variable pressure technology can also be integrated into advanced hybrid systems. In hybrid vehicles that alternate between using the combustion engine and the electric motor, adjustable injection pressure allows for optimizing the efficiency of the combustion engine. during periods when it is activated to recharge the battery or provide additional power.

[0031] An interesting application of this technology is in the emergency vehicle sector, such as ambulances and rescue vehicles, where engine efficiency and reliability are crucial. Adjusting injection pressure in real time can ensure that these vehicles operate at peak efficiency, even under high-demand and urgent conditions.

[0032] In regions with extremely cold climates, the ability to vary injection pressure can significantly aid in cold engine starts. By temporarily increasing fuel pressure, it's possible to improve fuel atomization, facilitating ignition and reducing the need for rich mixtures, which increase emissions during initial warm-up.

[0033] In high-altitude regions, where air density is lower, a variable pressure system can adjust the amount of fuel injected to ensure that the air-fuel ratio remains ideal, even when the rarefied air could compromise combustion.

[0034] In terms of sustainability, the transition to variable pressure injection systems aligns with global efforts to reduce greenhouse gas emissions. More efficient engines mean lower fossil fuel consumption and therefore a direct reduction in CO2 emissions.

[0035] The use of alternative fuels, such as biofuels and compressed natural gas (CNG), can also be optimized with variable pressure injection systems. These fuels have different physical properties compared to traditional gasoline, and the ability to adjust injection pressure ensures that combustion efficiency is maximized.

[0036] The use of synthetic fuels, produced from captured CO2 and green hydrogen, could become more viable with the adaptation of ICE engines to operate efficiently with these new fuels, utilizing the flexibility of variable pressure to optimize combustion.

[0037] Variable pressure is particularly beneficial for flex-fuel engines that use gasoline and ethanol blends. In flex-fuel engines, where the proportion of ethanol in the mixture can vary, adjusting the injection pressure ensures that the engine runs optimally with any fuel mixture.

[0038] As the automotive industry moves towards electrification, variable pressure technology can serve as a bridge to ensure that internal combustion engines remain competitive and efficient during the transition to cleaner technologies.

[0039] The digitalization of modern vehicles, which includes connectivity and telemetry, allows injection systems to be adjusted remotely through over-the-air software updates, ensuring that vehicles remain efficient throughout their lifespan.

[0040] Connectivity also enables the collection of real-time operating data, allowing control systems to predict and adjust injection pressure requirements to maximize efficiency, especially in commercial fleets where predictive maintenance is essential to reduce costs.

[0041] Autonomous vehicles can greatly benefit from variable pressure technology, since continuous engine optimization is crucial to maximizing efficiency and ensuring reliability during long periods of operation without human intervention.

[0042] Another promising application is in the use of hydrogen engines, which require extremely precise control to avoid detonation and ensure efficient combustion. The ability to vary injection pressure can be a decisive factor for the success of hydrogen-powered engines.

[0043] By extending the service life of internal combustion engines, variable pressure contributes to the principles of circular economy, reducing the need to produce new engines and components, thus decreasing the environmental impact of automotive production.

[0044] Finally, the adoption of this technology can improve the residual value of vehicles in the used car market, since engines equipped with more efficient injection systems are more attractive to buyers seeking to reduce fuel consumption and emissions.

[0045] In short, the evolution towards injection systems with variable pressure control is not only a technical solution to improve efficiency and reduce emissions, but also a vital strategy to prolong the relevance of internal combustion engines in a future increasingly focused on sustainability and the transition to clean technologies.

[0046] Engines designed for high-performance applications, extreme conditions, or specialized systems requiring more complex fuel delivery utilize multiple fuel pumps.

[0047] In high-performance engines, such as those used in racing vehicles, multiple pumps are essential to meet the high demand for fuel pressure and flow, especially at high power and acceleration levels. Large diesel engines, such as those used in trucks, locomotives, and marine vessels, also make use of multiple pumps, often to to achieve the extremely high pressures required in direct injection systems, such as Common Rail Diesel.

[0048] Furthermore, flex-fuel (or dual-fuel) and multi-fuel engines, which operate on different types of fuel, can utilize multiple pumps to adapt fuel delivery according to the density and energy demand of the selected fuel. In aeronautical applications, aircraft engines frequently employ multiple pumps to ensure redundancy and reliable operation at extreme altitudes and conditions, where failures can have serious consequences. Similarly, hybrid engines and electric systems with range extenders can integrate multiple pumps to optimize fuel consumption and meet the varying demands of the hybrid system.

[0049] In industrial applications, such as power generators and heavy machinery, multiple pumps are used to modulate the delivery of large volumes of fuel and improve efficiency in high-capacity systems. Advanced engines, such as those employing HCCI (Homogeneous Charge Compression Ignition) or gas-directed injection (GDI) with alternative fuels, may also require multiple pumps to withstand extreme pressures and provide precise control of fuel delivery. In all these cases, multiple pumps are used to ensure redundancy, divide the workload, dynamically adjust fuel flow and pressure, and meet the specific needs of each application.

[0050] In this regard, patent document BR1 12015002907A2 describes a system and method for reducing the amount of original fuel consumed in multifuel engines, allowing the efficient use of alternative fuels such as LPG. methane or other substances. The solution uses a pressure emulator that alters the signal sent by the pressure sensor to the Electronic Control Unit (ECU), dynamically adjusting the high-pressure pump pressure. This adjustment reduces system pressure without triggering fault diagnostics in the ECU, ensuring continuous engine operation. The document also addresses the prevention of technical problems, such as injector blockages or overheating, by maintaining a minimum amount of original fuel under certain conditions.

[0051] Although the document offers a solution for pressure control in multifuel engines, it consistently focuses on pressure reduction without addressing pressure increase or the control of multiple pumps, which are essential elements for implementing more advanced systems. These challenges include managing cavitation and operational stability under high demands, as well as integrating dynamic variables such as engine load and airflow.

[0052] Furthermore, document BR112015002907A2 uses a pressure emulator that manipulates signals from a single pump. This contrasts with the need for a coordinated approach for multiple pumps, necessary to achieve greater efficiency and control in motors operating under varied and demanding conditions.

[0053] In summary, while patent document BR1 12015002907A2 contributes to pressure control in multifuel systems, it does not provide a sufficient basis for implementing advanced solutions that integrate multiple pumps, dynamic pressure control, and synchronization with engine conditions. Therefore, the proposal described in this text presents a significant technical evolution, addressing crucial gaps to maximize the efficiency and sustainability of internal combustion engines.

[0054] Therefore, the present invention seeks to overcome the lack of a solution capable of controlling the pressure of multiple fuel pumps via PWM (Pulse Width Modulation - a control technique that adjusts the width of pulses in a periodic signal to regulate the power delivered to a device) in PFI (indirect injection) engines, specifically to increase the pressure, rather than reduce it, in a manner synchronized with the engine load. OBJECTIVES OF THE INVENTION

[0055] The present invention aims to provide a method for dynamically controlling injected fuel pressure applicable to air-fuel mixture fuel injection systems capable of controlling fuel pump pressure via PWM in PFI engines, specifically to increase pressure. The invention relates to a system that implements said method and an engine equipped with said system, said system having at least one fuel pump, preferably, but not necessarily, two or more pumps. This approach provides a number of benefits, such as increased reliability of the pressurization system with redundancy, greater flow flexibility in PFI injectors, significant reduction in fuel consumption by decreasing the electrical load, minimization of fuel recirculation, reduction of load on the vehicle engine, and the ability to monitor leaks in the system and the health status of the fuel pumps. BRIEF DESCRIPTION OF THE INVENTION

[0056] Aiming to overcome the drawbacks of the prior art, the present invention describes a method for dynamically controlling injected fuel pressure applicable to fuel injection systems with an air-fuel mixture formed before entering the system. combustion chamber, the said method comprising the steps of • Determine an initial operating condition for the engine; • Adjust the fuel pressure injected during initial engine operation by controlling the power supplied to at least one fuel pump through pulse width modulation; • Monitor the injected fuel pressure in real time using at least one pressure sensor; • Monitor an engine operating condition in real time and compare said real-time engine operating condition with a reference engine condition; • Adjust the fuel pressure to a pressure different from the fuel pressure injected at startup as soon as the engine's reference condition is reached; • Monitor the engine's operating condition in real time; • Adjust the injected fuel pressure according to the engine's operating condition through a closed loop; • Adjust the opening time of at least one injector so that it operates in synchronous cooperation with the previously adjusted injected fuel pressure; • Monitor the pressure of the injected fuel in real time using at least one pressure sensor.

[0057] Additionally, with the aim of overcoming the drawbacks of the prior art, the present invention describes a dynamic fuel injection pressure control system that performs the above method, said system comprising... • at least one fuel pump; • at least one pressure sensor; • at least one means of verifying the initial condition; • at least one control unit; • at least one fuel injector.

[0058] Also with the aim of overcoming the drawbacks of the prior art, the present invention describes an engine equipped with the above-defined dynamic fuel injection pressure control system that performs the above-defined method. BRIEF DESCRIPTION OF THE FIGURES Figure 1 - Schematic view of the system that is the subject of the present invention. Figure 2 - Overview of the method that is the subject of the present invention. DETAILED DESCRIPTION OF THE FIGURES

[0059] The solution described is a significant innovation in fuel pressure control for internal combustion engines. By integrating software and hardware, it is able to manage at least one fuel pump without the need for pressure regulating valves. This represents an advance in the efficiency of the fuel injection system, allowing the engine's energy demand to be received and processed accurately and efficiently. Communication with the ECU or data collection on a standardized communication bus ensures that the system can adjust fuel pressure according to engine needs, resulting in more precise and adaptable control.

[0060] Furthermore, controlling the fuel pumps via PWM, where the duty cycle directly influences system pressure, offers a dynamic and flexible approach to fuel pressure control. The ability to configure the setpoint of Pressure in the system software or as a function of the engine ECU provides further customization according to the specifics of each engine and operating conditions.

[0061] Duty cycle and pressure setpoint are fundamental concepts for the operation of fuel pumps in modern systems, especially those with electronic injection. The duty cycle refers to the percentage of time the pump is active during an operating cycle, being a ratio between the time the pump is energized and the total cycle time. In modern engines, the duty cycle is adjusted by the ECU (Electronic Control Unit) to regulate fuel flow, save energy, and maintain stable fuel pressure. For example, during idle, the pump may operate with a 40% duty cycle, while at maximum acceleration it may increase to 80% or more, ensuring adequate fuel supply.

[0062] The pressure setpoint is the target pressure that the pump must maintain in the system, defined by the ECU according to engine conditions such as load, RPM, and injection type (PFI or DL). Fuel pressure needs to be consistent to ensure efficient atomization in the injectors. To achieve this, the system uses sensors that monitor pressure in real time. If the measured pressure is lower than the setpoint, the ECU increases the pump's duty cycle to compensate; if it is higher, the duty cycle is reduced or a relief valve is activated. In PFI injection systems, the typical pressure ranges between 3 and 5 bar, while in DL systems it can reach up to 250 bar due to the higher atomization and efficiency requirements.

[0063] Thus, the duty cycle adjusts the pump's operation to reach the pressure setpoint determined by the ECU, optimizing fuel delivery for different operating conditions. motor. This interaction ensures energy efficiency, extends the pump's lifespan, and maintains optimal injection system performance.

[0064] Another important aspect is the continuous monitoring of internal faults and leaks, carried out by tracking the electrical current, voltage, and fuel pressure drops in the system. This contributes to the safety and reliability of the fuel injection system, allowing for the early detection of problems and the implementation of corrective measures.

[0065] Thus, the present invention describes a method for dynamically controlling injected fuel pressure applicable to fuel injection systems with an air-fuel mixture formed before entering the combustion chamber, said method comprising the steps of • determine an initial operating condition for motor 1; • adjust the fuel pressure injected in the initial operating condition of engine 2 by controlling the power supplied to at least one fuel pump 104 by pulse width modulation; • monitor the injected fuel pressure in real time 3 by means of at least one pressure sensor 103; • monitor a real-time engine operating condition and compare said real-time engine operating condition with a reference engine condition 4; • Adjust the fuel pressure to a pressure different from the fuel pressure injected at startup 5 as soon as the engine's reference condition is reached; monitor the engine's operating condition in real time 6; • Adjust the injected fuel pressure according to the engine's operating condition 7 by means of a closed loop; • adjust the opening time 8 of at least one fuel injector 101 so as to operate in synchronous cooperation with the previously adjusted injected fuel pressure; • monitor the injected fuel pressure in real time 9 by means of at least one pressure sensor 103.

[0066] Adjusting the injector opening time is fundamental to ensuring the ideal air-fuel mixture in the engine, directly influencing performance, energy efficiency, and pollutant emissions. A well-calibrated opening time ensures that the exact amount of fuel is injected into the combustion chamber, avoiding both rich (excess fuel) and lean (lack of fuel) mixtures by improving fuel atomization. This is especially critical under variable operating conditions, such as sudden accelerations or load changes, where injection precision is essential to avoid ignition failures, premature component wear, and increased fuel consumption. Furthermore, proper adjustment improves combustion, reducing carbon and nitrogen oxide (NOx) emissions, and meeting increasingly stringent environmental regulations.

[0067] The initial operating condition of the motor is understood to be the ambient temperature before starting or the motor load at a given initial instant. Similarly, the real-time operating condition of the motor is understood to be the operating temperature or the motor load at a later instant than the initial instant. Likewise, the reference condition of the motor is understood to be the operating condition... ideal, meaning the ideal operating temperature or the ideal load condition of the motor.

[0068] In one particular embodiment, the present invention describes a method where steps 1, 2, 3, 4, 5, 6, 7, 8, and 9 are performed sequentially.

[0069] In another particular embodiment, the present invention describes a method where steps 3, 4, 6, and 9 are performed continuously.

[0070] In one particular embodiment, the present invention describes a method where steps 3, 4, 6, and 9 are performed intermittently.

[0071] In yet another particular embodiment, the present invention describes a method wherein the initial operating condition of the motor comprises an operating condition of the motor at an instant prior to the actual operating condition of the motor.

[0072] In an alternative embodiment, the present invention describes a method where the initial operating condition of the motor comprises the ambient temperature before starting.

[0073] In another alternative embodiment, the present invention describes a method where the ambient temperature before departure is determined by means of at least one temperature sensor.

[0074] In yet another alternative embodiment, the present invention describes a method where the ambient temperature before departure is determined by means of modeling performed by at least one control unit 105.

[0075] In an alternative embodiment, the present invention describes a method in which the power supplied to the pump of Fuel 104 is controlled by means of pulse width modulation according to the engine's operating condition.

[0076] In another alternative embodiment, the present invention describes a method wherein the equivalent voltage supplied to the fuel pump (104) is less than or equal to the electrical voltage available in an electrical system to which said pump is associated and is controlled by means of pulse width modulation according to an operating limit of said fuel pump (104).

[0077] In this case, the voltage of the electrical system to which the pump is connected refers to the electrical voltage available in the vehicle, supplied by the battery and alternator. In conventional vehicles, this voltage is usually 12 volts for low-voltage systems, but in hybrid and electric vehicles it can be higher, such as 48 volts or even hundreds of volts for high-voltage systems.

[0078] The maximum equivalent voltage supplied to the fuel pump is controlled by pulse width modulation (PWM), a method directly related to the duty cycle. As mentioned earlier, the duty cycle, defined as the percentage of time an electrical signal is "on" during a complete cycle, determines the average voltage supplied to the pump.

[0079] When the fuel pump is powered by a PWM system, the supplied voltage is not continuous, but pulsed. The ECU adjusts the duty cycle to control the average power delivered to the pump. For example, a 50% duty cycle means that the electrical signal is "on" half the time, resulting in an average voltage equivalent to half the pump's nominal voltage. If the duty cycle is increased to 80%, the average voltage increases proportionally, approaching the nominal value without exceeding it, as specified in the sentence.

[0080] This relationship is crucial for protecting the pump and ensuring its operation within operational limits. Duty cycle adjustment also allows the pump to meet the engine's varying fuel demands by regulating flow and pressure without exceeding nominal voltage limits, thus optimizing efficiency and durability.

[0081] In yet another alternative embodiment, the present invention describes a method whereby the fuel pressure is adjusted to a higher pressure than the fuel injected at startup, according to the real-time engine operating condition.

[0082] In yet another alternative embodiment, the present invention describes a method in which the opening time of fuel injector 101 is adjusted according to the previously adjusted injected fuel pressure and the engine operating condition.

[0083] In another alternative embodiment, the present invention describes a method, wherein said method operates on at least two fuel pumps 104.

[0084] Additionally, the present invention describes a dynamic fuel injection pressure control system that performs the method defined above, said system comprising • at least one fuel pump 104; • at least one 103 pressure sensor; • at least one means of verifying the initial condition; • at least one 105 control unit; • at least one fuel injector 101 .

[0085] In a particular embodiment, the present invention describes a system, wherein said system comprises at least two fuel pumps 104.

[0086] In another particular embodiment, the present invention describes a system where the control unit 105 is capable of executing the aforementioned method.

[0087] A control unit (CDU) is understood to be an electronic control unit that manages and monitors specific functions in vehicles, such as fuel injection, ignition, emissions, and engine performance. It uses sensors to collect real-time data and processes this information to adjust vehicle systems efficiently and precisely, ensuring optimized and safe operation. An ECU (Electronic Control Unit) is understood to be the central engine control system that manages and coordinates various electronic components and sensors to ensure optimized engine operation. The ECU receives information from various sensors, such as the intake manifold absolute pressure sensor and the knock sensor, processes this data, and makes precise adjustments to fuel injection, ignition, and other engine parameters.Its goal is to maximize engine performance, efficiency, and durability, while simultaneously reducing pollutant emissions and adapting to different operating conditions.

[0088] In a particular embodiment, the present invention describes a system where the fuel pump 104 is controlled by pulse width modulation (PWM).

[0089] In another particular embodiment, the present invention describes a system where the adjustment of the injected fuel pressure is carried out by means of a closed loop.

[0090] In another particular embodiment, the present invention describes a system where the adjustment of the injector opening time of Fuel injection (fuel injection) is carried out in synchronous cooperation with the previously adjusted injected fuel pressure.

[0091] In a particular embodiment, the present invention describes a system wherein the means for measuring the initial condition (not shown in Figure 1) comprises at least one motor load sensor.

[0092] The term "engine condition monitoring" refers to methods used to measure the load of internal combustion engines (ICEs), such as the MAP (Manifold Absolute Pressure) sensor, which measures the pressure in the intake manifold to assess vacuum or pressure relative to engine load; the MAF (Mass Air Flow) sensor, which directly measures the mass of air admitted, indicating airflow as a function of load; and the TPS (Throttle Position Sensor), which monitors the throttle position, reflecting the load demand by the driver. Additionally, the Lambda (or oxygen) sensor measures the air-fuel ratio in the mixture, helping to identify high loads, which generally require richer mixtures to optimize engine performance. These sensors work independently or in combination to provide the ECU with accurate data, ensuring engine efficiency and control.In addition to these examples of sensors, the present invention allows for any other local or remote sensors capable of generating information about the engine's load condition.

[0093] In another particular embodiment, the present invention describes a system where the means for determining the initial condition comprises at least one temperature sensor.

[0094] In an alternative embodiment, the present invention describes a system where pressure and temperature sensors are responsible for monitoring fuel pressure and engine temperature in real time.

[0095] In another alternative embodiment, the present invention describes a system where the control unit 105 performs modeling to determine the ambient temperature before starting.

[0096] Mathematical modeling is understood as the process of representing real-world systems or phenomena through mathematical equations, allowing for the understanding and prediction of their behavior. In the ECU, this modeling is essential for creating algorithms that control the engine in real time, adjusting parameters such as fuel injection, ignition, and air-fuel mixture based on sensor data. These models describe relationships between variables, such as pressure and airflow, allowing the ECU to optimize engine performance, efficiency, and emissions under different operating conditions.

[0097] In an alternative embodiment, the present invention describes a system, wherein said system is applicable to engines with indirect fuel injection.

[0098] Indirect fuel injection (PFI) engines utilize a system where fuel is supplied to the fuel injectors through fuel rails. As can be seen in Figure 1, the fuel rail 102 is a fundamental component in the system, functioning as a pressurized reservoir that distributes fuel uniformly to each fuel injector 101. In PFI engines, fuel is injected into the intake ducts, near the intake valves, where it mixes with air before entering the combustion chamber. The presence of fuel rails ensures that the fuel is delivered at constant and controlled pressures, allowing for uniform atomization by the injectors 101 and, consequently, a homogeneous mixture of air and fuel. fuel. This precise control contributes to good engine performance, greater fuel efficiency and reduced emissions, as well as increasing the reliability of the injection system.

[0099] In an alternative embodiment, the present invention describes a system wherein the control unit 105 comprises a local unit.

[0100] In another alternative embodiment, the present invention describes a system wherein the control unit 105 comprises a remote unit.

[0101] The aforementioned system also includes at least one power stage 106, which is an electronic component responsible for amplifying the control signal received from the system's control unit 105 and converting it into a power signal suitable for driving the fuel pump control units 104. This stage 106 is fundamental for providing the necessary power for the operation of these units, based on the commands issued by the control unit 105 (ECU). In addition, the system has at least one voltage and current monitoring unit 108, which monitors the electrical voltage and current flowing in the fuel system, especially in the power stage 106, providing information on the electrical performance of the system and ensuring that the power supplied is adequate, preventing overloads or electrical failures.Finally, the system includes at least one external source 107, such as a battery, which provides power to the control system, enabling the performance of specific functions.

[0102] Additionally, the present invention discloses an engine equipped with the dynamic fuel injection pressure control system described above, said system performing the method disclosed above.

[0103] Thus, the proposed solution for controlling the pressure of multiple pumps via PWM in PFI engines, in this case, to increase the pressure in synchrony with the engine load, presents a novel and inventive technical effect. This approach deals with the simultaneous control of multiple pumps, requiring dynamic coordination between them and precise pressure adjustment in response to critical engine variables such as load, revolutions per minute (rpm), and airflow. This technical advancement optimizes fuel delivery under high-demand conditions, ensuring improved engine performance and greater energy efficiency.

[0104] Furthermore, the solution addresses specific challenges, such as system stability at high pressures, preventing cavitation in the pumps and ensuring uniform load distribution among them. Using pulse width modulation (PWM), pressure control is performed precisely and dynamically, allowing it to meet high power demands without compromising component integrity or system reliability. This methodology combines operational efficiency with application flexibility, standing out as an advanced solution for modern motors.

[0105] Therefore, the present invention fulfills the role of providing a method for dynamically controlling injected fuel pressure applicable to air-fuel mixture fuel injection systems capable of controlling fuel pump pressure via PWM in PFI engines, specifically to increase pressure, a system that implements said method, and an engine equipped with said system, said system being equipped with at least one fuel pump, preferably, but not necessarily, two or more pumps. This approach provides a number of benefits, such as increased reliability of the pressurization system with redundancy, greater flow flexibility in PFI injectors, and reduced Significant savings in fuel consumption are achieved by reducing the electrical load, minimizing fuel recirculation, reducing the load on the vehicle's engine, and providing the ability to monitor leaks in the system and the health status of the fuel pumps.

Claims

CLAIMS 1. A method for dynamically controlling injected fuel pressure, applicable to fuel injection systems with an air-fuel mixture formed before entering the combustion chamber, characterized by comprising the steps of • determine an initial operating condition of the motor (1); • adjust the injected fuel pressure in the initial operating condition of the engine (2) by controlling the power supplied to at least one fuel pump (104) by pulse width modulation; • monitor the injected fuel pressure in real time (3) by means of at least one pressure sensor (103); • monitor an engine operating condition in real time and compare said real-time engine operating condition with an engine reference condition (4); • adjust the fuel pressure to a pressure different from the fuel pressure injected at start-up (5) as soon as the engine reference condition is reached, • monitor the engine's operating condition in real time (6); • adjust the injected fuel pressure according to the engine operating condition (7) by means of a closed loop; • adjust the opening time (8) of at least one fuel injector (101) so as to operate in synchronous cooperation with the previously adjusted injected fuel pressure; • monitor the injected fuel pressure in real time (9) by means of at least one pressure sensor (103).

2. Method according to claim 1, characterized in that steps 1, 2, 3, 4, 5, 6, 7, 8, 9 are performed subsequently.

3. Method according to claim 1, characterized in that steps 3, 4, 6, 9 are performed continuously.

4. Method according to claim 1, characterized in that steps 3, 4, 6, 9 are performed intermittently.

5. A method according to claim 1, characterized in that the initial operating condition of the motor comprises an operating condition of the motor at an instant prior to the actual operating condition of the motor.

6. Method according to claim 1, characterized in that the initial operating condition of the motor comprises the ambient temperature before starting.

7. Method according to claim 6, characterized in that the ambient temperature before departure is determined by means of at least one temperature sensor.

8. Method according to claim 6, characterized in that the ambient temperature before departure is determined by means of modeling performed by at least one control unit (105).

9. Method according to claim 1, characterized in that the power supplied to the fuel pump (104) is controlled by means of pulse width modulation according to the engine operating condition.

10. Method, according to claim 1, characterized in that the equivalent voltage supplied to the fuel pump (104) is less than or equal to the electrical voltage available in an electrical system to which said pump is associated and is controlled by means of modulation. by pulse width according to an operational limit of said fuel pump (104).

11. Method according to claim 1, characterized in that the fuel pressure is adjusted to a higher pressure than the fuel injected at start-up according to the real-time engine operating condition.

12. Method according to claim 1, characterized in that the opening time of the fuel injector (101) is adjusted according to the previously adjusted injected fuel pressure and the engine operating condition.

13. Method according to claim 1, characterized in that said method operates on at least two fuel pumps (104).

14. Dynamic fuel injection pressure control system that performs the method defined in claims 1 to 13, characterized by comprising • at least one fuel pump (104); • at least one pressure sensor (103); • at least one means of verifying the initial condition; • at least one control unit (105); • at least one fuel injector (101).

15. System according to claim 14, characterized in that it comprises at least two fuel pumps (104).

16. System according to claim 14, characterized in that the control unit (105) is capable of executing the method defined by claims 1 to 13.

17. System according to claim 14, characterized in that the fuel pump (104) is controlled by pulse width modulation.

18. System according to claim 14, characterized in that the adjustment of the injected fuel pressure is carried out by means of a closed loop.

19. System according to claim 14, characterized in that the adjustment of the fuel injector opening time (101) is carried out in cooperation with the previously adjusted injected fuel pressure.

20. System according to claim 14, characterized in that the means for measuring the initial condition comprises at least one engine load sensor.

21. System according to claim 14, characterized in that the means for determining the initial condition comprises at least one temperature sensor.

22. System according to claim 14, characterized in that the pressure and temperature sensors are responsible for monitoring the fuel pressure and engine temperature in real time.

23. System according to claim 14, characterized in that the control unit (105) performs modeling to determine the ambient temperature before starting.

24. System according to claim 14, characterized in that the system is applicable to engines with indirect fuel injection.

25. System according to claim 14, characterized in that the control unit (105) comprises a local unit. • System according to claim 14, characterized in that the control unit (105) comprises a remote unit.

26. Engine characterized by being equipped with a dynamic fuel injection pressure control system defined by claims 14 to 24 that performs the method defined by claims 1 to 13.

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