Dual fuel injection system control

Abstract

A system for fuel injection includes a main fuel injection system configured to inject fuel into a cylinder of an internal combustion engine using a first injection technique and a supplemental fuel injection system configured to inject fuel into the cylinder according to a second injection technique, the second injection technique is different from the first injection technique. The system also includes a controller configured to monitor a parameter of a fuel pump connected to the main fuel injection system and the supplemental fuel injection system, and to control the supplemental fuel injection system based on the parameter being greater than or equal to a parameter threshold. A ratio of a first fuel volume injected by the supplemental fuel injection system to a second fuel volume injected by the primary fuel injection system during an engine stroke is controlled.

Description

Technical Field

[0001] This disclosure relates to the field of engine systems, and more specifically, to fuel injection in engine systems. Background Technology

[0002] The fuel injection system uses fuel injectors to inject fuel into the engine. Fuel injection is typically controlled by the engine control module (ECM) or other controllers. Vehicles may include one or more of various types of fuel injectors, such as port fuel injectors and / or direct fuel injectors. During vehicle operation, it is important to keep fuel injection parameters, such as flow rate and injection volume, within the capabilities of the vehicle hardware, including the fuel pump. Summary of the Invention

[0003] In one exemplary embodiment, the system for fuel injection includes a main fuel injection system and a supplementary fuel injection system. The main fuel injection system is configured to inject fuel into the cylinders of an internal combustion engine using a first injection technique, and the supplementary fuel injection system is configured to inject fuel into the cylinders according to a second injection technique different from the first injection technique. The system also includes a controller configured to monitor parameters of fuel pumps connected to the main fuel injection system and the supplementary fuel injection system, and, based on the parameters being greater than or equal to a parameter threshold, control the ratio of the first fuel volume injected by the supplementary fuel injection system to the second fuel volume injected by the main fuel injection system during an engine stroke.

[0004] In addition to one or more features described herein, the main fuel injection system includes a direct injector having a first size, and the supplemental fuel injection system includes a direct injector having a second size, which is different from the first size.

[0005] In addition to one or more features described herein, the main fuel injection system is a direct injection system, and the supplementary fuel injection system is an inlet fuel injection system.

[0006] In addition to one or more features described herein, the parameter is the fuel intake volume related to the amount of fuel drawn in by the fuel pump.

[0007] In addition to one or more features described herein, the parameter is the average fuel intake volume of the fuel pump over multiple engine strokes.

[0008] In addition to one or more features described herein, the controller is configured to: operate the internal combustion engine in a normal mode, in which fuel injection is performed using a first value of the ratio; and operate the internal combustion engine in a supplementary mode, in which fuel injection is performed using a second value of the ratio, selecting the second value of the ratio to reduce the parameter below the parameter threshold.

[0009] In addition to one or more features described herein, fuel injection is performed solely by the main fuel injection system in normal mode, and fuel injection in supplementary mode is performed solely by the supplementary fuel injection system or by a combination of the main fuel injection system and the supplementary fuel injection system.

[0010] In addition to one or more features described herein, the controller is configured to determine parameters during supplementary mode and compare the determined parameters with parameter thresholds.

[0011] In addition to one or more features described herein, the controller is configured to adjust the air flow delivered to the cylinder during the supplementary mode based on a determined parameter being greater than or equal to a parameter threshold.

[0012] In another exemplary embodiment, a method of operating an internal combustion engine includes supplying a fuel-air mixture to the internal combustion engine by injecting fuel into the cylinders of the internal combustion engine, said injection being performed by at least one of a main fuel injection system and a supplementary fuel injection system, said main fuel injection system being configured to inject fuel using a first injection technique, and said supplementary fuel injection system being configured to inject fuel using a second injection technique different from the first injection technique. The method further includes monitoring parameters of fuel pumps connected to the main fuel injection system and the supplementary fuel injection system, and, based on said parameters being greater than or equal to a parameter threshold, controlling the ratio of a first volume of fuel injected by the supplementary fuel injection system to a second volume of fuel injected by the main fuel injection system during an engine stroke.

[0013] In addition to one or more features described herein, the main fuel injection system includes a direct injector having a first size, and the supplemental fuel injection system includes a direct injector having a second size, which is different from the first size.

[0014] In addition to one or more features described herein, the main fuel injection system is a direct injection system, and the supplementary fuel injection system is an inlet fuel injection system.

[0015] In addition to one or more features described herein, the parameter is the fuel intake volume related to the amount of fuel drawn in by the fuel pump.

[0016] In addition to one or more features described herein, the internal combustion engine operates in a normal mode, in which fuel injection is performed using a first value of the ratio; and the internal combustion engine operates in a supplementary mode, in which fuel injection is performed using a second value of the ratio, the second value of the ratio being selected to reduce the parameter below a parameter threshold.

[0017] In addition to one or more features described herein, fuel injection is performed solely by the main fuel injection system in normal mode, and fuel injection in supplementary mode is performed solely by the supplementary fuel injection system or a combination of the main fuel injection system and the supplementary fuel injection system.

[0018] In addition to one or more features described herein, the method further includes determining the parameter during the supplementary mode, comparing the determined parameter with the parameter threshold, and adjusting the airflow to the cylinder based on the determined parameter being greater than or equal to the parameter threshold.

[0019] In yet another exemplary embodiment, the vehicle system includes an internal combustion engine and a fuel system, the fuel system including a main fuel injection system and a supplementary fuel injection system. The main fuel injection system is configured to inject fuel into cylinders of the internal combustion engine using a first injection technique, and the supplementary fuel injection system is configured to inject fuel into cylinders using a second injection technique different from the first injection technique. The vehicle system also includes a controller configured to monitor parameters of fuel pumps connected to the main fuel injection system and the supplementary fuel injection system, and, based on the parameters being greater than or equal to a parameter threshold, control the ratio of a first volume of fuel injected by the supplementary fuel injection system to a second volume of fuel injected by the main fuel injection system during an engine stroke.

[0020] In addition to one or more features described herein, the controller is configured to: operate the internal combustion engine in a normal mode, in which a first value of the ratio is used to perform fuel injection; and operate the internal combustion engine in a supplementary mode, in which a second value of the ratio is used to perform fuel injection, selecting the second value of the ratio to reduce the parameter below a parameter threshold.

[0021] In addition to one or more features described herein, fuel injection is performed solely by the main fuel injection system in normal mode, and fuel injection in supplementary mode is performed solely by the supplementary fuel injection system or by a combination of the main fuel injection system and the supplementary fuel injection system.

[0022] In addition to one or more features described herein, the controller is configured to determine the parameter during the supplementary mode, compare the determined parameter with the parameter threshold, and adjust the airflow to the cylinder based on the determined parameter being greater than or equal to the parameter threshold.

[0023] The above-described features and advantages, as well as other features and advantages, of this disclosure will become apparent when taken in conjunction with the accompanying drawings and the following detailed description. Attached Figure Description

[0024] Other features, advantages, and details appear by way of example only in the following detailed description, which is described in detail with reference to the accompanying drawings, wherein:

[0025] Figure 1 This is a top view of a vehicle according to an exemplary embodiment;

[0026] Figure 2 This is a cross-sectional view of an engine including a fuel injection system according to an exemplary embodiment;

[0027] Figure 3 These are flowcharts depicting various aspects of a method for controlling an internal combustion engine according to exemplary embodiments; and

[0028] Figure 4 A computer system according to an exemplary embodiment is described. Detailed Implementation

[0029] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or use. It should be understood that throughout the drawings, corresponding reference numerals denote the same or corresponding parts and features.

[0030] According to an exemplary embodiment, a fuel injection system and associated method for an internal combustion engine are provided. One embodiment of the propulsion system includes a main fuel injection system and a supplementary fuel injection system. A controller is configured to monitor one or more components of the propulsion system, such as a fuel pump, and compare parameters related to fuel injection and / or propulsion (e.g., pump intake volume) with parameter thresholds (e.g., maximum pump capacity or maximum intake volume).

[0031] Based on parameters being greater than or equal to a parameter threshold, the controller switches the engine from normal mode to supplementary mode. In normal mode, fuel injection is provided solely by the main fuel injection system, or fuel is injected using an initial ratio of supplementary fuel injection to main fuel injection. In supplementary mode, the controller activates the supplementary fuel injection system and / or adjusts the ratio so that fuel injection can continue without exceeding the capacity of the fuel pump and / or other components.

[0032] The embodiments described herein present numerous advantages and technical effects. These embodiments provide improvements in the efficiency and performance of internal combustion engines. For example, they ensure a sufficient supply of fuel under all conditions while keeping fuel system components, such as high-pressure fuel pumps, within their operating limits. Furthermore, the embodiments allow for fuel systems that are too small for all environmental conditions (e.g., allowing for smaller fuel pumps compared to existing fuel injection systems). By allowing for smaller fuel systems, emissions are improved and the resources required to construct the fuel system and camshaft assembly are reduced.

[0033] The embodiments are not limited to use with any particular vehicle and can be applied to a variety of contexts. For example, the embodiments can be used with automobiles, trucks, construction equipment, power tools, motorcycles, boats, aircraft, and / or any other device or system that includes one or more fuel-injected engines.

[0034] Figure 1 An embodiment of a motor vehicle 10 is shown, which includes a body 12 that at least partially defines a passenger compartment 14. The body 12 also supports various vehicle subsystems, including a propulsion system 16 and other subsystems to support the functions of the propulsion system 16 and other vehicle components, such as braking subsystems, suspension systems, steering subsystems, etc. If the vehicle 10 is a combustion engine vehicle or a hybrid electric vehicle, other vehicle components include a fuel injection subsystem, an exhaust subsystem, etc.

[0035] For example, vehicle 10 is a hybrid vehicle, wherein propulsion system 16 includes an internal combustion engine 18 for applying torque and other components for supporting engine operation, such as a cooling system 20. Engine 18 is connected to a transmission system 22 for controlling the transmission of torque from engine 18 to a front drive shaft 24 connected to the front wheels 26. Propulsion system 16 may also include an electric drive system comprising at least one electric motor 28 connected to a high-voltage (HV) battery pack 30.

[0036] Propulsion system 16 is not limited to Figure 1 The configuration shown is possible because any number of propulsion devices can be present. For example, vehicle 10 may include an electric motor and / or an internal combustion engine (in addition to or in place of engine 18 and electric motor 28) connected to the rear drive axle 32 and the rear wheels 34.

[0037] It includes one or more processing devices to control the operation of the propulsion system 16. In one embodiment, a controller 40, such as an engine control unit (ECU), is configured to receive torque requests and control the engine 18.

[0038] Vehicle 10 also includes a computer system 50, which includes one or more processing units 52 and a user interface 54. The computer system 50 can communicate with controller 40 (e.g., ECU) and / or other processors, for example, to provide commands to it in response to user input (e.g., torque commands). Various processing devices, modules, and units can communicate with each other via communication devices or systems such as Controller Area Network (CAN) or Transmission Control Protocol (TCP) buses.

[0039] Figure 2 An embodiment of a propulsion system 16 is depicted. In this embodiment, the propulsion system 16 includes a fuel injection system having a main injection system and an auxiliary or supplementary injection system. The main injection system and the supplementary injection system may use the same type of fuel injection or different types of fuel injection.

[0040] For example, engine 18 is a spark-ignition engine comprising multiple cylinders 60, each cylinder 60 receiving an air-fuel mixture for combustion. Air may be received via intake manifold 62 and controlled by a throttle valve or valve 64, which may be controlled by controller 40 to regulate the airflow entering intake manifold 62 (indicated by arrow A).

[0041] Each cylinder 60 is connected to a spark plug 66 and an intake valve 68 for receiving air or an air-fuel mixture. The intake valve position is adjusted via an intake camshaft 70. An exhaust valve 72 is also connected to each cylinder 60 for removing combustion exhaust (indicated by arrow E).

[0042] The engine crankshaft (not shown) rotates at engine speed or a rate proportional to engine speed. A crankshaft sensor 74 may be included to allow the controller 40 to determine the position of the crankshaft during engine operation.

[0043] Engine 18 includes a fuel system with two fuel injection systems. The fuel injection systems are configured to supply fuel to cylinder 60 using different injection technologies. The injection systems are in fluid communication with fuel tank 76 and high-pressure pump 78.

[0044] In this embodiment, the fuel system includes a main fuel injection system 80 and a supplementary fuel injection system 90. Each fuel injection system is configured to inject fuel using a different injection technology. For example, the fuel injection systems may use the same type of injection (e.g., direct injection or port injection) but have different parameters, such as different injector sizes that allow for different flow rates.

[0045] like Figure 2As shown, the main fuel injection system 80 is configured as a direct injection (DI) system, wherein fuel is injected directly into each cylinder 60 via direct fuel injection technology. The supplementary fuel injection system 90 is configured as a port fuel injection (PFI) system, wherein fuel is injected via PFI technology. In this example, PFI technology includes injecting fuel into the intake manifold 62 to mix with air before the air-fuel mixture is delivered to each cylinder 60.

[0046] The primary fuel injection system 80 includes a primary fuel rail 82 in fluid communication with a direct injector 84 coupled to each cylinder 60. The primary fuel rail 82 is configured to allow pressurized fuel to flow from the pump 78 to each direct injector 84. A primary fuel valve 86 can be controlled by a controller 40 to regulate the fuel flow rate.

[0047] The supplemental fuel injection system 90 includes a supplemental fuel rail 92 configured to allow pressurized fuel to flow from the pump 78 to the intake injector 94 associated with each cylinder 60. A supplemental fuel valve 96 may be controlled by a controller 40 to regulate the flow rate of fuel through the fuel rail 92 (and / or activate and deactivate the supplemental fuel injection system 90).

[0048] It should be noted that the main fuel valve 86 and the supplemental fuel valve 96 can be operated to adjust the relative amount of fuel supplied by each injection system, and / or as a switch operation to activate or deactivate one of the injection systems. For example, the main fuel valve 86 and / or the supplemental fuel valve 96 can be controlled to provide a ratio of the fuel volume supplied by the supplemental fuel injection system 90 (supplemental fuel volume) to the fuel volume supplied by the main fuel injection system 80 (main fuel volume).

[0049] Engine 18 can operate according to multiple fuel injection modes. For example, engine 18 can operate in a normal mode, where fuel injection is performed using an initial ratio of supplementary fuel volume (e.g., injected via inlet fuel injection) to main fuel volume (e.g., injected via direct injection). This ratio is referred to as the "injection ratio" and is defined as the ratio of the fuel volume injected by supplementary fuel injection system 90 during the stroke to the fuel volume injected by main fuel injection system 80 during the stroke.

[0050] The normal mode can use only the main fuel injection (i.e., the ratio is zero), or a selected proportion of the total fuel volume injected by supplementary injection. For example, in normal mode, valve 96 is closed and valve 86 is open, so that fuel is injected only via the main fuel injection system 80. In another example, the normal mode uses an initial or first injection ratio, and the supplementary mode uses a second injection ratio different from the initial or first injection ratio.

[0051] Figure 3 An embodiment of a method 100 for controlling an internal combustion engine is shown. Aspects of method 100 may be executed by a controller 40 or other suitable processing device.

[0052] For illustrative purposes, combined with Figure 2 The method 100 describes the engine 18 and fuel injection system. Embodiments are not limited thereto, as method 100 can be performed in conjunction with any suitable vehicle or drive system having dual injection capabilities.

[0053] Method 100 includes multiple steps or stages represented by boxes 101-108. Method 100 is not limited to the number or order of the steps, because some steps represented by boxes 101-108 may be performed in a different order than that described below, or fewer than all steps may be performed.

[0054] At box 101, vehicle 10 is in operation, and engine 18 is running. Engine 18 is in normal mode at this time. In normal mode, supplementary fuel injection system 90 is inactive, and fuel injection is performed solely by main fuel injection system 80. Alternatively, in normal mode, both injection systems are active and operate according to an initial injection ratio. The initial injection ratio is determined based on factors such as engine speed and load.

[0055] At box 102, pump 78 (and / or engine 18 or other components of the fuel system) is monitored to determine if triggering conditions are met. For example, factors such as temperature changes, load changes, and spark timing changes are monitored and compared to system limits.

[0056] Controller 40 determines whether the factor is within the system limits. If the factor is within the system limits, method 100 terminates at block 108, and fuel injection continues according to the normal mode. If the factor meets or exceeds the system limits, the trigger condition is met, and method 100 proceeds to block 103.

[0057] At box 103, if a trigger condition is met (i.e., a system or hardware limitation is met), a parameter related to fuel injection and / or engine operation is monitored and compared to a parameter threshold. This parameter may be engine-related, such as rotational speed or torque. In one embodiment, this parameter is related to the fuel flow to engine 18.

[0058] When determining parameters, they are compared with parameter thresholds. If a parameter does not meet or exceeds a parameter threshold, the normal mode is maintained.

[0059] For example, pump 78 is monitored to measure or estimate the volumetric demand (i.e., the volume of fuel drawn in) for each stroke of pump 78. The estimated volumetric demand is then compared to the maximum volumetric capacity of pump 78.

[0060] In one embodiment, the average demand is calculated over multiple strokes. This averaging calculation is useful when the number of valve discs in pump 78 does not match the number of cylinders 60.

[0061] At box 104, controller 40 determines whether a parameter (e.g., the estimated volume requirement or average volume requirement of the stroke) is still greater than or equal to a parameter threshold. If the parameter is no longer greater than or equal to the parameter threshold, method 100 terminates at box 108, and fuel injection continues according to the normal mode.

[0062] At box 105, if the parameter is still greater than or equal to the parameter threshold (e.g., the volume requirement still meets or exceeds the maximum volume capacity), the engine 18 is placed in supplementary mode, in which the ratio is adjusted (or the main fuel injection is disabled and the supplementary fuel injection is enabled).

[0063] In one implementation, the initial injection ratio is adjusted. For example, the average volume requirement is used to calculate the new injection ratio. The initial ratio is adjusted to achieve the new injection ratio by increasing the relative fuel volume of the fuel injected by the supplemental fuel injection system 90.

[0064] At box 106, controller 40 determines whether parameters continue to meet or exceed parameter thresholds when a new injection ratio is applied. For example, controller 40 continues fuel injection using the new injection ratio and measures the volume demand of pump 78.

[0065] If the new injection ratio results in the volume requirement (or other parameters) being within the parameter threshold, then method 100 ends and fuel injection continues according to the new injection ratio.

[0066] At box 107, if the volume demand or other parameters still meet or exceed parameter thresholds, controller 40 restricts airflow (e.g., via a control valve or throttle valve 64). Controller 40 continues to monitor engine 18 and, if fuel demand drops below the parameter thresholds, returns airflow to its previous level. If fuel demand drops further, engine 18 can return to normal mode.

[0067] Figure 4 Examples of embodiments of a computer system 140 are shown, which can perform various aspects of the embodiments described herein. The computer system 140 includes at least one processing means 142, which generally includes one or more processors for performing various aspects of the image acquisition and analysis methods described herein.

[0068] The components of computer system 140 include processing device 142 (such as one or more processors or processing units), memory 144, and bus 146, which couples various system components, including system memory 144, to processing device 142. System memory 144 may be a non-transitory computer-readable medium and may include various computer system-readable media. Such media may be any available media accessible by processing device 142, and includes volatile and non-volatile media as well as removable and non-removable media.

[0069] For example, system memory 144 includes non-volatile memory 148 such as read-only memory (ROM), and may also include volatile memory 150 such as random access memory (RAM) and / or cache memory. Computer system 140 may also include other removable / non-removable, volatile / non-volatile computer system storage media.

[0070] System memory 144 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, system memory 144 stores various program modules that generally perform the functions and / or methods of the embodiments described herein. One or more modules 152 may be included to perform the functions discussed herein. System 140 is not limited thereto, as other modules may be included. As used herein, the term "module" means that it may include application-specific integrated circuits (ASICs), electronic circuitry, processing circuitry of a processor (shared, dedicated, or group) and memory executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the described functions.

[0071] The processing device 142 can also communicate with one or more external devices 156, which may be a keyboard, a pointing device, and / or any device that enables the processing device 142 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Communication with various devices may occur via input / output (I / O) interfaces 164 and 165.

[0072] The processing device 142 can also communicate via network adapter 168 with one or more networks 166, such as a local area network (LAN), a general wide area network (WAN), a bus network, and / or a public network (e.g., the Internet). It should be understood that, although not shown, other hardware and / or software components may be used in conjunction with the computer system 140. Examples include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archiving storage systems.

[0073] The term “a” does not indicate a limitation of quantity, but rather that at least one of the referenced items is present. Unless the context clearly indicates otherwise, the term “or” means “and / or”. Throughout the specification, reference to “aspect” means that a particular element described in connection with that aspect (e.g., a feature, structure, step, or characteristic) is included in at least one aspect described herein and may or may not be present in other aspects. Furthermore, it should be understood that the described elements may be combined in any suitable manner in the aspects.

[0074] When an element, such as a layer, film, region, or substrate, is referred to as being “on” another element, it can be directly on the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being “directly” on another element, there are no intermediate elements present.

[0075] Unless otherwise specified herein, all test standards are the most recent standards in effect up to the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which a test standard appears.

[0076] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0077] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and elements can be substituted with equivalents without departing from its scope. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of this disclosure without departing from the basic scope of this disclosure. Therefore, this disclosure is intended to be limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A system for fuel injection, comprising: A main fuel injection system configured to inject fuel into the cylinders of an internal combustion engine using a first injection technology; A supplemental fuel injection system configured to inject fuel into the cylinder according to a second injection technique, the second injection technique being different from the first injection technique; and A controller configured to monitor parameters of fuel pumps connected to the main fuel injection system and the supplemental fuel injection system, and based on the parameters being greater than or equal to a parameter threshold, control the ratio of a first fuel volume injected by the supplemental fuel injection system to a second fuel volume injected by the main fuel injection system during an engine stroke.

2. The system of claim 1, wherein the main fuel injection system includes a direct injector having a first size, and the supplemental fuel injection system includes a direct injector having a second size, the second size being different from the first size.

3. The system according to claim 1, wherein, The main fuel injection system is a direct injection system, and the supplementary fuel injection system is an intake manifold fuel injection system.

4. The system according to claim 1, wherein, The parameter is the fuel intake volume, which is related to the amount of fuel drawn in by the fuel pump.

5. The system according to claim 1, wherein, The parameter is the average fuel intake volume that enters the fuel pump over multiple engine strokes.

6. The system according to claim 1, wherein, The controller is configured to: operate the internal combustion engine in a normal mode, in which fuel injection is performed using a first value of the ratio; and operate the internal combustion engine in a supplementary mode, in which fuel injection is performed using a second value of the ratio, wherein the second value of the ratio is selected to reduce the parameter below the parameter threshold.

7. The system according to claim 6, wherein, The fuel injection in the normal mode is performed only by the main fuel injection system, and the fuel injection in the supplementary mode is performed only by the supplementary fuel injection system or by a combination of the main fuel injection system and the supplementary fuel injection system.

8. The system according to claim 6, wherein, The controller is configured to determine the parameter during the supplementary mode and compare the determined parameter with the parameter threshold.

9. The system according to claim 8, wherein, The controller is configured to adjust the air flow delivered to the cylinder during the supplemental mode based on a determined parameter being greater than or equal to a parameter threshold.

10. A method of operating an internal combustion engine, comprising: A fuel-air mixture is supplied to the internal combustion engine by injecting fuel into the cylinders of the internal combustion engine. The injection is performed by at least one of a main fuel injection system and a supplementary fuel injection system, wherein the main fuel injection system is configured to inject fuel using a first injection technology and the supplementary fuel injection system is configured to inject fuel using a second injection technology, which is different from the first injection technology. Monitor the parameters of the fuel pumps connected to the main fuel injection system and the supplemental fuel injection system; and Based on the parameter being greater than or equal to the parameter threshold, the ratio of the first volume of fuel injected by the supplementary fuel injection system to the second volume of fuel injected by the main fuel injection system during the engine stroke is controlled.

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