Device and method for controlling the starting of a port fuel injection (PFI) engine

Abstract

To provide an electronic control device for starting a port fuel injection type engine having an asymmetric crank wheel.SOLUTION: An electronic control device 200 includes one or more interface 210, and receives a crank signal from a crank shaft sensor 215 and a cam signal from a cam shaft sensor 220. A processor 230 transmits a first command, and starts fuel injection to one or more cylinders of a port fuel injection type engine, when detecting at least one of a first state and a second state. The first state includes the discrimination of a falling edge of the crank signal to detect a gap of an asymmetric crank wheel. The second state includes the determination of a specified pattern of the cam signal before detecting a first gap of the asymmetric crank wheel.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for controlling the start-up of a port fuel injection (PFI) engine, and more particularly to rapid start-up of a PFI engine having an asymmetric crank wheel. [Background technology]

[0002] In PFI type engines, fuel is sprayed into the intake ports of the cylinder manifold and the air / fuel mixture is drawn into the cylinder head when the intake valve opens. The air / fuel mixture is compressed and ignited to start the internal combustion engine. The time for starting during cold conditions and normal conditions needs to be reduced as it can affect emissions and fuel economy. To start the engine during cold conditions, a concentrated air / fuel mixture is needed due to the low combustion temperature in the vehicle. Additional fuel is needed to warm up the engine at low temperatures. Therefore, the first cycle is very important during cold starts. Otherwise, it will lead to higher fuel consumption and emission problems.

[0003] Currently, in an injection method called "big bang injection," fuel is pre-injected into all cylinders of the engine simultaneously in a time-based task, even before synchronization by both the crank and camwheel has been achieved, however, it leads to unburned fuel emissions and pollution.

[0004] Patent Document 1 discloses an injection control device for IC engines. This publication discloses detecting a specific gap only in a special type of asymmetric crank wheel and injecting fuel only into one specific cylinder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-207394 A Summary of the Invention [Means for solving the problem]

[0006] The present invention discloses an electronic control for starting a port fuel injection (PFI) type engine having an asymmetric crank wheel. The electronic control includes one or more interfaces and receives a crank signal from a crankshaft sensor and a cam signal from a camshaft sensor. A processor transmits a first command to initiate fuel injection into one or more cylinders of the PFI type engine upon detecting at least one of a first condition and a second condition. The first condition includes determining a falling edge of the crank signal to detect a gap in the crankshaft sensor wheel. The second condition includes determining a particular pattern of the cam signal prior to detecting the first gap in the crankshaft sensor wheel.

[0007] The processor, upon detecting a first condition, sends a first command to initiate fuel injection into all cylinders of the PFI engine. The processor, upon detecting a second condition, detects a top dead center (TDC) of a cylinder of the PFI engine. The processor further, upon detecting the second condition, identifies a particular cylinder that is in an intake stroke. The processor sends the first command to inject fuel into an intake manifold of the particular cylinder that is in an intake stroke. The processor further, upon determining one of a third condition and a fourth condition, sends a second command to fire at least one spark plug of at least one cylinder of the PFI engine. The third condition includes determining a particular pattern of the cam signal after detecting the first condition. The fourth condition includes determining a crank wheel gap using the crank signal after detecting the second condition. The processor, upon detecting the third condition, identifies a cylinder that is in a combustion stroke. The processor sends a second command to ignite the compressed air / fuel mixture in the cylinder during the combustion stroke to start the PFI engine. When the processor determines a fourth condition, it sends a second command to ignite the compressed air / fuel mixture in the particular cylinder.

[0008] A method of controlling starting of a port fuel injection (PFI) engine is also disclosed. The PFI engine includes an asymmetric crank wheel. The method includes receiving a crank signal from a crankshaft sensor and receiving a cam signal from a camshaft sensor. A first command is sent upon detecting at least one of a first condition and a second condition by the processor to initiate fuel injection into one or more cylinders of the PFI engine. The first condition includes determining a falling edge of the crank signal to detect a gap in the asymmetric crank wheel. The second condition includes determining a particular pattern of the cam signal prior to detecting a gap in the asymmetric crank wheel. The first command is sent upon detecting the first condition to initiate fuel injection into all cylinders of the PFI engine. A top dead center (TDC) of the cylinders of the PFI engine is determined upon detecting the second condition.

[0009] A particular cylinder during the intake stroke is determined upon detecting the second condition. A first command is sent to inject fuel into the intake manifold of the cylinder manifold of the particular cylinder during the intake stroke. A second command is sent upon determining at least one of a third condition and a fourth condition to fire at least one spark plug of at least one cylinder of the PFI engine. The third condition includes determining a particular pattern of the cam signal after detecting the first condition. The fourth condition includes determining an asymmetric crank wheel gap using the crank signal after detecting the second condition.

[0010] A cylinder that is in the combustion stroke is identified upon detection of a third condition. A second command is sent to ignite the compressed air / fuel mixture in the cylinder that is in the combustion stroke to start the PFI engine. A second command is sent upon detection of a fourth condition to ignite the compressed air / fuel mixture in the particular cylinder. [Brief description of the drawings]

[0011] An embodiment of the present disclosure will now be described with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 shows a schematic block diagram of a fuel injection system for a port fuel injection (PFI) type engine, in accordance with an embodiment of the present invention. [Diagram 2] FIG. 1 shows a schematic block diagram of an electronic control device for starting a port fuel injection (PFI) engine, according to one embodiment of the present invention. [Diagram 3] 1 shows a schematic diagram of an exemplary asymmetric crank wheel according to one embodiment of the present invention; [Figure 4a] 1 illustrates the patterns of crank signals, cam signals, their interrelationships, and the control of fuel injection and ignition using them in a four-cylinder PFI type engine according to one embodiment of the present invention. [Figure 4b] 1 illustrates the patterns of crank signals, cam signals, their interrelationships, and the control of fuel injection and ignition using them in a four-cylinder PFI type engine according to one embodiment of the present invention. [Diagram 5] 1 illustrates a flow chart of a method for controlling the start of a port fuel injection (PFI) engine, in accordance with one embodiment of the present invention. [Figure 6] 4 shows a flow chart illustrating further steps of a method for controlling the start of a port fuel injection (PFI) engine according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] FIG. 1 shows a schematic block diagram of a fuel injection system for a port fuel injection (PFI) engine, according to one embodiment of the present invention. PFI engine 10 is shown in FIG. 1 as a four-cylinder engine. Air is cleaned by filter 20 and drawn through intake path 30. Fuel from a tank 40 is injected into the intake manifold 50 of the cylinders by respective fuel injectors 60. The air / fuel mixture is drawn inside the cylinders when the intake valves open. An electronic controller 200 of the present invention controls the fuel injection, ignition and other operations of PFI engine 10.

[0013] 2 shows a schematic block diagram of an electronic control unit for starting a port fuel injection (PFI) engine, according to one embodiment of the present invention. The PFI engine 10 includes an asymmetric crank wheel. The electronic control unit 200 includes one or more interfaces 210 to receive signals from various sensors of the vehicle and to send signals and commands to various actuators of the vehicle. The interfaces 210 may take the form of I / O pins. A crankshaft sensor 215 sends a crank signal and a camshaft sensor 220 sends a cam signal to the electronic control unit 200 via the interfaces 210.

[0014] The electronic control unit 200 may be an electronic control unit (ECU), an engine control unit, an engine management system (EMS), etc. The electronic control unit 200 includes a processor 230, which processes received signals from the crankshaft sensor 215 and the camshaft sensor 220. When the processor 230 detects the occurrence of either a first condition or a second condition, it sends a first command to initiate fuel injection into one or more cylinders of the PFI type engine 10. The first condition and the second condition are described in the following paragraphs. The first command may be sent to a fuel injector 240 of the PFI type engine 10 via an interface 210 (i.e., an output interface).

[0015] The first state involves determining a falling edge of the crank signal by the processor 230 to detect a gap in the crank wheel or crankshaft sensor wheel, i.e., asymmetric crank wheel 300. Figures 3(a) and 3(b) show schematic diagrams of two exemplary asymmetric crank wheels 300, according to one embodiment of the present invention. A crank wheel with equally spaced teeth over 360 crank angles and multiple gaps (e.g., 36-2-2, 36-2-2-2, etc.) is referred to as an asymmetric crank wheel 300.

[0016] A crank wheel pattern commonly used in the automotive industry is 36-2-2, 36-2-2-2, where the first number represents the total number of teeth on the wheel. The second and subsequent numbers after the dash "-" indicate the number of gaps (missing teeth) at 360 crank angles. FIG. 3(a) shows an asymmetric crank wheel 300 with "36 teeth" and "2 gaps" 310, where the two gaps are caused by two missing teeth. FIG. 3(b) shows an asymmetric crank wheel 300 with "36 teeth" and "3 gaps" 310, where the three gaps are caused by two missing teeth. The crankshaft sensor 215 detects the gaps 310 of the asymmetric crank wheel 300 by determining the falling edge of the crank signal.

[0017] The second condition includes determining a particular pattern of the cam signal prior to detecting a gap in the asymmetric crank wheel 300. If the processor 30 detects either the first condition or the second condition, it sends a first command to initiate fuel injection into one or more cylinders of the PFI engine 10. For example, the processor 230 sends a first command to activate the fuel injector 240 to initiate fuel injection into the intake manifold 50 of the cylinders of the PFI engine 10.

[0018] When processor 230 detects a second condition (i.e., a particular pattern in the cam signal prior to detecting a gap in the crankshaft sensor signal), processor 230 detects top dead center (TDC) of a cylinder of PFI engine 10. For example, in a multi-cylinder engine, such as a four-cylinder engine, processor 230 determines which of the four cylinders is on its "intake stroke" when processor 230 detects the TDC of the cylinder. Processor 230 sends a first command to inject fuel into intake manifold 50 of the cylinder manifold of that particular cylinder on its intake stroke.

[0019] 4a and 4b show patterns of crank signals, cam signals, and their interrelationships, and their use in controlling fuel injection and ignition in a four-cylinder PFI engine 10, according to one embodiment of the present invention. When the processor 230 determines a first condition (FirC) (i.e., a falling edge (Gap 1) of the crank signal), as shown in FIG. 4a, the processor 230 initiates fuel injection into one or more cylinders of the PFI engine 10.

[0020] 4b, processor 230 next detects TDC of cylinder 1 when it determines a second condition (SC) (i.e., a particular pattern of the cam signal). Processor 230 then determines that cylinder 3 is on the "intake stroke" based on the cam signal pattern. Processor 230 sends a first command to the fuel injector (60, 240) for cylinder 3 to begin injecting fuel into the intake manifold 50 for cylinder 3.

[0021] Additionally, if the processor 230 subsequently detects either the third condition or the fourth condition, it sends a second command to fire the spark plugs 250 of one or more cylinders of the PFI engine 10. The third and fourth conditions are described in the following paragraphs.

[0022] If the processor 230 determines a particular pattern of the cam signal following detection of the first condition, it is referred to as a third condition. Upon detecting the third condition, the processor 230 determines which cylinder is in the combustion stroke. The processor 230 sends a second command to ignite the compressed air / fuel mixture in the cylinder in the combustion stroke and start the PFI engine 10.

[0023] For example, as shown in Figure 4a, a third state (TC) is detected by processor 230 by detecting a particular pattern in the cam signal. This state is represented as S0 in Figure 4a. Processor 230 determines that cylinder 2 is in the "combustion stroke" and sends a second command to spark plug 50 of cylinder 2 to initiate ignition.

[0024] Similarly, if after detecting the second condition, processor 230 uses the crank signal to determine the gap of crank wheel 300, it is referred to as a fourth condition. The gap of crank wheel 300 is determined by detecting the falling edge of the crank signal. Upon determining the fourth condition, processor 230 sends a second command to ignite the compressed air / fuel mixture in a particular cylinder.

[0025] 4b, processor 230 detects a gap in crank wheel 300 using the fourth state (FC), i.e., the falling edge / gap (Gap 1) of the crank signal. Processor 230 sends a second command to spark plug 250 to ignite the compressed air / fuel mixture in cylinder 3 during the "combustion stroke."

[0026] The processor 230 allows for a very quick start of the PFI engine 10 compared to existing approaches, reducing harmful particulate and NOx emissions. Since fuel injection is initiated at the right time and speed, scenarios where unburned fuel reaches the exhaust gases do not occur, thus avoiding auto-fires and explosions in the exhaust path. An optimal amount of fuel is injected into the cylinders, which therefore results in better combustion. Optimal cylinder temperatures are maintained by avoiding misfires in cold start scenarios. The electronic control improves the overall system operation compared to existing PFI systems in normal and cold start conditions. The electronic control 200 allows for faster and more efficient injection compared to "big bang type injection". It allows for a quicker start of the engine 10. The present invention is applicable to both start-stop based scenarios and cold start scenarios. Furthermore, it is applicable to all types of asymmetric crank wheels and is not limited to only a special type of asymmetric crank wheel.

[0027] 5 shows a flow chart of a method for controlling the start of a port fuel injection (PFI) engine, according to one embodiment of the present invention. The method includes receiving, by processor 230, a crank signal from crankshaft sensor 215 and a cam signal from camshaft sensor 220 (step 500). Processor 230 may be a microprocessor of electronic control device 200, such as an ECU, EMS, or engine control unit. Processor 230 analyzes the received signals and detects the occurrence of a first condition at step 510 or detects the occurrence of a second condition at step 520. At step 530, a first command is sent to fuel injector 240 to initiate fuel injection into one or more cylinders of PFI engine 10 upon detection by processor 230 of either the first condition or the second condition.

[0028] The first state includes determining a falling edge of the crank signal to detect a gap in the crankshaft sensor wheel, i.e., the asymmetric crank wheel 300. The second state includes determining a particular pattern of the cam signal prior to detecting the first gap in the asymmetric crank wheel 300. A first command is sent upon detecting the first state to initiate fuel injection into one or more cylinders of the PFI engine 10. A top dead center (TDC) of a cylinder of the PFI engine 10 is determined upon detecting the second state. A particular cylinder during its intake stroke is determined upon detecting the second state. A first command is sent to inject fuel into the intake manifold 50 of a particular cylinder during its intake stroke.

[0029] 6 shows a flow chart illustrating further steps of a method for controlling the starting of a port fuel injection (PFI) engine according to an embodiment of the present invention. The PFI engine 10 includes an asymmetric crank wheel 300. Following detection of either the first condition or the second condition, the processor 230 analyzes the crank and cam signals in step 600. The processor 230 checks for the occurrence of either a third condition or a fourth condition in steps 610 and 620, respectively. A second command is sent in step 630 upon determining either the third condition or the fourth condition to fire at least one spark plug 250 of at least one cylinder of the PFI engine 10.

[0030] The third state involves determining a particular pattern of the cam signal after detecting the first state, and the fourth state involves determining the gap of the crank wheel 300 using the crank signal after detecting the second state.

[0031] A cylinder that is in the combustion stroke is identified upon detection of a third condition, and a second command is sent to ignite the compressed air / fuel mixture in the cylinder that is in the combustion stroke to start the PFI engine 10. A second command is sent upon detection of a fourth condition to ignite the compressed air / fuel mixture in the particular cylinder.

[0032] The method for controlling the start of the PFI type engine 10 is simple and does not require complex modifications for implementation. The method is effective in improving the start speed during normal and cold conditions and also controls pollution. Since the fuel injection is initiated at the proper time and speed, the scenario where unburned fuel reaches the exhaust path does not occur, thus avoiding auto-fire and explosion in the exhaust path. An optimal amount of fuel is injected into the cylinder, thus resulting in better combustion. The method avoids misfire during cold start scenarios. The present invention may be applicable to engines with any type of asymmetric crank wheel. The present invention is much superior to "big bang type injection" in terms of speed and efficiency. It allows for a quicker start of the engine. The present invention is applicable to both start-stop based scenarios and cold start scenarios.

[0033] It should be understood that the embodiments described in the above specification are illustrative only and are not intended to limit the scope of the invention. Many such embodiments and other modifications and variations of the embodiments described herein are contemplated. The scope of the invention is limited only by the claims. [Explanation of symbols]

[0034] 10: Port fuel injection (PFI) engine 20: Filter 30: Intake path 40: Tank 50: Intake manifold 60: Fuel injector 200: Electronic control device 210: Interface 215: Crankshaft sensor 220: Camshaft sensor 230: Processor 240: Fuel injector 250: Spark plug 300: Asymmetric crank wheel 310: Gap

Claims

1. An electronic control device (200) for starting a port fuel injection (PFI) type engine (10), wherein the PFI type engine (10) includes an asymmetric crankwheel (300), the electronic control device (200) comprises, at least one interface (210) for receiving a crank signal from a crankshaft sensor (215) and a cam signal from a camshaft sensor (220), a processor (230) that transmits a first command to start fuel injection into at least one cylinder of the PFI type engine (10) when in at least one of a first state and a second state, the first state includes a state in which the processor (230) discriminates a rising edge of the crank signal and detects a gap of the asymmetric crankwheel (300), and the second state includes a state in which the processor (230) detects a specific pattern of the cam signal before detecting the gap of the asymmetric crankwheel (300), the processor (230) further transmits a second command to ignite at least one spark plug (250) of the at least one cylinder of the PFI type engine (10) when in at least one of a third state and a fourth state, the third state includes a state in which the processor (230) detects a specific pattern of the cam signal after the first state, the fourth state includes a state in which the processor (230) detects a gap of the asymmetric crankwheel (300) based on the crank signal after detecting the gap of the asymmetric crankwheel (300) after detecting a specific pattern of the cam signal during the second state, Electronic control device (200)

2. The electronic control device (200) according to claim 1, wherein the processor (230) transmits the first command to start fuel injection into all cylinders of the PFI type engine (10) when in the first state.

3. The electronic control device (200) according to claim 1, wherein the processor (230) detects a top dead center (TDC) of a cylinder of the PFI type engine (10) when in the second state.

4. The electronic control device (200) according to claim 3, wherein when the processor (230) detects the top dead center (TDC), it discriminates a specific cylinder during the intake stroke.

5. The electronic control device (200) according to claim 4, wherein the processor (230) transmits a first command to inject fuel into the intake manifold (50) of a specific cylinder during the intake stroke.

6. The electronic control device (200) according to any one of claims 1 to 5, wherein when in the third state, the processor (230) discriminates a specific cylinder during the combustion stroke.

7. The electronic control device (200) according to claim 6, wherein the processor (230) transmits the second command to ignite the compressed air / fuel mixture in a specific cylinder during the combustion stroke to start the PFI type engine (10).

8. The electronic control device (200) according to claim 1, wherein when in the fourth state, the processor (230) transmits the second command to ignite the compressed air / fuel mixture in a specific cylinder during the combustion stroke.

9. A method for controlling the start of a port fuel injection (PFI) type engine (10), wherein the PFI type engine (10) includes an asymmetric crankwheel (300), The method includes: Receiving, by a processor (230), a crank signal from a crankshaft sensor (215) and a cam signal from a camshaft sensor (220); When in at least one of a first state and a second state, the processor (230) transmits a first command to start fuel injection into at least one cylinder of the PFI type engine (10); When in at least one of a third state and a fourth state, the processor (230) transmits a second command to ignite at least one spark plug (250) of the at least one cylinder of the PFI type engine (10), The first state is a state in which the processor (230) discriminates a rising edge of the crank signal and detects a gap of the asymmetric crankwheel (300); The second state is a state in which the processor (230) detects a specific pattern of the cam signal before detecting the first gap of the asymmetric crankwheel (300). The third state is a state in which the processor (230) detects a specific pattern of the cam signal after the first state. The fourth state is a state in which, after detecting a specific pattern of the cam signal at the time of detection of the second state and after detecting the gap of the asymmetric crankwheel (300), the processor (230) detects the gap of the asymmetric crankwheel (300) based on the crank signal. Claim 10 The method according to claim 9, wherein in the case of the first state, the first command is transmitted to start fuel injection into all cylinders of the PFI engine (10). Claim 11 The method according to claim 9, wherein the top dead center (TDC) of a cylinder of the PFI engine (10) is detected in the case of the second state. Claim 12 The method according to claim 11, wherein a specific cylinder during the intake stroke is determined to detect the TDC. Claim 13 The method according to claim 12, wherein the first command is transmitted to inject fuel into the intake manifold (50) of the cylinder manifold of a specific cylinder during the intake stroke. Claim 14 The method according to any one of claims 9 to 13, wherein a specific cylinder during the combustion stroke is determined in the case of the third state. Claim 15 The method according to claim 14, wherein the second command is transmitted to ignite the compressed air / fuel mixture in a specific cylinder during the combustion stroke to start the PFI engine (10). Claim 16 The method according to claim 9, wherein the second command is transmitted in the case of the fourth state to ignite the compressed air / fuel mixture in a specific cylinder during the combustion stroke.

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