WO2024052953A1

WO2024052953A1 - Electronic control device

Info

Publication number: WO2024052953A1
Application number: PCT/JP2022/033236
Authority: WO
Inventors: 茂美大野; 芳国倉島; 貞人堀内
Original assignee: 日立Astemo株式会社
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2024-03-14

Abstract

The present invention provides an electronic control device that is able to prevent valve opening failure of an injector when an abnormality occurs in a fuel pressure sensor that detects the pressure of a fuel supplied by the injector, and prevent the engine from stopping or prevent a reduction in rotation speed. This electronic control device (ECU5) comprises a target fuel pressure calculating unit (501), a fuel pressure acquiring unit (502), a failure detecting unit (503), a failure confirming unit (504), an abnormality detecting unit (505), an abnormality confirming unit (506), and a drive current setting unit (507). The failure confirming unit (504) confirms a fuel pressure sensor failure when the detection of a sensor failure has continued for longer than a first time period. The abnormality confirming unit (506) confirms a sensor value abnormality when the detection of a detection value abnormality has continued for longer than a second time period. The drive current setting unit (507) sets a provisional drive current based on a fuel pressure detection value detected before the fuel pressure sensor failure and the detection value abnormality were detected, when the drive current of the injector over a period from the detection of the fuel pressure sensor failure until the first time period has elapsed or from the detection of the detection value abnormality until the second time period has elapsed.

Description

electronic control unit

The present disclosure relates to an electronic control device.

Inventions relating to a high-pressure fuel supply device for an internal combustion engine, a fuel injection control device, and a fuel supply control device for an internal combustion engine are conventionally known (see Patent Documents 1 to 3 below).

The high-pressure fuel supply device for an internal combustion engine described in Patent Document 1 below includes a high-pressure pump that pressurizes fuel transferred from a fuel tank, a fuel pressure sensor that detects the pressure of the pressurized fuel, and a high-pressure pump that pressurizes fuel transferred from a fuel tank. and an injection valve that injects and supplies fuel to the internal combustion engine (paragraph 0011, claim 1, summary, FIG. 1). This conventional high-pressure fuel supply system for an internal combustion engine feeds back the pressurized fuel pressure so that the detected fuel pressure becomes a target pressure, and supplies the internal combustion engine with the fuel pressure through the injection valve according to its operating state. Supply a fixed amount of high pressure fuel.

This conventional high-pressure fuel supply system for an internal combustion engine is characterized by comprising a detection means, a holding means, and a control means. The detection means detects an abnormality in the fuel pressure sensor. The holding means forcibly holds the fuel pressure at a predetermined pressure based on detection of an abnormality in the fuel pressure sensor. The control means estimates the fuel pressure and injects an amount of fuel to the internal combustion engine based on the estimated fuel pressure until the fuel pressure reaches the predetermined pressure after the abnormality of the fuel pressure sensor is detected. control.

The fuel injection control device described in Patent Document 2 below includes an injector that injects fuel into an internal combustion engine, a fuel pressure sensor that detects the fuel pressure supplied to the injector, and an injector that detects the operating state of the internal combustion engine. It is provided with various sensors and a fuel supply control section that calculates the fuel supply amount based on the signals from these fuel pressure sensors and the various sensors and drives and controls the injector (Paragraph 0009, Claim 1, Summary, FIG. 2). The fuel supply control section includes an injector valve opening signal generation means, a first drive current supply signal generation means, a first drive current supply means, a second drive current supply means, and a fuel pressure sensor failure detection means. .

The injector valve opening signal generating means calculates the fuel supply amount based on the signals from the various sensors, and outputs the injector valve opening signal based on the fuel supply amount. The first drive current supply signal generating means sets a first drive current supply time for supplying the first drive current at the injector opening timing based on the signal from the fuel pressure sensor, and outputs a first drive current supply signal. do. The first drive current supply means provides a first drive to the injector based on an injector valve opening signal from the injector valve opening signal generation means and a first drive current supply signal from the first drive current supply signal generation means. Supply current.

After supplying the first drive current, the second drive current supply means supplies a second drive current lower than the first drive current to the injector based on an injector valve opening signal from the injector valve opening signal generation means. . The fuel pressure sensor failure detection means detects failure of the fuel pressure sensor based on a signal from the fuel pressure sensor. The first drive current supply signal generating means sets the first drive current supply time to a predetermined fixed time when the fuel pressure sensor failure detection means detects a failure of the fuel pressure sensor.

The fuel supply control device for an internal combustion engine described in Patent Document 3 below detects the fuel pressure in a fuel supply pipe that supplies fuel from a fuel pump to a fuel injection valve, and controls the fuel pressure so that the detected fuel pressure approaches a target fuel pressure. to control the above fuel pump. This conventional fuel supply control device for an internal combustion engine includes a response characteristic calculation means, a manipulated variable calculation means, a control means, a diagnosis means, and a setting means (Paragraphs 0020 to 0028, Claim 1 ).

The response characteristic calculating means calculates an operational response characteristic of the fuel pump for controlling the fuel pressure to the target fuel pressure. The operation amount calculation means calculates the operation amount of the fuel pump according to the operation response characteristic calculated by the response characteristic calculation means. The control means controls the fuel pump based on the operation amount calculated by the operation amount calculation means. The diagnostic means diagnoses a failure of a sensor that detects fuel pressure within the fuel supply pipe.

The setting means sets a fuel pressure corresponding to the operating state of the internal combustion engine to the target fuel pressure when the diagnostic means diagnoses that no failure has occurred in the sensor, and sets the fuel pressure detected by the sensor to the target fuel pressure. Set the fuel pressure to the fuel pressure for fuel injection control. On the other hand, when the diagnosis means diagnoses that a failure has occurred in the sensor, the setting means sets a predetermined pressure for failure as the target fuel pressure, and sets the operation response characteristic for the fuel injection control. Set the fuel pressure to .

Japanese Patent Application Publication No. 11-210532 Japanese Patent Application Publication No. 2007-138772 Japanese Patent Application Publication No. 2013-064378

The pressure (fuel pressure) of fuel supplied to an injector that injects fuel into an engine is now required to be as high as, for example, about 35 MPa. Therefore, it is necessary to control the injector to drive the injector with a drive current that increases in accordance with the increased fuel pressure. However, if the fuel pressure sensor that detects fuel pressure malfunctions or an abnormality occurs in the detected fuel pressure value, an insufficient injector driving power is calculated based on the abnormal fuel pressure, and as a result, the internal combustion engine due to the injector valve opening failure There is a risk that the engine may stop or the rotation speed may decrease.

The present disclosure makes it possible to prevent an injector from opening incorrectly when a fuel pressure sensor that detects the pressure of fuel supplied to an injector malfunctions or a detected value abnormality occurs, thereby preventing an engine from stopping or a decrease in rotational speed. Provides electronic control equipment.

One aspect of the present disclosure is an electronic control device that controls an engine system including an injector that injects fuel into a combustion chamber of an engine, and a fuel pressure sensor that detects the fuel pressure of the fuel supplied to the injector, a target fuel pressure calculation unit that calculates a target fuel pressure of the fuel to be supplied to the injector; a fuel pressure acquisition unit that acquires a fuel pressure detection value of the fuel pressure sensor; a failure detection unit that detects a failure of the sensor; a failure determination unit that determines a failure of the fuel pressure sensor when detection of the fuel pressure sensor failure continues beyond a first period; and the target fuel pressure and the detected fuel pressure value. an abnormality detection unit that detects an abnormality in the detected fuel pressure value based on a difference between the detected fuel pressure value and the amount of change per unit time in the detected fuel pressure value, and an abnormality in the detected fuel pressure value that continues beyond a second period. an abnormality determination unit that determines whether the fuel pressure detection value is abnormal when the fuel pressure detection value is detected; and a drive current setting unit that sets a drive current of the injector, and the drive current setting unit is configured to detect a failure of the fuel pressure sensor or During the period from the detection of the detected value abnormality to the determination of the fuel pressure sensor failure or the determination of the detected value abnormality, the drive current of the injector is set to a value at a time before the fuel pressure sensor failure and the detected value abnormality are detected. The electronic control device is characterized in that it sets a provisional drive current according to the detected fuel pressure value.

According to the above-mentioned aspect of the present disclosure, when a failure or an abnormal detected value occurs in a fuel pressure sensor that detects the fuel pressure of fuel supplied to an injector, an injector valve opening failure is prevented, and the engine is stopped or the rotational speed is decreased. It is possible to provide an electronic control device that can prevent this.

1 is a schematic configuration diagram of an engine system showing an embodiment of an electronic control device of the present disclosure. 2 is a schematic configuration diagram of a fuel supply system of the engine system in FIG. 1. FIG. 2 is a block diagram showing a schematic configuration of the electronic control device in FIG. 1. FIG. 2 is a functional block diagram of the electronic control device in FIG. 1. FIG. 5 is a flow diagram illustrating a control process of the engine system by the electronic control device of FIG. 4. FIG. 5 is a timing chart when the electronic control device of FIG. 4 controls the engine system. FIG. 6 is a flowchart showing details of the process (P08) when a failure is detected in FIG. 5; 6 is a flowchart showing details of the failure determination process (P09) of FIG. 5. FIG. FIG. 6 is a flowchart showing details of the process (P10) when a failure is confirmed in FIG. 5; FIG. 8 is a flowchart showing a first modification of the processing upon detecting a failure, etc. (P08) in FIG. 7; FIG. 8 is a flowchart showing a second modification of the process (P08) at the time of detection of a failure, etc. in FIG. 7; FIG. 5 is a functional block diagram showing modification example 1 of the electronic control device shown in FIG. 4; 13 is a flow diagram illustrating the operation of the electronic control device of Modification 1 shown in FIG. 12. FIG. 13 is a timing chart illustrating the operation of the electronic control device of Modification 1 shown in FIG. 12. FIG. 5 is a functional block diagram showing a second modification of the electronic control device shown in FIG. 4. FIG. FIG. 16 is a flowchart illustrating the operation of the electronic control device of modification 2 shown in FIG. 15; 16 is a timing chart illustrating the operation of the electronic control device of modification 2 shown in FIG. 15. FIG. 5 is a functional block diagram showing a third modification of the electronic control device shown in FIG. 4. FIG. FIG. 19 is a flowchart illustrating the operation of the electronic control device of modification 3 shown in FIG. 18; 19 is a timing chart illustrating the operation of the electronic control device of modification 3 shown in FIG. 18. FIG.

FIG. 1 is a schematic configuration diagram of an engine system ES showing an embodiment of the electronic control device of the present disclosure. The engine system ES is mounted on a vehicle, for example, and generates power for driving the vehicle. The engine system ES includes, for example, an intake system 1, a fuel supply system 2, an engine 3, an exhaust system 4, an electronic control device 5, and an accelerator opening sensor 6. In the following description, the electronic control unit 5 will be abbreviated as "ECU5" as appropriate.

The intake system 1 includes, for example, an intake sensor 11, a throttle valve 12, a collector 13, and an intake manifold 14. The intake air sensor 11 detects physical quantities such as the flow rate, temperature, humidity, and pressure of air taken into the intake system 1. The intake sensor 11 is connected to the ECU 5 via wiring, and outputs the detected physical quantity to the ECU 5.

The throttle valve 12 includes a valve body, an opening sensor that detects the opening degree of the valve body, and a motor that drives the valve body. The throttle valve 12 is connected to the ECU 5 via wiring, and its opening degree is controlled by the ECU 5. The collector 13 distributes the air flowing in through the throttle valve 12 to each branch of the intake manifold 14. The intake manifold 14 supplies the air distributed by the collector 13 to the combustion chamber 31 of the engine 3. For example, an intake pipe pressure sensor (not shown) is installed in the intake manifold 14 and outputs a detection result of intake air pressure to the ECU 5.

FIG. 2 is a schematic configuration diagram of the fuel supply system 2 of the engine system ES of FIG. 1. The fuel supply system 2 includes, for example, a fuel tank 21, a low pressure fuel pump 22, a regulator 23, a low pressure fuel supply pipe 24 (low pressure fuel supply passage), a high pressure fuel pump 25, a high pressure fuel supply pipe 26, and a common rail. 27, a fuel pressure sensor 28, and an injector 29. The fuel tank 21 stores fuel such as gasoline, for example. The low pressure fuel pump 22 supplies low pressure fuel to the high pressure fuel pump 25 or the common rail 27 via the low pressure fuel supply pipe 24, for example.

The regulator 23 keeps the fuel in the low-pressure fuel supply pipe 24 constant by returning the fuel in the low-pressure fuel supply pipe 24 to the fuel tank 21 when the pressure of the fuel in the low-pressure fuel supply pipe 24 exceeds a predetermined pressure. Adjust the pressure to . The high-pressure fuel pump 25 is driven, for example, by power transmitted from the camshaft of an exhaust cam that drives the exhaust valve 34 of the engine 3. The high-pressure fuel pump 25 increases the pressure of the fuel supplied from the low-pressure fuel pump 22 and supplies high-pressure fuel to the common rail 27 via the high-pressure fuel supply pipe 26 .

The common rail 27 supplies high-pressure fuel supplied from the high-pressure fuel pump 25 via the high-pressure fuel supply pipe 26 to the plurality of injectors 29. The fuel pressure sensor 28 detects, for example, the pressure of fuel supplied to the common rail 27 (fuel pressure). The fuel pressure sensor 28 is connected to the ECU 5 via wiring, for example, and outputs a detection result of fuel pressure to the ECU 5. Injector 29 is provided in each cylinder of engine 3, for example, and is connected to ECU 5 via wiring. The injector 29 is controlled by the ECU 5 and injects the fuel supplied from the common rail 27 into the combustion chamber 31 of each cylinder of the engine 3.

The engine 3 is, for example, a four-cylinder engine having four cylinders. The engine 3 is not limited to an in-cylinder injection type, and may be, for example, a port injection type or a dual injection spark ignition internal combustion engine that uses both in-cylinder injection and port injection. The engine 3 includes, for example, a combustion chamber 31, a piston 32, an intake valve 33, an exhaust valve 34, an ignition coil 35, a spark plug 36, a crank angle sensor 37, and a water temperature sensor 38. .

The combustion chamber 31 is a space in which a mixture of fuel injected by the injector 29 and air supplied from the intake manifold 14 via the intake valve 33 is combusted. The piston 32 is pushed down by the combustion of the air-fuel mixture in the combustion chamber 31 and rotates the crankshaft. The actuators of the intake valve 33 and the exhaust valve 34 are connected to the ECU 5 via wiring, for example. The actuators for the intake valve 33 and the exhaust valve 34 open and close the intake valve 33 and the exhaust valve 34, respectively, under the control of the ECU 5, for example.

The ignition coil 35 is connected to the ECU 5 via wiring, for example. The ignition coil 35 generates high voltage under the control of the ECU 5. The spark plug 36 ignites the air-fuel mixture in the combustion chamber 31 by being discharged by the high voltage generated by the ignition coil 35. The crank angle sensor 37 detects the angle of the crankshaft of the engine 3. The crank angle sensor 37 is connected to the ECU 5 via wiring, for example, and outputs an angle detection result to the ECU 5. Water temperature sensor 38 detects the temperature of the cooling water of engine 3. The water temperature sensor 38 is connected to the ECU 5 via wiring, for example, and outputs a temperature detection result to the ECU 5.

The exhaust system 4 includes, for example, an exhaust manifold 41, an oxygen sensor 42, and a three-way catalyst 43. The exhaust manifold 41 collects exhaust gas discharged from the combustion chamber 31 of each cylinder via the exhaust valve 34. The oxygen sensor 42 detects the oxygen concentration of the exhaust gas that has passed through the exhaust manifold 41. The oxygen sensor 42 is connected to the ECU 5 via wiring, for example, and outputs the detected oxygen concentration to the ECU 5. The three-way catalyst 43 purifies harmful components in exhaust gas by oxidation and reduction.

The ECU 5 is, for example, an engine control unit that controls overall control of the engine system ES, including fuel injection by the injector 29. For example, the ECU 5 calculates the amount of fuel injected by the injector 29 based on engine state quantities including the crank rotation angle, throttle opening, engine speed, fuel pressure, etc. obtained from various sensors of the engine system ES, and calculates the amount of fuel injected by the injector 29. Controls the fuel pump 25, injector 29, etc.

FIG. 3 is a block diagram showing a schematic configuration of the ECU 5 in FIG. 1. The ECU 5 is configured by a computer including, for example, an input circuit 51, an A/D conversion section 52, a central processing unit (CPU) 53, a ROM 54, a RAM 55, and an output circuit 56. Note that the ECU 5 may be configured with an FPGA (Field Programmable Gate Array), which is a rewritable logic circuit, an ASIC (Application Specific Integrated Circuit), which is a rewritable logic circuit, or a combination of ROM, RAM, and FPGA. It is possible.

The input circuit 51 receives outputs from various sensors such as the intake sensor 11, the throttle valve 12 opening sensor, the fuel pressure sensor 28, the crank angle sensor 37, the water temperature sensor 38, the oxygen sensor 42, and the accelerator opening sensor 6. Signals SS1, SS2, SS3, . . . are input. For example, when the input signal is an analog signal, the input circuit 51 removes noise from the analog signal and outputs the noise-removed analog signal to the A/D converter 52. Further, for example, when the input signal is a digital signal, the input circuit 51 outputs the digital signal as it is to the CPU 53. The A/D converter 52 converts the analog signal input from the input circuit 51 into a digital signal and outputs the digital signal to the CPU 53.

For example, by executing control logic such as a program stored in the ROM 54, the CPU 53 performs various calculations using the detection results of each sensor input as a digital signal from the input circuit 51 or the A/D converter 52. Perform diagnosis and control. For example, the CPU 53 causes the RAM 55 to temporarily hold detection results, calculation results, diagnosis results, etc. of each sensor. For example, the CPU 53 outputs control signals CS1, CS2, CS3, ... including the drive current of the injector 29 to each part of the engine system ES including the injector 29 via the output circuit 56 based on the calculation result and the diagnosis result. do.

FIG. 4 is a functional block diagram showing details of the function of outputting the drive current I of the injector 29 in the ECU 5 of FIG. 1. The ECU 5 includes, for example, a target fuel pressure calculation section 501, a fuel pressure acquisition section 502, a failure detection section 503, a failure determination section 504, an abnormality detection section 505, an abnormality determination section 506, and a drive current setting section 507. have. Further, in the example shown in FIG. 4, the ECU 5 includes, for example, a fail-safe processing section 508, a high-pressure fuel pump control section 509, a drive current calculation section 510, and a drive current output section 511. Note that each part of the ECU 5 shown in FIG. 4 represents each function of the ECU 5 that is realized by, for example, executing a program stored in the ROM 54 by the CPU 53 shown in FIG. 3.

FIG. 5 is a flow diagram illustrating the control process P of the engine system ES by the ECU 5 of FIG. 4. FIG. 6 is a timing chart when the ECU 5 shown in FIG. 4 controls the engine system ES.

More specifically, the horizontal axis of each chart in FIG. 6 is time, and the vertical axis of the top chart is the presence (Y)/absence of detection of a failure of the fuel pressure sensor 28 (fuel pressure sensor failure) or an abnormality in the detected value. (N). The vertical axis of the second chart from the top of FIG. 6 is the fuel pressure of the fuel supplied to the injector 29, the solid line indicates the actual fuel pressure FPr, and the dashed line indicates the fuel pressure detected value FPs by the fuel pressure sensor 28.

The vertical axis of the second chart from the bottom in FIG. 6 is the drive current input to the injector 29, the solid line shows the drive current by the ECU 5 of this embodiment, and the broken line shows the drive current by the conventional device. ing. The vertical axis of the bottom chart in FIG. 6 is the rotation speed of the engine 3, the solid line indicates the rotation speed of the engine 3 under control of the ECU 5 of this embodiment, and the broken line indicates the rotation speed of the engine under control of the conventional device. It shows the number.

Hereinafter, while explaining each process of the control process shown in FIG. 5, the operation of each part of the ECU 5 shown in FIG. 4 will be explained. When the ECU 5 starts the control process P shown in FIG. 5, it executes, for example, a process P01 for calculating the target fuel pressure FPt. In this process P01, the target fuel pressure calculation unit 501 calculates, for example, the intake air amount Qa input from the intake sensor 11 to the ECU 5, the rotation speed Ne of the engine 3 based on the rotation angle input from the crank angle sensor 37 to the ECU 5, etc. Based on this, the target fuel pressure FPt of the fuel supplied to the injector 29 is calculated.

Next, the ECU 5 executes, for example, a process P02 to obtain fuel pressure. In this process P02, the fuel pressure acquisition unit 502 acquires, for example, the fuel pressure detection value FPs input from the fuel pressure sensor 28 to the ECU 5. Next, the ECU 5 executes, for example, a process P03 for controlling the high-pressure fuel pump 25.

In this process P03, the high-pressure fuel pump control unit 509 controls whether the high-pressure fuel pump 25 supplies fuel based on the signal SS input from the accelerator opening sensor 6, the throttle valve 12 opening sensor, the crank angle sensor 37, etc., for example. Controls the discharge amount. Thereby, the pressure of the fuel supplied to the injector 29, that is, the fuel pressure, is controlled to a desired pressure. Here, the high-pressure fuel pump control unit 509 may perform feedback control on the discharge amount of the high-pressure fuel pump 25, for example, so that the fuel pressure detection value FPs of the fuel pressure sensor 28 and the target fuel pressure FPt match.

Next, the ECU 5 executes, for example, a process P04 for calculating the drive current of the injector 29. In this process P04, the drive current calculation unit 510 calculates the drive current of the injector 29 based on the fuel pressure detection value FPs of the fuel pressure sensor 28 acquired by the fuel pressure acquisition unit 502, for example. Further, the drive current calculation unit 510 calculates the drive current of the injector 29 based on, for example, the target fuel pressure FPt calculated by the target fuel pressure calculation unit 501 and the detected fuel pressure value FPs. More specifically, the drive current calculation unit 510 calculates the drive current of the injector 29 based on, for example, the difference between the target fuel pressure FPt and the detected fuel pressure value FPs.

Next, the ECU 5 executes, for example, a process P05 that determines whether or not a fuel pressure sensor failure or detected value abnormality is detected. In this process P05, the failure detection unit 503 detects a fuel pressure sensor failure, which is a failure of the fuel pressure sensor 28, based on the fuel pressure detection value FPs of the fuel pressure sensor 28 acquired by the fuel pressure acquisition unit 502. Here, the fuel pressure sensor failure detected by the failure detection unit 503 includes, for example, a ground fault or disconnection of the fuel pressure sensor 28.

In addition, in this process P05, the abnormality detection unit 505 detects the fuel pressure based on the fuel pressure detection value FPs of the fuel pressure sensor 28 acquired by the fuel pressure acquisition unit 502 and the target fuel pressure FPt calculated by the target fuel pressure calculation unit 501. An abnormality in the value FPs is detected. Here, an abnormality in the fuel pressure detection value FPs of the fuel pressure sensor 28 detected by the abnormality detection unit 505, that is, a detection value abnormality is, for example, the difference between the target fuel pressure FPt and the fuel pressure detection value FPs and the difference in the fuel pressure detection value FPs per unit time. This is a state in which the amount of change exceeds a preset threshold value. Such a detected value abnormality may be caused by, for example, a microcontroller abnormality or an input abnormality.

For example, as shown in FIG. 6, if a failure or an abnormality in the detected fuel pressure value FPs does not occur in the fuel pressure sensor 28 until time t1, the failure detection unit 503 determines whether the fuel pressure sensor has failed or detected the detected value in process P05 before time t1. It is determined that no abnormality has been detected (NO).

In this case, the ECU 5 executes a process P06 for setting the drive current of the injector 29. In this process P06, the drive current setting section 507 sets the drive current of the injector 29 based on the detected fuel pressure value FPs. More specifically, the drive current setting unit 507 sets the drive current based on the fuel pressure detection value FPs calculated by the drive current calculation unit 510 until, for example, a fuel pressure sensor failure or a detection value abnormality is detected in process P05. Next, it is set as the drive current to be output to the injector 29.

Next, the ECU 5 executes, for example, a process P07 of outputting a drive current. In this process P07, the drive current output section 511 outputs, for example, the drive current set by the drive current setting section 507 to the injector 29. As a result, the injector 29 opens in response to the drive current input from the ECU 5. As a result, as shown in FIGS. 1 and 2, high-pressure fuel is supplied from the fuel tank 21 to the high-pressure fuel pump 25 by the low-pressure fuel pump 22, and is further pressurized by the high-pressure fuel pump 25 and discharged to the common rail 27. , is injected from the injector 29 into the combustion chamber 31 of the engine 3.

The injector 29 is, for example, an in-cylinder direct injection type injector that injects fuel multiple times during one cycle of the engine 3. The injector 29 injects fuel into the combustion chamber 31 by opening for a period specified by a drive current input from the ECU 5. The total fuel injection amount, which is the total amount of fuel injected by the injector 29 during one cycle, can be set in advance, and the injection amount for each fuel injection performed multiple times can also be set in advance. .

Thereafter, the ECU 5 repeatedly executes the above-described processes P01 to P07 at a predetermined cycle until, for example, time t1 shown in FIG. 6. After that, at time t1, a failure of the fuel pressure sensor 28 or an abnormality in the detected fuel pressure value FPs occurs, and as shown in the second chart from the top of FIG. Suppose that the value decreases to . Then, the difference between this detected fuel pressure value FPs and the actual fuel pressure FPr of the fuel supplied to the injector 29, indicated by a solid line, increases.

In this case, for example, in process P05 shown in FIG. 5 immediately after time t1, the failure detection unit 503 determines that a fuel pressure sensor failure has been detected (YES), or the failure detection unit 505 detects a detected value abnormality. Determine whether you have done so (YES). In this case, the ECU 5 executes, for example, a failure detection process P08, a failure confirmation process P09, and a failure confirmation process P10, as shown in FIG. 5, for example.

FIG. 7 is a flow diagram showing details of the failure etc. detection process P08 in FIG. 5. When the ECU 5 starts this process P08, it first executes a process P081 in which it is determined whether or not a definite determination of fuel pressure sensor failure is being executed. In this process P081, the failure determination unit 504 executes a determination of the fuel pressure sensor failure, for example, when the failure detection unit 503 has not detected a fuel pressure sensor failure, or when the fuel pressure sensor failure has already been determined. Determine if it has not been done (NO).

In this case, the ECU 5 executes, for example, a process P082 that determines whether or not the determination of the detection value abnormality is being executed. In this process P082, the abnormality determining unit 506 executes the determination of the detected value abnormality, for example, when the detected value abnormality is not detected by the abnormality detecting unit 505, or when the detected value abnormality has already been determined. Determine if it has not been done (NO). In this case, the ECU 5 ends the process P08 shown in FIG. 7 and executes the next failure determination process P09.

On the other hand, in process P081, the failure determining unit 504 determines that, as shown in the top chart of FIG. 6, the failure detecting unit 503 continues to detect a fuel pressure sensor failure (Y), and If the state does not exceed the first period TP1, it is determined that the determination of fuel pressure sensor failure is being executed (YES). Similarly, in process P082, the abnormality determining unit 506 determines that when the abnormality detecting unit 505 continues to detect a detected value abnormality (Y) and this state does not exceed the second period TP2, It is determined that the determination of the detection value abnormality is being executed (YES).

In these cases, the ECU 5 executes the following process P083. Note that the first period TP1 for determining fuel pressure sensor failure and the second period TP2 for determining detected value abnormality can be set to any period necessary to determine each event. Therefore, the first period TP1 and the second period TP2 may be the same or different. In FIG. 6, for convenience of explanation, the first period TP1 and the second period TP2 are shown as the same period from time t1 to time t2.

In process P083, the ECU 5 sets a provisional drive current based on the fuel pressure detection value FPs at a time before the failure or abnormality detection. In this process P083, the drive current setting unit 507 determines, for example, as the drive current to be output next to the injector 29, a drive current based on the fuel pressure detection value FPs of the fuel pressure sensor 28 after the fuel pressure sensor failure or detection value abnormality is detected. Set a different interim drive current.

More specifically, in this process P083, the drive current setting unit 507 sets the drive current to be outputted to the injector 29 next at a time point before time t1 at which the fuel pressure sensor failure or detected value abnormality is detected. A provisional drive current is set based on the detected fuel pressure value FPs. For example, the drive current setting unit 507 sets the drive current set in the process immediately before time t1 at which the fuel pressure sensor failure or detected value abnormality is detected as the provisional drive current.

As a result, as shown by the solid line in the second chart from the bottom of FIG. 6, the ECU 5 Therefore, the drive current output from the injector 29 to the injector 29 does not change significantly. As a result, when the fuel pressure sensor 28 fails or an abnormal detected value occurs, it is possible to prevent the injector from opening incorrectly. Therefore, even after time t1 when the fuel pressure detection value FPs of the fuel pressure sensor 28 deviates from the actual fuel pressure FPr, as shown by the solid line in the bottom chart of FIG. It can be prevented.

On the other hand, as shown by the broken line in the second chart from the bottom of FIG. It decreases rapidly as the value decreases. As a result, in the conventional device, the drive current that corresponds to the fuel pressure detection value of the fuel pressure sensor and the drive current that corresponds to the actual fuel pressure of the fuel supplied to the injector diverge. Therefore, with conventional devices, injector valve opening failure occurs due to insufficient drive current, and in that case, as shown by the broken line in the bottom chart of Figure 6, there is a risk that the engine will stop or the rotation speed will drop. There is.

After that, the ECU 5 ends the process P08 shown in FIG. 7 and executes the next failure determination process P09. FIG. 8 is a flowchart showing details of the failure determination process P09 of FIG. 5. When the ECU 5 starts this process P09, it first executes a process P091 to determine whether the duration of the fuel pressure sensor failure exceeds the first period TP1. In this process P091, the failure determination unit 504 determines whether, for example, the failure detection unit 503 has not detected a fuel pressure sensor failure, if the fuel pressure sensor failure has already been determined, or if the fuel pressure sensor failure continues to be detected. If the current period does not exceed the first period TP1, a negative determination (NO) is made.

Additionally, the ECU 5 executes a process P092 to determine whether the duration of the detected value abnormality exceeds the second period TP2. In this process P092, the abnormality determination unit 506 determines whether, for example, the abnormality detection unit 505 has not detected a detected value abnormality, if the detected value abnormality has already been determined, or if the detection value abnormality continues to be detected. If the current period does not exceed the second period TP2, a negative determination (NO) is made. In this case, the ECU 5 ends the process P09 shown in FIG. 8 and executes the next process P10 when a failure is determined.

On the other hand, in process P091, the failure determination unit 504 determines that, as shown in the top chart of FIG. 6, the failure detection unit 503 continues to detect a fuel pressure sensor failure (Y), and If the state exceeds the first period TP1, an affirmative (YES) determination is made. In this case, the failure determining unit 504 executes a process P093 to determine the fuel pressure sensor failure, and ends the process P09 shown in FIG. 8.

Similarly, in process P092, the abnormality determination unit 506 determines if the abnormality detection unit 505 continues to detect a detected value abnormality (Y) and if this state exceeds the second period TP2, (YES) is determined. In this case, the abnormality determining unit 506 executes a process P094 for determining the detected value abnormality, and ends the process P09 shown in FIG. 8. After that, the ECU 5 executes the next failure confirmation process P10.

FIG. 9 is a flowchart showing details of the process P10 when a failure is determined in FIG. 5. When the ECU 5 starts this process, it first executes process P101 to determine whether a fuel pressure sensor failure or detected value abnormality has been determined. In this process P101, the failsafe processing unit 508 makes a negative determination (NO), for example, when the failure determination unit 504 has not determined that a fuel pressure sensor failure or detected value abnormality has occurred.

In this case, in the next process P103, the failsafe processing unit 508 maintains the drive current to be output to the injector 29 next time at the drive current output to the injector 29 last time, and outputs it to the drive current setting unit 507. After that, the ECU 5 ends the process P10 shown in FIG. 9 and executes the process P06 and the process P07 shown in FIG. 5. As a result, the drive current setting section 507 sets a provisional drive current as the drive current to be output to the injector 29 from the detection of the fuel pressure sensor failure or the detected value abnormality to the determination, and thereby the drive current output section 511 outputs the injector 29 to the injector 29. A provisional drive current is output to.

On the other hand, in process P101, the failsafe processing unit 508 makes an affirmative determination (YES), for example, when the failure determination unit 504 determines a fuel pressure sensor failure or a detected value abnormality. In this case, in the next process P102, the failsafe processing unit 508 determines whether the drive current to be output to the injector 29 next is larger than the set value at the time when the fuel pressure sensor failure is determined. In this process P102, when the fail-safe processing unit 508 determines that the drive current is larger than the set value at the time when the fuel pressure sensor failure is confirmed (YES), the fail-safe processing unit 508 performs a process of gradually decreasing the drive current and outputting it to the drive current setting unit 507. Execute P104.

After that, the ECU 5 ends the process P10 shown in FIG. 9 and executes the process P06 and the process P07 shown in FIG. 5.

More specifically, the high-pressure fuel pump control unit 509 shown in FIG. Based on the detected fuel pressure value FPs, feedback control is performed to set the amount of fuel discharged to the injector 29 by the high-pressure fuel pump 25 shown in FIGS. 1 and 2. In addition, the high-pressure fuel pump control unit 509 temporarily stops the feedback control of the fuel discharge amount during the period from the detection of fuel pressure sensor failure or detected value abnormality to the determination of fuel pressure sensor failure or detected value abnormality. In this case, for example, feedforward control of the fuel discharge amount can be performed based on the target fuel pressure FPt at a point in time before the fuel pressure sensor failure or detected value abnormality is detected. In addition, the high-pressure fuel pump control unit 509 controls the low-pressure fuel supply pipe 24 by the low-pressure fuel pump 22 by stopping the pressurized discharge of fuel by the high-pressure fuel pump 25 when a fuel pressure sensor failure or detected value abnormality is confirmed. Fuel is supplied to the injector 29 via the injector 29. When a fuel pressure sensor failure or detected value abnormality is confirmed, the drive current setting unit 507 sets the drive current to be output to the injector 29 next from the provisional drive current to be supplied to the injector 29 by the low-pressure fuel pump 22. The drive current corresponding to the fuel pressure is gradually reduced to the set value at the time of sensor failure, etc.

On the other hand, in process P102, if the failsafe processing unit 508 determines that the drive current is less than or equal to the set value when the fuel pressure sensor failure is confirmed (NO), it executes process P103 to maintain the drive current. This prevents the drive current output from the ECU 5 to the injector 29 from becoming smaller than necessary, and prevents the injector 29 from opening incorrectly.

Hereinafter, the operation of the ECU 5 of this embodiment will be explained based on comparison with a conventional device.

As described above, the ECU 5 of this embodiment is an engine system ES that includes an injector 29 that injects fuel into the combustion chamber 31 of the engine 3, and a fuel pressure sensor 28 that detects the fuel pressure of the fuel supplied to the injector 29. This is an electronic control device that controls the As shown in FIG. 5, the ECU 5 includes a target fuel pressure calculation section 501, a fuel pressure acquisition section 502, a failure detection section 503, a failure determination section 504, an abnormality detection section 505, an abnormality determination section 506, and a drive current setting section. 507. The target fuel pressure calculation unit 501 calculates a target fuel pressure FPt of fuel supplied to the injector 29. The fuel pressure acquisition unit 502 acquires the fuel pressure detection value FPs of the fuel pressure sensor 28. The failure detection unit 503 detects a fuel pressure sensor failure, which is a failure of the fuel pressure sensor 28, based on the detected fuel pressure value FPs. The failure determining unit 504 determines the fuel pressure sensor failure when detection of the fuel pressure sensor failure continues beyond the first period TP1. The abnormality detection unit 505 detects a detected value abnormality in which the difference between the target fuel pressure FPt and the detected fuel pressure value FPs and the amount of change per unit time in the detected fuel pressure value FPs each exceed a threshold value. The abnormality determining unit 506 determines the detected value abnormality when the detection of the detected value abnormality continues beyond the second period TP2. The drive current setting unit 507 sets the drive current of the injector 29 based on the fuel pressure detection value FPs until a fuel pressure sensor failure or an abnormality in the detection value is detected. Then, the drive current setting unit 507 sets a provisional drive current based on the fuel pressure detection value FPs before the fuel pressure sensor failure or detection value abnormality is detected as the drive current from the detection of the fuel pressure sensor failure or detection value abnormality to its determination. Set.

With such a configuration, as shown in the time chart of FIG. 6, even if a fuel pressure sensor failure or detected value abnormality occurs and the fuel pressure detected value FPs by the fuel pressure sensor 28 deviates from the actual fuel pressure FPr, the next injector This prevents the drive current output to 29 from decreasing. Therefore, according to the ECU 5 of this embodiment, when the fuel pressure sensor 28 that detects the fuel pressure of the fuel supplied to the injector 29 has a failure or an abnormal detected value occurs, the valve opening failure of the injector 29 is prevented and the engine 3 is It is possible to prevent stoppage and decrease in rotational speed.

Furthermore, in the electronic control device 5 of this embodiment, the drive current setting unit 507 gradually reduces the drive current from the provisional drive current when a fuel pressure sensor failure or detected value abnormality is determined.

With such a configuration, as shown by the solid line in the second chart from the bottom of FIG. It can be gradually reduced to a predetermined set value when a failure or detected value abnormality is determined. Therefore, according to the ECU 5 of this embodiment, compared to the case where the injector drive current is set to a relatively large value such as the maximum drive current after the fuel pressure sensor failure is determined as in the conventional device shown by the broken line in FIG. As a result, it is possible to reduce the impact when opening and closing the injector 29 and improve the durability of the injector 29.

The engine system ES controlled by the electronic control device 5 of this embodiment also includes a high-pressure fuel pump 25 that supplies fuel to the injector 29 and a low-pressure fuel pump 22 that supplies fuel from the fuel tank 21 to the high-pressure fuel pump 25. including. The ECU 5 includes a high-pressure fuel pump control section 509 that controls the amount of fuel discharged by the high-pressure fuel pump 25 based on the target fuel pressure FPt. The high-pressure fuel pump control unit 509 stops the pressurized discharge of fuel by the high-pressure fuel pump 25 when a fuel pressure sensor failure or detected value abnormality is determined, thereby causing the low-pressure fuel pump 22 to supply fuel via the low-pressure fuel supply pipe 24. to supply the fuel to the injector 29. Further, when a fuel pressure sensor failure or abnormality in detected value is confirmed, the drive current setting unit 507 changes the drive current of the injector 29 from the provisional drive current to the fuel pressure of the fuel supplied to the injector 29 by the low-pressure fuel pump 22. Gradually decrease the drive current to the corresponding value.

With this configuration, as shown by the solid line in the second chart from the bottom of FIG. It can be gradually decreased depending on the pressure of the fuel supplied to the injector 29. Therefore, according to the ECU 5 of this embodiment, compared to the case where the injector drive current is set to a relatively large value such as the maximum drive current after the fuel pressure sensor failure is determined as in the conventional device shown by the broken line in FIG. As a result, it is possible to more reliably reduce the impact when the injector 29 is opened and closed, and to improve the durability of the injector 29 more reliably.

As described above, according to the present embodiment, when an abnormality occurs in the injector 29 that detects the pressure of fuel supplied to the injector 29, a valve opening failure of the injector 29 is prevented, and the engine 3 is stopped or the rotation speed is reduced. It is possible to provide an electronic control device 5 that can prevent deterioration and improve the durability of the injector 29.

On the other hand, in the conventional device, as shown by the broken line in the time chart of FIG. 6, when it is determined that the fuel pressure sensor is abnormal, the injector drive current is set to the maximum drive current regardless of the time. Therefore, in the conventional device, the durability of the injector decreases due to the increased impact when the injector is opened and closed. Further, in the conventional device, the operation of the injector cannot correspond to the actual fuel pressure before the failure of the fuel pressure sensor is determined.

Note that the electronic control device according to the present disclosure is not limited to the ECU 5 according to the above-described embodiment. Hereinafter, some modified examples of the above-mentioned ECU 5 will be described with reference to FIGS. 10 to 20.

FIG. 10 is a flowchart showing a first modification of the process P08 at the time of detection of failure etc. in FIG. 7. In this modification, the ECU 5 executes processing P084, processing P085, and processing P086 instead of processing P083 shown in FIG. In process P084, the ECU 5 determines whether the fuel pressure detection value FPs of the fuel pressure sensor 28 is larger than the fuel pressure detection value FPs before the detection of the fuel pressure sensor failure or detection value abnormality, while executing the definitive determination of the fuel pressure sensor failure or detection value abnormality. Determine whether or not.

In this process P084, the drive current setting unit 507 sets, for example, the most recent fuel pressure detection value FPs after the fuel pressure sensor failure or detected value abnormality is detected, and the time t1 when the fuel pressure sensor failure or detected value abnormality is detected. The fuel pressure detection value FPs is compared with the past fuel pressure detection value FPs at the time of the third period. Here, the third period is, for example, equal to the execution cycle of the process flow shown in FIG. 5 by the ECU 5, or a period that is an integral multiple of the execution cycle of the process flow shown in FIG.

In this process P084, the drive current setting unit 507 determines that the past fuel pressure detection value FPs before the fuel pressure sensor failure etc. was detected is greater than or equal to the most recent fuel pressure detection value FPs after the fuel pressure sensor failure etc. was detected. If it is determined that it is true (NO), the next process P085 is executed. In this process P085, the drive current setting unit 507 provisionally outputs the drive current calculated by the drive current calculation unit 510 based on the past fuel pressure detection value FPs before the fuel pressure sensor failure etc. is detected to the injector 29. The drive current is set, and the process P08 shown in FIG. 10 is ended.

On the other hand, in process P084, the drive current setting unit 507 determines that the most recent fuel pressure detection value FPs after the fuel pressure sensor failure etc. was detected is higher than the past fuel pressure detection value FPs before the fuel pressure sensor failure etc. was detected. If it is determined that the value is also large (YES), the next process P086 is executed. In this process P086, the drive current setting unit 507 provisionally outputs the drive current calculated by the drive current calculation unit 510 based on the most recent fuel pressure detection value FPs after the fuel pressure sensor failure etc. is detected to the injector 29. The drive current is set, and the process P08 shown in FIG. 10 is ended.

As described above, in the electronic control device 5 according to the modified example shown in FIG. The drive current calculated based on the higher fuel pressure detection value among the fuel pressure detection values FPs at a point in time that is earlier than the previous fuel pressure detection value is set as the provisional drive current. With such a configuration, the ECU 5 of this modification can not only achieve the same effect as the ECU 5 of the above-described embodiment, but also can more reliably prevent valve opening failure of the injector 29, and improve the efficiency of the engine 3. It is possible to more reliably prevent stoppage and decrease in rotational speed.

FIG. 11 is a flowchart showing a second modification of the process P08 at the time of detection of failure, etc. in FIG. In this modification, the ECU 5 executes processing P087a, processing P087b, processing P088, processing P089a, and processing P089b instead of processing P083 shown in FIG. In process P087a, the drive current calculation unit 510 calculates the first drive current of the injector 29 from the fuel pressure detection value FPs of the fuel pressure sensor 28 most recently after the fuel pressure sensor failure or detection value abnormality is detected. In addition, in process P87b, the drive current calculation unit 510 calculates the second drive current of the injector 29 from the fuel pressure detection value FPs of the fuel pressure sensor 28 at a time point that is a third period back from the detection of the fuel pressure sensor failure or detection value abnormality. do.

After that, the drive current setting unit 507 executes a process P088 to determine whether the first drive current calculated by the drive current calculation unit 510 is larger than the second drive current. In this process P088, when the drive current setting unit 507 determines that the first drive current is larger than the second drive current (YES), the drive current setting unit 507 sets the first drive current to a provisional drive current to be output to the injector 29 in a process P089a. is executed, and the process P08 shown in FIG. 11 is ended. On the other hand, in process P088, when the drive current setting unit 507 determines that the second drive current is larger than the first drive current (NO), the drive current setting unit 507 performs a process of setting the second drive current to the provisional drive current to be output to the injector 29. P089b is executed, and the process P08 shown in FIG. 11 is ended.

As described above, in the electronic control device 5 according to the modified example shown in FIG. The larger of the drive current calculated based on FPs and the drive current calculated based on the most recent detected fuel pressure value FPs is set as the provisional drive current. This modified ECU 5 can also provide the same effects as the modified ECU 5 shown in FIG. 10 .

FIG. 12 is a functional block diagram showing a first modification of the ECU 5 shown in FIG. 4. In addition to the parts shown in FIG. 4, the ECU 5 of this modification includes, for example, a fuel injection amount calculation section 512, a fuel injection amount determination section 513, an intake air amount acquisition section 514, and an intake air amount determination section shown in FIG. 515 , an engine rotation speed acquisition section 516 , an engine rotation speed determination section 517 , and a drive current correction section 518 .

FIG. 13 is a flow diagram illustrating the operation of the ECU 5 of Modification 1 shown in FIG. 12. Processes P08A to P08G shown in FIG. 13 are executed, for example, after the provisional drive current is set by the drive current setting unit 507 in process P085 or process P086 of the failure detection process P08 shown in FIG. In process P08A shown in FIG. 13, the fuel injection amount calculation unit 512 determines the total fuel injection amount to be injected from the injector 29 and the number of injections multiple times during one cycle, for example, based on signals input from various sensors of the engine system ES. A target fuel injection amount, which is the injection amount for each fuel injection to be executed, is calculated.

Next, in process P08B, the fuel injection amount determining unit 513 determines whether the amount of change in the total fuel injection amount is within a predetermined range based on the time series data of the total fuel injection amount, and determines whether the amount of change in the total fuel injection amount is outside the predetermined range ( If the determination is NO, the process P08 is ended. On the other hand, in this process P08B, if the fuel injection amount determination section 513 determines that the amount of change in the total fuel injection amount is within the predetermined range (YES), the intake air amount acquisition section 514 acquires the A process P08C is executed to acquire time series data of the intake air amount of the engine 3 based on the input signal.

Next, in process P08D, the intake air amount determining unit 515 determines whether the amount of change in the intake air amount is within a predetermined range, and if it is determined to be outside the predetermined range (NO), ends process P08. On the other hand, in this process P08D, if the intake air amount determination section 515 determines that the intake air amount is within the predetermined range (YES), the engine rotation speed acquisition section 516 calculates, for example, the rotation of the engine 3 based on the signal input from the crank angle sensor 37. A process P08E for acquiring the number is executed.

Next, in process P08F, the engine rotation speed determination unit 517 determines whether the obtained rotation speed of the engine 3 continues to be lower than the threshold value for a predetermined period of time. The engine rotation speed determination unit 517 determines whether the rotation speed of the engine 3 is equal to or higher than a predetermined value, or whether the duration of the state in which the rotation speed of the engine 3 is lower than the predetermined value is equal to or less than a predetermined time (NO). If it is determined, processing P08 is ended.

On the other hand, in this process P08F, when the engine speed determination unit 517 determines that the state in which the rotation speed of the engine 3 is lower than the predetermined value continues for more than a predetermined time (YES), the ECU 5 performs the following process. Processing P08G is executed. In this process P08G, the drive current correction section 518 corrects the provisional drive current to be output to the injector 29 when the fuel pressure sensor failure or the detected value abnormality is confirmed, and the drive current setting section 507 , the provisional drive current corrected by the drive current correction unit 518 is set as a new provisional drive current.

FIG. 14 is a timing chart illustrating the operation of the ECU 5 of Modification 1 shown in FIG. 12. In addition to each item of the timing chart shown in FIG. 6, the timing chart in FIG. 14 includes charts for intake air amount and fuel injection amount.

As described above, the electronic control device 5 of this modification includes a fuel injection amount calculation section 512, an intake air amount acquisition section 514, an engine rotation speed acquisition section 516, and a drive current correction section 518. The fuel injection amount calculation unit 512 calculates the total fuel injection amount of the injector 29. The intake air amount acquisition unit 514 acquires the intake air amount of the engine 3 when the amount of change in the total fuel injection amount is within a predetermined range. The engine rotation speed acquisition unit 516 acquires the rotation speed of the engine 3. The drive current correction unit 518 corrects the provisional drive current to increase when the rotational speed of the engine 3 is lower than a threshold value. The drive current setting unit 507 sets the provisional drive current corrected by the drive current correction unit 518 as a new provisional drive current.

With such a configuration, as shown in FIG. 14, the rotational speed of the engine 3 decreases below the threshold value with the intake air amount unchanged and the fuel injection amount unchanged, and this state continues for a predetermined period of time. In this case, the drive current correction unit 518 corrects the provisional drive current to increase. As a result, the drive current for the injector set by the drive current correction unit 518 increases, thereby preventing the engine 3 from stopping or decreasing the rotational speed.

FIG. 15 is a functional block diagram showing a second modification of the ECU 5 shown in FIG. 4. FIG. 16 is a flowchart illustrating the operation of the ECU 5 of modification 2 shown in FIG. 15. Processing P08H to processing P08J shown in FIG. 16, for example, in processing P085 or processing P086 of the failure detection processing P08 shown in FIG. This is carried out after the provisional drive current is set to the injector drive current by the drive current setting unit 507 during the period until the determination of the value abnormality.

In addition to the parts shown in FIG. 4, the electronic control device 5 of Modification 2 includes, for example, a valve closing state detection section 521, a valve closing time calculation section 522, and a drive current correction section 523 shown in FIG. ing. In process P08H shown in FIG. 16, the valve-closed state detection unit 521 detects the valve-closed state of the injector 29 and outputs it to the valve-closed time calculation unit 522. The valve closed state detection unit 521 detects the closed state of the injector 29 based on, for example, a signal output from the injector 29 when the injector 29 is closed. The valve closing time calculating section 522 calculates the observed value of the valve closing time of the injector 29 based on the valve closing state of the injector 29 inputted from the valve closing state detecting section 521. When calculating the observed valve closing state value, the valve opening time, which has an exclusive relationship with the observed valve closing time value, is also obvious, so calculate the observed valve opening time value in the same way as the observed valve closing time value above. can do.

Next, in process P08I, the drive current correction unit 523 determines whether the observed valve closing time value calculated by the valve closing time calculation unit 522 is longer than a predetermined valve closing time to be described later, and determines whether the valve closing time is If it is determined that the observed value is shorter than the predetermined valve closing time (NO), processing P08 shown in FIG. 10 is ended. On the other hand, in process P08I, if the drive current correction unit 523 determines that the observed value of the valve closing time calculated by the valve closing time calculation unit 522 is longer than the predetermined time (YES), the drive current correction unit 523 performs the failure etc. detection process shown in FIG. The provisional drive current set in process P085 or process P086 of P08 is corrected to increase.

Note that the process P08I described above can also be performed based on the observed valve opening time value. In this case, for example, the drive current correction unit 523 determines whether the observed valve opening time value calculated by the valve closing time calculation unit 522 is longer than a predetermined valve opening time, and determines whether the observed valve opening time value is If it is determined that the valve opening time is longer than the predetermined valve opening time (NO), processing P08 shown in FIG. 10 is ended. On the other hand, in process P08I, if the drive current correction unit 523 determines that the observed valve opening time value calculated by the valve opening time calculation unit 522 is shorter than the predetermined valve opening time (YES), the drive current correction unit 523 causes a failure as shown in FIG. The provisional drive current set in process P085 or process P086 of detection process P08 is corrected to increase. Note that the predetermined valve closing time and the predetermined valve opening time are, for example, the total fuel injection amount injected from the injector 29 or each fuel injection performed multiple times during one combustion cycle of the engine 3. It can be set based on the target fuel injection amount which is the injection amount.

FIG. 17 is a timing chart illustrating the operation of the ECU 5 of modification 2 shown in FIG. 15. In addition to each item of the timing chart shown in FIG. 14, the timing chart of FIG. 17 has a chart of valve closing time added. Further, the broken line in the fuel injection amount chart in FIG. 14 represents the target fuel injection amount.

As described above, the electronic control device 5 of this modification includes the valve closing state detection section 521, the valve closing time calculation section 522, and the drive current correction section 523. The valve closed state detection unit 521 detects the valve closed state of the injector 29. The valve closing time calculation unit 522 calculates the valve closing time or valve opening time of the injector 29 based on the detection result of the valve closed state. The drive current correction unit 523 increases the provisional drive current when the valve closing time of the injector 29 is longer than the predetermined valve closing time or when the valve opening time of the injector 29 is shorter than the predetermined valve opening time.

With such a configuration, the ECU 5 of the present modification 2 uses the valve closing detection function of the injector 29 to detect that the actual fuel injection amount (valve opening time observed value) of the injector 29 is decreasing. Can be done. That is, as shown in FIG. 17, when the observed value of the valve closing time of the injector 29 is longer than the predetermined valve closing time or when the observed value of the valve opening time of the injector 29 is shorter than the predetermined valve opening time, the injector 29 By detecting that the actual fuel injection amount is decreasing, it is possible to increase the provisional drive current output to the injector 29. As a result, the decrease in the fuel injection amount is eliminated, and it is possible to prevent the engine 3 from stopping and the rotational speed from decreasing.

FIG. 18 is a functional block diagram showing a third modification of the ECU 5 shown in FIG. 4. FIG. 19 is a flowchart illustrating the operation of the ECU 5 of modification 3 shown in FIG. 18. Processing P08K to processing P08O shown in FIG. 19, for example, in processing P085 or processing P086 of failure detection processing P08 shown in FIG. This is carried out after the provisional drive current is set by the drive current setting unit 507 during the period until the determination of the value abnormality.

In addition to the parts shown in FIG. 4, the ECU 5 of Modification 3 includes, for example, an intake air amount acquisition section 531, an intake air amount determination section 532, a fuel injection amount calculation section 533, and a fuel injection amount determination section shown in FIG. 534 and a drive current correction section 535. In process P08K shown in FIG. 19, the intake air amount acquisition unit 531 calculates and acquires the intake air amount based on the signal input from the intake sensor 11, for example.

Next, in process P08L, the intake air amount determining unit 532 determines whether the amount of change in the intake air amount is within a predetermined range, based on the time series data of the intake air amount, and If it is determined (NO), the process P08 is ended. On the other hand, in this process P08L, when the intake air amount determining section 532 determines that the intake air amount is within the predetermined range (YES), the fuel injection amount calculating section 533 calculates, for example, signals input from various sensors of the engine system ES. Based on this, a process P08M is executed to calculate the total amount of fuel injected from the injector 29.

Next, in process P08N, the fuel injection amount determining unit 534 determines whether the amount of change in the total fuel injection amount is within a predetermined range based on the time series data of the fuel injection amount, and determines whether or not the amount of change in the total fuel injection amount is within a predetermined range (NO ), the process P08 is ended. On the other hand, if it is determined in this process P08N that the amount of change in the total fuel injection amount is outside the predetermined range (NO), the ECU 5 executes the next process P08O. In this process P08O, the drive current correction section 535 corrects the provisional drive current output to the injector 29 to increase it, and the drive current setting section 507 changes the provisional drive current after the correction by the drive current correction section 535 to a new value. Set to temporary drive current.

FIG. 20 is a timing chart illustrating the operation of the ECU 5 of the third modification shown in FIG. 18. In the timing chart of FIG. 20, a chart of intake air amount and fuel injection amount is added in place of the engine speed chart shown in FIG. 6.

As described above, the electronic control device 5 of the third modification includes the intake air amount acquisition section 531, the fuel injection amount calculation section 533, and the drive current correction section 535. The intake air amount acquisition unit 531 acquires the intake air amount of the engine 3. The fuel injection amount calculation unit 533 calculates the fuel injection amount of the injector 29 when the amount of change in the intake air amount is within a predetermined range. The drive current correction unit 535 corrects the provisional drive current to increase when the total fuel injection amount is decreasing.

For example, when the total fuel injection amount suddenly decreases, the amount of fuel discharged from the high-pressure fuel pump 25 to the injector 29 exceeds the amount of fuel injected from the injector 29 into the combustion chamber, causing the fuel pressure in the common rail 27 to increase. However, this increase in fuel pressure cannot be detected in a situation where a failure of the fuel pressure sensor 28 or an abnormality in the detected value is detected. However, according to the configuration of modification 3, as shown in FIG. 20, when it is detected that the amount of change in the fuel injection amount is outside the predetermined range, the provisional drive current output to the injector 29 can be increased. . As a result, the engine 3 is prevented from stopping or from decreasing in rotational speed due to an increase in fuel pressure.

Although the embodiments and modifications thereof of the electronic control device according to the present disclosure have been described above in detail using the drawings, the specific configuration is not limited to these embodiments and modifications, and the embodiments of the present disclosure are not limited to the embodiments and modifications thereof. Even if there are design changes within the scope of the invention, they are included in the present disclosure.

21 Fuel tank 22 Low pressure fuel pump 24 Low pressure fuel supply passage (low pressure fuel supply pipe)
25 High pressure fuel pump 28 Fuel pressure sensor 29 Injector 3 Engine 31 Combustion chamber 5 ECU (electronic control unit)
501 Target fuel pressure calculation section 502 Fuel pressure acquisition section 503 Failure detection section 504 Failure determination section 505 Abnormality detection section 506 Abnormality determination section 507 Drive current setting section 509 High pressure fuel pump control section 512 Fuel injection amount calculation section 514 Intake air amount acquisition section 516 Engine Rotation speed acquisition section 518 Drive current correction section 521 Valve closing state detection section 522 Valve closing time calculation section 523 Drive current correction section 531 Intake air amount acquisition section 533 Fuel injection amount calculation section 535 Drive current correction section ES Engine system FPs Fuel pressure detection value FPt Target fuel pressure TP1 First period TP2 Second period

Claims

An electronic control device that controls an engine system including an injector that injects fuel into a combustion chamber of an engine, and a fuel pressure sensor that detects the fuel pressure of the fuel supplied to the injector,
a target fuel pressure calculation unit that calculates a target fuel pressure of the fuel supplied to the injector;
a fuel pressure acquisition unit that acquires a fuel pressure detection value of the fuel pressure sensor;
a failure detection unit that detects a failure of the fuel pressure sensor, which is a failure of the fuel pressure sensor, based on the detected fuel pressure value;
a failure determination unit that determines a failure determination of the fuel pressure sensor when detection of the fuel pressure sensor failure continues beyond a first period;
an abnormality detection unit that detects an abnormality in the detected fuel pressure value based on the difference between the target fuel pressure and the detected fuel pressure value and the amount of change in the detected fuel pressure value per unit time;
an abnormality determination unit that determines the detected value abnormality of the fuel pressure detected value when the detected value abnormality of the fuel pressure detected value continues beyond a second period;
a drive current setting unit that sets a drive current for the injector according to the fuel pressure of the fuel,
The drive current setting unit sets the fuel pressure sensor failure as a drive current for the injector during a period from detection of the fuel pressure sensor failure or detection of the detected value abnormality to determination of the fuel pressure sensor failure or determination of the detected value abnormality. and setting a provisional drive current according to the detected fuel pressure value at a time before the detected value abnormality is detected.
The electronic control device according to claim 1, wherein the drive current setting unit gradually reduces the drive current of the injector from the provisional drive current when the fuel pressure sensor failure or the detected value abnormality is confirmed. .
The engine system includes a high-pressure fuel pump that sucks the fuel and discharges the fuel under pressure to the injector, a low-pressure fuel supply passage that bypass-connects the suction side and discharge side of the high-pressure fuel pump, and supplies the low-pressure fuel from the fuel tank. a supply passage and a low-pressure fuel pump that supplies the fuel to the suction side of the high-pressure fuel pump,
The electronic control device is configured to stop the pressurized discharge of the fuel by the high-pressure fuel pump when the fuel pressure sensor failure or the detected value abnormality is confirmed, thereby causing the low-pressure fuel pump to operate the low-pressure fuel supply passage. a high-pressure fuel pump control unit configured to supply the fuel to the injector via the injector;
The drive current setting unit changes the drive current of the injector from the provisional drive current to the amount of fuel supplied to the injector by the low-pressure fuel pump when the fuel pressure sensor failure or the detected value abnormality is confirmed. 3. The electronic control device according to claim 2, wherein the electronic control device gradually decreases the fuel pressure to a predetermined set value corresponding to the fuel pressure value.
The provisional drive current is the higher value of the most recent fuel pressure detection value and the fuel pressure detection value at a time a third period has passed since the time when the fuel pressure sensor failure was detected or the detected value abnormality was detected. 2. The electronic control device according to claim 1, wherein the electronic control device is set based on a detected fuel pressure value.
The drive current setting unit is configured to set a drive current for the injector calculated based on a fuel pressure detection value at a point in time after a third period from the time when the fuel pressure sensor failure or the detection value abnormality was detected, and the most recent fuel pressure. 2. The electronic control device according to claim 1, wherein the provisional drive current is set to a larger one of the injector drive currents calculated based on the detected value.
a fuel injection amount calculation unit that calculates a fuel injection amount of the injector;
an intake air amount acquisition unit that acquires the intake air amount of the engine when the amount of change in the fuel injection amount is within a predetermined range;
an engine rotation speed acquisition unit that acquires the rotation speed of the engine;
If the rotational speed of the engine is considered to be lower than a predetermined rotational speed during the period from the detection of a failure of the fuel pressure sensor or the abnormality of the detected value to the determination of the failure of the fuel pressure sensor or the determination of the abnormality of the detected value; 2. The electronic control device according to claim 1, further comprising a provisional drive current correction unit that corrects the provisional drive current so as to increase the provisional drive current.
a target fuel injection amount calculation unit that calculates a total fuel injection amount of the injector according to the intake air amount of the engine; and an opening that defines a valve opening time length for opening the fuel injection valve according to the total fuel injection amount. a valve time length calculation section;
a valve closed state detection unit that detects a valve closed state of the injector;
Calculate an observed valve closing time value or an observed valve opening time value of the injector based on the valve closing state of the injector, and set a predetermined valve closing time or a predetermined valve opening time according to the valve opening time length. and a valve closing time calculation section,
The provisional drive current is increased when the observed value of the valve closing time of the injector is longer than the predetermined valve closing time, or when the observed value of the valve opening time of the injector is shorter than the predetermined valve opening time. The electronic control device according to claim 1, further comprising a drive current correction section that corrects the drive current.
an intake air amount acquisition unit that acquires the intake air amount of the engine;
a fuel injection amount calculation unit that calculates a total fuel injection amount of the injector based on the intake air amount;
If the fuel injection amount is lower than a predetermined value during the period from detection of a failure of the fuel pressure sensor or abnormality of the detected value to determination of the failure of the fuel pressure sensor or determination of the abnormality of the detected value, the provisional drive current The electronic control device according to claim 1, further comprising a drive current correction section that corrects the drive current so as to increase the drive current.
The drive current correction unit adjusts the amount of change in the total fuel injection amount per unit time during a period from detection of a failure of the fuel pressure sensor or abnormality of the detected value to determination of the failure of the fuel pressure sensor or determination of the abnormality of the detected value. The electronic control device according to claim 8, wherein the provisional drive current is corrected based on.