WO2010050289A1 - Procédé de diagnostic de capteur de pression et dispositif de commande d'injection de combustible de type à rampe commune - Google Patents

Procédé de diagnostic de capteur de pression et dispositif de commande d'injection de combustible de type à rampe commune Download PDF

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Publication number
WO2010050289A1
WO2010050289A1 PCT/JP2009/065035 JP2009065035W WO2010050289A1 WO 2010050289 A1 WO2010050289 A1 WO 2010050289A1 JP 2009065035 W JP2009065035 W JP 2009065035W WO 2010050289 A1 WO2010050289 A1 WO 2010050289A1
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WO
WIPO (PCT)
Prior art keywords
pressure
pressure sensor
piezo injector
common rail
predetermined
Prior art date
Application number
PCT/JP2009/065035
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English (en)
Japanese (ja)
Inventor
栄 須田
博隆 金子
Original Assignee
ボッシュ株式会社
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Publication date
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Priority to JP2010535717A priority Critical patent/JP5220122B2/ja
Publication of WO2010050289A1 publication Critical patent/WO2010050289A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D41/2096—Output circuits, e.g. for controlling currents in command coils for controlling piezoelectric injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2051—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit using voltage control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/06—Fuel or fuel supply system parameters
    • F02D2200/0602—Fuel pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/06—Fuel or fuel supply system parameters
    • F02D2200/0602—Fuel pressure
    • F02D2200/0604—Estimation of fuel pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
    • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
    • F02M63/0275—Arrangement of common rails
    • F02M63/028—Returnless common rail system

Definitions

  • the present invention relates to abnormality diagnosis of a sensor operation, and more particularly, to the realization of abnormality diagnosis with a simple configuration without using dedicated parts.
  • an electronic control device for an internal combustion engine of an automobile typified by a diesel engine
  • various sensors are provided, and detection signals thereof are used for operation control of the internal combustion engine.
  • a pressure sensor for detecting a rail pressure in a common rail fuel injection control device is important for realizing appropriate fuel injection, and various measures for detecting a failure have been proposed. .
  • the present invention has been made in view of the above circumstances, and a pressure sensor capable of diagnosing the presence or absence of an abnormality with a simple configuration without providing a dedicated circuit for diagnosing the operation of the abnormality or failure of the pressure sensor.
  • a diagnostic method and a common rail fuel injection control device are provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a pressure sensor diagnosis method in a common rail fuel injection control device wherein the common rail pressure is controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail.
  • a standard rail pressure to be generated with respect to a change in the section is obtained based on a predetermined correlation between the predetermined change in the terminal voltage and the standard rail pressure, When the difference between the detected rail pressure obtained by the pressure sensor and the standard rail pressure obtained based on the predetermined correlation is greater than a predetermined threshold, the pressure sensor is determined to be abnormal.
  • a pressure sensor diagnostic method is provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a common rail fuel injection control device configured to be controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail by an electronic control unit.
  • the electronic control unit is Applying a predetermined drive current to the piezo injector for a predetermined drive time, acquiring a change in a predetermined section of the terminal voltage of the piezo injector that occurs during the energization period, and determining the predetermined terminal voltage of the acquired piezo injector
  • a standard rail pressure to be generated for a change in the section is calculated based on a predetermined correlation between the predetermined change in the terminal voltage and the standard rail pressure, It is determined whether the difference between the detected rail pressure obtained by the pressure sensor and the standard rail pressure obtained based on a predetermined correlation is greater than a predetermined threshold, and the detection obtained by the pressure sensor
  • a common rail fuel configured to determine that the pressure sensor is abnormal when it is determined that the difference between the rail pressure and the standard rail pressure obtained based on a predetermined correlation is greater than a predetermined threshold.
  • An injection control device is provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a pressure sensor diagnosis method in a common rail fuel injection control device wherein the common rail pressure is controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail.
  • Pressure sensor diagnosis configured to determine whether or not there is an abnormality in the pressure sensor based on a first peak voltage in the pulsation of the terminal voltage generated after the start of energization of the piezo injector and a terminal voltage at the end of energization of the piezo injector.
  • a method is provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a common rail fuel injection control device configured to be controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail by an electronic control unit.
  • the electronic control unit is A common rail type configured to determine the presence or absence of abnormality of the pressure sensor based on the first peak voltage in the pulsation of the terminal voltage generated after the start of energization of the piezo injector and the terminal voltage at the end of energization of the piezo injector.
  • a fuel injection control device is provided. According to the fifth aspect of the present invention, the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a pressure sensor diagnosis method in a common rail fuel injection control device wherein the common rail pressure is controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail.
  • the pressure sensor is configured to determine whether or not the pressure sensor is abnormal based on a terminal voltage of the piezo injector at the end of energization of the piezo injector and a target voltage of the terminal voltage of the piezo injector at the end of energization.
  • a pressure sensor diagnostic method is provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high pressure pump, and the high pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a common rail fuel injection control device configured to be controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail by an electronic control unit.
  • the electronic control unit is Obtaining the terminal voltage of the piezo injector at the end of energization to the piezo injector, and based on the obtained terminal voltage of the piezo injector and the target voltage of the terminal voltage of the piezo injector at the end of energization of the piezo injector
  • a common rail fuel injection control device configured to determine whether or not the pressure sensor is abnormal.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high-pressure pump, and the high-pressure fuel is supplied to the internal combustion engine through the fuel injection valve using the piezo injector connected to the common rail.
  • the pressure of the common rail is configured to be controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail, and the piezo injector has a terminal voltage at the end of energization.
  • Is a pressure sensor diagnostic method configured such that the applied voltage of the piezo injector is corrected and driven to be controlled so as to be a predetermined target voltage
  • a pressure sensor diagnosis method configured to determine whether or not the pressure sensor is abnormal when a correction amount of an applied voltage at the end of energization of the piezo injector exceeds a predetermined amount.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high pressure pump, and the high pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • the common rail pressure can be controlled by the electronic control unit based on a detection signal of a pressure sensor for detecting the pressure of the common rail, and when the energization of the piezo injector is completed.
  • a common rail fuel injection control device configured to control the drive of the piezo injector by correcting the applied voltage of the piezo injector so that the terminal voltage at is a predetermined target voltage,
  • the electronic control unit is It is determined whether the correction amount of the applied voltage at the end of energization of the piezo injector exceeds a predetermined amount, and when it is determined that the correction amount of the applied voltage at the end of energization of the piezo injector exceeds a predetermined amount,
  • a common rail fuel injection control device configured to determine that a pressure sensor is abnormal is provided.
  • the fuel in the fuel tank is pressurized and pumped to the common rail by the high pressure pump, and the high pressure fuel is supplied to the internal combustion engine via the fuel injection valve using the piezo injector connected to the common rail.
  • a pressure sensor diagnosis method in a common rail fuel injection control device wherein the common rail pressure is controllable based on a detection signal of a pressure sensor that detects the pressure of the common rail.
  • a pressure sensor diagnostic method configured to determine whether or not there is an abnormality in the pressure sensor based on a change in the terminal voltage within a predetermined section in the pulsation of the terminal voltage that occurs after the start of energization of the piezo injector.
  • the original rail pressure should be obtained based on the correlation between the change in the terminal voltage of the piezo injector and the rail pressure, and the detection of the pressure sensor Since it is now possible to detect whether there is an abnormality in the pressure sensor by comparing it with the pressure, it is possible to detect the abnormality of the pressure sensor with a simple configuration by software without newly providing a dedicated circuit for diagnosing the presence of abnormality. As a result, it is possible to provide a highly reliable common rail fuel injection control device by applying such a diagnostic method.
  • the third to ninth aspects of the present invention it is possible to detect the presence or absence of abnormality of the pressure sensor based on the correlation between the terminal voltage and the rail pressure at a predetermined timing when the piezo injector is driven. Therefore, it is possible to realize an abnormality detection of the pressure sensor with a simple configuration by software without newly providing a dedicated circuit for diagnosing the presence / absence of an abnormality, and to apply such a diagnosis method Thus, there is an effect that a highly reliable common rail fuel injection control device can be provided.
  • FIG. 1 It is a block diagram which shows the example of 1 structure of the common rail type fuel-injection control apparatus to which the pressure sensor diagnostic method in embodiment of this invention is applied.
  • the subroutine which shows the whole procedure in the 1st structural example of the pressure sensor diagnostic process in the 1st and 9th form of this invention performed by the electronic control unit which comprises the common rail type fuel-injection control apparatus shown by FIG. It is a flowchart. It is a subroutine flowchart which shows the specific process sequence of the diagnostic process performed in the pressure sensor diagnostic process shown by FIG. It is a subroutine flowchart which shows the specific process sequence of the last diagnostic process performed in the pressure sensor diagnostic process shown by FIG.
  • FIGS. 1 a configuration example of an internal combustion engine injection control apparatus to which the pressure sensor diagnosis method according to the first and ninth embodiments of the present invention is applied will be described with reference to FIG.
  • the internal combustion engine injection control device shown in FIG. 1 is particularly configured as a common rail fuel injection control device.
  • This common rail fuel injection control device includes a high pressure pump device 50 that pumps high pressure fuel, a common rail 1 that stores the high pressure fuel pumped by the high pressure pump device 50, and a high pressure fuel supplied from the common rail 1 as a diesel engine.
  • a plurality of fuel injection valves 2-1 to 2-n (hereinafter referred to as “engine”) for supplying fuel to three cylinders, and an electronic control unit for executing a fuel injection control process, a pressure sensor diagnosis process (to be described later), and the like (FIG. 1)
  • the main component is “ECU”.
  • Such a configuration itself is the same as the basic configuration of this type of fuel injection control apparatus that has been well known.
  • the high-pressure pump device 50 has a known and well-known configuration in which the supply pump 5, the metering valve 6, and the high-pressure pump 7 are configured as main components.
  • the fuel in the fuel tank 9 is pumped up by the supply pump 5 and supplied to the high-pressure pump 7 through the metering valve 6.
  • the metering valve 6 an electromagnetic proportional control valve is used, and the amount of energization is controlled by the electronic control unit 4, so that the flow rate of fuel supplied to the high-pressure pump 7, in other words, the discharge of the high-pressure pump 7. The amount is to be adjusted.
  • a return valve 8 is provided between the output side of the supply pump 5 and the fuel tank 9 so that surplus fuel on the output side of the supply pump 5 can be returned to the fuel tank 9. .
  • the supply pump 5 may be provided separately from the high-pressure pump device 50 on the upstream side of the high-pressure pump device 50 or may be provided in the fuel tank 9.
  • the fuel injection valves 2-1 to 2-n are provided for each cylinder of the engine 3, and are supplied with high-pressure fuel from the common rail 1 and perform fuel injection by injection control by the electronic control unit 4. Yes.
  • the fuel injection valves 2-1 to 2-n are made using piezo injectors.
  • Such a piezo injector (not shown) is not unique to the present invention, and has a conventional configuration.
  • the electronic control unit 4 controls the driving of the piezo injector, and the high pressure applied to the cylinders of the engine 3. It is possible to inject fuel.
  • the piezo injector generally has a configuration in which the injection holes (not shown) of the fuel injection valves 2-1 to 2-n are opened by application of a drive voltage. In the embodiment of the present invention, Is also assumed to have such a configuration.
  • the drive control of such a piezo injector is generally roughly divided into two forms (control patterns). That is, in one of the two control patterns, the drive voltage of the fuel injectors 2-1 to 2-n is set for each rail pressure, and the fuel injector 2-1 is driven with the drive voltage corresponding to the rail pressure. ⁇ 2-n is driven.
  • Such a control pattern is referred to as a “drive voltage selection type” for convenience.
  • the other control pattern is to drive the fuel injection valves 2-1 to 2-n with a predetermined drive voltage regardless of the rail pressure.
  • the predetermined drive voltage is a drive voltage that enables injection at the maximum rail pressure, and a value obtained in advance by a test or the like is set.
  • Such a control pattern is referred to as a “driving voltage fixed type” for convenience. Which control pattern is to be selected should be determined in consideration of the type of vehicle and the displacement.
  • the electronic control unit 4 has, for example, a microcomputer (not shown) having a known and well-known configuration, a storage element (not shown) such as a RAM and a ROM, and a fuel injection valve 2-
  • a circuit (not shown) for energizing and driving 1 to 2-n and a circuit (not shown) for energizing and driving the metering valve 6 and the like are configured as main components.
  • various detection signals such as the engine speed, the accelerator opening, the engine coolant temperature, and the fuel temperature are received from the engine. 3 is input to be used for operation control 3 and fuel injection control.
  • the electronic control unit 4 is adapted to read the terminal voltage of the piezo injector that is required in the pressure sensor diagnosis processing in the embodiment of the present invention to be described later.
  • FIG. 2 shows an overall procedure of pressure sensor diagnosis processing in the first configuration example in a subroutine flowchart, and the contents thereof will be described below with reference to FIG.
  • the pressure sensor diagnosis process in the embodiment of the present invention is executed variously for the vehicle operation control in the electronic control unit 4 and is subjected to a subroutine process as one of the control processes.
  • the pressure sensor diagnosis process by the electronic control unit 4 is started, first, whether or not the operation state of the vehicle is suitable for performing pressure sensor diagnosis, that is, whether or not the operating state of the engine 3 is stable.
  • a determination process for determining whether or not the vehicle is in an overrun state is performed (see steps S102 to S112 in FIG. 2).
  • the electronic control unit 4 acquires the engine coolant temperature change ⁇ Tc (see step S102 in FIG. 2). That is, based on the engine cooling water temperature input to the electronic control unit 4, the amount of change in the engine cooling water temperature in a predetermined unit time (for example, every minute) is calculated and calculated. Next, it is determined whether or not the water temperature change amount ⁇ Tc acquired by the calculation is smaller than the predetermined water temperature change amount K1 (see step S104 in FIG. 2). If it is determined that the water temperature change amount ⁇ Tc is smaller than the predetermined water temperature change amount K1 (YES) In the case), the process by the electronic control unit 4 proceeds to the process of step S106 described below.
  • step S104 the electronic control unit 4 causes the engine coolant temperature change amount not to be smaller than the predetermined water temperature change amount K1, in other words, the engine coolant water temperature change amount exceeds the predetermined water temperature change amount K1.
  • step S106 the fuel temperature change amount ⁇ Tf is acquired by the electronic control unit 4. That is, based on the fuel temperature input to the electronic control unit 4, the fuel temperature change amount (fuel temperature change amount) ⁇ Tf in a predetermined unit time (for example, one minute interval) is calculated and calculated. Next, it is determined whether or not the fuel temperature change amount ⁇ Tf acquired by calculation is smaller than the predetermined fuel temperature change amount K2 (see step S108 in FIG. 2), and it is determined that the fuel temperature change amount ⁇ Tf is smaller than the predetermined fuel temperature change amount K2. In the case of (YES), the process by the electronic control unit 4 proceeds to the process of step S110 described below.
  • step S108 the electronic control unit 4 determines that the fuel temperature change amount ⁇ Tf is not smaller than the predetermined fuel temperature change amount K2, in other words, the fuel temperature change amount exceeds the predetermined fuel temperature change amount K2.
  • NO in the case of NO
  • the series of processing is terminated assuming that the operation state of the vehicle is not suitable for performing pressure sensor diagnosis, and the process returns to the main routine (not shown).
  • step S110 the accelerator opening detection signal is read into the electronic control unit 4, and then the accelerator opening Acc is 0%, that is, whether the accelerator (not shown) is not depressed. Is determined (see step S112 in FIG. 2). And in step S112, when it is determined by the electronic control unit 4 that the accelerator opening degree Acc is 0% (in the case of YES), it is determined that the vehicle is in an overrun state, and the processing of the electronic control unit 4 is as follows. Proceeding to step S200, a diagnostic process described below is executed, and thereafter, the process once returns to a main routine (not shown).
  • the drive control pattern of the fuel injection valves 2-1 to 2-n by the electronic control unit 4 is a drive voltage selection type.
  • the vehicle operating state is an overrun state, that is, in a state where the accelerator (not shown) is not stepped on, in other words, in a state where the accelerator opening is zero, This is because it is considered that performing the diagnosis process minimizes the influence on the vehicle operation and does not give the driver a sense of incongruity.
  • the fuel injection valves 2-1 to 2-n in the diagnosis process is set to be relatively high, depending on the operating state of the vehicle, the fuel injection valve by the diagnosis process This is because injection due to energization of 2-1 to 2-n may cause a large fluctuation in the engine speed, and may cause discomfort to the driver and passengers.
  • FIG. 3 shows a specific processing procedure of the diagnostic processing in a subroutine flowchart.
  • the specific processing procedure will be described with reference to FIG.
  • the series of processing shown in FIG. 3 is executed for each of the fuel injection valves 2-1 to 2-n. That is, the series of processing shown in FIG. 3 is executed for each fuel injection valve 2-1 to 2-n in a predetermined order.
  • the result of the diagnosis processing in each of the fuel injection valves 2-1 to 2-n is comprehensively determined, and finally This is because it is determined whether or not the pressure sensor 11 is abnormal.
  • FIG. 6 shows an example of the time change of the terminal voltage when the fuel injection valves 2-1 to 2-n are energized and driven.
  • the horizontal axis represents the elapsed time from the start of energization
  • the vertical axis represents the voltage, Represents each.
  • a characteristic line represented by a two-dot chain line shows an example of a voltage change in a normal driving state of the fuel injection valves 2-1 to 2-n.
  • a characteristic line represented by a solid line indicates a voltage change when the fuel injection valves 2-1 to 2-n are driven by the drive current Is.
  • the inventor of the present application in the so-called pulsation in which the terminal voltage of the piezo injector changes up and down after the start of energization, the first peak value (the voltage value at the time t1 in FIG. 6) and the first peak value (hereinafter referred to as the peak value)
  • the difference from the second peak value (voltage value at the time t2 in FIG. 6) when the voltage starts to decrease after the voltage decrease after “first peak value”) is a constant correlation with the rail pressure. It led to the conclusion that there is a relationship, and specifically, it is roughly proportional.
  • a predetermined drive current is supplied to the piezo injector for a predetermined drive time
  • a change in a predetermined interval of the terminal voltage of the piezo injector that occurs during the period is acquired, and a standard rail pressure to be generated with respect to the change in the predetermined interval of the terminal voltage of the piezo injector is determined by a predetermined piezo injector
  • the detected rail pressure obtained by the pressure sensor 11 based on a predetermined correlation between the change in the terminal voltage in the predetermined section and the standard rail pressure, and the standard rail pressure obtained based on the previous predetermined correlation It can be said that the presence or absence of abnormality of the pressure sensor 11 is diagnosed based on the difference between the two.
  • the piezo injector is turned on.
  • the first peak voltage (first peak voltage) V1 of the terminal voltage is detected by the electronic control unit 4, and the value is provisionally read into a predetermined storage area (not shown) in the electronic control unit 4. (See step S204 in FIG. 3).
  • the first peak voltage V1 is the voltage at the time t1 in the solid characteristic line of the voltage change illustrated in FIG.
  • the second peak voltage V2 is read in the same manner (see step S206 in 3). That is, the terminal voltage of the piezo injector once decreases after reaching the first peak voltage V1 (see FIG. 6), decreases to some extent, then starts increasing again, and the first peak voltage It becomes a peak at a voltage V2 lower than V1 (see the location at time t2 in FIG. 6), and shows a change that begins to fall again. If the piezo injector is normal, these changes usually appear within a predetermined energization time ET.
  • the predetermined energization time ET is preferably set to an appropriate value based on the test and simulation results together with the predetermined drive current Is.
  • the second peak voltage is detected by the electronic control unit 4 and temporarily stored in a predetermined storage area (not shown) in the electronic control unit 4.
  • step S208 the process of the electronic control unit 4 proceeds to the process of step S208, and the potential difference ⁇ V between the first peak voltage V1 and the second peak voltage V2 is calculated and calculated.
  • potential difference / rail pressure conversion processing is performed based on the potential difference calculated as described above (see step S210 in FIG. 3).
  • the potential difference ⁇ V between the first peak voltage V1 and the second peak voltage is: This is based on the correlation with the rail pressure at that time.
  • the correlation between the potential difference ⁇ V and the rail pressure is obtained in advance, and this is mapped, for example, stored in a predetermined storage area (not shown) of the electronic control unit 4, and obtained in step S208. It is preferable that the original rail pressure (standard rail pressure) Pv to be obtained at that time is obtained with respect to the potential difference ⁇ V. It is preferable that the rail pressure Pv with respect to a certain potential difference ⁇ V can be obtained by converting the correlation into an arithmetic expression instead of mapping and using the arithmetic expression.
  • the sensor detection pressure Pac is acquired by the electronic control unit 4 (see step S212 in FIG. 3). That is, the detection signal of the pressure sensor 11 is input to the electronic control unit 4, but the electronic control unit 4 is predetermined based on the input detection signal of the pressure sensor 11.
  • a rail pressure (detected rail pressure) Pac corresponding to the detection signal is determined by an arithmetic expression or a map.
  • L is referred to as “absolute pressure difference” for convenience of explanation.
  • step S216 when the electronic control unit 4 determines in step S216 that the absolute pressure difference L exceeds the predetermined threshold (in the case of YES), the pressure sensor 11 is abnormal (sensor abnormality). (See step S218 in FIG. 3), the series of processing is terminated, and the processing in the electronic control unit 4 once returns to the main routine (not shown).
  • the determination that the sensor is abnormal in step S218 is a result of executing the above-described series of diagnostic processing on one of the fuel injection valves 2-1 to 2-n.
  • the correlation between the difference ⁇ V between the first peak voltage V1 and the second peak voltage V2 and the standard rail pressure Pv is expressed as the standard rail pressure to be generated for a certain potential difference ⁇ V.
  • the ratio of the difference ⁇ V between the first peak voltage V1 and the second peak voltage V2 to the first peak voltage V1, that is, ⁇ V / V1 and the rail pressure (standard rail pressure) A correlation is also established between the two.
  • step S210 of FIG. 3 the pressure sensor 11 can be diagnosed by performing the same processing from step S214 onward in FIG.
  • the final diagnosis process will be described with reference to the subroutine flowchart shown in FIG.
  • the series of processes shown in FIG. 3 is performed for each of the fuel injection valves 2-1 to 2 -n, in other words, for the engine 3. Even if it is determined that there is a sensor abnormality by the diagnostic processing in that one fuel injection valve, the corresponding processing such as abnormality notification is not immediately performed. As described below, whether or not abnormality notification is necessary is selected in the final diagnosis process.
  • the processing is started by the electronic control unit 4, first, the previous fuel injectors 2-1 to 2-n stored in a predetermined storage area (not shown) of the electronic control unit 4 are stored.
  • the results J1 to Jn of the diagnosis process shown in FIG. 3 are read (see steps S216 and S218 in FIG. 3 and step S302 in FIG. 4).
  • the number that the diagnosis result is a sensor abnormality is counted by the electronic control unit 4, and the count value of the abnormality diagnosis number N is determined (see step S304 in FIG. 4).
  • the electronic control unit 4 determines whether or not the count value N is greater than the predetermined reference count value Ns (see step S306 in FIG. 4), and the count value N is not greater than the predetermined reference count value Ns. Is determined (NO), the pressure sensor 11 is not abnormal and a series of processes are terminated, and the process returns to a main routine (not shown). On the other hand, when the electronic control unit 4 determines in step S306 that the count value N is greater than the predetermined reference count value Ns (in the case of YES), the electronic control unit determines that the pressure sensor 11 is abnormal. 4 is notified of abnormality (see step S308 in FIG. 4). In addition, although it is suitable for abnormality notification to generate
  • FIG. 5 is a subroutine flowchart showing the overall procedure of the pressure sensor diagnosis process in the second configuration example.
  • the overall procedure of the pressure sensor diagnosis process in the first configuration example is shown.
  • the only difference from the subroutine flowchart of FIG. 2 is that the processing of steps S110 and S112 in FIG. 2 is omitted.
  • steps having the same processing contents as those in FIG. 2 are denoted by the same step numbers, and detailed description thereof is omitted.
  • Step S200 the diagnostic processing by the electronic control unit 4 (FIG. 5). Step S200) is executed. Note that the specific contents of the diagnosis processing are as described above with reference to FIGS. 3 and 4, and therefore detailed description thereof is omitted here.
  • the change in the terminal voltage becomes such a state that the pressure sensor 11 is determined to be abnormal by the above-described pressure sensor diagnosis process even though the pressure sensor 11 is normal.
  • a process of diagnosing the presence or absence of aging deterioration of the piezo injector is executed, and a misdiagnosis that makes the pressure sensor 11 caused by aging deterioration of the piezo injector abnormal is performed. It is also preferable to avoid the occurrence.
  • the electronic control unit 4 acquires the above-described potential difference ⁇ V between the first peak voltage and the second peak voltage, and the storage element ( (When not shown), when a new potential difference ⁇ V is acquired, it is compared with the latest ⁇ V stored in the storage element, and the difference is a predetermined threshold value. If it is A or less, the pressure sensor diagnosis process (see step S200 in FIG. 2) is executed on the assumption that even if there is an aging of the piezo injector, it does not affect the diagnosis result of the pressure sensor diagnosis process.
  • predetermined threshold A a predetermined threshold B greater than the predetermined threshold A (predetermined threshold A ⁇ predetermined threshold B)
  • pressure sensor diagnosis processing (see step S200 in FIG. 2) is performed. Therefore, the execution of the pressure sensor diagnosis process is postponed.
  • predetermined threshold A a relatively small value (small value)
  • setting the predetermined threshold B to a relatively large value, it is possible to detect the possibility of aging deterioration of the piezo injector. is there.
  • the above-described diagnosis process for the presence or absence of aging deterioration of the piezo injector is performed when YES is determined in step S112 in FIG. 2 or when YES is determined in step S108 in FIG.
  • the process is performed immediately before the execution of the process of S200, the present invention is not limited to this.
  • the process is performed before the process of step S102 of FIG. 2 or FIG. If it is determined that it does not affect the diagnosis result of the pressure sensor diagnosis process, the process after step S102 may be executed.
  • FIGS. 1 and 7 to 12 The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
  • the pressure sensor diagnosis method according to the embodiment of the present invention is suitable for being applied to an internal combustion engine injection control apparatus having the configuration described above with reference to FIG.
  • the configuration of the internal combustion engine injection control apparatus shown in FIG. 1 will be described again.
  • the internal combustion engine injection control device shown in FIG. 1 is particularly configured as a common rail fuel injection control device.
  • This common rail fuel injection control device includes a high pressure pump device 50 that pumps high pressure fuel, a common rail 1 that stores the high pressure fuel pumped by the high pressure pump device 50, and a high pressure fuel supplied from the common rail 1 as a diesel engine.
  • a plurality of fuel injection valves 2-1 to 2-n (hereinafter referred to as “engine”) for supplying fuel to three cylinders, and an electronic control unit for executing a fuel injection control process, a pressure sensor diagnosis process (to be described later), and the like (FIG. 1)
  • the main component is “ECU”.
  • Such a configuration itself is the same as the basic configuration of this type of fuel injection control apparatus that has been well known.
  • the high-pressure pump device 50 has a known and well-known configuration in which the supply pump 5, the metering valve 6, and the high-pressure pump 7 are configured as main components.
  • the fuel in the fuel tank 9 is pumped up by the supply pump 5 and supplied to the high-pressure pump 7 through the metering valve 6.
  • the metering valve 6 an electromagnetic proportional control valve is used, and the amount of energization is controlled by the electronic control unit 4, so that the flow rate of fuel supplied to the high-pressure pump 7, in other words, the discharge of the high-pressure pump 7. The amount is to be adjusted.
  • a return valve 8 is provided between the output side of the supply pump 5 and the fuel tank 9 so that surplus fuel on the output side of the supply pump 5 can be returned to the fuel tank 9. .
  • the supply pump 5 may be provided separately from the high-pressure pump device 50 on the upstream side of the high-pressure pump device 50 or may be provided in the fuel tank 9.
  • the fuel injection valves 2-1 to 2-n are provided for each cylinder of the engine 3, and are supplied with high-pressure fuel from the common rail 1 and perform fuel injection by injection control by the electronic control unit 4. Yes.
  • the fuel injection valves 2-1 to 2-n are made using piezo injectors.
  • Such a piezo injector (not shown) is not unique to the present invention, and has a conventional configuration.
  • the electronic control unit 4 controls the driving of the piezo injector, and the high pressure applied to the cylinders of the engine 3. It is possible to inject fuel.
  • the piezo injector generally has a configuration in which the injection holes (not shown) of the fuel injection valves 2-1 to 2-n are opened by application of a drive voltage. In the embodiment of the present invention, Is also assumed to have such a configuration.
  • the drive control of such a piezo injector is generally roughly divided into two forms (control patterns). That is, in one of the two control patterns, the drive voltage of the fuel injectors 2-1 to 2-n is set for each rail pressure, and the fuel injector 2-1 is driven with the drive voltage corresponding to the rail pressure. ⁇ 2-n is driven.
  • Such a control pattern is referred to as a “drive voltage selection type” for convenience.
  • the other control pattern is to drive the fuel injection valves 2-1 to 2-n with a predetermined drive voltage regardless of the rail pressure.
  • the predetermined drive voltage is a drive voltage that enables injection at the maximum rail pressure, and a value obtained in advance by a test or the like is set.
  • Such a control pattern is referred to as a “driving voltage fixed type” for convenience. Which control pattern is to be selected should be determined in consideration of the type of vehicle and the displacement.
  • the electronic control unit 4 has, for example, a microcomputer (not shown) having a known and well-known configuration, a storage element (not shown) such as a RAM and a ROM, and a fuel injection valve 2-
  • a circuit (not shown) for energizing and driving 1 to 2-n and a circuit (not shown) for energizing and driving the metering valve 6 and the like are configured as main components.
  • various detection signals such as the engine speed, the accelerator opening, the engine coolant temperature, and the fuel temperature are received from the engine. 3 is input to be used for operation control 3 and fuel injection control.
  • the electronic control unit 4 is adapted to read the terminal voltage of the piezo injector that is required in the pressure sensor diagnosis processing in the embodiment of the present invention to be described later.
  • FIG. 7 shows an overall procedure of pressure sensor diagnosis processing in the first configuration example in a subroutine flowchart, and the contents thereof will be described below with reference to FIG.
  • the pressure sensor diagnosis process in the embodiment of the present invention is executed variously for the vehicle operation control in the electronic control unit 4 and is subjected to a subroutine process as one of the control processes.
  • the pressure sensor diagnosis process by the electronic control unit 4 is started, first, whether or not the operation state of the vehicle is an operation state suitable for performing the pressure sensor diagnosis, that is, the operation state of the engine 3 is stabilized. Is determined (see steps S502 to S512 in FIG. 7).
  • the electronic control unit 4 obtains the engine coolant temperature change ⁇ Tc (see step S502 in FIG. 7). That is, based on the engine cooling water temperature input to the electronic control unit 4, the amount of change in the engine cooling water temperature in a predetermined unit time (for example, every minute) is calculated and calculated. Next, it is determined whether or not the water temperature change amount ⁇ Tc acquired by calculation is smaller than the predetermined water temperature change amount K1 (see step S504 in FIG. 7). If it is determined that the water temperature change amount ⁇ Tc is smaller than the predetermined water temperature change amount K1 (YES) In the case), the process by the electronic control unit 4 proceeds to the process of step S506 described below.
  • the electronic control unit 4 causes the engine coolant temperature change amount not to be smaller than the predetermined water temperature change amount K1, in other words, the engine coolant water temperature change amount exceeds the predetermined water temperature change amount K1.
  • step S506 the fuel temperature change amount ⁇ Tf is acquired by the electronic control unit 4. That is, based on the fuel temperature input to the electronic control unit 4, the fuel temperature change amount (fuel temperature change amount) ⁇ Tf in a predetermined unit time (for example, one minute interval) is calculated and calculated. Next, it is determined whether or not the calculated fuel temperature change amount ⁇ Tf is smaller than the predetermined fuel temperature change amount K2 (see step S508 in FIG. 7). If it is determined that the calculated fuel temperature change amount ⁇ Tf is smaller than the predetermined fuel temperature change amount K2 (YES) In the case of (1), the processing by the electronic control unit 4 proceeds to the processing of step S510 described below.
  • step S508 the electronic control unit 4 determines that the fuel temperature change amount ⁇ Tf is not smaller than the predetermined fuel temperature change amount K2, in other words, the fuel temperature change amount exceeds the predetermined fuel temperature change amount K2.
  • NO in the case of NO
  • the series of processing is terminated assuming that the operation state of the vehicle is not suitable for performing pressure sensor diagnosis, and the process returns to the main routine (not shown).
  • step S510 an elapsed time (energization time) t from the start of energization drive to the piezo injector is acquired, and then whether or not the energization time t exceeds a predetermined energization time Ts is determined. (See step S512 in FIG. 7).
  • the energization time which is the elapsed time from the start of energization drive, is acquired by a known and known time measuring program executed inside the electronic control unit 4.
  • the predetermined energization time Ts is determined from the viewpoint of securing a sufficient energization time for obtaining a desired terminal voltage (described later in detail) of a piezo injector in a diagnosis process (step S600 in FIG. 7) described later.
  • An appropriate value should be set for each apparatus based on tests, simulations, and the like.
  • Ts is set to about 300 ⁇ s.
  • step S512 when it is determined that the energization time t is not longer than the predetermined energization time Ts (in the case of NO), the series of processes is terminated, assuming that the current state is not suitable for performing the diagnostic process. Then, the process returns to the main routine (not shown).
  • step S512 when it is determined that the energization time t is longer than the predetermined energization time Ts (in the case of YES), the electronic control unit 4 performs the process as being in a state suitable for the diagnosis process.
  • the process proceeds to step S600, where the diagnosis process described below is executed, and thereafter, the process once returns to the main routine (not shown).
  • FIG. 8 shows a specific processing procedure of the diagnostic processing in a subroutine flowchart.
  • the specific processing procedure will be described with reference to FIG.
  • the series of processing shown in FIG. 8 is executed for each of the fuel injection valves 2-1 to 2-n. That is, the series of processing shown in FIG. 8 is executed for each fuel injection valve 2-1 to 2-n in a predetermined order.
  • the result of the diagnosis processing in each of the fuel injection valves 2-1 to 2-n is comprehensively determined, and finally This is because it is determined whether or not the pressure sensor 11 is abnormal.
  • the value of the first peak value V1 (first actually measured voltage) generated after the energization driving of the piezo injector is started is read by the electronic control unit 4 (FIG. 8). (See step S602).
  • the basic principle of the diagnostic processing in the embodiment of the present invention will be described with reference to FIG. First, as a result of earnest research on the relationship between the operation of the piezo injector and the rail pressure, the inventor of the present application has caused an abnormality in the output signal due to a failure of the pressure sensor 11 or the like.
  • FIG. 11 shows an example of the time change of the terminal voltage when the piezo injector is energized.
  • the horizontal axis represents the elapsed time from the start of energization, and the ordinate represents the terminal voltage of the piezo injector. .
  • the characteristic line represented by a solid line in the figure shows an example of the time change of the terminal voltage during energization driving of the piezo injector at a certain rail pressure when the pressure sensor 11 is normal and the entire vehicle operation is also normal. Is.
  • the terminal voltage of a piezo injector generally shows a so-called pulsation state that changes up and down after the start of energization.
  • the terminal voltage rises at a relatively fast rate of change and reaches a first peak at a certain voltage (Fig. 11 (voltage value at time t1) at 11 and immediately after that, the voltage starts decreasing and decreases with a time change substantially the same as the rising.
  • Fig. 11 voltage value at time t1
  • the initial peak voltage immediately after the start of energization is referred to as “charging start peak voltage” for convenience.
  • the voltage drops to a certain voltage, the voltage starts to rise again, and reaches a second peak at a certain voltage lower than the first peak voltage described above. Thereafter, the voltage is repeatedly moved up and down in the same manner.
  • energization is terminated and the piezo injector is discharged, so that the terminal voltage rapidly decreases (see FIG. 11).
  • the terminal voltage of the piezo injector at time t2 is referred to as “discharge start voltage” for convenience.
  • the drive control of the piezo injector is such that the voltage reaches a peak at a preset voltage at the above-described time t1, and the voltage at the time t2 when the energization ends is a voltage set in advance as a target.
  • the size of the energizing current of the piezo injector, the energizing time, etc. are set and driven. Therefore, when the entire vehicle apparatus is in a normal operation state, the voltage V1 at time t1 and the voltage V2 at time t2 are voltages set in advance or voltages within a predetermined deviation range.
  • the change in the terminal voltage of the piezo injector is the difference between the actual rail pressure and the detected rail pressure by the pressure sensor 11. It changes as described below depending on the magnitude relationship. That is, first, when the rail pressure detected by the pressure sensor 11 is lower than the actual rail pressure, the change in the terminal voltage of the piezo injector is, for example, as shown by a characteristic line represented by a one-dot chain line in FIG. The voltage V1 at the time t1 is shifted to a voltage higher than that at the normal time, and the shift amount corresponds to the difference from the original rail pressure, while the voltage V2 at the time t2 is the normal time (in FIG. 11). (See the characteristic line for solid lines).
  • the change in the terminal voltage of the piezo injector is, for example, like a characteristic line represented by a two-dot chain line in FIG.
  • the voltage V1 at the time t1 is substantially the same value as that at the normal time, while the voltage V2 at the time t2 is shifted to a voltage higher than that at the normal time (see the solid characteristic line in FIG. 11). Corresponds to the difference from the original rail pressure.
  • the rail pressure detected by the pressure sensor 11 is greater than the actual rail pressure. It can be determined that the state is abnormal. Further, when the difference between the actual voltage V1 at time t1 and the actual voltage V2 at time t2 is larger than the predetermined threshold value ⁇ , the rail pressure detected by the pressure sensor 11 is abnormally lower than the actual rail pressure. It can be judged that it is in a state.
  • the first measured voltage V1 read in step S602 is the voltage at the time t1 described in FIG.
  • the time t2 described in FIG. 11, that is, in other words, the voltage (second measured voltage) V2 at the end of energization of the piezo injector is read by the electronic control unit 4 and is stored in the electronic control unit 4. It is temporarily stored in a predetermined storage area (not shown) (see step S604 in FIG. 8).
  • the target second voltage V2T at time t2 (see FIG. 11) stored in advance in a predetermined storage area (not shown) in the electronic control unit 4 is read (see step S606 in FIG. 8).
  • the target second voltage V2T is determined in advance as described above with reference to FIG. 11, and is stored in a predetermined storage area (not shown) of the electronic control unit 4.
  • the electronic control unit 4 determines whether or not the difference between the second actually measured voltage and the target second voltage, V2 ⁇ V2T exceeds a predetermined threshold ⁇ (see step S608 in FIG. 8). If the electronic control unit 4 determines that V2 ⁇ V2T> ⁇ (YES), it is determined that the pressure sensor 11 is abnormal (see step S612 in FIG. 8), and a main routine (not shown) It will return to once.
  • step S608 if it is determined in step S608 that V2 ⁇ V2T> ⁇ is not satisfied (in the case of NO), the difference between the first actual measurement voltage V1 and the second actual measurement voltage V2 acquired previously is a predetermined threshold value ⁇ Is determined by the electronic control unit 4 (see step S610 in FIG. 8). If it is determined that V1-V2> ⁇ is satisfied (in the case of YES), it is determined that the pressure sensor 11 is abnormal (see step S612 in FIG. 8), and the process once returns to the main routine (not shown). .
  • the determination of the sensor abnormality in step S612 is a result of executing the above-described series of diagnostic processing for one of the fuel injection valves 2-1 to 2-n.
  • processing such as abnormality notification.
  • the final diagnosis process will be described with reference to the subroutine flowchart shown in FIG.
  • the series of processing shown in FIG. 8 is performed for each of the fuel injection valves 2-1 to 2-n, in other words, for each cylinder of the engine 3. Even if it is determined that the sensor is abnormal due to the diagnosis process in the one fuel injection valve, the corresponding process such as abnormality notification is not performed immediately, but as described below. The necessity of abnormality notification is selected by the final diagnosis process.
  • the processing is started by the electronic control unit 4, first, the previous fuel injectors 2-1 to 2-n stored in a predetermined storage area (not shown) of the electronic control unit 4 are stored.
  • the results J1 to Jn of the diagnosis process shown in FIG. 8 are read (see step S612 in FIG. 8 and step S802 in FIG. 9).
  • the number of diagnosed sensor abnormalities see step S612 in FIG. 8 is counted by the electronic control unit 4, and the count value of the number of abnormal diagnoses. N is determined (see step S804 in FIG. 9).
  • step S806 it is determined by the electronic control unit 4 whether or not the count value N is greater than the predetermined reference count value Ns (see step S806 in FIG. 9), and the count value N is not greater than the predetermined reference count value Ns. Is determined (NO), the pressure sensor 11 is not abnormal and a series of processes are terminated, and the process returns to a main routine (not shown). On the other hand, if the electronic control unit 4 determines in step S806 that the count value N is greater than the predetermined reference count value Ns (in the case of YES), it is determined that the pressure sensor 11 is abnormal and the electronic control unit 4 will be notified of abnormality (see step S808 in FIG. 9). In addition, although it is suitable for abnormality notification to generate
  • FIG. 12 shows an example of changes in the terminal voltage when the piezo injector is energized, as in FIG. 11, in which the horizontal axis indicates the elapsed time from the start of energization and the vertical axis indicates the piezo injector voltage.
  • a solid characteristic line is an example of a change in the terminal voltage of the piezo injector at a certain rail pressure when the pressure sensor 11 is normal and the entire vehicle apparatus is in a normal operating state.
  • a characteristic line indicated by a two-dot chain line indicates that a terminal pressure of the piezo injector is obtained when the pressure sensor 11 outputs a rail pressure higher than the original rail pressure due to an abnormality in the output of the pressure sensor 11 or the like.
  • An example in which the voltage change is displaced in the direction in which the voltage increases with respect to the original change, that is, the characteristic line of the solid line is shown. Note that the times t1 and t2 in FIG. 12 are the same as the times t1 and t2 described above with reference to FIG.
  • the change in the terminal voltage of the piezo injector shifts from the solid characteristic line indicating the original change.
  • the solid characteristic line indicating the original change.
  • the drive voltage to the piezo injector indicated by the electronic control unit 4 deviates from the original value. It may be like the characteristic line of the dotted line.
  • the two-dot chain characteristic line in FIG. 12 is an example of a change in the terminal voltage of the piezo injector when the rail pressure detected by the pressure sensor 11 is higher than the original correct rail pressure.
  • the driving control of the piezo injector is conventionally performed by correcting the applied voltage of the piezo injector at the time t2 when the energization ends.
  • the target second voltage V2T which is the target voltage at time t2 (see FIG. 11) is determined according to the rail pressure. It has been.
  • the terminal voltage of the piezo injector at time t2 is higher than the target second voltage VT, an applied voltage that is lower than the previous applied voltage by the correction amount U2 is applied to the piezo injector at the next driving of the piezo injector.
  • the terminal voltage of the piezo injector may deviate from the target second voltage VT to some extent, but the correction amount U2
  • the pressure sensor 11 is abnormal or faulty.
  • the pressure sensor 11 is diagnosed based on the magnitude of the correction amount U2.
  • the average value (hereinafter referred to as “average correction amount U2av”) is calculated by the electronic control unit 4 (see step S704 in FIG. 10).
  • the absolute value K of the difference between the average correction amount U2av obtained as described above and the latest correction amount U2 at this time is calculated by the electronic control unit 4 (see step S706 in FIG. 8).
  • step S708 whether or not the absolute value K exceeds the predetermined threshold value Ks is determined by the electronic control unit 4 (see step S708 in FIG. 10), and when it is determined that the absolute value K does not exceed the predetermined threshold value Ks (in the case of NO). Will temporarily return to the main routine (not shown), assuming that there is no abnormality in the pressure sensor 11.
  • step S708 when it is determined in step S708 that the absolute value K exceeds the predetermined threshold Ks (in the case of YES), it is determined that the pressure sensor 11 is abnormal (sensor abnormality) (see step S710 in FIG. 10). ), The series of processes is terminated, and the process in the electronic control unit 4 once returns to the main routine (not shown).
  • step S710 since the determination of sensor abnormality in step S710 is a result of executing the above-described series of diagnostic processing on one of the fuel injectors 2-1 to 2-n, this one sensor From the point of view of careful diagnosis, rather than immediately performing a response process such as abnormality notification only by determining that there is an abnormality, as described above with reference to FIG. 9, in the diagnosis process for a plurality of fuel injection valves When it is determined that the sensor is abnormal, it is preferable to perform processing such as abnormality notification. A detailed description of the final diagnosis process shown in FIG. 9 will not be repeated here.
  • the change in the terminal voltage of the piezo injector is used for the failure diagnosis of the pressure sensor, it can be applied to the diagnosis of the pressure sensor in the common rail fuel injection device using the piezo injector.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Abstract

L'invention porte sur un procédé de diagnostic de capteur de pression permettant le diagnostic de la présence/absence d'anomalie avec une constitution simple mais sans prévoir aucun circuit dédié pour diagnostiquer l'action d'un capteur de pression. Une unité de commande électronique (4) alimente des soupapes d'injection de carburant (2-1 à 2-n), agissant comme un injecteur piézo, avec un courant d'attaque prédéterminé (Is) pendant un temps d'attaque prédéterminé (ET). Dans l'oscillation de la tension terminale de l'injecteur piézo qui se produit pendant la période d'alimentation, la différence de potentiel entre une première tension de pic qui se produit tout d'abord après l'alimentation en puissance et une seconde tension de pic qui se produit ensuite est déterminée. Une pression de rampe standard intrinsèque à la différence de potentiel est déterminée en fonction d'une corrélation prédéterminée entre la différence de potentiel de la première tension de pic et de la seconde tension de pic et la pression de rampe standard. Il est déterminé que le capteur de pression (11) présente une anomalie si la différence par rapport à une pression de rampe détectée, obtenue par un capteur de pression (11), est supérieure à une valeur de seuil prédéterminée.
PCT/JP2009/065035 2008-10-28 2009-08-28 Procédé de diagnostic de capteur de pression et dispositif de commande d'injection de combustible de type à rampe commune WO2010050289A1 (fr)

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KR101593431B1 (ko) * 2014-08-01 2016-02-19 현대오트론 주식회사 지디아이 차량의 고압 연료 센서 고착 진단 방법
GB2543473A (en) * 2015-06-03 2017-04-26 Gm Global Tech Operations Llc Method of diagnosing a fuel rail pressure sensor
US9926876B2 (en) 2015-06-03 2018-03-27 GM Global Technology Operations LLC Method of diagnosing a fuel rail pressure sensor
KR101862910B1 (ko) 2015-12-30 2018-07-05 주식회사 현대케피코 연료압력센서 진단 장치 및 방법

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