JP2014152740A - Fuel injection control device and fuel injection control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control valve opening time of a fuel injection valve or the fuel injection amount from the fuel injection valve by improving detection accuracy of vibration generated when the fuel injection valve is opened/closed.SOLUTION: In a fuel injection control device 80, an actual valve opening time extraction part 88 extracts actual valve opening time ΔT of fuel injection valves 10A-10D on the basis of sensor signals Ss1-Ss4 from cylinder internal pressure sensors 20A-20D installed at tips of the fuel injection valves 10A-10D. A correction processing part 96 corrects valve opening time of the fuel injection valves 10A-10D or the fuel injection amounts injected from the fuel injection valves 10A-10D on the basis of a valve opening time initial value T0 and the actual valve opening time ΔT.

Description

  The present invention relates to a fuel injection control device and a fuel injection control method for controlling a fuel injection valve that directly injects fuel into a combustion chamber in a cylinder of an internal combustion engine.

  Conventionally, a knock sensor is provided in a direct fuel injection internal combustion engine having a fuel injection valve that directly injects fuel into a combustion chamber in a cylinder, and the vibration state of the internal combustion engine detected by the knock sensor (for example, the fuel injection valve Patent Document 1 discloses that the valve opening time of the fuel injection valve is adjusted based on an output signal corresponding to vibration at the time of opening and closing.

Japanese Patent No. 3242596

  The knock sensor is attached to the engine body (for example, the side of the cylinder block) in order to detect mechanical vibration generated in the internal combustion engine.

  Therefore, when one knock sensor is attached to a multi-cylinder engine, the distance between the knock sensor and each cylinder differs depending on the attachment position of the knock sensor. As a result, a time difference occurs in the vibration transmitted from each cylinder to the knock sensor. Therefore, when adjusting the valve opening time based on the output signal from the knock sensor, the delay time of the output time must be considered for each cylinder.

  In addition, when detecting vibration from any cylinder, the knock sensor detects vibration caused by combustion in other cylinders, vibration of the intake valve and exhaust valve in addition to vibration from the cylinder, and outputs an output signal. May also be output. Since these vibrations are external noises other than vibrations from an arbitrary cylinder for the knock sensor, the detection accuracy of the knock sensor decreases due to detection errors caused by these vibrations. As a result, the valve opening time cannot be accurately controlled.

  In general, since the valve opening time of the fuel injection valve and the fuel injection amount injected from the fuel injection valve are in a proportional relationship, the fuel injection amount is controlled based on the output signal from the knock sensor. However, similar problems are expected to arise.

  The present invention has been made in consideration of the above-described various problems, and improves the detection accuracy of vibrations when the fuel injection valve is opened and closed. It is an object of the present invention to provide a fuel injection control device and a fuel injection control method capable of accurately controlling the fuel injection amount.

  In order to achieve the above object, in the present invention, in-cylinder pressure detecting means for detecting an in-cylinder pressure in a cylinder and outputting an output signal corresponding to the detected in-cylinder pressure is provided near the tip of the fuel injection valve. ing.

  In this case, the fuel injection control device according to the present invention detects an actual valve opening time that is an actual valve opening time of the fuel injection valve based on the output signal from the in-cylinder pressure detecting means. Based on the detection means, a valve opening time initial value that is an initial value of the valve opening time of the fuel injection valve obtained in advance, and the actual valve opening time, or the valve opening time of the fuel injection valve, or Correction means for correcting the fuel injection amount injected from the fuel injection valve.

  The fuel injection control method according to the present invention includes a step of detecting the actual valve opening time based on the output signal output from the in-cylinder pressure detecting means, the valve opening time initial value, and the actual valve opening. And a step of correcting a valve opening time of the fuel injection valve or a fuel injection amount injected from the fuel injection valve based on the time.

  According to these inventions, since the in-cylinder pressure detecting means is provided in the vicinity of the tip of the fuel injection valve, compared to Patent Document 1, the cylinder pressure detecting means is provided for each cylinder according to the mounting position of the in-cylinder pressure detecting means. It is possible to avoid occurrence of a delay time in the detected output signal. Accordingly, when the valve opening time or the fuel injection amount is controlled based on the output signal, it is not necessary to consider the delay time of the output time.

  In addition, the output signal corresponding to each cylinder is less susceptible to the influence of other vibration sources (for example, vibration due to combustion in other cylinders, vibration of intake valves and exhaust valves). Thereby, the detection accuracy of the in-cylinder pressure detecting means can be improved.

  Thus, in the present invention, by providing the in-cylinder pressure detection means in the vicinity of the tip of the fuel injection valve, the detection accuracy of vibration at the time of opening and closing the fuel injection valve is improved. If the valve opening time or the fuel injection amount is corrected using the output signal, the valve opening time or the fuel injection amount can be accurately controlled.

  Here, the configuration of the present invention when the correction means corrects the valve opening time and the configuration of the present invention when the fuel injection amount is corrected will be described.

  First, in the case where the correction unit corrects the valve opening time, the correction unit is configured such that when the absolute value of the rate of change of the actual valve opening time with respect to the valve opening time initial value is equal to or greater than a predetermined time threshold value, It is an actual valve opening time correction means for correcting the valve opening time. Thereby, the valve opening time can be corrected efficiently.

  In this case, it is preferable that the actual valve opening time correcting means corrects the actual valve opening time by the correction time, using a deviation amount of the actual valve opening time with respect to the initial valve opening time as a correction time. Accordingly, even if the actual valve opening time is deviated from the initial valve opening time value, the fuel injection valve is accurately controlled by correcting the initial valve opening time value using the correction time. It becomes possible.

  On the other hand, in the case where the correction means corrects the fuel injection amount, the fuel injection control device determines the fuel actually injected from the fuel injection valve during the actual valve opening time based on the actual valve opening time. Fuel injection amount calculation means for calculating the injection amount as the estimated fuel injection amount is further provided. In this case, the correction means has an absolute value of a rate of change of the estimated fuel injection amount with respect to an injection amount initial value that is an initial value of the fuel injection amount corresponding to the valve opening time initial value equal to or greater than a predetermined injection amount threshold value. In this case, the fuel injection amount correction means corrects the fuel injection amount injected from the fuel injection valve. Even in this case, the fuel injection amount can be corrected efficiently.

  In this case, it is preferable that the fuel injection amount correcting means corrects the estimated fuel injection amount with the corrected injection amount, using a deviation amount of the estimated fuel injection amount with respect to the initial injection amount as a correction injection amount. Thus, even if the estimated fuel injection amount deviates from the initial injection amount value, the fuel injection valve is accurately controlled by correcting the fuel injection valve to the initial injection amount value using the corrected injection amount. Is possible.

  In the above invention, the actual valve opening time detecting means extracts a waveform indicating the valve opening operation and the valve closing operation of the fuel injector included in the output signal, and the actual valve opening time is extracted from the extracted waveform. It is preferable to detect time. Thereby, the actual valve opening time can be detected easily and accurately.

  According to the present invention, the following effects can be obtained.

  That is, by providing the in-cylinder pressure detecting means in the vicinity of the tip of the fuel injection valve, the vibration detection accuracy when the fuel injection valve is opened and closed is improved. Alternatively, if the fuel injection amount is corrected, the valve opening time or the fuel injection amount can be accurately controlled.

It is the front view which fractured | ruptured and illustrated about the fuel injection valve controlled by the fuel-injection control apparatus which concerns on this embodiment. FIG. 2 is a block diagram of the fuel injection control device. 3A and 3B are flowcharts showing a correction process of the valve opening time or the fuel injection amount by the fuel injection control device of FIG. FIG. 4A is a timing chart showing a waveform of a sensor signal output from the in-cylinder pressure sensor, and FIG. 4B is a timing chart showing an enlarged part of FIG. 4A.

  The fuel injection control apparatus according to the present invention will be described in detail below with reference to the accompanying drawings by giving preferred embodiments in relation to the fuel injection control method.

[Configuration of fuel injection valve]
Prior to the description of the fuel injection control apparatus according to the present embodiment, the configuration of the fuel injection valve 10 controlled by the fuel injection control apparatus will be described with reference to FIG.

  The fuel injection valve 10 is applied to, for example, a direct fuel injection internal combustion engine, and is suitable as a fuel injection valve that directly injects fuel into a combustion chamber in a cylinder.

  That is, the fuel injection valve 10 is connected to the housing 12, the solenoid part 14 provided at the front end of the housing 12, the fuel injection part 16 provided at the front end of the solenoid part 14, and the base end of the housing 12. The fuel supply unit 18 that supplies fuel to the fuel cell 16, the in-cylinder pressure sensor 20 (in-cylinder pressure detection means) mounted at the tip of the fuel injection unit 16, the terminal 22 provided in the housing 12 and the in-cylinder pressure sensor 20 And a signal transmission unit 24 to be connected to each other. In the present embodiment, the fuel supply unit 18 side of the fuel injection valve 10 is a base end side (arrow A direction), and the fuel injection unit 16 side is a front end side (arrow B direction).

  The housing 12 includes a main body portion 26 and a coupler 28 that protrudes laterally from the base end of the main body portion 26. In this case, the fuel supply unit 18 is inserted into the main body 26. The fuel supply unit 18 includes, for example, a supply passage (not shown) for supplying fuel, and supplies fuel supplied from the outside through a fuel pipe to the fuel injection unit 16 from the supply passage. A harness connector (not shown) is detachably attached to the coupler 28.

  The solenoid unit 14 includes a cylindrical coil housing 30, a bobbin 32 housed inside the coil housing 30, and a coil 34 wound around the bobbin 32. The base end side of the bobbin 32 is formed as a terminal support portion 36 that holds the tip portions of the pair of power supply terminals 22a and 22c and the signal terminal 22b. A movable core 38 is housed inside the solenoid unit 14 and inside the bobbin 32. A needle 40 extending in the direction of arrow A and the direction of arrow B is connected to the movable core 38 through the inside of the solenoid unit 14 and the fuel injection unit 16.

  Here, the power supply terminals 22 a and 22 c are electrically connected to the coil 34. In addition, the base end sides of the power supply terminals 22 a and 22 c and the signal terminal 22 b are exposed to the outside from a recess formed in the coupler 28. When the coupler 28 and the connector of the harness are fitted and the power supply terminals 22a and 22c are energized from the outside via the harness, the connector, and the coupler 28, the coil 34 is excited and magnetic force is generated. Thereby, the movable core 38 can be displaced in the direction of the arrow A inside the bobbin 32 under the exciting action of the coil 34.

  The fuel injection part 16 has a valve housing 42 connected to the tip of the solenoid part 14. The valve housing 42 is formed of, for example, a metal material, and includes a flange portion 44 that closes the tip of the solenoid portion 14 and a cylindrical portion 46 that extends straight from the flange portion 44 in the direction of arrow B.

  An injection port 50 is formed at the tip of the cylindrical portion 46, and the injection port 50 is closed by a spherical valve body 52 attached to the tip of the needle 40. As described above, when the movable core 38 is displaced in the arrow A direction under the excitation action of the coil 34, the needle 40 and the valve body 52 move integrally in the arrow A direction. As a result, the valve body 52 is separated from the injection port 50, the fuel injection valve 10 is shifted from the closed state to the open state, and fuel can be injected from the injection port 50 into the combustion chamber at a predetermined pressure.

  A cylindrical in-cylinder pressure sensor 20 is press-fitted and fitted to the outer peripheral side of the tip of the cylinder portion 46. The in-cylinder pressure sensor 20 includes, for example, a piezoelectric element (not shown) therein, and a connection terminal 48 is connected to the piezoelectric element. Therefore, the in-cylinder pressure sensor 20 detects the pressure (in-cylinder pressure) of the combustion chamber in the cylinder using a piezoelectric sensor, and a detection signal corresponding to the detected in-cylinder pressure is provided as a sensor signal (output signal) via the connection terminal 48. Output.

  The signal transmission unit 24 is provided on the outer peripheral side of the valve housing 42, and is accommodated in the first signal transmission member 54 connected to the connection terminal 48, the coil housing 30, and the first signal transmission member 54 and the signal terminal 22b. And a second signal transmission member 56 to be connected.

  The first signal transmission member 54 is provided on the outer peripheral side of the cylindrical portion 46, and is provided with an insulator 58 made of a resin material such as a heat-resistant resin, and a member that is provided inside the insulator 58 and can be energized such as a plating layer. The first conductive layer 60 is made of. A cover member 62 that covers the insulator 58 is attached to the outer peripheral side of the insulator 58.

  The second signal transmission member 56 is formed of, for example, a resin material and has a plate shape having a predetermined length along the arrow A direction and the arrow B direction. A second conductive layer 72 made of an energizable member such as a plating layer is formed inside. A first connection part 74 that electrically connects the first conductive layer 60 and the second conductive layer 72 is formed at the tip of the second conductive layer 72. A second connection portion 76 that electrically connects the second conductive layer 72 and the signal terminal 22 b is formed at the base end of the second conductive layer 72.

  Thereby, the in-cylinder pressure sensor 20 is connected to the in-cylinder pressure via the connection terminal 48, the first conductive layer 60, the first connection portion 74, the second conductive layer 72, the second connection portion 76, the signal terminal 22b, the connector, and the harness. A sensor signal corresponding to the signal can be output to the outside.

[Configuration of this embodiment]
Next, the fuel injection control device 80 according to this embodiment for controlling the fuel injection valve 10 will be described with reference to FIG.

  In FIG. 2, as an example, an engine 82 that is an internal combustion engine has four cylinders 84A to 84D (indicated by circles with “# 1” to “# 4” in FIG. 2), and each cylinder 84A to 84D has On the other hand, the fuel injection valves 10A to 10D (indicated by blocks with “CPS INJ1” to “CPS INJ4” in FIG. 2) provided with in-cylinder pressure sensors 20A to 20D are respectively illustrated. is there.

  The fuel injection valves 10A to 10D have the same configuration as the fuel injection valve 10 shown in FIG. 1, and the combustion chambers in the cylinders 84A to 84D are in an open state in which the valve body 52 is separated from the injection port 50. Each fuel is injected. The in-cylinder pressure sensors 20A to 20D have the same configuration as the in-cylinder pressure sensor 20, respectively detect the in-cylinder pressures of the combustion chambers in the cylinders 84A to 84D, and output sensor signals Ss1 to Ss4 corresponding to the detected in-cylinder pressures. To do. Therefore, detailed description of the fuel injection valves 10A to 10D and the cylinder pressure sensors 20A to 20D is omitted here.

  In the fuel injection control device 80, an ECU (Engine Control Unit) 86 is an ECU of a vehicle on which the engine 82 is mounted, and each of the fuel injection valves 10A to 10D and the in-cylinder pressure sensors 20A to 20D via the harness and the connector. And are electrically connected.

  In this case, the ECU 86 acquires sensor signals Ss1 to Ss4 output from the in-cylinder pressure sensors 20A to 20D, respectively. Based on the sensor signals Ss1 to Ss4, the ECU 86 opens a valve opening time appropriate for the fuel injection valves 10A to 10D (time when the valve body 52 is separated from the injection port 50) or a fuel injection amount (valve opening). The amount of fuel injected into the combustion chamber in time is set, and drive signals Sd1 to Sd4 corresponding to the set valve opening time or fuel injection amount are supplied to the fuel injection valves 10A to 10D, respectively.

  As a result, the coils 34 of the fuel injection valves 10A to 10D are excited by the supplied drive signals Sd1 to Sd4, respectively, and the movable core 38, the needle 40, and the valve body 52 are integrally displaced in the arrow A direction. As a result, the valve body 52 is separated from the injection ports 50 of the fuel injection valves 10A to 10D, and the fuel injection valves 10A to 10D shift from the closed state to the open state. Accordingly, each of the fuel injection valves 10A to 10D can inject fuel from the injection port 50 into the combustion chambers of the cylinders 84A to 84D for a predetermined valve opening time.

  On the other hand, when the supply of the drive signals Sd1 to Sd4 is stopped after the valve opening time has elapsed, the exciting action of the coil 34 is stopped, and the movable core 38, the needle 40 and the valve body 52 are integrally displaced in the direction of arrow B. Then, the valve body 52 closes the injection port 50. As a result, the fuel injection valves 10A to 10D shift from the open state to the closed state, and fuel injection from the fuel injection valves 10A to 10D stops.

  In order to exhibit such a function, the ECU 86 includes an actual valve opening time extraction unit 88 (actual valve opening time detection unit), a fuel injection amount calculation unit 90 (fuel injection amount calculation unit), a change amount calculation unit 92, and a determination processing unit. 94, a correction processing unit 96 (correction unit, actual valve opening time correction unit, fuel injection amount correction unit), a drive signal generation unit 98, and a storage unit 100.

  The actual valve opening time extraction unit 88 is based on the sensor signals Ss1 to Ss4 input from the in-cylinder pressure sensors 20A to 20D to the ECU 86, and the actual valve opening time ΔT1 that is the actual valve opening time of each of the fuel injection valves 10A to 10D. Extract ~ ΔT4.

  The fuel injection amount calculation unit 90 is actually injected from the fuel injection valves 10A to 10D during the actual valve opening times ΔT1 to ΔT4 based on the actual valve opening times ΔT1 to ΔT4 extracted by the actual valve opening time extraction unit 88. Fuel injection amounts Q1 to Q4 (estimated fuel injection amount) are calculated.

  In general, the valve opening time of the fuel injection valves 10A to 10D and the fuel injection amount from the fuel injection valves 10A to 10D are in a proportional relationship. Therefore, for example, a first table (not shown) indicating the proportional relationship between the valve opening time and the fuel injection amount is stored in the storage unit 100, and the fuel injection amount calculation unit 90 refers to the first table and performs the actual opening. The estimated fuel injection amounts Q1 to Q4 corresponding to the valve times ΔT1 to ΔT4 may be estimated.

  The change amount calculation unit 92 calculates a change rate (opening time change rate) of the actual valve opening times ΔT1 to ΔT4 with respect to the valve opening time initial value T0 indicating a desired valve opening time obtained in advance. A change rate (injection amount change rate) of the estimated fuel injection amounts Q1 to Q4 with respect to an injection amount initial value Q0 indicating a desired fuel injection amount corresponding to the valve time initial value T0 is calculated.

  The initial valve opening time T0 is the ideal value of the fuel injection valves 10A to 10D corresponding to the drive signals Sd1 to Sd4 when the drive signals Sd1 to Sd4 are supplied to the fuel injection valves 10A to 10D in which no failure or the like has occurred. This is the typical valve opening time. Therefore, for example, a second table (not shown) indicating an ideal relationship between the drive signals Sd1 to Sd4 and the valve opening time is stored in the storage unit 100, and the change amount calculation unit 92 refers to the second table. The valve opening time corresponding to the drive signals Sd1 to Sd4 actually supplied from the ECU 86 to the fuel injection valves 10A to 10D is specified, and the specified valve opening time is determined as the valve opening time initial value T0.

  In addition, the injection amount initial value Q0 is determined from the fuel injection valves 10A to 10D corresponding to the drive signals Sd1 to Sd4 when the drive signals Sd1 to Sd4 are supplied to the fuel injection valves 10A to 10D in which no failure or the like has occurred. The ideal fuel injection amount. As described above, since the valve opening time and the fuel injection amount are in a proportional relationship, the injection amount initial value Q0 is also the fuel injection amount corresponding to the valve opening time initial value T0.

  Therefore, for example, a third table (not shown) indicating an ideal relationship between the drive signals Sd1 to Sd4 and the fuel injection amount is stored in the storage unit 100, and the change amount calculation unit 92 refers to the third table. The fuel injection amount corresponding to the drive signals Sd1 to Sd4 actually supplied from the ECU 86 to the fuel injection valves 10A to 10D is specified, and the specified fuel injection amount is determined as the injection amount initial value Q0.

  Alternatively, the first table and the second table are stored in the storage unit 100, and the change amount calculation unit 92 refers to the second table, and the drive signal actually supplied from the ECU 86 to the fuel injection valves 10A to 10D. The valve opening time corresponding to Sd1 to Sd4 is obtained, then, referring to the first table, the fuel injection amount corresponding to the obtained valve opening time is specified, and the specified fuel injection amount is set as the injection amount initial value Q0. You may decide.

  The determination processing unit 94 determines whether or not the absolute value of the valve opening time change rate or the injection amount change rate calculated by the change amount calculating unit 92 is equal to or greater than a predetermined threshold value X (time threshold value, injection amount threshold value). .

  When the determination processing unit 94 gives a positive determination result (the absolute value of the valve opening time change rate or the injection amount change rate is equal to or greater than the threshold value X), the correction processing unit 96 performs actual valve opening with respect to the valve opening time initial value T0. It is determined that the deviation amount of the times ΔT1 to ΔT4 is large, and the actual valve opening times ΔT1 to ΔT4 are corrected so as to become the valve opening time initial value T0, or the estimated fuel injection amounts Q1 to Q1 with respect to the injection amount initial value Q0. It is determined that the deviation amount of Q4 is large, and the estimated fuel injection amounts Q1 to Q4 are corrected to become the injection amount initial value Q0.

  When the determination processing unit 94 has a negative determination result (the absolute value of the valve opening time change rate or the injection amount change rate is less than the threshold value X), the correction processing unit 96 performs the actual opening with respect to the valve opening time initial value T0. It is determined that the deviation amount of the valve times ΔT1 to ΔT4 is small, or the deviation amount of the estimated fuel injection amounts Q1 to Q4 with respect to the injection amount initial value Q0 is small, and the actual opening time ΔT1 to ΔT4 or the estimated fuel injection amount Q1 to Q1. The correction process for Q4 is not performed.

  In addition, the determination processing unit 94 compares two threshold values X when comparing the valve opening time change rate with the threshold value X (time threshold value) and when comparing the injection amount change rate with the threshold value X (injection amount threshold value). May be preset to the same value, or may be preset to different values.

  When the correction processing is performed by the correction processing unit 96, the drive signal generating unit 98 performs the actual valve opening times ΔT1 to ΔT4 (valid opening time initial value T0) after correction or the estimated fuel injection amounts Q1 to Q4 (injection). Drive signals Sd1 to Sd4 corresponding to the initial quantity Q0) are generated. In addition, when the correction processing is not performed by the correction processing unit 96, the drive signal generation unit 98 performs the actual valve opening times ΔT1 to ΔT4 extracted by the actual valve opening time extraction unit 88 or the fuel injection amount calculation unit 90. Drive signals Sd1 to Sd4 corresponding to the estimated fuel injection amounts Q1 to Q4 calculated in step 1 are generated.

  The storage unit 100 stores predetermined information including the first to third tables described above.

[Operation of this embodiment]
The fuel injection control device 80 according to the present embodiment is configured as described above. Next, the operation (fuel injection control method) will be described with reference to FIGS. 3A to 4B. In this description of the operation, it will be described with reference to FIGS. 1 and 2 as necessary.

  Here, as shown in FIG. 3A, when the correction processing of the actual valve opening times ΔT1 to ΔT4 is performed based on the valve opening time change rate (first embodiment), and as shown in FIG. 3B, the injection amount change rate. A case where the correction processing of the estimated fuel injection amounts Q1 to Q4 is performed based on the above (second embodiment) will be described.

  First, the operation of the first embodiment of FIG. 3A will be described.

  In step S1 of FIG. 3A, the in-cylinder pressure sensors 20A to 20D detect the in-cylinder pressure in the fuel chamber, and output sensor signals Ss1 to Ss4 corresponding to the detected in-cylinder pressure to the ECU 86.

  In step S2, the actual valve opening time extraction unit 88 of the ECU 86 extracts the actual valve opening times ΔT1 to ΔT4 from the input sensor signals Ss1 to Ss4.

  FIG. 4A is a timing chart showing an example of the in-cylinder pressure waveform corresponding to the sensor signals Ss1 to Ss4, and FIG. 4B is a timing chart illustrating a part of the waveform enlarged.

  4A and 4B, the horizontal axis indicates the crank angle of a crankshaft (not shown) and corresponds to the passage of time. In this case, the first peak of the in-cylinder pressure P1 is generated at the crank angle corresponding to the time point T1, and the second peak of the in-cylinder pressure P2 is generated at the crank angle (a corresponding time point T2) after the predetermined angle from the crank angle. It has occurred.

  The first peak in-cylinder pressure P1 is the in-cylinder pressure detected by the vibration generated when the fuel injection valves 10A to 10D are opened (time point T1) being transmitted to the in-cylinder pressure sensors 20A to 20D. The second peak in-cylinder pressure P2 is the in-cylinder pressure detected by the vibration generated when the fuel injection valves 10A to 10D are closed (time point T2) being transmitted to the in-cylinder pressure sensors 20A to 20D. Therefore, ΔT, which is a time interval corresponding to the angle difference between the crank angle corresponding to the time point T1 and the crank angle corresponding to the time point T2, is the actual valve opening time.

  Accordingly, in step S2, the actual valve opening time extraction unit 88 uses the crank angle indicating the valve opening time (time T1) and the crank angle indicating the valve closing time (time T2) for the waveforms of the sensor signals Ss1 to Ss4, respectively. And the time corresponding to the detected angle difference between the two crank angles is extracted as the actual valve opening time ΔT (ΔT1 to ΔT4).

  In FIG. 4A and FIG. 4B, the horizontal axis is represented by the crank angle, but for convenience of explanation, the time points T1, T2 and the actual valve opening time ΔT are appended in parentheses. In step S2, since the actual valve opening time ΔT may be extracted, it is sufficient that at least the two crank angles can be detected. Therefore, in step S2, the actual valve opening time extraction unit 88 regards at least the range from immediately before the crank angle corresponding to the time point T1 to immediately after the crank angle corresponding to the time point T2 as the fuel injection timing, The time points T1 and T2 may be detected using only the inside as the detection target.

  In step S3, the change amount calculation unit 92 refers to the second table stored in the storage unit 100, and calculates the initial valve opening time value T0 corresponding to the drive signals Sd1 to Sd4 based on the actual valve opening time ΔT. Identify. Then, the change amount calculation unit 92 calculates | ΔT / T0-1 |, which is the absolute value of the valve opening time change rate, using the specified initial valve opening time value T0 and the actual valve opening time ΔT. The determination processing unit 94 determines whether or not the absolute value | ΔT / T0-1 | is equal to or greater than a predetermined threshold value X [%] (whether or not | ΔT / T0-1 | ≧ X).

  When the determination processing unit 94 makes a positive determination (step S3: YES, | ΔT / T0-1 | ≧ X), in the next step S4, the correction processing unit 96 starts from the initial valve opening time value T0. It is determined that the valve opening time ΔT is deviated by X [%] or more, and the actual valve opening time ΔT is corrected so as to become the valve opening time initial value T0.

  Specifically, a deviation amount of the actual valve opening time ΔT with respect to the initial valve opening time value T0 is defined as a correction amount (correction time) Ti. When the actual valve opening time ΔT is shorter than the valve opening time initial value T0, Ti is added to ΔT to correct the valve opening time initial value T0 (ΔT + Ti → ΔT = T0). On the other hand, when the actual valve opening time ΔT is longer than the valve opening time initial value T0, ΔT is subtracted by Ti to correct the valve opening time initial value T0 (ΔT−Ti → ΔT = T0). .

  In step S3, when the determination processing unit 94 makes a negative determination (step S3: NO, | ΔT / T0-1 | <X), the correction processing unit 96 executes the actual value for the initial valve opening time T0. It is determined that the deviation of the valve opening time ΔT is less than X [%], and the correction process for the actual valve opening time ΔT is not executed. As a result, in the fuel injection control device 80, the process of step S1 is executed again, and the next sensor signals Ss1 to Ss4 are acquired.

  Next, the operation of the second embodiment of FIG. 3B will be described.

  In steps S11 and S12 in FIG. 3B, processes similar to those in steps S1 and S2 are performed.

  In the next step S13, the fuel injection amount calculation unit 90 refers to the first table stored in the storage unit 100, and the estimated fuel injection amount corresponding to the actual valve opening time ΔT extracted by the actual valve opening time extraction unit 88. Q (Q1 to Q4) is estimated.

  In step S14, the change amount calculation unit 92 refers to the third table stored in the storage unit 100, and specifies the injection amount initial value Q0 corresponding to the drive signals Sd1 to Sd4 based on the estimated fuel injection amount Q. To do. Then, the change amount calculation unit 92 calculates | Q / Q0-1 |, which is the absolute value of the injection amount change rate, using the specified injection amount initial value Q0 and the estimated fuel injection amount Q. Then, the determination processing unit 94 determines whether or not the absolute value | Q / Q0-1 | is equal to or greater than a predetermined threshold value X [%] (whether or not | Q / Q0-1 | ≧ X). .

  When the determination processing unit 94 makes a positive determination (step S14: YES, | Q / Q0-1 | ≧ X), in the next step S15, the correction processing unit 96 calculates the estimated fuel from the injection amount initial value Q0. It is determined that the injection amount Q is deviated by X [%] or more, and the estimated fuel injection amount Q is corrected so as to become the injection amount initial value Q0.

  Specifically, a deviation amount of the estimated fuel injection amount Q with respect to the injection amount initial value Q0 is set as a correction amount (correction injection amount) Qi. If the estimated fuel injection amount Q is smaller than the injection amount initial value Q0, Qi is added to Q and corrected to the injection amount initial value Q0 (Q + Qi → Q = Q0). On the other hand, when the estimated fuel injection amount Q is larger than the injection amount initial value Q0, Q is subtracted by Qi and corrected to the injection amount initial value Q0 (Q-Qi → Q = Q0).

  In step S14, when the determination processing unit 94 makes a negative determination (step S14: NO, | Q / Q0-1 | <X), the correction processing unit 96 estimates the estimated fuel for the injection amount initial value Q0. It is determined that the deviation of the injection amount Q is less than X [%], and the correction process for the estimated fuel injection amount Q is not executed. As a result, in the fuel injection control device 80, the process of step S11 is executed again, and the next sensor signals Ss1 to Ss4 are acquired.

  When the correction process of the first embodiment or the second embodiment is performed, the drive signal generation unit 98 performs the actual valve opening time ΔT (valve opening time initial value T0) or the estimated fuel injection amount Q after the correction process. Drive signals Sd1 to Sd4 are generated based on (the injection amount initial value Q0). On the other hand, when the correction process of the first embodiment or the second embodiment is not performed, the drive signal generation unit 98 determines the actual valve opening time ΔT extracted in step S2 or the estimated fuel injection amount calculated in step S13. Drive signals Sd1 to Sd4 are generated based on Q. As a result, by supplying drive signals Sd1 to Sd4 from the ECU 86 to the fuel injection valves 10A to 10D, the valve opening time of the fuel injection valves 10A to 10D and the fuel injection from the fuel injection valves 10A to 10D to the combustion chamber Can be accurately controlled.

[Effect of this embodiment]
As described above, according to the present embodiment, the cylinder pressure sensor 20 is provided at the tip of the fuel injection valve 10 (10A to 10D). Depending on the position, it is possible to avoid the occurrence of a delay time in the sensor signals Ss1 to Ss4 detected for each of the cylinders 84A to 84D. Accordingly, when the valve opening time of the fuel injection valve 10 or the fuel injection amount from the fuel injection valve 10 is controlled based on the sensor signals Ss1 to Ss4, it is necessary to consider the delay time of the sensor signals Ss1 to Ss4. Disappears.

  Further, the sensor signals Ss1 to Ss4 corresponding to the respective cylinders 84A to 84D are not easily affected by other vibration sources (for example, vibration caused by combustion of other cylinders, vibrations of the intake valve and the exhaust valve). Thereby, the detection accuracy of the cylinder pressure sensors 20A to 20D can be improved.

  Thus, in this embodiment, since the cylinder pressure sensors 20A to 20D are provided at the tips of the fuel injection valves 10A to 10D, the detection accuracy of vibration at the time of opening and closing the fuel injection valves 10A to 10D is improved. If the valve opening time or the fuel injection amount is corrected using the sensor signals Ss1 to Ss4 from the internal pressure sensors 20A to 20D, the valve opening time or the fuel injection amount can be accurately controlled.

  Further, if | ΔT / T0-1 | ≧ X, the correction processing unit 96 corrects the actual valve opening time ΔT, so that the actual valve opening time ΔT can be corrected efficiently. In this case, the correction processing unit 96 corrects the actual valve opening time ΔT with the correction time Ti by using the deviation amount of the actual valve opening time ΔT with respect to the valve opening time initial value T0 as the correction time Ti. Thus, even if the actual valve opening time ΔT is deviated from the initial valve opening time value T0, the fuel injection valves 10A to 10D can be accurately set by correcting the valve opening time initial value T0 using the correction time Ti. It becomes possible to control.

  Alternatively, the fuel injection amount calculation unit 90 calculates the estimated fuel injection amount Q based on the actual valve opening time ΔT, and the correction processing unit 96 calculates the estimated fuel injection amount if | Q / Q0-1 | ≧ X. Q is corrected. Even in this case, the estimated fuel injection amount Q can be corrected efficiently, and even if the estimated fuel injection amount Q deviates from the injection amount initial value Q0, the injection amount initial value Q0 is obtained using the corrected injection amount Qi. If it correct | amends in this way, it will become possible to control fuel-injection-valve 10A-10D correctly.

  Further, the actual valve opening time extraction unit 88 extracts waveforms (two peaks at time points T1 and T2) indicating the valve opening operation and the valve closing operation of the fuel injection valves 10A to 10D included in the sensor signals Ss1 to Ss4. Since the actual valve opening time ΔT is detected from the extracted waveform, the actual valve opening time ΔT can be easily and accurately detected.

  In the above description, the ECU 86 acquires the sensor signals Ss1 to Ss4 from the four in-cylinder pressure sensors 20A to 20D, and the drive signals Sd1 to Sd4 of the four fuel injection valves 10A to 10D based on the acquired sensor signals Ss1 to Ss4. The case of generating is described. The present embodiment is not limited to this description, and the ECU 86 acquires sensor signals Ss1 to Ss4 from at least one in-cylinder pressure sensor 20A to 20D, and at least 1 based on the acquired sensor signals Ss1 to Ss4. The drive signals Sd1 to Sd4 may be supplied to the fuel injection valves 10A to 10D on which the two in-cylinder pressure sensors 20A to 20D are mounted.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10, 10A-10D ... Fuel injection valve 20, 20A-20D ... In-cylinder pressure sensor 50 ... Injection port 52 ... Valve body 80 ... Fuel injection control apparatus 82 ... Engine 84A-84D ... Cylinder 86 ... ECU
DESCRIPTION OF SYMBOLS 88 ... Actual valve opening time extraction part 90 ... Fuel injection amount calculating part 92 ... Change amount calculation part 94 ... Judgment processing part 96 ... Correction processing part 98 ... Drive signal generation part 100 ... Memory | storage part

Claims (7)

In a fuel injection control device for controlling a fuel injection valve for directly injecting fuel into a combustion chamber in a cylinder of an internal combustion engine,
In-cylinder pressure detection means for detecting an in-cylinder pressure in the cylinder and outputting an output signal corresponding to the detected in-cylinder pressure is provided near the tip of the fuel injection valve,
The fuel injection control device includes:
Based on the output signal from the in-cylinder pressure detecting means, an actual valve opening time detecting means for detecting an actual valve opening time that is an actual valve opening time of the fuel injection valve;
Based on a valve opening time initial value that is an initial value of the valve opening time of the fuel injection valve obtained in advance and the actual valve opening time, the fuel injection valve opening time or the fuel injection valve Correction means for correcting the fuel injection amount injected from
A fuel injection control device comprising: The fuel injection control device according to claim 1,
The correction means is actual valve opening time correction means for correcting the valve opening time when the absolute value of the rate of change of the actual valve opening time with respect to the initial valve opening time value is equal to or greater than a predetermined time threshold. A fuel injection control device. The fuel injection control device according to claim 2,
The actual valve opening time correction means uses a deviation amount of the actual valve opening time with respect to the initial valve opening time as a correction time, and corrects the actual valve opening time with the correction time. . The fuel injection control device according to claim 1,
Based on the actual valve opening time, fuel injection amount calculation means for calculating the fuel injection amount actually injected from the fuel injection valve during the actual valve opening time as an estimated fuel injection amount,
When the absolute value of the rate of change of the estimated fuel injection amount with respect to the injection amount initial value, which is the initial value of the fuel injection amount according to the valve opening time initial value, is equal to or greater than a predetermined injection amount threshold value The fuel injection control device is a fuel injection amount correction means for correcting a fuel injection amount injected from the fuel injection valve. The fuel injection control device according to claim 4, wherein
The fuel injection amount correction means uses a deviation amount of the estimated fuel injection amount with respect to the injection amount initial value as a correction injection amount, and corrects the estimated fuel injection amount with the correction injection amount. . In the fuel-injection control apparatus of any one of Claims 1-5,
The actual valve opening time detecting means extracts a waveform indicating a valve opening operation and a valve closing operation of the fuel injection valve included in the output signal, and detects the actual valve opening time from the extracted waveform. A fuel injection control device. In a fuel injection control method for controlling a fuel injection valve that directly injects fuel into a combustion chamber in a cylinder of an internal combustion engine,
When an in-cylinder pressure in the cylinder is detected by an in-cylinder pressure detecting means provided near the tip of the fuel injection valve, and an output signal corresponding to the detected in-cylinder pressure is output, based on the output signal, Detecting an actual valve opening time that is an actual valve opening time of the fuel injection valve;
Based on a valve opening time initial value that is an initial value of the valve opening time of the fuel injection valve obtained in advance and the actual valve opening time, the fuel injection valve opening time or the fuel injection valve Correcting the fuel injection amount injected from
A fuel injection control method comprising:

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