JP5726232B2 - Control device for internal combustion engine and control method for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine having a diagnostic function for a variable valve timing mechanism.

  A variable valve timing mechanism of an internal combustion engine controls opening and closing timings of an intake valve and an exhaust valve. As a diagnostic device for such a variable valve timing mechanism, the target value of the rotational phase angle of the intake camshaft and the exhaust camshaft (hereinafter referred to as the target rotational phase angle) is greatly changed stepwise, and the target rotational phase angle There is one that detects the presence or absence of an abnormal response of the variable valve timing mechanism by measuring the responsiveness of a measured value (hereinafter referred to as an actual rotational phase angle) of a rotational phase angle to a change (see, for example, Patent Document 1) .

  In Patent Document 1, the deviation between the target rotation phase angle and the actual rotation phase angle is measured when the diagnosis execution time td elapses after the target rotation phase angle of the intake cam shaft and the exhaust cam shaft is greatly changed stepwise. doing. When the rotational phase angle deviation is equal to or greater than a predetermined deviation threshold, it is determined that a response abnormality has occurred in the variable valve timing mechanism.

JP-A-11-002141

However, the prior art has the following problems.
In the control device for an internal combustion engine of Patent Document 1, in order to diagnose the presence or absence of a response abnormality of the variable valve timing mechanism, it is necessary to largely change the target rotational phase angle of the intake cam shaft and the exhaust cam shaft in a step shape.

  However, in a hybrid vehicle, for example, the internal combustion engine is operated quasi-steadyly in a middle-rotation middle load region with good power generation efficiency for the purpose of driving the generator. As a result, there has been a problem that changes in the operating state such as the rotational speed and charging efficiency of the internal combustion engine are reduced, and the target rotational phase angle set according to the operating state cannot be changed greatly.

  As a method for enabling diagnosis of the variable valve timing mechanism even in an internal combustion engine, such as a hybrid vehicle, in which the change in the driving state is small, there is a method of generating a fuel cut.

  In a general internal combustion engine, the target rotational phase angle during fuel cut is set to phase angle change amount = 0 (for example, the intake valve is the most retarded angle), and the target rotational phase angle in the middle rotational load region is An intermediate phase angle is set. Therefore, the target rotation phase angle can be forcibly changed to phase angle change amount = 0 by performing fuel cut during operation in the middle rotation load region.

  However, in this method, in order to stabilize the operation state of the internal combustion engine during fuel cut, it is necessary to rotate the internal combustion engine by a generator, and there is a problem in that battery power is consumed.

  Another method for enabling the variable valve timing mechanism to be diagnosed without causing a fuel cut is to forcibly change the target rotational phase angle. However, this method has a problem that the exhaust emission deteriorates because the overlap between the intake valve and the exhaust valve is not optimally set according to the operating state of the internal combustion engine.

  The present invention has been made to solve the above-described problems. Even in an internal combustion engine with little change in the operating state, whether or not there is an abnormal response of the variable valve timing mechanism by suppressing emission and battery power consumption. It is an object of the present invention to obtain an internal combustion engine control device and an internal combustion engine control method capable of diagnosing the engine.

The control apparatus for an internal combustion engine according to the present invention includes a variable valve timing mechanism that varies the opening / closing timing of at least one of the intake valve and the exhaust valve, and the variable valve timing in a quasi-steady operation state in which a change in the operation state is small. A control device for an internal combustion engine of a hybrid vehicle, which cannot greatly change a target rotational phase angle set in accordance with the operating state for diagnosing a mechanism, and an operating state detecting unit that detects the operating state of the internal combustion engine An ignition timing control unit that sets the basic ignition timing according to the operating state detected by the operating state detection unit, and controls the ignition timing of the internal combustion engine according to the set basic ignition timing, and the rotation phases of the intake valve and the exhaust valve The actual rotation phase angle detection unit that detects the actual measured value of the angle as the actual rotation phase angle, and the operation state detected by the operation state detection unit A target rotation phase angle calculation unit that calculates a target value of the rotation phase angle of the intake valve and the exhaust valve as a target rotation phase angle, a target rotation phase angle calculated by the target rotation phase angle calculation unit, and an actual rotation phase angle detection unit The actual rotational phase angle follows the target rotational phase angle on the basis of the rotational phase angle deviation calculating unit that calculates the deviation dr from the actual rotational phase angle detected in step 1 and the deviation dr calculated by the rotational phase angle deviation calculating unit. As described above, from the rotational phase angle control unit that controls the variable valve timing mechanism and the magnitude of the deviation dr that changes according to the control by the rotational phase angle control unit, the variable valve timing mechanism is diagnosed for the presence or absence of a response abnormality. and a valve timing mechanism diagnosis unit, the variable valve timing mechanism diagnostic unit, the operating state detected by the operating condition detecting unit, emission by performing a diagnostic is deteriorated semidefinite A diagnosis execution condition determination unit that outputs a diagnosis permission signal when it is determined that a preset diagnosis execution condition that indicates an operating state is satisfied, and a target rotation phase angle calculation unit that outputs a diagnosis permission signal In contrast, the target rotational phase angle switching unit that instructs to switch the target rotational phase angle to a preset diagnostic target value, the operating state, and the retard amount of the ignition timing for suppressing emissions When a diagnosis point fire timing correction amount map indicating a correspondence relationship with the correction amount at diagnosis is stored in advance, and when a diagnosis permission signal is input, according to the diagnosis point fire timing correction amount map stored in the storage unit, Calculate the correction amount at diagnosis according to the operation state detected by the operation state detection unit, and subtract the correction amount at diagnosis from the basic ignition timing set by the ignition timing control unit to determine the ignition timing at the time of diagnosis The diagnosis time-of-fire correction unit and the target rotation phase angle are switched to the target value for diagnosis, and control by the rotation phase angle control unit is started based on the diagnosis time of fire timing by the diagnosis time-of-fire correction unit If the deviation dr calculated by the rotational phase angle deviation calculation unit after the elapse of the preset diagnosis execution time td satisfies the relationship of | deviation dr | ≧ | predetermined deviation threshold dj | And an abnormality determination unit that determines that a response abnormality has occurred.

An internal combustion engine control method according to the present invention is an internal combustion engine control method used in the internal combustion engine control device according to the present invention, and is detected by the operating state detection unit in the variable valve timing mechanism diagnosis unit. When it is determined that the operation state satisfies a preset diagnosis execution condition indicating that the operation state is a quasi-steady operation state, a diagnosis execution condition determination step for outputting a diagnosis permission signal, and when a diagnosis permission signal is input, When a target rotation phase angle switching step for instructing the target rotation phase angle calculation unit to switch the target rotation phase angle to a preset target value for diagnosis and a diagnosis permission signal are input, stored in the storage unit In accordance with the diagnosis time-of-fire timing correction amount map, the correction amount at diagnosis according to the driving state detected by the driving state detection unit is calculated, and the basic set by the ignition timing control unit is calculated. By subtracting the correction amount at diagnosis from the fire timing, the diagnosis timing fire timing correction step for correcting the ignition timing as the diagnosis timing fire timing, and the target rotation phase angle is switched to the diagnosis target value, and the diagnosis timing fire timing correction section The deviation dr calculated by the rotational phase angle deviation calculation unit after the diagnosis execution time td that has been set in advance has elapsed since the start of the control by the rotational phase angle control unit based on the diagnosis timing fire timing by And an abnormality determining step for determining that a response abnormality has occurred in the variable valve timing mechanism when a predetermined deviation threshold value dj | is satisfied.

  According to the present invention, the ignition timing of the internal combustion engine is corrected in accordance with a pre-diagnosis time-of-fire timing correction amount map during diagnosis of the variable valve timing mechanism in which emissions deteriorate. As a result, an internal combustion engine control device and a control method for an internal combustion engine capable of diagnosing the presence or absence of an abnormal response of the variable valve timing mechanism by suppressing emissions and battery power consumption even in an internal combustion engine with a small change in operating state Can be obtained.

It is an illustration figure which shows the structure of a general hybrid vehicle. It is an illustration figure which shows the structure of the internal combustion engine in Embodiment 1 of this invention. It is a block diagram which shows the structure of the control apparatus of the internal combustion engine in Embodiment 1 of this invention. 3 is a timing chart of the control device for the internal combustion engine when a sticking abnormality has occurred in the exhaust valve in the first embodiment of the present invention. 3 is a timing chart of the control device for the internal combustion engine when the variable valve timing mechanism is normal in Embodiment 1 of the present invention. It is an illustration figure of the diagnosis time-of-fire timing correction amount map which shows the relationship between the correction amount at the time of diagnosis of the ignition timing for suppressing emission, and the operating state of an internal combustion engine in Embodiment 1 of this invention. It is a flowchart which shows the process of the variable valve timing mechanism diagnostic part in Embodiment 1 of this invention.

  Hereinafter, preferred embodiments of an internal combustion engine control device and an internal combustion engine control method according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated about the part which is the same or it corresponds in each figure.

Embodiment 1 FIG.
FIG. 1 is an exemplary diagram showing a configuration of a general hybrid vehicle. First, the mechanism of the hybrid vehicle will be described with reference to FIG.

  In the hybrid vehicle, AC power is generated by driving the generator 5 using the internal combustion engine 1. Further, when the vehicle is decelerated, AC power can also be generated by operating the motor 6 as a generator using the rotation of the drive wheels 9. Output power of the generator 5 and the motor 6 is converted into DC power by the inverter 7 and stored in the battery 8.

  On the other hand, when the vehicle is driven, the drive wheels 9 are rotated by driving the motor 6 with the electric power stored in the battery 8. Further, when starting the internal combustion engine 1, the generator 5 can be driven by the electric power stored in the battery 8 to rotate the internal combustion engine 1.

  FIG. 2 is an exemplary diagram showing a configuration of the internal combustion engine 1 according to Embodiment 1 of the present invention. Hereinafter, the components and functions of the internal combustion engine 1 will be described with reference to FIG.

  The internal combustion engine 1 shown in FIG. 2 includes a variable valve timing mechanism 10, an intake valve 11, an exhaust valve 12, a crankshaft 13, a spark plug 14, a throttle valve 15, an injector 16, a catalytic converter 17, an intake cam angle sensor S11, and an exhaust cam. An angle sensor S12, a crank angle sensor S13, a throttle sensor S15, an airflow sensor S16, an air-fuel ratio sensor S17, and an oxygen concentration sensor S18 are provided.

  The variable valve timing mechanism 10 includes an intake cam shaft 101 and an exhaust cam shaft 102.

  The intake camshaft 101 drives the intake valve 11 to open and close in synchronization with the rotation of the crankshaft 13. Similarly, the exhaust camshaft 102 opens and closes the exhaust valve 12 in synchronization with the rotation of the crankshaft 13. At this time, the advance amounts of the intake camshaft 101 and the exhaust camshaft 102 with respect to the crankshaft 13 are adjusted by the hydraulically driven variable valve timing mechanism 10.

  The actual rotation phase angle of the intake valve 11 is calculated by obtaining a relative rotation angle of the intake cam angle phase measured by the intake cam angle sensor S11 with respect to the crank angle phase measured by the crank angle sensor S13. Similarly, the actual rotation phase angle of the exhaust valve 12 is calculated by obtaining the relative rotation angle of the exhaust cam angle phase measured by the exhaust cam angle sensor S12 with respect to the crank angle phase measured by the crank angle sensor S13. .

  An air flow sensor S <b> 16 that measures the amount of intake air taken into the cylinder is attached to the intake pipe of the internal combustion engine 1. Further, a throttle valve 15 for adjusting the intake air amount is provided further downstream of the intake pipe. The opening degree of the throttle valve 15 is detected by a throttle sensor S15 installed in the vicinity. An injector 16 for supplying fuel into the cylinder is provided near the intake port of the intake pipe.

  An exhaust pipe of the internal combustion engine 1 includes a catalytic converter 17 that purifies exhaust gas discharged from the cylinder, an air-fuel ratio sensor S17 that detects an air-fuel ratio of the exhaust gas, and an oxygen concentration that indicates an oxygen concentration downstream of the catalytic converter 17. A sensor S18 is provided.

  The control device 2 (ECU) for the internal combustion engine controls the ignition timing of the spark plug 14 provided for each cylinder, the opening of the throttle valve 15, the fuel injection amount of the injector 16, and the like, and the variable valve timing mechanism 10 It has a diagnostic function.

  FIG. 3 is a block diagram showing the configuration of the control device 2 for the internal combustion engine in the first embodiment of the present invention. Hereinafter, the components and functions of the control device 2 for an internal combustion engine will be described with reference to FIG.

  The control device 2 for the internal combustion engine shown in FIG. 3 includes an operating state detection unit M1, an ignition timing control unit M2, a target rotation phase angle calculation unit M3, an actual rotation phase angle detection unit M4, a rotation phase angle deviation calculation unit M5, and a rotation phase. An angle control unit M6 and a variable valve timing mechanism diagnosis unit 20 are provided.

  The variable valve timing mechanism diagnosis unit 20 includes a diagnosis execution condition determination unit M7, a target rotation phase angle switching unit M8, an abnormality determination unit M9, and a diagnosis time point fire timing correction unit M10.

  The operating state detection unit M1 detects the operating state such as the rotational speed and charging efficiency of the internal combustion engine 1 based on the measured values of the crank angle sensor S13, the airflow sensor S16, the air-fuel ratio sensor S17, and the like.

  The ignition timing control unit M2 sets a basic ignition timing that is a target value of the ignition timing of the internal combustion engine 1 according to the operating state of the internal combustion engine 1 detected by the operating state detection unit M1, and the internal combustion engine according to the set basic ignition timing. The ignition timing of the engine 1 is controlled.

  The target rotation phase angle calculation unit M3 calculates the target value of the rotation phase angle of the intake valve 11 and the exhaust valve 12 as the target rotation phase angle according to the operation state of the internal combustion engine 1 detected by the operation state detection unit M1. In general, the overlap between the intake valve 11 and the exhaust valve 12 is set to be larger as the internal combustion engine 1 has a higher rotational speed and load.

  The actual rotation phase angle detection unit M4 obtains the relative rotation angle between the cam angle phase measured by the intake cam angle sensor S11 and the exhaust cam angle sensor S12 and the crank angle phase measured by the crank angle sensor S13, thereby obtaining the intake valve. 11 and the actual measured value of the rotational phase angle of the exhaust valve 12 are detected as the actual rotational phase angle.

  The rotation phase angle deviation calculation unit M5 compares the calculation results of the target rotation phase angle calculation unit M3 and the actual rotation phase angle detection unit M4, and calculates a deviation dr between the target rotation phase angle and the actual rotation phase angle.

  The rotation phase angle control unit M6 controls the variable valve timing mechanism 10 based on the output of the rotation phase angle deviation calculation unit M5 so that the actual rotation phase angle follows the target rotation phase angle.

  Next, components and functions of the variable valve timing mechanism diagnosis unit 20 of the control device 2 for the internal combustion engine will be described.

  The diagnosis execution condition determination unit M7 determines a condition for executing the diagnosis of the variable valve timing mechanism 10. Specifically, the operating state such as the rotational speed and charging efficiency of the internal combustion engine 1 is continuously within a predetermined change width for a diagnosis condition determination time tj (for example, 10 sec) or more, that is, the operating state is quasi. When it is confirmed that it is in a steady state, it is determined that the diagnosis execution condition is satisfied. Then, a diagnosis permission signal is output to the target rotation phase angle switching unit M8.

  When the target rotation phase angle switching unit M8 receives the diagnosis permission signal from the diagnosis execution condition determination unit M7, the target rotation phase angle is set to the target value for diagnosis (for example, phase angle change amount = 0: the intake valve is the most retarded angle). The target rotation phase angle calculation unit M3 is instructed to switch. As a result, the target rotational phase angle calculation unit M3 greatly changes the target rotational phase angle to the diagnostic target value in a step shape.

  The abnormality determination unit M9 measures the response of the actual rotation phase angle. Specifically, the deviation dr between the target rotation phase angle and the actual rotation phase angle when the diagnosis execution time td has elapsed after the target rotation phase angle has been switched to the diagnosis target value is a predetermined deviation threshold value. If it is greater than or equal to dj (for example, 25 ° crank angle), it is determined that a response abnormality has occurred in the variable valve timing mechanism 10. Here, the diagnosis execution time td is set to a time sufficient for the actual rotation phase angle to follow the target rotation phase angle (for example, 5 sec).

  In this way, even in the internal combustion engine 1 such as a hybrid vehicle in which the change in the driving state is small, it is possible to diagnose the presence or absence of a response abnormality of the variable valve timing mechanism 10, and the intake valve 11 or the exhaust valve 12 mechanism. It is possible to detect the deterioration of the responsiveness, the abnormal sticking of the variable valve timing mechanism 10, and the like.

  FIG. 4 is a timing chart of the control device 2 for the internal combustion engine when a sticking abnormality has occurred in the exhaust valve 12 in the first embodiment of the present invention. Hereinafter, a method for detecting the presence or absence of a response abnormality of the variable valve timing mechanism 10 will be described with reference to FIG.

  The diagnosis execution condition determination unit M7 determines the range of change in which the operating state (a) such as the rotational speed and the charging efficiency of the internal combustion engine 1 continues for the diagnosis condition determination time tj or more during the diagnosis condition determination (1) period. Confirm that it is within. At time t1, the fact that the diagnosis execution condition is satisfied is output as a diagnosis permission signal (b) to the target rotation phase angle switching unit M8.

  The target rotation phase angle switching unit M8 inputs the diagnosis permission signal (b) from the diagnosis execution condition determination unit M7, and at the same time, sets the target value of the rotation phase angle (c) for diagnosis to the target rotation phase angle calculation unit M3. It is instructed to switch to. As a result, as shown by the dotted line in FIG. 4, at the time t1, the target value of the rotational phase angle (c) changes greatly in a step shape.

  In FIG. 4, since the sticking abnormality has occurred in the exhaust valve 12, the measured value of the rotational phase angle (c) of the exhaust valve 12 is the time t2 when the diagnosis execution time td has elapsed, as shown by the solid line in FIG. But it is not following the target value. As a result, in the exhaust valve 12, the relationship | deviation dr | ≧ | deviation threshold value dj | is established, so the abnormality determination unit M9 determines that a response abnormality has occurred in the exhaust valve 12.

  On the other hand, the actual measured value of the rotational phase angle (c) of the intake valve 11 can follow the target value during the execution of the diagnosis (2), as shown by the solid line in FIG. 4, and | devr dr | ≧ | deviation threshold Since the relationship dj | is not established, the abnormality determination unit M9 determines that no response abnormality has occurred in the intake valve 11.

  The abnormality determination unit M9 outputs an abnormality determination (f) to the outside at the end of diagnosis (3).

  For simplicity, FIG. 4 shows a timing chart in which the ignition timing (d) and the intake air amount (e) are constant. However, as will be described later with reference to FIG. During the diagnosis of the timing mechanism 10, the exhaust emission can be suppressed by controlling the ignition timing (d) and the intake air amount (e).

  FIG. 5 is a timing chart of the control device 2 for the internal combustion engine when the variable valve timing mechanism 10 is normal in the first embodiment of the present invention. Hereinafter, the exhaust emission during diagnosis of the variable valve timing mechanism 10 will be described with reference to FIG.

  The timing chart shown in FIG. 5 differs from the timing chart shown in FIG. 4 in that the variable valve timing mechanism 10 is normal and the exhaust valve 12 is not stuck abnormally. Specifically, the measured value of the rotational phase angle (c) of the exhaust valve 12 follows the target value, and as a result, the abnormality determination unit M9 does not output the abnormality determination (f) to the outside.

  By the way, in the internal combustion engine 1 that employs the variable valve timing mechanism 10, it is common to provide an overlap amount between the intake valve 11 and the exhaust valve 12 in the middle to high rotation range. It is known that by increasing the overlap, the residual gas in the cylinder is increased, an internal EGR (Exhaust Gas Recirculation) effect is produced, and the combustion temperature is lowered, so that emissions such as NOx can be suppressed. It has been.

  However, as described above in “Problems to be Solved by the Invention”, if the target rotational phase angle is forcibly changed for diagnosis of the variable valve timing mechanism 10, the intake valve 11 and the exhaust valve 12 may be overloaded. Since the lap is not optimally set according to the operating state of the internal combustion engine 1, there is a problem that exhaust emission is deteriorated.

  For example, in FIG. 5, since the target rotational phase angle is set to 0 for the purpose of diagnosis, the overlap between the intake valve 11 and the exhaust valve 12 is almost 0 at time t3. As a result, the internal EGR amount (g) decreases and the combustion temperature (h) rises, so that the emission (i) such as NOx is deteriorated.

  Therefore, the variable valve timing mechanism diagnosis unit 20 according to the first embodiment includes a diagnosis time point fire timing correction unit M10 as shown in FIG. It is known as a characteristic relating to NOx emission that if the ignition timing is delayed, the start of combustion is delayed and combustion progresses during the expansion stroke to lower the combustion temperature, so that the generation of NOx is suppressed. The variable valve timing mechanism diagnosing unit 20 according to the first embodiment uses this characteristic to suppress the emission of NOx and the like at the time of diagnosis by performing an ignition timing correction process.

  Specifically, the diagnosis execution condition determination unit M7 transmits a diagnosis permission signal to the target rotation phase angle switching unit M8 when the diagnosis execution condition is satisfied, and at the same time to the diagnosis time point fire timing correction unit M10. Also outputs a diagnosis permission signal. When the diagnosis timing fire timing correction unit M10 receives the diagnosis permission signal, the ignition timing correction amount (retard amount) of the ignition timing is calculated according to the operation state of the internal combustion engine 1 output by the operation state detection unit M1. And output to the ignition timing control unit M2.

  As a result, the ignition timing control unit M2 reflects the ignition timing correction amount output from the diagnosis timing fire timing correction unit M10, and the ignition timing (d) and intake air of the internal combustion engine 1 as shown in FIG. By correcting and controlling the amount (e), emission can be suppressed.

  FIG. 6 is an exemplary diagram of a diagnosis timing ignition timing correction amount map showing the relationship between the ignition timing correction amount for suppressing emissions and the operating state of the internal combustion engine 1 in Embodiment 1 of the present invention. .

  The diagnosis time-of-fire timing correction amount map shown in FIG. 6 is set so that the retard amount of the ignition timing increases because the combustion speed increases as the operating state of the internal combustion engine 1 increases or the load increases. Yes. However, the ignition timing is set in a range that does not significantly impair the performance because the generated torque is greatly reduced and the power generation performance is impaired if the ignition timing is retarded too much.

  During the diagnosis of the variable valve timing mechanism 10, the diagnosis timing fire timing correction unit M10 diagnoses the ignition timing according to the operating state of the internal combustion engine 1 according to a diagnosis time fire timing correction amount map created in advance in a storage unit (not shown). A time correction amount (retard amount) is calculated and output to the ignition timing control unit M2.

The ignition timing control unit M2 calculates the ignition timing at the time of diagnosis according to the following equation.
Diagnosis time ignition timing (advance amount) = basic ignition timing (including various corrections) −diagnosis correction amount As described above, the ignition timing control unit M2 performs basic ignition that is variously corrected according to the operating state of the internal combustion engine 1. Further, the amount of correction at the time of diagnosis is reflected in the time period to suppress emission of NOx or the like when the overlap amount at the time of diagnosis = 0.

  FIG. 7 is a flowchart showing processing of the variable valve timing mechanism diagnosis unit 20 according to Embodiment 1 of the present invention.

  In step S701, the operating state detection unit M1 detects the operating state such as the rotational speed and charging efficiency of the internal combustion engine 1 based on the measured values of the crank angle sensor S13, the airflow sensor S16, the air-fuel ratio sensor S17, and the like.

  Next, in step S702, the diagnosis implementation condition determination unit M7 determines whether or not the measured value of the rotational speed of the internal combustion engine 1 is within a predetermined rotational speed variation range. If no, the process returns to step S701. If yes, the process proceeds to step S703.

  Next, in step S703, the diagnosis execution condition determination unit M7 determines whether or not the measured value of the charging efficiency of the internal combustion engine 1 is within a predetermined variation range of the charging efficiency. If no, the process returns to step S701. If yes, the process proceeds to step S704.

  Next, in step S704, the diagnosis execution condition determination unit M7 determines whether or not the period in which the measured values of the rotational speed and the charging efficiency are within a predetermined change width continues for the diagnosis condition determination time tj or more. . If no, the process returns to step S701. If yes, the process proceeds to step S705.

  Next, in step S705, the diagnosis execution condition determination unit M7 determines that the diagnosis execution condition is satisfied, and outputs a diagnosis permission signal to the target rotation phase angle switching unit M8 and the diagnosis time point fire timing correction unit M10.

  Next, in step S706, the target rotation phase angle switching unit M8 controls the target rotation phase angle calculation unit M3 to switch the target rotation phase angle to the diagnostic target value. As a result, the target rotation phase angle changes greatly in steps.

  Next, in step S707, the diagnosis timing fire timing correction unit M10 performs the ignition timing correction amount (retard amount) according to the operating state of the internal combustion engine 1 according to the diagnosis timing fire timing correction amount map shown in FIG. Is output to the ignition timing control unit M2.

  Next, in step S708, the ignition timing control unit M2 suppresses the emission at the time of diagnosis by further reflecting the amount of correction at the time of diagnosis in the basic ignition timing corrected in accordance with the operating state of the internal combustion engine 1. To do.

  Next, in step S709, the abnormality determination unit M9 determines whether or not the diagnosis execution time td has elapsed since the diagnosis permission signal was received. If no, the process returns to step S701. If yes, the process proceeds to step S710.

  Next, in step S710, the abnormality determination unit M9 determines whether or not the deviation dr between the target rotation phase angle and the actual rotation phase angle satisfies a relationship of | deviation dr | ≧ | deviation threshold value dj |.

  In step S710, when it is No, it progresses to step S711, determines with the variable valve timing mechanism 10 being normal, and complete | finishes a process. On the other hand, if Yes in step S710, the process proceeds to step S712, and it is determined that an abnormality has occurred in the variable valve timing mechanism 10. In step S713, the abnormality determination unit M9 turns on a failure lamp or the like of the vehicle to notify the driver of the occurrence of abnormality, and ends the process.

  As described above, according to the first embodiment, the ignition timing of the internal combustion engine is corrected according to the previously prepared diagnosis time-of-fire timing correction amount map during the diagnosis of the variable valve timing mechanism in which the emission is deteriorated. As a result, an internal combustion engine control device and a control method for an internal combustion engine capable of diagnosing the presence or absence of an abnormal response of the variable valve timing mechanism by suppressing emissions and battery power consumption even in an internal combustion engine with a small change in operating state Can be obtained.

  DESCRIPTION OF SYMBOLS 1 Internal combustion engine, 2 Internal combustion engine control apparatus, 5 Generator, 6 Motor, 7 Inverter, 8 Battery, 9 Drive wheel, 10 Variable valve timing mechanism, 11 Intake valve, 12 Exhaust valve, 13 Crankshaft, 14 Spark plug, 15 throttle valve, 16 injector, 17 catalytic converter, 20 variable valve timing mechanism diagnosis unit, 101 intake camshaft, 102 exhaust camshaft, S11 intake cam angle sensor, S12 exhaust cam angle sensor, S13 crank angle sensor, S15 throttle sensor, S16 air flow sensor, S17 air-fuel ratio sensor, S18 oxygen concentration sensor, M1 operating state detection unit, M2 ignition timing control unit, M3 target rotation phase angle calculation unit, M4 actual rotation phase angle detection unit, M5 rotation phase angle deviation calculation unit, M6 rotation phase angle controller, M7 diagnosis Implementation condition determination unit, M8 target rotational phase angle switching unit, M9 abnormality determination unit, M10 diagnosis timing fire timing correction unit.

Claims (3)

In a quasi-steady operation state in which a change in the operation state is small, a variable valve timing mechanism that varies at least one of the opening and closing timings of the intake valve and the exhaust valve is provided . A control device for an internal combustion engine of a hybrid vehicle that cannot greatly change the target rotational phase angle set by
An operating state detector for detecting an operating state of the internal combustion engine;
An ignition timing control unit that sets a basic ignition timing according to the operating state detected by the operating state detection unit, and controls the ignition timing of the internal combustion engine according to the set basic ignition timing;
An actual rotational phase angle detector that detects the actual measured rotational phase angles of the intake valve and the exhaust valve as actual rotational phase angles;
A target rotation phase angle calculation unit that calculates a target value of the rotation phase angle of the intake valve and the exhaust valve as a target rotation phase angle according to the operation state detected by the operation state detection unit;
A rotational phase angle deviation calculating unit that calculates a deviation dr between the target rotational phase angle calculated by the target rotational phase angle calculating unit and the actual rotational phase angle detected by the actual rotational phase angle detecting unit;
A rotational phase angle controller that controls the variable valve timing mechanism so that the actual rotational phase angle follows the target rotational phase angle based on the deviation dr calculated by the rotational phase angle deviation calculator;
A variable valve timing mechanism diagnosing unit that diagnoses the presence or absence of a response abnormality of the variable valve timing mechanism from the magnitude of the deviation dr that changes according to control by the rotational phase angle control unit;
The variable valve timing mechanism diagnostic unit is
Diagnosis when it is determined that the operation state detected by the operation state detection unit satisfies a predetermined diagnosis execution condition indicating that the operation state is the quasi-steady operation state in which emission deteriorates by performing diagnosis A diagnosis execution condition determination unit that outputs a permission signal;
A target rotation phase angle switching unit that instructs the target rotation phase angle calculation unit to switch the target rotation phase angle to a preset diagnostic target value when the diagnosis permission signal is input;
A storage unit in which a diagnosis time point ignition timing correction amount map indicating a correspondence relationship between the operation state and a diagnosis time correction amount corresponding to a retard amount of the ignition timing for suppressing emission is stored;
When the diagnosis permission signal is input, according to the diagnosis time point fire timing correction amount map stored in the storage unit, a diagnosis correction amount corresponding to the driving state detected by the driving state detection unit is calculated, A diagnosis timing fire timing correction section that corrects the ignition timing as a diagnosis timing fire timing by subtracting the diagnosis correction amount from the basic ignition timing set by the ignition timing control section;
The target rotational phase angle is switched to the target value for diagnosis, and the diagnostic phase set in advance is started after the control by the rotational phase angle control unit is started based on the diagnostic timing ignition timing by the diagnostic timing ignition timing correction unit. The deviation dr calculated by the rotational phase angle deviation calculating unit after the elapse of time td is:
| The deviation dr | ≧ | predetermined deviation threshold dj |
And an abnormality determining unit that determines that the response abnormality has occurred in the variable valve timing mechanism when the relationship is satisfied. The control apparatus for an internal combustion engine according to claim 1,
The operating state detection unit detects the rotational speed and charging efficiency of the internal combustion engine as the operating state of the internal combustion engine,
The diagnosis execution condition determination unit is configured such that the rotation speed detected by the operation state detection unit is within a first allowable change range, and the charging efficiency detected by the operation state detection unit is a second allowable change. A control device for an internal combustion engine that determines that the diagnosis execution condition is satisfied when a state within the range continues for a diagnosis condition determination time tj or longer. An internal combustion engine control method used in the control apparatus for an internal combustion engine according to claim 1,
In the variable valve timing mechanism diagnostic unit,
The operating state the operating state detected by the detection unit, wherein when it is determined that the preset diagnosis execution condition is satisfied indicates that the quasi-steady operating condition, diagnosis execution condition determination step of outputting diagnosis permission signal When,
A target rotation phase angle switching step for instructing the target rotation phase angle calculation unit to switch the target rotation phase angle to a preset diagnostic target value when the diagnosis permission signal is input;
When the diagnosis permission signal is input, according to the diagnosis time point fire timing correction amount map stored in the storage unit, a diagnosis correction amount corresponding to the driving state detected by the driving state detection unit is calculated, A diagnosis timing fire timing correction step of correcting the ignition timing as a diagnosis timing fire timing by subtracting the diagnosis correction amount from the basic ignition timing set by the ignition timing control unit;
The target rotational phase angle is switched to the target value for diagnosis, and the diagnostic phase set in advance is started after the control by the rotational phase angle control unit is started based on the diagnostic timing ignition timing by the diagnostic timing ignition timing correction unit. The deviation dr calculated by the rotational phase angle deviation calculating unit after the elapse of time td is:
| The deviation dr | ≧ | predetermined deviation threshold dj |
An abnormality determination step for determining that the response abnormality has occurred in the variable valve timing mechanism when the relationship is satisfied.

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