JP2010106763A - Control device for internal combustion engine and internal combustion engine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compatibly materialize the reduction of concerns of inability to control to a desired engine operation state and the reduction of electric power quantity consumed by an aero flow sensor. <P>SOLUTION: In a control device for an internal combustion engine applied to an internal combustion engine provided with a thermal type aero flow sensor comprising a heat generating resistor (heater) and temperature sensitive resistor (temperature detection element), setting a target injection quantity of fuel using a detection value of the aero flow sensor, and controlling the operation of a fuel injection valve so as to set an injection quantity to the target injection quantity, a chip type aero flow sensor composed of a heater formed in a film-state is adopted as the aero flow sensor. Electric power supply to the aero flow sensor (heat generating resistor) is stopped during injection stop period during which the fuel injection valve is controlled to stop fuel injection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine applied to an internal combustion engine including a thermal airflow sensor configured to include a heater and a temperature detection element.

  Conventionally, an intake flow rate is detected by an air flow sensor, a target injection amount of fuel is set based on the detected intake flow rate so as to achieve a desired air-fuel ratio (for example, a theoretical air-fuel ratio), and fuel injection is performed so that the set target injection amount is achieved. Engines (internal combustion engines) that control the operation of valves are known.

  Such an airflow sensor includes a thermal airflow sensor configured by arranging a heater and a temperature detecting element side by side. The heater is configured by forming a heat wire that generates heat when energized in a bobbin shape, and the temperature detecting element is configured by forming a heat wire that changes in electrical resistance according to temperature in a bobbin shape. Then, it is common to calculate the intake air flow rate based on the detected value of the temperature sensing element when a predetermined amount of electricity is supplied to the heater, or the amount of electricity supplied when the heater is supplied with current so that the detected value becomes a predetermined value. (See Patent Document 1).

  Here, it takes several seconds (preparation time) for the heater temperature to rise to such an extent that the intake air flow rate can be accurately calculated after supplying power to the air flow sensor and starting energizing the heater. Therefore, when the engine is started, the intake flow rate cannot be accurately calculated until this preparation time has elapsed. Therefore, since the target injection amount described above cannot be set until the preparation time elapses, there is a concern that the engine cannot be controlled to a desired engine operating state such as exhaust emission deterioration.

In response to this concern, the control device described in Patent Document 1 supplies power to the air flow sensor and energizes the heater even when the engine is stopped, thereby controlling the heater temperature to be sufficiently high when the engine is started. ing.
JP 7-317584 A

  However, in the above control device, since the power supply to the air flow sensor is continued while the engine is stopped in a situation in which it is not known when the engine starts, the above-mentioned concern that it becomes impossible to control to the desired engine operating state can be solved, As a contradiction, the amount of power consumed by the heater increases.

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to achieve both a reduction in concern that the engine cannot be controlled to a desired engine operating state and a reduction in power consumption by the airflow sensor. Another object of the present invention is to provide a control device and a control system for an internal combustion engine.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention according to claim 1 is applied to an internal combustion engine including an airflow sensor configured to include a heater and a temperature sensing element, and a fuel injection valve that injects fuel to be used for combustion of the internal combustion engine (engine). In a control device for an internal combustion engine that sets a target fuel injection amount using a detection value of the air flow sensor and controls the operation of the fuel injection valve so as to be the target fuel injection amount, the air flow sensor includes the heater In the injection stop period in which the fuel injection valve is controlled to stop fuel injection, power supply to the air flow sensor is stopped. .

  As described above, in the present invention, since the power supply to the air flow sensor is stopped during the injection stop period, the power consumption of the air flow sensor (heater) can be reduced. However, if the power supply is stopped in this way, energization to the heater must be started when fuel injection is started, and the target fuel injection amount cannot be set during the above-described preparation time. There is a concern that it will become impossible to control the engine operating state. On the other hand, in this invention, the said concern is reduced by employ | adopting the airflow sensor of the structure demonstrated below.

  That is, in the above-described Patent Document 1, an air flow sensor in which a heater is formed in a bobbin shape is employed. In contrast, the present invention employs an airflow sensor in which a heater is formed in a film shape, and this film heater can be easily reduced in size so as to have a smaller heat capacity than a bobbin-shaped heater. Therefore, the preparation time required to rise to a predetermined temperature after the energization of the film heater is started can be shortened compared to the case of the bobbin heater. Specifically, the preparation time for the bobbin-shaped heater is generally several seconds, whereas the preparation time for the film-shaped heater is several milliseconds.

  As described above, according to the present invention, since the power supply to the airflow sensor is stopped during the injection stop period while adopting the airflow sensor of the film heater, the concern that it becomes impossible to control to the desired engine operating state, It is possible to achieve both reduction in power consumption.

  Incidentally, it is desirable to reduce the size of the airflow sensor by forming the temperature sensing element in the same manner as the heater.

  According to a second aspect of the present invention, the internal combustion engine is provided with another sensor for detecting a physical quantity (for example, engine rotational speed NE) correlated with the intake air flow rate, in addition to the air flow sensor. An estimation means for estimating the intake flow rate by substituting the detection value by another sensor into the model formula, a calculation means for calculating the intake flow rate based on the detection value by the air flow sensor, and the / based on the estimation value by the estimation means A correction unit that sets a target injection amount and corrects the model formula based on a difference between a value calculated by the calculation unit and the estimated value, and the airflow sensor forms the temperature detecting element in a film shape It is characterized by being comprised.

  Contrary to the invention of claim 2 above, if the target injection amount is set based on the calculated value of the intake flow rate using the detected value of the air flow sensor, the fuel injection is started although the preparation time in the film heater is short. The target injection amount cannot be set until the preparation time elapses from the time when the fuel injection is performed. On the other hand, according to the second aspect of the invention, since the target injection amount is set based on the intake flow rate (estimated value) estimated by substituting the detection value of the other sensor into the model formula, the preparation time elapses. Even if not, the target injection amount can be set.

  However, since the estimated value obtained by the other sensor is less accurate than the calculated value obtained by the air flow sensor, it is difficult to accurately control the desired engine operating state. In order to solve this problem, the invention according to claim 2 solves the above problem by correcting the model formula used for the intake flow rate estimation based on the difference between the calculated value and the estimated value of the intake flow rate.

  In addition, since a film-like heater with a short preparation time is employed, the time from the start of energization to the heater to the correction of the model formula after the preparation time has elapsed (see T11 in FIG. 4) is shortened. it can. Therefore, it is possible to shorten the time after the fuel injection is started until the fuel can be accurately controlled to a desired engine operating state.

  According to a third aspect of the present invention, the air flow sensor is configured so that a preparation time required for the heater temperature to reach a predetermined temperature after the energization of the heater is started is shorter than an estimation calculation period by the estimation means. Is constructed.

  When the estimation unit estimates and updates the intake flow rate for each estimation calculation cycle, for example, when calculating the current estimated value based on the previously calculated estimated value, the preparation time is shorter than the estimated calculation cycle. According to the invention described in Item 3, the correction of the model formula by the correcting means can be completed between the previous calculation estimation and the current calculation estimation. Therefore, since it is possible to avoid the concern that the preparation time requires an estimation error of the estimation means, the estimation accuracy of the intake flow rate by the estimation means can be improved.

  The invention according to claim 4 is applied to an internal combustion engine comprising an airflow sensor having a heater and a temperature sensing element, and a fuel injection valve for injecting fuel to be used for combustion of the internal combustion engine. In a control device for an internal combustion engine that sets a target fuel injection amount using a detection value of a sensor and controls the operation of the fuel injection valve so as to achieve the target fuel injection amount, the fuel injection valve stops the fuel injection. During the injection stop period during which the air flow is controlled, the power supply to the air flow sensor is stopped.

  According to the fourth aspect of the invention, since the power supply to the air flow sensor is stopped during the injection stop period, the amount of power consumed by the air flow sensor (heater) can be reduced. However, the preparation time of the bobbin heater is generally several seconds, but it becomes impossible to control the engine to a desired engine operation state by adopting a bobbin heater that can realize the preparation time of several milliseconds. The present invention needs to reduce such concerns.

  The invention described in claim 5 is an internal combustion engine control system comprising the internal combustion engine control device and at least one of an air flow sensor and a fuel injection valve. According to this internal combustion engine control system, the various effects described above can be exhibited in the same manner.

  Hereinafter, an embodiment in which a control device for an internal combustion engine according to the present invention is applied to a control device for an in-vehicle internal combustion engine will be described with reference to the drawings.

  FIG. 1 shows an outline of an engine system according to the present embodiment.

  As an engine 10 (internal combustion engine) to be controlled by this system, a multi-cylinder (for example, 8-cylinder) internal combustion engine for automobiles is assumed. However, in FIG. 1, for convenience of explanation, only one cylinder is shown. The engine 10 shown in FIG. 1 is a 4-stroke spark ignition type reciprocating engine. That is, in the engine 10, for example, for eight cylinders # 1 to # 8 whose cylinder is the cylinder # 1 in the figure, one combustion cycle by four strokes of intake, compression, combustion, and exhaust respectively shifts the strokes between the cylinders. It is executed at a period of “720 ° CA”.

  As shown in the figure, the engine 10 is an intake port injection type internal combustion engine, and is constituted by a cylinder (cylinder) formed by a cylinder block 11. A piston 12 is accommodated in the cylinder block 11, and the output shaft (crankshaft 13) of the engine 10 is rotated by the reciprocating motion of the piston 12. A crank angle sensor 14 (another sensor) is provided in the vicinity of the crankshaft 13. The crankshaft 13 can be given an initial rotation by a starter motor 15.

  A cylinder head 16 is fixed to an upper end surface of the cylinder block 11, and a combustion chamber 10 a is defined by the upper surfaces of the cylinder block 11, the cylinder head 16 and the piston 12. The cylinder head 16 is formed with an intake port (intake port) and an exhaust port (exhaust port) that open to the combustion chamber 10a. These intake port and exhaust port are cams that are linked to the crankshaft 13, respectively. It is opened and closed by an intake valve 17 and an exhaust valve 18 driven by a cam (not shown) attached to the shaft. Further, an intake passage 10b for sucking outside air (fresh air) into each cylinder of the engine 10 is connected to the intake port, and combustion gas (exhaust gas) from each cylinder of the engine 10 is discharged to the exhaust port. For this purpose, an exhaust passage 10c is connected.

  An air flow sensor 19 is provided in the intake passage 10b constituting the intake system of the engine 10 in order to measure the amount of fresh air (intake flow rate) drawn through the air cleaner (not shown) at the most upstream portion of the intake passage 10b. Yes. The air flow sensor 19 of the present embodiment employs a tip type among a bobbin type and a tip type. The chip-type airflow sensor 19 detects a flow rate of intake air passing through the sub-passage and a case 19a that forms a sub-passage that allows a portion of the intake air flowing through the intake passage 10b to be taken in and passed therethrough. And a detection chip 19b.

  FIG. 2 is a diagram showing the structure of the detection chip 19b. As shown in the figure, the detection chip 19b has a heating resistor 192 (heater) and temperature-sensitive resistors 193, 194 (temperature sensing elements) on an insulating substrate 191. Is formed into a film shape. For example, a heat-resistant insulating material such as silicon, polyimide, or ceramic is used for the insulating substrate 191, and the heating resistor 192 and the temperature-sensitive resistors 193 and 194 are formed by depositing platinum or the like on the insulating substrate 191. Form a film. These heating resistors 192 and temperature sensitive resistors 193 and 194 are arranged in the same plane and arranged side by side in the air flow direction (up and down direction in FIG. 2), respectively, on the upstream side and the downstream side of the heating resistor 192. Temperature sensitive resistors 193 and 194 are arranged.

  The heating resistor 192 includes a heating part 192a that is energized and generates heat at a predetermined temperature. Moreover, the temperature sensitive resistors 193 and 194 include flow velocity detectors 193a and 194a whose resistance values change according to temperature. Both ends of each resistor 192, 193, 194 are connected via a lead wire 195 to a control circuit (not shown) housed in the case 19a.

  The heating resistor 192 is held at a predetermined temperature (for example, about 200 ° C.) when energized from the control circuit. The upstream temperature sensitive resistor 193 is cooled by the air flow, whereas the downstream temperature sensitive resistor 194 is heated by the air flow heated by the heating resistor 192. The control circuit detects the air flow direction and calculates the intake flow rate (flow rate per unit time) based on the temperature difference detected by the upstream and downstream temperature sensitive resistors 193 and 191, respectively.

  Returning to the description of FIG. 1, on the downstream side of the air flow sensor 19, an electronically controlled intake throttle valve (throttle valve 20) whose opening degree is electronically adjusted by an actuator 21 such as a DC motor, A throttle sensor 23 (another sensor) is provided for detecting an opening (throttle valve opening) and movement (opening fluctuation). Further, a surge tank 22 in which the passage area of the intake passage 10b is enlarged (expanded) is provided on the downstream side of the throttle valve 20 for the purpose of preventing intake pulsation and intake interference.

  The intake passage 10 b is branched downstream of the surge tank 22 so as to introduce air into the combustion chamber 10 a of each cylinder of the engine 10. An electromagnetically driven (or piezoelectrically driven) fuel injection valve 24 that supplies fuel in the vicinity of the intake port of each cylinder is attached to each branch of the intake passage 10b for each cylinder. In the engine 10, fuel (gasoline) is supplied (port injection) to the intake passage 10b, particularly to the intake port of each cylinder, by the fuel injection valves 24 provided for each cylinder. . The fuel is burned by igniting the fuel injected by the fuel injection valve 24 (strictly, the mixture with intake air). Therefore, a spark plug 25 is attached to each cylinder head 16 of each cylinder of the engine 10. When a high voltage is applied to the spark plug 25, a spark discharge is generated between the opposing electrodes of the spark plug 25, thereby igniting the air-fuel mixture introduced into the combustion chamber 10a and The fuel burns based on the reaction.

  In addition to the above sensors, the engine system is provided with a number of sensors for use in various controls performed in the vehicle. For example, an accelerator operation unit (accelerator pedal) is provided with an accelerator sensor that outputs an electrical signal corresponding to the state (operation amount) in order to detect the amount of accelerator operation by the user.

  The electronic control unit (ECU 30) includes a known microcomputer (not shown) and the like. The ECU 30 grasps the operating state of the engine 10, the engine load, the user's request, etc. based on the detection signals of the various sensors, and controls the operation of the throttle valve 20, the fuel injection valve 24, the spark plug 25, etc. accordingly. By doing so, the operating state of the engine 10 is controlled.

  For example, the required torque is calculated based on the engine rotational speed and the accelerator pedal operation amount, and the target intake air amount (strictly speaking, the amount of air taken into the combustion chamber 10a during one intake stroke in one combustion cycle). ) And the opening degree of the throttle valve 20 is controlled so that the calculated target intake air amount is obtained. Then, the intake air amount Ga actually sucked is calculated by a method that will be described in detail later, and target values for the fuel injection amount, the injection timing, and the ignition timing are set based on the calculated intake air amount Ga, engine speed, and the like. Then, the operation of the fuel injection valve 24 and the spark plug 25 is controlled so that these target values are obtained.

  The target injection amount that is the target value of the fuel injection amount is set to be a desired air-fuel ratio. For example, when it is desired to maximize the exhaust purification rate in a catalyst device (not shown) provided in the exhaust passage 10c, the target injection amount is set according to the intake air amount Ga so that the air-fuel ratio becomes the stoichiometric air-fuel ratio.

  Next, a method for calculating the intake air amount Ga will be described.

  The intake air flow rate (strictly speaking, the amount of air passing through the throttle valve 20 per unit time) is calculated based on the detection value by the air flow sensor 19, but separately from this calculation, a model equation is used in this embodiment. The intake air flow rate is estimated by a model equation based on the intake air flow rate calculated by the air flow sensor 19 (hereinafter referred to as “air flow calculated value”) and described as “model estimated value”. ) Is corrected. Alternatively, the model estimated value is corrected based on the airflow calculated value. These corrections are executed according to the amount of deviation (difference) between the calculated airflow value and the model estimated value.

  The ECU 30 when calculating the airflow calculation value corresponds to “calculation means”, and the ECU 30 when calculating the model estimation value corresponds to “estimation means”, and the model estimation value is based on the airflow calculation value. The ECU 30 when correcting is equivalent to “correction means”.

  The model formula is a calculation formula using a physical quantity correlated with the intake air flow rate other than the air flow sensor 19 as a parameter, and is stored in the microcomputer of the ECU 30. Specific examples of the parameter include a throttle valve opening calculated based on a value detected by the throttle sensor 23, an engine speed calculated based on a value detected by the crank angle sensor 14, and the like.

  Here, the model estimated value is corrected by correcting the model estimated value by the airflow calculated value, but the error of the model estimated value is compensated for. In the first place, the intake flow rate calculated in this way is used to set the target injection amount of fuel. It is. Therefore, since calculation of the intake air flow rate is unnecessary when there is no fuel injection, no error compensation is required, and no calculated airflow value is required.

  Specific examples for controlling not to inject fuel are listed below. That is, when the vehicle driver turns off the ignition switch to stop the engine 10, the fuel injection is stopped. When the engine 10 is idle-stopped with the ignition switch on, fuel injection is stopped. When the vehicle driver is not stepping on the accelerator pedal and the engine speed is slowing down, fuel injection is cut off.

  Focusing on the fact that the calculated airflow is not required when fuel is not injected as described above, the ECU 30 controls the power supply state to the airflow sensor 19 in accordance with the fuel injection control state as shown in the flowchart of FIG. Yes.

  That is, when it is determined in step S10 that fuel injection control is being performed (S10: YES), power supply to the air flow sensor 19 is executed in subsequent step S20. On the other hand, in the case of no fuel injection determined that the fuel injection control is not being performed (S10: NO), the power supply to the air flow sensor 19 is stopped in the subsequent step S30. As a result, energization of the heating resistor 192 and the control circuit is stopped during the fuel injection stop period.

  Here, after the power supply to the air flow sensor 19 is started, that is, after the energization to the heating resistor 192 is started, the temperature of the heating resistor 192 rises to such an extent that the intake flow rate can be accurately calculated. Takes several seconds (preparation time). 4C shows the preparation time T10 in the case of the present embodiment in which the chip type is adopted for the airflow sensor 19, and FIG. 4D shows the preparation time T20 in the case of adopting the bobbin type for the airflow sensor 19. It is a time chart which shows. Incidentally, the bobbin type is a heating resistor and a temperature sensitive resistor formed by forming a heat ray in a bobbin shape.

  Next, one mode when the control of FIG. 3 is executed will be described using the time chart shown in FIG. A solid line L1 in FIG. 4A indicates a model estimated value in a state where error compensation is not performed, and a solid line L2 indicates an actual intake air amount. In addition, a one-dot chain line in FIG. 4A shows how the model estimated value is corrected so as to approach the actual intake air amount by error compensation when the airflow sensor 19 is a chip type, and the two-dot chain line is a bobbin type. In this case, error compensation is shown.

  Then, as shown in FIG. 4B, when the engine 10 is in the fuel injection cut control state, the power supply to the airflow sensor 19 is turned off and the power supply to the airflow sensor 19 is resumed at time t1 when the fuel injection is resumed. Has started. Thereafter, when the preparation times T10 and T20 have elapsed from the time point t1 when the power supply is started, the calculated airflow value can be acquired based on the detected value by the airflow sensor 19. Therefore, the error compensation of the model estimated value is executed from the time when the preparation times T10 and T20 have elapsed, and as a result of executing the error compensation, the model estimated value approaches the actual intake air amount (in FIG. 4A). Dash-dot and two-dot chain).

  In the case of the chip type, since the preparation time is shorter than the bobbin time, the timing for starting the error compensation can be advanced, and as a result, the timing at which the model estimated value almost coincides with the actual intake air amount can be accelerated. In other words, the time required from the time t1 when power supply to the airflow sensor 19 is started until the model estimated value is error-compensated with high accuracy is shorter in the case of the chip type than in the case of the bobbin type (T11, T21).

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) Since energization to the airflow sensor 19 is stopped during the fuel injection stop period in which the calculated airflow value is unnecessary, unnecessary power consumption in the heating resistor 192 and the control circuit can be reduced.

  (2) The chip-type airflow sensor 19 in which the heating resistor 192 is formed in a film shape is adopted, and the film heating resistor 192 is made small so that the heat capacity is smaller than that of the bobbin-like heating resistor. Can be realized easily. Therefore, the preparation time T10 required to rise to a predetermined temperature after the energization of the film heating resistor 192 is started can be made shorter than the preparation time T20 in the case of the bobbin shape. Therefore, since the power supply to the air flow sensor 19 is stopped during the injection stop period while using the chip type air flow sensor, the concern that the target injection amount cannot be set and the desired engine operating state cannot be controlled is reduced. Thus, it is possible to achieve both reduction in power consumption.

  (3) Since the target injection amount is set based on the intake flow rate (model estimated value) estimated by substituting the throttle valve opening and the engine speed into the model formula, the target injection amount can be set even if the preparation time T10 has not elapsed. Can be set.

  (4) By correcting the model formula used for intake flow rate estimation based on the difference between the calculated airflow value and the estimated model value, “the estimated model value is less accurate than the calculated airflow value, so that the desired engine operating state is achieved. It is possible to reduce the concern that it becomes difficult to control with high accuracy. Moreover, a chip type air flow sensor 19 with a short preparation time T10 is employed. Specifically, when the microcomputer of the ECU 30 performs calculation so as to estimate the intake air flow rate using the model formula, the air flow sensor 19 that can make the preparation time T10 shorter than the calculation period (calculation period of the microcomputer) is employed. Therefore, since the error compensation required time T11 can be shortened, the time T11 from when the fuel injection is started until it can be accurately controlled to a desired engine operating state can be shortened.

  (5) In the present embodiment, when the intake flow rate is estimated and updated for each estimation calculation cycle using the model formula, the current estimated value is calculated based on the previously calculated estimated value. And since the chip type airflow sensor 19 is used such that the preparation time T10 is shorter than the estimated calculation cycle, the model formula can be corrected between the previous calculation estimation and the current calculation estimation. . Therefore, it is possible to avoid the preparation time T10 from causing a calculation error of the model formula, and therefore it is possible to improve the estimation accuracy of the intake flow rate by the model formula.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and the characteristic configurations of the embodiments described below may be arbitrarily combined. Moreover, you may implement the said embodiment, changing as follows.

  In the above embodiment, the target fuel injection amount is set based on the model estimated value of the intake flow rate. However, the estimation of the intake flow rate based on the model formula is abolished, and the intake flow rate calculated by the airflow sensor 19 (airflow calculation) The target fuel injection amount may be set based on the value. However, in this case, the target injection amount cannot be set until the preparation time T10 has elapsed.

  In the above embodiment, the chip type air flow sensor 19 is adopted, but a bobbin type air flow sensor may be adopted. However, in this case, it is required to adopt a high-performance bobbin type air flow sensor whose preparation time is several milliseconds.

  In the above embodiment, the chip type airflow sensor 19 is used such that the preparation time T10 is shorter than the estimated calculation cycle. However, the present invention is not limited to such a sensor 19, and the model estimated value It is sufficient that the preparation time T10 can be shortened to such an extent that the above error compensation can be sufficiently performed. For example, a sensor in which the preparation time T10 is increased to several times of the estimated calculation period may be employed.

The figure which shows the outline | summary of the engine system to which the control apparatus of the internal combustion engine concerning one Embodiment of this invention was applied. The figure explaining the structure of the airflow sensor shown in FIG. The flowchart explaining the procedure which controls the electric power supply state to the airflow sensor shown in FIG. The time chart which shows the one aspect | mode at the time of performing control of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 14 ... Crank angle sensor (other sensors), 19 ... Air flow sensor, 23 ... Throttle sensor (other sensors), 24 ... Fuel injection valve, 30 ... ECU (estimating means, calculating means, Correction means), 192... Heating resistor (heater), 193, 194.

Claims (5)

Applied to an internal combustion engine comprising a thermal airflow sensor configured with a heater and a temperature sensing element, and a fuel injection valve for injecting fuel for combustion of the internal combustion engine,
In a control device for an internal combustion engine that sets a target injection amount of fuel using a detection value of the air flow sensor and controls the operation of the fuel injection valve so as to be the target injection amount.
The air flow sensor is configured by forming the heater into a film shape,
A control apparatus for an internal combustion engine, wherein power supply to the air flow sensor is stopped during an injection stop period in which the fuel injection valve is controlled to stop fuel injection. In addition to the air flow sensor, the internal combustion engine includes another sensor that detects a physical quantity correlated with the intake air flow rate.
An estimation means for estimating the intake air flow rate by substituting the detection value by the other sensor into a model equation;
Calculation means for calculating an intake flow rate based on a detection value by the air flow sensor;
A correction unit that sets the target injection amount based on the estimated value by the estimating unit and corrects the model formula based on a difference between the calculated value by the calculating unit and the estimated value;
The control apparatus for an internal combustion engine according to claim 1, comprising:   The airflow sensor is configured so that a preparation time required for the heater temperature to reach a predetermined temperature after the energization of the heater is started is shorter than an estimation calculation cycle by the estimation means. The control apparatus for an internal combustion engine according to claim 2. Applied to an internal combustion engine comprising a thermal airflow sensor configured with a heater and a temperature sensing element, and a fuel injection valve for injecting fuel for combustion of the internal combustion engine,
In a control device for an internal combustion engine that sets a target injection amount of fuel using a detection value of the air flow sensor and controls the operation of the fuel injection valve so as to be the target injection amount.
A control apparatus for an internal combustion engine, wherein power supply to the air flow sensor is stopped during an injection stop period in which the fuel injection valve is controlled to stop fuel injection. A control device for an internal combustion engine according to any one of claims 1 to 4,
At least one of an air flow sensor and a fuel injection valve;
An internal combustion engine control system comprising:

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