JP5276693B2 - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine control device, which is capable of controlling an increase of a matching man-hour while suppressing a control map capacity, and capable of achieving a torque control with high accuracy based on the efficiency of combustion, without depending on various operation conditions and variations including an intake and exhaust VVT. <P>SOLUTION: A torque calculation means performs a torque correction by using the thermal efficiency and the characteristic of a torque curve, which can approximate the relationship between an ignition retard value and a torque generating efficiency by a quadratic function. The torque calculation means includes: calculating a correction coefficient considering an effect of a combustion state change for the change of the intake and exhaust VVT or the like, and an effect on a control operation point; and performing the correction for the change of the intake and exhaust VVT or the like, with respect to the thermal efficiency and torque generating efficiency as well as MBT. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to an internal combustion engine control apparatus that controls an internal combustion engine using an output torque as a control target.

  In recent years, the output shaft torque of an internal combustion engine (hereinafter also referred to as an engine), which is a required value of driving force from the driver or the vehicle, is used as an engine output target value, and the air amount, fuel amount, and ignition as engine control amounts. A control device for an internal combustion engine that achieves good running performance by realizing coordinated control by determining the timing and estimating the actual output torque from the actual operating state of the engine and transmitting it to each of the above vehicle systems is proposed Has been.

For example, a conventional control method for an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 11-501099 (Patent Document 1) is a control method for calculating an output torque of an internal combustion engine as a function of an operating variable, and the engine rotational speed. The output torque is calculated based on the engine load, the mixture composition (air-fuel ratio), the optimum ignition angle (ignition timing), and the exhaust gas return rate (EGR rate).
Specifically, first, the optimum combustion torque is calculated from the characteristic curve group (control map) based on the engine rotation speed and the engine load. Subsequently, the output torque is accurately calculated by correcting the optimum combustion torque based on the actual ignition timing and the EGR rate. Note that the correction amount for correction based on the actual ignition timing and EGR rate is calculated from the control map for each operating point.

  Further, for example, the conventional torque determination method for a gasoline direct injection internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 2000-136749 (Patent Document 2) is a method for calculating an output torque of an internal combustion engine by a model as a function of operating variables. The maximum torque in the standard condition is determined from the predetermined control map based on the operating variable, and the efficiency is given in advance to at least one control variable of the internal combustion engine that adjusts the output torque. Determined as a function of the current value of the control variable and the standard value of this control variable, the maximum torque is corrected with this at least one efficiency to determine the actual output torque.

Also, for example, a control device for an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 2009-13922 (Patent Document 3) is a control method for estimating the thermal efficiency and calculating the output torque of the internal combustion engine, the engine rotation speed, The output torque is calculated based on the engine load, the air-fuel ratio, the EGR rate, and the ignition timing / combustion period.
Specifically, the ignition period is calculated from the ignition timing using the approximate expression based on the linear function, the combustion period is calculated from the change in temperature and pressure in the cylinder, the composition of the working fluid, and the ignition timing. The actual heat efficiency is calculated based on the combustion period.

Japanese National Patent Publication No. 11-501099 JP 2000-136749 A JP 2009-13922 A

  Here, in the conventional control device for an internal combustion engine disclosed in Patent Document 1 or Patent Document 2, the output torque of the internal combustion engine is calculated using a control map corresponding to each operating variable. For this reason, there are problems in that the amount of control maps to be adapted increases, the number of man-hours for adaptation increases, and a large-capacity ROM is required.

  On the other hand, in the conventional control device for an internal combustion engine disclosed in Patent Document 3, the actual heat efficiency based on the ignition timing and the combustion period is used, which is more than the disclosed technique of Patent Document 1 or Patent Document 2. With a small control map, the actual output torque of the internal combustion engine can be calculated with high accuracy.

  However, in the conventional control device for an internal combustion engine disclosed in Patent Document 3, since the ignition timing is calculated from the ignition timing using an approximate expression, the accuracy is approximated when the calculation result including the combustion period is taken into consideration. In order to calculate a combustion period that takes into account all of the state changes, as compared to the actual calculation, a calculation formula is provided for every condition, the condition becomes complicated, the ignition timing and In order to calculate the actual heat efficiency based on the combustion period, there is a problem that a calculation function (CPU) with higher function and accuracy than before is required, and the calculation load (time) also increases.

  Further, although the output torque is influenced by intake and exhaust valve timing (VVT) control, there is a problem that the disclosed technique of Patent Document 3 does not include correction by intake VVT.

  An object of the present invention is to solve the above-described problems, and an object of the present invention is to suppress an increase in the number of man-hours while suppressing a control map capacity, and include intake and exhaust VVT. An object of the present invention is to provide a control device for an internal combustion engine that can perform highly accurate torque control based on combustion efficiency without depending on various operating conditions and variations.

The control apparatus for an internal combustion engine according to the present invention calculates an ignition retard amount from the MBT based on an ignition timing and an MBT in each operation condition of the internal combustion engine, and also calculates the ignition retard amount and each operation of the internal combustion engine. In the control device for an internal combustion engine that calculates the torque generation efficiency from the relationship with the torque generation efficiency under conditions, and corrects the output torque from the torque generation efficiency and the thermal efficiency in each operating state of the internal combustion engine.
An intake VVT control amount calculating means for calculating an intake VVT control amount for controlling an air amount introduced into the cylinder from the intake passage of the internal combustion engine; and an amount of combustion gas discharged from the cylinder to the exhaust passage of the internal combustion engine An exhaust VVT control amount calculating means for calculating an exhaust VVT control amount for controlling the engine, and a basic MBT calculating means for calculating a basic MBT based on an intake air flow rate charging efficiency and an engine speed in a standard operating state of the internal combustion engine; A relationship between the intake VVT control amount and the MBT, and a first VVT correction coefficient calculating means for calculating a first VVT correction coefficient using a characteristic that the MBT varies depending on the intake VVT control amount and the exhaust VVT control amount. Calculated from the engine speed using a characteristic of moving along the intake VVT control amount according to a change in the engine speed. A second VVT correction coefficient calculating means for calculating a correction coefficient for the shift amount, and a relationship between the intake VVT control amount and the MBT using characteristics in which the slope of the MBT changes with a change in the intake air flow rate charging efficiency. A third VVT correction coefficient calculating means for calculating a correction coefficient for a gain amount calculated from the intake air flow rate charging efficiency, and the relationship between the intake VVT control amount and the MBT is determined by the change in the exhaust VVT control amount. A correction coefficient for an offset amount calculated from the exhaust VVT control amount and the engine rotation speed is calculated using the characteristic that the region of the intake VVT control amount in which the MBT is constant along the direction of and 4VVT correction coefficient calculating means, the basic MBT corrected based from the first to the correction coefficient calculated at the 4 VVT correction coefficient calculating means, And MBT calculating means for calculating the serial MBT, is characterized in that it comprises a.

  The present invention relates to combustion in response to changes in intake VVT, exhaust VVT, etc., in a torque calculation means for performing torque correction using a characteristic of a torque curve that can approximate the relationship between an ignition retard amount and torque generation efficiency by a quadratic function and thermal efficiency. A correction coefficient is calculated in consideration of the influence of the state change and the influence on the control operating point, and correction is made for changes in the intake VVT, exhaust VVT, etc. with respect to the thermal efficiency, torque generation efficiency, and MBT. Can be suppressed, and high-accuracy torque control based on combustion efficiency independent of various operating conditions and variations can be performed.

1 is a schematic configuration diagram showing an intake system of an internal combustion engine according to Embodiment 1 of the present invention. It is a block diagram which shows roughly the structure of the engine control part which concerns on Embodiment 1 of this invention. FIG. 3 is a block diagram specifically illustrating functions related to intake air flow rate control, thermal efficiency calculation, estimated torque calculation, and other calculations of the ECU according to Embodiment 1 of the present invention. It is a flowchart which shows the calculation process of the estimated torque which concerns on Embodiment 1 of this invention. It is a flowchart which shows the control processing of the intake air flow rate which concerns on Embodiment 1 of this invention. It is a control block diagram which shows concretely the calculation process of the actual heat efficiency calculation which concerns on Embodiment 1 of this invention. It is a characteristic view with respect to the ignition timing of the engine torque according to Embodiment 1 of the present invention. It is a block diagram which shows concretely calculation of the VVT correction coefficient with respect to MBT which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship of the intake VVT opening degree, rotational speed, intake air flow rate filling efficiency, and exhaust VVT opening degree with respect to MBT which concerns on Embodiment 1 of this invention. It is a block diagram which shows concretely calculation of the VVT correction coefficient with respect to the thermal efficiency which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship of the exhaust VVT opening degree with respect to the thermal efficiency which concerns on Embodiment 1 of this invention.

  Preferred embodiments of a control apparatus for an internal combustion engine according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and includes various design changes.

Embodiment 1 FIG.
1 is a schematic configuration diagram showing an intake system of an internal combustion engine according to Embodiment 1 of the present invention. In FIG. 1, a crank angle sensor 2 that generates an electric signal corresponding to the rotation angle is attached to the crank of the engine 1. An intake pipe 3 that forms an intake passage is connected to the intake port of the combustion chamber of the engine 1.

  On the upstream side of the intake pipe 3 (opposite side of the engine 1), an air cleaner 4 for purifying the taken outside air is attached. On the downstream side of the air cleaner 4 (engine 1 side) of the intake pipe 3, an air flow sensor 5 that generates an electric signal corresponding to the intake air flow rate, and an intake that generates an electric signal corresponding to the intake air temperature in the intake pipe 3. An air temperature sensor (intake air temperature sensor) 6 is provided integrally or separately. FIG. 1 shows an example in which both sensors 5 and 6 are integrally formed.

  A throttle valve 7 for adjusting the amount of air sent to the engine 1 is provided on the intake pipe 3 downstream of the air flow sensor 5 and the intake air temperature sensor 6. A throttle position sensor 8 that generates an electrical signal corresponding to the throttle opening is connected to the throttle valve 7.

  A surge tank 9 for eliminating intake pulsation is provided on the downstream side of the throttle valve 7 of the intake pipe 3. The surge tank 9 is provided with an intake manifold pressure sensor 10 that generates an electrical signal corresponding to the air pressure in the surge tank 9. Note that both the air flow sensor 5 and the intake manifold pressure sensor 10 may be provided, or only one of them may be provided. Further, instead of the intake manifold pressure sensor 10 that directly measures the intake manifold pressure, a means for estimating the intake manifold pressure from other sensor information may be used.

  The surge tank 9 is electronically controlled to open and close an EGR pipe 12 communicating with the exhaust pipe 11 of the engine 1 to adjust the introduction amount for recirculation of exhaust gas introduced into the intake pipe 3. A valve 13 is connected. In the intake pipe 3, an injector 14 for injecting fuel is provided on the engine 1 side downstream of the surge tank 9. The injector 14 may be provided so as to inject fuel directly into the cylinder 15.

  At the top of the cylinder 15, a spark plug 16 that ignites a combustible mixture generated by mixing the air sucked into the engine 1 and the fuel injected from the injector 14, and for sparking the spark plug 16. An ignition coil 17 for generating a current is provided. An intake valve 18 for adjusting the amount of air introduced from the intake pipe 3 into the cylinder 15 and an exhaust valve 19 for adjusting the amount of air discharged from the cylinder 15 to the exhaust pipe 11 of the engine 1 are provided. .

  FIG. 2 is a block diagram schematically showing the configuration of the control unit of the engine 1. In FIG. 2, an electronic control unit (hereinafter referred to as an ECU) 100 includes a crank angle sensor 2, an air flow sensor 5, an intake air temperature sensor 6, a throttle position sensor 8, an intake manifold pressure sensor 10, and an air-fuel ratio sensor 20. The electrical signal generated by is received.

  The ECU 100 also receives electrical signals from an atmospheric pressure sensor (not shown) that generates an electrical signal corresponding to the atmospheric pressure, and various sensors other than the sensors 2, 5, 6, 8, 10, and 20. Receive. These various sensors include an accelerator position sensor (not shown) for generating an electric signal corresponding to the operation amount of an accelerator (not shown), a combustion control sensor for the engine 1 and a vehicle behavior control sensor ( For example, a vehicle speed sensor, a water temperature sensor, etc.) are included.

  The ECU 100 detects the rotational speed Ne from the crank angle sensor 2, the actual intake air flow rate Qr from the air flow sensor 5, the intake air temperature AT from the intake air temperature sensor 6, the throttle opening TH from the throttle position sensor 8, and the intake manifold pressure sensor. Input data such as the intake manifold pressure PB from the air-fuel ratio 10, the air-fuel ratio AF from the air-fuel ratio sensor 20, and the accelerator opening D (not shown) for detecting the accelerator opening provided in the vehicle. On the basis of the input torque from the sensors 2, 5, 6, 8, 10, 20 and other controllers (for example, transmission) Control, brake control, traction control, stability control, etc.) It calculates the target output torque TRQt.

Further, the ECU 100 refers to each control target value such as the EGR rate R, the air-fuel ratio AF, the intake VVT opening Vin, the exhaust VVT opening Vex, and the ignition timing IT so as to achieve the target output torque TRQt. The throttle valve 7 is controlled to achieve the target value of the target intake air flow rate Qt, the EGR valve 13 is controlled to achieve the target value of the EGR rate R, and the target value of the intake VVT opening Vin is achieved. Then, the intake valve 18 is controlled, the exhaust valve 19 is controlled so as to achieve the target value of the exhaust VVT opening Vex, the injector 14 is driven so as to achieve the target value of the air-fuel ratio AF, and the target of the ignition timing IT is set. The ignition coil 17 is energized to achieve the value. ECU 100 also calculates target values for actuators other than these actuators.

  Here, ECU 100 is a microprocessor (not shown) having a CPU that executes arithmetic processing, a ROM that stores program data and fixed value data, and a RAM that can be rewritten sequentially by updating the stored data. It is configured.

  FIG. 3 is a block configuration diagram specifically showing the inside of the ECU 100. The ECU 100 functionally includes intake air flow rate control means, estimated torque calculation means, torque generation efficiency calculation means, and thermal efficiency calculation means as main constituent means, as will be described later.

  In the ROM of the ECU 100, the air-fuel ratio control means 110, the EGR valve opening degree control means 111, the EGR rate calculation means 112, the intake VVT control means 113, the exhaust VVT control means 114, the torque generation efficiency calculation means 115, and the estimated torque calculation means 116 The ignition timing control means 117 and the intake air flow rate control means 118 are stored as software.

  The intake air flow rate control means 118 includes throttle opening control means 119, required torque calculation means 120, target torque calculation means 121, target cylinder fresh air amount calculation means 122, target intake air flow rate calculation means 123, and thermal efficiency. The calculation means 124 is stored as software.

  The torque generation efficiency calculation means 115 calculates MBT (abbreviation of Minimum Spark Advance for Best Torque, which means an ignition timing at which the throttle opening and the engine speed are constant and the torque is maximum). The MBT calculating means 125 for performing the reduction and the decreasing rate calculating means 126 for calculating the decreasing rate of the thermal efficiency are stored as software.

  The air-fuel ratio control means 110 drives the injector 14 to change the amount of fuel supplied to the engine 1 and controls the air-fuel ratio AF of the combustible mixture. Further, the EGR valve opening degree control means 111 controls the opening degree of the EGR valve 13 according to the operating state such as the actual intake air flow rate Qr and the rotational speed Ne of the engine 1. Further, the EGR rate calculating means 112 calculates an EGR rate R indicating an exhaust gas introduction rate based on the operating state such as the actual intake air flow rate Qr and the rotational speed Ne of the engine 1 and the opening degree of the EGR valve 13, for example. calculate.

  The intake VVT control means 113 calculates an intake VVT control amount according to the operating state, and controls the opening of the intake valve 18 that adjusts the amount of air introduced from the intake pipe 3 into the cylinder 15. Further, the exhaust VVT control means 114 calculates an exhaust VVT control amount according to the operating state, and controls the opening of the exhaust valve 19 that adjusts the combustion gas discharged from the cylinder 15 to the exhaust pipe 11.

The torque generation efficiency calculating means 115 is an intake air flow rate charging efficiency calculated from the air-fuel ratio AF, the EGR rate R, the intake VVT opening Vin, the exhaust VVT opening Vex, the ignition timing IT, the actual intake air flow rate Qr, or the intake manifold pressure PB. (Hereinafter referred to as charging efficiency.) The torque generation efficiency of the engine 1 is calculated based on Ec and the rotational speed Ne.

  The thermal efficiency calculating means 124 is based on the air-fuel ratio AF, the EGR rate R, the intake VVT opening Vin, the exhaust VVT opening Vex, the charging efficiency Ec calculated from the actual intake air flow rate Qr or the intake manifold pressure PB, and the rotational speed Ne. Then, the thermal efficiency η of the engine 1 is calculated. Then, the actual thermal efficiency ηi is calculated from the torque generation efficiency and the thermal efficiency η.

  Estimated torque calculation means 116 is generated from engine 1 based on air-fuel ratio AF, charging efficiency Ec calculated from actual intake air flow rate Qr or intake manifold pressure PB, and actual thermal efficiency ηi (= torque generation efficiency × thermal efficiency η). A calculation for estimating the actual torque, that is, the estimated output torque TRQ of the engine 1 or the estimated indicated mean effective pressure Pir is calculated.

The ignition timing control means 117 controls the ignition timing IT of the engine 1 by energizing the ignition coil 17. Further, the throttle opening degree control means 119 variably controls the actual intake air flow rate Qr by changing the opening area of the intake pipe 3 by controlling the throttle opening degree TH of the throttle valve 7. Further, the required torque calculation means 120 calculates the driver required output torque TRQd by the driver of the vehicle based on, for example, the rotational speed Ne of the engine 1 (or the travel speed Vs of the vehicle) and the accelerator opening D.

  The target torque calculation means 121 calculates the target output torque TRQt or the target indicated mean effective pressure Pit that should be generated by the engine 1 based on the driver request output torque TRQd. Further, the target cylinder fresh air amount calculating means 122 calculates the target cylinder interior based on the target output torque TRQt or the target indicated mean effective pressure Pit, the actual thermal efficiency ηi (= torque generation efficiency × thermal efficiency η), and the air-fuel ratio AF. A fresh air amount Qct is calculated. Further, the target intake air flow rate calculation means 123 calculates a target intake air flow rate Qt that the engine 1 should inhale based on the target cylinder fresh air amount Qct. The intake air flow rate control means 118 controls the throttle opening TH through the throttle opening degree control means 119 so that the actual intake air flow rate Qr matches the target intake air flow rate Qt.

Hereinafter, the calculation process of the estimated output torque TRQ by the estimated torque calculation unit 116 according to the first embodiment will be described more specifically with reference to FIG. 4 together with FIGS. FIG. 4 is a flowchart showing the estimated torque calculation process.
First, the air flow sensor 5 or the intake manifold pressure sensor 10 detects the actual intake air flow rate Qr sucked into the engine 1 or the intake manifold pressure PB in the surge tank 9 (step S101).

  Subsequently, the estimated torque calculating means 116 performs a filtering process on the actual intake air flow rate Qr or estimates the density in the cylinder 15 from the intake manifold pressure PB, so that the fresh air in the actual cylinder per one stroke is obtained. A quantity Qcr [g] is calculated (step S102).

  Next, the air-fuel ratio sensor 20 detects the air-fuel ratio AF of the combustible mixture (step S103). Note that the air-fuel ratio AF may be an actual detection value detected by the air-fuel ratio sensor 20, or may be obtained from a target value of the air-fuel ratio AF used for calculating the drive time of the injector 14.

Subsequently, the estimated torque calculation means 116 calculates the fuel amount Qf [g] per stroke as shown in the following equation (1) based on the actual fresh air amount Qcr in the cylinder and the air-fuel ratio AF. Calculate (step S104).
Qf = Qcr / AF (1)

  Further, the estimated torque calculation means 116 calculates the heat generation amount from the fuel amount Qf per stroke based on the heat generation amount of the fuel used in the engine 1 (for example, about 44 [MJ / kg] in the case of gasoline). Ht [J] is calculated (step S105).

  Next, the torque generation efficiency calculation unit 115 calculates the torque generation efficiency [%] of the engine 1, and the thermal efficiency calculation unit 124 calculates the thermal efficiency η [%] of the engine 1. Then, the actual thermal efficiency ηi is calculated from the torque generation efficiency and the thermal efficiency η (step S106). The calculation process of the torque generation efficiency, the thermal efficiency η, and the actual thermal efficiency ηi will be described later.

Subsequently, the estimated torque calculation means 116 performs the actual illustrated work Wi, which is the work that the combustion gas performs on the piston in the cylinder 15, as shown in the following equation (2), based on the calorific value Ht and the actual thermal efficiency ηi. [J] is calculated (step S107).
Wi = Ht × ηi (2)

Next, the estimated torque calculation means 116 calculates the estimated indicated average effective pressure Pir [kPa] as shown in the following equation (3) based on the actual indicated work Wi (step S108).
Pir = Wi / Vc (3)
In Expression (3), Vc [L] indicates the cylinder stroke volume per cylinder.

Subsequently, the estimated torque calculating means 116 calculates the estimated output torque TRQ [Nm] as shown in the following equation (4) based on the estimated indicated average effective pressure Pir (step S109).
TRQ = Pir × Vc × z / (2π × i) (4)
In equation (4), z represents the number of cylinders, and i represents the rotational speed per cycle (for example, i = 2 in the case of a 4-cycle engine).

  Thus, the estimated output torque TRQ can be calculated with high accuracy by using the actual thermal efficiency ηi.

Next, calculation processing of intake air flow rate control in the intake air flow rate control means 118 according to Embodiment 1 will be described with reference to FIG. 5 together with FIGS. FIG. 5 is a flowchart of intake air flow rate control.
First, the crank angle sensor 2 detects the rotational speed Ne of the engine 1, and the accelerator opening sensor (not shown) detects the accelerator opening D (step S201). Note that the detected value may be used as the rotational speed Ne of the engine 1. At this time, instead of the crank angle sensor 2 detecting the rotational speed Ne of the engine 1, a vehicle speed sensor (not shown) may detect the traveling speed Vs of the vehicle.

  Subsequently, the required torque calculation means 120 uses a driver required output torque map in which the relationship between the rotational speed Ne (or travel speed Vs) of the engine 1, the accelerator opening D and the driver required output torque TRQd is described. Then, the driver request output torque TRQd is calculated from the rotational speed Ne (or travel speed Vs) of the engine 1 and the accelerator opening D (step S202).

  Next, each torque request value is input from another controller (for example, transmission control, brake control, traction control, etc.) (step S203).

  Subsequently, the intake air flow rate control means 118 compares the driver request output torque TRQd with the torque request value to calculate the final request output torque (step S204). The final required output torque calculated here indicates the torque output from the crankshaft of the engine 1.

  Next, the intake air flow rate control means 118 calculates loads such as an alternator generally called an engine accessory, an air conditioner compressor, a power steering pump, a transmission pump, and a torque converter (step S205).

  Subsequently, the intake air flow rate control means 118 adds the final required output torque and the engine auxiliary load, and calculates the engine required output torque considering the auxiliary load associated with the engine 1 (step S206).

  Next, the intake air flow rate control means 118 calculates mechanical loss and pumping loss (collectively referred to as engine loss) possessed by the engine 1 (step S207).

  Subsequently, the target torque calculating means 121 adds the engine required output torque and the engine loss to calculate the target indicated average effective pressure Pit that should be generated in the cylinder 15 of the engine 1 (step S208). Note that the target torque calculation unit 121 may calculate the target output torque TRQt instead of the target indicated average effective pressure Pit.

  Next, the torque generation efficiency calculation means 115 calculates the torque generation efficiency of the engine 1, the thermal efficiency calculation means 124 calculates the thermal efficiency η of the engine 1, calculates the actual thermal efficiency ηi from the torque generation efficiency and the thermal efficiency η, The air-fuel ratio sensor 20 detects the air-fuel ratio AF of the combustible mixture (step S209). The actual thermal efficiency ηi may be a detected value described later, and the air-fuel ratio AF may be the detected value described above.

Subsequently, the target in-cylinder fresh air amount calculation means 122 calculates the target in-cylinder fresh air amount Qct for realizing the target indicated average effective pressure Pit based on the target indicated average effective pressure Pit, the actual thermal efficiency ηi, and the air-fuel ratio AF. Is calculated (step S210). Here, the target cylinder fresh air amount Qct is expressed by the following equation (5) by back-calculating the above-described equations (1) to (3).
Qct = AF × Qf
= AF × Ht / 44000
= AF × Wi / (η × 44000)
= AF × Pit × Vc / (η × 44000) (5)

  Next, the target intake air flow rate calculation means 123 calculates a target intake air flow rate Qt [g / s] that should be taken in by the engine 1 based on the target cylinder fresh air amount Qct and the rotational speed Ne (step). S211).

  Subsequently, the intake air flow rate control means 118 calculates the target value of the throttle opening TH so that the actual intake air flow rate Qr matches the target intake air flow rate Qt, and the throttle opening degree control means 119 is used to open the throttle. The degree TH is controlled (step S212). In this case, the target intake air flow rate Qt can be achieved with high accuracy by using at least one of the orifice flow rate calculation formula and the throttle opening feedback using the air flow sensor 5.

  By controlling the intake air flow rate in this way, the driver request output torque TRQd and the torque request value from another controller can be achieved with high accuracy.

  Subsequently, thermal efficiency will be described below. In general, the thermodynamic cycle of an internal combustion engine is roughly divided into an Otto cycle and a diesel cycle, a gasoline engine is approximated to an Otto cycle, and a diesel engine is often approximated to a diesel cycle. When calculating the thermal efficiency from these cycles, the working fluid is a perfect gas (ideal gas) with the specific heat of air at ambient temperature, and combustion is performed instantaneously at top dead center It is common to think as

  In this case, it is known that the thermal efficiency in the Otto cycle is determined only by the specific heat ratio κ of the working fluid and the compression ratio ε of the engine. That is, in the theoretical air cycle, if the specific heat ratio κ of the working fluid and the compression ratio ε of the engine do not change, the thermal efficiency becomes a constant value in any operating state.

However, in the actual engine cycle, it is known that the following four points are different from the theoretical air cycle.
First, as a first point, since combustion is performed under high temperature and high pressure, thermal dissociation occurs. As a second point, since combustion is performed during the stroke, the composition of the working fluid differs between the compression stroke and the expansion stroke. As a third point, the specific heat changes because the composition and temperature of the working fluid change. Further, as a fourth point, combustion is not performed instantaneously and continues for a certain period.

  Therefore, when calculating the actual thermal efficiency ηi, it is necessary to consider the above four points. However, as described above, for the combustion period as the fourth point, in order to take into account all the state changes, as described above. Since the condition becomes complicated, the influence of the fourth point is included in other correction terms, so that only the first to third points are considered.

  Next, calculation processing of the thermal efficiency η according to the first embodiment will be briefly described based on the above-described description with reference to FIGS.

First, the charging efficiency Ec [%] and the rotational speed Ne of the engine 1 are calculated. The charging efficiency Ec is calculated by executing a filtering process on the actual intake air flow rate Qr, or estimating the density in the cylinder 15 from the intake manifold pressure PB. g] and the mass Qco [g] with respect to the cylinder stroke volume Vc of air in the standard state, the following equation (6) is calculated.
Ec = Qcr / Qco (6)

Here, the thermal dissociation caused by the combustion depends on the temperature and pressure at the time of combustion, and these are considered to have a strong correlation with the charging efficiency Ec. Therefore, hereinafter, the thermal efficiency in consideration of thermal dissociation shown in the first point is referred to as basic thermal efficiency ηb [%].
First, the thermal efficiency calculation means 124 calculates the basic thermal efficiency ηb from the charging efficiency Ec and the rotational speed Ne of the engine 1 using the basic thermal efficiency map in which the relationship between the charging efficiency Ec and the basic thermal efficiency ηb is described.

Next, the influence on the thermal efficiency by the second point and the third point will be considered.
Since these two points are caused by the composition of the working fluid and the change of the composition, it is considered that the basic thermal efficiency ηb may be corrected according to the composition of the working fluid. Here, as physical quantities indicating the composition of the working fluid, for example, air-fuel ratio AF, EGR rate R, intake VVT opening Vin, exhaust VVT opening Vex, and the like are conceivable. Therefore, the basic thermal efficiency ηb is corrected based on each physical quantity indicating the composition of the working fluid.

  Specifically, each physical quantity indicating the composition of the working fluid mentioned above as an example will be described. The air-fuel ratio sensor 20 detects the air-fuel ratio AF of the combustible mixture, and the EGR rate calculation means 112 calculates the EGR rate R. Then, the intake VVT control means 113 and the exhaust VVT control means 114 calculate the intake VVT opening Vin and the exhaust VVT opening Vex, respectively.

  Note that the air-fuel ratio AF may be obtained from the target value as described above. For the EGR rate R, the external EGR amount introduced via the EGR valve 13 and the internal EGR amount that is the combustion gas remaining in the cylinder 15 during the gas exchange from the exhaust stroke to the intake stroke are added. The total EGR amount is calculated and is calculated based on the total EGR amount, and the case where the EGR amount is calculated only from the external EGR amount.

  For the external EGR amount, for example, an external EGR amount map in which the operation state such as the rotational speed Ne of the engine 1 and the charging efficiency Ec, the relationship between the opening degree of the EGR valve 13 and the external EGR amount is recorded is stored in the ROM in advance. The external EGR amount map may be searched with the current operation state. Similarly, for the internal EGR amount, for example, an internal EGR amount map in which the operating state such as the rotational speed Ne of the engine 1 and the charging efficiency Ec and the relationship between the VVT and the internal EGR amount is recorded is stored in the ROM in advance. What is necessary is just to search an internal EGR amount map by the driving | running state at the present time.

  As another method for calculating the external EGR amount, the fresh air partial pressure in the surge tank 9 estimated from the actual intake air flow rate Qr detected by the airflow sensor 5 and the intake manifold pressure PB detected by the intake manifold pressure sensor 10 are used. The amount of external EGR may be estimated from the above. As another method, the external EGR amount may be calculated in advance from the exhaust pressure (pressure in the exhaust pipe 11), the intake manifold pressure PB, and the opening degree of the EGR valve 13 using an orifice flow rate calculation formula.

  When only the external EGR amount is used for the EGR rate R, the intake VVT opening Vin and the exhaust VVT opening Vex are calculated based on the intake VVT control amount and the exhaust VVT control amount calculated according to the operating state. .

  Next, the thermal efficiency calculating means 124 calculates a correction coefficient for each physical quantity using a map or the like in which the relationship between each physical quantity indicating the composition of the air-fuel working fluid and the thermal efficiency is described. Then, the corrected thermal efficiency ηr [%] is calculated using the basic thermal efficiency ηb and the correction coefficient for each physical quantity.

  Here, although the water temperature is not included as a physical quantity indicating the composition of the working fluid, the water temperature WT is first detected and the relationship with the thermal efficiency is described, as with each physical quantity indicating the composition of the air-fuel working fluid. The correction coefficient may be calculated using the map or the like, and further corrected to the corrected thermal efficiency ηr [%].

  Subsequently, the MBT calculation means 125 in the torque generation efficiency calculation means 115 for calculating θm that is the MBT according to the first embodiment will be briefly described based on a known technique. Similar to the concept of the thermal efficiency calculation unit 124 described above, first, the MBT calculation unit 125 uses the basic MBT map in which the relationship between the charging efficiency Ec and the MBT is described, from the charging efficiency Ec and the rotational speed Ne, to determine the basic MBT. Θmb is calculated.

  Next, in the same way as the idea in the thermal efficiency calculating means 124 described above, each of the physical quantities (including the water temperature) indicating the composition of the air-fuel working fluid and a map in which the relationship between the MBT is described is used. A correction coefficient for the physical quantity is calculated.

  Next, θmr, which is the corrected MBT, is calculated using θmb, which is the basic MBT, and the correction coefficient for each physical quantity, and is set as θm, which is the MBT.

  Next, the reduction rate calculation unit 126 that calculates the thermal efficiency reduction rate A in the torque generation efficiency calculation unit 115 according to Embodiment 1 will be briefly described based on a known technique. It is well known that the relationship between the thermal efficiency and the ignition timing decreases with a characteristic that approximates a quadratic function regardless of whether the angle is advanced or retarded by maximizing the thermal efficiency during MBT. Therefore, the reduction rate is calculated by approximating the reduction rate as the slope of the quadratic function. Similar to the concept of the thermal efficiency calculation means 124 and the MBT calculation means 125 described above, the basic reduction rate Ab and the corrected reduction rate are based on the respective physical quantities (including the water temperature) indicating the composition of the air-fuel working fluid. Ar may be calculated.

Next, the calculation process of the actual thermal efficiency ηi will be described with reference to the flowchart of FIG. First, the ignition timing IT is calculated (step S301). In the first place, the torque characteristic of the engine 1 can be approximated as a quadratic function with respect to the ignition timing IT as shown in FIG. Specifically, the retard amount θr is calculated as in the following equation (7) based on θm (step S302), which is the MBT calculated from the above, and the ignition timing IT (step S303).
θr = θm−IT (7)

Next, the torque generation efficiency is calculated using the characteristics of the torque curve that can approximate the relationship between the retard amount θr and the torque generation efficiency indicating the torque amount by a quadratic function. Specifically, the torque generation efficiency normalized with respect to the torque amount from the retard amount θr as in the following equation (8) based on the characteristic of the torque curve that is a quadratic function with the decrease rate A as the slope. K is calculated (step S305). At this time, instead of the torque generation efficiency K, an absolute torque amount such as the engine torque T may be calculated.
K = 1−Ar × θr × θr (8)

Next, based on the torque generation efficiency K and the thermal efficiency η (step S306) calculated as described above, the actual thermal efficiency ηi is calculated as in the following equation (9) (step S307).
ηi = η × K (9)

  Thus, the actual thermal efficiency ηi is calculated from θm, which is MBT, the ignition timing IT, the decrease rate A, and the thermal efficiency η.

  Next, referring to FIG. 8 together with FIG. 1 to FIG. 3, FIG. 6, and FIG. 7, the first to fourth of the MBT of the MBT calculation means 125 in the torque generation efficiency calculation means 115 according to the first embodiment. The calculation of the VVT correction coefficient will be described. The relationship between the intake VVT opening Vin and MBT shown in FIG. 9 will be described using characteristics that vary depending on the rotational speed Ne, the charging efficiency Ec, or the exhaust VVT opening Vex.

First, FIG. 9 is a diagram showing the relationship among the intake VVT opening Vin, the rotational speed Ne, the charging efficiency Ec, and the exhaust VVT opening Vex with respect to MBT, which is derived by verifying actual machine data. The relationship between the intake VVT opening Vin and MBT is shown with respect to the most advanced angle (0 deg) of the exhaust VVT opening (upper left figure). When the rotational speed Ne increases with respect to the upper left figure, the intake VVT is increased. The characteristic of the opening degree Vin is shifted to the right side along the region of the intake VVT opening degree Vin where the MBT is constant (upper right diagram). In other words, the change in the rotational speed Ne, it can be said that the characteristics of MBT is moved in the direction of the control amount of the intake VVT opening Vin along the region of the intake VVT opening Vin becomes constant. Further, when the filling efficiency Ec is increased with respect to the upper left figure, the slope of the MBT characteristic becomes smaller (lower left figure). That is, it can be said that the MBT slope changes with the change in the filling efficiency Ec. Further, when the rotational speed Ne and the charging efficiency Ec increase with respect to the upper left figure, the characteristics of the intake VVT opening Vin are shifted to the right along the region of the intake VVT opening Vin where the MBT is constant, and the inclination of the MBT Becomes smaller (lower right figure). Further, as the exhaust VVT opening Vex advances toward the retard side, the MBT offset increases with respect to the most advanced angle (0 deg) of the exhaust VVT opening (middle lower diagram). That is, it can be said that the characteristic moves along the MBT direction and the control amount direction of the intake VVT opening Vin according to a change in the control amount of the exhaust VVT opening Vex.

  For the MBT calculating means 125 in the torque generation efficiency calculating means 115, the intake VVT opening Vin and the exhaust VVT opening Vex are calculated (step S401), and the relationship between the intake VVT opening Vin and the exhaust VVT opening Vex is described. The first VVT correction coefficient KBvvt2 is calculated from the obtained map (step S402).

  Then, the rotational speed Ne and the charging efficiency Ec are calculated (step S403), and the second VVT correction coefficient KSvvt2 is calculated from the correction map describing the relationship between the rotational speed Ne (step S404).

  Then, the first VVT correction coefficient KBvvt2 calculated in step S402 and the second VVT correction coefficient KSvvt2 are added to perform 0 clip treatment (correction value is only a positive value) (step S405).

  Further, a third VVT correction coefficient KOvvt2 is calculated from a correction map describing the relationship between the exhaust VVT opening degree Vex and the rotational speed Ne (step S406). Further, the fourth VVT correction coefficient KGvvt2 is calculated from the correction map describing the relationship with the charging efficiency Ec (step S407).

Then, the first 3VVT correction coefficient KOvvt2 calculated in step S406, based on a first 4VVT correction coefficient KGvvt2 calculated in step S407, calculates a VVT correction coefficient Kvvt1 against the MBT by the following equation (10) ( Step S408).
Kvvt1 = {max (KBvvt2 + KSvvt2) + KOvvt2}
× KGvvt2 (10)

Next, calculate the θmb a basic MBT (step S409), by correcting at VVT correction coefficient Kvvt1 against the MBT, is calculated which is corrected MBT θmr (step S410).

  As described above, the first VVT correction coefficient KBvvt2 calculated from the map in which the relationship between the intake VVT opening Vin and the exhaust VVT opening Vex is described, and the second VVT correction calculated from the correction map in which the relationship between the rotational speed Ne is described. The fourth VVT correction coefficient KGvvt2 calculated from the correction map describing the relationship between the coefficient KSvvt2, the relationship between the exhaust VVT opening Vex and the rotational speed Ne, calculated from the third VVT correction coefficient KOvvt2, and the charging efficiency Ec. Based on the above, a VVT correction coefficient Kvvt1 for MBT is calculated, θmb that is the basic MBT is corrected, and θmr that is the corrected MBT is calculated.

  Then, the torque generation efficiency K is calculated from the corrected MBT θmr, the above-described decrease rate A, and the ignition timing IT, and the actual heat efficiency ηi is calculated from the thermal efficiency η, while the control map capacity is suppressed, and the intake VVT opening Vin, It can be calculated with high accuracy without depending on various operating conditions and variations such as the exhaust VVT opening Vex, the related charging efficiency Ec, and the rotational speed Ne.

  The first VVT correction coefficient KBvvt2, the second VVT correction coefficient KSvvt2, the third VVT correction coefficient KOvvt2, and the fourth VVT correction coefficient KGvvt2 are set by strict measurement under various operating conditions, or the tool is considered in consideration of man-hours. What is necessary is just to set using the numerical result of the engine simulation in the calculation using etc.

  Next, calculation of the VVT correction coefficient for the thermal efficiency of the thermal efficiency calculation unit 124 according to the first embodiment will be described with reference to FIG. 10 together with FIGS. 1 to 3 and FIGS. 6 and 7. The relationship between the exhaust VVT opening degree Vex and the thermal efficiency shown in FIG. 11 will be described using characteristics that can be approximated by a quadratic function.

  First, FIG. 11 is a diagram showing the relationship of the exhaust VVT opening degree Vex with respect to the thermal efficiency η derived by verifying actual machine data. Specifically, the characteristic can be approximated by a quadratic function.

  Regarding the calculation of the VVT correction coefficient for the thermal efficiency of the thermal efficiency calculation means 124, the intake VVT opening Vin and the exhaust VVT opening Vex are calculated (step S401). Further, the rotational speed Ne and the charging efficiency Ec are calculated (step S403).

  Then, a fifth VVT correction coefficient A is calculated from an inclination map in which the relationship between the charging efficiency Ec and the rotational speed Ne with respect to the square of the exhaust VVT opening degree Vex is described (step S421).

  Then, a sixth VVT correction coefficient B is calculated from an inclination map in which the relationship between the charging efficiency Ec and the rotational speed Ne with respect to the exhaust VVT opening degree Vex is described (step S422).

  Further, a seventh VVT correction coefficient C is calculated from an offset map in which the relationship between the charging efficiency Ec and the rotational speed Ne with respect to the intake VVT opening degree Vin is described (step S423).

Then, the exhaust VVT opening degree Vex calculated in step S401, the fifth VVT correction coefficient A calculated from the inclination map in step S421, the sixth VVT correction coefficient B calculated from the inclination map in step S422, and the offset in step S423. Based on the seventh VVT correction coefficient C calculated from the map, a VVT correction coefficient Kvvt2 for the thermal efficiency representing the slope and offset of the quadratic function is calculated as in the following equation (11) (step S424).
Kvvt2 = A × Vex × Vex + B × Vex + C (11)

  Next, ηb, which is the basic thermal efficiency, is calculated (step S425), corrected with the VVT correction coefficient Kvvt2 for the thermal efficiency, and ηr of the corrected thermal efficiency is calculated (step S426).

  (Delete)

  As described above, the fifth VVT correction coefficient A calculated from the inclination map in which the relationship between the charging efficiency Ec and the rotational speed Ne is described, the sixth VVT correction coefficient B calculated from the inclination map, and the seventh VVT correction coefficient calculated from the offset map. Based on C, the VVT correction coefficient Kvvt2 for the thermal efficiency is calculated, the basic thermal efficiency ηb is corrected, and the corrected thermal efficiency ηr is calculated.

  Then, the torque generation efficiency K is calculated from the above-mentioned MBT θm, the decrease rate A, and the ignition timing IT, the actual heat efficiency ηi is calculated from the corrected thermal efficiency ηr, and the intake map VVT opening Vin, It can be calculated with high accuracy without depending on various operating conditions and variations such as the exhaust VVT opening Vex, the related charging efficiency Ec, and the rotational speed Ne.

  Whether the fifth VVT correction coefficient A calculated from the inclination map, the sixth VVT correction coefficient B calculated from the inclination map, and the seventh VVT correction coefficient C calculated from the offset map are set by strict measurement under various operating conditions. Alternatively, it may be set using the numerical result of the engine simulation in the calculation using a tool or the like in consideration of the man-hour.

  As described above, the estimated torque calculation means 116 calculates the estimated output torque TRQ with high accuracy based on the actual thermal efficiency ηi. Here, the actual thermal efficiency ηi is calculated by the torque generation efficiency calculating unit 115 and the thermal efficiency calculating unit 124, and θmb of the corrected MBT obtained by correcting θmb, which is the basic MBT, using the correction coefficient for each physical quantity, and the decrease rate A Alternatively, the torque generation efficiency K is calculated from the corrected decrease ratio Ar obtained by correcting the basic decrease ratio Ab using the correction coefficient for each physical quantity and the ignition timing IT, and is calculated from the torque generation efficiency K and the thermal efficiency η. To do. Since the intake air flow rate can be controlled with high accuracy in advance by the intake air flow rate control means 118 based on the actual thermal efficiency ηi, this embodiment can be realized.

  As described above in detail, according to the control apparatus for an internal combustion engine according to the first embodiment, the estimated torque calculation means 116 is based on the air-fuel ratio AF, the intake manifold pressure PB or the actual intake air flow rate Qr, and the actual heat efficiency ηi. The estimated output torque TRQ of the engine 1 or the estimated indicated mean effective pressure Pir is calculated. Therefore, the estimated output torque TRQ of the engine 1 can be calculated with high accuracy while suppressing the control map capacity.

  The intake air flow rate control means 118 calculates the target intake air flow rate Qt based on the target indicated mean effective pressure Pit (target output torque TRQt) calculated by the target torque calculation means 121, and achieves this target intake air flow rate Qt. Thus, the target value of the throttle opening TH is calculated, and the throttle opening TH is controlled via the throttle opening control means 119.

  Further, the ignition timing control means 117 controls the ignition timing IT based on the target torque calculation means 121, the estimated torque calculation means 116, the torque generation efficiency calculation means 115, and the thermal efficiency calculation means 124. Therefore, the driver request output torque TRQd and the torque request value from another controller can be achieved with high accuracy.

  For the EGR rate R, the air-fuel ratio AF, and the ignition timing IT, optimum values corresponding to the operating state such as the rotational speed Ne of the engine 1 and the charging efficiency Ec are stored in advance as a control map, and the target intake air flow rate Qt When the above is achieved, an optimal control value is calculated, and the EGR valve 13, the injector 14, and the ignition coil 17 are controlled using the control value as a target value, respectively, so that the optimal value is controlled.

1 engine (internal combustion engine), 2 crank angle sensor, 3 intake pipe, 4 air cleaner, 5 air flow sensor, 6 intake air temperature sensor, 7 throttle valve, 8 throttle position sensor, 9 surge tank, 10 intake manifold pressure sensor, 11 exhaust pipe , 12 EGR pipe, 13 EGR valve, 14 injector, 15 cylinder, 16 spark plug, 17 ignition coil, 18 intake valve, 19 exhaust valve, 20 air-fuel ratio sensor, 100 electronic control unit (ECU), 110 air-fuel ratio control means, 111 EGR valve opening control means, 112 EGR rate calculation means, 113 intake VVT control means, 114 exhaust VVT control means, 115 torque generation efficiency calculation means, 116 estimated torque calculation means, 117 ignition timing control means, 118 intake air flow rate control means 119 Throttle opening control means, 120 Required torque calculation means, 121 Target torque calculation means, 122 Target cylinder fresh air amount calculation means, 123 Target intake air flow rate calculation means, 124 Thermal efficiency calculation means, 125 MBT calculation means, 126 Reduction ratio Calculation means

Claims (5)

Based on the ignition timing and MBT in each operating condition of the internal combustion engine, the ignition retard amount from the MBT is calculated, and the torque is calculated from the relationship between the ignition retard amount and the torque generation efficiency in each operating condition of the internal combustion engine. In the control device for an internal combustion engine that calculates the generation efficiency and corrects the output torque from the torque generation efficiency and the thermal efficiency in each operating state of the internal combustion engine.
An intake VVT control amount calculating means for calculating an intake VVT control amount for controlling the amount of air introduced into the cylinder from the intake passage of the internal combustion engine;
Exhaust VVT control amount calculating means for calculating an exhaust VVT control amount for controlling the amount of combustion gas discharged from the cylinder to the exhaust passage of the internal combustion engine;
Basic MBT calculating means for calculating basic MBT based on intake air flow rate filling efficiency and engine rotational speed in a standard operating state of the internal combustion engine;
A first VVT correction coefficient calculating means for calculating a first VVT correction coefficient using a characteristic in which the MBT varies depending on the intake VVT control amount and the exhaust VVT control amount;
Using the characteristic that the relationship between the intake VVT control amount and the MBT moves along the intake VVT control amount according to a change in the engine rotation speed, a correction coefficient for the shift amount calculated from the engine rotation speed is calculated. Second VVT correction coefficient calculating means for
The relationship between the intake VVT control amount and the MBT is a gain amount correction coefficient calculated from the intake air flow rate charging efficiency, using a characteristic that the slope of the MBT changes with a change in the intake air flow rate charge efficiency. A third VVT correction coefficient calculating means for calculating;
The relationship between the intake VVT control amount and the MBT is such that the region of the intake VVT control amount in which the MBT is constant along the MBT direction due to a change in the exhaust VVT control amount becomes narrower. A fourth VVT correction coefficient calculating means for calculating a correction coefficient for the offset amount calculated from the exhaust VVT control amount and the engine speed;
An internal combustion engine control device comprising: MBT calculating means for correcting the basic MBT based on the correction coefficients calculated by the first to fourth VVT correction coefficient calculating means and calculating the MBT. . Based on the intake air flow rate filling efficiency in the standard operating state of the internal combustion engine and the engine speed, a basic thermal efficiency is calculated,
Using the characteristic that the relationship between the exhaust VVT control amount and the thermal efficiency can be approximated by a quadratic function, a fifth VVT correction coefficient, a sixth VVT correction coefficient, and a seventh VVT correction coefficient that are three coefficients of the quadratic function are obtained. , Based on the intake air flow rate filling efficiency and the engine speed,
Wherein the first 5VVT correction coefficient based on the first 7VVT correction coefficient, and corrects the basic thermal efficiency, control apparatus for an internal combustion engine according to claim 1, characterized in that to calculate the thermal efficiency. Target torque calculation means for calculating a target torque to be generated by the internal combustion engine based on an accelerator operation of a driver, and a target intake air flow rate for calculating a target intake air flow rate to be sucked by the internal combustion engine based on the target torque Computing means,
The target intake air flow rate calculation means corrects the target torque based on the torque generation efficiency and the thermal efficiency, and calculates the target intake air flow rate . Control device for internal combustion engine. An actual intake air flow rate calculating means for calculating an actual intake air flow rate actually sucked using an intake air flow rate in the intake pipe of the internal combustion engine; and an estimated torque to be generated from the internal combustion engine based on the actual intake air flow rate. An estimated torque calculating means for calculating ,
The estimated torque calculation means corrects the actual intake air flow rate based on the torque generation efficiency and the thermal efficiency, and calculates the estimated torque. A control device for an internal combustion engine according to item. Target torque calculation means for calculating the target torque to be generated by the internal combustion engine based on the accelerator operation of the driver, and the internal combustion engine to be generated based on the actual intake air flow rate actually taken in by the intake pipe of the internal combustion engine An estimated torque calculating means for calculating an estimated torque; and an ignition timing control means for controlling the ignition timing of the internal combustion engine,
The internal combustion engine according to claim 1 or 2 , wherein the ignition timing control means calculates the ignition timing based on the target torque, the estimated torque, the torque generation efficiency, and the thermal efficiency. Control device.

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