JPH0979092A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance setting accuracy of a target EGR rate while improving control responsiveness, by providing a cylinder intake new air amount detecting means, EGR valve target opening arithmetic means, EGR control means, etc., obtaining a target EGR amount flowing in a collector, and obtaining an opening of an EGR valve from a value of this target EGR amount and a differential pressure before and after the EGR valve. SOLUTION: A collector 6 and an exhaust manifold 7 are communicated through an exhaust gas recirculating passage (EGR passage) 9. Detection signals of a pressure sensor 22a detecting a pressure in the EGR passage 9 and a pressure sensor 22b detecting an intake pressure in an intake passage 6A are input to a control unit 15. The control unit 15 is provided with a function, in a manner of software, as a cylinder intake new air amount detecting means, target EGR rate setting means, cylinder intake target EGR amount arithmetic means, intake passage intake target EGR amount arithmetic means, EGR valve target opening arithmetic means and an EGR control means. In this way, control to a target EGR rate can be performed accurately further with a good follow-up property, and exhaust performance is improved to a maximum limit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine provided with an EGR (exhaust gas recirculation) device.

[0002]

2. Description of the Related Art Conventionally, as a control device for an internal combustion engine equipped with an EGR device, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 61-215426. Such a conventional configuration is
Cylinder head, cylinder liner of diesel engine 1,
Intake valve 2 for intake / exhaust facing a combustion chamber (hereinafter also referred to as a cylinder) formed by a piston 5 and the like.
And an exhaust valve 4, and a fuel injection valve 3 for injecting and supplying fuel. Also, the exhaust valve 4
The exhaust manifold 7 communicating with the exhaust manifold 7 is connected to the exhaust passage 7A, and the turbine of the turbocharger 8 is interposed in the exhaust passage 7A.

On the other hand, an intake passage 6A is connected to the collector 6 communicating with the intake valve 2, and a compressor connected to the turbine of the turbocharger 8 is interposed in the intake passage 6A, and the compressor is connected to the intake passage 6A. Due to this, supercharged intake air is introduced. It should be noted that, in order to control the boost pressure to a desired level, the valve is opened at a predetermined exhaust pressure so that the exhaust energy is not supplied to the turbine more than a predetermined amount, and a part of the exhaust gas bypasses the turbine and is discharged as it is. Bypass passage 7B and waste gate valve 12
a is provided.

The collector 6 and the exhaust manifold 7 recirculate a part of the exhaust gas to the intake system (EGR).
The exhaust gas recirculation passage 9 for communicating is connected.
In the EGR passage 9, a desired EGR rate (exhaust gas recirculation amount /
EG whose opening is continuously controlled by the EGR valve driving linear solenoid 11b in order to obtain a fresh air intake air flow rate).
The R valve 11a is interposed. Further, in the intake passage 6A, a linear solenoid 10b for driving the intake throttle valve is used to achieve a desired EGR rate over a wider range.
An intake throttle valve 10a capable of continuously controlling the intake pressure is provided.

Further, an air flow meter 13 for detecting the fresh air intake air flow rate is provided at the inlet of the intake passage 6A. The control unit 15 for controlling the conventional internal combustion engine having the above-described configuration functions as described below and achieves the target EGR rate according to the operating state, so that the operating performance, the black smoke, the particulates, Exhaust performance (especially effective in reducing NOx. HC can also be reduced at low temperatures, etc.), noise (reduction of dP / dθ), etc., while suppressing deterioration of fuel consumption within a predetermined range. I am trying.

The target EGR rate setting unit 15a sets the target EGR rate based on the accelerator opening, the engine speed, and the like. In the EGR valve / intake throttle valve target opening degree setting unit 15c, the target E which is the output from the target EGR rate setting unit 15a.
The target EGR valve opening degree and the target intake throttle valve opening degree are output based on the GR rate and the predicted value of the predicted EGR rate calculation unit 15f described later.

In the EGR valve opening control section 15d and the intake throttle valve opening control section 15e, according to the input target value, the EGR valve
Opening control of the valve 11a and the intake throttle valve 10a (current control for driving the solenoid) is performed. Predicted EGR rate calculator 15
Inside f, the mass flow rate of the gas (fresh air + EGR gas) flowing into the cylinder is obtained in the cylinder intake air amount calculation unit 15g based on the operating state of the engine (accelerator opening degree, engine rotation speed, etc.), and The mass flow rate of fresh air flowing into the collector 6 is obtained from the output of the air flow meter 13 in the intake fresh air amount conversion unit 15i.

In the intake EGR amount calculation unit 15h to the collector, the mass flow rate of the gas flowing to the cylinder, which is the output of the intake air amount calculation unit 15g to the cylinder, and the output of the intake fresh air amount conversion unit 15i to the collector. The mass flow rate of the EGR gas flowing to the collector 6 is obtained by finding the difference between the mass flow rate of the fresh air flowing to the collector 6 and the mass flow rate of the fresh air. Regarding the EGR rate calculation unit 15j, the mass flow rate of EGR gas flowing to the collector 6, which is the output of the intake EGR amount calculation unit 15h to the collector, and the mass flow rate of EGR gas to the collector, which is the output of the intake fresh air amount conversion unit 15i, flow to the collector 6. The mass flow rate of fresh air is input, and the predicted value of the EGR rate is output.

[0009]

In the conventional EGR device described above, it is considered that the mass flow rate of the entire gas flowing to the cylinder is equal to the sum of the mass flow rates of the EGR gas flowing to the collector 6 and the fresh air, and the mass flow rate to the collector 6 is considered. The mass flow rate of the EGR gas flowing is equal to the mass flow rate difference between the mass flow rate of the entire gas flowing to the cylinder and the mass flow rate of the fresh air flowing to the collector 6. Further, the expected EGR rate is obtained from the mass flow rate of fresh air and EGR gas flowing to the collector 6.

However, in reality, the mass flow rate of the entire gas flowing to the cylinder may not be the sum of the mass flow rates of the fresh air flowing to the collector and the EGR gas (for example, when the idle state is changed to the acceleration state). , When the flow rate to the collector suddenly increases, but the flow rate to the cylinder gradually increases with a delay, etc.), the mass flow rate of the entire gas flowing to the cylinder and the mass flow rate of fresh air flowing to the collector , Is not accurate as the predicted value of the mass flow rate of EGR gas flowing to the collector, and the predicted value of the EGR rate obtained from this value and the mass flow rate of fresh air flowing to the collector may not be accurate. That is, as a result, the target EGR rate that is the control target becomes inaccurate, and there is a possibility that the exhaust performance cannot be maximized while maintaining the operating performance and the like.

Further, the prediction of the EGR rate in the conventional device is the EGR rate of the gas sucked into the collector, which is different from the EGR rate of the gas sucked into the cylinder to be originally controlled, and is associated with the above problem. Therefore, there is a fear of causing a decrease in the accuracy of EGR control. Furthermore, each valve (EGR
The mass flow rate flowing through the valve 11a and the intake throttle valve 10a) is determined by the differential pressure before and after the valve and the valve opening.
When setting the opening of each valve in order to achieve the GR rate (quantity), the information about the differential pressure across each valve was not given, so the followability with respect to the target value could not be sufficiently improved.

The present invention has been made in view of such a conventional situation, and the EGR rate of the gas sucked into the cylinder is the target E.
EGR from the EGR valve to the intake valve so that the GR rate is achieved
The target E that flows into the collector (intake passage of the portion filled with exhaust gas recirculation gas) in consideration of the dynamic characteristics of the gas
By determining the GR amount and directly determining the opening of the EGR valve from this value and the differential pressure across the EGR valve, the control responsiveness is increased and the setting accuracy of the target EGR rate is increased.
An object of the present invention is to provide a control device for an internal combustion engine, which is designed to improve the accuracy of R control. It is also an object of the present invention to further improve the accuracy of this device.

[0013]

Therefore, as shown in FIG. 1, an internal combustion engine control apparatus according to a first aspect of the present invention, an exhaust gas recirculation passage communicating an exhaust passage and an intake passage of the internal combustion engine. And an exhaust gas recirculation valve for controlling the exhaust gas recirculation rate, which is interposed in the exhaust gas recirculation passage, and a cylinder intake fresh air amount detection for detecting an amount of fresh air sucked into a cylinder. Means, a target exhaust gas recirculation ratio setting means for setting a target exhaust gas recirculation ratio according to the engine operating state, a fresh air amount sucked into the cylinder, and the target exhaust gas recirculation ratio, based on the target exhaust gas recirculation ratio. A cylinder intake target exhaust gas recirculation amount calculation means for calculating a target exhaust gas recirculation amount to be sucked in, a calculated cylinder intake target exhaust gas recirculation amount, and a dynamic exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve. Based on the characteristics and the And an intake manifold intake target exhaust gas recirculation amount calculating means for calculating an exhaust gas recirculation amount of the target should, with the computed intake passage inhalation target exhaust gas recirculation amount, and the pressure in the intake passage,
Based on the pressure in the exhaust gas recirculation passage and the exhaust gas density, an exhaust gas recirculation valve target opening degree calculation means for calculating a target opening degree of the exhaust gas recirculation valve, and the calculated target opening degree are obtained, And an exhaust gas recirculation control unit that drives and controls the exhaust gas recirculation valve.

In this way, the target exhaust gas recirculation amount flowing into the intake passage is obtained in consideration of the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the intake valve. Since the opening degree of the exhaust gas recirculation valve is calculated based on the differential pressure and is controlled to the opening degree, the target exhaust gas recirculation rate to be sucked into the cylinder can be accurately and accurately followed. The target exhaust gas recirculation rate can be satisfactorily achieved not only during steady operation but also during transient operation, so that deterioration of operating performance, black smoke, particulates, fuel consumption, etc. can be specified. It is possible to improve exhaust performance, noise, etc. to the maximum while suppressing it within the range. In the invention according to claim 2, the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve are the engine speed, the intake passage volume of the portion filled with the exhaust gas recirculation gas, and the stroke volume. And the volumetric efficiency are calculated.

As a result, the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve can be calculated with high accuracy. According to a third aspect of the present invention, the cylinder intake fresh air amount detecting means is based on a fresh air amount sucked into the intake passage and a dynamic characteristic of the sucked fresh air to the cylinder. It is configured by means for obtaining the amount of fresh air drawn into the cylinder.

With this, it is not necessary to actually measure the amount of fresh air drawn into the cylinder with a special sensor or the like, so that the cost can be reduced and the layout and the layout can be improved as compared with the case where the sensor or the like is provided near the intake valve. It is possible to prevent deterioration of ventilation resistance and air flow characteristics (swirl ratio, etc.). Claim 4
In the invention described in, the dynamic characteristics of the fresh air to the cylinder,
The calculation is performed based on the engine speed, the intake passage volume, the stroke volume, and the volume efficiency.

As a result, the dynamic characteristics of the fresh air cylinder can be calculated with high accuracy. In the invention described in claim 5, the volumetric efficiency is estimated based on the engine speed and the pressure in the intake passage.

With this, the volumetric efficiency can be estimated with high accuracy, so that a special sensor for measuring the volumetric efficiency is not required, and the cost can be reduced. In the invention according to claim 6, when the intake throttle valve is provided in the intake passage upstream of the communicating portion between the intake passage and the exhaust gas recirculation passage, the amount of fresh air sucked into the intake passage is equal to the opening of the intake throttle valve. And the pressure in the intake passage downstream of the intake throttle valve, the pressure in the intake passage upstream of the intake throttle valve, and the atmospheric density.

As a result, the amount of fresh air taken into the intake passage can be calculated with high accuracy, so that it is not necessary to measure it with a special sensor, and the cost can be reduced. Claim 7
In the invention described in (1), the intake throttle valve opening is set based on the target exhaust gas recirculation rate set by the target exhaust gas recirculation rate setting means, and the intake throttle valve opening is obtained so as to obtain the intake throttle valve opening. Is configured to be driven and controlled by the intake throttle valve control means. In the invention according to claim 8, the pressure in the intake passage downstream of the intake throttle valve is the temperature in the exhaust gas recirculation passage, the temperature in the intake passage upstream of the intake throttle valve, the engine speed, and the volumetric efficiency. It is configured to be calculated based on the amount of fresh air sucked into the cylinder, the amount of exhaust gas recirculation sucked into the cylinder, the stroke volume, the molecular weight of the atmosphere, and the molecular weight of the exhaust gas.

As a result, the pressure in the intake passage downstream of the intake throttle valve can be calculated with high accuracy, and it is not necessary to measure it with a special sensor, so that the cost can be reduced. In the invention according to claim 9, when the internal combustion engine is provided with a supercharger, the temperature in the exhaust gas recirculation passage is the temperature in the intake passage upstream of the intake throttle valve, and the fresh air drawn into the cylinder. It is configured to be calculated based on the amount, the exhaust gas recirculation amount sucked into the cylinder, the pressure in the exhaust gas recirculation passage, the atmospheric pressure, the specific heat ratio of the exhaust gas, and the fuel injection amount.

As a result, the temperature in the exhaust gas recirculation passage can be calculated with high accuracy, and it is not necessary to measure it with a special sensor, so that the cost can be reduced. Claim 10
In the invention described in (1), when the internal combustion engine is provided with a supercharger, the temperature in the intake passage upstream of the intake throttle valve is the pressure in the intake passage upstream of the intake throttle valve, the atmospheric pressure, and the specific heat of the atmosphere. It is configured to be calculated based on the ratio and the efficiency of the compressor of the supercharger.

As a result, the temperature in the intake passage upstream of the intake throttle valve can be calculated with high accuracy, and it is not necessary to measure it with a special sensor, so that the cost can be reduced. According to the invention described in claim 11, the exhaust gas recirculation amount sucked into the cylinder is based on the dynamic characteristic of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve, and the exhaust gas recirculation amount sucked into the intake passage is returned. It was configured to be calculated from the flow rate.

As a result, the amount of exhaust gas recirculated into the cylinder can be calculated with high accuracy, and it is not necessary to measure it with a special sensor, so that the cost can be reduced. In the invention according to claim 12, the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve are the engine speed, the intake passage volume downstream of the intake throttle valve, the stroke volume, and the volumetric efficiency. And is configured to be calculated based on.

As a result, the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve can be calculated with high accuracy. In the invention according to claim 13, the exhaust gas recirculation amount sucked into the intake passage is such that the opening degree of the exhaust gas recirculation valve, the pressure in the intake passage downstream of the intake throttle valve, the pressure in the exhaust recirculation passage, and the exhaust gas It is configured to be calculated based on the density and.

As a result, the amount of exhaust gas recirculated into the intake passage can be calculated with high accuracy, and it is not necessary to measure it with a special sensor, so that the cost can be reduced.
According to the fourteenth aspect of the invention, the volumetric efficiency is estimated based on the engine speed and the pressure in the intake passage downstream of the intake throttle valve.

Since this makes it possible to estimate the volumetric efficiency with high accuracy, a special sensor for measuring the volumetric efficiency is not required, and the cost can be reduced. According to a fifteenth aspect of the present invention, when the internal combustion engine is not equipped with a supercharger, the pressure in the intake passage or the pressure in the intake passage upstream of the intake throttle valve is set as atmospheric pressure, and the temperature in the intake passage or the intake air is increased. Various calculations were performed with the temperature in the intake passage upstream of the throttle valve as the atmospheric temperature.

As a result, the arithmetic processing can be simplified. According to the sixteenth aspect of the invention, when the internal combustion engine is not provided with a supercharger, the temperature in the exhaust gas recirculation passage is set to the atmospheric temperature, the amount of fresh air drawn into the cylinder, and the amount of fresh air drawn into the cylinder. It is configured to be calculated based on the exhaust gas recirculation amount and the fuel injection amount.

As a result, the arithmetic processing can be simplified.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 shows the overall configuration of the first embodiment of the present invention. The same elements as those of the conventional apparatus will be described with the same reference numerals. An intake valve 2 and an exhaust valve 4 for intake / exhaust are provided facing a combustion chamber (cylinder) formed by a cylinder head, a cylinder liner, a piston 5 and the like of the diesel engine 1, and fuel is injected and supplied. The fuel injection valve 3 is provided. An exhaust manifold 7 communicating with the exhaust valve 4 is connected to an exhaust passage (hereinafter, also referred to as an exhaust pipe) 7A, and a turbocharger (hereinafter, also referred to as a supercharger) 8 is provided in the exhaust passage 7A. A turbine is installed. A wastegate valve 12a is also provided in the bypass passage 7B as in the conventional case.

On the other hand, an intake passage (hereinafter also referred to as an intake pipe) 6A is connected to the collector 6 communicating with the intake valve 2, and the turbocharger 8 is installed in the intake passage 6A.
A compressor connected to the turbine is installed so that intake air supercharged by the compressor is guided. Here, the collector 6 corresponds to the "intake passage of the portion filled with the exhaust gas recirculation gas" in the present invention.

By the way, in this embodiment, the turbocharger 8 is used for explanation, but not limited to the turbocharger, it is also possible to adopt another supercharger (supercharger, complex type supercharger, etc.). . Further, although a four-cylinder engine is assumed in this embodiment, the invention is not limited to this. And the collector 6
And the exhaust manifold 7, an exhaust gas recirculation passage (hereinafter, referred to as E) for recirculating (EGR) a part of the exhaust gas to the intake system.
A GR pipe and an EGR passage 9 are connected to each other, and the EGR passage 9 is continuously connected by an EGR valve driving linear solenoid 11b in order to obtain a desired EGR rate (exhaust gas recirculation amount / fresh air intake air flow rate). An exhaust gas recirculation valve (hereinafter, also referred to as an EGR valve) 11a whose opening degree is controlled is interposed. Here, the EGR valve driving linear solenoid 11
b, the control unit 15 constitutes the exhaust gas recirculation control means in the present invention.

The intake passage 6A is provided with an intake throttle valve 10a capable of continuously controlling the intake pressure by a linear solenoid 10b for driving an intake throttle valve so that a desired EGR rate can be achieved over a wider range. It is equipped. here,
The intake throttle valve driving linear solenoid 10b and the control unit 15 constitute intake throttle valve control means in the present invention.

Further, instead of the air flow meter 13 used in the conventional device, in the present embodiment, a pressure sensor 22a for detecting the pressure (Pegr) in the EGR passage 9 and an intake passage 6A (downstream of the compressor). A pressure sensor 22b for detecting the intake pressure (Pint) in the intake throttle valve 10a). The detection signals of these pressure sensors 22a and 22b are input to the control unit 15.

The control unit 15 includes a CPU and R
A microcomputer for engine control equipped with an OM, RAM, input / output I / F, A / D converter and the like.
In addition to the detection signals of a and 22b, various signals (accelerator opening,
The engine rotation speed, engine temperature (for example, cooling water temperature), etc. are input, and the following functions are performed. That is, the control unit 15 includes the cylinder intake fresh air amount detection means, the target exhaust gas recirculation rate setting means, the cylinder intake target exhaust gas recirculation amount calculation means, the intake passage intake target exhaust gas recirculation amount calculation means, and the exhaust gas recirculation valve target opening degree. This means that it has software functions as a calculation means and an exhaust gas recirculation control means.

The fuel injection amount setting unit 15B in the control unit 15 sets the fuel injection amount (Qf) based on the accelerator opening, the engine rotation speed, the engine temperature and the like. Here, an example of the setting map of the fuel injection amount is shown in FIG. In the target EGR rate setting unit 15a, based on the fuel injection amount Qf which is the output from the fuel injection amount setting unit 15b, the engine rotation speed, the engine temperature, etc. Value). Here, an example of the setting map of the target EGR rate is shown in FIG.
It shows in 6.

In each valve target opening calculation unit 16, the target EGR is calculated.
Ratio, engine speed, fuel injection amount Qf which is an output from the fuel injection amount setting unit 15B, pressure (Pegr) in the EGR passage 9 which is an output of the pressure sensor 22a, and output of the pressure sensor 22b. Pressure in the intake passage 6A (Pin
t) and are input, and the target EGR valve opening and the target intake throttle valve opening are output. A calculation example in the calculation unit 16 will be described later.

In the EGR valve opening control unit 15d and the intake throttle valve opening control unit 15e, the target values (target EGR valve opening, target intake throttle valve opening) calculated and input by each valve target opening calculation unit 16 are input. Degree), the opening degree of each valve is controlled (current control of the solenoid). Here, each valve target opening calculation unit 16
The calculation processing in will be described.

In the cylinder intake fresh air amount / collector internal pressure calculating section and volume efficiency estimating section 17, the engine speed and Qf are calculated.
, Pint, Pegr, and the target EGR valve opening area (Ae
gr) and the target intake throttle valve opening area (Atvo), which is the output of the intake throttle valve 16a, as inputs.
The internal pressure (Pcol), the mass flow rate (Qcw) of fresh air flowing to the cylinder, and the volumetric efficiency (ηv) are output.
The process will be described later.

The intake throttle target opening calculation unit 16a obtains and outputs Atvo and the target intake throttle opening by a map search or the like from the target EGR rate. The target intake throttle valve opening is obtained from Atvo using a map showing the relationship between the opening and the opening area. FIG. 18 shows an example of the intake throttle valve opening setting map. The intake throttle valve 10a is
When increasing the R rate, the opening is reduced
It is intended to reduce the ol and facilitate the EGR gas to flow into the collector 6.

In the collector target EGR amount calculation unit 18, η
The target EGR amount (MQe) to the collector 6 is output by inputting v, Qcw, the target EGR rate, and the engine speed. The process will be described later. In the EGR valve target opening calculation unit 19, Pcol, Pegr, and MQe
, And Aegr, the target EGR valve opening degree,
Is output. The target EGR valve opening is obtained from Aegr using a map showing the relationship between the opening and the opening area. EGR
An example of the valve opening degree setting map is shown in FIG. 18 (note that the intake throttle valve 10a and the EGR valve 11a are driven with similar characteristics). Inside the EGR valve target opening calculation unit 19, for example, a calculation using the Bernoulli's equation as described below is performed.

Aegr = MQe / [2 (Pegr-Pc
ol) · ρexh] ^1/2 MQe (kg / sec): Target EGR amount of collector Pegr (Pa): Pressure in EGR passage Pcol (Pa): Pressure in collector ρexh (kg / m ³ ): Exhaust density Aegr (M ² ): Target EGR valve opening area Here, ρexh may be given as a constant or may be a measured value. Next, the processing in the cylinder intake fresh air amount / collector internal pressure calculation unit and the volumetric efficiency estimation unit 17 will be described.

The intake fresh air amount calculating unit 17a receives Pint, Pcol, and Atvo (the target intake throttle valve opening area is substantially equal to the actual opening area) as inputs, and a new flow to the collector 6 is performed. Qi mass flow rate (Qw)
Is output. Intake fresh air amount calculator 17a to this collector
Inside of, for example, the calculation using Bernoulli's formula as follows is performed.

Qw = {[2 (Pint-Pcol) × ρ
a] ^1/2 } × Atvo Qw (kg / sec): Fresh intake air amount to collector Pint (Pa): Pressure in intake passage Pcol (Pa): Pressure in collector Atvo (m ² ): Target intake throttle Valve opening area ρa (kg / m ³ ): Atmospheric density Here, ρa may be given as a constant or may be an actually measured value.
In the intake EGR amount calculation unit 17b for the collector, Pegr
, Pcol, Aegr (target EGR valve opening area is
And the mass flow rate (Qe) of the EGR gas flowing to the collector 6 are output. In the inside of the intake EGR amount calculation unit 17b for this collector, for example, the calculation using the Bernoulli's equation as follows is performed.

Qe = {[2 (Pegr-Pcol.
Z ⁻¹ ) × ρexh] ^1/2 } × (Aegr · Z ⁻¹ ) Qe (kg / sec): Intake EGR amount to the collector Pegr (Pa): Pressure in the EGR passage Pcol (Pa): Inside the collector Pressure Aegr (m ² ): Target EGR valve opening area ρexh (kg / m ³ ): Exhaust density Here, ρexh may be given as a constant or may be a measured value. In the intake fresh air amount calculation unit 17c for the cylinder, Qw
, The engine speed, and ηv are input, and Qcw is output. The following calculation is performed, for example, inside the intake air fresh air amount calculating unit 17c.

Qcw = {1 / [30Vcol / (Vcyl · ηv
・ Δt ・ Ne) +1]} × Qw + {1-1 / [30Vcol
/ (Vcyl ・ ηv ・ Δt ・ Ne) +1]} × (Qcw ・ Z
^-1 ) Qcw (kg / sec): Intake fresh air amount into the cylinder Vcol (m ³ ): Collector volume Vcyl (m ³ ): Stroke volume Δt (sec): 1 calculation time Ne (rpm): Engine rotation speed ηv : Volume efficiency Qw (kg / sec): Intake fresh air amount to the collector Here, Vcol, Vcyl, and Δt are given as constants. In the intake EGR amount calculation unit 17d for the cylinder, Qe
, The engine rotation speed, and ηv are input, and the mass flow rate (Qce) of the EGR gas flowing to the cylinder is output.
The following calculation is performed, for example, inside the intake EGR amount calculation unit 17d for this cylinder.

Qce = {1 / [30Vcol / (Vcyl ・ [ηv ・ Z
⁻¹ ] · Δt · Ne) +1]} × Qe + {1-1 / [30Vcol /
(Vcyl ・ [ηv ・ Z ^-1 ] ・ Δt ・ Ne) +1]} × (Qc
e · Z ⁻¹ ) Qce (kg / sec): EGR amount sucked into the cylinder Vcol (m ³ ): Collector volume Vcyl (m ³ ): Stroke volume Δt (sec): 1 calculation time Ne (rpm): Engine rotation Velocity ηv: Volumetric efficiency Qe (kg / sec): Intake EGR amount to collector Here, Vcol, Vcyl, and Δt are given as constants. The intake passage internal temperature calculation unit 17e receives Pint as an input and outputs an intake passage internal temperature (Tint). In the inside of the intake passage temperature calculation unit 17e, for example, the following calculation is performed.

Tint = {[Pint / Pa] ^{(1-1 / ka)}
−1 + ηcom} × Ta / ηcom Tint (K): Temperature in intake passage Ta (K): Temperature of atmosphere Pint (Pa): Pressure in intake passage Pa (Pa): Atmospheric pressure ka: Specific heat ratio of atmosphere ηcom: Efficiency of compressor of supercharger Here, Ta, ηcom, Pa, ka may be given as constants or may be measured values.

In the collector internal pressure calculation unit 17g, Tint
, Temperature in the EGR passage (Tegr), Qce, Q
The cw, ηv, and the engine speed are input, and the collector internal pressure (Pcol) is output. Inside the collector internal pressure calculation unit 17g, for example, the following calculation is performed. Pcol = 30Ra / (Vcyl ・ [ηv ・ Z ^-1 ] ・ Ne) ・ {(Qcw
・ Z ^-1 ) ・ Tint} + 30Rexh / (Vcyl ・ [ηv ・ Z ^-1 ]
・ Ne） ・ (Qce ・ Tegr) Pcol (Pa): Pressure inside the collector Ra (Pa ・ m ³ / K ・ kg): Gas constant / (Atmospheric molecular weight ・ 1)
0 ^-3 ) Rexh (Pa ・ m ³ / K ・ kg): Gas constant / (Exhaust molecular weight ・ 1
0 ^-3 ) Vcyl (m ³ ): Stroke volume Ne (rpm): Engine rotation speed ηv: Volumetric efficiency Qcw (kg / sec): Intake fresh air amount into the cylinder Qce (kg / sec): Intake into the cylinder EGR Quantity Tint (K): Temperature in intake passage Tegr (K): Temperature in EGR passage Here, Vcyl is given as a constant. Ra and Rexh
May be given as a constant or may be a measured value. The volumetric efficiency estimation unit 17h inputs Pcol and the engine rotation speed and outputs ηv using a map prepared in advance. FIG. 17 shows an example of the volumetric efficiency setting map. E
In the GR passage internal temperature calculation unit 17f, Tint and Qce
, Qcw, Pegr, and Qf as inputs, and E
The temperature (Tegr) in the GR passage 9 is output. This EG
The internal processing in the R passage internal temperature calculation unit 17f will be described later. In the collector temperature calculation unit 21a, Tint and Q
Collector 6 using cw, Qce, and Tegr
The temperature (Tcol) of is output. Inside the collector temperature calculation unit 21a, for example, the following calculation is performed. The following equation approximates the heat balance equation within a practical EGR rate range.

Tcol = 273 + (Tint-273) + (Tegr.Z- ¹⁾
-273) ・ {Qce / (Qcw ・ Z ^-1 )} Tcol (K): Temperature in collector Tint (K): Temperature in intake passage Tegr (K): Temperature in EGR passage Qcw (kg / sec) : Amount of fresh air sucked into the cylinder Qce (kg / sec): Amount of EGR sucked into the cylinder In the exhaust temperature estimation unit 21d, the temperature (Texh) downstream of the turbine of the supercharger 8 is input with Tcol and Qf as inputs.
Is output. Inside the exhaust temperature estimation unit 21d, for example, the following calculation is performed.

Qfo = Qf · Z ^{−2 * (30 / Ne)} Qf (kg / stroke): Fuel injection amount Ne (rpm): Engine rotation speed Next, from Qfo, using a map prepared in advance, T
Set exhb. An example of the Texhb setting map,
As shown in FIG.

Then, the following calculation is performed using Tcol to obtain Tno. Tno = Tcol · Z ^{−3 * (30 / Ne)} Tcol (K): Temperature in collector Ne (rpm): Engine speed Next, the following calculation is performed using Tno and Texhb. Then, Texh is obtained.

Texh = Texhb × Tno Texh (K): Temperature downstream of turbine of supercharger In the exhaust passage internal temperature calculation unit A (21e), Pegr is input and kTexh is output (the output of 21e is kT
exh). In the inside of this 21e, for example, the following calculation is performed. kTexh = (Pegr / Pa) ^{(1-1 / ke)} Pegr (Pa): Temperature in EGR passage Pa (Pa): Atmospheric pressure ke: Specific heat ratio of exhaust gas Here, ke is a constant or is also an actually measured value. Good.
In the exhaust passage internal temperature calculation unit B (21f), Texh,
Using kTexh as an input, the temperature (Tturbo) in the exhaust passage (the portion surrounded by the upstream of the EGR passage 9, the upstream of the turbine of the supercharger 8 and the upstream of the waste gate 12a) is output. Inside this 21f, the following calculation is performed assuming, for example, adiabatic compression.

Tturbo = Texh × kTexh Tturbo (K): temperature in exhaust passage Texh (K): temperature downstream of turbine of supercharger EGR passage internal temperature calculation unit 21g receives Tturbo and outputs Tegr. Within this 21g, for example, the following calculation is performed. Note that kTl
os is a constant determined from the experimental results of Tturbo and Tegr.

Tegr = kTlos × (Tturbo-
273) +273 Tturbo (K): temperature in exhaust passage Tegr (K): temperature in EGR passage Next, the processing in the target EGR amount calculation unit 18 will be described.

In the cylinder target EGR amount calculation unit 18a,
For example, as shown below, the target EGR rate (%) is multiplied by Qcw, and the mass flow rate of the EGR gas (M
Qce) is calculated. MQce = target EGR rate × 0.01 × Qcw MQce (kg / sec): target EGR amount of cylinder Qcw (kg / sec): intake EGR amount to the cylinder In the advance processing calculator 18b, MQce, ηv, engine The rotation speed and are input, and MQe is output. The processing in the advance processing calculator 18b will be described.

The advance processing calculation unit A (20a) receives the engine speed and ηv and performs the following calculation. The output of this 20a is Kvol. Kvol = {1 / [30Vcol / (Vcyl ・ ηv ・ Δt ・ Ne) +
1]} Vcol (m ³ ): collector volume Vcyl (m ³ ): stroke volume Δt (sec): 1 calculation time Ne (rpm): engine rotation speed ηv: volume efficiency where Vcol, Vcyl, and Δt are constants give. In the advance processing calculation unit B (20b), Kvol and M
Qce is input and Kqce is output. 20b
Inside, the following calculation is performed, for example.

Kqce = Kvol · MQce + (1-K
vol) · (Kqce · Z ⁻¹ ) MQce (kg / sec): target EGR amount of cylinder collector target EGR amount calculation unit 20c
Kqce and are input, and MQe is output. This 2
Inside 0c, for example, the following calculation is performed.

MQe = 2.MQce-Kqce MQe (kg / sec): Target EGR amount of collector MQce (kg / sec): Target EGR amount of cylinder Here, FIG. 9 shows the actual EGR rate and the conventional EGR rate. Prediction E
The comparison result of GR rate is shown. Fig. 10 shows the actual EGR
The result of comparison between the rate and the predicted EGR rate (obtained from the ratio of Qcw and Qce) in the first embodiment of the present invention is shown. Note that the simulation results are obtained in any case.

The predicted EGR rate in the conventional apparatus is the mass flow rate of fresh air flowing into the collector 6 without considering the dynamic characteristics from the intake throttle valve 10a to the intake valve 2 and from the EGR valve 11a to the intake valve 2. And EGR flowing into the collector 6
It is the ratio of the mass flow rate of the gas. However, the mass flow rate of the EGR gas flowing into the collector 6 is calculated from the mass flow rate of the mixture of fresh air and EGR gas flowing into the cylinder,
The mass flow rate of fresh air flowing into the collector 6 is subtracted. Note that the prediction E in the first embodiment of the present invention
The GR rate considers the dynamic characteristics described above.
Further, in the first embodiment, when setting the opening degree of the EGR valve 11a, the opening degree is set after considering the differential pressure across the EGR valve 11a. In comparison, the followability has been greatly improved.

From FIGS. 9 and 10, it can be seen that the first embodiment can improve the prediction accuracy of the EGR rate during a transition as compared with the conventional device. The operating conditions shown in FIGS. 9 and 10 are for the case where the idle operation is continued for 7 seconds and then the acceleration state is entered. As described above, according to the first embodiment, the target EGR amount flowing into the collector 6 is obtained in consideration of the dynamic characteristics of the EGR gas from the EGR valve 11a to the intake valve 2, and this value , The target EG to be sucked into the cylinder by directly calculating the opening degree of the EGR valve 11a based on the differential pressure across the EGR valve 11a.
The R rate can be controlled accurately and with good followability, and the target E can be controlled not only during steady operation but also during transient operation.
GR rate can be achieved satisfactorily, so that operating performance,
Exhaust performance (especially effective for reducing NOx while suppressing deterioration of black smoke, particulates, fuel consumption, etc. within a predetermined range.
HC can also be reduced at low temperature and light load), noise (reduction of pressure increase rate dP / dθ), etc. can be maximally improved. For example, at a low load, a relatively high EG
Since EGR can be applied at the R rate, NOx can be reduced to the maximum by reducing the combustion speed, and
Since the pressure increase rate (dP / dθ) is reduced, noise can be reduced, and EGR can be reduced with high transient response and high accuracy even when transitioning from a low load to a high load. Therefore, it is possible to minimize deterioration of black smoke, particulates, and drivability.

Further, since it is not necessary to perform the reduction correction of the fuel injection amount which is conventionally performed to suppress the deterioration of the black smoke and the like due to the EGR control delay at the transition time, the drivability (acceleration feeling, etc.) is also eliminated. ) Can be prevented from worsening. The EGR in the first embodiment
Regarding the portion for calculating the target opening of the valve 11a, the differential pressure before and after the EGR valve disclosed in Japanese Patent Application No. 7-92631 by the present applicant (pressure in the EGR passage 9 and collector 6). It has the following effects for predicting (difference from pressure).

A calculation for predicting the pressure in the EGR passage 9 becomes unnecessary, and a cheaper control unit can be used. And, in the one disclosed in Japanese Patent Application No. 7-92631, even if the characteristics of the EGR control system change due to changes over time in manufacturing variations of the exhaust system and the intake system, foreign matter volume, etc., it cannot be compensated. According to the first embodiment of the present invention, since the pressure in the EGR passage 9 is measured, it is possible to compensate for the change in the above characteristics and maintain high EGR control accuracy even after long-term use. You can
It is possible to further improve quality and the like. Continued to,
The second to fifth embodiments of the present invention will be described.

In the second to fourth embodiments,
At least one of the temperature in the EGR passage 9 and the temperature in the intake passage 6A is actually measured. The fifth embodiment is
It is an embodiment when a supercharger is not provided. FIG.
FIG. 6 is a diagram showing an overall configuration of a second exemplary embodiment of the present invention.

The second embodiment differs from the first embodiment in the EGR passage internal temperature detecting means (temperature sensor 23a) for actually measuring the temperature (Tegr) upstream of the EGR valve 11a in the EGR passage 9. Is added, and the others are the same. In the second embodiment, of course, the same effects as in the first embodiment are obtained, and further simplification of the arithmetic processing is achieved, and Tegr is given as an actual measurement value (detection value). The calculation process in the EGR passage internal temperature calculation unit 17f in the first embodiment is unnecessary, and the measured value (detection value) Tegr is included in the collector internal pressure calculation 17g.
Will be input. FIG. 12 is a diagram showing the overall configuration of the third embodiment of the present invention.

The third embodiment differs from the first embodiment in the intake passage temperature detecting means (temperature sensor 23b) for actually measuring the temperature (Tint) upstream of the intake throttle valve 10a in the intake passage 6A. ) Is added, and the others are the same. In the third embodiment, of course, the same effects as those of the first embodiment are obtained, and further simplification of the arithmetic processing is achieved, and Tint is given as an actual measurement value (detection value). In the first embodiment, the calculation process in the intake air passage temperature calculation unit 17e becomes unnecessary, and the measured value (detection value) Tint is input to the collector internal pressure calculation 17g and the EGR passage temperature calculation unit 17f. become. FIG. 13: is a figure which shows the whole structure of the 4th Embodiment of this invention.

The fourth embodiment differs from the first embodiment in that the temperature sensor 23a for actually measuring the temperature (Tegr) upstream of the EGR valve 11a in the EGR passage 9 and the intake air in the intake passage 6A. Temperature upstream of the throttle valve 10a (Tin
The temperature sensor 23b for actually measuring t) is added. In the fourth embodiment, not only the same effects as in the first embodiment are achieved, but also the arithmetic processing is further simplified, and Tegr and Tint are given as actual measurement values. In the above embodiment, the calculation processing in the EGR passage internal temperature calculation unit 17f and the intake passage internal temperature calculation unit 17e becomes unnecessary, and the measured values Terg and Tint are input to the collector internal pressure calculation unit 17g. FIG. 14: is a figure which shows the whole structure of the 5th Embodiment of this invention.

The fifth embodiment differs from the first embodiment in that the supercharger 8 is removed and the pressure sensor for detecting (actually measuring) the pressure (Pint) upstream of the intake throttle valve 10a in the intake passage 6A. 22b is removed. In the fifth embodiment, the pressure (Pint) upstream of the intake throttle valve 10a in the intake passage 6A is equal to the atmospheric pressure. The temperature (Tint) upstream of the intake throttle valve 11a in the intake passage 6A is equal to the atmospheric temperature.
Therefore, the same effect as that of the first embodiment can be obtained, and the intake passage internal temperature calculation unit 17 of the first embodiment can be obtained.
The calculation processing in e becomes unnecessary. In addition, the calculation process in the exhaust passage internal temperature calculation unit A (21e) in the first embodiment is also unnecessary, and kTexh is equal to "1". Therefore, Tturbo becomes equal to Texh, and the calculation process in the exhaust passage temperature calculating unit 21f is also unnecessary. By the way, in each of the above embodiments, the intake throttle valve 10a can be omitted. That is, although the intake throttle valve 10a is usually used to increase the intake negative pressure so as to achieve the desired EGR rate, when the desired EGR rate is obtained without providing the intake throttle valve 10a (for example, , When the required EGR rate is originally low, or when the EGR rate is originally applied to a spark ignition type engine that has a throttle valve and has a large intake negative pressure).

The present invention can be applied not only to the direct injection type diesel engine but also to the sub-chamber type diesel engine, and also to the spark ignition type Otto engine.

[0069]

As described above, according to the present invention,
Considering the dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the intake valve, the target exhaust gas recirculation amount that flows into the intake passage is determined, and based on this value and the differential pressure before and after the exhaust gas recirculation valve. Since the degree of opening of the exhaust gas recirculation valve is calculated and controlled to that degree of opening, the target exhaust gas recirculation rate to be sucked into the cylinder can be controlled accurately and with good followability. The target exhaust gas recirculation rate can be achieved satisfactorily not only during operation but also during transient operation, so that deterioration of operating performance, black smoke, particulates, fuel consumption, etc. can be suppressed within a predetermined range Performance and noise can be improved to the maximum.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is an overall configuration diagram according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration inside a control unit according to the embodiment.

FIG. 4 is a block diagram illustrating a target opening calculation unit of each valve in the above embodiment.

FIG. 5 is a block diagram illustrating a cylinder intake fresh air amount / collector internal pressure calculation unit and a volume efficiency estimation unit in the same embodiment.

FIG. 6 is a block diagram illustrating an EGR passage internal temperature calculation unit in the same embodiment.

FIG. 7 is a block diagram illustrating a target EGR amount calculation unit in the same embodiment.

FIG. 8 is a block diagram illustrating a lead processing operation unit in the embodiment.

FIG. 9 is a time chart showing a simulation result of a conventional device.

FIG. 10 is a time chart showing a simulation result in the first embodiment.

FIG. 11 is an overall configuration diagram according to a second embodiment.

FIG. 12 is an overall configuration diagram according to a third embodiment.

FIG. 13 is an overall configuration diagram according to a fourth embodiment.

FIG. 14 is an overall configuration diagram according to a fifth embodiment.

FIG. 15 is a diagram showing an example of a fuel injection amount setting map.

FIG. 16 is a diagram showing an example of a target EGR rate setting map.

FIG. 17 is a diagram showing an example of a volume efficiency setting map.

FIG. 18 is a diagram showing an example of a setting map of intake throttle valve opening and EGR valve opening.

FIG. 19 is a diagram showing an example of a Texhb setting map.

FIG. 20 is a diagram showing an example of the overall configuration of a conventional device.

FIG. 21 is a block diagram illustrating a configuration inside a control unit of a conventional device.

FIG. 22: Prediction E in the control unit of the conventional device
The block diagram explaining a GR rate operation part.

[Explanation of symbols]

1 internal combustion (diesel) engine 2 intake valve 3 fuel injection valve 4 exhaust valve 5 piston 6 collector 6A intake passage 7 exhaust manifold 7A exhaust passage 7B bypass passage 8 turbocharger 9 EGR passage 10a intake throttle valve 10b linear solenoid for driving intake throttle valve 11a EGR valve 11b EGR valve driving linear solenoid 12a Waste gate valve 15 Control unit 15a Target EGR rate setting unit 15b Fuel injection amount setting unit 15d EGR valve control unit 15e Intake throttle valve control unit 16 EGR valve / intake throttle target opening Calculation unit 16a Intake throttle target opening calculation unit 17 Cylinder intake fresh air amount / collector internal pressure calculation unit and volumetric efficiency estimation unit 17a Intake fresh air amount calculation unit to collector 17b Intake EGR amount calculation unit to collector 17c To cylinder Inhalation fresh air performance Computation unit 17d Intake EGR amount calculation unit to cylinder 17e Intake passage internal temperature calculation unit 17f EGR passage internal temperature calculation unit 17g Collector internal pressure calculation unit 17h Volume efficiency estimation unit 18 Target EGR rate calculation unit 18a Cylinder target EGR amount calculation unit 18b Advance processing operation unit 19 EGR valve target opening operation unit 20a Advance processing operation unit A 20b Advance processing operation unit B 20c Collector target EGR amount operation unit 21a Collector temperature operation unit 21d Exhaust temperature estimation unit 21e Exhaust passage temperature operation unit A 21f Exhaust passage temperature calculator B 21g EGR passage temperature calculator 22a Pressure sensor 22b Pressure sensor 23a Temperature sensor 23b Temperature sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location F02D 23/00 F02D 23/00 J 41/02 360 41/02 360

Claims (16)

[Claims] 1. A control device for an internal combustion engine, comprising: an exhaust gas recirculation passage that connects an exhaust passage and an intake passage of the internal combustion engine; and an exhaust gas recirculation valve that is interposed in the exhaust gas recirculation passage and controls an exhaust gas recirculation rate. In the cylinder, a cylinder intake fresh air amount detecting means for detecting the amount of fresh air drawn into the cylinder, a target exhaust gas recirculation rate setting means for setting a target exhaust gas recirculation rate according to the engine operating state, and Cylinder intake target exhaust gas recirculation amount calculation means for calculating a target exhaust gas recirculation amount to be sucked into a cylinder based on the new air amount and the target exhaust gas recirculation ratio, and the calculated cylinder intake target exhaust gas Intake passage intake target exhaust gas recirculation amount calculation for calculating the target exhaust gas recirculation amount to be sucked into the intake passage based on the recirculation amount and the dynamic characteristics of the exhaust gas recirculation gas from the exhaust recirculation valve to the engine intake valve Means and the calculated intake air flow Target intake air exhaust gas recirculation amount, pressure in intake passage, pressure in exhaust gas recirculation passage, exhaust density,
And an exhaust gas recirculation control means for driving and controlling the exhaust gas recirculation valve so as to obtain the calculated target opening degree. And a control device for an internal combustion engine, the control device comprising: 2. The dynamic characteristics of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve are determined by the engine speed, the intake passage volume of the portion filled with the exhaust gas recirculation gas, the stroke volume, and the volume efficiency. The control device for the internal combustion engine according to claim 1, wherein the control device is calculated based on 3. The cylinder intake fresh air amount detecting means inhales into the cylinder based on the amount of fresh air sucked into the intake passage and the dynamic characteristics of the sucked fresh air into the cylinder. The control device for an internal combustion engine according to claim 1 or 2, which is a means for obtaining a fresh air amount to be generated. 4. The dynamic characteristics of the fresh air to the cylinder include engine speed, intake passage volume, stroke volume, and volume efficiency.
The control device for the internal combustion engine according to claim 3, wherein the control device is calculated based on 5. The control device for an internal combustion engine according to claim 4, wherein the volumetric efficiency is estimated based on the engine speed and the pressure in the intake passage. 6. When an intake throttle valve is provided in an intake passage upstream of a communicating portion between the intake passage and the exhaust gas recirculation passage, the amount of fresh air sucked into the intake passage is the intake throttle valve opening and the intake air amount. 4. The control device for an internal combustion engine according to claim 3, wherein the control is performed based on the pressure in the intake passage downstream of the throttle valve, the pressure in the intake passage upstream of the intake throttle valve, and the atmospheric density. 7. The intake throttle valve opening is set on the basis of a target exhaust gas recirculation rate set by the target exhaust gas recirculation rate setting means, and the intake throttle valve is set so as to obtain the intake throttle valve opening. 7. The control device for an internal combustion engine according to claim 6, wherein the drive control is performed by the intake throttle valve control means. 8. The pressure in the intake passage downstream of the intake throttle valve is set to the temperature in the exhaust gas recirculation passage, the temperature in the intake passage upstream of the intake throttle valve, the engine speed, the volumetric efficiency, and 7. The calculation according to claim 6, wherein the calculated amount is based on the amount of fresh air taken in, the amount of exhaust gas recirculation taken into the cylinder, the stroke volume, the molecular weight of the atmosphere, and the molecular weight of the exhaust gas. 7. The control device for an internal combustion engine according to item 7. 9. When the internal combustion engine is provided with a supercharger, the temperature in the exhaust gas recirculation passage, the temperature in the intake passage upstream of the intake throttle valve, the amount of fresh air drawn into the cylinder, and the cylinder The exhaust gas recirculation amount sucked in, the pressure in the exhaust gas recirculation passage, the atmospheric pressure, the specific heat ratio of the exhaust gas, and the fuel injection amount, which are calculated based on the fuel injection amount. Control device for internal combustion engine. 10. When the internal combustion engine includes a supercharger, the temperature in the intake passage upstream of the intake throttle valve is such that the pressure in the intake passage upstream of the intake throttle valve, the atmospheric pressure, and the specific heat ratio of the atmosphere. The control device for the internal combustion engine according to claim 8 or 9, wherein the control device is calculated on the basis of the above, and the efficiency of the compressor of the supercharger. 11. The exhaust gas recirculation amount sucked into the cylinder is
11. The exhaust gas recirculation amount sucked into the intake passage is calculated based on the dynamic characteristic of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve, according to any one of claims 8 to 10. Of the internal combustion engine according to item 6. 12. A dynamic characteristic of the exhaust gas recirculation gas from the exhaust gas recirculation valve to the engine intake valve is based on an engine speed, an intake passage volume downstream of an intake throttle valve, a stroke volume, and a volume efficiency. The control device for an internal combustion engine according to claim 11, wherein the control device is calculated as follows. 13. The amount of exhaust gas recirculated into the intake passage is determined by the opening of the exhaust gas recirculation valve, the pressure in the intake passage downstream of the intake throttle valve, the pressure in the exhaust recirculation passage, and the exhaust density. The control device for an internal combustion engine according to claim 11 or claim 12, which is calculated based on the following. 14. The internal combustion engine according to claim 12 or 13, wherein the volumetric efficiency is estimated based on the engine speed and the pressure in the intake passage downstream of the intake throttle valve. Control device. 15. When the internal combustion engine is not provided with a supercharger, the pressure in the intake passage or the pressure in the intake passage upstream of the intake throttle valve is set as atmospheric pressure, and the temperature in the intake passage or the intake throttle valve upstream. The temperature in the intake passage is set to atmospheric temperature.
The control device for an internal combustion engine according to claim 14. 16. When the internal combustion engine is not equipped with a supercharger, the temperature in the exhaust gas recirculation passage is set to the atmospheric temperature, the amount of fresh air drawn into the cylinder, and the amount of exhaust gas recirculation taken into the cylinder. When,
The control device for an internal combustion engine according to claim 8, wherein the control device calculates the fuel injection amount based on the fuel injection amount.