JP7269104B2 - internal combustion engine controller - Google Patents

Description

The present invention relates to an internal combustion engine control system.

In recent years, automobile exhaust regulations have been strengthened. For example, in Europe, a test method called RDE (Real Driving Emission) is stipulated, and in this test method, exhaust components are evaluated under conditions equivalent to actual driving on the street. The RDE also stipulates tests under high altitude conditions and low temperature conditions of -7°C. Therefore, it is necessary to control the air-fuel ratio with high accuracy.

By the way, when starting the engine at an air temperature of -7°C, the engine is cold, so the density of the air increases compared to when the components of the combustion chamber are completely warmed up, and the amount of intake air increases. . Patent Literature 1 describes a method of correcting an estimated cylinder air amount based on a pre-matched cylinder temperature during transients.

JP-A-2000-265899

However, at the time of starting from low temperature conditions, the in-cylinder temperature is in a state different from the preliminarily adapted temperature, so in the invention described in Patent Document 1, the accuracy (estimation accuracy) of the estimated value of the air amount under low temperature conditions (estimation accuracy) is low. lower. There is also a method of correcting the amount of air using the cooling water temperature of the engine. However, with this method, if there is a discrepancy between the wall surface temperature of the cylinder member that actually comes into contact with the air and the temperature of the cooling water, the accuracy of estimating the amount of air decreases.

SUMMARY OF THE INVENTION An object of the present invention is to realize an internal combustion engine control apparatus capable of improving the accuracy of estimating an intake air amount in consideration of the above problems.

In order to solve the above problems and achieve the object of the present invention, an internal combustion engine control device of the present invention includes an air amount estimator, a fuel injection controller, and a wall surface temperature detector. The air quantity estimator estimates a cylinder air quantity, which is an air quantity in a cylinder of the internal combustion engine, based on the pressure of the intake pipe, the temperature of the intake pipe, the rotational speed of the internal combustion engine, or the phase of the variable valve. The fuel injection control section controls the fuel injection amount according to the in-cylinder air amount estimated by the air amount estimating section. The wall temperature detector detects the wall temperature of the cylinder of the internal combustion engine. The air amount estimating unit determines that the wall surface temperature of the cylinder is lower than a predetermined threshold when the temperature of the cooling water of the internal combustion engine is lower than a predetermined threshold temperature, and determines that the wall surface temperature of the cylinder is lower than the threshold temperature. By correcting the intake efficiency, correction is made so as to increase the in-cylinder air amount. Further, the air amount estimator learns a correction amount for the intake efficiency based on the measured pressure value of the intake pipe and the estimated pressure value of the intake pipe.

According to the internal combustion engine control device configured as described above , it is possible to improve the accuracy of estimating the intake air amount into the cylinder (in-cylinder air amount).

1 is a system configuration diagram of an internal combustion engine according to a first embodiment of the present invention; FIG. 1 is a system block diagram showing the configuration of an ECU according to a first embodiment of the invention; FIG. 4 is a flowchart showing an overview of intake efficiency correction control using cylinder wall surface temperature according to the first embodiment of the present invention; 4 is a flowchart showing an outline of reading an intake efficiency correction value using cylinder wall surface temperature according to the first embodiment of the present invention; 4 is a graph showing the relationship between cylinder wall surface temperature and intake efficiency correction value according to the first embodiment of the present invention. FIG. 3 is a control block diagram showing an overview of intake efficiency correction control using cylinder wall surface temperature according to the first embodiment of the present invention; FIG. 9 is a flow chart showing an overview of reading an intake efficiency correction value using cylinder wall surface temperature according to a second embodiment of the present invention; FIG. It is a graph which shows the relationship between cylinder wall surface temperature and an intake efficiency correction value which concerns on the 2nd Embodiment of this invention. FIG. 7 is a control block diagram showing an overview of intake efficiency correction control using cylinder wall surface temperature according to a second embodiment of the present invention; FIG. 11 is a flow chart showing an overview of intake efficiency correction control using cylinder wall surface temperature according to a third embodiment of the present invention; FIG. FIG. 9 is a control block diagram showing an outline of intake efficiency correction control using cylinder wall surface temperature according to a third embodiment of the present invention;

1. First Embodiment An internal combustion engine control apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG. In addition, the same code|symbol is attached|subjected to the member which is common in each figure.

[System Configuration of Internal Combustion Engine]
First, the system configuration of the internal combustion engine will be described with reference to FIG.
FIG. 1 is a system configuration diagram of an internal combustion engine according to the first embodiment.

The engine 100 shown in FIG. 1 is a spark ignition internal combustion engine. The engine 100 includes a mass flow meter 3 that measures the air flow rate at the inlet of the intake pipe 7, a supercharger compressor 4a that compresses the intake gas, a heat exchanger 5 that cools the compressed air, and a combustion chamber. 9 is equipped with a throttle valve 6 for adjusting the amount of gas taken in, and an intake pipe pressure sensor 8 . The mass flow meter 3 , compressor 4 a , heat exchanger 5 , throttle valve 6 and intake pipe pressure sensor 8 are arranged at appropriate positions in each intake pipe 7 .

The engine 100 also includes a fuel injection device 11 that injects fuel into the combustion chamber 9, a spark plug 12 that supplies ignition energy, a coolant temperature sensor 16 that detects coolant temperature, an intake valve 10a, and an exhaust valve. 10b. The combustion chamber 9 has an inlet through which the gas to be taken in passes and an exhaust port through which the gas after combustion is discharged. The intake valve 10 a is arranged at the intake port of the combustion chamber 9 , and the exhaust valve 10 b is arranged at the exhaust port of the combustion chamber 9 .

Further, the engine 100 includes a turbine 4b, a wastegate valve 4c, a three-way catalyst 13 for purifying harmful substances in exhaust gas, a three-way catalyst 14 installed under the floor of the vehicle, and an air-fuel ratio sensor 15. ing. The turbine 4b, the wastegate valve 4c, the three-way catalysts 13 and 14, and the air-fuel ratio sensor 15 are arranged at appropriate positions in the exhaust pipe 17, respectively.

The turbine 4b uses the energy of the exhaust gas to drive the compressor 4a, and the wastegate valve 4c releases the pressure applied to the turbine 4b. The air-fuel ratio sensor 15 is one aspect of an air-fuel ratio detector, and detects the air-fuel ratio of the exhaust gas on the upstream side of the three-way catalyst 13 . Note that the air-fuel ratio sensor 15 may be an oxygen concentration sensor that detects the oxygen concentration in the exhaust gas.

An ECU (Engine Control Unit) 1 controls an engine 100 . A detection signal Ss3 obtained from the mass flow meter 3, a detection signal Ss6 obtained from the throttle valve 6, and a signal Ss8 obtained from the intake pipe pressure sensor 8 are sent to the ECU1. A detection signal Ss15 obtained from the air-fuel ratio sensor 15 and a detection signal Ss16 obtained from the cooling water temperature sensor 16 are also sent to the ECU 1 . Further, the ECU 1 is sent an output signal Ss2 obtained from an accelerator opening sensor 2 that detects the depression amount of the accelerator pedal, that is, the accelerator opening.

The ECU 1 calculates the required torque based on the output signal Ss2 of the accelerator opening sensor 2 and various sensor signals. That is, accelerator opening sensor 2 is used as a required torque detection sensor that detects the required torque to engine 100 .

The ECU 1 also calculates the opening of the throttle valve 6, the injection pulse period and injection start timing of the fuel injection device 11, and the ignition timing of the spark plug 12 based on the operating state of the engine 100 obtained from the outputs of various sensors. . Furthermore, the ECU 1 calculates the opening/closing timing of the intake valve 10a and the exhaust valve 10b, the opening degree of the waste gate valve 4c, and the like, based on the operating state of the engine 100 obtained from the outputs of various sensors.

The ECU 1 determines a fuel amount (target injection amount) according to the intake air amount (in-cylinder air amount) into the combustion chamber 9, and calculates a fuel injection pulse period according to the fuel amount. The fuel injection pulse period calculated by the ECU 1 is converted into a fuel injection device drive signal Ds 11 and sent to the fuel injection device 11 . The opening degree of the throttle valve 6 calculated by the ECU 1 is sent to the throttle valve 6 as a throttle valve driving signal Ds6.

An intake valve drive signal Ds10a calculated by the ECU 1 is sent to the intake valve 10a, and an exhaust valve drive signal Ds10b is sent to the exhaust valve 10b. Similarly, the fuel injection device drive signal Ds11 calculated by the ECU 1 is sent to the fuel injection device 11, and the spark plug drive signal Ds12 is sent to the spark plug 12.

In the engine 100 having such a configuration, the fuel injection device 11 injects fuel into the gas taken into the combustion chamber 9 from the intake pipe 7 through the intake valve 10a to generate an air-fuel mixture. The generated air-fuel mixture is combusted by a spark generated from the ignition plug 12 at a predetermined ignition timing, and the combustion pressure pushes down the piston to generate driving force. The exhaust after combustion is sent to the three-way catalyst 13 through the exhaust valve 10b, the exhaust pipe 17, and the turbine 4b, where noxious substances such as NOx, CO, and HC components are purified.

[Internal configuration of ECU]
Next, the internal configuration of the ECU 1 that controls the engine 100 will be described with reference to FIG.
FIG. 2 is a system block diagram showing the configuration of the ECU according to the first embodiment.

As shown in FIG. 2, the ECU 1 is a specific example of an internal combustion engine control device, and includes an input circuit 30a, an input/output port 30b, a RAM (Random Access Memory) 30c, and a ROM (Read Only Memory). 30d and a CPU (Central Processing Unit) 30e. The ECU 1 also has a throttle drive circuit 30f, a VTC (variable timing camshaft) drive circuit 30g, a fuel injection device drive circuit 30h, an ignition output circuit 30i, and a waste gate valve drive circuit 30j.

Output signals (Ss2, Ss3, Ss6, Ss8, Ss10a, Ss10b, Ss15, Ss16) are input. The signals input to the input circuit 30a are not limited to these, and outputs from other various sensors may be input.

The input circuit 30a performs signal processing such as noise removal on the input signal and sends the processed signal to the input port in the input/output port 30b. At this time, among the input signals sent to the input circuit 30a, the analog signal is converted into a digital signal by the A/D converter provided in the input circuit 30a. The value of the input signal sent to the input/output port 30b is stored in the RAM 30c.

The ROM 30d stores a control program describing the contents of various arithmetic processing executed by the CPU 30e, MAPs and data tables used in each processing, and the like. The RAM 30c is provided with a storage area for storing the values input to the input ports of the input/output port 30b and the values representing the manipulated variables of the actuators calculated according to the control program. Also, the value representing the operation amount of each actuator stored in the RAM 30c is sent to the output port of the input/output port 30b.

The CPU 30e represents a specific example of an air amount estimator according to the present invention. This CPU 30e controls the amount of air in the combustion chamber 9 based on the pressure of the intake pipe 7, the temperature of the intake pipe 7, the rotational speed of the engine 100, or the phases of the variable valves (intake valve 10a, exhaust valve 10b). An internal air amount (cylinder intake air amount DG_CYL to be described later) is estimated.

A throttle drive circuit 30 f controls the throttle valve 6 . That is, the throttle valve drive signal Ds6 set to the output port of the input/output port 30b is sent to the motor that drives the throttle valve 6 via the throttle drive circuit 30f.

The VTC drive circuit 30g controls the intake valve 10a and the exhaust valve 10b. That is, the intake valve drive signal Ds10a set to the output port of the input/output port 30b is sent to the motor that drives the intake valve 10a through the VTC drive circuit 30g. Also, the exhaust valve drive signal Ds10b set to the output port of the input/output port 30b is sent to the motor that drives the exhaust valve 10b via the VTC drive circuit 30g.

The fuel injection device drive circuit 30h represents a specific example of the fuel injection control section according to the present invention, and controls the fuel injection device 11. FIG. That is, the fuel injector drive signal Ds11 set to the output port of the input/output port 30b is amplified to energy sufficient to drive the fuel injector 11 by the fuel injector drive circuit 30h, and the fuel injector 11 supplied.

The ignition output circuit 30 i controls the ignition plug 12 . That is, the ignition plug driving signal Ds12 set to the output port of the input/output port 30b is amplified to a sufficient energy required for ignition by the ignition output circuit 30i and supplied to the ignition plug 12. FIG.

The wastegate valve drive circuit 30j controls the wastegate valve 4c. That is, the wastegate valve drive signal Ds4c set to the output port of the input/output port 30b is sent to the motor that drives the wastegate valve 4c through the wastegate valve drive circuit 30j.

In addition, although the ECU 1 of the present embodiment includes the drive circuit described above in the ECU 1, the present invention is not limited to this. As an ECU according to the present invention, any or all of the drive circuits described above may be provided outside the ECU, and signals may be sent to the drive circuits provided outside.

[Intake efficiency correction control by ECU]
Next, the intake efficiency correction control by the ECU 1 will be described with reference to FIG.
FIG. 3 is a flowchart showing an outline of intake efficiency correction control according to the first embodiment.

First, the CPU 30e of the ECU 1 determines whether or not the cooling water temperature TW is lower than a preset threshold temperature CTWCOR (S301). The threshold temperature CTWCOR is determined based on past data such as cooling water temperature, intake efficiency, and fuel injection amount.

When it is determined in S301 that the cooling water temperature TW is not less than the threshold temperature CTWCOR (when S301 determines YES), the CPU 30e adjusts the intake efficiency according to the wall surface temperature of the combustion chamber 9 (hereinafter referred to as "cylinder wall surface temperature"). It is determined that the execution conditions for correction are not satisfied, and the wall surface temperature influence correction value KETATWALL is set to "1" (S302). That is, when determining that the cooling water temperature TW is not less than the threshold temperature CTWCOR, the CPU 30e determines that the cylinder wall surface temperature is equal to or higher than the threshold, and determines that the intake efficiency correction execution condition is not satisfied. After the processing of S302, the CPU 30e performs the processing of S305, which will be described later.

On the other hand, when it is determined in S301 that the cooling water temperature TW is less than the threshold temperature CTWCOR (if the determination in S301 is YES), the CPU 30e determines that the condition for performing intake efficiency correction according to the cylinder wall surface temperature is satisfied, and A wall surface temperature TCYLWALL is calculated (S303). That is, when determining that the cooling water temperature TW is less than the threshold temperature CTWCOR, the CPU 30e determines that the cylinder wall surface temperature is lower than the threshold, and determines that the intake efficiency correction execution condition is satisfied.

In the process of S303, the CPU 30e calculates the cylinder wall surface temperature TCYLWALL from at least the coolant temperature, fuel injection amount, cylinder air amount, ignition timing, and the like. For example, in the combustion operation state of the engine 100, the CPU 30e calculates the cylinder wall temperature TCYLWALL based on the cooling water temperature, the integrated value of the in-cylinder air amount (the integrated value of the fuel injection amount), the engine load, the engine rotation speed, and the like. .

Next, the CPU 30e uses the cylinder wall surface temperature TCYLWALL as an argument and reads out the wall surface temperature influence correction value KETATWALL from the table stored in the ROM 30d (S304). The process of reading the wall surface temperature influence correction value KETATWALL will be described later with reference to FIG.

After the processing of S302 or S304, the CPU 30e calculates post-warm-up intake efficiency INTKEF_VTC (S305). The post-warm-up intake efficiency INTKEF_VTC is calculated by multiplying the basic intake efficiency read out from a table whose arguments are the intake pipe pressure estimate and the engine speed by the change rate of the intake efficiency depending on the VTC phase.

Next, the CPU 30e calculates the air intake efficiency INTKEF_TW after wall surface temperature effect correction (S306). The intake efficiency INTKEF_TW after wall surface temperature influence correction is calculated by the following equation (Equation 1).

INTKEF_TW=INTKEF_VTC×KETATWALL . . . Equation 1

Next, the CPU 30e calculates a cylinder intake air amount DG_CYL, which is the amount of air taken into the combustion chamber 9 (in-cylinder air amount) (S307). In this process, the CPU 30e controls the wall temperature influence corrected intake efficiency INTKEF_TW, the engine speed NE, the cylinder stroke volume VCYL, the number of cylinders NCYL, the intake pipe pressure estimated value P_IMANI, the intake pipe temperature T_IMANI, and the constant RAIR. is used to calculate the cylinder intake air amount DG_CYL by the following equation (Equation 2).

DG_CYL=INTKEF_TW×NE×VCYL×NCYL/120×P_IMANI/(RAIR×T_IMANI) Equation 2

In the present embodiment, when the cooling water temperature TW is less than the threshold temperature CTWCOR, the wall surface temperature effect correction value KETATWALL is read to calculate the air intake efficiency INTKEF_TW after wall surface temperature effect correction. However, as the intake efficiency correction control according to the present invention, when the cylinder wall surface temperature TCYLWALL is less than a predetermined value (set value), the surface temperature influence correction value KETATWALL is read and the intake efficiency INTKEF_TW after wall surface temperature influence correction is calculated. You may make it calculate.

[Wall surface temperature effect correction value reading process]
Next, referring to FIG. 4, the reading process of the wall surface temperature influence correction value performed in S304 of the intake efficiency correction control by the ECU 1 will be described.
FIG. 4 is a flow chart showing an outline of reading the intake efficiency correction value according to the first embodiment.

First, the CPU 30e of the ECU 1 reads out the non-supercharging wall surface temperature effect correction value KETATWALLP from the non-supercharging wall surface temperature effect correction value table stored in the ROM 30d (S401). The argument of the non-supercharging wall surface temperature influence correction value table is the cylinder wall surface temperature TCYLTWALL calculated in step S303 of the intake efficiency correction control (see FIG. 3).

Next, the CPU 30e reads out the supercharging wall surface temperature effect correction value KETATWALLB from the supercharging wall surface temperature effect correction value table stored in the ROM 30d (S402). The argument of the supercharging wall temperature influence correction value table is the cylinder wall temperature TCYLTWALL calculated in step S303 of the intake efficiency correction control (see FIG. 3).

Next, the CPU 30e determines whether the engine 100 is currently in a non-supercharging state (S403). In the processing of S403, the CPU 30e determines non-supercharging when the intake pipe pressure estimated value P_IMANI is less than the atmospheric pressure P_ATM.

When it is determined in S403 that the engine 100 is currently in the non-supercharging state (if the determination in S403 is YES), the CPU 30e determines the non-supercharging wall temperature influence correction value KETATWALLP as the wall surface temperature influence correction value KETATWALL. (S404). After that, the CPU 30e ends the wall surface temperature influence correction value reading process, and shifts the process to S305 of the intake efficiency correction control (see FIG. 3).

On the other hand, when it is determined in S403 that the engine 100 is not currently in the non-supercharging state (if the determination in S403 is NO), that is, when it is determined that the engine 100 is in the supercharging state, the CPU 30e performs supercharging wall temperature effect correction. The value KETATWALLB is determined as the wall surface temperature effect correction value KETATWALL (S405). After that, the CPU 30e ends the wall surface temperature influence correction value reading process, and shifts the process to S305 of the intake efficiency correction control (see FIG. 3).

FIG. 5 is a graph showing the relationship between cylinder wall surface temperature and intake efficiency correction value according to the first embodiment. In the non-supercharged state, the change rate of the cylinder wall surface temperature is greater than in the supercharged state. Therefore, as shown in FIG. 5, the slope of the straight line indicating the relationship between the cylinder wall surface temperature and the wall surface temperature effect correction device differs between the non-supercharging state and the supercharging state.

Therefore, in the present embodiment, the correction coefficients are made different in the two regions of the non-supercharging state and the supercharging state, and the wall surface temperature effect correction value table for the non-supercharging state (non-supercharging wall temperature effect correction value table ) and a wall surface temperature effect correction value table in supercharging state (supercharging wall surface temperature effect correction value table). As a result, the wall surface temperature effect correction value can be changed according to the non-supercharging state and the supercharging state, and the error in the cylinder air amount calculated using the wall surface temperature effect correction value can be reduced.

FIG. 6 is a control block diagram showing an overview of intake efficiency correction control using the cylinder wall surface temperature according to the first embodiment. As shown in FIG. 6, in the intake efficiency correction control according to the first embodiment, the post-warm-up intake efficiency INTKEF_VTC is calculated using the engine speed NE, the intake pipe pressure estimated value P_IMANI, and the VTC influence term. The VTC influence term is the rate of change of the intake efficiency due to the VTC phase.

Further, in the intake efficiency correction control according to the first embodiment, the cylinder wall surface temperature TCYLWALL is estimated from the cooling water temperature, the fuel injection amount, and the like. Then, using the cylinder wall surface temperature TCYLWALL as an argument, the wall surface temperature effect correction value KETATWALL is read from the non-supercharging wall surface temperature effect correction value table or the supercharging wall surface temperature effect correction value table.

Furthermore, in the intake efficiency correction control according to the first embodiment, if the cooling water temperature TW is less than the threshold temperature CTWCOR, the value read from the wall surface temperature effect correction value table is used as the wall surface temperature effect correction value KETATWALL. On the other hand, if the cooling water temperature TW is less than the threshold temperature CTWCOR, the wall surface temperature influence correction value KETATWALL is set to "1".

Then, the after-warm-up intake efficiency INTKEF_VTC is multiplied by the wall surface temperature effect correction value KETATWALL to calculate the wall surface temperature effect corrected intake efficiency INTKEF_TW. As a result, when the wall surface temperature influence correction value KETATWALL is not set to "1", the in-cylinder air amount (cylinder intake air amount DG_CYL) is estimated so as to increase according to the cylinder wall surface temperature TCYLWALL.

Thus, in the intake efficiency correction control according to the first embodiment, the cylinder wall surface temperature is estimated, and the increase in air density caused by cooling by the cylinder wall surface is corrected. As a result, it is possible to reduce the estimation error of the in-cylinder air amount. That is, it is possible to improve the estimation accuracy of the in-cylinder air amount.

Furthermore, the wall surface temperature influence correction value is changed in the supercharging region in which the proportion of the cylinder air amount contacting the cylinder wall surface is large and the non-supercharging region in which the proportion of the cylinder internal air quantity contacting the cylinder wall surface is small. As a result, it is possible to reduce the estimation error of the in-cylinder air amount calculated using the wall surface temperature influence correction value.

2. Second Embodiment Next, an internal combustion engine control system according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. FIG. In addition, the same code|symbol is attached|subjected to the member which is common in each figure.

The internal combustion engine control device according to the second embodiment has the same configuration as the internal combustion engine control device according to the first embodiment, except for the process of reading the wall surface temperature influence correction value. Therefore, here, the reading process of the wall surface temperature effect correction value according to the second embodiment will be described, and the description of other parts common to the first embodiment will be omitted.

[Wall surface temperature effect correction value reading process]
FIG. 7 is a flow chart showing an outline of reading the intake efficiency correction value according to the second embodiment. The CPU 30e of the ECU 1 selects the wall surface temperature influence correction value table to be used based on the intake pipe pressure estimated value P_IMANI (S701).

Next, the CPU 30e uses the cylinder wall surface temperature TCYLWALL as an argument to read out the wall surface temperature effect correction value KETATWALL from the wall surface temperature effect correction value table selected in S701 (S702). The argument of the wall surface temperature influence correction value table is the cylinder wall surface temperature TCYLTWALL calculated in step S303 of the intake efficiency correction control (see FIG. 3). After that, the CPU 30e ends the wall surface temperature influence correction value reading process, and shifts the process to S305 of the intake efficiency correction control (see FIG. 3).

FIG. 8 is a graph showing the relationship between the cylinder wall surface temperature and the intake efficiency correction value according to the second embodiment. As shown in FIG. 8, the slope of the straight line indicating the relationship between the cylinder wall surface temperature and the wall surface temperature influence correction value varies depending on the engine load value (intake pressure of engine 100). For example, the lower the intake pressure of the engine 100, the greater the slope of the straight line indicating the relationship between the cylinder wall surface temperature and the wall surface temperature influence correction value. In addition, when the supercharging conditions are the same, the slopes are almost the same.

Therefore, in the second embodiment, a plurality of wall surface temperature effect correction value tables are provided according to the intake pipe pressure, and the wall surface temperature effect correction value table to be used is selected based on the intake pipe pressure. In this embodiment, the estimated intake pipe pressure value P_IMANI is used as the value of the engine load. An engine output or the like may be applied.

FIG. 9 is a control block diagram showing an outline of intake efficiency correction control using cylinder wall surface temperature according to the second embodiment. As shown in FIG. 9, in the intake efficiency correction control according to the second embodiment, the post-warm-up intake efficiency INTKEF_VTC is calculated using the engine speed NE, the intake pipe pressure estimated value P_IMANI, and the VTC influence term. The VTC influence term is the rate of change of the intake efficiency due to the VTC phase.

Further, in the intake efficiency correction control according to the second embodiment, the cylinder wall surface temperature TCYLWALL is estimated from the cooling water temperature, the fuel injection amount, and the like. Then, the wall surface temperature effect correction value table to be used is selected based on the intake pipe pressure estimated value P_IMANI, and the wall surface temperature effect correction value KETATWALL is read using the cylinder wall surface temperature TCYLWALL as an argument. The wall surface temperature influence correction value table according to the second embodiment may be a table using two variables, the intake pipe pressure estimated value P_IMANI and the cylinder wall surface temperature TCYLWALL, as arguments.

Furthermore, in the intake efficiency correction control according to the second embodiment, if the cooling water temperature TW is less than the threshold temperature CTWCOR, the value read from the wall surface temperature effect correction value table is used as the wall surface temperature effect correction value KETATWALL. On the other hand, if the cooling water temperature TW is less than the threshold temperature CTWCOR, the wall surface temperature influence correction value KETATWALL is set to "1".

Then, the after-warm-up intake efficiency INTKEF_VTC is multiplied by the wall surface temperature effect correction value KETATWALL to calculate the wall surface temperature effect corrected intake efficiency INTKEF_TW. As a result, when the wall surface temperature influence correction value KETATWALL is not set to "1", the in-cylinder air amount (cylinder intake air amount DG_CYL) is estimated so as to increase according to the cylinder wall surface temperature TCYLWALL.

In the intake efficiency correction control according to the second embodiment, different intake air temperature correction values are read out for supercharging and non-supercharging in the intake efficiency correction control according to the first embodiment. The intake manifold pressure, which has a higher correlation with the exchange rate, is further subdivided and read out. As a result, the estimation error of the in-cylinder air amount calculated using the wall surface temperature influence correction value can be reduced more than in the first embodiment.

3. Third Embodiment Next, an internal combustion engine control system according to a third embodiment of the present invention will be described with reference to FIGS. 10 and 11. FIG. In addition, the same code|symbol is attached|subjected to the member which is common in each figure.

The internal combustion engine control system according to the third embodiment has the same configuration as the internal combustion engine control system according to the first embodiment, except for the intake efficiency correction control. Therefore, here, the intake efficiency correction control according to the third embodiment will be described, and the description of other parts common to the first embodiment will be omitted.

[Intake efficiency correction control by ECU]
FIG. 10 is a flowchart showing an overview of intake efficiency correction control according to the third embodiment.
When performing intake efficiency correction, the effect of correction may be reduced due to individual differences in engines and errors in table setting values. Therefore, the intake efficiency correction control according to the third embodiment has a learning function for maintaining the effect of the intake efficiency correction.

First, the CPU 30e of the ECU 1 determines whether or not the cooling water temperature TW is lower than a preset threshold temperature CTWCOR (S1001). When it is determined in S1001 that the cooling water temperature TW is not less than the threshold temperature CTWCOR (if the determination in S1001 is NO), the CPU 30e determines that the condition for performing intake efficiency correction according to the cylinder wall surface temperature is not satisfied. The post-influence-learning correction value KETATWALL2 is set to "1" (S1002). After the processing of S1002, the CPU 30e performs the processing of S1011, which will be described later.

On the other hand, when it is determined in S1001 that the cooling water temperature TW is less than the threshold temperature CTWCOR (if the determination in S1001 is YES), the CPU 30e determines that the conditions for performing intake efficiency correction according to the cylinder wall surface temperature are satisfied. A wall surface temperature TCYLWALL is calculated (S1003). In the process of S1003, the CPU 30e calculates the cylinder wall surface temperature TCYLWALL from at least the coolant temperature, fuel injection amount, cylinder air amount, ignition timing, and the like.

Next, the CPU 30e uses the cylinder wall surface temperature TCYLWALL as an argument and reads out the wall surface temperature influence correction value KETATWALL from the table stored in the ROM 30d (S1004). The process of reading the wall surface temperature effect correction value KETATWALL is the same as that described with reference to FIG. Note that the process of reading the wall surface temperature influence correction value KETATWALL may be the one described with reference to FIG.

Next, the CPU 30e calculates an intake pipe pressure estimation error PMERROR using the following equation (Equation 3) (S1005). That is, the intake pipe pressure estimation error PMERROR is calculated by dividing the intake pipe pressure estimation value P_IMANI by the intake pipe pressure measurement value PMTPBI.

PMERROR=P_IMANI/PMTPBI Expression 3

Next, the CPU 30e determines whether or not the intake pipe pressure estimation error PMERROR is less than the intake pipe pressure estimation error threshold CPME (S1006). The intake pipe pressure estimation error threshold CPME is determined based on data such as past intake pipe pressure estimation values, intake pipe pressure measurement values, intake efficiency, and fuel injection amount.

When it is determined in S1006 that the intake pipe pressure estimation error PMERROR is not less than the intake pipe pressure estimation error threshold value CPME (if the determination in S1006 is NO), the CPU 30e updates the intake pipe pressure estimation error PMERROR as the correction learning value KEWL ( S1007). After the processing of S1007, the CPU 30e performs the processing of S1009, which will be described later.

On the other hand, when it is determined in S1006 that the intake pipe pressure estimation error PMERROR is less than the intake pipe pressure estimation error threshold CPME (if the determination in S1006 is YES), the CPU 30e takes the cylinder wall surface temperature TCYLWALL as an argument and stores it in the ROM 30d. The corrected learning value KEWL is read out from the table (S1008).

After the processing of S1007 or S1008, the CPU 30e calculates the correction value KETATWALL2 after wall surface temperature influence learning using the following equation (Equation 4) (S1009). That is, the correction value KETATWALL2 after wall temperature influence learning is calculated by multiplying the wall temperature influence correction value KETATWALL by the correction learning value KEWL.

KETATWALL2=KETATWALL×KEWL . . . 4

Next, CPU 30e calculates post-warm-up intake efficiency INTKEF_VTC (S1010). The post-warm-up intake efficiency INTKEF_VTC is calculated by multiplying the basic intake efficiency read out from a table whose arguments are the intake pipe pressure estimate and the engine speed by the change rate of the intake efficiency depending on the VTC phase.

Next, the CPU 30e calculates the air intake efficiency INTKEF_TW after wall surface temperature effect correction (S1011). The intake efficiency INTKEF_TW after wall surface temperature influence correction is calculated by the following equation (Equation 5). That is, the post-wall temperature effect corrected intake efficiency INTKEF_TW is calculated by multiplying the post-warm-up intake efficiency INTKEF_VTC by the post-wall temperature effect learning correction value KETATWALL2.

INTKEF_TW=INTKEF_VTC×KETATWALL2 Equation 5

Next, the CPU 30e calculates the cylinder intake air amount DG_CYL, which is the amount of air taken into the combustion chamber 9 (S1012). In this process, the CPU 30e controls the wall temperature influence corrected intake efficiency INTKEF_TW, the engine speed NE, the cylinder stroke volume VCYL, the number of cylinders NCYL, the intake pipe pressure estimated value P_IMANI, the intake pipe temperature T_IMANI, and the constant RAIR. is used to calculate the cylinder intake air amount DG_CYL by the above-mentioned equation (2).

FIG. 11 is a control block diagram showing an outline of intake efficiency correction control using cylinder wall surface temperature according to the third embodiment. As shown in FIG. 11, calculation of the post-warm-up intake efficiency INTKEF_VTC in the intake efficiency correction control according to the third embodiment is the same as in the first and second embodiments.

In the intake efficiency correction control according to the third embodiment, the intake pipe pressure estimation value P_IMANI is divided by the intake pipe pressure measurement value PMTPBI to calculate the intake pipe pressure estimation error PMERROR. Then, if the intake pipe pressure estimation error PMERROR is equal to or greater than the intake pipe pressure estimation error threshold CPME (hereinafter referred to as "threshold CPME"), the intake pipe pressure estimation error PMERROR is updated as the correction learning value KEWL. On the other hand, if the intake pipe pressure estimation error PMERROR is less than the threshold CPME, the correction learning value KEWL is read from the cylinder wall surface temperature TCYLWALL.

Further, in the intake efficiency correction control according to the third embodiment, KETATWALL is set to "1" unless the cooling water temperature TW is less than the threshold temperature CTWCOR. On the other hand, if the cooling water temperature TW is less than the threshold temperature CTWCOR, the value read from the wall surface temperature effect correction value table is used as the wall surface temperature effect correction value KETATWALL.

Then, the wall surface temperature effect correction value KETATWALL and the correction learned value KEWL are multiplied to calculate the wall surface temperature effect post-learning correction value KETATWALL2. After that, the after-warm-up intake efficiency INTKEF_VTC is multiplied by the correction value KETATWALL2 after wall temperature effect learning to calculate the post-wall temperature effect corrected intake efficiency INTKEF_TW. As a result, when the correction value KETATWALL2 after wall surface temperature influence learning is not set to "1", the cylinder air amount (cylinder intake air amount DG_CYL) is estimated so as to increase according to the cylinder wall surface temperature TCYLWALL.

As described above, in the intake efficiency correction control according to the third embodiment, the cylinder pressure is calculated based on the difference between the intake pipe pressure estimated value calculated based on the mass flow meter 3 and the cylinder air amount estimated value, and the intake pipe pressure measurement value. To correct the intake efficiency when the wall surface temperature is lower than a predetermined temperature. As a result, it is possible to correct the difference in heat exchange rate between the cylinder wall surface and the air due to machine differences and deterioration over time.

4. Summary As described above, the internal combustion engine control device of the first to third embodiments described above includes an air amount estimator (CPU 30e), a fuel injection controller (fuel injection device drive circuit 30h), a wall surface A temperature detection unit (CPU 30e for processing S303 or S1003) is provided. The air amount estimator determines the internal combustion rate based on the pressure of the intake pipe (intake pipe 7), the temperature of the intake pipe, the rotation speed of the internal combustion engine (engine 100), or the phase of the variable valve (intake valve 10a, exhaust valve 10b). The in-cylinder air amount (cylinder intake air amount DG_CYL), which is the amount of air in the cylinder (combustion chamber 9) of the engine, is estimated. The fuel injection control section controls the fuel injection amount according to the in-cylinder air amount estimated by the air amount estimating section. Then, the air amount estimator corrects the in-cylinder air amount so as to increase in accordance with the wall surface temperature of the cylinder (cylinder wall surface temperature TCYLWALL). As a result, it is possible to correct an increase in the air density caused by cooling by the wall surface of the cylinder (combustion chamber 9), and to reduce the estimation error of the in-cylinder air amount into the cylinder. That is, it is possible to improve the estimation accuracy of the in-cylinder air amount into the cylinder.

Further, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the first to third embodiments described above corrects the intake efficiency when the cylinder wall surface temperature (cylinder wall surface temperature TCYLWALL) is lower than a predetermined threshold. (using the air intake efficiency INTKEF_TW after wall surface temperature influence correction), the in-cylinder air amount (cylinder intake air amount DG_CYL) is estimated. As a result, it is possible to correct an increase in the air density caused by cooling by the wall surface of the cylinder (combustion chamber 9), and to reduce the estimation error of the in-cylinder air amount into the cylinder. That is, it is possible to improve the estimation accuracy of the in-cylinder air amount into the cylinder.

Further, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the first to third embodiments described above determines that the cooling water temperature of the internal combustion engine (detection result of the cooling water temperature sensor 16) is set to a set value (threshold temperature CTWCOR ), it is determined that the wall surface temperature of the cylinder (cylinder wall surface temperature TCYLWALL) is lower than a predetermined threshold. This makes it possible to easily determine whether or not to correct the intake efficiency.

Further, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the above-described first to third embodiments has at least a different correction coefficient depending on whether it is supercharged or not (supercharged wall temperature influence correction value KETATWALLB, The in-cylinder air amount (cylinder intake air amount DG_CYL) is estimated based on the non-supercharging wall surface temperature influence correction value KETATWALLP). As a result, the correction coefficient can be changed according to the ratio of the in-cylinder air amount that contacts the wall surface of the cylinder (combustion chamber 9), and the estimation error of the in-cylinder air amount can be reduced.

Further, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the second embodiment described above has a correction coefficient ( The cylinder air amount (cylinder intake air amount DG_CYL) is estimated based on the wall surface temperature effect correction value KETATWALL read from the wall surface temperature effect correction value table selected based on the intake pipe pressure estimated value P_IMANI. As a result, the correction coefficient can be subdivided according to the load level of the internal combustion engine, and the estimation error of the in-cylinder air amount can be further reduced.

Further, the load level of the internal combustion engine according to the internal combustion engine control apparatus of the second embodiment described above is assumed to be the intake pipe pressure estimated value (intake pipe pressure estimated value P_IMANI). As a result, the correction coefficient can be subdivided according to the intake pipe pressure, which has a higher (relatively high) correlation of the heat exchange rate with the wall surface of the cylinder (combustion chamber 9), and the estimation error of the cylinder air amount can be reduced. can be reduced.

In addition, the air amount estimator (CPU 30e) in the internal combustion engine control system of the second embodiment described above calculates an intake pipe pressure estimated value (intake pipe pressure estimated value P_IMANI) and a cylinder wall surface temperature (cylinder wall surface temperature TCYLWALL). A correction value (wall surface temperature effect correction value KETATWALL) for estimating the in-cylinder air amount (cylinder intake air amount DG_CYL) is acquired from a table having two variables as arguments. As a result, there is no need to provide a plurality of tables corresponding to the pressure estimation values of the intake pipe, and the amount of data required for correcting the intake efficiency can be reduced.

In addition, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the third embodiment described above calculates an intake pipe pressure measurement value (intake pipe pressure measurement value PMTPBI) and an intake pipe pressure estimation value (intake pipe pressure Based on the estimated value P_IMANI), the intake efficiency correction amount (correction learning value KEWL) is learned. This makes it possible to correct the difference in heat exchange rate between the wall surface of the cylinder (combustion chamber 9) and the air due to instrumental differences and deterioration over time.

In addition, the air amount estimator (CPU 30e) in the internal combustion engine control apparatus of the third embodiment described above provides an estimated intake pipe pressure value (estimated intake pipe pressure value P_IMANI) (intake pipe pressure estimation error PMERROR) is equal to or greater than a predetermined threshold (intake pipe pressure estimation error threshold CPME), the ratio is associated with the cylinder wall temperature (cylinder wall temperature TCYLWALL). It is stored as a learned value (corrected learned value KEWL). Then, the intake efficiency is corrected based on the learned value. This makes it possible to correct the difference in heat exchange rate between the wall surface of the cylinder (combustion chamber 9) and the air due to instrumental differences and deterioration over time.

Further, the wall surface temperature detection unit (CPU 30e that performs the processing of S303 or S1003) in the internal combustion engine control apparatus of the first to third embodiments described above detects at least the cooling water temperature of the internal combustion engine, the fuel injection amount, and the in-cylinder air amount. Alternatively, the cylinder wall temperature (cylinder wall temperature TCYLWALL) is estimated based on the ignition timing. As a result, the wall surface temperature of the cylinder can be estimated based on the coolant temperature and the like, and the in-cylinder air amount can be estimated according to the estimated wall surface temperature of the cylinder.

The embodiment of the internal combustion engine control device of the present invention has been described above, including its effects. However, the internal combustion engine control system of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention described in the claims.

Also, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

For example, in the above-described first embodiment, a non-supercharging wall surface temperature effect correction value table and a supercharging wall surface temperature effect correction value table are provided. However, the internal combustion engine control device according to the present invention may have a configuration in which a table having two parameters of supercharging/non-supercharging and cylinder wall surface temperature TCYLWALL as arguments is provided.

Moreover, the present invention described in the first to third embodiments can be applied to a hybrid system of an internal combustion engine and a motor.

REFERENCE SIGNS LIST 1 ECU (internal combustion engine control device) 2 accelerator opening sensor 3 mass flow meter 4a compressor 4b turbine 4c waste gate valve 5 heat exchanger 6 throttle valve 7 Intake pipe 8 Intake pipe pressure sensor 9 Combustion chamber (cylinder) 10a Intake valve 10b Exhaust valve 11 Fuel injection device 12 Spark plug 13, 14 Three-way catalyst 15 Air-fuel ratio sensor 16 Coolant temperature sensor 17 Exhaust pipe 30a Input circuit 30b Input/output port 30c RAM 30d ROM 30e CPU 30f Throttle drive circuit 30g VTC drive circuit , 30h... Fuel injection device drive circuit 30i... Ignition output circuit 30j... Waste gate valve drive circuit 100... Engine

Claims (6)

an air amount estimating unit that estimates a cylinder air amount, which is an air amount in a cylinder of the internal combustion engine, based on the pressure of the intake pipe, the temperature of the intake pipe, the rotational speed of the internal combustion engine, or the phase of the variable valve;
a fuel injection control unit that controls a fuel injection amount according to the in-cylinder air amount estimated by the air amount estimation unit;
a wall temperature detection unit that detects the wall surface temperature of the cylinder of the internal combustion engine,
The air amount estimating unit determines that the wall surface temperature of the cylinder is lower than a predetermined threshold when the cooling water temperature of the internal combustion engine is lower than a predetermined threshold temperature, and determines that the wall surface temperature of the cylinder is lower than the threshold. If it is low, the intake efficiency is corrected to increase the in -cylinder air amount, and the intake efficiency correction amount is learned based on the intake pipe pressure measurement value and the intake pipe pressure estimation value. do
Internal combustion engine controller. The internal combustion engine control device according to claim 1 , wherein the air amount estimator estimates the in-cylinder air amount based on at least a correction coefficient that differs depending on whether supercharging or non-supercharging. The internal combustion engine control device according to claim 1 , wherein the air amount estimating section estimates the in-cylinder air amount based on a correction coefficient that varies depending on the load level of the internal combustion engine. 4. The internal combustion engine control device according to claim 3 , wherein the load level of the internal combustion engine is an estimated pressure value of the intake pipe. 4. The air amount estimator according to claim 3 , wherein the air amount estimator acquires a correction value for estimating the in-cylinder air amount from a table having two variables, an estimated pressure value of the intake pipe and a wall surface temperature of the cylinder, as arguments. internal combustion engine controller. When the ratio of the estimated pressure value of the intake pipe to the measured pressure value of the intake pipe is equal to or greater than a predetermined threshold value, the air amount estimating unit uses the ratio as a learning value associated with the wall surface temperature of the cylinder. 2. The internal combustion engine control device according to claim 1 , wherein the learning value is stored and the intake efficiency is corrected based on the learned value.

Images