JP2002364416A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine having high robust property in relation to a fluctuation of the internal combustion engine speed and excellent operability when controlling a fuel preceding cylinder injection type internal combustion engine. SOLUTION: This control device for a fuel preceding internal combustion engine is provided with a target torque computing means for computing the target torque of the internal combustion engine, a target output computing means for computing a target output of the internal combustion engine, and a target fuel quantity computing means for computing the target fuel quantity on the basis of the target torque obtained by the target torque computing means and the target output obtained by the target output computing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for an internal combustion engine, and more particularly to a control apparatus for an internal combustion engine for improving drivability in fuel-first control.

[0002]

2. Description of the Related Art In recent years, in the technical field of automobiles, a fuel-efficient internal combustion engine has been demanded due to efforts for energy saving on a worldwide scale. As the internal combustion engine corresponding to the demand, a lean burn type internal combustion engine is the best, and among the lean burn type internal combustion engines, in particular, a direct injection internal combustion engine injects fuel directly into a cylinder. By stratifying the air-fuel mixture, it is possible to burn at an air-fuel ratio of 40 or more, and the pump loss is reduced.

In such a lean burn type direct injection internal combustion engine system, since the air flow rate and the torque are not in a proportional relationship, unlike the conventional internal combustion engine system, an electronic throttle for electronically controlling the air flow rate is provided. It is generally used. In addition, in the lean-burn type direct injection internal combustion engine system, torque demand control for realizing the driver's intended torque in a wide range of air-fuel ratio is required. There are two forms.

In the air leading type, as shown in FIG. 9, a target torque calculating unit and a target air-fuel ratio calculating unit determine a target torque and a target air-fuel ratio, and a target air amount calculating unit for realizing the target torque and the target air-fuel ratio. Calculate the amount, control the air amount with the electronic throttle,
The actual air amount is detected by an air amount sensor, and the fuel injection amount is determined by a fuel injection amount calculation unit from the actual air amount and the target air-fuel ratio.

On the other hand, in the fuel advance type, as shown in FIG. 10, a target torque is determined by a target torque calculator, and a fuel injection amount for realizing the target torque is determined by the fuel injection amount calculator. The target air amount is calculated from the fuel injection amount and the target air-fuel ratio by the target air amount calculation unit, and the air amount is controlled by the electronic throttle. Further, in the advanced fuel type, it is possible to perform F / B control of the air amount based on the output value of the air flow sensor.

As a prior art of a fuel-injection type direct injection type internal combustion engine, for example, in order to control the output of the internal combustion engine with high accuracy, the intake air amount (that is, the intake air amount of the internal combustion engine) When the output is determined, it is proposed that the throttle valve opening and closing device be driven in advance so that the intake air amount reaches the target intake air amount in order to accurately realize the actual intake air amount accordingly. JP 20
00-97086). Another prior art of a fuel-injection type direct injection type internal combustion engine includes a fuel injection and an air intake in order to suppress a change in an air-fuel ratio, a deterioration in drivability and exhaust due to a response delay of the air intake to the fuel injection. (Japanese Patent Laid-Open No. 11-15937).
No. 7).

[0007]

By the way, in the air leading type, the air is controlled by a throttle and the fuel injection amount is determined based on the detected actual air amount.
Since the internal combustion engine is an engine that performs intermittent combustion, in general, the fuel injection amount per operation is one time during the period when the internal combustion engine makes two revolutions in the case of a four-stroke internal combustion engine in order to keep the air-fuel ratio constant. The fuel is injected according to the actual amount of air flowing into the cylinder.

Accordingly, the fuel injection amount per one time is
The value is proportional to the torque. As described above, the air leading type has a configuration in which the target output is controlled by the actual air amount, and uses a method of converting the actual output to a target torque that achieves the target output at an arbitrary rotation speed. I can. For example, if the internal combustion engine speed fluctuates due to disturbance in a state where the air amount is constant (output is constant),
The fuel injection amount, that is, the torque, is automatically controlled so that the target output is realized. Further, when the air amount is intentionally changed by the throttle valve, the fuel injection amount, that is, the torque, is automatically controlled so that an output corresponding to the air amount is realized. As described above, it can be said that the air leading type has a function of performing output control that is robust against rotation fluctuation.

However, in the fuel-advanced type, it is general that the target torque is pre-scheduled in advance from the internal combustion engine speed and the accelerator opening. At this time, the internal combustion engine speed is deliberately set to its value. It is said. From this, in actual running, when the internal combustion engine speed changes,
Is it due to intentionally changing the air volume,
It cannot be distinguished whether it is due to unintended disturbance.

For example, the target torque to be obtained, that is, the fuel injection amount, is the same regardless of whether the rotation speed is increased due to an intentional increase in the air amount or the rotation speed is increased due to unintended disturbance. For this reason, the fuel-advanced type has a lower robustness with respect to the fluctuation of the internal combustion engine rotation speed than the air-advanced type, which causes deterioration in drivability. Further, there is a problem that a deterioration phenomenon of the drivability (stability) of the internal combustion engine with respect to the fluctuation of the internal combustion engine speed becomes remarkable at the time of idling control. This problem is not taken into account in the prior art.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce fluctuations in internal combustion engine rotation speed in the control of a fuel-injection type direct injection internal combustion engine. To provide a control device for an internal combustion engine having high robustness and good drivability.

[0012]

In order to achieve the above object, a control apparatus for an internal combustion engine according to the present invention is basically of a fuel-first type, and calculates a target torque for calculating a target torque of the internal combustion engine. Means, a target output calculating means for calculating a target output of the internal combustion engine, and a target fuel amount calculation for calculating a target fuel amount from the target torque obtained by the target torque calculating means and the target output obtained by the target output calculating means. Means (see FIG. 1).
According to the present invention, since the above-described configuration is a control device in which output (power) control is added to a control device for torque control of a fuel-advanced internal combustion engine, robustness against disturbances due to rotation fluctuations of the internal combustion engine is high. Drivability is improved.

The control device for an internal combustion engine according to the present invention is a fuel-leading type, and has a target torque means for calculating a target torque of the internal combustion engine, a target work per unit time of the internal combustion engine, that is, a target output. A target output calculating means for calculating; a fuel injection amount calculating means for calculating a fuel injection amount using either the target torque obtained by the target torque calculating means or the target output obtained by the target output calculating means; It is characterized by comprising switching means for switching the input value of the injection amount calculating means to either target torque or target output, and switching determination means for determining a switching condition (see FIG. 2).

According to the present invention, drivability can be improved by “switching” between torque control and output (power) control according to the operating conditions of the internal combustion engine.
Output control during idling increases control stability. Further, the control device for an internal combustion engine according to the present invention is a fuel advance type, wherein first target torque calculation means for calculating a first target torque of the internal combustion engine, and target output calculation means for calculating a target output of the internal combustion engine Conversion means for converting the target output obtained by the target output calculation means into a target torque;
A second target torque calculating means for calculating a second target torque based on the first target torque and a target torque obtained by converting the target output, and a second target torque calculated by the second target torque calculating means. And a target fuel amount calculating means for calculating a target fuel amount from the two target torques (see FIG. 3).

According to the present invention, the control amount (fuel amount) of the internal combustion engine can be integrally controlled by torque control by converting the target output into the target torque by the above configuration, and the fuel injection amount is proportional to the torque. Control becomes easy.
Still further, the control device for the internal combustion engine of the present invention is a fuel advance type, wherein a target torque calculating means for calculating a target torque of the internal combustion engine, and a first target output calculation for calculating a first target output of the internal combustion engine. Means, and conversion means for converting the target torque determined by the target torque calculation means into a target output,
Second target output calculating means for calculating a second target output based on the first target output and a target output obtained by converting the target torque, and a second target output calculating means calculated by the second target output calculating means. And a target fuel amount calculating means for calculating a target fuel amount from the two target outputs (FIG. 4).

According to the present invention, the control amount (air amount) of the internal combustion engine can be integrally controlled by the output control by converting the target torque into the target output by the above configuration, and the air flow rate is proportional to the output. Because there is, control is easy. In a more specific aspect of the control device for an internal combustion engine according to the present invention, the control device for the internal combustion engine further includes a target air-fuel ratio calculating unit configured to calculate a target air-fuel ratio of the internal combustion engine; And a target air amount calculating means for calculating a target air amount based on the target air-fuel ratio (FIG. 5). Can be coordinated.

Further, another specific aspect of the control apparatus for an internal combustion engine of the present invention is characterized in that the target torque calculating means calculates a target torque based on an accelerator opening and an internal combustion engine speed. (See FIG. 6), target internal combustion engine speed calculating means for calculating a target internal combustion engine speed, and target output calculating means for calculating a target output from the target internal engine speed and the internal combustion engine speed. (See FIG. 7), the target output calculating means calculates first target output based on the target internal combustion engine speed, the first target output calculating means, the target internal combustion engine speed, and the internal combustion engine speed. And a second target output calculating means for calculating a second target output based on the engine speed (see FIG. 8).

According to the present invention, the same function as that of the air leading type can be obtained by determining the target torque from the accelerator and the rotation speed by the above configuration, and the output control is performed based on the target rotation speed and the actual rotation speed. A target output is calculated, and output control is performed during idling (rotation speed control), and F / F control and F / B control are performed for output control (idle control), and a response is obtained by F / F control. , And robustness can be ensured by the F / B control.

Still further, in a further specific aspect of the control apparatus for an internal combustion engine according to the present invention, the target output calculated by the target output calculating means is determined by determining a target air amount flowing into the internal combustion engine during a predetermined period. Or a target rotation speed of the internal combustion engine, wherein the target torque calculated by the target torque calculation means is a fuel injection amount per cylinder during two rotations of the four-cycle internal combustion engine. It is characterized by:

According to the present invention, as described above, by setting the parameter of the target output to the inflow air amount or the internal combustion engine speed, the control design is easy, there is no need to measure the output in the control, and the parameter of the target torque is not required. Is set as the fuel injection amount per cylinder during two rotations of the four-cycle internal combustion engine, control design is easy, and it is not necessary to measure torque in control.

As described above, according to the present invention, in the fuel-advanced control, the fuel injection amount is controlled so as to achieve the target output, so that the torque control that is robust against unintended disturbances becomes possible. In both the off-idle state and the off-idle state, a suitable operation state can be realized.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a control device for an internal combustion engine of the present invention will be described in detail with reference to the drawings. FIG.
1 shows the overall system configuration of an internal combustion engine to which the control device for an internal combustion engine of the present embodiment is applied.

The internal combustion engine 20 is constituted by a multi-cylinder direct injection internal combustion engine. In the intake system, air from the outside passes through the air cleaner 1 and flows into the cylinder via the intake manifold 4 and the collector 5. The inflow air amount is adjusted by the electronic throttle 3. A spark plug 8 and a fuel injection valve 7 are attached to a cylinder 9 of each cylinder.
And an exhaust valve 28 are arranged.

In the exhaust system, an exhaust manifold 10 is connected to a cylinder 9 of each cylinder, and a three-way catalyst 11 is disposed in the exhaust manifold 10. A three-way catalyst 11 is provided between the cylinder 9 and the three-way catalyst 11. The / F sensor 12 is attached.
An exhaust circulation passage (EGR passage) 18 that connects the intake manifold 4 and the exhaust manifold 10 by bypassing the cylinder 9 of each cylinder is provided, and an EGR valve 19 is disposed in the exhaust circulation passage 18.

An air flow sensor 2 is disposed in the intake manifold 4 of the intake system. The air flow sensor 2 detects the amount of inflow air, and a crank angle sensor 15 outputs a signal every one degree of the crankshaft rotation angle. The throttle opening sensor 17 attached to the electronic throttle 3 detects the opening of the electronic throttle 3, and the water temperature sensor 14 detects the cooling water temperature of the internal combustion engine 20. Accelerator opening sensor 13
Detects the amount of depression of the accelerator 6, and thereby detects the required torque of the driver.

The signals of the accelerator opening sensor 13, the air flow sensor 2, the throttle opening sensor 17, the crank angle sensor 15, and the water temperature sensor 14 are sent to the control unit 50. Of the operating state, the intake air amount, the fuel injection amount,
The main operation amounts of the internal combustion engine 20, such as the ignition timing, are optimally calculated. The fuel injection amount calculated in the control unit 50 is converted into a valve opening pulse signal and sent to the fuel injection valve 7.

The control unit 50 calculates a predetermined ignition timing, and outputs a drive signal to the ignition plug 8 so that ignition is performed at the ignition timing. The intake air from the intake system is adjusted by the electronic throttle 3, mixed with the exhaust recirculation gas adjusted by the EGR valve 19, and flows into the cylinder 9 via the intake valve 27.

The fuel injected from the fuel injection valve 7 into the cylinder (combustion chamber) 9 is mixed with the air flowing from the intake manifold 4 to form an air-fuel mixture. The air-fuel mixture explodes due to a spark generated from the spark plug 8 at a predetermined ignition timing, and pushes down the piston 29 due to the combustion pressure thereof, and becomes power for the internal combustion engine 20. Exhaust gas after the explosion is sent to the three-way catalyst 11 through the exhaust manifold 10 and the HC, CO, NO
Each exhaust component of x is purified in the three-way catalyst 11 and discharged again to the outside.

The amount of exhaust gas recirculated to the intake side through the exhaust gas recirculation pipe 18 is controlled by an EGR valve 19. The A / F sensor 12 includes the internal combustion engine 20 and the three-way catalyst 1
1 and has a linear output characteristic with respect to the oxygen concentration contained in the exhaust gas. Since the relationship between the oxygen concentration in the exhaust gas and the air-fuel ratio is almost linear, By the A / F sensor 12 for detecting the oxygen concentration,
The air-fuel ratio of the internal combustion engine 20 can be obtained.

The control unit 50 calculates the air-fuel ratio upstream of the three-way catalyst 11 from the signal of the A / F sensor 12, and calculates the air-fuel ratio of the air-fuel mixture in the cylinder 9 of the internal combustion engine 20.
It is configured to perform feedback control for sequentially correcting the fuel injection amount or the air amount so as to reach the target air-fuel ratio.

FIG. 12 shows the internal configuration of the control unit (ECU) 50 of the internal combustion engine 20 of FIG. Sensor output values of the A / F sensor 12, the temperature sensor 14, the throttle valve opening sensor 17, the air flow sensor 2, and the internal combustion engine speed sensor 15 are input into the ECU 50. After performing signal processing such as removal, the signal is sent to the input / output port 55. The value of the input / output port 55 is stored in the RAM 53 and is processed in the CPU 51. A control program describing the contents of the arithmetic processing is written in the ROM 52 in advance.

The values representing the actuator operation amounts calculated according to the control program are stored in the RAM 53 and then sent to the input / output port 55. The ON / OFF signal of the ignition plug 8 used during spark ignition combustion is set to ON when the primary coil in the ignition output circuit 56 is conducting and OFF when not conducting. Ignition timing
It is time to turn from ON to OFF. The signal for the ignition plug set in the input / output port 55 is amplified by the ignition output circuit 56 to an energy sufficient for combustion, and supplied to the ignition plug 8.

The drive signal of the fuel injection valve 7 is output when the valve is opened.
An ON / OFF signal which is turned ON and OFF when the valve is closed is set, and is amplified by a fuel injection valve drive circuit 57 to energy sufficient to open the fuel injection valve 7 and sent to the fuel injection valve 7. The drive signal for realizing the target opening of the electronic throttle 3 is sent to the electronic throttle 3 via the electronic throttle drive circuit 58. Hereinafter, a control program written in the ROM 52 of the EPU 50 will be described.

FIG. 13 shows the EPU5 of this embodiment shown in FIG.
FIG. 2 is a control block diagram of the entire control of 0, and shows a main part of a fuel advance type torque demand control. The control of the present embodiment includes a target torque calculator 61, a target output calculator 69, a fuel injection amount calculator 62, a fuel injection amount corrector 63, a target equivalent ratio calculator 64, a target air amount calculator 65, and an actual air amount. It comprises a calculation unit 66, a target throttle opening calculation unit 67, and a throttle opening control unit 68.

The target torque calculator 61 calculates the accelerator opening
Accelerator required torque TgTs from Apo and internal combustion engine speed Ne
And the target output calculator 69 calculates the accelerator opening Apo
From the internal combustion engine rotation speed Ne, calculate an idle rotation speed maintenance equivalent air flow rate TgTl in a proportional relationship with the output of the internal combustion engine, and calculate the target torque TgTc from the accelerator request minute torque TgTs and the idle rotation speed maintenance equivalent air flow rate TgTl. Calculate. The fuel injection amount calculator 62 calculates a fuel injection amount TIO for realizing the target torque TgTc. In the fuel injection amount correction unit 63,
The phase correction is performed so that the fuel injection amount TI0 matches the phase of the air in the cylinder 9, and the corrected fuel injection amount TI is calculated.

In the target equivalence ratio calculation section 64, the target torque Tg
A target equivalent ratio TgFbya is calculated from Tc and the internal combustion engine speed Ne. The reason why the ratio of fuel and air is handled by the equivalence ratio is that it is convenient for calculation, and it is possible to handle the ratio by air-fuel ratio. The target equivalence ratio calculation unit 64 also determines whether to perform homogeneous combustion or stratified combustion. The target air amount calculating section 65 calculates a target air amount TgTp from the fuel injection amount TI0 and the target equivalent ratio TgFbya. As described later, the target air amount TgTp
Is a value normalized for convenience to the amount of air flowing into one cylinder per cycle. Actual air amount calculation unit 6
In 6, the mass flow rate of air detected by the airflow sensor 2
Qa is converted into an actual air amount Tp flowing into one cylinder per cycle, which is the same dimension as the target air amount TgTp, and is output.

The target throttle opening calculating section 67 calculates the target throttle opening based on the target air amount TgTp and the actual air amount Tp.
Calculate TgTvo. The throttle opening calculator 68 calculates a throttle operation amount Tduty from the target throttle opening TgTvo and the actual opening Tvo. The throttle operation amount Tduty is input to the drive circuit that controls the current for driving the throttle motor.
It shows the duty ratio of the PWM signal. Next, the respective control operation units and correction units of the control block of the present embodiment are shown in FIG.
This will be described in detail with reference to FIGS.

1. Target Torque Calculation Unit and Target Output Calculation Unit FIG. 14 shows the target torque calculation unit 61 and the target output calculation unit 69. The target torque calculation unit 61 calculates the relationship between the accelerator opening Apo and the internal combustion engine speed Ne. The accelerator request torque TgTs is calculated from the table 61a, and the target output calculation unit 6
Reference numeral 9 denotes an operation for calculating an air flow rate TgTl corresponding to the idling rotation speed maintenance amount proportional to the output. The accelerator request amount of the target torque calculation unit 61 is torque control, and the idle control amount of the target output calculation unit 69 is output control. . The calculated accelerator required torque TgTs is used to maintain the idling speed maintenance equivalent air flow Tg.
The target combustion pressure equivalent torque TgTc is calculated by interpolation with Tl.

The control amount TgTf0 of the idle F / F control 69a of the target output calculation unit 69 is determined from the target rotation speed TgNe of the target rotation speed calculation unit 70 of the target internal combustion engine with reference to the table TblTgTf. The idle F / B control 69 c
In order to correct the error of the control of the / F control 69a, it functions only at the time of idling. The determination of whether or not the engine is idling is made by the judging means 69b when the accelerator opening Apo is smaller than the predetermined value ApIdle. Although the algorithm of the F / B control is not specifically shown here, for example, PID control or the like can be considered. It is desirable that the set value of the table TblTgTf be determined from the data of the actual device.

The manipulated variable TgTl of the idle control of the target output computing section 69 (the air flow rate corresponding to the idling rotation speed maintenance) is an air flow rate at the time of stoichiometry in a proportional relationship with the output, and performs a dimension conversion from the output to the torque. Means 69d, and the gain K / Ne is provided by the dimension conversion means 69d. It is assumed that K of the gain K / Ne is determined by the flow characteristics of the injector (fuel injection valve).

2. Fuel Injection Amount Calculation Unit FIG. 15 shows a fuel injection amount calculation unit 62,
Here, the target combustion pressure torque TgTc is converted and controlled into the fuel injection amount TIO. Here, the fuel injection amount TI0 is a fuel injection amount per one cylinder and one cycle, so the fuel injection amount TI0 is proportional to the torque. Using this proportional relationship,
The target combustion pressure torque TgTc is converted into a fuel injection amount TI0. The gain may be used, but the table may be converted in consideration of some errors. It is desirable that the set value be determined from actual machine data.

3. Fuel Injection Amount Correcting Unit FIG. 16 shows the fuel injection amount correcting unit 63.
Here, correction is performed to match the fuel injection amount TI0 to the phase of the air in the cylinder 9. Throttle 3
Of the air from the cylinder to the cylinder 9 is approximated by a dead time + first-order lag system. Parameter n representing dead time
1. It is desirable that the set value of the time constant equivalent parameter Kair of the first-order lag system be determined from actual machine data. Further, the parameter n1 and the parameter Kair may be changed according to various operating conditions.

4. Target Equivalence Ratio Calculator FIG. 17 shows a target equivalence ratio calculator 64,
Here, the determination of the combustion state and the calculation of the target equivalent ratio are performed.
Fpstratify is a stratified combustion permission flag, and Fpstratify = 1
At this time, the injection timing, ignition timing, injection amount, and air amount are controlled to perform stratified combustion. Note that the determination of the injection timing and the ignition timing is not specifically described here. Fpstratify
Is 1, if the values of the water temperature Twn, the accelerator opening Apo, and the number of revolutions Ne satisfy the conditions, the stratified combustion is permitted.

When stratified charge combustion is permitted, the target equivalence ratio map Mtgfba # s for stratified charge combustion is set to a value referred to from the target combustion pressure torque TgTc and the rotation speed Ne as the target equivalence ratio TgFbya. When TgFbya = 0, homogeneous combustion is assumed, and the target equivalent ratio map for homogeneous combustion Mtgf
ba is a value referred to from the target combustion pressure torque TgTc and the rotation speed Ne as a target equivalence ratio TgFbya. It is desirable that the set values of the stratified combustion target equivalent ratio map Mtgfba # s and the homogeneous combustion target equivalent ratio map Mtgfba be determined from actual machine data.

5. Target air amount calculating unit FIG. 18 shows a target air amount calculating unit 65,
Here, the target air amount TgTp is calculated. For convenience, the target air amount TgTp is calculated as a value standardized to the amount of air flowing into one cylinder per cycle. As shown in FIG. 18, the target air amount TgTp is calculated from the fuel injection amount TIO and the target equivalence ratio TgFbya as TgTp = TI0 × (1 / TgFbya).

6. Actual Air Amount Calculating Unit FIG. 19 shows the actual air amount calculating unit 66, which calculates the actual air amount Tp. For convenience, the actual air volume Tp
Is calculated as a normalized value of the amount of air flowing into one cylinder per cycle, as shown in FIG. Here, Qa is the air flow rate detected by the airflow sensor 2. K is determined so that the actual air amount Tp becomes the fuel injection amount at the stoichiometric air-fuel ratio. Cyl is the number of cylinders of the internal combustion engine.

7. Target Throttle Opening Calculation Unit The one shown in FIG.
Here, the target throttle opening TgTVO is calculated from the target air amount TgTp and the actual air amount Tp. The target throttle opening calculating section 67 obtains the target throttle opening TgTVO from the target air amount TgTP and the actual air amount Tp, and sets the F / B control to PID control. Each gain is the target air amount Tg
Although the difference is given by the magnitude of the deviation between Tp and the actual air amount Tp, it is desirable to determine a specific set value from actual machine data. LPF for removing high frequency noise
(LowPassFilter) is provided.

8. Throttle opening control unit FIG. 21 shows the throttle opening control unit 68, which calculates the throttle drive operation amount Tduty from the target throttle opening TgTVO and the actual throttle opening Tvo. Also, as described above, the throttle drive operation amount Td
uty indicates the duty ratio of the PWM signal input to the drive circuit that controls the current for driving the throttle motor.
Here, the throttle drive operation amount Tduty is obtained by PID control. Although details are not specifically described, it is desirable to tune each gain of the PID control to an optimum value using an actual machine. As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and various designs may be made without departing from the spirit of the present invention described in the claims. Can be changed.

For example, as another embodiment of the present invention,
As shown in FIG. 2, the control device 50 for the fuel-advanced internal combustion engine includes a target torque unit 61, a target output calculation unit 69, and a target torque calculated by the target torque calculation unit 61 or the target output. A fuel injection amount calculating means 62 for calculating a fuel injection amount using any of the target outputs obtained by the calculating means 69, and an input value of the fuel injection amount calculating means 62 is switched to either a target torque or a target output. A configuration including switching means 71 and switching determination means 70 for determining a switching condition may be employed.
With this configuration, drivability can be improved by "switching" between torque control and output (power) control depending on the operating conditions of the internal combustion engine, and the stability of control can be improved by using output control during idling. Can be increased.

As still another embodiment of the present invention, as shown in FIG. 4, a control device 50 for a fuel-advanced internal combustion engine is provided with a target torque calculating means for calculating a target torque of the internal combustion engine. 61; first target output calculation means 69 for calculating a first target output of the internal combustion engine; conversion means 61c for converting the target torque obtained by the target torque calculation means 61 into a target output; A second target output calculating means 69e for calculating a second target output based on the output and a target output obtained by converting the target torque, and a second target output calculated by the second target output calculating means 69e. Target fuel amount calculating means 62 for calculating the target fuel amount from the output
And a configuration including: By converting the target torque into the target output by the above configuration, the control amount (air amount) of the internal combustion engine can be integrally controlled by the output control, and the air flow rate is proportional to the output, which facilitates the control. .

[0051]

As will be understood from the above description, the control apparatus for an internal combustion engine of the present invention controls the fuel injection amount so as to achieve the target output in the control of the fuel-advanced internal combustion engine. This makes it possible to perform robust torque control with respect to disturbances that do not occur, and to achieve a favorable operation state during both idling and off-idling.

[Brief description of the drawings]

FIG. 1 is a diagram showing a control device for an internal combustion engine according to claim 1.

FIG. 2 is a diagram showing a control device for an internal combustion engine according to claim 2;

FIG. 3 is a diagram showing a control device for an internal combustion engine according to claim 3;

FIG. 4 is a diagram showing a control device for an internal combustion engine according to claim 4.

FIG. 5 is a diagram showing a control device for an internal combustion engine according to claim 5;

FIG. 6 is a diagram showing a control device for an internal combustion engine according to claim 6;

FIG. 7 is a diagram showing a control device for an internal combustion engine according to claim 7;

FIG. 8 is a diagram showing a control device for an internal combustion engine according to claim 8.

FIG. 9 is a torque demand control block diagram of an air-preceding internal combustion engine.

FIG. 10 is a torque demand control block diagram of a fuel-advanced internal combustion engine.

FIG. 11 is an overall configuration diagram of an internal combustion engine system including an internal combustion engine control device according to an embodiment of the present invention.

12 is an internal configuration diagram of a control portion (control unit) of the control device for an internal combustion engine in FIG. 11;

FIG. 13 is an overall control block diagram of the control device for the internal combustion engine of the embodiment of FIG. 11;

14 is a control block diagram of a target torque calculator and a target output calculator in the control block diagram of FIG.

FIG. 15 is a control block diagram of a fuel injection amount calculation unit in the control block diagram of FIG. 13;

FIG. 16 is a control block diagram of a fuel injection amount correction unit in the control block diagram of FIG. 13;

FIG. 17 is a control block diagram of a target equivalent ratio calculation unit in the control block diagram of FIG. 13;

FIG. 18 is a control block diagram of a target air amount calculation unit in the control block diagram of FIG. 13;

FIG. 19 is a control block diagram of an actual air amount calculation unit in the control block diagram of FIG. 13;

20 is a control block diagram of a target throttle opening calculator in the control block diagram of FIG. 13;

FIG. 21 is a control block diagram of a throttle opening control section in the control block diagram of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air cleaner 2 Air flow sensor 3 Electronic throttle 4 Intake pipe 5 Collector 6 Accelerator 7 In-cylinder fuel injection valve 8 Spark plug 9 Internal combustion engine 10 Exhaust pipe 11 Three-way catalyst 12 A / F sensor 13 Accelerator opening sensor 14 Water temperature sensor 15 Internal combustion engine speed sensor 16 Control unit 17 Throttle opening sensor 18 Exhaust gas recirculation pipe 19 Exhaust gas recirculation amount control valve 20 Internal combustion engine 27 Intake valve 28 Exhaust valve 29 Piston 50 Control device (control unit) 61 Target torque calculation unit (Target torque calculation) Means) 62 fuel injection amount calculation unit (target fuel amount calculation unit) 63 fuel injection amount correction unit 64 target equivalent ratio calculation unit (target air-fuel ratio calculation unit) 65 target air amount calculation unit (target air amount calculation unit) 66 actual air Amount calculation unit 67 Target throttle opening calculation unit 68 slot Opening control unit 69 target output calculating section (target output calculating means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masami Nagano 2520 Ojitakaba, Hitachinaka City, Ibaraki Prefecture Inside the Hitachi, Ltd. Automotive Equipment Group (72) Inventor Toshio Dori 2520 Odaikaba, Hitachinaka City, Ibaraki Prefecture 3G084 BA13 DA11 EB09 EB13 FA07 FA10 FA20 FA26 FA29 FA31 FA32 FA33 3G301 HA01 JA04 KA06 KA23 MA11 NC04 ND05 PA01Z PA11Z PD02Z PE01Z PE06Z PE08Z PF03Z

Claims (11)

[Claims] 1. A control device for a fuel-advanced internal combustion engine, comprising: target torque calculating means for calculating a target torque of the internal combustion engine; target output calculating means for calculating a target output of the internal combustion engine; A control device for an internal combustion engine, comprising: target fuel amount calculating means for calculating a target fuel amount from the determined target torque and the target output determined by the target output calculating means. 2. A control device for a fuel-advanced internal combustion engine, comprising: target torque means for calculating a target torque of the internal combustion engine; and target output calculation means for calculating a target work per unit time of the internal combustion engine, ie, a target output. And a fuel injection amount calculating means for calculating a fuel injection amount using either the target torque obtained by the target torque calculating means or the target output obtained by the target output calculating means, and an input to the fuel injection amount calculating means. A control device for an internal combustion engine, comprising: switching means for switching a value to either a target torque or a target output; and switching determination means for determining a switching condition. 3. A control device for a fuel-advanced internal combustion engine, comprising: first target torque calculating means for calculating a first target torque of the internal combustion engine; target output calculating means for calculating a target output of the internal combustion engine; A conversion unit that converts the target output obtained by the output calculation unit into a target torque; and a second unit that calculates a second target torque based on the first target torque and a target torque obtained by converting the target output. A control device for an internal combustion engine, comprising: two target torque calculation means; and target fuel amount calculation means for calculating a target fuel amount from the second target torque obtained by the second target torque calculation means. 4. A control device for a fuel-advanced internal combustion engine, comprising: target torque calculating means for calculating a target torque of the internal combustion engine; first target output calculating means for calculating a first target output of the internal combustion engine; A converting means for converting the target torque obtained by the torque calculating means into a target output; and a second calculating means for calculating a second target output based on the first target output and a target output obtained by converting the target torque. A control device for an internal combustion engine, comprising: two target output calculating means; and target fuel amount calculating means for calculating a target fuel amount from a second target output obtained by the second target output calculating means. 5. A target air-fuel ratio calculating means for calculating a target air-fuel ratio of an internal combustion engine, a target air amount calculating means for calculating a target air amount based on the target fuel amount and the target air-fuel ratio,
The control device for an internal combustion engine according to any one of claims 1 to 4, further comprising: 6. The control of an internal combustion engine according to claim 1, wherein said target torque calculation means calculates a target torque based on an accelerator opening and an internal combustion engine speed. apparatus. 7. A control device for a fuel-advanced internal combustion engine, comprising: a target internal combustion engine speed calculating means for calculating a target internal combustion engine speed; and a target output for calculating a target output from the target internal engine speed and the internal combustion engine speed. The control device for an internal combustion engine according to any one of claims 1 to 6, further comprising target output calculation means. 8. The target output calculating means for calculating a first target output based on the target internal combustion engine speed, based on the target internal engine speed and the internal engine speed. And a second target output calculating means for calculating a second target output by using the second target output calculating means.
3. The control device for an internal combustion engine according to claim 1. 9. The internal combustion engine according to claim 1, wherein the target output calculated by the target output calculation means is a target air amount flowing into the internal combustion engine for a predetermined period. Engine control device. 10. The control device for an internal combustion engine according to claim 1, wherein the target output calculated by the target output calculation means is a target rotation speed of the internal combustion engine. 11. The target torque calculated by the target torque calculating means is a fuel injection amount per cylinder during two rotations of a four-cycle internal combustion engine. A control device for an internal combustion engine according to claim 1.