JPH10159623A - Vehicular engine controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular engine controller which can certainly attempt compatibility between a fail-safe function that an engine torque may not be needlessly increased even through abnormality occurs in the drive control system of a throttle valve, and automatic cruise control and VSC control by which the opening of the throttle valve is adjusted according to the condition of a vehicle except for an accelerator manipulated variable. SOLUTION: In a vehicular engine controller which sets the target opening of a throttle valve according to an accelerator opening (the manipulated variable of an accelerator pedal) or the condition of a vehicle except for the accelerator opening (S110), and adjusts the opening of the throttle valve to the set target opening, and also calculates a fuel injection quantity according to the operating condition of an engine (S130, S140), and supplies fuel to the engine, the maximum injection quantity being the upper limit of the fuel injection quantity is set according to the target opening of the throttle valve (S120), and the fuel injection quantity supplied to the engine is limited within the set maximum injection quantity (S150, S160).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine control system for electrically controlling the opening of a throttle valve.

[0002]

2. Description of the Related Art Conventionally, as a vehicle engine controller, a throttle valve is not directly opened and closed by a link mechanism linked to an accelerator pedal, but is electrically detected by an operation amount of an accelerator pedal (accelerator operation amount). An engine control device employing a so-called linkless throttle system has been put to practical use in which the opening degree of a throttle valve is controlled by an electric actuator such as a motor in accordance with the detected accelerator operation amount.

[0003] In this type of engine control device,
The actuator itself and a drive circuit for operating the actuator, etc., are constantly monitored to determine whether or not the drive control system of the throttle valve is normal, and when it is determined that an abnormality has occurred, the power supply to the actuator is forcibly stopped. Or so-called fuel cut or the like for stopping the supply of fuel to the engine.

That is, in normal engine control, the amount of air flowing into the engine (intake air amount) is detected by opening the throttle valve, and the fuel supply amount to the engine is determined according to the detected intake air amount. Therefore, if an abnormality occurs in the drive control system of the throttle valve and the throttle valve is greatly opened against the driver's intention, the fuel supply amount is increased accordingly, and as a result, the driver This is because the engine torque may increase more than expected.

[0005] However, even if the above-described fail-safe operation is performed, if the abnormality detection circuit for detecting an abnormality or the like fails at the same time, there is no longer any help. Therefore, as a technique for solving the problem of such a rare case, for example, JP-A-63-1
No. 47940 discloses that an upper limit value of a fuel supply amount is set according to an accelerator operation amount, and a fuel supply amount determined according to a driving state of a vehicle exceeds the above set upper limit value. It has been proposed to perform control such as limiting the supply amount to its upper limit.

According to this technique, even in the worst case where the drive control system of the throttle valve and the abnormality detection circuit for detecting the abnormality of the throttle valve simultaneously break down,
Unnecessary increase in engine torque can be prevented.

[0007]

However, in the technology disclosed in the above publication, the upper limit of the fuel supply amount is set based on the operation amount of the accelerator pedal operated by the driver. There's a problem.

For example, when so-called auto cruise control for running the vehicle at a constant speed set by the driver is performed, the driver releases his / her foot from the accelerator pedal, and the accelerator operation amount becomes zero. Then, in the above prior art, the upper limit value of the fuel supply amount is set extremely low, and it is not possible to obtain sufficient engine torque when traveling uphill, and in the worst case, the engine may be stalled. is there.

In recent years, a so-called VSC that suppresses understeer and oversteer of a vehicle to improve running stability has been developed.
(Vehicle Stability Control) control is employed, but in this VSC control, during braking operation by the driver (usually, accelerator operation amount = 0 at this time), the throttle valve is opened to some extent to increase engine torque. May be performed. However, also in this case, in the related art in which the upper limit value of the fuel supply amount is set based on the accelerator operation amount, the upper limit value of the fuel supply amount is set extremely low, and as a result, the engine torque can be increased. Therefore, the running stability of the vehicle cannot be improved.

As described above, in the technology disclosed in the above publication,
Regardless of the accelerator operation amount (even if the accelerator pedal is not depressed), various vehicle controls that may adjust the throttle valve to the open side, and even if an abnormality occurs in the drive control system of the throttle valve, the engine torque is reduced. The fail-safe function of not increasing unnecessarily cannot be achieved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a fail-safe function in which engine torque is not unnecessarily increased even if an abnormality occurs in a drive control system of a throttle valve. It is an object of the present invention to provide a vehicle engine control device that can reliably achieve control that adjusts according to a vehicle state other than the accelerator operation amount.

[0012]

Means for Solving the Problems and Effects of the Invention In the vehicle engine control apparatus of the present invention which has been made to achieve the above object, the target opening degree setting means normally comprises:
The target opening of the throttle valve is set according to the operation amount of the accelerator pedal operated by the driver, and when the driving state of the vehicle is in a predetermined specific state, the operation amount other than the operation amount of the accelerator pedal is set. The target opening of the throttle valve is set according to the vehicle state. Then, the drive signal output means outputs a drive signal corresponding to the target opening set by the target opening setting means to an actuator for driving the throttle valve, whereby the opening of the throttle valve is changed to the target opening. It is controlled to the target opening set by the setting means.

On the other hand, the fuel supply amount calculating means calculates the fuel supply amount to the engine based on the operating state of the engine including the intake air amount adjusted by the throttle valve. The upper limit of the amount of fuel supplied to the throttle valve is set to a larger value according to the target opening of the throttle valve set by the target opening setting means as the target opening is set to the opening side.

The limiting means compares the fuel supply amount calculated by the fuel supply amount calculating means with the upper limit set by the upper limit setting means, and the calculated fuel supply amount determines the upper limit. If it exceeds, the fuel supply amount to the engine is limited to the upper limit value, and the fuel supply unit supplies the engine with the fuel supply amount obtained via the limiting unit.

According to the vehicle engine control apparatus of the present invention, the drive control system for the throttle valve, which includes the actuator for driving the throttle valve and the drive signal output means for outputting a drive signal to the actuator, becomes abnormal. Even if the throttle valve opens more than necessary and the intake air amount of the engine increases, the amount of fuel supplied to the engine is limited to the upper limit according to the target opening of the throttle valve, so engine torque is not required Can be prevented from increasing.

Further, in the vehicle engine control device of the present invention, the target opening of the throttle valve is normally set according to the operation amount of the accelerator pedal, and the driving state of the vehicle is set to a predetermined specific state. In this case, it is set according to the vehicle state other than the operation amount of the accelerator pedal.In particular, the upper limit value for limiting the fuel supply amount is set according to the target opening degree of the throttle valve. Is set to a larger value as is set to the open side.

Therefore, for example, the above-described auto cruise control and VSC control are performed, and the target opening of the throttle valve is opened even though the operation amount of the accelerator pedal is 0 (that is, the accelerator pedal is fully closed). Side, the upper limit value of the fuel supply amount according to the target opening is set, and the appropriate engine torque can be obtained without insufficiency of the engine torque as in the related art described above. Obtainable.

Therefore, according to the vehicle engine control device of the present invention, a fail-safe function that the engine torque does not increase unnecessarily even if an abnormality occurs in the drive control system of the throttle valve, and the opening degree of the throttle valve is reduced. Control that adjusts according to the vehicle state other than the operation amount of the accelerator pedal can be compatible at a high level.

Since the intake air amount of the engine changes with a delay with respect to the change of the target opening of the throttle valve,
For example, when the target opening of the throttle valve changes from fully open to fully closed during VSC control or the like, if the upper limit of the fuel supply amount is suddenly set to the value when the target opening is fully closed. However, there is a possibility that the fuel supply amount becomes insufficient with respect to the actual intake air amount, and a misfire occurs in the engine.

In view of the above, an upper limit value change adjusting means is provided, and the upper limit value change adjusting means sets the target opening of the throttle valve set at least by the target opening setting means to the closing side. If the target opening degree of the throttle valve suddenly changes to the closing side as described above, if the upper limit value set by the upper limit value setting means and used by the limiting means is changed gradually, Thus, misfire of the engine can be reliably prevented, and a greater effect can be obtained.

Incidentally, the upper limit value change adjusting means may always change the upper limit value of the fuel supply amount gradually.
Only when the target opening of the throttle valve changes to the closing side, the upper limit of the fuel supply amount is gradually changed (ie,
The upper limit may be gently reduced).

Further, in order to prevent the engine from misfiring when the target opening of the throttle valve suddenly changes to the closing side, the throttle valve set by the target opening setting means is provided. A restriction operation prohibition unit that prohibits the restriction of the fuel supply amount by the restriction unit when the target opening degree of the target changes to the closing side may be provided.

In the configuration provided with such a limiting operation prohibiting means, when the target opening degree changes to the closing side, an abnormality occurs in the drive control system of the throttle valve, and the throttle valve opens more than necessary. When the intake air amount of the engine increases, the fuel supply amount also increases and the engine torque increases.However, when the change of the target opening to the closing side ends, the fuel supply amount is immediately limited. Prevention of important matters is prevented.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiment of the present invention
It goes without saying that the present invention is not limited to the following ones, but can take various forms as long as it belongs to the technical scope of the present invention.

First Embodiment First, FIG. 1 is a configuration diagram showing a vehicle engine control device according to a first embodiment together with the entire system of an engine 2. Note that the engine 2 of the present embodiment is a so-called four-cylinder engine having four cylinders, and a vehicle on which the engine 2 is mounted is a so-called rear-wheel drive vehicle having rear wheels as driving wheels.

As shown in FIG. 1, the engine 2 is provided with an intake passage 4 and an exhaust passage 6, and the intake passage 4
A throttle valve 8 for adjusting the amount of air (intake air) taken into the engine 2 is provided.
An air flow meter 10 for detecting an intake air amount is provided.

A motor 12 having a rotor connected to a rotating shaft of a throttle valve 8 via a gear is provided on an outer wall of the intake passage 4, and the throttle valve 8 is opened and closed by the motor 12. You. A return spring 14 for urging the throttle valve 8 in the fully closing direction, a throttle opening sensor 16 for detecting the actual opening of the throttle valve 8 (throttle opening) are provided on the rotation axis of the throttle valve 8. Is provided.

Further, an electromagnetic fuel injection valve 18 for injecting fuel for each cylinder is provided near the engine 2 in the intake passage 4, and the fuel injection valve 18 and the motor 12 It is driven by a control electronic control unit (hereinafter referred to as an engine ECU) 20.

The engine ECU 20 includes a CPU 20a, R
A well-known microcomputer including the OM 20b, the RAM 20c, and the like is configured as a main part, and also includes a drive circuit that outputs a drive signal to each of the motor 12 and the fuel injection valve 18 in accordance with a command from the microcomputer.

The engine ECU 20 includes an accelerator opening for detecting the accelerator opening, which is an operation amount of an accelerator pedal 22 operated by the driver of the vehicle, including the air flow meter 10 and the throttle opening sensor 16. A sensor 24, a rotation speed sensor 26 for detecting a rotation speed of the engine 2 (engine rotation speed), a water temperature sensor 28 for detecting a cooling water temperature of the engine 2, an air-fuel ratio sensor 30 for detecting a concentration of oxygen remaining in exhaust gas, and the like. , Engine 2
Sensor signals from various sensors for detecting the operating state of the vehicle are input. The engine ECU 20 has a vehicle speed setting switch 32 for so-called auto cruise control that allows the vehicle to run at a constant speed set by the driver.
Is also input.

Further, the engine ECU 20 includes a VSC control electronic control unit (hereinafter, referred to as VSC ECU) 34 for performing so-called VSC control, which suppresses understeer and oversteer of the vehicle and improves running stability. A transmission control electronic control unit (hereinafter referred to as ECT / ECU) 38 for performing a shift control of the transmission 36 is connected to a communication line 40.
Connected through. The VSC ECU 34 and E
Similarly to the engine ECU 20, the CT / ECU 38 includes a well-known microcomputer as a main part.

Here, the engine ECU 20 and the VSC · E
The CU 34 and the ECT / ECU 38 are configured to perform serial communication via the communication line 40 so as to share sensor signals input to each of them, control information calculated by each of them, and the like. And the VSC / ECU 34
A turning state of the vehicle is detected based on sensor signals from a lateral acceleration sensor 44 for detecting a lateral acceleration of the vehicle and a wheel speed sensor 46 provided on each wheel, and according to the detected turning state, Brake device (not shown)
And a target opening of the throttle valve 8 for performing VSC control (hereinafter referred to as a target opening by VSC control) to the engine ECU 20.
20 controls the opening of the throttle valve 8.

For example, when the vehicle tends to oversteer, a brake is applied to one of the left and right wheels to stabilize the vehicle attitude, and when an understeer occurs during the brake operation by the driver, the throttle valve 8 is turned on. Open and increase engine torque to stabilize vehicle attitude. Further, when the driver's operation amount of the accelerator pedal 22 (accelerator opening) is too large and power oversteer occurs, the throttle valve 8 may be forcibly closed.

On the other hand, the ECT / ECU 38 controls the signal from the shift switch 48 provided on the shift lever and the information obtained from the other ECUs 20 and 34 by serial communication (mainly, the accelerator opening from the engine ECU 20, V
The gear of the automatic transmission 36 is controlled in accordance with the vehicle speed calculated by the SC / ECU 34 based on the signal of the wheel speed sensor 46, and the target of the throttle valve 8 for controlling the automatic transmission to the engine ECU 20. The engine ECU transmits an opening degree (hereinafter referred to as a target opening degree by ECT control) to
20 controls the opening of the throttle valve 8.

For example, when the driver releases the accelerator pedal, the automatic transmission 36 is shifted down. At this time, the throttle valve 8 is opened to increase the engine torque so that sudden engine braking does not work. The throttle valve 8 may be closed to protect the automatic transmission 36.

The engine ECU 20 determines that the throttle opening detected by the throttle opening sensor 16 is
The motor 12 is driven so that the target opening of the throttle valve 8 is set internally. Normally, the target of the throttle valve 8 is controlled according to the accelerator opening detected by the accelerator opening sensor 24. When the vehicle speed setting switch 32 is pressed while the vehicle is traveling at a predetermined speed (for example, 60 km / h) or more, the vehicle speed at that time is stored, and the actual vehicle speed is stored in the stored vehicle speed. The automatic cruise control is performed to set the target opening of the throttle valve 8 such that In the following description, the target opening of the throttle valve 8 set according to the accelerator opening is referred to as a target opening based on the accelerator opening, and the target opening of the throttle valve 8 set for the auto cruise control. The opening is called a target opening by cruise control.

Further, the engine ECU 20 includes a VSC
When receiving the target opening by the VSC control from the ECU 34 or the target opening by the ECT control from the ECT / ECU 38, the received target opening is converted into the target opening and the cruise control based on the accelerator opening. Is used to drive the motor 12 in preference to the target opening degree.

On the other hand, the engine ECU 20 starts with the intake air amount of the engine 2 detected by the air flow meter 10, the engine speed detected by the speed sensor 26, the cooling water temperature detected by the water temperature sensor 28, and the air The fuel injection amount as the fuel supply amount to the engine 2 is calculated based on the oxygen concentration in the exhaust gas detected by the fuel ratio sensor 30, and the fuel injection valve 18 is driven according to the calculated fuel injection amount. By driving the fuel injection valve 18 in this manner, fuel corresponding to the calculated fuel injection amount is supplied to the engine 2.

Next, an engine ECU is used to drive the motor 12 (throttle valve 8) and the fuel injection valve 18.
The processing unique to the first embodiment executed in step 20 will be described with reference to the flowchart shown in FIG. still,
The process of FIG. 3 is repeatedly executed at predetermined time intervals (for example, every 8 ms).

As shown in FIG. 3, when the engine ECU 20 starts execution of the process, the first step (hereinafter, referred to as the first step) is executed.
At 110, the target opening of the throttle valve 8 used to drive the motor 12 is set in the following procedure. First, a target opening based on the accelerator opening is obtained in accordance with the accelerator opening detected by the accelerator opening sensor 24. Note that the target opening based on the accelerator opening is obtained by referring to a data map in the ROM 20b indicating the relationship between the accelerator opening and the target opening of the throttle valve 8.

At the time of auto cruise control, VSC
The target opening degree by the cruise control is determined so that the actual vehicle speed calculated by the ECU 34 based on the signal of the wheel speed sensor 46 becomes the vehicle speed set by operating the vehicle speed setting switch 32. Then, V from the VSC / ECU 34
When the target opening by the SC control and the target opening by the ECT control from the ECT / ECU 38 are not received, that is, the opening adjustment of the throttle valve 8 by the VSC control and the opening of the throttle valve 8 by the automatic transmission control. When the adjustment is not performed, the larger one of the target opening based on the obtained accelerator opening and the target opening based on the cruise control is set as the target opening used for driving the motor 12. Set.

When the target opening based on the ECT control is received from the ECT / ECU 38, the received ECT is given priority over the target opening based on the accelerator opening and the target opening based on the cruise control. The target opening by the control is set as the target opening used to drive the motor 12.

Further, from the VSC / ECU 34 to the VSC
When the target opening based on the control is received, the target opening based on the accelerator opening, the target opening based on the cruise control, and the target opening based on the ECT control are given priority over all the target openings. The target opening based on the VSC control is set as a target opening used to drive the motor 12.

In other words, the priority of the target opening actually used to drive the motor 12 is given the highest priority by the VSC control, and then the target opening by the ECT control is given priority. When the opening of the throttle valve 8 is not adjusted by the control and the automatic transmission control, the larger of the target opening based on the accelerator opening and the target opening based on the cruise control is given priority.

Although not shown, the engine EC
In U20, a motor drive process for driving the motor 12 is performed at predetermined time intervals in parallel with the process of FIG. 3, and the target opening of the throttle valve 8 set in S110 is determined by the motor drive process. Referenced in processing. By executing this motor driving process, the throttle opening detected by the throttle opening sensor 16 becomes equal to the S.
A drive signal is output to the motor 12 so that the target opening set at 110 is achieved.

In this embodiment, the VSC / ECU 3
4 calculates the actual vehicle speed based on the signal from the wheel speed sensor 46, and calculates the engine ECU 20 and the ECT / ECU 38
Adopts a configuration in which the vehicle speed is obtained by serial communication from the VSC / ECU 34, but the wheel speed sensor 46 or another vehicle speed sensor for detecting the vehicle speed is connected to the engine ECU.
20 and the ECT / ECU 38, respectively, and the engine ECU 20 and the ECT / ECU 38 may detect the vehicle speed by themselves.

Next, after setting the target opening of the throttle valve 8 in S110 as described above, in S120, S11 is executed.
From the target opening set at 0, as shown in FIG.
Using the data map stored in advance in b, the maximum injection amount as the upper limit of the fuel supply amount is determined. The data map of FIG. 2 shows the relationship between the target opening of the throttle valve 8 and the maximum injection amount, and the larger the target opening is set to the opening side, the larger the maximum injection amount becomes. It is to be set. FIG. 2 shows an image of the data map.
It is stored as binary data in M20b.

After the maximum injection amount is obtained in this manner, in subsequent S130, sensor signals from various sensors 26, 28, and 30 including the air flow meter 10 are fetched.
An operating state of the engine 2 such as an intake air amount is detected. Then, in S140, the fuel injection amount to the engine 2 is calculated based on the operating state such as the intake air amount detected in S130.

At S150, the fuel injection amount obtained at S140 is compared with the maximum injection amount obtained at S120. If the fuel injection amount is larger than the maximum injection amount, the routine proceeds to S150.
Proceeding to 160, the maximum injection amount determined in S120 is set as the fuel injection amount used to drive the fuel injection valve 18, and then the process ends.

If it is determined in S150 that the fuel injection amount obtained in S140 is not larger than the maximum injection amount, the process is terminated as it is.
The fuel injection amount obtained at 0 is set as the fuel injection amount used to drive the fuel injection valve 18.

Although not shown, the engine ECU 20 executes injection valve driving processing for driving the fuel injection valve 18 in parallel with the processing in FIG. 3 and in synchronization with the rotation of the engine 2. And the fuel injection valve 1 as described above.
The fuel injection amount set as the fuel injection amount used for driving the fuel injection valve 8 is referred to in the injection valve driving process. By executing the injection valve driving process, the fuel injection valve 18 is opened for a time corresponding to the set fuel injection amount, and the fuel is supplied to the engine 2.

In the first embodiment, the motor 12 corresponds to an actuator, and the VSC / ECU 34 performs processing for obtaining a target opening degree by VSC control and EC
The processing performed by the T-ECU 38 to determine the target opening by ECT control and the processing of S110 correspond to target opening setting means, and are provided for the engine ECU 20 to output a drive signal to the motor 12 by the engine ECU 20. The drive circuit and the above-described motor drive processing correspond to drive signal output means.
Steps S30 and S140 correspond to the fuel supply amount calculating means, and the processing of S120 corresponds to the upper limit value setting means.
The processing of 0 and S160 corresponds to the limiting means, and the fuel injection valve 18 and the above-described injection valve driving processing correspond to the fuel supply means.

As described in detail above, in the vehicle engine control apparatus according to the first embodiment, as shown in FIG. 4, a target opening based on the accelerator opening and a vehicle state other than the accelerator opening are used. Desired target opening by cruise control, V
One of the target opening by the SC control and the target opening by the ECT control is selected and set as the target opening of the throttle valve 8 used to drive the motor 12.

That is, auto cruise control, VSC control,
Normally, when the opening of the throttle valve 8 is not adjusted by the automatic transmission control, the target opening based on the accelerator opening is set as the target opening of the throttle valve 8, and the target based on the accelerator opening during the cruise control is set. If the target opening by the cruise control is larger than the opening, the vehicle tends to understeer or oversteer when turning, and
When adjusting the opening of the throttle valve 8 by SC control,
Alternatively, when the opening of the throttle valve 8 is adjusted in accordance with the shift control of the automatic transmission 36, the target opening by the cruise control irrespective of the accelerator opening, the target opening by the VSC control, and the target opening by the ECT control. One of the degrees
The target opening of the throttle valve 8 is set.

The maximum injection amount for limiting the fuel injection amount is increased in accordance with the target opening of the throttle valve 8 set as described above, as the target opening is set to the open side. The value is set to a value, and the fuel injection amount obtained according to the operating state of the engine 2 such as the intake air amount is limited to the maximum injection amount.

According to the vehicle engine control apparatus of the first embodiment, the drive control system for the throttle valve 8 including the motor 12 for driving the throttle valve 8 and the drive circuit for outputting a drive signal to the motor 12 is provided. Even if an abnormality occurs, the throttle valve 8 opens more than necessary and the intake air amount of the engine 2 increases, so that the fuel injection amount to the engine 2 is limited to the maximum injection amount according to the target opening of the throttle valve 8. Therefore, it is possible to prevent the engine torque from unnecessarily increasing.

Further, in the vehicle engine control device of the first embodiment, the maximum injection amount for limiting the fuel injection amount is set according to the target opening of the throttle valve 8. Therefore, auto cruise control, VS
When the C control and the automatic transmission control are performed and the target opening of the throttle valve 8 is set to the open side even though the accelerator opening is 0 (that is, the accelerator pedal 22 is fully closed), Also, the maximum fuel injection amount is set in accordance with the target opening, and an appropriate fuel injection amount is secured. Thus, an appropriate fuel injection amount can be obtained without causing a shortage of engine torque as in the related art disclosed in the above-mentioned publication. Engine torque can be obtained.

Therefore, according to the vehicle engine control apparatus of the first embodiment, a fail-safe function that the engine torque does not unnecessarily increase even if an abnormality occurs in the drive control system of the throttle valve 8; The automatic cruise control, the VSC control, and the automatic transmission control, which adjust the opening of FIG. 8 according to the vehicle state other than the accelerator opening, can be made compatible at a high level.

[Second Embodiment] Since the amount of intake air of the engine 2 changes with a delay with respect to the change of the target opening of the throttle valve 8, for example, the target opening of the throttle valve 8 during the VSC control is changed. If the maximum injection amount, which is the upper limit of the fuel injection amount, is suddenly set to the value when the target opening is fully closed when changing from fully open to fully closed, the actual intake air amount The fuel injection amount is running short and the engine 2
There is a possibility that a misfire may occur.

Therefore, with the configuration of the second embodiment described below, it is possible to reliably prevent the engine 2 from misfiring when the target opening of the throttle valve 8 suddenly changes to the closing side. The vehicle engine control device according to the second embodiment is different from the first embodiment in that the engine ECU 20 uses FIG.
Only in that the processing shown in FIG. Note that the processing in FIG. 5 is executed instead of the processing in FIG. 3, and this processing is also repeatedly executed at predetermined time intervals (for example, every 8 ms).

That is, when the engine ECU 20 starts executing the processing of FIG. 5, first in S210, S110 of FIG.
The target opening of the throttle valve 8 used to drive the motor 12 is set in exactly the same procedure as in the first embodiment. And the following S
At 220, the maximum injection amount is obtained from the target opening set at S210 using the data map shown in FIG. 2, as in S120 of FIG. 3, but in the second embodiment, the maximum injection amount is obtained. The maximum injection amount is changed to the provisional maximum injection amount tFMA.
Set as X.

Then, in the subsequent S225, the above-mentioned S220
From the temporary maximum injection amount tFMAX set in
Is used to find the maximum injection amount FMAXn that is actually used to limit the fuel injection amount in this process. In Equation 1, “α” is a constant preset to a value from 0 to 1, and “FMAXn−1” is the maximum injection amount obtained in the previous S225.

[0063]

FMAXn = (1−α) × FMAXn−1 + α × tFMAX (Equation 1) When the maximum injection amount FMAXn is obtained in this manner, in S230, the procedure is exactly the same as S130 in FIG. Then, the operating state of the engine 2 is detected.
Similar to S140 in FIG. 3, the fuel injection amount to the engine 2 is calculated based on the operating state such as the intake air amount detected in S230.

Then, in subsequent S250 and S260,
Similar to S150 and S160 in FIG. 3, a process for limiting the fuel injection amount is performed. Specifically, at S250,
The fuel injection amount obtained in S240 is compared with the maximum injection amount FMAXn obtained in S225, and the fuel injection amount is determined to be the maximum injection amount FMAXn.
If it is larger than MAXn, then in S260, S
The maximum injection amount FMAXn obtained in 225 is
8 is set as the fuel injection amount used to drive the motor 8, and then the process is terminated. In S250, S24
When it is determined that the fuel injection amount obtained at 0 is not larger than the maximum injection amount FMAXn, the process is terminated as it is, and accordingly, the fuel injection amount obtained at S240 drives the fuel injection valve 18. It is set as the fuel injection amount to be used.

That is, in the second embodiment, the above equation 1 is applied to the latest maximum injection amount tFMAX obtained according to the target opening of the throttle valve 8 to limit the fuel injection amount. By determining the actually used maximum injection amount FMAXn, the influence on the actual maximum injection amount FMAXn when the maximum injection amount tFMAX changes is suppressed. In other words, the maximum injection amount tFMAX
To set the actual maximum injection amount FMAXn.

According to the vehicle engine control device of the second embodiment, even when the target opening of the throttle valve 8 suddenly changes to the closing side during VSC control or the like, the maximum injection amount FMAXn is gently increased. Since the fuel injection amount changes (slowly decreases), the fuel injection amount to the engine 2 is prevented from becoming insufficient, and as a result, the engine 2 in the case where the target opening of the throttle valve 8 suddenly changes to the close side is changed. Misfire can be reliably prevented, and a greater effect can be obtained.

In the second embodiment, S in FIG.
Step 225 corresponds to the upper limit value change adjusting means. In the second embodiment, the maximum injection amount FMAXn is always gradually changed.
Only when the target opening degree changes to the close side, the processing of S225 may be executed to gradually change the maximum injection amount FMAXn (that is, to gradually decrease the maximum injection amount FMAXn).

[Third Embodiment] On the other hand, in order to prevent the engine 2 from misfiring when the target opening of the throttle valve 8 suddenly changes to the closing side, a third embodiment described below is used. Is also good. The vehicle engine control device according to the third embodiment is different from the first embodiment in that the engine ECU 20 is configured as shown in FIG.
Only in that the processing shown in FIG. Note that the processing in FIG. 6 is executed instead of the processing in FIG. 3, and this processing is also repeatedly executed at predetermined time intervals (for example, every 8 ms). In FIG. 6, the same processing contents as those in FIG. 3 are denoted by the same step numbers, and detailed description thereof will be omitted.

That is, as shown in FIG. 6, in the processing executed by the engine ECU 20 of the third embodiment, S1
After obtaining the fuel injection amount in 40, it is determined in subsequent additional S145 whether the target opening of the throttle valve 8 set in S110 has changed to the closing side, and the target opening has changed to the closing side. In this case, the processing of FIG. 6 is terminated without performing the processing for limiting the fuel injection amount in S150 and S160.

Also, according to the vehicle engine control device of the third embodiment, when the target opening of the throttle valve 8 suddenly changes to the closing side during VSC control or the like, the actual intake air amount is reduced. On the other hand, the fuel injection amount is prevented from becoming short, and as a result, misfire of the engine 2 can be prevented.

In the third embodiment, the processing in S145 in FIG. 6 corresponds to the restricted operation prohibiting means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an entire system configuration according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating a data map for setting a maximum fuel injection amount according to a throttle valve target opening.

FIG. 3 is a flowchart illustrating a process executed by an engine ECU of FIG. 1;

FIG. 4 is an explanatory diagram showing a procedure for setting a throttle valve target opening.

FIG. 5 is a flowchart illustrating a process executed by an engine ECU according to a second embodiment.

FIG. 6 is a flowchart illustrating a process executed by an engine ECU according to a third embodiment.

[Explanation of symbols]

2 ... engine 4 ... intake passage 6 ... exhaust passage 8
... Throttle valve 10 ... Air flow meter 12 ... Motor 14 ... Return spring 16 ... Throttle opening sensor 18 ... Fuel injection valve 20 ... Engine control electronic control unit (engine ECU)
20a CPU 20b ROM 20c RAM 22 accelerator pedal 24 accelerator opening sensor 26 rotational speed sensor
28 ... water temperature sensor 30 ... air-fuel ratio sensor 32 ... vehicle speed setting switch 34 ... VSC control electronic control unit (VSC / ECU)
36: automatic transmission 38: electronic control unit for transmission control (ECT / ECU)
Reference numeral 40: communication line 44: lateral acceleration sensor 46: wheel speed sensor 48
… Shift switch

Claims (3)

[Claims] 1. A throttle valve for adjusting an intake air amount of an engine mounted on a vehicle, an actuator for driving the throttle valve, and an accelerator pedal normally operated by a driver according to an operation amount of an accelerator pedal. A target opening degree of the throttle valve is set, and when the driving state of the vehicle becomes a predetermined specific state, the target opening degree of the throttle valve is determined according to a vehicle state other than the operation amount of the accelerator pedal. Target opening setting means for setting the degree, driving signal output means for outputting a driving signal corresponding to the target opening set by the target opening setting means to the actuator, and the engine including at least the intake air amount A fuel supply amount calculating means for calculating a fuel supply amount to the engine based on the operating state of the engine; An upper limit value setting unit that sets a larger value as the target opening is set to the opening side according to the target opening set by the degree setting unit, and the fuel supply amount calculated by the fuel supply amount calculating unit. The fuel supply amount is compared with the upper limit value set by the upper limit value setting means. If the calculated fuel supply amount exceeds the upper limit value, the fuel supply amount is limited to the upper limit value. A vehicle engine control device comprising: a limiting unit; and a fuel supply unit that supplies a fuel supply amount obtained through the limiting unit to the engine. 2. The vehicle engine control device according to claim 1, wherein the upper limit value setting means is provided when at least a target opening degree of the throttle valve set by the target opening degree setting means changes to a closing side. And an upper limit change adjusting means for gently changing the upper limit set by the limiting means and used by the limiting means. 3. The vehicle engine control device according to claim 1, wherein when the target opening of the throttle valve set by the target opening setting means changes to the closing side, the fuel by the restricting means is changed. An engine control device for a vehicle, comprising: a restriction operation prohibition unit that prohibits a restriction on a supply amount.