JP2005076552A - Internal combustion engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine control device preventing an internal combustion engine from running out of control or suddenly stopping at a time of occurrence of failure and securing good operation performance. <P>SOLUTION: This device is provided with intake air quantity limiting means 3, 4 individually limiting intake air quantity of each cylinder, an injection valve 6 individually supplying fuel to each cylinder, and an electronic control device 7 controlling the intake air quantity limiting means and the injection valve. The electronic control device 7 includes an intake air quantity regulating means individually regulating intake air quantity by controlling the intake air quantity limiting means 3, 4, an individual fuel quantity regulating means regulating fuel quantity by controlling the injection valve 6, and a failure determination means determining failures of the intake air quantity limiting means 3, 4, and makes a specific cylinder corresponding to failure determination shift to evacuation travel operation and increases or decreases intake air quantity of remaining normal cylinders in relation to normal operation state for compensation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for an internal combustion engine for an automobile, and more particularly to an internal combustion engine that improves safety during retreating when the intake air amount limiting means of the internal combustion engine fails and also improves drivability during the failure. The present invention relates to an engine control device.

Generally, an electronic throttle opening control means is used in an internal combustion engine control device.
The conventional electronic throttle opening control means is provided with a mechanism that allows the throttle valve to have a predetermined opening in order to ensure a minimum intake amount necessary for fully closed or evacuation travel in the event of a failure, or By providing a mechanism for returning the throttle valve to a fully closed state and providing a solenoid valve that bypasses the throttle valve, a structure is provided that can ensure safety when a failure occurs and can also retreat (see, for example, Patent Document 1). ).

  However, in the conventional evacuation traveling method as described above, since it is necessary to place importance on safety in deceleration and stopping, the intake air amount during evacuation traveling is relatively low enough to allow traveling in urban areas. It had to be set to a small intake amount, and it was difficult to secure a sufficient vehicle speed on highways and uphill roads.

On the other hand, in order to achieve both improved responsiveness and improved fuel efficiency, a throttle valve is provided for each cylinder, and the throttle downstream volume is set to be small, improving the responsiveness to the accelerator depression amount and improving the responsiveness between the cylinders. There has also been proposed an engine employing a so-called multiple throttle that suppresses intake interference, reduces pump loss, and improves fuel efficiency.
In addition, a system has been proposed in which the throttle valve disposed in each cylinder is configured by electronic throttle opening control means so that the opening can be controlled independently for each cylinder.

In this way, in a system in which the intake air amount limiting means for individually limiting the intake air amount to a plurality of cylinders is arranged in each cylinder, even if one intake air amount limiting means fails, the other intake air amount limiting means are normal. Therefore, further safety and traveling performance can be ensured in the retreat traveling.
However, in an internal combustion engine equipped with an intake air amount restricting unit that individually restricts the intake air amount to a plurality of cylinders, such as a multiple throttle system, safety and running performance during retreat travel when the intake air amount restricting unit fails. No control device has been proposed to achieve both.

Japanese Patent Laid-Open No. 10-121992

In the conventional internal combustion engine control device, there is a problem in that it is not possible to secure a sufficient vehicle speed on a highway or an uphill road because the intake air amount during retreat travel must be set to a relatively small intake air amount. .
In addition, in an internal combustion engine equipped with an intake air amount limiting means for individually limiting the intake air amount to a plurality of cylinders such as a multiple throttle system, safety and running performance during retreating when the intake air amount limiting means fails. However, there has been a problem that a specific method of realization has not been proposed, and it has been impossible to achieve both.

  The present invention has been made to solve the above-described problems. In an internal combustion engine provided with intake air amount restriction means for a plurality of cylinders, when the intake air amount restriction means fails, the safety during retreat travel can be improved. An object of the present invention is to obtain an internal combustion engine control device that achieves both running performance.

  An internal combustion engine control apparatus according to the present invention includes an intake air amount limiting unit that individually limits the intake air amount to a plurality of cylinders of an internal combustion engine, an injection valve that individually supplies fuel to each cylinder, an intake air amount limiting unit, and an injection valve The electronic control device includes an electronic control device for controlling the intake air amount adjusting means for individually adjusting the intake air amount to each cylinder by controlling the intake air amount restricting means, and an injection valve. A faulty intake air amount determined to be a failure by the failure determination means, including an individual fuel amount adjustment means for adjusting the amount of fuel supplied to each cylinder by controlling; and a failure determination means for determining a failure of the intake air amount restriction means The specific cylinder corresponding to the restricting means is shifted to the operation for retreat travel, and the other cylinders corresponding to the remaining normal intake amount restricting means are operated by increasing / decreasing the intake amount with respect to the normal operation state. Is shall.

  According to the present invention, when the intake air amount control means fails, only the specific cylinder corresponding to the occurrence of the failure is shifted to the retreat travel state, and the intake air amount of other cylinders passing through the normal intake air amount restricting means fails. By correcting according to the state, it is possible to prevent runaway or sudden deceleration when a failure occurs, and to make the total generated torque in line with the driver's intention and to ensure good driving performance.

Embodiment 1 FIG.
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.
1 is a block diagram schematically showing an internal combustion engine control apparatus according to Embodiment 1 of the present invention.
2 and 3 are flowcharts showing specific processing operations according to the first embodiment of the present invention. FIG. 2 shows intake air amount control processing, and FIG. 3 shows failure detection processing.

Further, FIG. 4 is an explanatory diagram showing torque loss (also referred to as pump loss) (refer to the shaded portion) generated in the first embodiment of the present invention, where the horizontal axis is the cylinder (cylinder) volume, and the vertical axis is the cylinder. The internal pressure is indicated.
Note that an arrow loop in FIG. 4 indicates a characteristic change between the cylinder internal volume and the cylinder internal pressure due to intake, compression, explosion (of a normal cylinder), and exhaust.

In FIG. 1, each intake pipe 2 communicates with each cylinder of an internal combustion engine (engine) 1.
Further, in each intake pipe 2 for each cylinder, a throttle valve 3 for individually limiting the intake amount, a throttle actuator 4 for opening and closing each throttle valve 3, and a throttle opening θ of each throttle valve 3 are detected. There are provided a throttle opening sensor 5 for performing the injection and an injection valve 6 for individually injecting fuel for each cylinder.
Each throttle actuator 4 and each injection valve 6 are connected to an electronic control unit (ECU) 7 and are driven by drive signals A and F from the electronic control unit 7, respectively.

The engine 1 is provided with a cylinder identification sensor 8 that generates a cylinder identification signal SGC in synchronization with the rotation of the engine 1. Each cylinder of the engine 1 is provided with an intake valve 9 and an exhaust valve 10.
Although not shown here, the engine 1 is provided with a water temperature sensor that detects the water temperature Tw of the cooling water, and the intake pipe 2 is an intake air that individually detects the intake air amount Qa supplied to each cylinder. A quantity sensor (air flow sensor) and an intake air temperature sensor for detecting intake air temperature (intake air temperature) Ta are provided, and an accelerator position sensor for detecting an accelerator opening α is provided in an accelerator pedal (not shown). It has been.

  The electronic control unit 7 includes detection information from various sensors indicating the operating state of the engine 1, that is, a cylinder identification signal SGC from the cylinder identification sensor 8, a throttle opening θ from the throttle opening sensor 5, and a water temperature sensor. The water temperature Tw, the intake air temperature Ta from the intake air temperature sensor, the intake air amount Qa from the intake air amount sensor, and the accelerator opening α are input from the accelerator position sensor.

Here, typically, the case where the engine 1 is an in-line four-cylinder engine is taken as an example, and as an intake air amount restriction means for restricting the intake air amount for each cylinder individually, the intake pipe 2 of each cylinder is independently provided. The case where the throttle valve 3 and the throttle actuator 4 to be driven are applied is shown.
In FIG. 1, in order to avoid complexity, the peripheral configuration of only the first cylinder of the engine 1 is typically shown, but the same applies to the other (second to fourth) cylinders of the engine 1. Needless to say, it is composed.

Next, the intake air amount control processing operation and the failure detection operation according to the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIGS.
The control processing shown in FIGS. 2 and 3 is executed mainly by the electronic control unit 7.
First, the intake air amount control process shown in FIG. 2 will be described.
First, the electronic control unit 7 indicates the operating state of the engine 1 such as the engine speed Ne based on the cylinder identification signal SGC, the intake amount Qa of each cylinder, the throttle opening θ and the accelerator opening α of each throttle valve 3. Various sensor information is detected (step S101), and a failure of each electronic throttle opening control means (intake amount restriction means) including the throttle valve 3 for each cylinder is detected based on the various sensor information (step S102).
The specific failure detection process in step S102 will be described later with reference to FIG.

  Subsequently, it is determined whether or not a failure has been detected in step S102 (step S103). If it is determined that a failure has been detected (ie, YES), processing for retreat travel (steps S104 to S111) is executed. If it is determined that no failure has been detected (that is, NO), the required torque of each cylinder is calculated as normal control (step S112), and the process proceeds to the process described later (step S113 and subsequent steps).

Here, the evacuation travel processing (steps S104 to S111) when a failure is detected in step S103 (when a failure occurs) will be described in detail.
First, in order to determine the failure state of the throttle valve 3 (intake amount restriction means) in which a failure has been detected, whether or not the opening degree θF of the throttle valve 3 in which the failure has been detected is greater than a predetermined value (allowable upper limit value) β. Is determined (step S104).

The reason for determining the failure state in step S104 is as follows.
In general, when a failure of the electronic throttle opening control means occurs, in the conventional method, the energization to the throttle actuator 4 is stopped, and the throttle opening θ is fully closed (= 0 by the action of a spring or the like. ) Or an intermediate predetermined opening degree to shift to a state for retreat travel.

  However, according to the above method, when an electrical failure occurs in the throttle actuator 4 or the like, it is possible to shift to a state for retreat travel, but the throttle valve 2 becomes inoperable due to a mechanical change such as a foreign object biting in. If this happens, there may be a situation where it is not possible to shift to the state for retreat travel.

Considering such a case, it is important to determine the failure state of the throttle valve 3 when the failure is detected, and it is matched with the failure state of the throttle valve 3 (or the throttle actuator 4 or the like). Thus, it is understood that it is necessary to select the control during the retreat travel.
In order to specifically determine the failure state, it is necessary to determine whether or not the opening degree θF of the failure throttle valve is larger than a predetermined value β as in step S104 in FIG.

  If it is determined in step S104 that θF> β (that is, YES), the processing in steps S105 to S107 is executed, and if it is determined that θF ≦ β (that is, NO), the processing in steps S108 to S110. Execute.

Here, the predetermined value serving as the determination criterion for the failure state corresponds to a threshold value for determining whether or not to continue supplying fuel to a specific cylinder (failed cylinder) corresponding to the failed throttle valve, as will be described later. It is desirable to variably set according to the operating state of the engine 1.
The variable setting of the predetermined value can be easily realized by, for example, map calculation such as referring to a numerical table with the engine speed Ne as the horizontal axis and the accelerator opening α as the vertical axis.

If it is determined in step S104 in FIG. 2 that θF> β (that is, YES), the electronic control unit 7 stops the fuel supply to the failed cylinder (step S105).
This is because if an amount of fuel corresponding to the throttle opening θF (intake amount) larger than the predetermined value β is supplied, the torque generated from the failed cylinder becomes too large, causing problems such as sudden acceleration or runaway of the vehicle. This is to prevent this.

Subsequently, the electronic control unit 7 calculates a loss torque of the failed cylinder (step S106).
This is because the failure cylinder does not generate torque due to the stop of fuel supply (step S105), but torque loss occurs as shown by the hatched portion in FIG. 4, and therefore, based on the loss torque by calculating the torque loss value. This is to enable calculation of required torque (step S111 described later) in other cylinders (normal cylinders).

By the way, in step S105, by stopping the fuel supplied to the failed cylinder, the sucked air is exhausted as it is from the failed cylinder. Therefore, with this state, the air-fuel ratio in the exhaust gas becomes lean (oxygen-excess state), the exhaust gas purification capacity of the three-way catalyst in the exhaust pipe decreases, and a large amount of unpurified exhaust gas may be discharged. is there.
In order to prevent this, it is only necessary to enrich the air-fuel ratio of the normal cylinder and set the lean exhaust gas in the vicinity of the stoichiometric air-fuel ratio.

Therefore, the electronic control unit 7 calculates an A / F (air-fuel ratio) correction coefficient for enriching the normal cylinder (step S107), and proceeds to step S111.
At this time, since the intake amount of the failed cylinder is larger than the predetermined value, if the exhaust gas is set to the stoichiometric air-fuel ratio when the intake amount of the normal cylinder is small, the A / F correction coefficient of the normal cylinder is equal to the combustible air-fuel ratio. It may be necessary to enrich beyond the range. In this case, forcibly correcting the A / F causes misfires and the like, and the correction coefficient is fixed to “1.0” and the correction is prohibited.

On the other hand, if it is determined in step S104 that θF ≦ β (that is, NO), it is determined to continue supplying fuel to the failed cylinder (step S108).
This is because the state of θF ≦ β means that the amount of intake air taken into the failed cylinder is small, and the generated torque is small even if the amount of fuel corresponding to this intake amount is supplied and burned in the failed cylinder. Therefore, even if a failure occurs, sudden acceleration or runaway of the vehicle is unlikely to occur, and there is no problem from the viewpoint of safety even if fuel supply is continued, and fuel is supplied to maintain good running performance during evacuation It is because it can be said that it is more preferable to continue.

Subsequently, the electronic control unit 7 calculates the generated torque of the failed cylinder (step S109).
In the calculation process (step S106) in the case of the above (θF> β), the “loss torque” of the failed cylinder is calculated. In this case (θF ≦ β), fuel is supplied to the failed cylinder. Calculate “generated torque” commensurate with the quantity.

Subsequently, the electronic control unit 7 sets the A / F correction coefficient of the normal cylinder to “1.0” to prohibit A / F correction (step S107), and proceeds to step S111.
This is because in this case, since the fuel is supplied to the failed cylinder and burned, it is not necessary to correct the A / F of the normal cylinder so that the air-fuel ratio of the exhaust gas matches the stoichiometric air-fuel ratio.

When the selection process corresponding to the failure throttle state is completed as in steps S104 to S110, the electronic control unit 7 calculates the torque (requested torque) to be generated in the normal cylinder (step S111).
Specifically, in step S111, first, a basic required torque that should be generated in the entire engine 1 is calculated based on the accelerator opening α and the engine speed Ne, and the basic required torque is calculated in step S106. The total required torque that should be generated only in the normal cylinders is calculated by adding the generated loss torque and subtracting the generated torque calculated in step S109, and dividing the total required torque by the number of normal cylinders. A required torque per cylinder of the cylinder is calculated.

Next, the correction value of the required torque for each cylinder is calculated from the variation for each cylinder, the intake air temperature Ta, the water temperature Tw, etc., and the required intake air amount for each cylinder is calculated (step S113).
Further, the target throttle opening degree θo of each cylinder is calculated based on the corrected required torque for each cylinder (step S114), the throttle actuator 4 is driven, and the throttle opening degree θ is set to the target throttle opening degree. It is made to correspond to (theta) o (step S115), the processing routine of FIG. 2 is complete | finished, and it returns.
However, the throttle valve that is determined to be in failure is deenergized as described above by stopping energization of the throttle actuator 4.

Next, the failure detection process corresponding to step S102 in FIG. 2 will be described in detail with reference to FIG.
First, an initial value “1” is set to the cylinder number N (step S201), and the following processing (steps S202 to S208) is repeatedly executed for the total number of cylinders (N = 1 to 4).

First, it is determined whether or not the actual throttle opening θN of the throttle valve 3 corresponding to the cylinder number N can be controlled within a predetermined range (± Δθ) centered on the target throttle opening θo (step S202). .
In step S202, if it is determined that the throttle opening θN of the Nth cylinder can be controlled within the predetermined range Δθ from the target throttle opening θo (that is, YES), an initial value is set in the failure determination timer TMF (N). After setting (step S203), the process proceeds to the next determination process (step S207).

The failure determination timer TMF (N) is set for each cylinder, and the initial value of each is determined in advance for each cylinder.
For the initial value of the failure determination timer TMF (N), for example, refer to a multi-dimensional numerical table centered on the cooling water temperature Tws of the engine 1 at the start, the current engine cooling water temperature Tw, the intake air temperature Ta, etc. By doing so, it can be set as map data.

  The reason why the temperature parameters Tws, Tw, and Ta are used for the initial value setting is that, for example, when the throttle valve 3 does not operate due to a foreign object or the like, it is necessary to determine that a failure has occurred. This is because an initial value needs to be set as a temperature-related value so as not to determine that a failure has occurred, for example, when ice is attached around the throttle valve 3 during parking during the temperature period and temporarily stops operating.

  The reason why the initial value of the failure determination timer TMF (N) is set for each cylinder is, for example, when the engine 1 is a four-cylinder engine, on the inner side of the cylinders at both ends (first and fourth). This is because the temperature conditions are considered to be different, for example, the temperature of the (second and third) cylinders is likely to increase in temperature.

When the throttle opening θN of the Nth cylinder is larger than the predetermined value β, the initial value of the failure determination timer TMF (N) needs to be set to a smaller value than when the throttle opening θN is not larger than the predetermined value β.
This is because a failure on the fully open (maximum opening) side that is likely to lead to runaway or the like should be detected (judged) as soon as possible. This is because the prevention of misjudgment should be emphasized rather than early failure judgment.

  On the other hand, if it is determined in step S202 that the throttle opening θN of the Nth cylinder is not controlled within the predetermined range Δθ from the target throttle opening θo (that is, NO), a failure determination timer corresponding to the Nth cylinder. It is determined whether TMF (N) has been counted down to “0” (the failure state has continued for a predetermined period) (step S204).

If it is determined in step S204 that TMF (N) = 0 (that is, YES), the failure flag FF (N) is set (step S205), and the process proceeds to step S207.
On the other hand, in step S204, if failure determination timer TMF (N) is not counted down to “0” and it is determined that TMF> 0 (that is, NO), failure determination timer TMF (N) is decremented ( Step S206), the process proceeds to Step S207.

When the processes of steps S202 to S206 are completed, it is finally determined whether or not the processes have been completed for all cylinders (step S207).
In this case, since a 4-cylinder engine is assumed, it is determined whether or not the cylinder number N = 4.
If it is determined in step S207 that N = 4 (that is, YES), the processing routine of FIG. 3 is terminated and the process returns.

  On the other hand, if it is determined in step S207 that N <4 (that is, NO), 1 is added (incremented) to the cylinder number N (step S208), and the process returns to step S202. S202 to S206 are repeatedly executed.

In this way, the failure determination of the individual intake air amount limiting means (throttle valve 3, throttle actuator 4, etc.) is performed, and only the specific cylinder corresponding to the determined failure is shifted to the driving for retreat travel, and the failure state The control for the evacuation travel of the failed cylinder is switched according to the normal operation state, and the intake amount and the fuel amount with respect to the normal operation state are corrected for increase and decrease for the other normal cylinders, while ensuring safety at the time of the failure, The drivability can also be kept good.
In addition, when the throttle function shows a malfunctioning state for a predetermined period, it is determined that there is a failure, and depending on the environment in which each throttle is installed (particularly, the environment related to temperature), the malfunctioning condition, and each cylinder By setting the period for failure determination (failure determination timer TMF (N)) individually according to the installation conditions, operating conditions, environmental conditions, etc. The determination can be made, and the safety when a failure occurs can be further improved.

In other words, when a throttle failure is determined, the amount of intake air that passes through the normal throttle is corrected according to the state of the failed cylinder, so that runaway or sudden deceleration at the time of the failure can be reliably prevented and the engine 1 Can be controlled in accordance with the driver's intention, and good driving performance can be ensured.
In addition, the amount of fuel supplied to normal cylinders is corrected to increase so that the air-fuel ratio of exhaust gas in the entire engine including the failed cylinder corresponds to the stoichiometric air-fuel ratio. Can be suppressed.

Embodiment 2. FIG.
In the first embodiment, in the failure state determination process (step S104), the failure throttle opening θF is compared with only the allowable upper limit value (first predetermined value β). Or a predetermined value of 2).
FIG. 5 is a flowchart showing an intake air amount control process according to the second embodiment of the present invention in which failure mode determination is performed based on the first and second predetermined values.
FIG. 6 is an explanatory diagram showing torque loss (see the shaded area) that occurs in the case of “fully closed side failure” according to Embodiment 2 of the present invention, and corresponds to FIG. 4 described above.

In FIG. 5, the failure mode determination process (step S304) corresponds to the above-described step S104. In addition, about the process (step S101-S103, S105-S115) similar to the above-mentioned (refer FIG. 2), the same code | symbol as the above is attached | subjected, or "A" is attached after a code | symbol, and detailed description is abbreviate | omitted. To do.
In this case, the overall configuration according to the second embodiment of the present invention is as shown in FIG. 1, and the failure detection process is as shown in FIG.

Also in this case, the intake air amount control process (FIG. 5) and the failure detection process (FIG. 3) are executed mainly by the intake air amount control means in the electronic control unit 7 (see FIG. 1).
Hereinafter, the intake air amount control process according to the second embodiment of the present invention will be described with reference to FIG.
In FIG. 5, basically the same processing as described above (FIG. 2) is executed, and only step S304 is different from the above.
Further, since the processing results of steps S106A and S107A are slightly different in relation to step S304, the description will be given focusing on steps S304, S106A and S107A.

Following failure detection processing (step S102) similar to that described above, if a failure is determined in step S103, it is determined in step S304 what state (mode) the failure detected in step S102 is. .
Specifically, the case is classified into three cases, and when the throttle opening θF determined to be failure is larger than the first predetermined value β (allowable upper limit value), it is determined as “full-open failure”. If the first predetermined value β is equal to or smaller than the second predetermined value γ (allowable lower limit value <β), it is determined as “intermediate opening failure”, and if it is smaller than the second predetermined value γ, Determined as “fully closed fault”.

If it is determined in step S304 that the “fully closed side failure” or “fully opened side failure” has occurred, the process proceeds to step S105 described above to stop the fuel supply, and then the processing in steps S106A and S107A is executed. .
In this case, the point that steps S105 to S107A are executed also in the case of “fully closed side failure” is different from the above.

In the above description, it is preferable that the fuel supply is continued because the risk of runaway is less when the failure throttle opening θF is equal to or less than the predetermined value β. However, the failure throttle opening θF is almost fully closed. In the case of (θF <γ), the amount of intake air into the failed cylinder becomes very small. Therefore, particularly in a region where the engine speed Ne is high, combustion is likely to become unstable and may cause misfire.
Therefore, in the case of the “fully closed side failure”, it is considered that the operation state is more stable when the fuel supply is stopped. Therefore, the fuel supply is stopped even when the opening degree is close to the fully closed state.
It should be noted that the first and second predetermined values β and γ used for the mode determination in step S304 are desirably variably set according to the operating state of the engine 1 as described above.

  On the other hand, if it is determined in step S304 that “intermediate opening failure”, the fuel supply is continued in step S108 and the steps S109 and S110 are executed as described above.

Here, since the calculation results in steps S106A and S107A differ between "fully closed side failure" and "fully open side failure", a supplementary explanation will be given.
That is, the calculation results of steps S106A and S107A are the same as those described above in the case of “fully open side failure”, but in the case of “fully closed side failure”, the loss torque of the failed cylinder in step S106A is as shown in FIG. As shown by the shaded portion of, it is much larger than in the case of “full open side failure” (shaded portion in FIG. 3).
Therefore, in this case, it is necessary to set the intake air amount to be corrected in the normal cylinder larger than the above.

  On the other hand, regarding the A / F correction processing of the normal cylinder in step S107A, in this case, the opening degree θF of the failed throttle is almost fully closed, and the amount of air discharged from the failed cylinder is small. Is less.

  As described above, it is possible to prevent the combustion from becoming unstable when the throttle opening degree θF is nearly fully closed only by changing a part of the intake air amount control process (step S304). Therefore, the evacuation travel at the time of failure can be further made safer, further excellent driving performance can be secured, and exhaust gas deterioration can be further suppressed.

Embodiment 3 FIG.
In the first embodiment (see FIG. 1), the throttle valve 3 and the throttle actuator 4 provided in the intake pipe 2 are used as the individual intake air amount limiting means for each cylinder, but the intake valve 9 is provided. A valve actuator may be used.
FIG. 7 is a block diagram showing a third embodiment of the present invention in which the valve actuator 11 is used as the intake air amount restricting means. The same components as those described above (see FIG. 1) are denoted by the same reference numerals as those described above. Or, “B” is added after the reference numeral, and the detailed description is omitted.

In FIG. 7, only the first cylinder of the engine 1 is shown as a representative, but the other second to fourth cylinders are configured similarly.
In FIG. 7, a valve actuator 11 (intake amount restriction means) provided at one end of the intake valve 9 is an electronic direct acting valve that electronically controls the valve opening period, valve opening timing or valve opening operation amount of the intake valve 9. It is comprised by the control means and is driven by the drive signal Va from the electronic control unit 7B.

The valve actuator 11 is provided with a lift amount sensor 12 for detecting the lift amount L of the intake valve 9, and the lift amount L detected by the lift amount sensor 12 is input to the electronic control unit 7B. .
In this case, the intake air amount Qa supplied to each cylinder is limited by the valve actuator 11.

Also in this case, when the valve actuator 11 corresponding to any one of the four cylinders fails, according to the processing procedure described above (see FIGS. 2 and 3), the evacuation traveling operation according to the failure state is performed by the failed cylinder, The intake air amount and the supplied fuel to the normal cylinder having the remaining normal valve actuator 11 are corrected. As a result, the same effects as described above can be obtained.
That is, it can be easily realized by replacing the “throttle opening” described in each procedure in FIGS. 2 and 3 with “the amount of intake air passing through the intake valve 9”.

It is a block block diagram which shows Embodiment 1 of this invention. It is a flowchart which shows the throttle (intake amount) control processing operation | movement by Embodiment 1 of this invention. It is a flowchart which shows the failure detection processing operation by Embodiment 1 of this invention. It is explanatory drawing which shows the pump loss (torque loss) of the specific cylinder corresponding to the throttle full open side failure by Embodiment 1 of this invention. It is a flowchart which shows the throttle (intake amount) control processing operation | movement by Embodiment 2 of this invention. It is explanatory drawing which shows the pump loss of the specific cylinder corresponding to the throttle full close side failure by Embodiment 2 of this invention. It is a block block diagram which shows Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Engine (internal combustion engine), 2 Intake pipe, 3 Throttle valve, 4 Throttle actuator, 5 Throttle opening sensor, 6 Injection valve, 7, 7B Electronic control unit, 8 cylinder identification sensor, 9 Intake valve, 10 Exhaust valve, 11 Valve actuator, 12 Lift sensor, A, F, Va Drive signal, L Lift, Qa Intake, Tw Water temperature, Ta Intake temperature, α accelerator opening, θ throttle opening, θo Target throttle opening, β Predetermined value .

Claims (16)

Intake air amount limiting means for individually limiting the intake air amount to a plurality of cylinders of the internal combustion engine;
An injection valve for individually supplying fuel to each cylinder;
An internal combustion engine control device comprising: the intake air amount limiting means and an electronic control device that controls the injection valve;
The electronic control device
An intake air amount adjusting means for individually adjusting the intake air amount to each cylinder by controlling the intake air amount limiting means;
Individual fuel amount adjusting means for adjusting the amount of fuel supplied to each cylinder by controlling the injection valve;
Failure determination means for determining failure of the intake air amount restriction means,
The specific cylinder corresponding to the failure intake amount restriction means determined to be a failure by the failure determination means is shifted to the retreat travel operation, and other cylinders corresponding to the remaining normal intake amount restriction means are An internal-combustion-engine control apparatus that operates by correcting an increase or decrease in an intake air amount with respect to an operating state.   2. The internal combustion engine control device according to claim 1, wherein the electronic control device executes the operation for the retreat travel by cutting off a fuel supply to the specific cylinder.   The electronic control unit sets a first predetermined value corresponding to an allowable upper limit value of the intake air amount, and the specific control is performed when the amount of air passing through the failed intake air amount limiting means is larger than the first predetermined value. 3. The internal combustion engine control device according to claim 2, wherein the fuel supply to the cylinder is cut off.   The electronic control unit sets a second predetermined value that is smaller than the first predetermined value and corresponds to an allowable lower limit value of the intake air amount, and the amount of air passing through the failed intake air amount limiting means is the second 4. The internal combustion engine control device according to claim 3, wherein when less than a predetermined value, fuel supply to the specific cylinder is cut off.   5. The internal combustion engine control device according to claim 3, wherein the electronic control device sets the first or second predetermined value according to an operating state of the internal combustion engine. 6.   The electronic control device operates by correcting the intake amount of the other cylinders to be increased so as to compensate for the loss generated in the specific cylinder when the fuel supply to the specific cylinder is shut off. The internal combustion engine control device according to any one of claims 2 to 5.   When the electronic control unit shuts off the fuel supply to the specific cylinder, the electronic control unit corrects the fuel amount of the other cylinders by an amount corresponding to the amount of air flowing from the specific cylinder into the exhaust system of the internal combustion engine. The internal combustion engine control device according to any one of claims 2 to 5, wherein the internal combustion engine control device is operated.   The electronic control unit is configured to operate with the intake air amount of the other cylinders corrected to increase or decrease in accordance with the torque generated in the specific cylinders when the fuel supply to the specific cylinders is continued. The internal combustion engine control device according to any one of claims 2 to 5.   9. The internal combustion engine control device according to claim 1, wherein the failure determination unit determines that a failure occurs when the intake air amount restriction unit has failed for a predetermined period. . The intake air amount restricting means comprises a plurality of intake air amount restricting means for individually restricting the intake air amount to each cylinder,
10. The internal combustion engine control device according to claim 9, wherein the predetermined period is individually set for each intake air amount restriction unit.   11. The internal combustion engine control device according to claim 9, wherein the predetermined period is variably set according to a parameter corresponding to a temperature of each intake air amount restriction unit.   The predetermined period is set according to at least one of a first parameter corresponding to a temperature at the start of each intake air amount restriction unit and a second parameter corresponding to a current temperature. Item 12. The internal combustion engine controller according to Item 11.   10. The internal combustion engine control device according to claim 9, wherein the predetermined period is variably set in accordance with a malfunctioning state of each intake air amount limiting unit.   The predetermined period is shortened when the amount of air passing through the malfunctioning intake air amount limiting means is greater than a predetermined value, and the amount of air passing through the malfunctioning intake air amount limiting means is reduced. 14. The internal combustion engine control device according to claim 13, wherein the control is extended when the amount is smaller than the predetermined value. The intake air amount limiting means is
A throttle valve individually provided in each intake pipe communicated with each cylinder individually;
The internal combustion engine control device according to any one of claims 1 to 14, characterized by comprising: a throttle actuator that opens and closes the throttle valve.   The internal combustion engine control device according to any one of claims 1 to 14, wherein the intake air amount limiting means is configured by a valve actuator provided individually for an intake valve of each cylinder. .

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