JP2004060601A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure an optimum EGR control amount by correcting a VNT opening (throttling amount) when it is difficult to achieve the target of the EGR control amount by an EGR valve 9. <P>SOLUTION: An ECU2 corrects the VNT opening when the target EGR control amount (for example, A/F) cannot be achieved despite the fact that the EGR valve 9 is generally fully open. Specifically, the corrected amount of the VNT opening is calculated according to the deviation of a fresh air amount measured by AFM10 to the target value, and the VNT opening (instruction opening of VNT or drive current) is corrected by the corrected amount (throttling amount is increased). Thus, since an exhaust pressure (on the upstream side of an exhaust turbine 5) in an exhaust passage 4 is increased, the EGR amount is increased, and the target EGR control amount can be assured. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for an internal combustion engine that includes a variable capacity turbocharger and performs EGR for returning a part of exhaust gas to an intake system.
[0002]
[Prior art]
Conventionally, in an engine with a VNT (variable capacity turbocharger), when performing EGR for returning a part of exhaust gas to an intake system, the VNT is set for each engine operating condition (engine speed and injection amount). Based on the target intake pressure, the intake pressure F / B control for controlling the VNT opening (throttle amount) or the VNT drive current is performed. Alternatively, open control for driving the VNT based on a VNT base opening, a VNT drive current, or the like set for each operating condition is performed.
[0003]
Further, the EGR, based on the target value of the EGR control amount set for each operating condition (EGR amount, EGR rate, A / F, the fresh air amount, the exhaust _{O 2} concentration and the intake _{O 2} concentration), EGR valve Is controlled by F / B.
That is, the amount of gas flowing into the cylinder represented by the intake pressure is controlled by the VNT, and the amount of EGR and the like are controlled by the EGR valve, thereby realizing optimum exhaust gas characteristics for each operating condition.
[0004]
[Problems to be solved by the invention]
However, the VNT opening and the intake pressure sensor vary due to machine differences and changes over time, and the actual value differs from the output value. That is, the VNT opening takes an opening different from the preset value with respect to the command opening and the command current, and the intake pressure sensor outputs a value different from the actual intake pressure.
For this reason, when the VNT is controlled to be open, if the VNT opening varies, the actual throttle amount of the VNT becomes insufficient, the exhaust pressure becomes insufficient, and a sufficient EGR amount may not be obtained. At this time, the EGR valve is controlled so as to increase the EGR amount so as to satisfy the target value. However, when the variation amount of the VNT is large, the EGR amount is sufficiently increased even when the EGR valve is fully opened. And the target value of the EGR control amount cannot be satisfied.
[0005]
On the other hand, when the intake pressure F / B control is performed on the VNT, the same occurs because the intake pressure sensor varies.
Further, when the intake pressure F / B control is being performed, the target value of the EGR control amount may not be satisfied in the following cases.
That is, an operating condition (per unit time) in which the change amount of the intake pressure with respect to the change amount of the VNT opening such as the low rotation speed and the low load range is much smaller than the change amount of the EGR control amount with respect to the change amount of the VNT opening. When the intake pressure is controlled to a value sufficiently close to the target value when the VNT is controlled under the intake pressure F / B under the operating conditions when the cylinder inflow gas amount is small and the absolute value of the intake pressure is small). In some cases, the throttle amount of the VNT is insufficient in view of the EGR control amount, and the target value of the EGR control amount cannot be satisfied in the same manner as described above.
[0006]
This is likely to occur particularly when a dead zone is provided in the value of the intake pressure for control stability. That is, as shown in FIG. 3, if the target intake pressure has a certain width (dead zone), the VNT restriction amount differs between the lower limit value and the upper limit value of the target intake pressure. When it is small (the VNT opening is large) (in the case of the VNT opening A in FIG. 3), as shown in FIG. 4, the target value of the EGR control amount (A / F in FIG. 4) can inevitably be achieved. Disappears. The reason for this is that, when the throttle amount A of the VNT is compared with the throttle amount B, the exhaust pressure of the throttle amount A is lower than that of the throttle amount B, and as a result, the EGR amount Is reduced.
As described above, when the EGR control amount cannot satisfy the target value, there is a problem that the emission deteriorates.
The present invention has been made based on the above circumstances, and an object thereof is to secure an optimal EGR control amount by correcting a VNT opening when it is difficult to achieve a target of an EGR control amount by an EGR valve. An object of the present invention is to provide a control device for an internal combustion engine.
[0007]
[Means for Solving the Problems]
(Invention of claim 1)
The present invention provides an internal combustion engine provided with a variable capacity turbocharger that varies the throttle amount, controls the throttle amount of the turbocharger, and controls the EGR valve opening that returns a part of exhaust gas to an intake system. Control device,
When the operation amount of the EGR valve is determined to be equal to or more than the predetermined value C1 and the deviation of the EGR control amount from the target value is determined to be equal to or more than the predetermined value C2, the throttle amount is increased in a direction in which the exhaust pressure of the turbocharger increases. Is corrected.
[0008]
If the throttle amount is corrected (increased throttle amount) in the direction in which the exhaust pressure increases (in general, the boost pressure increases), the EGR amount increases with the increase in the exhaust pressure. If the deviation from the target value of the EGR control amount is equal to or greater than the predetermined value C2 (if it is difficult to achieve the target of the EGR control amount by the EGR valve), the turbocharging is performed even though the amount is equal to or greater than the predetermined value C1. By correcting the throttle amount of the machine, it is possible to secure an optimal EGR control amount.
[0009]
(Invention of claim 2)
The present invention includes a variable-capacity turbocharger that varies a throttle amount, and performs an EGR valve that feedback-controls a throttle amount of the turbocharger based on a target intake pressure and returns a part of exhaust gas to an intake system. A control device for an internal combustion engine that controls an opening degree,
When it is determined that the operation amount of the EGR valve is equal to or more than the predetermined value C1 and the deviation of the EGR control amount from the target value is equal to or more than the predetermined value C2, the feedback control of the turbocharger is stopped and the turbocharger is stopped. The throttle amount is corrected in a direction in which the exhaust pressure of the feeder increases.
[0010]
When the throttle pressure of the turbocharger is controlled by the intake pressure feedback and the intake pressure sensor varies, the EGR amount cannot be sufficiently increased even when the EGR valve is fully opened, and the target EGR control is not performed. We may not be able to secure the quantity. Therefore, when it is difficult to achieve the target of the EGR control amount by the EGR valve (when the deviation from the target value of the EGR control amount is equal to or more than the predetermined value C2 even though the operation amount of the EGR valve is equal to or more than the predetermined value C1) In this case, by stopping the intake pressure feedback control of the turbocharger, it is possible to remove the adverse effect on the EGR control amount due to the intake pressure feedback control.
Further, if the throttle amount is corrected (increased throttle amount) in the direction in which the exhaust pressure increases (in general, the boost pressure increases), the EGR amount increases with the increase in the exhaust pressure. When it is difficult to achieve the target of the EGR control amount by the above, it is possible to secure the optimum EGR control amount by correcting the throttle amount of the turbocharger.
[0011]
(Invention of claim 3)
The control device for an internal combustion engine according to claim 1 or 2,
When correcting the aperture amount, the correction amount is calculated according to the deviation of the EGR control amount from the target value.
In this case, since the correction amount can be obtained in accordance with the degree of variation in the aperture amount, it is possible to control the EGR control amount to the target value.
[0012]
(Invention of Claim 4)
The control device for an internal combustion engine according to claim 1 or 2,
When correcting the aperture amount, the correction amount is set to a predetermined constant value.
In this case, since it is not necessary to calculate and calculate the correction amount each time, the control logic can be simplified.
[0013]
(Invention of claim 5)
The present invention includes a variable-capacity turbocharger that varies a throttle amount, and performs an EGR valve that feedback-controls a throttle amount of the turbocharger based on a target intake pressure and returns a part of exhaust gas to an intake system. A control device for an internal combustion engine that controls an opening degree,
The feedback control of the turbocharger is stopped when the operation amount of the EGR valve is determined to be equal to or more than the predetermined value C1 and the deviation of the EGR control amount from the target value is determined to be equal to or more than the predetermined value C2. I do.
[0014]
When the throttle pressure of the turbocharger is controlled by the intake pressure feedback and the intake pressure sensor varies, the EGR amount cannot be sufficiently increased even when the EGR valve is fully opened, and the target EGR control is not performed. We may not be able to secure the quantity. Therefore, when it is difficult to achieve the target of the EGR control amount by the EGR valve (when the deviation from the target value of the EGR control amount is equal to or more than the predetermined value C2 even though the operation amount of the EGR valve is equal to or more than the predetermined value C1) In this case, by stopping the intake pressure feedback control of the turbocharger, it is possible to remove the adverse effect on the EGR control amount due to the intake pressure feedback control.
[0015]
(Invention of claim 6)
The control device for an internal combustion engine according to claim 5,
In advance, throttle amount control data that is a predetermined throttle amount of the turbocharger corresponding to each operating condition is stored, and when feedback control of the turbocharger is stopped, the control data immediately after the stop is stored. It is characterized in that it is kept open or open control is performed by applying aperture control data.
Also in this case, similarly to the invention of the fifth aspect, it is possible to eliminate the adverse effect on the EGR control amount due to the intake pressure feedback control.
[0016]
(Invention of claim 7)
The control device for an internal combustion engine according to any one of claims 1 to 3,
When it is determined that the correction amount of the throttle amount is equal to or larger than the predetermined value C3 and that the amount of change in the intake pressure is smaller than the predetermined value C4, it is determined that the turbocharger is abnormal.
When the correction amount of the throttle amount is equal to or more than the predetermined value C3, that is, when the turbocharger is sufficiently throttled but the intake pressure does not change accordingly, the turbocharger is operating normally. Therefore, it is determined that the turbocharger is abnormal.
[0017]
(Invention of claim 8)
The control device for an internal combustion engine according to any one of claims 1 to 3,
If the correction amount of the throttle amount is determined to be equal to or greater than the predetermined value C3, the change amount of the intake pressure is determined to be equal to or greater than the predetermined value C4, and if the change amount of the EGR control amount is determined to be smaller than the predetermined value C5, the EGR It is determined that the control amount detecting means is abnormal.
When the correction amount of the throttle amount is equal to or more than the predetermined value C3 and the intake pressure changes accordingly (the amount of change is equal to or more than the predetermined value C4), it can be determined that the turbocharger is operating normally. Therefore, when the change amount of the EGR control amount is smaller than the predetermined value C5 even though the turbocharger is normal, the EGR control amount detecting means for detecting the EGR control amount is not operating normally. Therefore, it is determined that the EGR control amount detecting means is abnormal.
[0018]
(Invention of claim 9)
The control device for an internal combustion engine according to any one of claims 1 to 3,
If the correction amount of the throttle amount is determined to be equal to or greater than the predetermined value C3, the change amount of the intake pressure is determined to be equal to or greater than the predetermined value C4, and if the change amount of the EGR control amount is determined to be equal to or greater than the predetermined value C5, the EGR valve Is determined to be malfunctioning or abnormality of the valve opening detecting means for detecting the valve opening.
If the turbocharger operates normally and there is no abnormality in the EGR control amount detection means, the turbocharger is sufficiently throttled (a correction amount of the throttle amount is equal to or more than a predetermined value C3), thereby achieving the target EGR control. It is possible to achieve the quantity. Nevertheless, if the EGR control amount does not reach the target value, the EGR valve is not sufficiently opened, that is, the EGR valve is stuck and malfunctioning, or the valve opening for detecting the valve opening is detected. Since the abnormality of the detecting means is considered, it is determined that the operation of the EGR valve is defective or the valve opening detecting means is abnormal.
[0019]
(Invention of claim 10)
The control device for an internal combustion engine according to any one of claims 1 to 3,
A correction amount storage unit that stores a correction amount of the throttle amount, and when the operating condition of the internal combustion engine changes, the throttle amount is determined by the correction amount stored in the correction amount storage unit under the changed operating condition. It is characterized by correction.
In this method, the correction amount obtained under a certain operating condition is learned, and the learned value (correction amount) can be reflected on the throttle amount after the operating condition has changed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic control diagram showing a control system of an internal combustion engine.
First, the overall configuration of the control system will be described with reference to FIG.
This control system is applied to an internal combustion engine (called engine 1) that includes a variable capacity turbocharger (called VNT) and performs EGR that returns a part of exhaust gas to an intake system. (Referred to as ECU2).
[0021]
In the engine 1, as shown in FIG. 1, an injector 3 is attached to a cylinder head, and high-pressure fuel stored in a common rail (not shown) is injected from the injector 3 into a combustion chamber 1a.
The VNT includes an exhaust turbine 5 provided in an exhaust passage 4 of the engine 1 and a compressor 7 provided in an intake passage 6. The VNT opening (throttle amount) is controlled by the ECU 2 to control the supercharging pressure.
[0022]
In the EGR, an EGR valve 9 is provided in the middle of an EGR passage 8 that connects the exhaust passage 4 and the intake passage 6, and the amount of exhaust gas (EGR amount) recirculated to the intake side is adjusted according to the opening degree of the EGR valve 9. Is done.
The EGR passage 8 is connected to the exhaust passage 4 upstream of the exhaust turbine 5 and connected to the intake passage 6 downstream of the compressor 7.
The EGR valve 9 is, for example, a linear solenoid valve having a built-in solenoid, and varies the opening degree of the EGR passage 8 by lifting according to a valve lift command value output from the ECU 2. The EGR valve 9 is provided with a lift sensor (valve opening detecting means) for detecting a valve lift (EGR operation amount), and converts the detected valve lift into an electric signal and outputs it to the ECU 2.
[0023]
An air flow meter (referred to as an AFM 10) for measuring the amount of intake air is provided upstream of the compressor 7 in the intake passage 6, and an intake pressure sensor 11 for detecting the intake pressure in the intake passage 6 is provided downstream of the compressor 7. An intake throttle 12 is disposed downstream of the intake pressure sensor 11. An air cleaner (not shown) for filtering intake air is installed at the most upstream portion of the intake passage 6.
An A / F sensor 13 (O ₂ sensor) for detecting the concentration of exhaust O ₂ is attached to the exhaust passage 4 downstream of the exhaust turbine 5.
Information detected by the AFM 10, the intake pressure sensor 11, and the A / F sensor 13 is output to the ECU 2.
[0024]
The ECU 2 controls the VNT opening to change the supercharging pressure, and controls the opening of the EGR valve 9 to adjust the EGR amount, thereby realizing optimum exhaust gas characteristics for each operating condition of the engine 1. ing.
If the target EGR amount (EGR control amount) cannot be achieved even by controlling the EGR valve 9, a VNT opening correction control program and a failure determination program described below are executed. The processing procedure of the correction control and the failure determination program will be described based on the flowchart shown in FIG.
[0025]
First, a VNT opening correction control program is executed.
Step 100: EGR control amount and EGR operation amount are input. Here, the EGR control amount is a physical quantity influenced the EGR amount, or EGR amount (e.g., EGR rate, A / F, the fresh air amount, the exhaust _{O 2} concentration and the intake _{O 2} concentration), this embodiment In the following, a description will be given as an intake air amount (referred to as a fresh air amount) measured by the AFM 10.
The EGR operation amount is a lift amount of the EGR valve 9 or a drive current corresponding to the lift amount. In this embodiment, the EGR operation amount will be described as a valve lift amount (valve opening) detected by a lift amount sensor.
[0026]
Step 110: It is determined whether or not the lift amount (EGR operation amount) of the EGR valve 9 is equal to or greater than a predetermined value C1 corresponding to substantially full opening. When the determination result is YES (the valve lift amount is substantially maximum), the process proceeds to Step 120, and when the determination result is NO, the process proceeds to Step 130.
Step 120: It is determined whether a deviation ΔAFMt from the target value of the EGR control amount (fresh air amount) is equal to or larger than a predetermined value C2. That is, it is determined whether the fresh air amount is too large for the target value (whether the EGR amount is insufficient for the target value). When the determination result is YES (when the EGR amount is insufficient for the target value), the process proceeds to Step 140, and when the determination result is NO, the process proceeds to Step 130.
[0027]
Step 130: Reset the control counter i (i = 0) and return (return to Step 100).
Step 140: The counter i is updated (i = i + 1), and the process proceeds to Step 150.
Step 150: A correction amount ΔVNT (i) = K × ΔAFMt of the VNT opening is calculated in accordance with the deviation ΔAFMt obtained in the above Step 120 (K: coefficient).
[0028]
Step 160: The correction amount is learned. Here, ΔVNT is obtained by adding the correction amount ΔVNT (i) calculated every time until the condition of Step 110 or Step 120 is not satisfied (the determination result is NO). The learned correction amount ΔVNT is stored in the correction amount storage device 14 (see FIG. 1) built in the ECU 2.
Step 170: The VNT opening (VNT command opening or drive current) VNT (1) is corrected by the correction amount ΔVNT obtained in Step 160. Here, the VNT opening degree VNT (1) is a value preset for each operating condition in the case of the open control, and is controlled based on the target intake pressure in the case of the intake pressure F / B control. It is a value.
[0029]
Thereafter, the failure determination program is subsequently executed.
Step 180: The change amount Δpim of the intake pressure sensor 11 and the change amount ΔAFM of the AFM 10 are calculated.
Step 190: It is determined whether the correction amount ΔVNT obtained in Step 160 is smaller than a predetermined value C3. When the result of the determination is YES, the process returns to Step 100, and when the result of the determination is NO, the process proceeds to Step 200.
[0030]
Step 200: It is determined whether or not the variation Δpim of the intake pressure sensor 11 is smaller than a predetermined value C4. When the result of the determination is YES, the process proceeds to Step 210, and when the result of the determination is NO, the process proceeds to Step 220.
Step 210: It is determined that the VNT has failed. If the determination result in Step 200 is YES, although the correction amount ΔVNT of the VNT is equal to or more than the predetermined value C3 (the throttle is sufficiently squeezed), no change is observed in the intake pressure in response thereto. It is considered that it is not working. Therefore, the VNT is determined to be faulty, and the process ends.
[0031]
Step 220: It is determined whether the amount of change ΔAFM of the AFM 10 is smaller than a predetermined value C5. When the result of the determination is YES, the process proceeds to Step 230, and when the result of the determination is NO, the process proceeds to Step 240.
Step 230: It is determined that the AFM 10 has failed. If the determination result in Step 220 is YES, the intake pressure has changed due to the correction of the VNT opening, but the change in the fresh air amount has not been observed, so it is considered that the AFM 10 is not operating normally. Therefore, the AFM 10 is determined to have failed, and the process ends.
[0032]
Step 240: It is determined that the lift amount sensor has failed. If the determination result in Step 220 is NO, the VNT operates normally and there is no abnormality in the AFM 10 irrespective of the fact that the VNT correction amount ΔVNT is equal to or larger than the predetermined value C3 (it is sufficiently narrowed), By sufficiently narrowing the VNT (the correction amount ΔVNT is equal to or more than the predetermined value C3), the EGR amount increases and the target EGR control amount can be achieved. Nevertheless, if the target cannot be achieved, it can be determined that the output of the lift amount sensor is abnormal, that is, the lift amount sensor is out of order.
[0033]
(Effects of the present embodiment)
In the present control system, when it is difficult to achieve the target of the EGR control amount (for example, A / F) by the EGR valve 9, that is, when the EGR control amount cannot satisfy the target value even though the EGR valve 9 is almost fully opened. In addition, the target EGR control amount is secured by correcting the VNT opening. That is, when the VNT opening is reduced (the throttle amount is increased), the exhaust pressure in the exhaust passage 4 (upstream from the exhaust turbine 5) increases accordingly, so that the EGR amount increases and the target EGR control amount decreases. Can be secured.
[0034]
(Modification)
In the above embodiment, the correction amount ΔVNT (i) of the VNT opening is obtained according to the deviation ΔAFMt from the target value of the EGR control amount (fresh air amount). However, the correction amount may be a constant value.
The correction amount ΔVNT obtained in Step 160 is stored in the correction amount storage device 14 (see FIG. 1) built in the ECU 2, and when the operating condition changes, the VNT is calculated based on the correction amount stored in the correction amount storage device 14. The opening may be corrected. In this case, even when the EGR valve 9 is controllable, the amount of variation in the VNT opening can be reduced, so that the convergence of the control amounts of the EGR and VNT to the target values can be improved. Even if the correction control program is not executed, the target EGR control amount can be secured.
[0035]
In the above-described embodiment, the example in which the VNT opening is corrected when it is difficult to achieve the target of the EGR control amount by the EGR valve 9 has been described. However, when the intake pressure F / B control is performed on the VNT, the VNT is corrected. The intake pressure F / B control may be stopped without correcting the opening. Alternatively, the F / B amount may be reset to a preset throttle amount for each operating condition. In this case, an adverse effect on the EGR control amount due to the intake pressure F / B control can be eliminated.
Further, when the intake pressure F / B control of the VNT is performed, and it is difficult to achieve the target of the EGR control amount by the EGR valve 9, even if the intake pressure F / B control is stopped and the VNT opening is corrected. good.
[0036]
In the above embodiment, the valve lift amount detected by the lift amount sensor is described as the EGR operation amount. However, when the drive current for driving the EGR valve 9 is the EGR operation amount, the flowchart shown in FIG. In step 240, it can be determined that the EGR valve 9 is malfunctioning. That is, if the VNT operates normally and there is no abnormality in the AFM 10, the target EGR control amount can be achieved by sufficiently narrowing the VNT (the correction amount is equal to or more than the predetermined value C3). Nevertheless, if the EGR amount does not increase, it is considered that the EGR valve 9 is stuck and the operation is defective. Therefore, it is determined that the EGR valve 9 is defective (abnormal).
[Brief description of the drawings]
FIG. 1 is a control schematic diagram schematically showing the present control system.
FIG. 2 is a flowchart showing a processing procedure of a VNT opening correction control program and a failure determination program.
FIG. 3 is a characteristic diagram showing a relationship between an intake pressure and a VNT opening (throttle amount).
FIG. 4 is a characteristic diagram showing a relationship between an EGR control amount (A / F) and an EGR valve opening.
[Explanation of symbols]
1 engine (internal combustion engine)
2 ECU (control device)
5 Exhaust turbine (variable capacity turbocharger)
7 Compressor (variable capacity turbocharger)
8 EGR passage 9 EGR valve 10 AFM (air flow meter)
11 intake pressure sensor 14 correction amount storage device (correction amount storage means)

Claims (10)

A control device for an internal combustion engine that has a variable capacity turbocharger that varies the throttle amount, controls the throttle amount of the turbocharger, and controls the EGR valve opening that returns a part of the exhaust gas to the intake system. So,
EGR control amount detection means for detecting the EGR control amount (eg, EGR amount, fresh air amount, etc.);
First determining means for determining whether or not the operation amount of the EGR valve (valve opening or a drive current corresponding to the valve opening) is equal to or greater than a predetermined value C1;
A second determination unit that determines whether a deviation of the EGR control amount from the target value detected by the EGR control amount detection unit is equal to or greater than a predetermined value C2,
A direction in which the exhaust pressure of the turbocharger increases when it is determined that the operation amount of the EGR valve is equal to or more than a predetermined value C1 and the deviation of the EGR control amount from a target value is equal to or more than a predetermined value C2. A control device for the internal combustion engine, wherein the throttle amount is corrected. Equipped with a variable-capacity turbocharger that varies the throttle amount, feedback-controls the throttle amount of this turbocharger based on the target intake pressure, and controls the EGR valve opening that returns a part of the exhaust gas to the intake system. A control device for an internal combustion engine,
EGR control amount detection means for detecting the EGR control amount (eg, EGR amount, fresh air amount, etc.);
First determining means for determining whether or not the operation amount of the EGR valve (valve opening or a drive current corresponding to the valve opening) is equal to or greater than a predetermined value C1;
A second determination unit that determines whether a deviation of the EGR control amount from the target value detected by the EGR control amount detection unit is equal to or greater than a predetermined value C2,
When it is determined that the operation amount of the EGR valve is equal to or more than a predetermined value C1 and the deviation of the EGR control amount from a target value is equal to or more than a predetermined value C2, the feedback control of the turbocharger is stopped and A controller for correcting the throttle amount in a direction in which the exhaust pressure of the turbocharger increases. The control device for an internal combustion engine according to claim 1 or 2,
A control device for an internal combustion engine, wherein when correcting the throttle amount, the correction amount is calculated according to a deviation of the EGR control amount from a target value. The control device for an internal combustion engine according to claim 1 or 2,
A control device for an internal combustion engine, wherein, when correcting the throttle amount, the correction amount is set to a predetermined constant value. Equipped with a variable-capacity turbocharger that varies the throttle amount, feedback-controls the throttle amount of this turbocharger based on the target intake pressure, and controls the EGR valve opening that returns a part of the exhaust gas to the intake system. A control device for an internal combustion engine,
EGR control amount detection means for detecting the EGR control amount (eg, EGR amount, fresh air amount, etc.);
First determining means for determining whether or not the operation amount of the EGR valve (valve opening or a drive current corresponding to the valve opening) is equal to or greater than a predetermined value C1;
A second determination unit that determines whether a deviation of the EGR control amount from the target value detected by the EGR control amount detection unit is equal to or greater than a predetermined value C2,
Stopping the feedback control of the turbocharger when it is determined that the operation amount of the EGR valve is equal to or more than a predetermined value C1 and the deviation of the EGR control amount from a target value is equal to or more than a predetermined value C2. A control device for an internal combustion engine, comprising: The control device for an internal combustion engine according to claim 5,
In advance, throttle amount control data that is a predetermined throttle amount of the turbocharger corresponding to each operating condition is stored, and when feedback control of the turbocharger is stopped, control immediately after the stop is performed. A control device for an internal combustion engine, wherein data is held or open control is performed by applying the throttle control data. The control device for an internal combustion engine according to any one of claims 1 to 3,
Correction amount determining means for determining whether or not the correction amount of the aperture amount is equal to or greater than a predetermined value C3;
Intake pressure change amount determination means for determining whether the change amount of the intake pressure is equal to or more than a predetermined value C4,
When the correction amount of the throttle amount is determined to be equal to or more than a predetermined value C3 and the change amount of the intake pressure is determined to be smaller than a predetermined value C4, it is determined that the turbocharger is abnormal. Control device for internal combustion engine. The control device for an internal combustion engine according to any one of claims 1 to 3,
Correction amount determining means for determining whether or not the correction amount of the aperture amount is equal to or greater than a predetermined value C3;
Intake pressure change amount determining means for determining whether the change amount of the intake pressure is equal to or less than a predetermined value C4;
EGR change amount determination means for determining whether the change amount of the EGR control amount detected by the EGR control amount detection means is equal to or greater than a predetermined value C5,
When the correction amount of the throttle amount is determined to be equal to or more than a predetermined value C3, the change amount of the intake pressure is determined to be equal to or more than a predetermined value C4, and the change amount of the EGR control amount is determined to be smaller than a predetermined value C5. A control device for the internal combustion engine, which determines that the EGR control amount detecting means is abnormal. The control device for an internal combustion engine according to any one of claims 1 to 3,
Correction amount determining means for determining whether or not the correction amount of the aperture amount is equal to or greater than a predetermined value C3;
Intake pressure change amount determining means for determining whether the change amount of the intake pressure is equal to or less than a predetermined value C4;
EGR change amount determination means for determining whether the change amount of the EGR control amount detected by the EGR control amount detection means is equal to or greater than a predetermined value C5,
When the correction amount of the throttle amount is determined to be equal to or more than a predetermined value C3, the change amount of the intake pressure is determined to be equal to or more than a predetermined value C4, and when the change amount of the EGR control amount is determined to be equal to or more than a predetermined value C5. A control device for the internal combustion engine, which determines that the operation of the EGR valve is defective or the valve opening detecting means for detecting the valve opening is abnormal. The control device for an internal combustion engine according to any one of claims 1 to 3,
A correction amount storage unit that stores a correction amount of the aperture amount,
A control device for an internal combustion engine, wherein when the operating condition of the internal combustion engine changes, the throttle amount is corrected by the correction amount stored in the correction amount storage means under the changed operating condition.

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