JP2002038982A - Operation controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve controllability for supercharged pressure and the EGR amount. SOLUTION: An ECU controls an EGR valve on the basis of the operating state of an engine main body, detected on the basis of the engine speed NE and the accelerator opening ACCP. The oxygen concentration DO to be changed according to the EGR amount is feedback-controlled so as to eliminate the deviation to the target oxygen concentration DOd in relation to the operating state. When the EGR amount is not zero, the ECU makes the nozzle vane opening of a supercharger the opening preset in relation to the operating state and controls supercharged pressure PI.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for an internal combustion engine that performs both EGR control and supercharging pressure control using a variable capacity turbocharger.

[0002]

2. Description of the Related Art Conventionally, for example, a diesel engine for a vehicle has been equipped with an EGR to reduce NOx in exhaust gas.
(Exhaust gas recirculation) equipment is employed. This EGR
In the device, an electronic control unit (hereinafter, referred to as an ECU) controls an EGR valve based on an operation state of the engine to control an EGR amount according to the operation state at that time, thereby preventing generation of particulate emissions. While reducing NOx as much as possible.

[0003] The ECU controls the EGR amount to a target EGR amount optimal for the operating state at that time based on, for example, the engine speed and the accelerator opening. The ECU obtains an optimal target oxygen concentration for the operating state at that time from the engine speed and the accelerator opening, and adjusts the EGR valve so as to eliminate the deviation between the target oxygen concentration and the actual oxygen concentration.
The GR amount is feedback-controlled to the target EGR amount. The EGR amount is set to “0”, for example, in order to ensure drivability when the engine is cold and to prevent the emission of black smoke during high load operation.

On the other hand, in order to obtain higher torque in a wider engine operating range without deteriorating exhaust emission and to further improve fuel efficiency, many diesel engines are supercharged by a turbocharger. It is carried out. Furthermore, a variable displacement turbocharger (variable nozzle vane type) with variable turbine capacity (amount of intake air that can be supercharged with respect to exhaust pressure) in order to obtain higher torque in a wider operating range
Has been adopted. In the variable capacity supercharger, the variable nozzle vanes are controlled by the ECU based on the operation state of the engine, and the turbine capacity is optimally controlled according to the operation state at that time.

[0005] For example, the ECU obtains a target supercharging pressure from the engine speed and the accelerator opening and detects an actual supercharging pressure which is an actual supercharging pressure. The supercharging pressure is feedback-controlled by adjusting the variable nozzle so as to eliminate the deviation.

However, when performing the EGR control and the variable supercharging control together, if the EGR amount is increased by the EGR control, the exhaust pressure decreases, and the supercharging pressure controlled by the supercharging pressure control changes. . Further, when the turbine capacity is changed by the supercharging pressure control, the differential pressure across the EGR valve changes, and the EGR amount changes. That is, since the EGR control and the supercharging pressure control affect each other's control, it is not easy to control the EGR rate and the supercharging pressure to the respective target values.

To solve such a problem, Japanese Patent Laid-Open No.
A control device for an engine with a turbocharger disclosed in 00-73776 has been proposed. This control device detects the differential pressure across the EGR valve, and controls the turbine speed to change more slowly as the differential pressure increases. Therefore, in an operation state in which the EGR amount largely changes even if the differential pressure between the front and rear is large and the valve opening degree of the EGR valve is slightly changed, the speed of change of the turbine capacity is slow. It becomes difficult to receive and is quickly controlled to the target opening. Conversely, the differential pressure between the front and rear is small and E
In an operation state in which the EGR amount does not change so much even if the valve opening of the GR valve is significantly changed, the fuel consumption of the engine is sufficiently improved because the change speed of the turbine capacity is high. Therefore, while preventing the increase of particulate matter, the N
The OX amount can be reduced, and higher torque or better fuel economy can be obtained in a wider operating range.

[0008]

However, the EGR control and the supercharging pressure control, which affect each other's control,
It is still not easy to perform each of them by feedback control, and it has been particularly difficult to keep the EGR rate at the target value.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to improve torque or fuel efficiency by a turbo-charger having an adjustable turbine capacity.
Provided is an operation control device for an internal combustion engine that can reduce NOx and prevent particulate emissions by an EGR device, and can further improve the controllability of supercharging pressure and exhaust gas recirculation amount. It is in.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to an exhaust gas recirculated from an exhaust passage of an internal combustion engine to an intake passage through an exhaust gas recirculation passage. Exhaust gas recirculation amount adjusting means for adjusting the gas recirculation amount, a variable capacity turbocharger capable of adjusting the turbine capacity according to the nozzle vane opening, and adjusting the turbine capacity by adjusting the nozzle vane opening. A turbine capacity adjusting means for adjusting a supercharging pressure supplied to the intake-side flow path by the variable-capacity turbocharger; and the exhaust gas recirculation amount, or control changing in response to the exhaust gas recirculation amount. An exhaust gas recirculation amount detecting means for detecting a state quantity; and a deviation between a target value of the exhaust gas recirculation amount with respect to an operation state of the internal combustion engine and a detection value thereof, or Exhaust gas return Feedback control means for performing feedback control via the exhaust gas recirculation amount adjusting means so as to eliminate a deviation between a target value of the control state amount corresponding to the target value of the amount and a detected value thereof; and When it is not controlled to “0”, the supercharging pressure control that controls the supercharging pressure via the turbine capacity adjusting means by setting the nozzle vane opening to a predetermined opening for the operating state. And the means.

According to this configuration, when the exhaust gas recirculation amount is not controlled to at least "0", the nozzle vane opening of the variable displacement turbocharger is set to a predetermined opening in accordance with the operation state. Thus, the supercharging pressure is controlled. For this reason, when the exhaust gas recirculation amount is adjusted based on the changed operating state, the supercharging pressure is controlled without being affected by the supercharging pressure changed by the change in the exhaust gas recirculation amount. Therefore, since the control of the supercharging pressure is not affected by the control of the exhaust gas recirculation amount, each controllability of the supercharging pressure and the exhaust gas recirculation amount is compared with the case where the supercharging pressure is also feedback-controlled. Better.

According to a second aspect of the present invention, in the first aspect of the present invention, the supercharger issues a command to the turbine capacity adjusting means for adjusting the turbine capacity for each individual turbocharger. A correction value for correcting the actual turbine capacity value with respect to the capacity command value to a preset reference capacity value is set in advance, and the supercharging pressure control unit corrects the capacity command value with the correction value. The gist is to control the turbine capacity adjusting means using the corrected capacity command value.

According to this structure, in addition to the operation of the invention described in claim 1, even if there is a difference in the actual turbine capacity value with respect to the capacity command value for each turbocharger, The capacity is controlled to a target value for the operating state. Therefore, there is no difference between individuals in the supercharging pressure controlled based on the operating state. As a result, the supercharging pressure can be appropriately controlled based on the operating state even if there is a difference in the turbine capacity characteristics of the turbocharger between the individual turbochargers.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is embodied in a vehicle diesel engine system will be described with reference to FIGS.
It will be described according to.

As shown in FIG. 1, a diesel engine system 10 includes an engine body 11 as an internal combustion engine, an electronically controlled fuel injection pump (hereinafter, referred to as a fuel injection pump) 12, and a turbocharger (hereinafter, supercharged). Machine.)
13, an EGR device 14, and an electronic control unit (hereinafter referred to as an ECU).
That. ) 15 and the like.

The engine body 11 includes a cylinder block having a plurality of cylinder ports and a water cooling jacket, a direct injection type cylinder head, and an OHC.
It has a valve train consisting of a mechanism. The cylinder head is provided with a fuel injection nozzle 16 for each cylinder port. A water temperature sensor 17 and a crank angle sensor 18 are provided in the cylinder block. In addition, a vacuum pump 19 driven by engine power is provided in the engine body.

The intake port of the engine body 11 is connected to an intake pipe 20 as an intake-side flow path via an intake manifold, and an air cleaner 21 is provided upstream of the intake pipe 20. An intake pressure sensor 22 and an intake temperature sensor 23 are provided on the intake pipe 20. On the other hand, the exhaust port is connected to an exhaust pipe 24 as an exhaust-side flow path via an exhaust manifold, and a muffler (not shown) is provided downstream of the exhaust pipe 24. An oxygen sensor 25 is provided on the exhaust pipe 24 as exhaust gas recirculation amount detecting means.

The fuel injection pump 12 includes a feed pump and a plunger pump (not shown) and an electromagnetic spill valve 2.
6 and a timing control valve 27. The feed pump is driven by engine power and pumps fuel supplied from a fuel tank by a primary pump (not shown) to a plunger pump. The electromagnetic spill valve 26 receives an external electric signal S
Open / close control by 1 stops or permits charging of fuel from the feed pump to the plunger pump. The plunger pump is driven by engine power, pressurizes the fuel pumped from the feed pump, and pumps the fuel to the delivery valve. The timing control valve 27 is an electromagnetic control valve, which is driven by an external electric signal S2, and controls the timing at which the plunger pump starts pumping fuel. Therefore, the fuel injection pump 12 supplies fuel to each fuel injection nozzle 16 at the fuel injection start timing and the injection end timing commanded by the external electric signals S1 and S2 for controlling the electromagnetic spill valve 26 and the timing control valve 27. The fuel is fed to control the fuel injection timing and fuel injection amount for each combustion chamber. The fuel injection pump 12 is provided with an engine speed sensor 28.

The EGR device 14 includes an electromagnetic negative pressure control valve (hereinafter, referred to as E-VRV) 29 and an exhaust gas recirculation control valve (hereinafter, referred to as EGR valve) 30. E
The -VRV 29 is activated by the external electric signal S3, and continuously adjusts the negative pressure supplied from the vacuum pump 19 to supply the negative pressure to the EGR valve 30. The EGR valve 30
The valve opening is adjusted according to the magnitude of the negative pressure supplied from -VRV29. The EGR valve 30 adjusts the cross-sectional area of the exhaust gas recirculation path 31 that connects the exhaust pipe 24 and the intake pipe 20 according to the valve opening. EGR valve 3
In the case of 0, the valve opening degree increases as the negative pressure increases, and the cross-sectional area of the flow path is adjusted to be larger. When there is no negative pressure, the valve is closed to set the cross-sectional area of the flow path to “0”. In the present embodiment, E
The VRV 29 and the EGR valve 30 constitute an exhaust gas recirculation amount adjusting means.

An intake pipe 20 and an exhaust pipe 24 are connected to the supercharger 13, respectively. Specifically, the turbocharger 1
3, the intake pipe 20 is provided with an intake pressure sensor 2
2, and an exhaust pipe 24 is connected to the turbine side on the upstream side of the oxygen sensor 25. A known variable nozzle vane mechanism 32 is provided on the turbine side of the supercharger 13. The nozzle vane opening of the variable nozzle vane mechanism 32 is adjusted by an actuator 33 serving as a turbine capacity adjusting means operated by an external electric signal S4.
The turbine capacity TC is adjusted according to the nozzle vane opening. The actuator 33 uses, for example, a stepping motor as a drive source, and continuously adjusts the nozzle vane opening based on the opening command value S of the external electric signal S4. Therefore,
The supercharger 13 performs supercharging with the turbine capacity TC commanded by the external electric signal S4 for controlling the actuator 33.

The supercharger 13 is provided with a correction resistor 34 having a resistance value RG set in advance for each individual. This correction resistor 34 is provided for each individual turbocharger 13.
It is used to correct the variation of the turbine capacity TC with respect to the opening command value S.

An accelerator pedal 3 provided in the vehicle
5, an accelerator opening sensor 36 is provided. Next, the electrical configuration of the engine operation control device configured as described above will be described with reference to the electrical block diagram of FIG.

The water temperature sensor 17 detects the water temperature THW of the cooling water, and outputs a detection signal of a magnitude corresponding to the detected value to the ECU.
15 is output. The crank angle sensor 18 generates a pulse once when the crank angle reaches a preset reference crank angle CA per one rotation of the crankshaft, and outputs this pulse crank signal to the ECU 15. The intake pressure sensor 22 detects a supercharging pressure (intake pressure) PI and outputs a detection signal of a magnitude corresponding to the detected value to the ECU 15.
The intake air temperature sensor 23 detects the intake air temperature THA and outputs a detection signal of a magnitude corresponding to the detected value to the ECU 15.
The oxygen sensor 25 detects the oxygen concentration DO in the exhaust gas as a control state quantity, and outputs a detection signal of a magnitude corresponding to the detected value to the ECU 15. Engine speed sensor 2
8 outputs to the ECU 15 a pulse rotation speed signal having a cycle corresponding to the engine rotation speed NE. Accelerator opening sensor 36
Detects the accelerator opening ACCP and outputs a detection signal of a magnitude corresponding to the detected value to the ECU 15. In the present embodiment, the accelerator opening ACCP and the engine speed N
From E, the operating state of the engine body 11 is detected.

The ECU 15 as the supercharging pressure control means and the feedback control means includes a microcomputer 40,
A drive circuit 41 and the like are provided. Then, the microcomputer 40 executes the control program stored in advance to control the operation of the engine body 11.

The ECU 15 performs the operation control as follows: the water temperature THW, the reference crank angle CA, and the supercharging pressure P output from each sensor.
I, intake air temperature THA, oxygen concentration DO, engine speed NE
Based on the accelerator opening ACCP and well-known fuel injection amount control, fuel injection timing control, EGR control, supercharging pressure control, and the like.

As the fuel injection amount control, the ECU 15 detects the engine speed NE from the pulse speed signal, and determines the basic target injection amount of the fuel from the engine speed NE and the accelerator opening ACCP. Further, a final target injection amount is determined by correcting the basic target injection amount based on the supercharging pressure PI, the intake air temperature THA, and the water temperature THW. And EC
U15 controls the opening and closing of the electromagnetic spill valve 26 via the driving device 37, and controls the fuel injection amount to the final target injection amount by adjusting the fuel injection end timing.

As the fuel injection timing control, the ECU 15
The basic target injection timing of the fuel is determined from the accelerator opening ACCP and the engine speed NE. Further, a final target injection timing is determined by correcting the basic target injection timing based on the supercharging pressure PI and the water temperature THW. And the ECU 15
Determines the crank angle from the reference crank angle CA and the engine speed NE, and controls the fuel injection timing to the final target injection timing by adjusting the duty of the timing control valve 27 to adjust the fuel injection start timing.

In the EGR control, the ECU 15 matches the target EGR amount set according to the operating state of the engine main body 11 when there is no possibility that a problem will occur due to the EGR operation state of the engine main body 11. Thus, the actual EGR amount is feedback-controlled. ECU1
No. 5 performs this EGR control by executing the EGR control processing shown in the flowchart of FIG. The EGR control process is repeatedly executed by, for example, an interrupt process based on a pulse crank angle signal.

In FIG. 6, the ECU 15 firstly proceeds to step (hereinafter abbreviated as S) 20 at an accelerator opening AC.
CP, engine speed NE, water temperature THW, and oxygen concentration D
Read O. Next, in S21, it is determined whether or not the water temperature THW exceeds a predetermined reference water temperature THWS.

The reference water temperature THWS is determined based on the engine body 1
EGR due to the low coolant temperature THW of the first cooling water
Is set in order to determine whether or not the drivability is not impaired when the operation is performed. Therefore, EC
U15 determines whether or not the coolant temperature THW of the cooling water of the engine body 11 is in a state in which EGR may be performed by executing S21.

When the water temperature THW is equal to or lower than the reference water temperature THWS in S21 and the drivability is impaired, in S22, E
An external electric signal S3 for closing the GR valve 30 fully is set to E
-Apply to VRV 29. Then, in the next S23, EG
The process is terminated with the R flag FEGR set to “0”.

On the other hand, at S21, the water temperature THW is changed to the reference water temperature T.
If HWS is exceeded and drivability is not impaired, S
24, the accelerator opening ACCP and the engine speed NE
Then, a target torque Tsol is obtained using a map (not shown). Then, in S25, it is determined whether or not the target torque Tsol is less than a preset reference torque Tstd.

The reference torque Tstd is determined by EG due to the high load torque of the engine body 11.
This is set in order to determine whether or not the particulate emissions in the exhaust emissions increase to a certain value or more when R is performed. Therefore, the ECU 15 determines that S2
By executing step 5, it is determined whether or not the load torque of the engine body 11 is in a state in which EGR may be performed.

When the target torque Tsol is equal to or larger than the reference torque Tstd in S25 and the particulate matter in the exhaust emission increases beyond a certain limit, the flow goes to S2.
2 and S23 are executed, and this processing ends.

On the other hand, when the target torque Tsol is smaller than the reference torque Tstd and the particulate emission does not increase beyond a certain limit in S25, the EGR flag F is set in S26.
After setting the EGR to “1”, S27 is executed.

In step S27, the target fuel injection amount QF is calculated from the engine speed NE and the accelerator opening ACCP using a map.
Find IN. Next, in S28, a target oxygen concentration DOd is determined from the engine speed NE and the target fuel injection amount QFIN using a map.

Subsequently, in S29, E-VRV is set so as to eliminate the deviation between the target oxygen concentration DOd and the actual oxygen concentration DO.
The EGR amount is controlled by controlling the EGR valve 30 by adjusting 29 and controlling the oxygen concentration DO.

Accordingly, in the EGR control process, when the EGR control does not hinder the operation state of the engine body 11, the target oxygen concentration DOd
And the EGR amount is feedback-controlled so as to eliminate the deviation between the target EGR amount corresponding to the actual EGR amount and the EGR amount corresponding to the actual oxygen concentration DO.

Further, as the supercharging pressure control, the ECU 15
Controls the supercharging pressure PI according to the operating state of the engine body 11. The ECU 15 performs this supercharging pressure control by executing a supercharging pressure pre-process shown in the flowchart of FIG. 5 and a supercharging pressure control process shown in the flowchart of FIG.

The supercharging pressure pre-processing is executed only once, for example, when the ECU 15 is started, and the supercharging pressure control processing is executed by interruption every predetermined time, for example. In FIG. 5, the ECU
15 reads the resistance value RG of the correction resistor 34 in S10. Then, in S11, a correction value ΔS for the opening command value S as a capacity command value to be commanded to the actuator 33 by the external electric signal S4 is obtained from the resistance value RG using a predetermined relational expression.

The reason for obtaining the correction value ΔS of the opening command value S of the actuator 33 in the pre-charging pressure process will be described. The turbine capacity characteristic of the supercharger 13 is shown as a change characteristic of the turbine capacity TC with respect to the opening command value S, as shown in FIG. Since the turbine capacity characteristics vary from one turbocharger 13 to another, the turbine capacity characteristics vary within a range between a lower limit characteristic and an upper limit characteristic indicated by a broken line in FIG. 3, for example. Therefore, when the ECU 15 attempts to adjust the turbine capacity TC, the value of the turbine capacity TC with respect to the same opening command value S differs for each turbocharger 13, and the turbine of each turbocharger 13 The capacity TC cannot be adjusted in the same way. Therefore, the opening command value S is corrected for each supercharger 13 such that the turbine capacity TC for the same opening command value S becomes the same value in each supercharger 13.

In this method, first, a predetermined reference command value SA is set for the opening command value S, and the nominal value of the turbine capacity TC with respect to the reference command value SA is set to the reference capacity value T.
Set as CA. In the present embodiment, the reference capacity value TCA is a median value of a range of variation of the turbine capacity TC taken by each turbocharger 13 with respect to the reference command value SA. Then, the reference capacity value T is compared with the reference command value SA.
A turbine capacity characteristic taking CA is defined as a reference capacity characteristic A,
The turbine capacity characteristic of each turbocharger 13 is corrected to the reference capacity characteristic A.

As shown in FIG. 4, for example, a turbine capacity characteristic B indicated by a two-dot chain line where the value of the turbine capacity TC with respect to the reference command value SA is smaller than the reference capacity value TCA.
For the supercharger 13, the deviation (SB-SA) between the actual opening command value SB and the reference command value SA when the turbine capacity TC reaches the reference capacity value TCA is corrected by ΔS = ΔS
B (= SB−SA) is set for the supercharger 13. Accordingly, when the ECU 15 controls the turbine capacity TC of the turbocharger 13 having the turbine capacity characteristic B, the opening command value S for the target turbine capacity TC is controlled.
Is corrected by the correction value ΔS = ΔSB, thereby controlling the turbine capacity TC in the same manner as the supercharger 13 having the reference capacity characteristic A.

Similarly, for the turbocharger 13 having a turbine capacity characteristic C indicated by a two-dot chain line in which the value of the turbine capacity TC with respect to the reference command value SA is larger than the reference capacity value TCA, the turbine capacity TC is equal to the reference capacity. Deviation between the actual opening command value SC and the reference command value SA when the value TCA is reached (SC−
SA) is set for the supercharger 13 as the correction value ΔS = ΔSC (= SC−SA). Accordingly, when the ECU 15 controls the turbine capacity TC of the turbocharger 13 having the turbine capacity characteristic C, the opening command value S for the target turbine capacity TC is corrected by the correction value ΔS = ΔSC. As a result, the turbocharger 1 having the reference capacity characteristic A
3, the turbine capacity TC is controlled.

In practice, it is difficult to prepare a correction resistor 34 having a different resistance value RG corresponding to the correction value ΔS for each turbocharger 13. Variation range T of value of capacitance TC
CW, that is, the range between the lower limit characteristic turbine capacity value TCL and the upper limit characteristic turbine capacity value TCU with respect to the reference command value SA is divided into an appropriate number of small ranges. Then, the turbine capacity TC with respect to the reference command value SA
Of the turbocharger 13 in which the values of the correction values .DELTA.S take a value in each of the divided small ranges, the correction values .DELTA.S are regarded as the same value, and the correction resistors 34 having the same resistance value RG are attached. I do.

In FIG. 7, the ECU 15 first determines in step S40 that the accelerator opening ACCP and the engine speed N
E and the supercharging pressure PI are read. Next, in S41, a target torque Tsol is obtained from the read accelerator opening ACCP and engine speed NE using a map. further,
In S42, the target torque Tsol and the engine speed N
From E, a target supercharging pressure PIsol is obtained using a map.

Subsequently, at S43, the EGR flag EFR
It is determined whether or not G is “1”. When the EGR flag EFRG is "1" in S43, the opening command value S corresponding to the target supercharging pressure PIsol and the correction value ΔS are added in S44, and the correction opening command as a correction capacity command value is added. Find the value SR (= S + ΔS). Next, in S45, the actuator 33 is controlled with the corrected opening command value SR,
The turbine capacity TC is controlled by adjusting the nozzle vane opening.

That is, the ECU 15 determines that the EGR amount is "0".
Is not controlled based on the target supercharging pressure PIsol set according to the operating state of the engine body 11, the supercharging pressure PI is not feedback-controlled, and the target supercharging pressure PI
By adjusting the nozzle vane opening to an opening preset for sol, the turbine capacity TC is adjusted and the supercharging pressure PI is controlled.

On the other hand, when the EGR flag FEGR is "0" at S43, at S46 the actual supercharging pressure PI
Read. Then, in S47, the turbine pressure TC is adjusted so as to eliminate the deviation between the supercharging pressure PI and the target supercharging pressure PIsol, and the supercharging pressure PI is feedback-controlled.

That is, the ECU 15 determines that the EGR amount is "0".
Is controlled to the target boost pressure PIsol that is set according to the operating state of the engine body 11.
Feedback control.

According to the above-described embodiment, the following effects can be obtained. (1) In the present embodiment, the EGR valve 30 is adjusted based on the operating state of the engine body 11 detected from the engine speed NE and the accelerator opening ACCP, and the oxygen concentration DO that changes in accordance with the EGR amount is controlled. Feedback control was performed so as to eliminate the deviation from the target oxygen concentration DOd with respect to the state. On the other hand, when the EGR amount is not set to “0”, the supercharging pressure PI is controlled by setting the nozzle vane opening degree set in advance according to the operating state without performing feedback control of the actual supercharging pressure PI. did.

For this reason, the supercharging pressure PI depends on the engine body 1
Since the control is performed based only on the operating state of No. 1, when the oxygen concentration DO, that is, the exhaust gas recirculation amount is adjusted based on the changed operation state, the influence of the supercharging pressure PI changed by the change in the exhaust gas recirculation amount. It is controlled without receiving. Therefore, since the control of the supercharging pressure PI is not affected by the control of the exhaust gas recirculation amount, each of the supercharging pressure PI and the exhaust gas recirculation amount is compared with a case where the supercharging pressure PI is also controlled by feedback. Controllability can be further improved. As a result, it is possible to improve torque or fuel efficiency by the turbocharger whose turbine capacity TC is adjustable, and to reduce NOx by the EGR device while preventing generation of particulate emissions. Each controllability of the EGR amount can be further improved.

(2) In this embodiment, the supercharger 1
3, a correction value Δ for correcting the actual turbine capacity TC with respect to the opening command value S to the reference capacity value TCA.
A correction resistor having a resistance value RG corresponding to S is provided. Then, the ECU 15 calculates a correction value Δ from the resistance value RG.
S is obtained, and the supercharger 1 is controlled using the corrected opening command value SR obtained by correcting the opening command value S with the correction value ΔS when controlling the supercharging pressure PI.
3 was controlled.

Therefore, even if there is a difference in the actual value of the turbine capacity TC with respect to the opening command value S for each individual turbocharger 13, the turbine capacity TC is controlled to the target value for the operating state. Accordingly, there is no difference between the individuals in the supercharging pressure PI controlled based on the operating state. As a result, the supercharging pressure PI can be appropriately controlled based on the operating state even if the turbine capacity characteristics of the supercharger 13 differ between the individual units.

Hereinafter, embodiments other than the above embodiments will be described. In the above embodiment, the first control state amount that changes in accordance with the EGR amount is the oxygen concentration DO in the exhaust gas.
This may be an intake air amount detected by an airflow sensor provided on the intake pipe 20 upstream of the supercharger 13.

In the above embodiment, instead of the supercharging pressure PI, the intake air amount as the second control state amount that changes in response to the supercharging pressure PI may be controlled based on the operating state. In the above embodiment, the actuator 33 may be a negative pressure actuator that operates by a negative pressure adjusted by the electromagnetic control valve.

In the above embodiment, the method of supplying fuel to the diesel engine is not limited to the distribution type fuel injection pump type, but may be a common rail type. In the above embodiment, the combustion system of the diesel engine is not limited to the direct injection system, but may be a sub-combustion chamber system (pre-combustion chamber system, vortex chamber system).

In the above embodiment, the operation mode of the diesel engine may be either four-cycle or two-cycle. Hereinafter, technical ideas grasped from each of the above-described embodiments will be described together with their effects.

(1) The operation control device for an internal combustion engine according to claim 2, wherein the correction value is set as a resistance value of a correction resistor provided for each individual turbocharger. Operation control device for an internal combustion engine. According to such a configuration, a correction value can be easily set for each supercharger.

[0060]

According to the first or second aspect of the present invention, the torque or fuel efficiency is improved by the turbocharger having an adjustable turbine capacity, the NOX is reduced by the EGR device, and the particulate emission is reduced. Can be prevented, and the controllability of the supercharging pressure and the exhaust gas recirculation amount can be further improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an engine system including an operation control device.

FIG. 2 is an electric block diagram of the operation control device.

FIG. 3 is a characteristic graph of a turbine capacity-opening command value.

FIG. 4 is a graph illustrating a correction value of an opening command value.

FIG. 5 is a flowchart of supercharging pressure pre-processing.

FIG. 6 is a flowchart of an EGR control process.

FIG. 7 is a flowchart of a supercharging pressure control process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Engine main body as an internal combustion engine, 13 ... Variable capacity turbocharger, 15 ... Electronic control device as supercharging pressure control means and feedback control means, 20 ... Intake pipe as intake side flow path, 24 ... Exhaust Exhaust pipe as side flow path, 2
5. Oxygen sensor as exhaust gas recirculation amount detecting means, 29
... electromagnetic negative pressure control valve constituting exhaust gas recirculation amount control means,
Numeral 30: Exhaust gas recirculation control valve, 33: Actuator as turbine capacity adjusting means, ACCP: Accelerator opening constituting operating state, DO: Oxygen concentration as control state quantity, NE: Engine speed, PI: Supercharging Pressure, S: Opening command value as capacity command value, SR: Corrected opening command value as corrected capacity command value, TC: Turbine capacity, TCA ...
Reference capacitance value, ΔS: correction value.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02B 37/12 302 F02D 23/00 J F02D 23/00 43/00 301N 43/00 301 301R 45/00 320A 45/00 320 F02M 25/07 550G F02M 25/07 550 550E 550R 550C F02B 37/12 301Q F term (reference) 3G005 DA02 EA15 FA05 FA35 GA04 GB24 GE01 HA05 HA12 JA12 JA13 JA23 JA24 JA36 JA39 JA51 JB02 3G06A GAA GA04 GA06 GA08 GA12 GA14 GA17 GA21 3G084 AA01 BA07 BA20 DA01 DA02 DA05 DA10 EA11 EB08 EB11 EC06 FA02 FA10 FA11 FA12 FA20 FA29 FA33 FA37 FA38 3G092 AA02 AA06 AA07 AA17 AA18 DB03 DC09 EC01 EC08 FA01 FA06 HAZ HD07 HA24 HE01Z HE03Z HE04Z HE08Z HF08Z

Claims (2)

[Claims] 1. An exhaust gas recirculation amount adjusting means for adjusting an amount of exhaust gas recirculated from an exhaust side flow path of an internal combustion engine to an intake side flow path via an exhaust gas recirculation path, and a turbine according to a nozzle vane opening degree. A variable-capacity turbocharger having an adjustable capacity; and a supercharging pressure supplied to the intake-side flow passage by the variable-capacity turbocharger by adjusting the turbine capacity by adjusting the nozzle vane opening. A turbine capacity adjusting means for adjusting the exhaust gas recirculation amount, or an exhaust gas recirculation amount detecting means for detecting a control state amount changing corresponding to the exhaust gas recirculation amount; and the exhaust gas recirculation amount or the control state. The target value of the exhaust gas recirculation amount with respect to the operating state of the internal combustion engine and the detected value thereof, or the target value of the control state amount corresponding to the target value of the exhaust gas recirculation amount and the detection value thereof Bias with Feedback control means for performing feedback control via the exhaust gas recirculation amount adjusting means so as to eliminate the exhaust gas recirculation amount, and when the exhaust gas recirculation amount is not controlled to at least “0”, the nozzle vane opening degree with respect to the operating state. An operation control device for an internal combustion engine, comprising: a supercharging pressure control unit that controls the supercharging pressure via the turbine capacity adjustment unit by setting a predetermined opening degree. 2. The turbocharger according to claim 1, wherein an actual turbine capacity value for a capacity command value instructed to said turbine capacity adjusting means for adjusting said turbine capacity is set for each individual turbocharger. A correction value for correcting to the command value is set in advance, and the supercharging pressure control means controls the turbine capacity adjusting means using a correction capacity command value obtained by correcting the capacity command value with the correction value. The operation control device for an internal combustion engine according to claim 1, wherein: