JP2000170580A - Control device for engine with supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly maintain the efficiency, etc., of a supercharger, by effectively and cooperatively controlling an exhaust reflux valve and a supercharger in an operation region being performing an exhaust reflux. SOLUTION: A device, equipping a turbo-supercharger and an EGR device, and also having a means for controlling an EGR valve so as to equate an air- fuel ratio with a target air-fuel ratio; is equipped with a suction pressure sensors 24 for detecting supercharging pressure, an air flow sensor 33 for detecting fresh air quantity to an engine, and a controlling means 40. The means 40 controls at least one side of the driving quantity of the turbo-supercharger and the opening quantity of the EGR valve, so that the supercharging pressure and the fresh air quantity can be increased/decreased in accordance with each other, following the change of an operation condition in an operation region making exhaust reflux.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a supercharged engine mounted on an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, an EGR passage (exhaust recirculation passage) for recirculating exhaust gas of a diesel engine into an intake passage as disclosed in Japanese Patent Application Laid-Open No. 8-338318, for example.
And an exhaust gas recirculation device for a diesel engine having an EGR valve (exhaust gas recirculation valve) provided in the EGR passage for adjusting the amount of recirculated exhaust gas, in order to suppress generation of smoke while reducing NOx. A target value of the excess air ratio (air-fuel ratio) is determined, and the EGR valve is controlled so as to eliminate a deviation between the target value and a detected value.

That is, in a diesel engine, a relatively large amount of E is used in an operating region where the excess air ratio is large, such as a low to medium load region.
Although the NOx is reduced by performing the GR,
If the air-fuel ratio becomes smaller than a certain level due to an increase in GR, smoke tends to increase sharply.
In order to achieve both reduction and smoke reduction, it is necessary to adjust the EGR amount so as to maintain the air-fuel ratio at a predetermined value.
For this reason, in the device of the above publication, the target value of the excess air ratio corresponding to the air-fuel ratio is set according to the operating state,
The actual excess air ratio is detected by the excess air ratio detecting means. If the actual excess air ratio becomes larger than the target excess air ratio, the actual excess air ratio is reduced by opening the EGR valve and increasing the exhaust gas recirculation amount. Conversely, when the actual excess air ratio becomes smaller than the target excess air ratio, the EGR valve is closed to reduce or cut off the exhaust gas recirculation amount.
Control for increasing the actual excess air ratio is executed.

Further, as shown in Japanese Patent Application Laid-Open No. 10-47070, for example, a turbocharger turbine is provided with variable blades for changing the exhaust flow area to thereby change the supercharging state according to the operation state. There is also known a turbocharged engine that can be controlled.

[0005]

As described above, a supercharger capable of controlling a supercharging state by a variable blade or the like and an apparatus configured to feedback-control an exhaust gas recirculation valve according to an air-fuel ratio are described. Although each is known, in the past, both were individually controlled independently of each other.

However, the control of the exhaust gas recirculation valve and the control of the supercharging state affect each other. For example, when the opening degree of the variable blade is controlled as the control of the supercharging state, when the opening degree changes, the exhaust pressure increases. Affects the exhaust gas recirculation by changing
On the other hand, if the opening degree of the exhaust gas recirculation valve changes, the exhaust energy released to the exhaust gas recirculation passage changes, which affects the supercharging state (supercharging amount and supercharging pressure). Therefore, if the control of the exhaust gas recirculation valve and the control of the supercharging state are individually performed and the mutual influences are not adjusted, the inappropriateness may be affected and the efficiency of the supercharger may be deteriorated.

In view of such circumstances, the present invention effectively coordinates the control of the exhaust gas recirculation valve and the control of the supercharger in the operating region where the exhaust gas recirculation is performed, thereby improving the efficiency of the supercharger. It is intended to provide a control device for a supercharged engine that can be maintained at a constant speed.

[0008]

The invention according to claim 1 is
A supercharger and an exhaust gas recirculation device that takes out exhaust gas from the exhaust passage and recirculates the exhaust gas to an intake passage downstream of the supercharger via an exhaust gas recirculation valve, and the exhaust gas recirculation valve so that the air-fuel ratio becomes the target air-fuel ratio. In a control device for a supercharged engine having a control means, a supercharging pressure detecting means for detecting a supercharging pressure, an intake air amount detecting means for detecting a fresh air amount to the engine, and exhaust gas recirculation are performed. In the operating region, at least one of the driving amount of the supercharger and the opening amount of the exhaust gas recirculation valve is adjusted so that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other with a change in the operation state. It is provided with control means for controlling.

According to the device of the present invention, the exhaust gas recirculation valve is controlled so that the air-fuel ratio becomes the target air-fuel ratio, and thus N
The operation of the supercharger and the exhaust gas recirculation valve are performed so that the Ox and the smoke are reduced, the emission is improved, and while the air-fuel ratio is adjusted in this way, the supercharging pressure and the fresh air amount increase and decrease corresponding to each other. Of the supercharger, the efficiency of the supercharger is kept good.

In the apparatus according to the present invention, the control means controls the driving amount of the supercharger and the exhaust gas recirculation so that the supercharging pressure and the fresh air amount increase in correspondence with each other when the engine is accelerated. It suffices if at least one of the opening amount of the valve is controlled (claim 2).

The control means calculates a pressure ratio, which is a ratio between the downstream pressure and the upstream pressure of the supercharger, based on the output of the supercharging pressure detecting means. At least one of the drive amount of the supercharger and the opening amount of the exhaust gas recirculation valve may be controlled so that the air amount increases and decreases corresponding to each other.

Preferably, the control means includes means for controlling the opening amount of the exhaust gas recirculation valve based on the output of the intake air amount detecting means so that the air-fuel ratio becomes the target air-fuel ratio. . With this configuration, the control of the exhaust gas recirculation valve for setting the air-fuel ratio to the target air-fuel ratio is accurately performed based on the output of the intake air amount detecting means.

The control means sets a target supercharging pressure and a target fresh air amount in accordance with an operation state, and calculates a deviation between the supercharging pressure detected by the supercharging pressure detecting means and the target supercharging pressure. The driving amount of the supercharger and the opening amount of the exhaust gas recirculation valve are controlled in accordance with a deviation between the new air amount detected by the intake air amount detecting means and the target new air amount. preferable.

In this manner, the supercharging pressure and the air-fuel ratio are controlled to appropriate values by controlling the driving amount of the supercharger and the opening amount of the exhaust gas recirculation valve, respectively. The control state is adjusted such that the supply pressure and the fresh air amount increase and decrease correspondingly.

Further, the supercharger is a turbocharger provided with exhaust flow area changing means for changing an exhaust flow area to the turbine, and the exhaust recirculation device takes out exhaust gas from upstream of the turbine. In the case where the recirculation is performed to the intake passage downstream of the compressor of the turbocharger, the control means increases or decreases the supercharging pressure and the fresh air amount in accordance with a change in the operation state. As described above, at least one of the exhaust gas flow area varying means and the opening amount of the exhaust gas recirculation valve may be controlled (claim 6).

With this configuration, the supercharging amount is controlled by the exhaust flow area variable means, and the operation of the exhaust flow area variable means and the control of the exhaust gas recirculation valve depend on the supercharging pressure and the fresh air as the operating state changes. The quantities are adjusted so as to satisfy the relationship of increasing and decreasing corresponding to each other.

In the case where a variable blade that forms a nozzle whose opening degree can be changed with respect to the turbine of the turbocharger is provided as the exhaust flow area changing means, the control means controls the variable in the operating region where the exhaust gas recirculation is performed. The opening of the variable wing and the exhaust gas recirculation valve are controlled such that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other as the operating state changes, while keeping the opening of the blade at a partial opening within a predetermined range. It suffices if at least one of the quantity is controlled. If the opening degree of the variable blade is set to a partial opening degree within a predetermined range, the supercharging pressure can be effectively adjusted.

Further, at least one of the exhaust flow area variable means and the opening of the exhaust gas recirculation valve so that the rate of change of the supercharging pressure with respect to the fresh air amount is within a predetermined range in which the overall turbo efficiency or the compressor efficiency is high. (Claim 8) is preferable. With this configuration, when the fresh air amount and the supercharging pressure change according to the operation state, the state where the overall turbo efficiency or the compressor efficiency is high is maintained.

It is also effective that the control by the control means is performed as follows.

That is, in the operating region where the exhaust gas recirculation is performed, when the rate of increase of the supercharging pressure with respect to the increase of the fresh air amount is larger than a predetermined value, the exhaust flow area variable means suppresses the increase of the supercharging pressure. If the control is performed in the direction (claim 9), when there is a tendency that the supercharging pressure rises unnecessarily large without increasing the fresh air amount so much, this can be adjusted.

Also, in a predetermined engine speed range in which exhaust gas recirculation is performed, the exhaust flow area is set such that the supercharging pressure and the fresh air amount to the engine increase and decrease corresponding to each other from a low load range to a high load range. If at least one of the variable means and the opening amount of the exhaust gas recirculation valve is controlled (claim 10), the supercharging pressure and the fresh air amount change according to the operating state in an appropriate correspondence. State is ensured from low load to high load.

Further, in controlling the supercharging pressure and the fresh air amount to the engine to increase or decrease corresponding to each other, the opening amount of the exhaust gas recirculation valve may be controlled with priority. ), A state in which the exhaust gas recirculation amount is properly adjusted is secured.

Further, at least on the low rotation speed side of the operating region where the exhaust gas recirculation is performed, both the exhaust flow area variable means and the opening amount of the exhaust gas recirculation valve may be controlled. Alternatively, control may be performed by giving priority to the exhaust flow area variable means on the low rotation speed side of the operating region where exhaust gas recirculation is performed, and by giving priority to the opening amount of the exhaust gas recirculation valve on the high rotation speed side ( Claim 13).

It is to be noted that the supercharger may be a mechanical supercharger in which the supercharging amount is adjusted by supercharging relief.

According to a fifteenth aspect of the present invention, there is provided a turbocharger provided with an exhaust flow area changing means for changing an exhaust flow area to a turbine, and exhaust gas recirculated by extracting exhaust gas from an exhaust passage upstream of the turbine. An exhaust gas recirculation device that recirculates the air to the intake passage downstream of the compressor of the turbocharger via a valve, and an engine with a supercharger having means for controlling the exhaust gas recirculation valve so that the air-fuel ratio becomes the target air-fuel ratio In the control device of the above, in the operating region where the exhaust gas recirculation is performed, the exhaust pressure is increased or decreased so that the supercharging pressure and the fresh air amount to the engine increase and decrease in accordance with the change of the operating state at least when the engine is accelerated. It is provided with control means for controlling both the flow area variable means and the opening amount of the exhaust gas recirculation valve.

According to the device of the present invention, at least at the time of acceleration of the engine, the supercharging pressure and the fresh air amount are quickly changed by controlling both the exhaust flow area variable means and the opening amount of the exhaust gas recirculation valve. Thus, a control state suitable for improving acceleration performance and improving emission during acceleration can be obtained.

In the apparatus according to the present invention, the control means may be configured such that the supercharging pressure and the fresh air amount increase and decrease sufficiently in response to a change in the operating state in an operating region where the exhaust gas recirculation valve opening is large. During acceleration from a state in which the exhaust flow area variable means and the exhaust gas recirculation valve opening are controlled outside the range in which such characteristics are obtained, the exhaust gas recirculation valve opening is reduced while the exhaust gas recirculation valve opening is decreased, and the exhaust gas circulation area is increased. It is preferable that the exhaust flow area variable means be controlled (claim 16).

In this manner, when the exhaust gas recirculation valve is accelerated from a control state in which the opening amount of the exhaust gas recirculation valve is large and the supercharging pressure and the fresh air amount do not sufficiently increase with an increase in the load as it is, the exhaust gas recirculation valve does not increase. By controlling the opening amount to decrease and the exhaust gas flow area to increase, the exhaust gas recirculation amount is reduced, the increase in fresh air amount is promoted, and the acceleration performance and emission are promptly improved.

Also, when accelerating from a low engine speed region where the exhaust gas recirculation valve opening is larger than the other operating regions, the exhaust gas recirculation valve variable means is designed to increase the exhaust gas recirculation area while reducing the exhaust gas recirculation valve opening. Is controlled (claim 17). Alternatively, when accelerating the engine from the low rotation and low load range,
The exhaust flow area varying means may be controlled so that the exhaust flow area increases while reducing the exhaust gas recirculation valve opening amount.

In this manner, the increase in the fresh air amount is promoted when accelerating from the low engine speed region or when the engine is accelerating from the low engine speed and low load region where the exhaust gas recirculation valve opening is larger than the other operating regions. As a result, the acceleration performance and the emission are promptly improved.

It is preferable that the decrease in the opening of the exhaust gas recirculation valve during the acceleration is restricted to a predetermined lower limit (claim 19). In this case, the opening of the exhaust gas recirculation valve during the acceleration is reduced. It is possible to prevent a situation in which the size becomes too small to cause an increase in NOx.

Preferably, both the amount of change in the opening of the exhaust gas recirculation valve and the amount of change in the area of exhaust gas flow during the acceleration are set to be larger toward the lower engine speed. In other words, in the steady state, the opening amount of the exhaust gas recirculation valve is increased and the exhaust flow area is reduced toward the low rotation speed and low load side. By increasing the reduction and the increase in the exhaust circulation area, the acceleration performance and the emission can be effectively improved.

Further, it is preferable that the ratio of the change amount of the exhaust gas recirculation valve opening amount to the change amount of the exhaust gas circulation area at the time of the acceleration is set to be larger toward the lower engine speed. Further, the control means may prioritize a change in the exhaust gas recirculation valve opening amount when accelerating relatively on the low engine speed side, and prioritize a change in the exhaust flow area when accelerating on the high engine speed side. (Claim 22) is effective.

That is, during steady operation on the low engine speed and low load side, the opening amount of the exhaust gas recirculation valve is large.
By giving priority to decreasing the exhaust gas recirculation valve opening during acceleration from this state, the effect of suppressing exhaust gas recirculation and promoting an increase in fresh air volume is enhanced, while on the other hand, on the high engine speed side where the exhaust flow velocity and flow rate are large. Since the change in the exhaust flow area quickly affects the exhaust pressure and the related exhaust gas recirculation amount, etc., priority is given to the change in the exhaust flow area when accelerating on the high engine speed side, so that the acceleration performance and emission can be improved with good responsiveness. Is improved.

In addition to the above configuration, the intake air amount detecting means for detecting the amount of fresh air to the engine and the actual fresh air amount detected by the intake air amount detecting means are based on the target air-fuel ratio. It is preferable to provide a means for controlling the exhaust gas recirculation valve so that the desired fresh air amount is obtained. With this configuration, the control of the exhaust gas recirculation valve for setting the air-fuel ratio to the target air-fuel ratio is accurately performed based on the actual fresh air amount and the target fresh air amount obtained from the target air-fuel ratio.
In a normal state, the exhaust gas recirculation amount is appropriately adjusted by such control, and at the time of a specific acceleration, the acceleration performance is improved by the above-described control.

Further, a supercharging pressure detecting means for detecting a supercharging pressure, and an exhaust flow area variable means such that the actual supercharging pressure detected by the supercharging pressure detecting means becomes a preset target supercharging pressure. It is preferable to provide means for controlling
4). With this configuration, the control of the supercharging pressure is performed with high accuracy. In normal operation, the supercharging pressure is appropriately adjusted by such control, and at the time of specific acceleration, the acceleration performance is improved by the above-described control.

[0037]

FIG. 1 shows an embodiment of a turbocharged engine equipped with a control device according to the present invention. The illustrated engine is a diesel engine, and an intake passage 2 and an exhaust passage 3 are connected to an engine body 1 of the diesel engine. This engine is equipped with a turbocharger 5. The turbocharger 5 is provided in a compressor 6 provided in an intake passage 2, and provided in an exhaust passage 3 for driving the compressor 6 by exhaust energy. And an exhaust flow area changing means including a variable blade 8 and an actuator 9 for driving the same. In addition, this engine has EGR
An EGR device (exhaust gas recirculation device) having a passage 11 and an EGR valve (exhaust gas recirculation valve) 12 provided in the EGR passage 11 is provided.

The structure of each part of the engine will be described in detail. Each cylinder 14 of the engine body 1 is provided with a multi-injection fuel injection valve 15 for injecting fuel into the combustion chamber. The fuel inlet side of these fuel injection valves 15 is connected to the distribution passage 1.
The common rail 17 is connected to a common rail (common pipe) 17 via a fuel injection pump 18. The common rail 17 is connected to a fuel injection pump 18. It is sent to a valve 15. Each fuel injection valve 15 has a structure capable of controlling a fuel injection time and an injection timing according to a control signal. The fuel outlet side of each fuel injection valve 15 is connected to a return passage 19.

In the intake passage 2, an air flow sensor 21, a compressor 6 of the turbocharger 5, an intercooler 22, and a surge tank 23 are disposed in this order from the upstream side. An intake pressure sensor 24 is provided. In the exhaust passage 3,
The turbine 7 of the turbocharger 5 and the catalytic converter 25 are provided.

The turbocharger 5 comprises a VGT (Variable Geometry Turbo) having a number of variable blades 8 forming nozzles around a turbine 7 as shown in FIG. That is, the turbocharger 5 (hereinafter, VG)
T5) is obtained by adjusting the angle of the variable wing 8 in FIG.
The opening degree of the variable blade 8, that is, the nozzle opening area (exhaust flow area to the turbine) is variable from the fully closed state shown in FIG. 2A (minimum flow area) to the fully open state shown in FIG. Thus, the turbine efficiency is controlled.

As shown in FIG. 1, an actuator 9 for driving the variable wing 8 is a duty-controllable solenoid valve 2.
6 is connected to a vacuum pump 27 via an actuator 6, and the duty of the solenoid valve 26 is controlled so that the actuator 9
The ratio of the introduction of the negative pressure and the atmospheric pressure to the VGT 5 is adjusted, whereby the variable blade opening of the VGT 5 is controlled.

The EGR passage 11 has one end connected to the exhaust passage 3 on the upstream side of the turbine 7, and the other end connected to the downstream side of the compressor 6 in the intake passage 2, for example, a surge tank 23. It is connected. The EGR valve 12 is connected to a vacuum pump 27 via a duty-controllable solenoid valve 28.
By controlling the duty of the electromagnetic valve 28, the introduction ratio of the negative pressure to the negative pressure chamber of the EGR valve 12 and the atmospheric pressure is adjusted, so that the opening degree (opening amount) of the EGR valve 12 is controlled. Has become.

The fuel injection valve 15 and the solenoid valves 26 and 28
, A control signal is output from a control unit (ECU) 30. The ECU 30 receives signals from the air flow sensor 21 and the intake pressure sensor 24, and further includes an accelerator opening sensor 31 for detecting an accelerator opening, a crank angle sensor 32 for detecting a crank angle of an engine, and a common rail 17 A signal from a common rail pressure sensor 33 for detecting the fuel pressure in the inside is also input.

The ECU 30 determines that the fuel injection valve 1
5 controls the fuel injection amount and the injection timing from the fuel injection valve 15, and the control signal (duty signal) output to the solenoid valve 26 controls the variable blade opening of the VGT 5. The opening of the EGR valve 12 is controlled by a control signal (duty signal) output to the electromagnetic valve 28.

As shown in FIG. 3, the ECU 30 controls the fuel injection amount of the fuel injection valve 15 by a fuel injection amount control means 35, a common rail pressure control means 36 by which the fuel pressure in the common rail 17 is controlled. Control of VGT5 and E
And control means 40 for performing control in association with the control of the GR valve 12.

The fuel injection amount control means 35 controls the accelerator operation amount acc detected by the accelerator operation amount sensor 31.
el and the engine speed Ne detected by measuring the cycle of the crank angle signal by the engine speed detecting means 34, the target torque trqsol of the engine is read from a preset map 37, and the target torque trqsol is read. , The engine speed Ne, and the actual fresh air amount F detected by the air flow sensor 21
Based on Air, a target fuel injection amount Fsol is read from a preset three-dimensional map 38, and fuel is calculated based on the target fuel injection amount Fsol and the fuel pressure CRP in the common rail 17 detected by the common rail pressure sensor 21. The fuel injection amount is controlled by adjusting the excitation time of the injection valve 15.

The common rail pressure control means 36 reads a target common rail pressure CRPsol from a map 39 set in advance based on the target torque trqsol and the engine speed Ne, and calculates the target common rail pressure CRPsol and the detected fuel pressure CRP. , A fuel pressure adjusting means (not shown) provided in the fuel system is controlled.

Further, the control means 40 controls the EGR valve 28 so that the EGR is performed at least in the partial load range and the air-fuel ratio attains the target air-fuel ratio at this time. A computing means 41 for controlling at least one of the VGT 5 and the EGR valve 12 so that the supercharging pressure and the fresh air amount increase and decrease in correspondence with each other, and computes an EGR valve drive command value for the EGR valve control. When,
It includes a calculation means 42 for calculating a VGT drive command value for VGT control, and a coordination control means 43 for coordinating EGR valve control and VGT control.

The EGR valve drive command value calculating means 41
Is a predetermined partial load region excluding the idle operation region, the high load region, and the deceleration operation region, and the air-fuel ratio is the target air-fuel ratio A /
An EGR valve drive command value is calculated in order to perform feedback control of the EGR valve 12 so as to be Fsol. That is, the target torque trqsol and the engine speed Ne
The target air-fuel ratio A / Fsol is read out from a map 44 set in advance based on the target air-fuel ratio A / Fso.
The target fresh air amount FAsol is calculated by the target fresh air amount calculation unit 45 based on l and the target fuel injection amount Fsol, and the target fresh air amount FAsol is sucked into the combustion chamber of the engine body 1. The value and the actual fresh air amount FAir detected by the airflow sensor 33 are input to the calculating means 41.

The calculating means 41 calculates P in accordance with the deviation between the target fresh air amount FAsol and the actual fresh air amount FAir.
A feedback control amount for driving the EGR valve 12 is eliminated as an EGR valve driving command value by the I control or the like so as to eliminate the deviation.

The VGT drive command value calculating means 42 is provided by EG
In the operating region where R is performed, in order to perform feedback control of the variable blades of the VGT 5 so that the supercharging pressure becomes the target supercharging pressure,
The VGT drive command value is calculated. That is, the target supercharging pressure Bstsol is read from the map 46 set in advance based on the target torque trqsol and the engine speed Ne, and the actual supercharging detected by the target supercharging pressure Bstsol and the intake pressure sensor 24 is performed. The pressure Bst is input to the calculation means 42.

Then, the calculating means 42 calculates P P according to the deviation between the target supercharging pressure Bstsol and the actual supercharging pressure Bst.
A feedback control amount for driving the variable wing 8 of the VGT 5 is calculated as a VGT drive command value so as to eliminate the above deviation by I control or the like.

The cooperative control means 43 basically outputs the EGR valve drive command value and the VGT drive command value to the EGR valve drive solenoid valve 28 and the VGT drive solenoid valve 26, respectively. In the control state, it is determined whether or not characteristics such that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other with a change in the operating state are obtained. If such characteristics cannot be obtained, the EGR valve is used. At least one of the drive command value and the VGT drive command value is corrected.

Here, the opening degree of the EGR valve 12 and the VGT 5
The influence of the variable blade opening degree on the characteristics of the change of the supercharging pressure and the change of the fresh air amount according to the change of the operation state will be described with reference to the experimental data of FIG. 4 and FIG.

FIGS. 4A to 5I and FIGS.
(I) shows the pressure ratio and the air flow rate (fresh air amount) when the engine load is changed by fixing the opening of the EGR valve 12 and the variable blade opening of the VGT 5 and changing the fuel injection amount.
FIG. 4 is a graph showing data obtained by experimentally examining the characteristics of the change in the pressure (hereinafter, referred to as pressure ratio / air flow characteristics).
(A) to (i) are pressure ratio / air flow rate characteristics when the opening of the EGR valve 12 and the variable blade opening of the VGT 5 are set to various values when the engine speed is set to 1500 rpm, FIG.
(A) to (i) are pressure ratio / air flow characteristics when the opening of the EGR valve 12 and the variable blade opening of the VGT 5 are set to various values when the engine speed is set to 2000 rpm.

The above pressure ratio is determined by the intake pressure P1 (supercharging pressure) downstream of the compressor 6 and the intake pressure P1 upstream of the compressor 6.
This is a ratio (P1 / P0) to 0 (substantially atmospheric pressure), and is a value proportional to the supercharging pressure when the intake pressure P0 upstream of the compressor 6 is constant (substantially 1 atmospheric pressure). Therefore, the pressure ratio / air flow rate characteristic corresponds to a change in the supercharging pressure and a change in the intake air amount due to a change in the operation state. In addition, the opening degree of the EGR valve shown in the figure is such that 0% is fully closed and 100% is fully open.
The variable blade opening of the VGT is 0% fully open and 100% fully closed.

As shown in these figures, the pressure ratio and the air flow rate characteristic vary depending on the opening degree of the EGR valve 12 and the variable blade opening degree of the VGT 5, but the pressure ratio and the air flow rate change with respect to the change of the operation state. Are increased or decreased corresponding to each other, and when the engine is accelerated, the supercharging pressure and the fresh air amount increase correspondingly to each other, that is, a characteristic that rises to the right in the graph. If the inclination (change rate of the pressure ratio with respect to the air flow rate) is appropriate, it means that the overall turbo efficiency or the compressor efficiency is high. It is preferable that such a relationship between the pressure ratio and the intake flow rate can be obtained in a wide range from a relatively low load side to a relatively high load side. For example, in FIG.
Characteristics such as (i) are relatively preferable characteristics. And
By setting the opening degree of the EGR valve 12 and the variable blade opening degree of the VGT 5 within a specific range, the above-described preferable characteristics can be obtained.

On the other hand, when the opening degree of the EGR valve 12 and the variable blade opening degree of the VGT 5 are out of the above specific ranges, for example, E
If the opening of the GR valve 12 is too large or if the variable blade opening of the VGT 5 is too small, the overall slope of the turbocharger or the compressor efficiency will decrease, and the inclination will increase, and the intake flow rate will not increase much. However, the pressure ratio tends to increase too much, and the intake air flow rate hardly increases, which is not preferable.

Therefore, the ranges of the ECR valve opening and the VGT variable blade opening at which the preferable pressure ratio / air flow characteristics as described above are obtained are checked in advance, and the corresponding EGR valve driving command value and VGT driving command value are determined. A range of values is an allowable range, and such an allowable range is set according to an operating state such as an engine speed. And the cooperative control means 43
Is adjusted when the EGR valve drive command value and the VGT drive command value deviate from the allowable ranges.

FIG. 6 is a flowchart showing an example of the control by the control means 40. When the control of this flowchart starts, first, in step S1, the actual supercharging pressure,
The actual fresh air amount, the target supercharging pressure and the target fresh air amount are read, and in step S2, the calculation of the EGR valve drive command value EGRsol according to the deviation between the actual fresh air amount and the target fresh air amount, and the actual supercharging pressure Drive command value VGTs according to the deviation between the target and the target supercharging pressure
ol is calculated.

Next, in step S3, it is determined whether or not the EGR valve drive command value EGRsol and the VGT drive command value VGTsol are within the allowable range. If it is within the allowable range, the EGR valve drive command value EGRso
1 and the VGT drive command value VGTsol are output as they are (step S4).

If not within the allowable range, the EGR valve 1
The EGR valve drive command value EGRsol is output as it is so as to give priority to the feedback control of Step 2 (Step S
5) On the other hand, the VGT drive command value VGTsol is changed toward the allowable range (step S6). For example, when the EGR is out of the allowable range on the side with more EGR, the VGT drive command value VGTsol is decreased. And V after change
GT drive command value VGTsol is output (step S
7).

According to the apparatus of the present embodiment as described above,
By performing feedback control of the ECR valve 12 so that the air-fuel ratio becomes the target air-fuel ratio, NOx and smoke are reduced, and emission is improved. On the other hand, the supercharging state is adjusted by performing feedback control of the VGT 5 so that the supercharging pressure becomes the target supercharging pressure. Then, the charging efficiency is increased by the supercharging, and the fresh air amount is secured while the EGR amount is increased, so that the emission improvement effect is enhanced.

Further, the control of the EGR valve 12 and the control of the VGT 5 are adjusted by the processing of steps S3 to S7 as the cooperative control means 43, and the efficiency of the turbocharger (turbo total efficiency or compressor efficiency) and the like are adjusted. It is kept well and fuel economy is improved.

That is, if the opening degree of the EGR valve 12 changes even if the variable blade opening degree of the VGT 5 is constant, the amount of supercharging and the supercharging pressure change because the exhaust energy released to the EGR passage 11 changes. The control of the EGR valve 12 and the control of the VGT 5 such that the EGR amount changes with a change in the exhaust pressure when the variable blade opening of the VGT 5 changes even if the opening of the VGT 5 is constant.
Since these controls affect each other, simply performing these controls individually does not necessarily result in a state in which both controls cooperate properly, and the efficiency of the turbocharger may be degraded. In addition, the basic control amount, control range,
It is conceivable to adjust the mutual influence of the two controls by setting the control conditions such as the control gain appropriately in advance.However, even in such a case, there is an individual difference in the characteristics of the engine and the supercharger. Since the degree of influence of both controls changes, it is difficult to always properly adjust both controls.

On the other hand, according to the apparatus of this embodiment,
Regarding the opening degree of the EGR valve 12 and the variable blade opening degree of the VGT 5,
An allowable value that satisfies the condition that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other with a change in the operating state is determined, and E
When the command value obtained by the feedback control of the GR valve 12 and the feedback control of the VGT 5 deviates from the allowable value, the corresponding adjustment is performed, so that an appropriate pressure ratio / air flow rate characteristic can always be obtained. The efficiency of the feeder can be kept good.

In this embodiment, in order to give priority to the feedback control of the EGR valve 12, the above-described step S3 is performed.
When it is determined that the value is out of the allowable range, the EGR valve drive command value EGRsol obtained according to the difference between the actual fresh air amount and the target fresh air amount is output as it is, and the VGT drive command value VGTsol is changed. Therefore, good tracking of the air-fuel ratio to the target value is maintained.
When the variable blade opening of the VGT 5 changes due to the change of the VGT drive command value VGTsol, it affects the air-fuel ratio, and the EGR valve 1 is controlled by feedback control according to the air-fuel ratio.
2 is also adjusted, and by repeating such control, the coordination between the control of the EGR valve 12 and the control of the VGT 5 is appropriately performed.

In the control example shown in FIG.
R valve drive command value EGRsol and VGT drive command value VG
When Tsol is out of the allowable range, only the VGT drive command value VGTsol is changed, but both command values may be changed by a predetermined amount. On the low rotation side, control of the VGT 5 is prioritized in order to avoid insufficient supercharging,
On the high rotation side, control of the EGR valve 5 may be prioritized.

FIG. 7 shows a second example of the control by the control means 40.
Is shown in a flowchart. When the control of this flowchart starts, first, in step S11, the actual supercharging pressure, the actual fresh air amount, the target supercharging pressure, and the target fresh air amount are read, and in step S12, the actual fresh air amount and the target fresh air amount are compared. The calculation of the EGR valve drive command value EGRsol according to the deviation and the calculation of the VGT drive command value VGTsol according to the difference between the actual supercharging pressure and the target supercharging pressure are performed. Further, step S1
In step 3, the change rate of the fresh air amount is determined from the difference between the current value and the previous value of the actual fresh air amount, and the change rate of the supercharging pressure is similarly calculated. In step S14, the change rate of the fresh air amount is determined. The change rate of the supercharging pressure with respect to the fresh air amount is calculated from the supercharging pressure change rate.

Next, in step S15, it is determined whether or not the change rate has a predetermined slope (having a certain allowable range). If the change rate is the predetermined slope, the VGT drive command value V
GTsol and the EGR valve drive command value EGRsol are output (steps S16 and S17).

If the change ratio is not the predetermined gradient, it is determined in step S18 whether the gradient is larger than the predetermined gradient, that is, whether the gradient is too large or too small. If the inclination is too large, the VGT drive command value VGTsol is decreased (step S19),
If the inclination is too small, the VGT drive command value VGTsol
Is increased (step S20).

According to this control example, the above step S14
Then, the change rate of the supercharging pressure with respect to the fresh air amount is obtained, that is, the change rate corresponding to the gradient of the pressure ratio / air flow characteristic shown in FIGS. When the inclination deviates from the appropriate range, the VGT drive command value VGTsol is changed. In this case, if the inclination is too large, the supercharging pressure tends to increase too much when the engine load increases, although the fresh air amount does not increase so much. Therefore, the VGT drive command value VGTs
ol is decreased so as to increase the variable blade opening, and if the inclination is too small, the boost pressure tends to be hard to increase. Therefore, the VGT drive command value VGTsol is increased to reduce the variable blade opening. It is adjusted in the direction.

In this way, the control state is adjusted so that the inclination is optimized, and the efficiency and the like of the supercharger can be kept good.

In the above control example, the supercharging pressure and the fresh air amount are detected and the change ratio of the supercharging pressure to the new air amount is examined. Then, the pressure ratio and the fresh air amount are obtained, and the change ratio of the pressure ratio with respect to the new air amount is within an appropriate range, that is, the pressure ratio and the intake air amount are increased and decreased at an appropriate change ratio corresponding to each other. May be adjusted.

FIG. 8 shows a third example of the control by the control means 40.
Is shown in a flowchart. When the control of this flowchart starts, first, in step S31, the actual supercharging pressure, the actual fresh air amount, the target supercharging pressure, and the target fresh air amount are read, and in step S32, the actual fresh air amount and the target fresh air amount are compared. The calculation of the EGR valve drive command value EGRsol according to the deviation and the calculation of the VGT drive command value VGTsol according to the difference between the actual supercharging pressure and the target supercharging pressure are performed.

Subsequently, in step S33, the accelerator opening and fuel injection amount are read, and in step S34, it is determined whether or not the engine is accelerating by examining the accelerator opening and the change rate of the fuel injection amount. If the engine is accelerating, in step S35, it is determined whether or not the EGR valve drive command value EGRsol and the VGT drive command value VGTsol are within the allowable range (a range in which a preferable pressure ratio / air flow rate characteristic is obtained). Is determined.

If it is determined in step S34 that the vehicle is not accelerating, the EGR valve drive command value EGRsol
And the VGT drive command value VGTsol is output as it is (step S36), and also when the EGR valve drive command value EGRso is determined to be within the allowable range in step S35.
1 and the VGT drive command value VGTsol are output as they are (step S37).

At the time of acceleration, if the EGR valve drive command value EGRsol and the VGT drive command value VGTsol are not within the allowable ranges (YES in step S34 and NO in step S35), for example, the EGR amount is increased. If the EGR valve 12 is out of the allowable range in a state where the opening degree of the EGR valve 12 is increased in a low engine speed region or the like,
As in steps S38 to S42, the opening of the EGR valve 12 and the variable blade opening of the VGT 5 are controlled.

That is, the engine speed is read in step S38, and in step S39, the EGR valve drive command value EGRsol is corrected to decrease by an amount corresponding to the engine speed in order to reduce the opening of the EGR valve 12, and step S40. Output the corrected EGR valve drive command value EGRsol. Further, in step S41, the VGT drive command value VGTsol is corrected to decrease by an amount corresponding to the engine speed in order to increase the variable blade opening of the VGT 5, and in step S42, the corrected VGT drive command value VGTsol is output.

The amount of decrease in the EGR valve drive command value EGRsol (the amount of decrease in the EGR valve opening) and the amount of decrease in the VGT drive command value VGTsol (the amount of increase in the VGT variable blade opening)
, Respectively, so that it becomes larger on the low engine speed side,
It is set in advance in a table or the like corresponding to the engine speed.

According to this control example, during acceleration, the EGR valve drive command value EGRsol and the VGT drive command value VGTs
If ol is within the allowable range (a range in which the pressure ratio and air flow characteristics can be obtained such that the boost pressure and the new amount increase and decrease sufficiently in correspondence with changes in the operating state), the value is output. As a result, a state in which the supercharging pressure and the fresh air amount increase with an increase in the load (an increase in the fuel injection amount) while maintaining good emission is ensured.

During acceleration, the opening degree of the EGR valve 12 and V
When the variable blade opening of the GT 5 is in a control state outside the allowable range, the opening of the EGR valve 12 is reduced and V
By simultaneously increasing the variable blade opening of the GT5, the acceleration performance is enhanced, and deterioration of the emission is prevented.

More specifically, in the idling operation region and the low-speed low-load region in the vicinity thereof, the opening of the EGR valve 12 is made relatively large and the variable blade opening of the VGT 5 is increased in order to increase the EGR amount. May be reduced to some extent and the control state may be out of the allowable range. For example, when the EGR valve drive command value EGRsol is about 60% and the VG
When the T drive command value VGTsol is controlled to be 50%, the control state may be brought to the characteristic shown in FIG. 4B. Even with such characteristics, there is no problem in a steady state. However, if acceleration is performed in this control state, the boost pressure and the fresh air amount hardly increase, so that sufficient acceleration performance cannot be obtained.

For this reason, when accelerating from this control state, it is necessary to change the control state of the EGR valve 12 and the VGT 5 in order to increase the supercharging pressure and the fresh air amount. Assuming that only the EGR valve 12 is controlled in the direction of decreasing the opening without changing the EGR valve, for example, from the state shown in FIG. 4B to the state where the suitable characteristics as shown in FIG. It is necessary to greatly change the opening degree of No. 12, and the time required for the opening degree deteriorates the acceleration response. It is conceivable to reduce the variable blade opening of the VGT 5 in order to increase the supercharging efficiency. However, if the variable blade opening is reduced during acceleration from a low rotation and low load region in a state where EGR is performed, the exhaust pressure is reduced. Rises and EGR passage 1
Since the EGR amount increases due to the increase in the differential pressure between the two ends of the fuel cell 1, the fresh air amount temporarily decreases, and on the contrary, the output increase at the initial stage of acceleration is hindered, and smoke is more likely to occur.

On the other hand, in this control example, the EGR valve drive command value E is set in a low-speed low-load region such as the idling operation region.
During acceleration from a state in which the GRsol and the VGT drive command value VGTsol are out of the allowable range, the EGR valve drive command value EGRsol is reduced, so that the opening degree of the EGR valve 12 is reduced, and the VGT drive command value VGTs
ol, the variable blade opening of the VGT 5 is increased, and the exhaust pressure is reduced due to the increase in the variable blade opening. Therefore, the EGR amount is quickly reduced, and the increase in the fresh air amount in the initial stage of acceleration is promoted. As a result, the output is increased and the generation of smoke is prevented.

Further, by changing the control state and the pressure ratio / air flow rate characteristic from, for example, the state shown in FIG. 4B to the state shown in FIG. 4F, preferable characteristics can be obtained. FIG. 4 shows the state in which only the opening degree of the EGR valve 12 is changed.
The change in the opening degree of the EGR valve 12 may be smaller than in the case where the state shown in FIG. 4B is changed to the state shown in FIG.
The time required for obtaining suitable characteristics is shortened, and the acceleration response is improved.

By these operations, even when acceleration is performed from a low rotation and low load region such as an idling operation region, the acceleration performance is greatly improved and the emission is improved.

As described above, the EGR valve drive command value EGRs
ol and the VGT drive command value VGTsol are out of the allowable range during acceleration, the opening of the EGR valve 12 is reduced and the opening of the variable blade of the VGT 5 is increased at the same time. Set according to the number,
It is effective to increase the change on the lower rotation side to improve the acceleration performance. That is, during steady operation, the opening degree of the EGR valve 12 is increased and the variable blade opening degree of the VGT 5 is decreased in order to increase the EGR amount as the engine speed decreases and the engine load decreases. When the vehicle is accelerated, the reduction of the EGR valve opening and the increase of the VGT variable blade opening are made relatively large, so that the above-described effects such as improvement in acceleration and suppression of smoke during acceleration can be obtained well. Become.

FIG. 9 shows a fourth example of the control by the control means 40.
Is shown in a flowchart. In this flowchart, steps S31, S32, S34, S36
Steps S42 to S42 perform the same processing as the steps denoted by the same reference numerals in FIG.

In this example, following steps S31 and S32, the accelerator opening, fuel injection amount and engine speed are read in step S33 ', and then it is determined whether or not the engine is accelerating (step S34). If the vehicle is accelerating, the operation range is checked in step S35 'based on the engine load (accelerator opening or fuel injection amount, etc.) and the engine speed to determine whether the opening of the EGR valve 12 is large. Is determined. Here, the region where the degree of opening of the EGR valve 12 is large is, for example, an idling operation region or a low-speed low-load region in the vicinity thereof.

In the acceleration state, the EGR valve 12
If the opening degree is large, steps S38 to S42
As a result, the opening degree of the EGR valve 12 is reduced and the VG
Control is performed so as to increase the variable blade opening of T5.

According to this control example, EGR is performed during steady operation.
During acceleration from an operation region in which the opening of the valve 12 is increased, the opening of the EGR valve 12 is reduced by decreasing the EGR valve drive command value EGRsol, and the VGT
By reducing the drive command value VGTsol and increasing the variable blade opening of the VGT 5, the EGR amount is quickly reduced and the increase in the fresh air amount in the initial stage of acceleration is promoted as in the third control example. At the same time, the state quickly changes to a state in which a suitable pressure ratio / air flow rate characteristic is obtained, so that the acceleration performance is greatly improved and the emission is improved.

FIG. 10 is a flowchart showing a fifth example of the control by the control means 40. In this flowchart, steps S31 to S38 perform the same processing as the steps with the same reference numerals in FIG.

In this flowchart, step S
34, it is determined that the vehicle is accelerating, and in step S35, the EGR valve drive command value EGRsol
When it is determined that the VGT drive command value VGTsol is not within the allowable range, the engine speed is read (step S38), and in step S51, it is determined whether or not the engine speed is in a low speed region equal to or lower than a predetermined value. Is determined.

When it is determined in step S51 that the engine speed is in the low rotation region, the ratio of the change in the EGR valve opening to the change in the exhaust gas flow area is relatively increased. The value EGRsol is corrected to decrease by a relatively large decrease amount (step S52), the corrected EGR valve drive command value EGRsol is output (step S53), and the VGT drive command value VG is output.
Tsol is corrected to decrease by a relatively small amount (step S54), and the corrected VGT drive command value VGTs is obtained.
ol is output (step S55).

If it is determined in step S51 that the engine speed is not in the low rotation region, the ratio of the change in the EGR valve opening to the change in the exhaust gas flow area is relatively reduced.
That is, the VGT drive command value VGTsol is corrected to decrease by a relatively large decrease amount (step S56), the corrected VGT drive command value VGTsol is output (step S57), and the EGR valve drive command value EGRso is provided.
1 is reduced and corrected by a relatively small reduction amount (step S
58), the corrected EGR valve drive command value EGRsol
Is output (step S59).

According to this control example, similarly to the third control example, when the opening degree of the EGR valve 12 and the variable blade opening degree of the VGT 5 during the acceleration are out of the allowable range, the EGR is performed. As the valve drive command value EGRsol is reduced, the opening degree of the EGR valve 12 is reduced, and V
As the GT drive command value VGTsol is reduced, VGT
5 is quickly increased by increasing the variable wing opening.
As the GR amount decreases, the increase in the fresh air amount in the initial stage of acceleration is promoted, and a state in which a suitable pressure ratio / air flow rate characteristic is obtained.

In particular, in the low engine speed region, the EGR valve opening is increased at a steady state, and a change in the EGR valve opening greatly affects the fresh air amount and the like. By increasing the change amount of the valve drive command value EGRsol, that is, by giving priority to the reduction of the EGR valve opening amount, the effect of increasing the fresh air amount and improving the acceleration and emission is enhanced. On the other hand, in the high rotation region of the engine, the exhaust flow velocity and the exhaust flow rate are large, and the change in the exhaust flow area is caused by the exhaust pressure and the EGR related to it.
In this case, the amount of change in the VGT drive command value VGTsol is increased during acceleration from this state, that is, the increase in the variable wing opening of the VGT 5 is prioritized, so that acceleration responsiveness and emission are increased. The effect of improving is enhanced.

The specific structure of the device of the present invention is not limited to the above embodiment, but can be variously modified.

For example, when controlling to decrease the opening of the EGR valve 12 and increase the variable blade opening of the VGT 5 at a specific acceleration as in the control examples of FIGS. It is preferable that a predetermined lower limit value is set in advance for the amount, and the decrease in the EGR valve opening amount during acceleration is stopped to the predetermined lower limit value. By doing so, the opening amount of the EGR valve does not become too small at the time of acceleration, and an increase in NOx can be prevented.

In the above embodiment, VG is used as the supercharger.
Although the variable blade opening is controlled using T5, the wastegate valve is controlled by using a turbocharger having a wastegate passage that bypasses the turbine and a wastegate valve that opens and closes this passage. It may be. Alternatively, a mechanical supercharger having a means for relieving the supercharged air may be used to control the means for relieving the supercharged air.

[0102]

As described above, the present invention relates to an engine having a supercharger, an exhaust gas recirculation device, and a means for controlling an exhaust gas recirculation valve so that an air-fuel ratio becomes a target air-fuel ratio. In the operating region where the exhaust gas recirculation is performed, the supercharging pressure and the fresh air amount are increased and decreased correspondingly to each other. Control means for controlling at least one of the above, it is possible to reduce NOx and smoke by controlling the exhaust gas recirculation valve so that the air-fuel ratio becomes the target air-fuel ratio, thereby improving emissions, The relationship between the operation of the exhaust gas recirculation valve and the control of the exhaust gas recirculation valve can be appropriately adjusted, and the efficiency of the turbocharger can be kept good.

[0103] In addition, a turbocharger provided with an exhaust flow area variable means, an exhaust gas recirculation device, and a means for controlling an exhaust gas recirculation valve so that an air-fuel ratio becomes a target air-fuel ratio. Both the exhaust flow area variable means and the exhaust gas recirculation valve opening amount so that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other with the change of the operation state at least at the time of acceleration in the operation region where recirculation is performed. For example, if the exhaust gas recirculation valve opening is controlled to decrease the exhaust gas recirculation valve opening and increase the exhaust flow area when accelerating from a low engine speed region or the like where the exhaust gas recirculation valve opening is large, the acceleration performance and emission are promptly improved. State.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of a supercharged engine equipped with a control device according to the present invention.

FIG. 2 is a schematic diagram of a structure of a variable blade arrangement portion in a VGT as an example of a supercharger.

FIG. 3 is a block diagram showing a specific configuration of a control unit of the engine.

FIG. 4 is a graph showing pressure ratio / air flow characteristics when the opening of the EGR valve and the opening of the variable blade of the VGT are set to various values at a specific engine speed.

FIG. 5 shows an EGR at an engine speed different from that of FIG.
It is a graph which shows the pressure ratio and the air flow characteristic when the valve opening and the variable blade opening of the VGT are set to various values.

FIG. 6 is a flowchart illustrating a first example of a control operation by a control unit.

FIG. 7 is a flowchart showing a second example of the control operation by the control means.

FIG. 8 is a flowchart showing a third example of the control operation by the control means.

FIG. 9 is a flowchart showing a fourth example of the control operation by the control means.

FIG. 10 is a flowchart showing a fifth example of the control operation by the control means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine main body 2 Intake passage 3 Exhaust passage 5 Turbocharger 8 Variable blade 11 EGR passage 12 EGR valve 21 Air flow sensor 24 Intake pressure sensor 30 Control unit 40 Control means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F02D 41/02 301 F02D 41/02 301E 41/10 305 41/10 305 41/18 D 41/18 43 / 00 301R 43/00 301 301N F02M 25/07 550F F02M 25/07 550 570P 570 570F F02B 37/12 301Q (72) Inventor Tomoaki Saito 3-1, Funaka-cho, Shinchi, Aki-gun, Hiroshima Prefecture Mazda Corporation (72) Inventor Keiji Araki 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (24)

[Claims] 1. A supercharger, and an exhaust gas recirculation device that extracts exhaust gas from an exhaust passage and recirculates the exhaust gas to an intake passage downstream of the supercharger via an exhaust gas recirculation valve so that an air-fuel ratio becomes a target air-fuel ratio. A supercharged engine control device having a means for controlling an exhaust gas recirculation valve, a supercharged pressure detecting means for detecting a supercharging pressure, an intake air amount detecting means for detecting a fresh air amount to the engine, and exhaust gas. In the operating region where the recirculation is performed, the drive amount of the supercharger and the opening amount of the exhaust gas recirculation valve are adjusted so that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other according to a change in the operation state. A control device for a supercharged engine, comprising: control means for controlling at least one of them. 2. The control device according to claim 1, wherein the supercharging pressure and the fresh air amount are increased in correspondence with each other when the engine is in an acceleration state. The control device for a supercharged engine according to claim 1, wherein at least one of the amount and the amount is controlled. 3. The control means calculates a pressure ratio which is a ratio between a downstream pressure and an upstream pressure of the supercharger based on an output of the supercharge pressure detection means, and calculates the pressure ratio and a new pressure ratio for the engine. The supercharger according to claim 1 or 2, wherein at least one of a drive amount of the supercharger and an opening amount of the exhaust gas recirculation valve is controlled so that the air amount increases and decreases corresponding to each other. Engine control device. 4. The control means according to claim 1, wherein said control means includes means for controlling an opening amount of said exhaust gas recirculation valve based on an output of said intake air amount detecting means so that an air-fuel ratio becomes a target air-fuel ratio. 4. The control device for a supercharged engine according to any one of claims 3 to 3. 5. The control means sets a target supercharging pressure and a target fresh air amount according to an operation state, and calculates a deviation between the supercharging pressure detected by the supercharging pressure detecting means and the target supercharging pressure. The system according to claim 1, wherein a driving amount of the supercharger and an opening amount of the exhaust gas recirculation valve are controlled in accordance with a deviation between the new air amount detected by the intake air amount detecting means and the target new air amount. The control device for a supercharged engine according to any one of claims 1 to 3. 6. The turbocharger is a turbocharger having an exhaust flow area changing means for changing an exhaust flow area to a turbine, and the exhaust recirculation device takes out exhaust gas from an upstream of the turbine. The control means controls the supercharging pressure and the fresh air amount to increase and decrease corresponding to each other with a change in the operating state. The control device for a supercharged engine according to any one of claims 1 to 5, wherein at least one of the exhaust flow area varying means and the opening amount of the exhaust gas recirculation valve is controlled. 7. An exhaust flow area changing means comprising a variable blade forming a nozzle whose opening degree can be changed with respect to a turbine of a turbocharger, wherein said control means controls said variable in an operating region in which exhaust gas recirculation is performed. The opening of the variable wing and the exhaust gas recirculation valve are controlled such that the supercharging pressure and the fresh air amount increase and decrease corresponding to each other as the operating state changes, while keeping the opening of the blade at a partial opening within a predetermined range. 7. The control device for a supercharged engine according to claim 6, wherein at least one of the quantity and the quantity is controlled. 8. The exhaust flow area varying means and the opening amount of the exhaust gas recirculation valve so that the change rate of the supercharging pressure with respect to the fresh air amount falls within a predetermined range in which the total turbo efficiency or the compressor efficiency is high. The control device for a supercharged engine according to claim 6 or 7, wherein at least one of the two is controlled. 9. The control device according to claim 1, wherein the control unit controls the exhaust flow area changing unit to increase the supercharging pressure when the ratio of the supercharging pressure increase to the increase in the fresh air amount is greater than or equal to a predetermined value. The control device for a supercharged engine according to any one of claims 6 to 8, wherein the control is performed in a direction to suppress a rise of the engine. 10. The control means according to claim 1, wherein the supercharging pressure and the fresh air amount to the engine increase and decrease in a predetermined engine speed range in which exhaust gas recirculation is performed from a low load range to a high load range. The control device for a supercharged engine according to any one of claims 6 to 9, wherein at least one of the exhaust flow area variable means and the opening amount of the exhaust gas recirculation valve is controlled. 11. The control device according to claim 6, wherein the control means gives priority to the opening amount of the exhaust gas recirculation valve.
The control device for a supercharged engine according to any one of the above. 12. The exhaust gas recirculation valve according to claim 6, wherein the control means controls both the exhaust gas flow area varying means and the opening amount of the exhaust gas recirculation valve at least on the low rotation speed side of the operating region where the exhaust gas recirculation is performed. 11. The control device for a supercharged engine according to any one of claims 10 to 10. 13. The control means preferentially controls the exhaust flow area variable means on the low rotation side of the operating region in which exhaust gas recirculation is performed, and gives priority to the opening amount of the exhaust gas recirculation valve on the high rotation side. The control device for a supercharged engine according to any one of claims 6 to 10, wherein the control is performed. 14. The supercharger according to claim 1, wherein the supercharger is a mechanical supercharger, and a supercharge amount is adjusted by a supercharge relief. Control device for engine with a charger. 15. A turbocharger having an exhaust flow area changing means for changing an exhaust flow area to a turbine, and taking out exhaust gas from an exhaust passage upstream of the turbine to obtain a turbocharger through an exhaust recirculation valve. An exhaust gas recirculation device that recirculates air to an intake passage downstream of the compressor, and has a means for controlling an exhaust gas recirculation valve so that an air-fuel ratio becomes a target air-fuel ratio. The exhaust flow area changing means and the exhaust gas recirculation so that the supercharging pressure and the fresh air amount to the engine increase and decrease corresponding to each other in accordance with a change in the operating state at least when the engine is accelerated in the operating region where the engine is accelerated. A control device for a supercharged engine, comprising: control means for controlling both opening amounts of a valve. 16. The control means is characterized in that, in an operating region where the exhaust gas recirculation valve opening amount is large, the supercharging pressure and the fresh air amount increase and decrease sufficiently in response to a change in the operating state. The exhaust gas flow area variable means and the exhaust gas recirculation valve opening amount are controlled so that the exhaust gas recirculation valve opening amount is reduced and the exhaust gas recirculation valve opening amount is reduced, and the exhaust gas flow area is varied so as to increase the exhaust gas flow area. 16. The control device for a supercharged engine according to claim 15, wherein the control unit controls the means. 17. The control means according to claim 1, wherein, when accelerating from a low engine speed region in which the exhaust gas recirculation valve opening is larger than in the other operation regions, the exhaust gas recirculation valve opening is reduced and the exhaust flow area is increased. The control device for a supercharged engine according to claim 15, wherein the control unit controls the exhaust flow area variable unit. 18. The exhaust control device according to claim 18, wherein the control means controls the exhaust flow area variable means so as to increase the exhaust flow area while reducing the exhaust gas recirculation valve opening amount during acceleration of the engine from a low rotation and low load range. The control device for a supercharged engine according to claim 15, wherein: 19. The supercharger according to claim 16, wherein said control means regulates the reduction of the exhaust gas recirculation valve opening amount during said acceleration to a predetermined lower limit value. Engine engine control device. 20. The apparatus according to claim 16, wherein said control means sets both the change amount of the exhaust gas recirculation valve opening amount and the change amount of the exhaust gas circulation area at the time of the acceleration to be larger as the engine speed decreases. Control device for supercharged engine. 21. The control device according to claim 16, wherein the ratio of the change amount of the opening of the exhaust gas recirculation valve to the change amount of the exhaust gas circulation area during the acceleration is set to be larger toward the lower engine speed. A control device for a supercharged engine according to any one of the preceding claims. 22. The control means according to claim 1, wherein, when accelerating at a relatively low engine speed, a change in the exhaust gas recirculation valve opening is prioritized. 17. The control device for a supercharged engine according to claim 16, wherein the control is given priority. 23. An intake air amount detecting means for detecting an amount of fresh air to the engine, and an actual fresh air amount detected by the intake air amount detecting means becomes a target fresh air amount obtained based on a target air-fuel ratio. 23. The control device for a supercharged engine according to claim 15, further comprising means for controlling the exhaust gas recirculation valve. 24. A supercharging pressure detecting means for detecting a supercharging pressure,
24. A device according to claim 15, further comprising: means for controlling the exhaust flow area varying means so that the actual supercharging pressure detected by the supercharging pressure detecting means becomes a preset target supercharging pressure. Control device for supercharged engine.