JP2000303896A - Control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent interference between an EGR feedback control and supercharging pressure feedback control, when both the EGR feedback control and supercharging pressure feedback control are employed. SOLUTION: Feedback control is applied to the opening of an EGR valve 24, so that actual air quantity detected with an air flowmeter 14 becomes the target air quantity. The feedback control is applied to the fluctuating position of a nozzle used for adjusting the exhaust gas inflow direction and provided in an exhaust turbo supercharger 15, so that actual supercharging pressure detected with an intake pressure sensor 17 becomes the target supercharging pressure. Establishment are employed, in such a way that the EGR feedback control is executed at the engine low-load region only, and the supercharging pressure feedback control is executed at the engine high-load region only. Their operating conditions are established so that both the feedback controls are not executed simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device.

[0002]

BACKGROUND OF THE INVENTION Modern engines, especially automotive di - in diesel engines, in order to significantly reduce the NO _X in the exhaust gas, it is desired to reflux a large amount of EGR gas to the engine intake system. To enable high EGR,
Japanese Unexamined Patent Publication No. Hei 8-193534 discloses that, among the intake passages,
An intake throttle valve is disposed upstream of the EGR gas inlet, and in an operation region where a large amount of EGR gas is required, the intake throttle valve is operated in the closing direction to reduce the effective opening area of the intake passage. It has been proposed to increase the negative pressure acting on the gas inlet to increase the suction effect of the EGR gas into the intake passage. When performing a large amount of EGR, the amount of air, that is, the amount of fresh air, and the amount of EGR gas are set to a predetermined ratio.
Feedback control of the EGR gas amount is also performed so that the actual air amount detected by the air amount detecting means becomes the target air amount.

On the other hand, in an engine, particularly a diesel engine for an automobile, supercharging is often performed to reduce unburned components such as HC, CO and smoke in exhaust gas and to secure output. Feedback control is also performed on the supercharging pressure, that is, the supercharging pressure adjusting means, so that the actual supercharging pressure becomes the target supercharging pressure.

[0004]

It is conceivable that both the feedback control for EGR and the feedback control for supercharging pressure are performed together. However, both fields
If the feedback control is performed simultaneously, the feedback controls interfere with each other, and it is difficult to quickly converge to the respective target values. That is, the EGR filter
Both feedback control and feedback control for boost pressure
The control causes a change in the intake air amount, but a change in the air amount caused by one of the feedback controls adversely affects the other feedback control.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent interference between feedback control for EGR and feedback control for supercharging pressure.
It is an object of the present invention to provide an engine control device which enables good feedback control.

[0006]

In order to achieve the above-mentioned object, the present invention adopts the following solution. That is, EGR gas amount adjusting means for adjusting the amount of EGR gas recirculated to the intake system of the engine, and air amount detection for detecting the amount of air supplied to the engine. Means, first feedback control means for performing feedback control on the EGR gas amount adjusting means so that the actual air amount detected by the air amount detecting means becomes the target air amount, and supercharging of the engine. A supercharging pressure adjusting unit that adjusts a pressure, a supercharging pressure detecting unit that detects a supercharging pressure, and the actual supercharging pressure detected by the supercharging pressure detecting unit is a target supercharging pressure. Second feedback control means for performing feedback control of the supercharging pressure adjusting means, wherein operating conditions of the first feedback control means and the second feedback control means are set to be different from each other. Ruko Accordingly, the both Fi - Dobakku control means is prevented from operating simultaneously, are so. Preferred embodiments on the premise of the above solution are as described in claim 2 and the following claims.

[0007]

According to the first aspect of the present invention, the operating conditions are set so that the first feedback control means and the second feedback control means do not operate simultaneously. Control can be performed satisfactorily. According to claim 2, the first Fi - while carefully NO _X reduction in the low load region under the control of Dobakku control means, in the high load region second Fi - target supercharging boost pressure by Dobakku control means Since the pressure can be made to match the pressure, it is possible to satisfy both the securing of the output in the high load region and the securing of the reliability of the engine. According to the third aspect, the boost pressure control is performed even in the low load region where the first feedback control means is operated to increase the amount of air, thereby ensuring output in the low load region and reducing unburned components. This is preferable for the purpose. Of course, since the boost pressure control is an open loop control, interference with the control by the first feedback control means does not matter. According to claim 4, NO _X reduction and an output secured, Di satisfies the reduction unburned components at a high level - diesel engine is provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes an engine,
In the embodiment, a multi-cylinder direct injection diesel engine for an automobile is used. That is, 2 is a cylinder block, 3 is a cylinder head, 4 is a piston, 5 is a fuel injection valve, 6 is a glow plug, 7 is an intake valve, 8 is an exhaust valve, and the fuel injection valve 5 directly injects fuel into the cylinder. Is set to do. Two intake valves 7 and two exhaust valves 8 are provided for each cylinder (FIG. 1 shows only one intake valve 7 and one exhaust valve 8).

The intake passage 10 is provided with a surge tank 11 on the way.
Having. The common intake passage 12 upstream of the surge tank 11 is used commonly for each cylinder, and sequentially from the upstream side to the downstream side, an air cleaner 13, an air flow meter 14 as an air amount detecting means, and an exhaust tank. A compressor wheel 15a of the turbocharger 15, an intercooler 16, an intake pressure sensor 17 as a supercharging pressure detecting means, and an intake throttle valve 18 as a first intake control valve to be described later. . Even when the intake throttle valve 18 is fully closed, the common intake passage 1
2, the common intake passage 12 is opened with a predetermined small effective opening area.

The surge tank 11 and each cylinder are independently connected by independent independent intake passages 19. The inside of the independent intake passage 19 is defined by a partition wall 19c as two parallel independent intake passages 19a and 19b, each of which is opened and closed by two intake valves 7. One branch independent intake passage 1
9a is opened in the combustion chamber so as to be directed substantially in the tangential direction of the cylinder so as to generate a swirl of the intake air in the combustion chamber. The other branch independent intake passage 19b has a second control valve as a second control valve. A swirl valve 20 is provided. Swirl
When the valve 20 is closed, the other branch independent intake passage 1
9b is completely closed, the intake air is supplied to the combustion chamber only from one of the branch independent intake passages 19a and the swirl is strengthened (the intake air flow is large).

In the exhaust passage 21 of the engine 1, a turbine wheel 15 b of an exhaust turbocharger 15 and an exhaust gas purifying catalyst (pre-catalyst) 22 are sequentially arranged from the upstream side to the downstream side.
Is disposed, and after the exhaust gas passes through the purification catalyst 22,
The exhaust gas is discharged to the atmosphere through another exhaust gas purification catalyst (main cater), not shown, and a silencer. Exhaust air
The wheels 15a and 15b of the turbocharger 15 are
It is connected so that it may rotate integrally via c. As described later, the turbocharger 15 has a variable supercharging capacity (supercharging efficiency).

A part of the exhaust gas in the exhaust passage 21 is EG
The air is returned to the common intake passage 12 through the R passage 23. The exhaust gas recirculation amount, that is, the EGR gas amount can be adjusted by an EGR valve 24 provided in the EGR passage 23 as EGR gas amount adjusting means. This EGR passage 23 is provided with respect to the exhaust passage 21.
An EGR gas inlet 23a is opened upstream of the turbine wheel 15b, and an EGR gas inlet 23b is opened to the common intake passage 12 between the intake throttle valve 18 and the surge tank 11. Note that cooling fins 25 for cooling the EGR gas over a predetermined length are formed on the outer periphery of the EGR passage 23 on a side closer to the exhaust passage 21 than the EGR valve 24.

The intake throttle valve 18 is driven to open and close by a negative pressure forward-acting actuator 31. Swirl valve 2
0 is driven to open and close by a negative pressure forward-acting actuator 32. The supercharging capability of the exhaust turbocharger 15 is changed by a negative pressure forward-acting actuator 33. Further, the EGR valve 24 is also of a negative pressure forward type.
EGR valve 24 and actuators 31 to 3
For the operation of 3, a vacuum pump 34 driven by the engine 1 is provided.

An actuator 31 is connected via a passage 36 to a negative pressure supply passage 35 which is always kept at a negative pressure by the vacuum pump 34, and an electromagnetic switching valve 37 is connected to the passage 36. Have been. This switching valve 37
Are turned on and off to supply a negative pressure to the actuator 31 (connected to the passage 35) to close the intake throttle valve 18, and to open the actuator 31 to the atmosphere. Then, the state is switched to a state in which the intake throttle valve 18 is opened.

The actuator 32 is connected to a negative pressure supply passage 35 through a passage 38, and an electromagnetic switching valve 39 is connected to the passage 38. This switching valve 39
Are turned on and off to supply a negative pressure to the actuator 32 (connected to the passage 35) to close the swirl valve 20, and to bring the actuator 32 to the atmosphere. The state is switched to a state in which the swirl valve 20 is opened by opening.

The actuator 33 is driven in a continuously variable manner, and is provided with a duty-controlled electromagnetic regulating valve 40. This regulating valve 40
Is a three-way valve, which is connected to the actuator 33 through a passage 41 and a negative pressure supply passage 35 through a passage 42.
To the air cleaner 13 via the passage 43.
Connected to an atmospheric pressure supply passage 44 extending from A negative pressure storage chamber 45 is connected to the passage 42. The degree of communication between the passage 41 (actuator 33) and the passage 43 (atmospheric pressure supply passage 44) of the passage 41 (actuator 33) and the passage 43 (atmospheric pressure supply passage 44) is changed by the adjusting valve 40 so as to be continuously variable. The supercharging capacity of the turbocharger 15 is changed to a continuously variable type. A bypass passage 46 is provided to bypass the regulating valve 40 and connect the passage 41 to the air supply passage 44, and an electromagnetic on-off valve 47 is connected to the bypass passage 46. Actuator 3
3 is operated so that the supercharging capacity becomes higher as the supplied negative pressure becomes larger. By opening the opening / closing valve 47, the supercharging capacity of the exhaust turbocharger 15 is responsively and at once. Be lowered.

For adjusting the opening degree of the EGR valve 24 as the EGR gas amount adjusting means, duty-type adjusting valves 50 and 51 are provided, respectively. The regulating valve 50 is a three-way valve, which is connected to (the negative pressure forward-acting actuator 24 a of) the EGR valve 24 via a passage 52, and connected to the negative pressure supply passage 35 via a passage 53. , And a passage 54 to the atmosphere supply passage 44. The other regulating valve 51 is connected to the passage 53. The degree of communication of the passage 52 (actuator 24a) with the passages 53 and 54 is changed to be continuously variable by the adjusting valve 50, and the magnitude of the negative pressure supplied to the adjusting valve 50 is continuously changed by the adjusting valve 51. Adjusted to the formula. The greater the negative pressure supplied to the actuator 24a, the greater the EGR valve 2
4 becomes large (the amount of EGR gas is large) and the regulating valve 5
By connecting the passage 52 only to the air supply passage 54 with 0, the EGR valve 24 is closed at once with good response.

FIG. 2 shows an example of a supercharging capacity adjusting portion of the exhaust turbocharger 15, that is, an example of supercharging pressure adjusting means. In FIG. 2, reference numeral 61 denotes a scroll portion, and a number of variable nozzles 62 are arranged around the turbine wheel 15b at equal intervals in the circumferential direction. Each variable nozzle 62
Are swingable about the rotation shaft 63, respectively, and change the direction in which the exhaust gas flows into the turbine wheel 15b. For example, when the variable nozzle 63 is at the position shown by the dashed line in FIG. 2, the exhaust gas hits the turbine wheel 15 b more vigorously and the supercharging capacity is larger than when it is at the position shown by the solid line in FIG. 2. Is done. Of course, the swing position of the variable nozzle 63 is changed by the actuator 33 described above. In order to change the supercharging capacity, an appropriate method such as a variable nozzle type as shown in FIG. 2 or a waste gate valve type can be used.

FIG. 3 shows an example of a control system. In the figure, U denotes a controller constituted by using a microcomputer. The controller U has a signal indicating the actual air amount from the air flow meter 14 described above,
In addition to the input of the signal indicating the intake pressure from the intake pressure sensor 17, the signal indicating the accelerator opening from the accelerator opening sensor (detecting means) S1, and the engine speed from the engine speed sensor (detecting means) S2 Is input. A predetermined control signal is output from the controller U to each of the aforementioned electromagnetic valves 37, 39, 40, 47, 50 and 51.

Next, an outline of control by the controller U will be described. First, in FIG. 3, the operating range of the engine is divided into four regions X1 to X4, using the engine speed and the fuel injection amount as the engine load as parameters. The regions X1, X2, X3, and X4 are arranged so that the rotation speed or the load becomes high in the order. The relationship between the open / close control of the intake throttle valve 18 and the swirl valve 20, the EGR control, and the supercharging pressure control with respect to the regions X1 to X4 is set as follows, for example.

(1) Intake throttle valve 18 and swirl valve 20 In the region X1, the intake throttle valve 18 and the swirl valve 20 are closed. In the regions X2 to X4, the respective valves 18 and 20 is opened. (2) EGR control In the regions X1 and X2, the opening of the EGR valve 24 is controlled so that the actual air amount detected by the air flow meter 14 becomes the target air amount. In the regions X3 and X4, the EGR is stopped (the EGR gas does not return to the intake passage). (3) Supercharging pressure control Although supercharging is performed in all regions X1 to X4, in region X4,
The supercharging capacity (the swing position of the variable nozzle 62) of the exhaust turbocharger 15 is feedback-controlled so that the actual supercharging pressure detected by the intake pressure sensor 17 becomes the target supercharging pressure. You. In the regions X1 to X3, supercharging can be performed without supercharging. However, supercharging is performed without supercharging pressure feedback control. It is preferable to control the supercharging pressure in an open-loop manner.

In the above-described feedback control of the EGR gas amount, if the deviation between the actual air amount and the target air amount is smaller than a predetermined value, the feedback correction value is not updated. A dead zone is set as shown in FIG. 5 (the state is a hold state in which the previous value is used as it is as the feedback correction value). The size of the dead zone (the size of the predetermined value) is changed based on parameters related to the magnitude of the intake pulsation, and the larger the intake pulsation, the larger the dead zone is set. In the embodiment, when the intake throttle valve 18 is opened (when the swirl valve 20 is opened), the dead zone is determined to be when the intake pulsation is greater than when the intake throttle valve 18 is closed. Changed to a larger value.

In FIG. 5 showing an example of setting a dead zone, the horizontal axis represents a deviation DAF obtained by subtracting a target air amount from an actual air amount.
S is set, and a duty control value for the adjustment valve 51 that indicates a feedback correction value (an opening correction value of the EGR valve 24) on the vertical axis is set. When the deviation DAFS is a positive value and large, the actual air amount is too large. In this case, the correction value (duty value) is increased (the direction in which the opening of the EGR valve 24 is increased). Correction). Conversely, when the deviation DAFS is a negative value and large, it is when the actual air amount is too small, and at this time, the correction value is decreased (the opening of the EGR valve 24 is decreased). When the deviation DAFS is so small as to fall within the dead zone shown in FIG. 5, the feedback correction value is not updated (the previous value remains).

The region X1 is a region in which an increase in the amount of EGR gas is required. Therefore, the intake throttle valve 18 is closed (the effective opening area of the intake passage 12 is minimum), and combustion is secured with the increase in the amount of EGR gas. As a result, the swirl valve 20 is closed to enhance the intake air flow. The target air amount is determined based on, for example, a map set in advance according to the fuel injection amount and the engine speed. When the intake throttle valve 18 is closed, the target air amount is reduced (small). Value). The reduction amount of the target air amount is the reduction amount of the actual air amount due to the closing of the intake throttle valve 18.
In other words, the maximum air amount that can flow through the intake passage 12 decreases as the opening degree of the intake throttle valve 18 decreases, but the maximum air amount that can be secured when the intake throttle valve 18 is fully opened and the intake throttle valve 18 The difference from the maximum air amount that can be secured at the time of the fully closed state is defined as a decrease in the target air amount.

In the feedback control of the supercharging pressure,
The swinging position of the nozzle 62 shown in FIG. 2 is controlled in accordance with the deviation between the actual supercharging pressure detected by the intake pressure sensor 17 and the target supercharging pressure. The target boost pressure can be set according to the operating state of the engine (for example, the engine speed and the fuel injection amount as the engine load). When the actual supercharging pressure becomes larger than the predetermined upper limit supercharging pressure, the regulating valve 47 is opened to protect the engine, and the supercharging pressure is immediately reduced. The feedback correction value is provided with upper and lower guard values, and the guard value is set, for example, according to the engine load (the larger the engine load, the larger the guard value is set).

In supercharging pressure control, regardless of whether the supercharging pressure feedback control is being executed or not being executed,
A base value (base duty value for the regulating valve 40) is set, and a feedback correction value is added to the base value, and an acceleration correction value and an atmospheric pressure correction value are also added to the base value. The final duty value for controlling the regulating valve 40 is calculated. Of course, when the feedback control of the supercharging pressure is not executed, the feedback correction value is set to zero.

Assuming the above, the controller U
6 will be described with reference to the flowcharts of FIG. 6 and the following, focusing on the feedback control of the EGR gas amount and the feedback control of the supercharging pressure.
In the following description, P, R, and Q indicate steps. First, in the main flowchart shown in FIG. 6, control for EGR is performed at P1 as described later, and control for supercharging pressure is performed at P2.

FIG. 7 shows details of the control for EGR, and corresponds to the contents of P1 in FIG. In FIG. 7, first, at Q1, data such as an accelerator opening, an engine speed, and an actual air amount are input. In Q2,
The fuel injection amount is calculated based on the accelerator opening and the engine speed. In Q3, it is determined whether or not the current operation state is a state in which the feedback control of the EGR gas amount is to be executed by comparing with a map as shown in FIG. 5 (regions X1 and X in FIG. 5). Or not). If the determination in Q3 is NO, in Q4, the intake throttle valve 18 and the swirl valve 20 are respectively opened and returned.

If the determination in Q3 is YES, it is determined in Q5 whether or not the current operation state is in the region X1. If the determination in Q5 is YES, in Q6,
The intake throttle valve 18 and the swirl valve 20 are closed. Thereafter, in Q7, the target air amount is determined based on the operating state of the engine (for example, the engine load and the engine speed) and the base value (for example, the fuel injection amount and the engine speed as described above). Is determined by subtracting the correction value (positive value) from the value. This correction value is for preventing the opening degree of the EGR valve 24 from becoming too small due to the fact that the actual air amount is greatly reduced by closing the intake throttle valve 18. (If the target air amount is left uncorrected, it is possible to prevent the EGR valve 24 from eventually closing to make the actual air amount the target air amount.) Then, in Q8, after the dead zone (see FIG. 5) is set to a small value set in advance, the process proceeds to Q12.

If the determination in Q5 is NO, in Q9, the intake throttle valve 18 and the swirl valve 20 are fully opened, respectively, and then, in Q10, the target air amount is determined according to the operating state of the engine. It is set as a base value (unlike Q7, there is no correction of the target air amount). Thereafter, in Q11, the dead zone is set to a preset large value, and then the process proceeds to Q12.

In Q12, a deviation DAFS obtained by subtracting the target air amount from the actual air amount is calculated. After this, Q1
At 3, it is determined whether or not the deviation DAFS is a large value that exceeds the range of the dead zone. If the determination in Q13 is YES, in Q14, as shown in FIG. 5, the feedback correction value is updated based on the deviation DAFS. If NO in Q13, the update of the feedback correction value is prohibited in Q15,
The feedback correction value is held at the previous value. After Q14 or Q15, respectively,
A feedback correction value (a duty value corresponding to the feedback correction value) is output.

FIG. 8 shows details of the supercharging pressure control.
This corresponds to the contents of P2 in FIG. In FIG. 8, first, at R1, data such as the accelerator opening, the engine speed, and the supercharging pressure are input, and then at R2, the actual supercharging pressure detected by the intake pressure sensor 17 exceeds a predetermined upper limit. It is determined whether the pressure is greater than the supply pressure. In this determination of R2, YE
In the case of S, the regulating valve 47 is opened at R3 in order to immediately reduce the supercharging pressure for protecting the engine.
If the determination in R2 is NO, the adjustment valve 47 is closed in R4.

After R4, it is determined in R5 whether or not the current EGR feedback control is performed in the region (FIG. 4).
Area X1, X2). This R
If the determination in step S5 is YES, the base duty value for the boost pressure adjusting valve 40 is set to EGR at R6.
A large value (a value in a direction in which the supercharging pressure increases) is set for operation (for execution). If the determination in R5 is NO, the base duty value is set to a small value in R7. The processing of R6 and R7 takes into account that the exhaust pressure is reduced when the EGR is performed as compared to when the EGR is not performed.
Compensation for the reduction of the supercharging pressure due to the decrease in the exhaust pressure when the GR is executed is lower than when the GR is not executed).

After R6 or R7, it is determined in R8 whether or not the current supercharging pressure is in the feedback control region (whether or not it is in the region X4 in FIG. 4). If the determination in R8 is YES, in R9, the feedback correction amount α is calculated based on the deviation between the actual supercharging pressure detected by the intake pressure sensor 17 and the target supercharging pressure. Next, at R10, an upper guard value (for increasing) and a lower guard value (for decreasing) of the feedback correction amount are set, respectively. Each guard value is set, for example, according to the engine load, and is set to be larger as the engine load is larger.

After Q10, it is determined in Q11 whether the feedback correction amount α is larger than the upper limit guard value. If the determination in R11 is YES, R12
At, the feedback correction amount α is set as the upper limit guard, and then the flow shifts to R16. If NO in R11, it is determined in R13 whether the feedback correction amount α is smaller than the lower limit guard value.
If the determination in R13 is YES, in R14,
After the feedback correction amount α is set as the lower limit guard value, the flow shifts to R16. If the determination in R13 is NO, the flow shifts to R16 without changing the feedback correction amount α based on the guard value.

At R16, an acceleration correction value and an atmospheric pressure correction value are calculated. The acceleration correction value is set such that the supercharging pressure increases as the degree of acceleration increases. The atmospheric pressure correction value is set so that the supercharging pressure becomes larger as the atmospheric pressure becomes smaller (lower). After R16, in R17, the feedback correction value α, the acceleration correction value, and the atmospheric pressure correction value are added to the above-described base duty value to calculate a final duty value. Then, at R18, the final duty value is output to the regulating valve 40. If the determination in R8 is NO, the feedback correction amount α is set to zero in R15,
The process proceeds to 16 (no feedback correction).

Although the embodiment has been described above, the present invention is not limited to this, and includes, for example, the following case. One or both of the intake throttle valve 18 and the swirl valve 20 may not be provided. Day
The present invention can be applied to engines other than the Zell engine and engines other than the direct injection type. In addition, the setting of the region in which the feedback control of the EGR gas amount is performed is not limited to the embodiment as long as the region in which the feedback control of the supercharging pressure is performed is set so as not to be simultaneously performed. You can do it. Also, this area setting
Instead of using both the engine load and the engine speed as parameters, for example, the area can be set only with the engine load or only the engine speed. As the supercharger, an appropriate type such as a type mechanically driven by an engine (a so-called supercharger) can be used.

Each step (step group) shown in the flowchart or various members such as a sensor and a switch can be expressed by adding a name of means to a higher-level expression of its function. Further, the steps (step group) shown in the flowchart can be expressed as a functional unit configured in the controller U (the feedback control means for the EGR gas amount is the controller U). Is understood as one functional unit). The objects of the present invention are not limited to those specified,
It implies to provide what is expressed as substantially preferred or advantageous. Further, the present invention can be expressed as a control method.

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a supercharging capacity changing portion of an exhaust turbocharger.

FIG. 3 is a control system diagram in the embodiment of FIG. 1;

FIG. 4 is a diagram showing an example of setting an area such as a feedback control area of an EGR gas amount;

FIG. 5 is a diagram showing an example of setting a dead zone for a feedback correction value.

FIG. 6 is a flowchart showing a control example of the present invention.

FIG. 7 is a flowchart showing a control example of the present invention.

FIG. 8 is a flowchart showing a control example of the present invention.

[Explanation of symbols]

 1: engine 10: intake passage 14: air flow meter (air amount detecting means) 15: exhaust turbocharger 17: intake pressure sensor (supercharging pressure detecting means) 21: exhaust passage 23: EGR passage 24 : EGR valve (EGR gas amount adjusting means) 33: Actuator (for supercharging pressure adjustment) 40: Adjusting valve (for supercharging pressure) 50, 51 Adjusting valve: (for EGR valve) 62: Nozzle (supercharging pressure adjustment) S1: Accelerator opening sensor S2: Engine speed sensor U: Controller (feedback control means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) F02D 21/08 301 F02D 21/08 301H 3G301 311B 311 41/02 301D 41/02 301 301E 380D 380 380E 41 / 18 Z 41/18 45/00 301A 45/00 301 F02M 25/07 570G F02M 25/07 570 570J F02B 37/12 301Q (72) Inventor Eiji Nakai No.3-1 Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation (72) Inventor Miyuki Matsumoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture F-term within Mazda Co., Ltd. CA07 DA08 EA05 ED08 GA00 GA01 GA04 GA14 GA15 GA21 3G071 AA10 AB06 BA 07 DA16 EA02 EA05 FA03 FA05 HA03 JA00 3G084 AA01 AA03 BA04 BA07 BA13 BA20 CA03 CA04 DA01 DA04 DA10 DA19 EA12 EB12 FA01 FA07 FA10 FA11 FA12 FA33 3G092 AA02 AA06 AA10 AA13 AA17 AA18 DB03 DC09 DC09 DG09 EA09 EC08 FA01 FA17 FA18 GA05 GA06 HA01Z HA05Z HA16X HA16Z HD07X HD07Z HE01Z HF08Z 3G301 HA01 HA02 HA06 HA13 JA01 JA25 JA26 KA08 KA09 LA00 MA11 NA08 NC02 ND03 ND07 NE01 NE06 NE17 NE20 NE25 PA01A PA01Z PA07Z PA09Z

Claims (4)

[Claims] 1. An EGR gas amount adjusting means for adjusting an EGR gas amount recirculated to an intake system of an engine; an air amount detecting means for detecting an air amount supplied to the engine; First feedback control means for performing feedback control on the EGR gas amount adjusting means so that the actual air amount becomes the target air amount, and supercharging pressure adjusting means for adjusting the supercharging pressure of the engine; A supercharging pressure detecting means for detecting a supercharging pressure; and a feedback control of the supercharging pressure adjusting means so that an actual supercharging pressure detected by the supercharging pressure detecting means becomes a target supercharging pressure. A second feedback control means, wherein the operating conditions of the first feedback control means and the second feedback control means are set to be different from each other, whereby both feedback control means are provided. Is the same It is not to operate, that the control device for an engine according to claim. 2. An engine according to claim 1, wherein operating conditions are set so that said first feedback control means is operated in a low load range of the engine, and said second feedback control means is provided with a high load of the engine. A control device for an engine, wherein operating conditions are set so as to be operated in a region. 3. The boost pressure adjusting means according to claim 2, wherein in a low load range in which the first feedback control means is operated, the boost pressure adjusting means is opened so that the boost pressure becomes a predetermined boost pressure. A control device for the engine, wherein 4. The engine control device according to claim 1, wherein the engine is a diesel engine.