JPH07269416A - Egr control device for fuel injection type engine - Google Patents

Abstract

PURPOSE:To improve exhaust gas emission by controlling an EGR valve, in the case that lamination combustion is selected in a low/medium load operation area, and even combustion is selected in a high load operation area, based on an engine speed and an engine load in the lamination combustion, and closing the EGR valve in the even combustion. CONSTITUTION:An EGR device is operated for circulating exhaust gas to an intake system through an EGR valve 14. A catalyst device 7 purifies exhaust gas. A first fuel injection valve 12 is arranged in a combustion chamber, while a second fuel injection valve 13 is arranged in an intake port in an engine 1. In an electronic control device based on an engine operation condition, lamination combustion is selected in a low/medium load operation area, while even combustion is selected in a high load operation area. When the lamination combustion is selected, an EGR ratio is set based on an engine speed and an engine load for controlling the EGR valve 14. When the even combustion is selected, the EGR valve 14 is closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a fuel injection engine in which a fuel injection valve is controlled on the basis of engine operating conditions to select between a stratified combustion system and a uniform combustion system. The present invention relates to an EGR control device for a fuel injection type engine, which greatly improves exhaust gas emission by controlling the operation of the.

[0002]

2. Description of the Related Art As a combustion method for an engine, a stratified combustion method in which a stratified rich mixture is ignited can make the overall air-fuel ratio lean, so that the fuel consumption can be significantly improved in the low and medium load operating range of the engine. Further, it is generally known in the past that the uniform combustion method of igniting a uniform mixture can improve the output in a high load operation region of the engine.

Therefore, various fuel injection engines have been proposed in the prior art in which the combustion system is switched between the stratified combustion system and the uniform combustion system depending on the load operation region of the engine. For example, in the low-medium-load operating region of the engine, the first fuel injection valve that directly injects high-pressure fuel into the combustion chamber in the latter stage of its compression stroke to perform stratified combustion, and in the high-load operating region of the engine Immediately before, there is provided a second fuel injection valve for injecting low-pressure fuel into the intake port for uniform combustion.

[0004]

By the way, the fuel injection type engine in which the combustion system is switched between the stratified combustion system and the uniform combustion system has the following problems in terms of exhaust gas purification measures. That is, in a normal three-way catalyst device, the NOx purification efficiency is significantly reduced in the lean operation region of the air-fuel ratio, so that the exhaust gas emission may be deteriorated during the stratified combustion in which the air-fuel ratio becomes lean.

As a measure for improving the exhaust gas emission during such stratified combustion, it is conceivable to use a lean NOx catalyst device together to purify NOx, but the NOx purification function is not sufficient at present. Is. In addition, JP-A-55-137348 and JP-A-55-1
As described in Japanese Patent No. 28636, it is conceivable to use an EGR device together to suppress the generation of NOx. However, the conventional EGR valve simply opens and closes the EGR passage by negative pressure control and has a responsiveness. Poorly, since the EGR amount cannot be finely controlled, the exhaust gas emission and the combustion state of the engine may not be maintained in a good state.

Therefore, the present invention significantly reduces exhaust gas emissions while maintaining a good engine combustion state from a low-medium load operating region of an engine in which stratified combustion is performed to a high-load operating region of an engine in which uniform combustion is performed. An object of the present invention is to provide an EGR control device for a fuel injection type engine that can be improved.

[0007]

To achieve this object, an EGR control device for a fuel injection engine according to the present invention as set forth in claim 1 has a variable flow rate E as shown in FIG.
E for recirculating exhaust gas to the intake system via the GR valve means 10
The engine includes a GR device and a catalyst device 7 installed in an exhaust system for purifying exhaust gas, and controls a fuel injection valve based on an engine operating state to select a stratified combustion method in an engine low / medium load operating range. In the fuel injection engine 1 that selects the uniform combustion method in the high load operation region, the selection means that selectively selects both combustion methods based on the engine speed and the engine load, and when the stratified combustion method is selected, EGR valve control means for setting the EGR rate based on the engine speed and engine load to control the EGR valve means and closing the EGR valve means when the uniform combustion method is selected. .

An EGR control system for a fuel injection engine according to the present invention as set forth in claim 2 is, as shown in FIG.
An EGR device that recirculates exhaust gas to the intake system via a variable flow rate EGR valve means 10 and a catalyst device 7 that is installed in the exhaust system to purify the exhaust gas are provided, and a fuel injection valve is set based on the engine operating state. In the fuel injection engine 1 in which the control is performed to select the stratified charge combustion method in the engine low / medium load operation area and the uniform combustion method in the engine high load operation area, the first fuel injection in which the high pressure fuel is directly injected into the combustion chamber The valve means 12, the second fuel injection valve means 13 for injecting low-pressure fuel into the intake system, the stratified charge combustion method is selected at the time of low and medium load of the engine based on the engine speed and the engine load, and the stratified charge combustion is performed at the intermediate load of the engine. Selecting means for selecting the two-zone combustion method by both uniform combustion and selecting the uniform combustion method when the engine has a high load,
When the stratified charge combustion method is selected, fuel is injected only from the first fuel injection valve means 12 in the latter stage of the compression stroke, and when the two zone combustion method is selected, the fuel injection amount is shared and the second fuel injection valve means 13 is shared. Fuel is injected immediately before the intake stroke from the first fuel injection valve means 12 and fuel is injected from the first fuel injection valve means 12 in the latter stage of the compression stroke, and only the second fuel injection valve means 13 is sucked when the uniform combustion method is selected. When the fuel injection control means for injecting fuel immediately before the stroke and the stratified combustion method and the two-zone combustion method are selected, the EGR rate is set based on the engine speed and the engine load to control the EGR valve means 10. EGR valve control means for closing the EGR valve means 10 when the uniform combustion method is selected is provided.

[0009]

In the EGR control system for the fuel injection type engine shown in FIG. 1, the selecting means selects the stratified charge combustion method in the engine low / medium load operating region and the engine high load operating region in the engine high load operating region based on the engine speed and the engine load. Select a uniform combustion method.

If the stratified charge combustion method is selected, the air-fuel ratio becomes lean and the NOx purification efficiency of the catalyst device is significantly reduced. However, at that time, the EGR valve control means sets the EGR rate based on the engine speed and the engine load, and
Since the R valve means is controlled, the exhaust gas is recirculated by the EGR device at a predetermined EGR rate during the stratified charge combustion.
N in the exhaust gas without deteriorating the combustion state of the engine
Generation of Ox is suppressed.

On the other hand, when the uniform combustion is selected, the air-fuel ratio becomes close to stoichio, and the catalyst device causes NOx in the exhaust gas.
To efficiently purify. At this time, the EGR valve control means closes the EGR valve means, so that the exhaust gas recirculation by the EGR device is stopped during uniform combustion, and the combustion state of the engine is maintained in a good condition.

Further, in the EGR control device for the fuel injection type engine shown in FIG. 2, the selecting means selects the stratified combustion system when the engine is low and medium load and the stratified combustion system when the engine is under intermediate load based on the engine speed and the engine load. The two-zone combustion system is selected by both the uniform combustion and the uniform combustion, and the uniform combustion system is selected when the engine has a high load.

When the stratified charge combustion system is selected, the fuel injection control means 10 directly injects the high pressure fuel into the combustion chamber only from the first fuel injection valve means in the latter stage of the compression stroke, so that the stratified charge combustion is performed. When the two-zone combustion method is selected, the fuel injection control means shares the fuel injection amount to inject low-pressure fuel into the intake system from the second fuel injection valve means immediately before the intake stroke, and at the latter stage of the compression stroke. By directly injecting high-pressure fuel from the first fuel injection valve means into the combustion chamber, two-zone combustion is achieved by both stratified combustion and uniform combustion.

Here, during the stratified charge combustion and the two-zone combustion, the air-fuel ratio becomes lean and the NOx purification efficiency of the catalyst device 7 remarkably decreases. At that time, the EGR valve control means is based on the engine speed and the engine load. Since the EGR rate is set and the EGR valve means is controlled, the exhaust gas is recirculated by the EGR device at a predetermined EGR rate during the stratified charge combustion and the two-zone combustion, without deteriorating the combustion state of the engine. Generation of NOx in the exhaust gas is suppressed.

On the other hand, when the uniform combustion is selected, the air-fuel ratio becomes close to stoichio, and the catalyst device causes NOx in the exhaust gas.
To efficiently purify. At this time, the EGR valve control means closes the EGR valve means, so that the exhaust gas recirculation by the EGR device is stopped during uniform combustion, and the combustion state of the engine is maintained in a good condition.

[0016]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 3 shows a schematic overall configuration of a fuel injection engine and its EGR control device according to one embodiment. An intake pipe 2 constituting an intake system of an engine 1 has an air cleaner 3, an air flow meter 4, and a throttle valve from the upstream side thereof. 5 is sequentially installed, and a three-way catalyst device 7 and a muffler 8 are sequentially installed in an exhaust pipe 6 that constitutes an exhaust system.

An EGR passage 9 is provided between a portion of the exhaust pipe 6 upstream of the three-way catalyst device 7 and a portion of the intake pipe 2 downstream of the throttle valve 5.
In the passage 9, a step motor drive type EGR valve 10 capable of continuously varying the passage cross-sectional area is provided as EGR valve means. If the EGR valve 10 has a high responsiveness of operation and can cope with a large flow rate,
Not only the step motor drive type but also various direct drive electronic control types such as duty solenoid drive type and linear solenoid drive type can be adopted.

The engine 1 includes a first injector 12 for directly injecting high pressure fuel into a combustion chamber in which an ignition plug 11 is installed, and a second injector 13 for injecting low pressure fuel into an intake port. And an electronic control unit 14 for controlling the fuel injection amount and the fuel injection timing of the first injector 12 and the second injector 13, respectively, and for controlling the operation of the EGR valve 10. . The engine 1 is further provided with a crank angle sensor 15 that detects the rotation angle of the crankshaft and outputs the detection signal to the electronic control unit 14.

The electronic control unit 14 includes a CPU, RO
An M, a RAM, an input port, an output port, and a timer are composed of a microcomputer interconnected via a bus line, and are connected to an A / D converter 14a and a waveform shaping circuit 14b connected to the input port, and an output port. The drive circuits 14c, 14d, 14e and the like are incorporated.

The intake air amount signal Q from the air flow meter 4 is input to the A / D converter 14a, and the crank angle signal θ from the crank angle sensor 15 is input to the waveform shaping circuit 14b. Also, the drive circuit 1
A predetermined fuel injection control signal Ti ₁ is output to the first injector 12 via 4c, and a predetermined fuel injection control signal T ₁ is output to the second injector 13 via a drive circuit 14d.
i ₂ is output, and the opening control signal α is output to the EGR valve 10 via the drive circuit 14e.

FIG. 4 is a block diagram showing a part of the function of the electronic control unit 14, which is a combustion system selecting means 14f as a selecting means, and a stratified combustion fuel injection controlling means 14g as a fuel injection controlling means. Two-zone combustion fuel injection control means 14h, uniform combustion fuel injection control means 14i,
EGR valve opening / closing control means 1 as EGR valve control means
4j are configured.

The combustion system selecting means 14f receives the intake air amount signal Q from the air flow meter 4 via the A / D converter 14a and the crank angle signal θ from the crank angle sensor 15 via the waveform shaping circuit 14b. Calculate the engine speed N and engine load based on
By using the engine speed N and the engine load as parameters, a stratified combustion method is used in the engine low / medium load operating area, a uniform combustion method is used in the engine high load operating area, and a low / medium load operating area and a high engine operating area are set according to the combustion method map shown in FIG. The two-zone combustion method is selected in the engine intermediate load operating range between the two and the load operating range.

The combustion mode selection means 14f is a fuel injection control means corresponding to the selected combustion method, that is, a stratified combustion fuel injection control means 14g, a two-zone combustion fuel injection control means 14h, and a uniform combustion fuel injection control. When outputting the intake air amount signal Q and the engine speed signal N input to any of the means 14i, and also to the stratified charge fuel injection control means 14g or the two-zone combustion fuel injection control means 14h. Outputs the intake air amount signal Q and the engine speed signal N to the EGR valve opening / closing control means 14j, and when outputting them to the uniform combustion fuel injection control means 14i, the intake air amount signal Q to the EGR valve opening / closing control means 14j. And the output of the engine speed signal N is stopped.

Here, the fuel injection control means 14 for stratified charge combustion
The g is a map search of the basic fuel injection amount of the first injector 12 using the input intake air amount signal Q and the input engine speed signal N as parameters, and based on the pattern A shown in the fuel injection timing chart of FIG. The fuel injection control signal Ti ₁ is output to the drive circuit 14c of the first injector 12 at the latter stage of the compression stroke immediately before ignition.

Further, fuel injection control means 14i for uniform combustion
Is the input intake air amount signal Q and engine speed signal N
Using as a parameter, the basic fuel injection amount of the second injector 13 is searched for a map, and the fuel injection control signal Ti _{2 is set} to the second injector 1 immediately before the intake stroke based on the pattern C shown in the fuel injection timing chart of FIG.
3 to the drive circuit 14d.

Further, the two-zone combustion fuel injection control means 14h uses the input intake air amount signal Q and the input engine speed signal N as parameters to determine the basic fuel injection amount shared by the first injector 12 and the second injector 13. While searching the respective maps, based on the pattern B shown in the fuel injection timing chart of FIG. 6, the fuel injection control signal Ti ₂ is output to the drive circuit 14d of the second injector 13 immediately before the intake stroke, and immediately after ignition. The fuel injection control signal Ti ₁ is output to the drive circuit 14c of the first injector 12 in the latter half of a certain compression stroke.

Here, the EGR valve opening / closing control means 1
4j is an intake air amount signal Q from the combustion system selection means 14f.
And the engine speed signal N, the opening degree α of the EGR valve 14 is calculated based on the intake air amount signal Q and the engine speed signal N so that the EGR rate is set to 20%. The degree control signal α to the drive circuit 14e of the EGR valve 14 and the intake air amount signal Q and the engine speed signal N are not input,
OFF to close the EGR valve 10 and set its opening to zero
The signal is output to the drive circuit 14e. Although the EGR rate is set to 20% in this embodiment, the EGR rate is not limited to 20% and can be set to another value as appropriate.

Next, the operation of the embodiment of the EGR control device for the fuel injection type engine constructed as described above will be described with reference to the flow charts of FIGS. During operation of the engine 1, the combustion system selection means 14f of the electronic control unit 14 inputs the intake air amount signal Q and the crank angle signal θ as described above (step 1), and based on these input signals Q, θ, the engine The engine speed N and the engine load are calculated (step 2). Then, using the calculated engine speed N and engine load as parameters, a stratified combustion method is used in the engine low and medium load operating range, a uniform combustion method is used in the engine high load operating range, and a low and medium load operating range according to the combustion mode map shown in FIG. The two-zone combustion method is selected in the engine intermediate load operating range between the high load operating range and the high load operating range (step 3).

In the following step 4, it is judged whether the selected combustion system is the stratified combustion system, the two-zone combustion system or the uniform combustion system. When the determination result is the stratified charge combustion method, the pattern A shown in the fuel injection timing chart of FIG. 6 is selected (step 5) and the flag F is set to 1 (step 6). Then, the stratified charge fuel injection control means 14g sends the fuel injection control signal Ti ₁ to the first injector 12 at the latter stage of the compression stroke immediately before ignition.
By performing the output to the drive circuit 14c, the stratified charge combustion is performed in the engine low and medium load operation region.

When the determination result of the step 4 is the two-zone combustion system, the pattern B shown in the fuel injection timing chart of FIG. 6 is selected (step 7) and the flag F is set to 2 (step). 8). Then, the two-zone combustion fuel injection control means 14h outputs the fuel injection control signal Ti ₂ to the drive circuit 14d of the second injector 13 immediately before the intake stroke, and then the fuel injection control signal at the latter stage of the compression stroke immediately before ignition. Ti ₁ is the first injector 12
In the engine intermediate load operating region between the low and medium load operating regions and the high load operating region, the two-zone combustion by both stratified combustion and uniform combustion is performed by outputting to the drive circuit 14c.

If the result of the determination in step 4 is the uniform combustion system, pattern C shown in the fuel injection timing chart of FIG. 6 is selected (step 9).
The flag F is set to 3 (step 10). Then, the uniform combustion fuel injection control means 14i outputs the fuel injection control signal Ti ₂ to the drive circuit 14d of the second injector 13 immediately before the intake stroke, so that uniform combustion is performed in the engine high load operation region.

Subsequently, it is determined whether or not the flag F = 3 to determine whether or not the current combustion system of the engine 1 is the uniform combustion system (step 11), and the determination result is YE.
If it is S, the EGR valve opening / closing control means 14j closes the EGR valve 10 and outputs an OFF signal to zero the opening thereof to the drive circuit 14e (step 12). On the other hand, if the determination result is NO, the EGR valve opening / closing control means 14j
Calculates the opening α of the EGR valve 10 based on the intake air amount signal Q and the engine speed signal N so as to set the EGR rate to 20% (step 13), and subsequently, the opening control signal α as the calculation result. Drive circuit 14 for EGR valve 10
It is output to e (step 14).

That is, according to this embodiment, the air-fuel ratio becomes lean when the stratified charge combustion is performed in the low and medium load operation region of the engine 1 and the two-zone combustion is performed in the intermediate load operation region. In order to eliminate the inconvenience that the NOx purification efficiency of the three-way catalyst device 7 significantly decreases, the EGR valve 1
An opening control signal α for setting the EGR rate to 20% is output to 0. The step motor drive type EGR valve 10 that receives the opening control signal α opens the EGR passage 9 to the opening α with good responsiveness to recirculate the exhaust gas to the intake system. Generation of NOx in the exhaust gas is suppressed without deteriorating.

On the other hand, when uniform combustion is performed in the high load operation region of the engine 1, the air-fuel ratio is near stoichio and the three-way catalyst device 7 can efficiently purify NOx in the exhaust gas. An OFF signal for closing the EGR passage 9 with the opening thereof set to zero is output to the valve 10. Therefore, the step motor drive type EGR valve 10 fully closes the EGR passage 9 with good responsiveness to stop the recirculation of the exhaust gas to the intake system, so that the combustion state of the engine 1 is maintained well.

The present invention is not limited to the embodiment described above, but includes only the first injector 12 for directly injecting high pressure fuel into the combustion chamber as the fuel injection valve means, and the engine is operated at low and medium loads. The present invention can also be applied to a fuel injection type engine in which fuel is injected and stratified combustion in the latter part of the compression stroke in the region, and fuel is injected and homogeneously burned in the engine high load operation region from the beginning of the intake stroke. Further, the tumble control valve is provided with the second injector 13 for injecting fuel into the intake system such as the intake port and the tumble control valve, and the fuel injected from the second injector is generated by the tumble control valve in the intake stroke in the low and medium load operation region of the engine. The stratified combustion is performed by being surrounded by the tumble flow in the cylinder, and in the high load operation region of the engine, the generation of the tumble flow is stopped and fuel is injected from the second injector 13 immediately before the intake stroke to perform uniform combustion. It is also applicable to the fuel injection type engine.

[0036]

As described above, according to the first aspect of the invention, when stratified charge combustion is selected by the selecting means in the engine low / medium load operating region, the EGR valve control means is based on the engine speed and the engine load. Set the rate and EG
Since the R valve means is controlled, the exhaust gas is recirculated by the EGR device at a predetermined EGR rate during the stratified combustion,
N in the exhaust gas without deteriorating the combustion state of the engine
Generation of Ox is suppressed.

On the other hand, when the selection means selects uniform combustion in the engine high load operation region, the air-fuel ratio becomes close to stoichio, whereby the catalyst device efficiently purifies NOx in the exhaust gas. At this time, since the EGR valve control means closes the EGR valve means, the exhaust gas recirculation by the EGR device is stopped during uniform combustion, and the combustion state of the engine is maintained in a good condition.

Therefore, according to the first aspect of the present invention, from the low and medium load operating range of the engine in which stratified charge combustion is performed to the high load operating range of the engine in which uniform combustion is performed,
Exhaust gas emissions can be significantly improved while maintaining a good engine combustion state.

According to the second aspect of the present invention, the stratified charge combustion method is selected by the selecting means when the engine is low and medium load, and the stratified charge combustion is performed by the fuel injection control means, or the two zone combustion is performed by the selecting means when the engine is under intermediate load. When the system is selected and the two-zone combustion is performed by the fuel injection control means, the EGR valve control means sets the EGR rate based on the engine speed and the engine load to control the EGR valve means. During the zone combustion, the exhaust gas is recirculated by the EGR device at a predetermined EGR rate, and the generation of NOx in the exhaust gas is suppressed without deteriorating the combustion state of the engine.

On the other hand, when the uniform combustion method is selected by the selecting means at the time of high engine load and uniform combustion is performed by the fuel injection control means, the air-fuel ratio becomes close to stoichio, so that the catalyst device efficiently reduces NOx in the exhaust gas. Purify well. At this time, since the EGR valve control means closes the EGR valve means, the exhaust gas recirculation by the EGR device is stopped during uniform combustion, and the combustion state of the engine is maintained in a good condition.

Therefore, also according to the invention described in claim 2,
Exhaust gas emissions can be significantly improved while maintaining a good combustion state of the engine from a low-medium-load operating region of the engine in which stratified combustion is performed to a high-load operating region of the engine in which uniform combustion is performed.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of the invention according to claim 1.

FIG. 2 is a claim correspondence diagram showing the configuration of the invention according to claim 2;

FIG. 3 is an overall schematic configuration diagram of an embodiment.

FIG. 4 is a functional block diagram of an electronic control device that is a main part of one embodiment.

FIG. 5 is a combustion method map used in one embodiment.

FIG. 6 is a fuel injection timing timing chart used in one embodiment.

FIG. 7 is a flowchart showing the operation of the embodiment.

FIG. 8 is a flowchart showing the operation of one embodiment.

[Explanation of symbols]

 1 Engine 2 Intake Pipe 3 Air Cleaner 4 Air Flow Meter 5 Throttle Valve 6 Exhaust Pipe 7 Three-Way Catalyst Device (Catalyst Device) 8 Muffler 9 EGR Passage 10 EGR Valve (EGR Valve Means) 11 Spark Plug 12 First Injector (First Fuel) Injection valve means) 13 second injector (second fuel injection valve means) 14 electronic control unit 14a A / D converter 14b waveform shaping circuit 14c, 14d, 14e drive circuit 14f combustion mode selection means 14g fuel injection control means for stratified combustion 14h Two-zone combustion fuel injection control means 14i Uniform combustion fuel injection control means 14j EGR valve opening / closing control means 15 Crank angle sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02D 41/34 C 9247-3G F02M 63/00 P

Claims (2)

[Claims] 1. An EGR device that recirculates exhaust gas to an intake system through a variable flow rate EGR valve means, and a catalyst device that is installed in the exhaust system to purify the exhaust gas, and
In the fuel injection engine, the fuel injection valve is controlled based on the engine operating condition to select the stratified combustion method in the engine low and medium load operating range and the uniform combustion method in the engine high load operating range. When the stratified charge combustion method is selected, the EGR rate is set based on the engine speed and the engine load, and the EGR rate is set based on the engine speed and the engine load.
When the valve means is controlled and the uniform combustion method is selected,
An EGR control device for a fuel injection engine, comprising: EGR valve control means for closing the EGR valve means. 2. An EGR device that recirculates exhaust gas to an intake system via a variable flow rate EGR valve means, and a catalyst device that is installed in the exhaust system to purify the exhaust gas,
In a fuel-injection engine that controls the fuel injection valve based on the engine operating condition to select the stratified combustion method in the engine low and medium load operating range, and to select the uniform combustion method in the engine high load operating range, high pressure fuel is supplied to the combustion chamber. First fuel injection valve means for direct injection, second fuel injection valve means for injecting low-pressure fuel into the intake system, and stratified charge combustion method is selected based on engine speed and engine load when the engine is at low and medium loads. At the time of intermediate load, the two-zone combustion method by both stratified combustion and uniform combustion is selected, and at the time of high engine load, selection means for selecting the uniform combustion method, and when stratified combustion method is selected, at the latter stage of the compression stroke, The fuel is injected only from the fuel injection valve means, and when the two-zone combustion system is selected, the fuel injection amount is shared and the fuel is injected from the second fuel injection valve means. The fuel is injected immediately before the air stroke, and the fuel is injected from the first fuel injection valve means in the latter stage of the compression stroke, and when the uniform combustion system is selected, only from the second fuel injection valve means immediately before the intake stroke. When the fuel injection control means for injecting fuel and the stratified combustion method and the two-zone combustion method are selected, the EGR rate is set based on the engine speed and the engine load to control the EGR valve means, and the uniform combustion method is set. When selected, EG for closing the EGR valve means
An EGR control device for a fuel injection type engine, comprising: R valve control means.