JPH07293260A - Swirl controller for fuel injection type engine - Google Patents

Abstract

PURPOSE:To improve emission, improve fuel consumption and output by selecting the laminar combustion or uniform combustion on the basis of the operation state of an engine and opening/closing-controlling a swirl valve so that the specific condition on the basis of the selection is satisfied. CONSTITUTION:In the intake passage 2 of an engine 1, a swirl valve 10 which generates a swirl flow inside a cylinder when a valve is closed is arranged. Since a plurality of fuel injection valves 11 and 12 are controlled on the basis of the engine operation state, the laminary ocmbustion and the uniform combustion are realized. In this case, in each combustion system of the laminary combustion or unifiorm combustion is selected by a selecting means on the basis of the engine revolution speed or the engine load. In case of the selection of the laminary ocmbustion, etc., the swirl valve 10 is closed, while if the uhiform vombustion is selected in the high load operation region in the vicinity of the perfect throttle opening, control is performed by the swirl valve control means so that the swirl valve 10 is opened.

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 type engine in which a combustion system is switched between at least a stratified combustion system and a uniform combustion system by controlling a fuel injection valve based on an operating state of the engine. The present invention relates to a swirl control device for a combustion injection engine, which improves a combustion state by controlling flow generation.

[0002]

2. Description of the Related Art In a stratified combustion system in which a stratified rich mixture is ignited as an engine combustion system, the overall air-fuel ratio can be made lean so that the fuel consumption can be improved in the low and medium load operating range of the engine, while the uniform combustion can be achieved. It is generally known in the past that the uniform combustion system in which the air-fuel mixture is ignited can improve the output in a high load operation region of the engine. Further, even in the same stratified combustion method, in the method of directly injecting fuel into the combustion chamber using the in-cylinder injector, the lean limit of the air-fuel ratio can be significantly improved compared to the method of injecting fuel into the intake port. As a result, it has been generally known that fuel efficiency can be significantly improved.

Therefore, as disclosed in Japanese Patent Laid-Open No. 62-248819, the fuel spray from the in-cylinder injector is placed on the air flow passing through the center of the swirl flow to form a strong stratified mixture. Fuel injection type engine, and as described in JP-A-60-30416,
In-cylinder injection injector and intake pipe injection injector are used together, and in the low-load region of the engine, stratified charge combustion is performed by injecting fuel from the in-cylinder injector to the vicinity of the spark plug in the center of the combustion chamber, and the high-load region of the engine There is also known a fuel injection engine in which fuel is injected from an intake pipe injection injector into the intake pipe for uniform combustion.

[0004]

By the way, in the fuel injection type engine disclosed in Japanese Patent Laid-Open No. 62-248818, the in-cylinder injector injects fuel obliquely from the side of the combustion chamber toward the center. Therefore, the injected fuel spray crosses the swirl flow, and a part of the fuel spray diffuses along the swirl flow. Therefore, it is expected that the stratified charge combustion becomes unstable and the generation of HC increases.
In addition, since the in-cylinder injector is installed obliquely on the side of the combustion chamber, if the fuel injection amount changes according to the fluctuation of the engine load, the deployed position of the injected fuel will change from the center of the combustion chamber. There is also a problem that it is difficult to generate a good stratified air-fuel mixture that is predicted to come off and that corresponds to a change in engine load.

On the other hand, in the fuel injection engine described in the above-mentioned Japanese Patent Laid-Open No. 60-30416, the in-cylinder injector injects the fuel laterally from the side of the combustion chamber toward the vicinity of the spark plug in the center of the combustion chamber. Because it is installed as
It is difficult to generate a rich mixture near the spark plug during stratified combustion in the low load region, and it is predicted that stable stratified combustion will be difficult to obtain.

Even in a fuel injection type engine in which the combustion mode is switched between stratified charge combustion and uniform combustion in this way, it is generally difficult to carry out stable and good stratified charge combustion, and emission is further improved, and fuel consumption and output are improved. There is a demand for further improvement.

Therefore, the present invention provides a swirl control device for a fuel injection type engine, which is capable of achieving both stable and favorable stratified combustion and uniform combustion to further improve emissions comprehensively and to further improve fuel efficiency and output. The purpose is to provide.

[0008]

In order to achieve this object, a swirl control device for a fuel injection type engine according to the present invention as set forth in claim 1 is an engine 1 as shown in FIG.
The intake passage 2 is provided with a swirl valve 10 that is controlled to open and close to generate a swirl flow in the cylinder when the intake passage 2 is closed, and the fuel injection valve is controlled based on the engine operating state to stratify in an engine low / medium load operating region. In a fuel-injection engine that burns and burns uniformly in a high engine load operating region, a selection unit that selectively selects each of the above-described stratified combustion or homogeneous combustion combustion systems based on the engine speed and engine load, and a stratified combustion system Is selected and when the uniform combustion method is selected in the high load operating range except near the throttle fully opening, the swirl valve 10 is controlled to be closed. When the uniform combustion method is selected in the high load operating range near the throttle fully opening, the swirl valve 10 is selected. A swirl valve opening / closing control means for controlling the opening is provided.

A swirl control device for a fuel injection engine according to a second aspect of the present invention, as shown in FIG. In a fuel injection engine that includes a swirl valve 10 that generates a swirl flow, controls the fuel injection valve based on the engine operating state, and performs stratified combustion in an engine low / medium load operating region and uniformly burns in an engine high load operating region, First fuel injection valve means 11 for directly injecting high-pressure fuel from the center of the combustion chamber 1a toward the center of the cylinder bore, second fuel injection valve means 12 for injecting low-pressure fuel into the intake system, and engine speed. Based on the engine load and the engine load, the stratified charge combustion method is selected when the engine load is low. With selecting over emissions combustion method,
The fuel is injected only from the first fuel injection valve means 11 when the uniform combustion method is selected when the engine is under high load, and the first fuel injection valve means 11 is selected when the stratified combustion method is selected, and the fuel injection amount is shared when the two-zone combustion method is selected. Fuel is injected from the second fuel injection valve means 12 and fuel is injected from the first fuel injection valve means 11, and fuel is injected only from the second fuel injection valve means 12 when the uniform combustion system is selected. When selecting the fuel injection control means and the stratified charge combustion method, 2
When the zone combustion method is selected and when the uniform combustion method is selected in the high load operating range except near the throttle full opening, the swirl valve 10 is closed and the uniform combustion method is selected in the high load operating range near the throttle fully opening. A swirl valve opening / closing control means for controlling the opening of the swirl valve 10 is provided.

The invention described in claim 3 is the same as that of claim 2.
The fuel injection control means in the invention described in (1) above sets the fuel injection timing from the first fuel injection valve means to the latter stage of the compression stroke,
The fuel injection timing from the second fuel injection valve means is set immediately before the intake stroke.

[0011]

In the swirl control device for a fuel injection type engine according to claims 1 and 2, when the stratified charge combustion method is selected by the selection means in the engine low and medium load operation region, stratified charge combustion is performed by the control of the fuel injection valve, At that time, the swirl valve opening / closing control means controls the swirl valve 10 to close. For this reason,
A swirl flow is generated in the cylinder during the intake stroke, and this swirl flow does not easily inadvertently spread around the fuel spray for stratified combustion that has been injected from the fuel injection valve, and it is stable and good stratification Burning takes place.

Further, when the uniform combustion method is selected by the selecting means in the engine high load operating region, the fuel is injected uniformly by controlling the fuel injection valve. At that time, the engine load operating region is compared with the load except the vicinity of the fully opened throttle. If the region is relatively light, the swirl valve opening / closing control means closes the swirl valve 10. Therefore, a swirl flow of a homogeneous air-fuel mixture is generated in the cylinder during the intake stroke, and this swirl flow is converted into turbulent components in the latter part of the compression stroke, resulting in good uniform combustion accompanied by turbulent combustion with a high combustion speed. And combustion is promoted.

In the swirl control device for a fuel injection type engine according to a second aspect of the invention, the swirl valve opening / closing control means is used even when the two-zone combustion method is selected by the selection means at the time of engine intermediate load and the two-zone combustion is performed. Controls the swirl valve 10 to close. For this reason, a swirl flow of a homogeneous mixture is generated in the cylinder during the intake stroke, and this swirl flow surrounds the fuel spray for stratified combustion injected from the fuel injection valve and prevents inadvertent diffusion. By that,
Uniform combustion with good stratified combustion takes place. Further, the swirl flow of the generated homogeneous air-fuel mixture is converted into a turbulent component in the latter part of the compression stroke, and turbulent combustion with a high burning velocity is accompanied, whereby combustion is promoted.

On the other hand, in the case of uniform combustion in the engine high load operating region, if the engine load operating region is in the region near the throttle fully opening, the swirl valve opening / closing control means controls the swirl valve 10 to open. For this reason, a sufficient amount of intake air is ensured and a swirl flow is not generated in the cylinder, and as a result, the combustion speed is excessively increased due to conversion of the swirl flow into a turbulent component, and knocking occurs. It is avoided and good homogeneous combustion is achieved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 2 shows an overall schematic configuration of a fuel injection type engine and its swirl control device according to one embodiment. An intake pipe 2 constituting an intake system of an engine 1 includes an air cleaner 3, an air flow meter 4, and a throttle valve from the upstream side thereof. 5 are sequentially installed, and a catalytic converter 7 and a muffler 8 are sequentially installed in an exhaust pipe 6 that constitutes an exhaust system.

Here, as shown in FIG. 3, the engine 1
Is a 4-valve structure having a Siamese type intake port and an exhaust port. A branch passage on one side of the intake port forms a main port 1b, and a branch passage on the opposite side communicates with a peripheral portion of the combustion chamber 1a by a partition wall 9. It is divided into a swirl port 1c and a subport 1d that communicates with the vicinity of the center of the combustion chamber 1a. And above swirl port 1
A swirl valve 10 that opens and closes the sub port 1d and the main port 1b at the same time with c always open is installed in the suction pipe 2 at the front end of the partition wall 9.

The engine 1 is an in-cylinder injector 11 installed at the central top of the combustion chamber 1a for directly injecting high pressure fuel toward the center of the cylinder bore, and a port for injecting low pressure fuel into the main port 1b of the intake port. The injection injector 12 is provided as the first and second fuel injection valve means, and the fuel injection amount and the fuel injection timing of the in-cylinder injection injector 11 and the port injection injector 12 are respectively controlled, and the swirl valve 10 is opened and closed. The electronic control unit 13 for controlling A crank angle sensor 14 that detects the rotation angle of the crankshaft and outputs the detection signal to the electronic control unit 13 is attached to the engine 1. Although not shown, the spark plug is installed so that the plug gap at its tip faces the combustion chamber 1a which is in front of the in-cylinder injector 11 in the fuel injection direction.

The electronic control unit 13 includes a CPU, RO
An M / 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 13a and a waveform shaping circuit 13b connected to the input port, and an output port. The drive circuits 13c, 13d, 13e and the like are incorporated.

The intake air amount signal Q from the air flow meter 4 is input to the A / D converter 13a, and the crank angle signal θ from the crank angle sensor 14 is input to the waveform shaping circuit 13b. Also, the drive circuit 1
A predetermined fuel injection control signal Ti ₁ is output to the in-cylinder injector 11 via 3c, and a predetermined fuel injection control signal Ti ₂ is output to the port injection injector 12 via a drive circuit 13d. The open / close control signals ON and O are sent to the swirl valve 10 via the circuit 13e.
FF is output.

FIG. 4 is a block diagram showing a part of the function of the electronic control unit 13, which is a combustion system selecting means 13f as a selecting means and a stratified combustion fuel injection controlling means 13g as a fuel injection controlling means. Fuel injection control means 13h for two-zone combustion, fuel injection control means 13i for uniform combustion
And a swirl valve opening / closing control means 13j.

The combustion system selecting means 13f receives the intake air amount signal Q input from the air flow meter 4 via the A / D converter 13a and the crank angle signal θ input from the crank angle sensor 14 via the waveform shaping circuit 13b. Calculate the engine speed N and engine load based on
Using the engine speed N and the engine load as parameters, four combustion methods, that is, a stratified charge combustion method in the low and medium load operation region of the engine 1, are selected from the combustion method map shown in FIG.
In the high load operation range, the first uniform combustion method is used in the area where the load is relatively light except near the throttle full opening, and the second uniform combustion method is used in the high load operation area near the throttle fully opening. In the engine intermediate load operating range between the range and the high load operating range, the two-zone combustion system is selected, and the selection signal M is output to the swirl valve opening / closing control means 13j described later.

When the stratified charge combustion method is selected, the combustion mode selection means 13f selects the stratified charge fuel injection control means 13.
If the two-zone combustion system is selected for g, the two-zone combustion fuel injection control means 13h will display the first uniform combustion system or the second uniform combustion system.
When the uniform combustion method is selected, the intake air amount signal Q and the engine speed signal N are output to the uniform combustion fuel injection control means 13i, respectively.

Here, the fuel injection control means 13g for stratified charge combustion
Is the input intake air amount signal Q and engine speed signal N
And the basic fuel injection amount of the in-cylinder injector 11 as a parameter, and based on the pattern A shown in the fuel injection timing chart of FIG. 6, the fuel injection control signal Ti ₁ is output in the latter half of the compression stroke immediately before ignition. Is output to the drive circuit 13c of the in-cylinder injector 11.

Further, the uniform injection fuel injection control means 13i
Is the input intake air amount signal Q and engine speed signal N
With the parameters and as parameters, the basic fuel injection amount of the port injection injector 12 is searched for a map, and the fuel injection control signal Ti _{2 is set} to the port injection injector 12 immediately before the intake stroke based on the pattern C shown in the fuel injection timing chart of FIG. Output to the drive circuit 13d.

Further, the two-zone combustion fuel injection control means 13h uses the input intake air amount signal Q and engine speed signal N as parameters to in-cylinder injector 11.
And the basic fuel injection amount shared by the port injection injector 12 is searched for on a map, and based on the pattern B shown in the fuel injection timing chart of FIG. 6, the fuel injection control signal Ti ₂ is sent to the port injection injector 12 immediately before the intake stroke. The fuel injection control signal Ti ₁ is output to the drive circuit 13c of the in-cylinder injector 11 at the latter stage of the compression stroke immediately before ignition.

Here, the swirl valve opening / closing control means 13j responds to the combustion system selection signal M inputted from the combustion system selection means 13f, which is a stratified combustion system, a two-zone combustion system, or a first uniform combustion system. When the signal is a selection signal for the second uniform combustion method, an ON signal for controlling the close of the swirl valve 10 to close the main port 1b and the sub port 1d is output to the drive circuit 13e of the swirl valve 10 Only swirl valve 10
Is controlled to be opened to output an OFF signal for opening the main port 1b and the sub port 1d to the drive circuit 13e.

Next, the operation of the embodiment of the swirl 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 13f of the electronic control unit 13 inputs the intake air amount signal Q and the crank angle signal θ as described above (step 1), and the engine rotation is performed based on these input signals Q and θ. The number N and the engine load are calculated (step 2). Using the calculated engine speed N and engine load as parameters, the combustion mode map shown in FIG. 5 shows that the stratified charge combustion method is used in the low and medium load operation range of the engine 1 and the load level in the high load operation range except for the vicinity of the fully open throttle. The first uniform combustion method is used in a comparatively light region, the second uniform combustion method is used in a region near the throttle fully opening in the high load operating region, and the engine intermediate load operation between the low and medium load operating region and the high load operating region is performed. In the region, the two-zone combustion system is selected (step 3), and the selection signal M is output to the swirl valve opening / closing control means 13j.

In the subsequent step 4, the combustion system selecting means 1
It is determined whether the combustion method selected by 3f is a stratified combustion method, a two-zone combustion method, or a uniform combustion method (first uniform combustion method or second uniform combustion method). When the determination result is the stratified charge combustion method, the combustion method selection unit 13f outputs the intake air amount signal Q and the engine speed signal N to the stratified charge fuel injection control unit 13g, so that the stratified charge fuel injection is performed. The control means 13g searches the map for the basic fuel injection amount of the in-cylinder injector 11 and selects the pattern A shown in the fuel injection timing chart of FIG. 6 (step 5). The stratified charge fuel injection control means 13g sends the fuel injection control signal Ti ₁ to the in-cylinder injector 11 at the latter stage of the compression stroke immediately before ignition.
Is output to the drive circuit 13c, and then the flag F is set to 1 (step 6).

If the result of the determination in step 4 is the two-zone combustion system, the combustion system selection means 13f is set to two.
By outputting the intake air amount signal Q and the engine speed signal N to the zone combustion fuel injection control means 13h, the two-zone combustion fuel injection control means 13h is shared by the in-cylinder injector 11 and the port injection injector 12. A map is searched for each fuel injection amount and the pattern B shown in the fuel injection timing chart of FIG. 6 is selected (step 7). Then, the fuel injection control means 13h for two-zone combustion outputs the fuel injection control signal T immediately before the intake stroke.
i ₂ is output to the drive circuit 13d of the port injection injector 12 and the fuel injection control signal Ti ₁ is output to the drive circuit 13c of the in-cylinder injector 11 in the latter stage of the compression stroke, which is immediately before ignition. Is set to 2 (step 8).

Further, when the determination result of the step 4 is the uniform combustion system (the first uniform combustion system or the second uniform combustion system), the combustion system selection means 13f causes the uniform combustion fuel injection control means 13i to intake air. By outputting the quantity signal Q and the engine speed signal N, the uniform combustion fuel injection control means 13i performs a map search for the basic fuel injection quantity of the port injection injector 12 and also the pattern C shown in the fuel injection timing chart of FIG. Is selected (step 9). Then, the fuel injection control means 13i for uniform combustion outputs the fuel injection control signal Ti ₂ to the drive circuit 13d of the port injection injector 12 immediately before the intake stroke, and subsequently the flag F is set to 3 (step 10).

Next, is the flag F = 3 in order to determine whether the combustion method selected by the combustion method selecting means 13f is the uniform combustion method (first uniform combustion method or second uniform combustion method)? Whether or not it is determined (step 11), and if the determination result is YES, it is subsequently determined whether or not the combustion method is the second uniform combustion method (step 12).
If the determination result is YES, the swirl valve opening / closing control means 13j outputs an OFF signal to the drive circuit 13e to open the swirl valve 10 (step 1).
3).

On the other hand, the determination result of step 11 is NO.
If so, it is considered that the selected combustion method is the stratified combustion method or the two-zone combustion method, and if the determination result of step 12 is NO, it is considered that the selected combustion method is the first uniform combustion method. In this case, the swirl valve opening / closing control means 13j outputs an ON signal to the drive circuit 13e to control the swirl valve 10 to close (step 1).
4).

That is, in the present embodiment, the stratified charge combustion method is selected in the engine low and medium load operation region so that the in-cylinder injector 11 is directed from the center of the combustion chamber 1a toward the center of the cylinder bore in the latter stage of the compression stroke. High-pressure fuel is directly injected, and stratified charge combustion occurs when an ignition plug (not shown) ignites a rich mixture generated by the fuel spray.

At this time, the swirl valve opening / closing control means 13
j controls the swirl valve 10 to close and close the main port 1b.
Since the sub-port 1d is closed and the swirl port 1c is opened, a swirl flow is generated in the cylinder during the intake stroke. Therefore, the fuel spray injected from the central portion of the combustion chamber 1a toward the center of the cylinder bore by the in-cylinder injector 11 is less likely to be surrounded by the swirl flow and inadvertently diffused, and stable and favorable stratification can be achieved. Since combustion is performed, the fuel efficiency is greatly improved by making the air-fuel ratio significantly lean.

Further, by selecting the two-zone combustion system in the engine intermediate load operation region, fuel is injected from the port injection injector 12 into the main port 1b of the intake port immediately before the intake stroke, and this fuel is stored in the cylinder. In the latter half of the compression stroke, the in-cylinder injector 11 directly injects a small amount of fuel for ignition from the central portion of the combustion chamber 1a, and the fuel spray atomizes the rich air-fuel mixture for ignition. It is generated in the air-fuel mixture, and by igniting this rich air-fuel mixture, uniform combustion accompanied by stratified combustion, that is, two-zone combustion is performed.

At that time, the swirl valve opening / closing control means 13
j controls the swirl valve 10 to close and opens only the swirl port 1c of the intake port as in the above-described stratified charge combustion, and a swirl flow of a homogeneous mixture is generated in the cylinder during the intake stroke. Then, the swirl flow of the homogeneous mixture surrounds the rich mixture for ignition injected from the port injection injector 12, whereby uniform combustion with favorable stratified combustion is performed. Further, since the swirl flow of the homogeneous air-fuel mixture is converted into a turbulent component in the latter part of the compression stroke to generate a turbulent flow, turbulent combustion with a high combustion speed is accompanied and combustion is accelerated. In this way, the emission is further improved and the fuel economy is also improved.

In the engine high load operation region, the first uniform combustion system or the second uniform combustion system is selected, so that the fuel is injected from the port injector 12 into the main port 1b of the intake port immediately before the intake stroke. By uniformly igniting the uniform mixture generated in the cylinder by the fuel spray, uniform combustion is achieved.

In this case, the swirl valve opening / closing control means 13j is also used when the first uniform combustion system is selected in the engine high load operation region except the region where the throttle is fully opened.
Closes the swirl valve 10 to open only the swirl port 1c of the intake port as in the stratified charge combustion and the two-zone combustion described above, and a swirl flow of a uniform mixture is generated in the cylinder during the intake stroke. It Since the swirl flow of this homogeneous mixture is converted into a turbulent component in the latter part of the compression stroke to generate turbulent flow, the homogeneous mixture in the combustion chamber 1a performs good homogeneous combustion accompanied by turbulent combustion. Even in this high load region, combustion is promoted, emission is further improved, and fuel economy is further improved.

On the other hand, when the second uniform combustion system is selected in the engine high load operation range near the throttle fully open range, the swirl valve opening / closing control means 13j controls the swirl valve 10 to open to control the intake port. The main port 1b and the sub-port 1d are opened together with the swirl port 1c, so that the intake air flows into the main port 1b and the sub-port 1
High output can be obtained by ensuring a sufficient amount of intake air from all of the d and swirl ports 1c. Further, since the swirl flow is not generated in the cylinder, as a result, the situation that the swirl flow is converted into a turbulent component in the latter half of the compression stroke and the combustion speed is excessively increased to cause knocking is avoided. Therefore, good uniform combustion without knocking is performed.

That is, according to the present embodiment, stable and favorable stratified combustion and uniform combustion are compatible with each other, so that the emission is further improved and the fuel consumption and the output are further improved.

The present invention is not limited to the embodiment described above, but includes only the in-cylinder injector 11 for directly injecting high-pressure fuel into the combustion chamber 1a as the fuel injection valve means. It is also applied to a fuel injection engine in which the internal injection injector 11 injects fuel in the latter stage of the compression stroke to perform stratified combustion in the engine low-medium load operating region, and injects fuel from the beginning of the intake stroke to uniformly burn in the engine high-load operating region. it can.

[0042]

As described above, in the inventions described in claims 1 and 2, when the stratified charge combustion method is selected by the selection means in the engine low and medium load operation region, the stratified charge combustion is performed by the control of the fuel injection valve. At this time, the swirl valve opening / closing control means controls the swirl valve to close. For this reason, a swirl flow is generated in the cylinder during the intake stroke, and this swirl flow surrounds the fuel spray for stratified combustion injected from the fuel injection valve to prevent inadvertent diffusion. Stable and good stratified combustion is performed, emission is improved, and fuel consumption is improved.

Further, when the uniform combustion method is selected by the selecting means in the engine high load operation region, uniform combustion is performed by the control of the fuel injection valve, and at this time, the engine load operation region is compared with the load except the vicinity of the full throttle opening. If the region is relatively light, the swirl valve opening / closing control means closes the swirl valve 10. Therefore, a swirl flow of a homogeneous air-fuel mixture is generated in the cylinder during the intake stroke, and this swirl flow is converted into turbulent components in the latter part of the compression stroke, resulting in good uniform combustion accompanied by turbulent combustion with a high combustion speed. And combustion is promoted.

On the other hand, in the case of uniform combustion in the engine high load operating region, if the engine load operating region is in the region near the throttle fully opening, the swirl valve opening / closing control means controls the swirl valve 10 to open. For this reason, a sufficient amount of intake air is ensured and a swirl flow is not generated in the cylinder, and as a result, the combustion speed is excessively increased due to conversion of the swirl flow into a turbulent component, and knocking occurs. It is avoided and good homogeneous combustion is achieved.

According to the second aspect of the present invention, the swirl valve opening / closing control means closes the swirl valve 10 even when the two-zone combustion method is selected by the selection means at the time of intermediate load of the engine and the two-zone combustion is performed. . For this reason,
A swirl flow of a homogeneous air-fuel mixture is generated in the cylinder during the intake stroke, and this swirl flow surrounds the fuel spray for stratified combustion injected from the fuel injection valve to prevent inadvertent diffusion, Uniform combustion with good stratified combustion takes place. Further, the swirl flow of the generated homogeneous air-fuel mixture is converted into a turbulent component in the latter part of the compression stroke, and turbulent combustion with a high burning velocity is accompanied, whereby combustion is promoted.

Therefore, according to the first and second aspects of the present invention, both stable and favorable stratified combustion and uniform combustion can be achieved to improve the emission as a whole and to further improve the fuel consumption and the output. .

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of the invention according to claims 1 and 2.

FIG. 2 is an overall schematic configuration diagram of an embodiment.

FIG. 3 is a cross-sectional view showing a schematic structure of an intake port in one 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 Suction Pipe 3 Air Cleaner 4 Air Flow Meter 5 Throttle Valve 6 Exhaust Pipe 7 Catalytic Converter 8 Muffler 9 Partition 10 Swirl Valve 11 Cylinder Injection Injector (First Fuel Injection Valve Means) 12 Port Injection Injector (Second Fuel Injection) Valve means) 13 Electronic control device 13a A / D converter 13b Waveform shaping circuit 13c, 13d, 13e Drive circuit 13f Combustion method selection means 13g Stratified combustion fuel injection control means 13h Two-zone combustion fuel injection control means 13i Uniform combustion fuel Injection control means 13j Swirl valve opening / closing control means 13j 14 Crank angle sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02D 43/00 301 J U

Claims (3)

[Claims] 1. An engine intake passage is provided with a swirl valve that is controlled to open and close to generate a swirl flow in a cylinder when the intake passage is closed, and a fuel injection valve is controlled based on an engine operating state to reduce an engine low / medium load. In a fuel injection type engine that performs stratified combustion in the operating region and uniformly burns in the engine high load operating region, a selection means that selectively selects each of the combustion modes of the stratified combustion or the uniform combustion based on the engine speed and the engine load. When the stratified charge combustion method is selected or when the uniform combustion method is selected in the high load operating range except near the throttle full opening, the swirl valve is closed and the swirl is selected when the uniform combustion method is selected in the high load operating range near the throttle fully open. And a swirl valve opening / closing control means for controlling the opening of the valve. Lumpur controller. 2. An engine intake passage is provided with a swirl valve that is controlled to open and close to generate a swirl flow in the cylinder when the intake passage is closed, and the fuel injection valve is controlled based on the engine operating condition to reduce the engine load. In a fuel injection engine that performs stratified combustion in the operating region and uniformly burns in the engine high load operating region, first fuel injection valve means for directly injecting high-pressure fuel from the center of the combustion chamber toward the center of the cylinder bore, and intake Second fuel injection valve means for injecting low-pressure fuel into the system, and stratified combustion method is selected based on the engine speed and engine load at low and medium engine loads, and both stratified combustion and uniform combustion are performed at intermediate engine load. When the zone combustion method is selected and the uniform combustion method is selected when the engine is under heavy load, and when the stratified combustion method is selected The fuel is injected only from the first fuel injection valve means, and when the two-zone combustion system is selected, the fuel injection amount is shared so that the fuel is injected from the second fuel injection valve means and the first fuel injection is performed. Fuel injection control means for injecting fuel from the valve means and injecting fuel only from the second fuel injection valve means when the uniform combustion method is selected, when stratified combustion method is selected, when two-zone combustion method is selected, and The swirl valve is controlled to be closed when the uniform combustion method is selected in the high load operating range except near the throttle fully opening, and the swirl valve is controlled to be opened when the uniform combustion method is selected in the high load operating range near the throttle fully opening. A swirl control device for a fuel injection engine, comprising: a control means. 3. The fuel injection control means sets the fuel injection timing from the first fuel injection valve means to the latter half of the compression stroke, and sets the fuel injection timing from the second fuel injection valve means immediately before the intake stroke. The swirl control device for a fuel injection type engine according to claim 2, wherein: