JPH07293304A - Tumble control device for fuel injection type engine - Google Patents

Abstract

PURPOSE:To improve emission synthetically and more improve fuel consumption and output by selecting each one of combustion styles of stratified combustion and uniform combustion alternatively, and controlling opening/closing of a tumble valve properly. CONSTITUTION:A tumble valve 10 for forming tumble flow is provided in the air intake passage 2 of an engine 1. Especially, a selecting means is provided therein so as to select each one of combustion styles of stratified combustion and uniform combustion alternatively on the basis of engine rotational speed and an engine load. The opening/closing control means of the tumble valve 10 is also provided, so that the tumble valve 10 is opening controlled when the stratified combustion style is selected and when the uniform combustion style is selected in the high load operating range near the full opening of a throttle. The tumble valve 10 is closing controlled when the uniform combustion style is selected in a high load operating range except near full opening of the throttle. It is thus possible to improve emission synthetically without deteriorating the advantage of original stratified combustion style and the uniform combustion style, and more improve fuel consumption and output.

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 the 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 engine operating state. The present invention relates to a tumble 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, 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-cylinder injection injectors that directly inject high-pressure fuel into the combustion chamber and port-injection injectors that inject low-pressure fuel into the intake port are used together. High-pressure fuel is directly injected from the injection injector into the combustion chamber for stratified combustion, and in the high-load operating region of the engine, low-pressure fuel is injected from the port injection injector into the intake port immediately before the intake stroke so that uniform combustion is achieved. There is a fuel injection engine.

[0004]

By the way, even in the fuel injection type engine in which the combustion system is switched to the stratified combustion system and the uniform combustion system in this way, there is no room for improvement, and the emission is further improved and the fuel consumption is improved. And, it is desired to further improve the output.

As means for responding to this demand, for example, the technology described in JP-A-2-230920, JP-A-3-89936 and JP-A-3-185213 is used to generate a tumble flow in the cylinder during the suction stroke. It is considered effective to promote combustion by utilizing the fact that the generated tumble flow collapses and becomes turbulent in the latter half of the compression stroke.

However, the stratified combustion system and the uniform combustion system are completely different in the state of mixture formation, and if a tumble flow is generated when the high-pressure fuel is directly injected from the in-cylinder injector into the combustion chamber for stratified combustion, The injected fuel spray diffuses due to the tumble flow, which hinders the production of a rich air-fuel mixture. This means that good stratified charge combustion cannot be performed, which may rather lead to deterioration of fuel consumption and emission in the low and medium load operating range of the engine. In addition, if a tumble flow is generated during uniform combustion in a high load and high rotation range, the combustion speed may be excessively increased due to the turbulence, and knocking may occur.

Therefore, the present invention provides a tumble control device for a fuel injection type engine which can improve emissions comprehensively and further improve fuel consumption and output without impairing the advantages of the original stratified combustion system and uniform combustion system. The purpose is to provide.

[0008]

In order to achieve this object, a tumble control device for a fuel injection 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 tumble valve 10 that is controlled to open and close to generate a tumble 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 the 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 operation area near the throttle full opening, the tumble valve 10 is controlled to be opened. When the uniform combustion method is selected in the high load operation area except near the throttle fully opening, the tumble valve 10 is selected. A tumble valve opening / closing control means for controlling the closing is provided.

Here, the fuel injection engine is provided with the above-mentioned in-cylinder injection injector and port injection injector as fuel injection valves, and is stratified by fuel injection from the in-cylinder injection injector in a low-to-medium load operating region of the engine. Some of them are combusted and uniformly burned by fuel injection from the port injection injector in the high load operation region of the engine. Further, it is provided with only the in-cylinder injection injector as a fuel injection valve, and in the low-medium load operating region of the engine, fuel is injected and stratified combustion in the latter stage of the compression stroke, and in the high-load operating region of the engine, fuel injection is performed at the beginning of the intake stroke. Also included are those that burn uniformly.

A tumble control device for a fuel injection type engine according to a second aspect of the present invention is a tumble valve 10 for generating a tumble flow in a cylinder when the intake passage 2 of the engine 1 is controlled to be opened and closed. In addition, the fuel injection valve is controlled based on the engine operating state to perform stratified combustion in the engine low-medium load operating region and perform uniform combustion in the engine high-load operating region. The first fuel injection valve means 11 for injecting the fuel, the second fuel injection valve means 12 for injecting low-pressure fuel to the intake system, and the stratified charge combustion method is selected based on the engine speed and the engine load when the engine is at low and medium loads. Selects a two-zone combustion method that uses both stratified combustion and uniform combustion when the engine has an intermediate load, and uniform combustion when the engine has a high load. And the second fuel injection by sharing the fuel injection amount when selecting the two-zone combustion method, and injecting fuel only from the first fuel injection valve means 11 when selecting the stratified charge combustion method. The fuel is injected from the valve means 12 and the first fuel injection valve means 1 is also provided.
Fuel injection control means for injecting fuel from No. 1 and for injecting fuel only from the second fuel injection valve means 12 when the uniform combustion method is selected, and in the high load operation region near the full throttle opening when the stratified charge combustion method is selected. When the uniform combustion method is selected, the tumble valve 10 is controlled to be opened. When the two-zone combustion method is selected and when the uniform combustion method is selected in the high load operation region except near the throttle fully opening, the tumble valve 10 is controlled.
And tumble valve opening / closing control means for controlling the closing of the valve.

Here, 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) sets the fuel injection timing from the first fuel injection valve means 11 to the latter stage of the compression stroke, and sets the fuel injection timing from the second fuel injection valve means 12 immediately before the intake stroke. It is characterized by doing.

[0012]

In the tumble control device for a fuel injection type engine according to claims 1 and 2, when the stratified charge combustion system is selected by the selecting means in the engine low and medium load operating region, the tumble valve opening / closing control means operates the tumble valve 10. Open control. Therefore, the tumble flow is not generated in the cylinder, and as a result, the fuel spray injected from the first fuel injection valve 11 into the cylinder is diffused by the tumble flow and the generation of the rich mixture is hindered. This situation is avoided in advance, and good stratified combustion is performed.

Further, even when the uniform combustion method is selected by the selecting means in the engine high load operating region and the engine operating region is the high load operating region near the throttle fully opening, the tumble valve opening / closing control means is also operated. The tumble valve 10 is controlled to open. Therefore, a sufficient amount of intake air is secured, and no tumble flow is generated in the cylinder,
As a result, the situation in which knocking occurs due to the combustion speed rising too much due to the tumble flow is avoided in advance.
Good uniform combustion is achieved.

On the other hand, when the uniform combustion method is selected by the selecting means in the engine high load operating region, and the engine operating region is the high load operating region except near the throttle fully opening state, and claim 2 When the two-zone combustion method is selected for the fuel injection engine, the tumble valve opening / closing control means controls the tumble valve 10 to close.
Therefore, a tumble flow is generated in the cylinder of the suction stroke, and this tumble flow collapses and becomes turbulent in the latter part of the compression stroke, so that the combustion state becomes turbulent combustion and combustion is promoted. Yes, emission and fuel consumption can be improved.

[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 engine and a tumble control device thereof according to one embodiment. An intake pipe 2 that constitutes 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. 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, in the intake port of the engine 1, a main passage 1b communicating with the peripheral portion of the combustion chamber 1a by a partition wall 9 and a sub passage 1c communicating with the vicinity of the central portion of the combustion chamber 1a.
It is divided into and. A tumble valve 10 that opens and closes the main passage 1b is installed in the intake port.

The engine 1 includes an in-cylinder injector 11 for directly injecting high pressure fuel into a combustion chamber 1a in which a spark plug (not shown) is installed, and a port injection for injecting low pressure fuel into a sub passage 1c of an intake port. Injector 1
And 2 as first and second fuel injection valve means, respectively controlling the fuel injection amount and fuel injection timing of the in-cylinder injector 11 and the port injector 12, and controlling the opening and closing of the tumble valve 10. The electronic control unit 13 is provided. And this engine 1
Includes a crank angle sensor 14 for detecting the rotation angle of the crankshaft and outputting the detection signal to the electronic control unit 13.
Is attached.

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. Opening and closing control signals ON and O are sent to the tumble valve 10 via the circuit 13e.
FF is output.

FIG. 3 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 tumble 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, the four combustion methods from the combustion method map shown in FIG. 4, that is, the stratified charge combustion method in the low and medium load operation region of the engine 1,
The first uniform combustion method is used in the high load operation area near the throttle full opening, and the second uniform combustion method is used in the high load operation area except near the throttle full opening. The engine intermediate load between the low and medium load operation area and the high load operation area. In the operating region, the two-zone combustion method is selected, and the selection signal M is output to the tumble 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.
When the two-zone combustion system is selected for g, the two-zone combustion fuel injection control means 13h is set to the second uniform combustion system or the first
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 is searched as a parameter, and based on the pattern A shown in the fuel injection timing chart of FIG. 5, the fuel injection control signal Ti ₁ is output immediately after ignition in the latter stage of the compression stroke. 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
And the parameters are used as a parameter to search the map for the basic fuel injection amount of the port injection injector 12, and based on the pattern C shown in the fuel injection timing chart of FIG. 5, the fuel injection control signal Ti _{2 is set} to the port injection injector 12 immediately before the intake stroke. 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. 5, 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 tumble valve opening / closing control means 13j responds to the combustion system selection signal M input from the combustion system selection means 13f, which is a stratified combustion system selection signal or a first uniform combustion system selection signal. Often, the OF is opened to control the tumble valve 10 to open the main passage 1b.
The F signal is output to the drive circuit 13e of the tumble valve 10, and when it is the selection signal of the two-zone combustion method or the second uniform combustion method, the tumble valve 10 is controlled to be closed and the ON signal for closing the main passage 1b is driven. Circuit 13
output to e.

Next, the operation of an embodiment of the tumble control device for the fuel injection type engine constructed as described above will be described with reference to the flowcharts of FIGS. 6 and 7. 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). Then, using the calculated engine speed N and engine load as parameters, a stratified combustion method is used in the low and medium load operation range of the engine 1 and a first uniform combustion method is used in the high load operation range near the full throttle opening according to the combustion mode map shown in FIG. The second uniform combustion system is selected in the high load operating region except near the throttle fully opening, and the two zone combustion system is selected in the engine intermediate load operating region between the low load operating region and the high load operating region (step 3). The selection signal M is output to the tumble 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. 5 (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. 5 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).

Subsequently, it is determined whether or not the flag F = 1 in order to determine whether the combustion method selected by the combustion method selecting means 13f is the stratified combustion method (step 1).
1) If the determination result is YES, the tumble valve opening / closing control means 13j outputs an OFF signal to the drive circuit 13e to control the opening of the tumble valve 10 (step 12).

Here, the determination result of step 11 is NO.
Is the flag F = 3 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). Is subsequently determined (step 13). If the result of this determination is YES, it is then determined whether or not it is the first uniform combustion system (step 14). If the result of this determination is YES, then the process proceeds to step 12 and the opening control of the tumble valve 10 is performed. Is executed.

On the other hand, the determination result of step 13 is NO.
If so, it is considered that the selected combustion method is the two-zone combustion method, and if the result of the determination at step 14 is NO, it is considered that the selected combustion method is the second uniform combustion method. Tumble valve opening / closing control means 1
3j outputs an ON signal to the drive circuit 13e to control the closing of the tumble valve 10 (step 15).

That is, in this embodiment, the stratified charge combustion method is selected in the engine low / medium load operation range, so that the in-cylinder injector 11 to the combustion chamber 1a is selected in the latter stage of the compression stroke.
High-pressure fuel is directly injected into the inside. Then, stratified combustion is performed by igniting the rich mixture generated by the fuel spray.

At this time, the tumble valve opening / closing control means 13
Since j controls the opening of the tumble valve 10 to open the main passage 1b of the intake port, the generation of the tumble flow in the cylinder in the intake stroke is stopped. Therefore, the situation in which the fuel spray injected from the in-cylinder injector 11 is diffused by the tumble flow and the generation of the rich mixture is obstructed can be avoided in advance. Good stratified combustion with a significantly lean air-fuel ratio is performed, and fuel efficiency is greatly improved.

Further, in the engine intermediate load operating region, the two-zone combustion system is selected, so that the low-pressure fuel is injected from the port injection injector 12 into the sub passage 1c of the intake pipe 2 immediately before the intake stroke, and then this fuel is injected. In the latter half of the compression stroke, when a uniform mixture is formed in the cylinder, a small amount of high pressure fuel for ignition is directly injected from the in-cylinder injector 11 into the combustion chamber 1a. Then, the fuel spray produces a rich mixture for ignition in the homogeneous mixture, and by igniting the rich mixture, uniform combustion accompanied by stratified combustion, that is, two-zone combustion is performed.

At that time, the tumble valve opening / closing control means 13
j controls the tumble valve 10 to close and closes the main passage 1b of the intake port, and the intake is performed only through the sub passage 1c communicating with the vicinity of the central portion of the combustion chamber 1a. Produces a tumble flow. Therefore, in the latter half of the compression stroke, a turbulent flow is generated due to the collapse of the tumble flow, and the turbulent flow causes turbulent combustion of the homogeneous air-fuel mixture in the combustion chamber 1a, thus promoting combustion in the engine intermediate load operating region. The emission is further improved and the fuel economy is also improved.

In the engine high load operation range, the first uniform combustion system or the second uniform combustion system is selected, so that the low-pressure fuel is injected from the port injection injector 12 into the sub passage 1c of the intake port immediately before the intake stroke. It Then, the fuel spray ignites a uniform mixture generated in the cylinder, thereby causing uniform combustion.

At this time, when the second uniform combustion system is selected in the engine high load operating region except near the throttle fully opening, the tumble valve opening / closing control means 13j controls the tumble valve 10 to close the intake port. Main passage 1
Since b is closed and the intake air is performed only through the sub passage 1c communicating with the vicinity of the center of the combustion chamber 1a, a tumble flow is generated in the cylinder during the intake stroke. Therefore, in the latter half of the compression stroke, a turbulent flow is generated due to the collapse of the tumble flow, and the turbulent flow causes the turbulent combustion of the homogeneous mixture in the combustion chamber 1a. In, the combustion is promoted, the emission is further improved, and the fuel consumption is further improved.

On the other hand, when the first uniform combustion system is selected in the engine high load operation region near the throttle fully opening, the tumble valve opening / closing control means 13j controls the opening of the tumble valve 10 to open the main passage of the intake port. 1b is opened, intake is performed from both the main passage 1b and the sub passage 1c to secure a sufficient intake amount, and tumble flow is not generated in the cylinder. Therefore,
Turbulent flow due to the collapse of the tumble flow can prevent the situation that the combustion speed is too high and knocking occurs.Thus, in the engine high load operation area near the full throttle opening, the intake air quantity is sufficiently secured and high. Good uniform combustion is performed to obtain an output.

That is, according to the present embodiment, the emission is further improved and the fuel consumption and the output are further improved without impairing the advantages of the original stratified charge combustion method and uniform combustion method.

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.

[0043]

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 range, the tumble valve opening / closing control means controls the opening of the tumble valve. To do. Therefore, the tumble flow is not generated in the cylinder, and as a result, the fuel spray injected from the fuel injection valve into the cylinder is diffused by the tumble flow and the generation of the rich mixture is obstructed. Therefore, good stratified charge combustion is performed.

Further, even when the uniform combustion method is selected by the selecting means in the engine high load operating region and the engine operating region is the high load operating region near the throttle fully opening, the tumble valve opening / closing control means also operates. Open the tumble valve. For this reason, a sufficient amount of intake air is ensured and a tumble flow is not generated in the cylinder, and as a result, a situation in which the combustion speed is excessively increased by the tumble flow and knocking occurs can be avoided. Uniform combustion is performed.

On the other hand, when the uniform combustion method is selected by the selecting means in the engine high load operating region, and the engine operating region is the high load operating region except near the throttle fully opening, and claim 2 When the two-zone combustion method is selected for the fuel injection engine, the tumble valve opening / closing control means controls the tumble valve to close. Therefore, a tumble flow is generated in the cylinder during the intake stroke, and this tumble flow collapses and becomes turbulent in the latter part of the compression stroke, so that the combustion state becomes turbulent combustion and combustion is accelerated. Yes, emission and fuel consumption can be improved.

Therefore, according to the first and second aspects of the present invention, it is possible to further improve the emission as a whole and further improve the fuel consumption and the output without impairing the original advantages of the stratified charge combustion method and the uniform combustion method. it can.

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

FIG. 4 is a combustion method map used in one embodiment.

FIG. 5 is a fuel injection timing timing chart used in one embodiment.

FIG. 6 is a flowchart showing the operation of one embodiment.

FIG. 7 is a flowchart showing the operation of the 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 Tumble 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 Tumble valve opening / closing control means 14 Crank angle sensor

Claims (3)

[Claims] 1. An engine intake passage is provided with a tumble valve that is controlled to open and close to generate a tumble flow in the cylinder when the intake passage is closed, and the fuel injection valve is controlled based on the engine operating state to reduce the engine 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 operation area near the throttle full opening, the tumble valve is controlled to open, and the tumble is selected when the uniform combustion method is selected in the high load operation area except near the throttle fully opening. And a tumble valve opening / closing control means for controlling the closing of the valve. Bull controller. 2. An engine intake passage is provided with a tumble valve that is controlled to open and close to generate a tumble 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 type 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 into the combustion chamber and second for injecting low pressure fuel into the intake system. Of the fuel injection valve means, the stratified charge combustion method is selected at low and medium load of the engine based on the engine speed and the engine load, and the two-zone combustion method by both stratified combustion and uniform combustion is selected at the intermediate load of the engine. When the load is high, the uniform combustion method is selected, and when the stratified combustion method is selected, only the first fuel injection valve means is used. Of the uniform combustion system, the fuel injection amount is shared and the fuel is injected from the second fuel injection valve unit while the fuel is injected from the first fuel injection valve unit when the two-zone combustion system is selected. At the time of selection, the fuel injection control means for injecting fuel only from the second fuel injection valve means, and at the time of selection of the stratified charge combustion method and at the time of selection of the uniform combustion method in the high load operation region near the throttle full opening, the tumble valve is opened. And a tumble valve opening / closing control means for controlling the tumble valve to be closed when the two-zone combustion method is selected and when the uniform combustion method is selected in a high load operation range except near the throttle full opening. Engine tumble control device. 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 tumble control device for a fuel injection type engine according to claim 2, wherein