JPH07293301A - Fuel injection type engine controller for vehicle - Google Patents

Abstract

PURPOSE:To enable an engine to be operated continuously even, when any abnormal condition is generated in the fuel injection system of an inter-cylinder injector, resulting in impossibility of injecting high pressure fuel, and also enable any abnormal generation of high pressure fuel to be informed to a driver. CONSTITUTION:A fuel injection type controller is provided with a first fuel injection valve means 11 for directly injecting high pressure fuel to a combustion chamber, a second fuel injection valve means 12 for injecting low pressure fuel to an intake system, an abnormal condition displaying means for displaying abnormal condition on a display device 15 when an abnormal condition is judged on the basis of the detected signal of an abnormal condition detecting means 14 for detecting abnormal condition in the fuel injection system of the first fuel injection valve means 11, a means for uniformly selecting a uniform combustion style at the time of input of the abnormal condition judging signal as well as selecting a stratified combustion style in a low and intermediate load operating range and selecting a uniform combustion system in a high load operating range, and a fuel injection control means for injecting fuel from only the first fuel injection valve means 11 when the stratified combustion style is selected and for injecting fuel from only the second fuel injection valve means 12 when the uniform combustion style is selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine load by fuel injection control of first fuel injection valve means for directly injecting high pressure fuel into a combustion chamber and second fuel injection valve means for injecting low pressure fuel into an intake system. The present invention relates to a control device for a vehicle fuel injection type engine that performs stratified combustion or uniform combustion according to an operating region, and more specifically, relates to a fail safe when an abnormality occurs in the fuel injection system of the first fuel injection valve means. .

[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 makes it possible to make the overall air-fuel ratio lean, so that the fuel consumption can be improved in the low and medium load operating range of the engine. It is generally known in the past that the uniform combustion method of igniting a homogeneous mixture can improve the output in a high load operation region of the engine.

Therefore, various fuel injection engines for vehicles have been conventionally proposed in which the combustion system is switched between the stratified combustion system and the uniform combustion system according to the load operation region of the engine. For example, the in-cylinder injection injector as the first fuel injection valve means for directly injecting the high-pressure fuel into the combustion chamber and the port injection injector as the second fuel injection valve means for injecting the low-pressure fuel into the intake port are used together. Then
In the low and medium load operating range of the engine, high-pressure fuel is directly injected from the in-cylinder injector into the combustion chamber for stratified combustion in the latter part of the compression stroke, and in the high load operating range of the engine, port injection is performed immediately before the intake stroke. There is a fuel injection engine for a vehicle in which low-pressure fuel is injected from an injector into an intake port for uniform combustion.

[0004]

By the way, the in-cylinder injector has a relationship of injecting fuel in the latter stage of the compression stroke in which the in-cylinder pressure, which is the pressure in the cylinder, increases, and the fuel injection pressure is 40 to 100 kgf / cm @ 2. A high pressure of a certain degree is required. Therefore, if some abnormality occurs in the fuel injection system of the in-cylinder injector and it becomes impossible to inject high-pressure fuel, the engine may not be able to operate in the low to medium load operation region at all, and the fail safe Measures are required.

Incidentally, in a fuel injection engine for a vehicle, there is a technique described in Japanese Patent Laid-Open No. 60-90942 as a countermeasure when an abnormality occurs in the fuel supply to each cylinder. The fuel supply to the in-cylinder injector for directly injecting high-pressure fuel into the combustion chamber is to prevent the fuel from being continuously over-supplied or under-supplied by stopping the fuel supply to the cylinder where the abnormality occurs. It is not possible to cope with abnormalities in the injection system.

Therefore, according to the present invention, the engine is operated even when the high-pressure fuel cannot be injected due to some abnormality in the fuel injection system of the in-cylinder injector as the first fuel injection valve means. It is an object of the present invention to provide a control device for a fuel injection engine for a vehicle, which is capable of continuing the above-mentioned operation and notifying a driver of the occurrence of the abnormality.

[0007]

In order to achieve this object, a controller for a fuel injection engine for a vehicle according to a first aspect of the present invention controls a fuel injection valve on the basis of an engine operating state to reduce an engine low / medium load. In a fuel injection engine for a vehicle, which performs stratified combustion in an operating region and uniformly burns in an engine high load operating region, first fuel injection valve means 11 for directly injecting high-pressure fuel into a combustion chamber and low-pressure fuel into an intake system. The second fuel injection valve means 12, the abnormality detection means 14 for detecting an abnormality in the fuel injection system of the first fuel injection valve means 11, and the presence / absence of abnormality is determined based on the detection signal of the abnormality detection means 14. The abnormality determination means, the abnormality display means for displaying an abnormality on the display device 15 by inputting the abnormality determination signal from the abnormality determination means, and the engine low level based on the engine speed and the engine load. In the load operation region, the stratified charge combustion system is selected, in the engine high load operation region, the uniform combustion system is selected, and when the abnormality determination signal is input, a uniform combustion system is uniformly selected regardless of the engine load operation region. A fuel injection control means for injecting fuel only from the first fuel injection valve means 11 when the stratified charge combustion method is selected and for injecting fuel only from the second fuel injection valve means 12 when the uniform combustion method is selected. It is characterized by being provided.

According to a second aspect of the present invention, there is provided a control device for a fuel injection engine for a vehicle, which controls a fuel injection valve based on an engine operating state to perform stratified charge combustion in an engine low / medium load operating range and to perform engine high load operation. In a fuel injection engine for a vehicle that burns uniformly in a region, a first fuel injection valve means 11 that directly injects high-pressure fuel into a combustion chamber, a second fuel injection valve means 12 that injects low-pressure fuel into an intake system, Abnormality detection means 14 for detecting an abnormality in the fuel injection system of the first fuel injection valve means 11, abnormality determination means for determining whether or not there is an abnormality based on a detection signal from the abnormality detection means, and abnormality determination from the abnormality determination means. An abnormality display means for displaying an abnormality on the display device 15 by inputting a signal, and a stratified combustion method is selected in the engine low and medium load operation region based on the engine speed and the engine load. The two-zone combustion method by both stratified combustion and uniform combustion is selected in the engine intermediate load operation area, the uniform combustion method is selected in the engine high load operation area, and the engine load operation area is concerned when the abnormality determination signal is input. Without selecting the uniform combustion method uniformly, and when selecting the stratified combustion method, the fuel is injected only from the first fuel injection valve means 11 in the latter stage of the compression stroke.
When the zone combustion system is selected, the fuel injection amount is shared so that the fuel is injected from the second fuel injection valve means 12 immediately before the intake stroke, and the fuel is injected from the first fuel injection valve means 11 at the latter stage of the compression stroke. Fuel injection control means for injecting fuel and injecting fuel just before the intake stroke only from the second fuel injection valve means 12 when the uniform combustion method is selected.

In the third aspect of the invention, the abnormality detecting means in the first and second aspects of the invention can detect a change in the in-cylinder pressure according to the fuel injection state of the first fuel injection valve means. It is characterized by being an in-cylinder pressure sensor.

[0010]

According to the invention described in claims 1 and 2, when an abnormality occurs in the fuel injection system of the first fuel injection valve means, the abnormality determination means selects the combustion determination method based on the detection signal of the abnormality detection means. And the abnormality display means. Then, the combustion method selection means uniformly selects the uniform combustion method regardless of the engine load operating range, and the fuel injection control means is the second.
The fuel is injected only from the fuel injection valve means to cause uniform combustion, and at this time, the abnormality display means causes the display device to display an abnormality indicating that an abnormality has occurred in the fuel injection system of the first fuel injection valve means.

[0011]

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 a schematic overall structure of a fuel injection engine for a vehicle and a control system therefor 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 from an upstream side thereof. A valve 5 is sequentially installed, and a catalytic converter 7 and a muffler 8 are sequentially installed in an exhaust pipe 6 which constitutes an exhaust system.

The engine 1 is provided in a combustion chamber in which an ignition plug (not shown) is installed as first and second fuel injection valve means whose fuel injection amount and fuel injection timing are controlled by the electronic control unit 10. The in-cylinder injector 11 that directly injects high-pressure fuel and the port injector 12 that injects low-pressure fuel into the intake port are provided. In addition to the air flow meter 4 and the crank angle sensor 13 that detects the rotation angle of the crankshaft, the engine 1 includes, as sensors that output necessary detection signals to the electronic control unit 10, a cylinder that is the internal pressure of the cylinder. An in-cylinder pressure sensor 14 for detecting the internal pressure is provided as an abnormality detecting means.

The engine 1 has an electronic control unit 10
As a device whose operation is controlled by a control signal from
In addition to the in-cylinder injector 11 and the port injector 12, the display device 15 is provided to display an abnormality indicating that an abnormality has occurred in the fuel injection system of the in-cylinder injector 11.

The electronic control unit 10 includes a CPU, RO
An M / RAM, an input port, an output port, and a timer are microcomputers interconnected via a bus line. The A / D converters 10a and 10b and the waveform shaping circuit 10c connected to the input port are connected to the output port. Drive circuits 10d, 10e, 10f and the like to be connected are incorporated.

The intake air amount signal Q from the air flow meter 4 is input to the A / D converter 10a, the in-cylinder pressure signal P from the in-cylinder pressure sensor 14 is input to the A / D converter 10b, and the waveform shaping circuit is input. The crank angle signal θ from the crank angle sensor 13 is input to 10c. Further, a predetermined fuel injection control signal Ti is sent to the in-cylinder injector 11 via the drive circuit 10d.
₁ is output, and a predetermined fuel injection control signal Ti2 is output to the port injection injector 12 via the drive circuit 10e, and an abnormality display signal is output to the display device 15 via the drive circuit 10f. Has become.

FIG. 3 is a block diagram showing a part of the function of the electronic control unit 10. The combustion system selecting means 10g as selecting means and the stratified combustion fuel injection controlling means 10h as the fuel injection controlling means are shown. Two-zone combustion fuel injection control means 10i, uniform combustion fuel injection control means 10j,
The abnormality determination means 10k and the abnormality display means 10l are configured.

The combustion system selecting means 10g receives the intake air amount signal Q from the air flow meter 4 via the A / D converter 10a and the crank angle signal θ from the crank angle sensor 13 via the waveform shaping circuit 10c. Calculate the engine speed N and engine load based on
Using the engine speed N and the engine load as parameters, basically, according to the combustion method map shown in FIG. 4, the stratified charge combustion method is used in the engine low / medium load operation area, the uniform combustion method is used in the engine high load operation area, The two-zone combustion method is selected in the engine intermediate load operating region between the load operating region and the high load operating region.

Here, the combustion system selecting means 10g is
When an abnormality determination signal is input from the abnormality determination means 10k, the uniform combustion method is uniformly selected regardless of the engine load operating range. The combustion method selection means 10g is a fuel injection control means corresponding to the selected combustion method, that is, fuel injection control means 10h, 2 for stratified charge combustion.
The intake air amount signal Q and the engine speed signal N input to either the zone combustion fuel injection control means 10i or the uniform combustion fuel injection control means 10j are output.

The stratified charge fuel injection control means 10h searches the map for the basic fuel injection amount of the in-cylinder injector 11 by using the input intake air amount signal Q and the input engine speed signal N as parameters, and the fuel shown in FIG. Based on the pattern A shown in the injection timing chart, the fuel injection control signal Ti ₁ is output to the drive circuit 10d of the in-cylinder injector 11 at the latter stage of the compression stroke immediately before ignition.

Further, fuel injection control means 10j for uniform combustion
Is the input intake air amount signal Q and engine speed signal N
And the basic fuel injection amount of the port injection injector 12 as a parameter, 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 10e.

Further, the two-zone combustion fuel injection control means 10i 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 10d of the in-cylinder injector 11 at the latter stage of the compression stroke immediately before ignition.

On the other hand, the abnormality determining means 10k is
Based on the in-cylinder pressure signal P from the in-cylinder pressure sensor 14 input via the converter 10b, when the peak increase value of the in-cylinder pressure is less than or equal to a predetermined value, clogging of the in-cylinder injector 11 or failure of the fuel pump, It is considered that the fuel injection system of the in-cylinder injector 11 is abnormal, and an abnormality determination signal is output to the abnormality display means 10l and the combustion method selection means 10g.

Further, the abnormality display means 10l receives the abnormality determination signal from the abnormality determination means 10k, and the drive circuit 10
An abnormality display signal is output to f so that the display device 15 arranged on the instrument panel (not shown) of the vehicle displays an abnormality indicating that the fuel injection system of the in-cylinder injector 11 is abnormal. Has been done.

Next, the operation of an embodiment of the control device for the vehicle fuel injection type engine constructed as described above will be described with reference to the flow charts of FIGS. 6 and 7. During operation of the engine 1, the combustion system selection means 10g of the electronic control unit 10 inputs the intake air amount signal Q and the crank angle signal θ as described above (step 1), and the engine is based on these input signals Q and θ. The engine speed N and the engine load are calculated (step 2). 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 method is the stratified combustion method, the two-zone combustion method or the uniform combustion method. When the determination result is the stratified charge combustion method, the pattern A shown in the fuel injection timing chart of FIG. 5 is selected (step 5) and the flag F is set to 1 (step 6). Then, the stratified charge fuel injection control means 10h outputs the fuel injection control signal Ti ₁ to the drive circuit 10d of the in-cylinder injector 11 at the latter stage of the compression stroke immediately before ignition, so that the stratified charge combustion is performed in the engine low and medium load operating region. To do.

If the judgment result of the step 4 is the two-zone combustion system, the pattern B shown in the fuel injection timing chart of FIG. 5 is selected (step 7) and the flag F is set to 2 (step). 8). The two-zone combustion fuel injection control means 10i sends the fuel injection control signal Ti ₂ to the port injection injector 12 immediately before the intake stroke.
To the drive circuit 10d of the in-cylinder injector 11 to output the fuel injection control signal Ti ₁ to the drive circuit 10d of the in-cylinder injector 11 in the latter stage of the compression stroke, which is immediately before the ignition. In the engine intermediate load operating region between the two regions, two-zone combustion is performed by both stratified combustion and uniform combustion.

If the determination result of step 4 is the uniform combustion system, pattern C shown in the fuel injection timing chart of FIG. 5 is selected (step 9),
The flag F is set to 3 (step 10). Then, the uniform combustion fuel injection control means 10j outputs the fuel injection control signal Ti ₂ to the port injection injector 12 immediately before the intake stroke.
Output to the drive circuit 10e of No. 1, which causes uniform combustion in the engine high load operation region.

Subsequently, it is determined whether or not the flag F = 3 to determine whether or not the selected combustion system is the uniform combustion system (step 11). If the determination result is NO, the cylinder The abnormality determination means 10k inputs the cylinder pressure signal P from the cylinder pressure sensor 14 on the assumption that it is during the stratified combustion or the two-zone combustion for which the internal injection injector 11 should inject fuel (step 12).

In the following step 13, the abnormality determining means 10
Based on the in-cylinder pressure signal P input by k, it is determined whether or not there is an abnormality in the fuel injection system of the in-cylinder injector 11. That is, if the in-cylinder pressure increase peak value based on the in-cylinder pressure signal P is greater than or equal to a predetermined value, the fuel injection system of the in-cylinder injector 11 is normal, and if the in-cylinder pressure increase peak value is less than or equal to the predetermined value, the cylinder It is determined that there is an abnormality in the fuel injection system of the in-cylinder injector 11 such as clogging of the internal injector 11 or failure of the fuel pump.

When the result of the determination in step 13 is YES and there is an abnormality in the fuel injection system of the in-cylinder injector 11, the abnormality determination means 10k outputs an abnormality determination signal to the abnormality display means 10l and the combustion method selection means 10g. (Step 14). Therefore, the abnormality display means 10l outputs an abnormality display signal to the drive circuit 10f to cause the display device 15 to display an abnormality indicating that the fuel injection system of the in-cylinder injector 11 is abnormal (step 15), and then to step 1 Return. In addition, when the determination result of the said step 11 is YES and when the determination result of the said step 13 is NO, it returns to step 1 as it is.

Here, the combustion system selecting means 10g which has input the abnormality determination signal in the step 14 is operated in the step 3
The uniform combustion system is uniformly selected regardless of the engine load range, and the intake air amount signal Q and the engine speed signal N are output to the uniform combustion fuel injection control means 10j. Therefore, as described above, the uniform combustion fuel injection control means 1
0j outputs the fuel injection control signal Ti ₂ to the drive circuit 10e of the port injection injector 12 immediately before the intake stroke, thereby causing uniform combustion.

That is, according to the present embodiment, when the high-pressure fuel cannot be injected due to some abnormality in the fuel injection system of the in-cylinder injector 11, the fuel of the port injector 12 is injected. Since the uniform combustion is performed by the injection control, the engine 1 continues to operate in this manner, and at this time, the display device 15 displays an abnormality, thereby indicating that an abnormality has occurred in the fuel injection system of the in-cylinder injector 11. Notify the driver.

The block configuration in the electronic control unit 10 described above is merely an example, and the present invention is not limited to this. For example, a fuel injection control unit dedicated to an abnormality may be separately provided, which is activated by the input of the abnormality determination signal from the abnormality determination unit 10k and outputs a predetermined fuel injection control signal Ti ₂ to the drive circuit 10e of the port injection injector 12. Good.

[0034]

As described above, according to the first and second aspects of the present invention, when an abnormality occurs in the fuel injection system of the first fuel injection valve means, the abnormality determination means becomes abnormal based on the detection signal of the abnormality detection means. The determination signal is output to the combustion system selection means and the abnormality display means. Then, the combustion method selection means uniformly selects the uniform combustion method regardless of the engine load operating region, and the fuel injection control means injects fuel only from the second fuel injection valve means to perform uniform combustion. The abnormality display means causes the display device to display an abnormality indicating that an abnormality has occurred in the fuel injection system of the first fuel injection valve means.

Therefore, according to the present invention as set forth in claims 1 and 2, when some abnormality occurs in the fuel injection system of the first fuel injection valve means and the injection of high pressure fuel becomes impossible. Can continue operating the engine and notify the driver of the occurrence of the abnormality.

[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]

DESCRIPTION OF SYMBOLS 1 engine 2 intake pipe 3 air cleaner 4 air flow meter 5 throttle valve 6 exhaust pipe 7 catalytic converter 8 muffler 10 electronic control unit 10a, 10b A / D converter 10c waveform shaping circuit 10d, 10e, 10f drive circuit 10g combustion method selecting means 10h stratified layer Combustion fuel injection control means 10i 2-zone combustion fuel injection control means 10j Uniform combustion fuel injection control means 10k Abnormality determination means 10l Abnormality display means 11 In-cylinder injector (first fuel injection valve means) 12-port injection injector ( Second fuel injection valve means) 13 Crank angle sensor 14 In-cylinder pressure sensor (abnormality detection means) 15 Display device

Claims (3)

[Claims] 1. A fuel injection engine for a vehicle, in which a fuel injection valve is controlled based on an engine operating state to perform stratified combustion in an engine low / medium load operating region and to uniformly burn in an engine high load operating region, in a combustion chamber, high pressure fuel is used. Fuel injection valve means for directly injecting fuel, second fuel injection valve means for injecting low-pressure fuel into the intake system, and abnormality detection means for detecting abnormality of the fuel injection system of the first fuel injection valve means And an abnormality determination means for determining the presence or absence of an abnormality based on the detection signal of the abnormality detection means, and an abnormality display means for causing the display device to display an abnormality by the input of the abnormality determination signal from the abnormality determination means, the engine speed and the engine load. Based on the above, the stratified charge combustion method is selected in the engine low and medium load operation area, and the uniform combustion method is selected in the engine high load operation area. Selection means for uniformly selecting the uniform combustion method regardless of the engine load operation range, and fuel is injected only from the first fuel injection valve means when the stratified combustion method is selected, and the second combustion method is selected when the uniform combustion method is selected. A fuel injection engine control device for a vehicle, comprising: a fuel injection control means for injecting fuel only from the fuel injection valve means. 2. A fuel injection engine for a vehicle, which controls a fuel injection valve based on an engine operating state to perform stratified combustion in an engine low / medium load operating region and uniformly burn in an engine high load operating region, in which a high pressure fuel is contained in a combustion chamber. Fuel injection valve means for directly injecting fuel, second fuel injection valve means for injecting low-pressure fuel into the intake system, and abnormality detection means for detecting abnormality of the fuel injection system of the first fuel injection valve means And an abnormality determination means for determining whether or not there is an abnormality based on the detection signal of the abnormality detection means, and an abnormality display means for causing the display device to display an abnormality by inputting the abnormality determination signal from the abnormality determination means, the engine speed and the engine load. Based on the above, the stratified charge combustion method is selected in the engine low and medium load operation area, and the two-zone combustion method with both stratified combustion and uniform combustion is selected in the engine intermediate load operation area. In the engine high load operation range, the uniform combustion method is selected.When the above abnormality judgment signal is input, the uniform combustion method is uniformly selected regardless of the engine load operation range. The fuel is injected only from the first fuel injection valve means, the fuel injection amount is shared when the two-zone combustion system is selected, and the fuel is injected from the second fuel injection valve means immediately before the intake stroke. Fuel injection control means for injecting fuel from the first fuel injection valve means in the latter stage of the compression stroke and injecting fuel only from the second fuel injection valve means immediately before the intake stroke when the uniform combustion system is selected. A control device for a fuel injection engine for a vehicle, comprising: 3. The in-cylinder pressure sensor capable of detecting a change in in-cylinder pressure according to a fuel injection state of the first fuel injection valve means, wherein the abnormality detecting means is a cylinder pressure sensor.
A controller for a fuel injection engine for a vehicle as described above.