JP3319311B2 - Intake control device for stratified combustion internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control system for a stratified combustion internal combustion engine, and more particularly, to a swirl control valve which is opened and closed so that a fuel mixture can form a vortex at least when performing stratified combustion. The present invention relates to an intake control device for a stratified combustion internal combustion engine provided.

[0002]

2. Description of the Related Art In a conventionally used engine, fuel from a fuel injection valve is injected into an intake port, and a homogeneous mixture of fuel and air is supplied to a combustion chamber in advance. In such an engine, an intake passage is opened and closed by a throttle valve linked to an accelerator operation, and by this opening and closing, the amount of intake air supplied to a combustion chamber of the engine (consequently, a gas mixture in which fuel and air are homogeneously mixed). ) Is adjusted, thereby controlling the engine output.

[0003] However, in the technique based on the so-called homogeneous combustion described above, a large intake negative pressure is generated in accordance with the throttle operation of the throttle valve, and the pumping loss increases to lower the efficiency. On the other hand, by reducing the throttle of the throttle valve and supplying fuel directly to the combustion chamber, a combustible mixture is present near the ignition plug, and the air-fuel ratio of the portion is increased,
There is known a so-called "stratified combustion" technique for improving ignitability.

In the technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-93943, "stratified combustion" is performed by forming a vortex in a mixture of injected fuel. In this technology, a swirl control valve (S
By adjusting the opening of CV), the intensity of the vortex (swirl) is controlled. Further, according to the technology described in the publication, control is performed to retard the ignition timing and the fuel injection timing in order to prevent misfire when the engine is cold.

[0005]

However, in the technology described in the above-mentioned conventional publication, the following problems may occur. That is, the SCV opening and the swirl strength vary among the engines. There are also differences in the degree of clearance between the intake passage and the SCV between individual engines, variations in fuel spray, and variations in requirements for swirl. For this reason, the fluctuation of the engine output (torque) may be worsened, and in some cases, a problem such as misfire may occur.

[0006] In particular, when performing stratified combustion in which the interval between fuel injection and ignition is short, an appropriate swirl is required to assist in diffusion and evaporation of the fuel. The present invention has been made in view of the above-described circumstances, and an object thereof is to perform stratified combustion and to provide an intake control device for a stratified combustion internal combustion engine including a swirl control valve.
It is an object of the present invention to provide an intake control device for a stratified combustion internal combustion engine that can prevent deterioration of torque fluctuation and occurrence of misfire.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, as shown in FIG. 1, an operating state for detecting an operating state of an internal combustion engine M1 capable of performing stratified combustion is provided. when performing the detecting means M2, the previous SL stratified charge combustion, the swirl control valve M3 fuel mixture are opened and closed so that can form a vortex, an actuator M4 for driving the swirl control valve M3, the driving state detecting means An instruction opening calculating means M5 for calculating an instruction opening of the swirl control valve M3 based on the detection result of M2, and the actuator M4 is controlled based on the instruction opening calculated by the instruction opening calculating means M5. A swirl control means M6 for controlling the degree of the swirl by controlling the opening of the swirl control valve M3. In the intake control device of the stratified charge combustion engine, the maximum for the output fluctuation of the internal combustion engine M1
Output fluctuation detecting means M7 for detecting a value and an average value ;
Most of the detected output variation at the output fluctuation detecting means M7
When the large value exceeds a predetermined value, the intensity of the vortex is weakened.
While the instruction opening is corrected to increase as much as possible, the output
The maximum value of the output fluctuation detected by the fluctuation detecting means M7 is
The specified value does not exceed the specified value and the average value of the output
If it exceeds the bell, it is necessary to increase the strength of the vortex.
The gist of the invention is to include an opening correction means M8 for correcting the instruction opening to the decreasing side .

According to a second aspect of the present invention, in the intake control apparatus for a stratified combustion internal combustion engine according to the first aspect,
If the maximum value of the output fluctuation detected by the output fluctuation detecting means M7 exceeds a predetermined value and the average value of the output fluctuation exceeds a predetermined level, an EG for adjusting the exhaust gas recirculation amount is used.
While the opening of the R valve is controlled to decrease by a predetermined value, the maximum value of the output fluctuation detected by the output fluctuation detecting means does not exceed the predetermined value, and the average value of the output fluctuation is a predetermined level. Control means for controlling the opening degree of the EGR valve by a predetermined value to increase the opening degree,
The correct means is the output fluctuation detected by the output fluctuation detecting means.
If the average value of
The gist is to execute the increase correction for the degree .

[0009]

[0010]

[0011]

(Operation) According to the first aspect of the present invention, as shown in FIG. 1, the operating state of the internal combustion engine M1 capable of performing stratified combustion is detected by the operating state detecting means M2. Further, when the pre-Symbol stratified charge combustion, the opening and closing the swirl control valve M3 is, thereby fuel mixture to form a vortex, it can achieved improvement in ignitability. The swirl control valve M3 is driven by an actuator M4.

The command opening calculating means M5 calculates the command opening of the swirl control valve M3 based on the detection result of the operating state detecting means M2. Based on the calculated command opening, the vortex control means M6 calculates the command opening. The actuator M4 is controlled. By this control, the degree of opening of the swirl control valve M3 is controlled, thereby controlling the intensity of the vortex.

By the way, the swirl control valve M
3 and the strength of the vortex, the internal combustion engine M
There is a variation between one. Further, each internal combustion engine M1
There is also a difference in the degree of clearance between the intake passage and the swirl control valve M3, a variation in fuel spray, and a variation in requirements for eddy currents. Therefore, the output of the internal combustion engine M1 may fluctuate. On the other hand, in the present invention, the maximum value and the average value of the output fluctuation of the internal combustion engine M1 are determined.
An average value is detected by the output fluctuation detecting means M7.
Then, the maximum value of the detected output fluctuation and the average
The indicated opening is corrected by the opening correction means M8 based on the value . Specifically, the maximum value of the output fluctuation is equal to a predetermined value.
If it exceeds, increase the indicated opening to weaken the strength of the vortex.
While being corrected to the large side, the maximum value of the output fluctuation exceeds the predetermined value.
And the average value of the output fluctuation exceeds a predetermined level.
If necessary, reduce the indicated opening to increase the strength of the vortex.
Corrected to the side. For this reason, the opening degree of the swirl control valve M3, and further, the eddy current is optimized.

That is, when the maximum value of the output fluctuation exceeds a predetermined value, the indicated opening degree is corrected to the increasing side .
Because, it is assumed intensity of swirl is small, it is possible to suppress a sudden misfire can occur when the strength of the vortex is greater.

Further, the maximum value of the output fluctuation exceeds a predetermined value.
And the average value of the output fluctuation exceeds the predetermined level.
In this case, the indicated opening is corrected to decrease,
Becomes stronger, and the output fluctuation is reduced.
Therefore, it is possible to suppress the deterioration of the driving feeling and the decrease in the torque level due to the high output fluctuation.

[0017] According to the invention described in claim 2, in addition to the functions of the invention as set forth in claim 1, the improvement of the combustion state及
Torque fluctuation and increase torque fluctuation.
Reduction of exhaust emissions and fuel
You can aim up.

[0018]

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, a first embodiment of an intake control device for a stratified combustion internal combustion engine according to the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic diagram showing an intake control device for a direct injection engine mounted on a vehicle in the present embodiment. The engine 1 as an internal combustion engine is, for example, 4
Three cylinders 1a are provided, and the combustion chamber structure of each of the cylinders 1a is shown in FIG. As shown in these drawings, the engine 1 includes a piston in a cylinder block 2, and the piston reciprocates in the cylinder block 2. A cylinder head 4 is provided above the cylinder block 2, and a combustion chamber 5 is formed between the piston and the cylinder head 4. In the present embodiment, 1
Four valves are arranged per cylinder 1a. In the figure, a first intake valve 6a, a second intake valve 6b, a first intake port 7a, a second intake port 7b, and a pair 8 A pair of exhaust ports are shown as exhaust valves 9 respectively.

As shown in FIG. 3, the first intake port 7a
Is composed of a helical intake port, and the second intake port 7
b consists of a straight port extending almost straight.
In addition, an ignition plug 10 is disposed at the center of the inner wall surface of the cylinder head 4. Further, a fuel injection valve 11 as a fuel injection means is disposed around the inner wall surface of the cylinder head 4 near the first intake valve 6a and the second intake valve 6b. That is, in the present embodiment, the fuel from the fuel injection valve 11 is directly injected into the cylinder 1a.

As shown in FIG. 2, the first intake port 7a and the second intake port 7b of each cylinder 1a are respectively connected via a first intake path 15a and a second intake path 15b formed in each intake manifold 15. Connected to the surge tank 16. A swirl control valve 17 is arranged in each second intake passage 15b. These swirl control valves 17 are connected via a common shaft 18 to a step motor 19 as an actuator. The step motor 19 is controlled based on an output signal from an electronic control unit (hereinafter simply referred to as “ECU”) 30 described later.

The surge tank 16 includes an intake duct 20
Is connected to the air cleaner 21 through the intake duct 20.
Inside, a throttle valve 23 which is opened and closed by a separate step motor 22 is provided. That is, the throttle valve 23 of this embodiment is of a so-called electronic control type, and basically, the step motor 22 is
The throttle valve 23 is opened and closed by being driven based on the output signal from 0. By opening and closing the throttle valve 23, the amount of intake air introduced into the combustion chamber 5 through the intake duct 20 is adjusted. In the present embodiment, the intake duct 20, the surge tank 16, the first intake path 15a and the second intake path 15
The intake passage is constituted by b and the like. In addition, near the throttle valve 23, its opening (throttle opening T
A throttle sensor 25 for detecting A) is provided. An exhaust manifold 14 is connected to the exhaust port 9 of each cylinder. The exhaust gas after combustion is discharged to an exhaust duct (not shown) via the exhaust manifold 14.

Further, in this embodiment, a known exhaust gas circulation (EGR) device 51 is provided. This EG
The R device 51 includes an EGR passage 5 as an exhaust gas circulation passage.
2 and an EGR valve 53 as an exhaust gas circulation valve provided in the middle of the passage 52. EGR passage 5
2 is an intake duct 20 downstream of the throttle valve 23;
It is provided so as to communicate with the exhaust duct. Further, the EGR valve 53 has a built-in valve seat, valve body, and step motor (all not shown), and these constitute an EGR mechanism. The opening degree of the EGR valve 53 fluctuates when the stepping motor intermittently displaces the valve body with respect to the valve seat. And the EGR valve 5
When the valve 3 opens, a part of the exhaust gas discharged to the exhaust duct flows to the EGR passage 52. The exhaust gas is
It flows to the intake duct 20 via the EGR valve 53. That is, a part of the exhaust gas is recirculated into the intake air-fuel mixture by the EGR device 51. At this time, the recirculation amount of the exhaust gas is adjusted by adjusting the opening degree of the EGR valve 53.

The above-described ECU 30 is composed of a digital computer, and is connected to a RAM (random access memory) 3 via a bidirectional bus 31.
2, a ROM (Read Only Memory) 33, a CPU (Central Processing Unit) 34 composed of a microprocessor, an input port 35 and an output port 36. In the present embodiment, the ECU 30 constitutes an instruction opening calculation unit, an eddy current control unit, and an opening correction unit.

An accelerator sensor 26A for generating an output voltage proportional to the amount of depression of the accelerator pedal 24 is connected to the accelerator pedal 24.
Accelerator opening ACCP is detected by 6A. The output voltage of the accelerator sensor 26A is input to the input port 35 via the AD converter 37. Similarly, the accelerator pedal 24 has a fully-closed switch 26B for detecting that the depression amount of the accelerator pedal 24 is "0".
Is provided. That is, the fully closed switch 26B
Generates a signal of "1" as the fully closed signal when the depression amount of the accelerator pedal 24 is "0", and generates a signal of "0" otherwise. And the fully closed switch 26
The output voltage of B is also input to the input port 35.

The top dead center sensor 27 generates an output pulse when the first cylinder 1a reaches the intake top dead center, for example.
This output pulse is input to the input port 35. The crank angle sensor 28 has a crankshaft of 30 ° CA, for example.
An output pulse is generated each time the motor rotates, and the output pulse is input to the input port. In the CPU 34, the top dead center sensor 2
7 and the output pulse of the crank angle sensor 28, the engine speed NE is calculated (read).

Further, the rotation angle of the shaft 18 is
The swirl control valve sensor 29 detects the swirl control valve (SCV).
Seventeen opening degrees are detected. The output of the swirl control valve sensor 29 is input to the input port 35 via the A / D converter 37.

At the same time, the throttle sensor 25 detects the throttle opening degree TA. The output of the throttle sensor 25 is input to an input port 35 via an A / D converter 37.

In addition, in the present embodiment, an intake pressure sensor 61 for detecting the pressure (intake pressure PIM) in the surge tank 16 is provided. Further, a water temperature sensor 62 that detects the temperature of the cooling water of the engine 1 (cooling water temperature THW) is provided. The output of both sensors 61 and 62 is also A /
The data is input to the input port 35 via the D converter 37.

In the present embodiment, the throttle sensor 25, the accelerator sensor 26A, the fully closed switch 26
B, a top dead center sensor 27, a crank angle sensor 28, a swirl control valve sensor 29, an intake pressure sensor 61, a water temperature sensor 62, and the like constitute an operating state detecting means.

The crank angle sensor 28, the ECU 30
Thus, output fluctuation detecting means is constituted. On the other hand, the output port 36 is connected to each fuel injection valve 11, each step motor 19, 22, the igniter 12, and the EGR valve 53 (step motor) via the corresponding drive circuit 38. Then, the ECU 30 includes the sensors 25 to 2 and the like.
In accordance with the control program stored in the ROM 33, the fuel injection valve 11, the step motors 19 and 22, the igniter 12, the EGR valve 53 and the like are suitably controlled based on the signals from 9, 61 and 62.

Next, a program relating to various controls according to the present embodiment in the intake control device for an engine having the above configuration will be described with reference to a flowchart. That is, FIG. 4 is a flowchart showing an “SCV control routine” for performing intake control, particularly SCV control during stratified combustion, in the present embodiment, and is executed, for example, by interruption every predetermined crank angle. .

When the processing shifts to this routine, the ECU
First, in step 101, the torque decrease amount dln for each predetermined crank angle (for example, “720 ° CA”) is set.
Is calculated. Here, the torque decrease amount dln is defined as
It is expressed as a difference between the rotation speed of the engine 1 detected by the crank angle sensor 28 and the rotation speed of the engine 1 after a predetermined rotation (for example, “90 ° CA” rotation). From the square of the angular velocity of engine 1
It is calculated by subtracting the square of the angular velocity of the engine 1 after the 0 ° CA rotation.

Next, in step 102, the torque decrease amount dln during the predetermined rotation of the engine 1 is determined.
The maximum value dlnmax and the average value dlnmean are calculated.

Further, in step 103, the maximum value dlnmax of the torque reduction amount dln calculated this time is obtained.
Is greater than a preset misfire determination level dlnlvlmx. Then, the torque reduction amount d
The maximum value dlnmax of ln is the misfire determination level dlnlv
If it is larger than lmx, it is determined in step 104 that the maximum value dlnmax is large because the difference between the rotational speeds during combustion and misfire is large, and the misfire has occurred. Misfire is determined.

Further, in the following step 105,
A predetermined value Cs with respect to the previous target SCV opening scvrat
Is set as a new target SCV opening scvrat. As a result, the opening of the SCV 17 increases, and the swirl strength is reduced.

Finally, in step 106,
The count value cdlnlvl of the counter is cleared to "0", and the subsequent processing is temporarily terminated. On the other hand, in step 103, the maximum value dlnm of the torque reduction amount dln
If ax is not higher than the misfire determination level dlnlvlmx, the process proceeds to step 107. Then, at step 107, the count value cdlnl of the counter
Increment vl by "1".

Further, in step 108, it is determined whether or not the count value cdlnlvl of the counter has passed a predetermined time C1. If the predetermined time C1 has not yet passed, the subsequent processing is temporarily terminated without performing any processing.

On the other hand, the count value cdl of the counter
If nlvl has exceeded the predetermined time C1, it is determined that there has been no misfire for some time and the combustion state is not unstable, and a determination of "no misfire" is made in step 109.

Further, in the following step 110,
Average value dlnme of torque reduction amount dln calculated this time
an is the target value dlnlv10 of the average torque fluctuation (FIG. 5).
Is determined to be larger than the above. And
If the average value dlnmean is not larger than the target value dlnlv10, it is determined that the opening of the SCV 17 is within the control range, and the subsequent processing is temporarily terminated without performing any processing.

The average value dlnmean is equal to the target value dl.
If it is larger than nlvl0, it is determined that it is necessary to reduce the average value of the torque fluctuation to improve the driving feeling, and the process proceeds to step 111. In step 111, the ECU 30 sets a value obtained by subtracting the predetermined value Cs from the previous target SCV opening scvrat as a new target SCV opening scvrat. As a result, the opening of the SCV 17 is reduced, and the swirl strength is increased.

Finally, in step 112,
The count value cdlnlvl of the counter is cleared to "0", and the subsequent processing is temporarily terminated. Next, the operation and effect of the present embodiment will be described with reference to FIG.

(A) As described in the prior art, the actual opening of the SCV 17 and the swirl strength are:
There are variations among the individual engines 1. There are also differences in the degree of clearance between the intake passage and the SCV 17 between the individual engines 1, variations in fuel spray, and variations in requirements for eddy currents. Therefore, the output of the engine 1 may fluctuate due to these factors. On the other hand, in the present embodiment, when the maximum value dlnmax of the torque decrease amount dln is larger than the misfire determination level dlnlvlmx, it is determined that there is a misfire, and the target SC is determined.
The V-opening scvrat was increased.

Therefore, as shown in FIG. 5, the opening of the SCV 17 increases, and the swirl strength is reduced. As a result, a sudden misfire can be prevented from occurring, as shown in the middle part of the figure.

(B) In this embodiment, the average value dlnmean of the torque reduction amount dln is equal to the target value dlnlv.
If it is larger than 10, the target SCV opening scvr
t was reduced. For this reason, the opening of the SCV 17 decreases, and the strength of the swirl is increased. As a result, as shown in the upper part of the figure, the average value of the torque fluctuation is reduced, so that the driving feeling can be improved.

Further, accompanying this, it is also possible to suppress a decrease in the overall torque due to the opening of the SCV 17 being too large (lower part in the figure). (Second Embodiment) Next, a second embodiment of the present invention will be described. However, since the configuration and the like of this embodiment are the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the differences from the first embodiment.

In this embodiment, not only the SCV 17 but also the EGR valve 53 is controlled.
Is different from the embodiment. That is, FIG. 6 shows “SCV · E” for performing intake control in the present embodiment, in particular, SCV control and EGR control during stratified combustion.
Is a flowchart showing a "GR control routine", which is executed, for example, by interruption every predetermined crank angle.

When the processing shifts to this routine, the ECU
First, at step 201, a predetermined crank angle (for example, “720 ° C.
A ") Calculate the torque decrease amount dln for each).

Next, at step 202, the torque decrease amount dln during the predetermined rotation of the engine 1 is obtained.
The maximum value dlnmax and the average value dlnmean are calculated.

Further, in step 203, the maximum value dlnmax of the torque reduction amount dln calculated this time is obtained.
Is greater than a preset misfire determination level dlnlvlmx. Then, the torque reduction amount d
The maximum value dlnmax of ln is the misfire determination level dlnlv
If it is larger than 1mx, the process proceeds to step 204.

In step 204, the average value dlnmean of the torque reduction amount dln calculated this time may be the same as the target value dln0 of the average torque fluctuation (the target value dlnlv10 of the first embodiment, Is determined to be smaller than (may be different).
If the average value dlnmean is not smaller than the target value dln0, it is determined in step 205 that the average torque fluctuation is poor and misfire has occurred, and then the process proceeds to step 206.

In step 206, the prior target E is set so as to give priority to the reduction of the EGR amount over the swirl intensity.
A value obtained by subtracting a predetermined value Ce from the GR opening EGR is set as a new target EGR opening EGR. Then, the subsequent processing ends once.

If it is determined in step 204 that the average value dlnmean of the torque decrease amount dln is smaller than the target value dln0 of the average torque fluctuation, the process proceeds to step 207. In step 207, it is determined that the misfire has occurred although the average torque fluctuation is good, and the process proceeds to step 208. In step 208, a value obtained by adding a predetermined value Cs to the previous target SCV opening scvrat is used as a new target SCV opening scvrat.
Set as As a result, the opening of the SCV 17 increases, and the swirl strength is reduced.

On the other hand, if the maximum value dlnmax of the torque reduction amount dln is not larger than the misfire determination level dlnlvlmx in step 203, the process proceeds to step 209. Then, in step 209,
Average value dlnme of torque reduction amount dln calculated this time
It is determined again whether an is smaller than the target value dln0 of the average torque fluctuation. And the average value dlnmean
Is smaller than the target value dln0, step 21
0, it is determined that the average torque fluctuation is good and no misfire has occurred.
Move to 11.

In step 211, EGR is performed for the purpose of reducing exhaust emissions and improving fuel efficiency.
In order to increase the amount, the previous target EGR opening EGR
The value obtained by adding the predetermined value Ce is used as a new target EGR opening degree EGR.
Set as Then, the subsequent processing ends once.

If it is determined in step 209 that the average value dlnmean of the torque reduction amount dln is not smaller than the target value dln0 of the average torque fluctuation, the process proceeds to step 212. In step 212, the average value dlnmean of the torque reduction amount dln is further calculated as follows:
It is determined whether or not the value is greater than a value obtained by adding a predetermined value CL to the target value dln0 of the average torque fluctuation. The average value dlnmean is equal to the target value dln0 of the average torque fluctuation.
Is larger than the value obtained by adding the predetermined value CL to
In step 213, it is determined that the average torque fluctuation is bad, but no misfire has occurred, and the routine proceeds to step 214.

In step 214, the previous target S
A value obtained by subtracting a predetermined value Cs from the CV opening scvrat is set as a new target SCV opening scvrat. As a result, the opening of the SCV 17 is reduced, and the swirl strength is increased.

If it is determined in step 212 that the average value dlnmean of the torque reduction amount dln is not as large as the value obtained by adding the predetermined value CL to the target value dln0 of the average torque fluctuation, no processing is performed. Then, the subsequent processing is temporarily ended.

Next, the operation and effect of this embodiment will be described. (A) Also in this embodiment, basically, the first
Almost the same effects as those of the embodiment can be obtained. Also,
In addition to this, the average value dlnme of the torque reduction amount dln
If an is greater than or equal to the target value dln0, it is determined that the average torque fluctuation is poor and misfire has occurred. In this case, the prior art is given priority over reducing the EGR amount over the swirl intensity. A value obtained by subtracting the predetermined value Ce from the target EGR opening EGR is set as a new target EGR opening EGR. Therefore, the combustion state is improved, and the torque fluctuation can be further reduced.

(B) If the average value dlnmean of the torque reduction amount dln is smaller than the target value dln0, it is determined that the average torque fluctuation is good and no misfire has occurred. A value obtained by adding a predetermined value Ce to the previous target EGR opening degree EGR is used as a new target EGR.
The opening degree EGR is set to increase the EGR amount. Therefore, it is possible to reduce exhaust emissions and improve fuel efficiency within a range that does not cause an increase in torque fluctuation.

The present invention is not limited to the above embodiments, and may be configured as follows, for example. (1) In the second embodiment, the SCV 17 and the EGR
Although the case where the control with the valve 53 is combined has been embodied, the control of the fuel injection amount may be combined with this. For example, the average value dl of the torque decrease amount dln
When nmean is smaller than the target value dln0, E
Although the GR amount is increased, the fuel injection amount may be reduced by a predetermined amount in this case. By performing such control, fuel efficiency can be further improved. Conversely, the average value dln of the torque reduction amount dln
When the mean is equal to or more than the target value dln0, the EGR amount is reduced. In this case, the fuel injection amount may be increased by a predetermined amount. By performing such control, torque fluctuation can be more positively suppressed.

(2) The EGR control is omitted, and the SCV
A case in which the control of the fuel injection amount 17 and the control of the fuel injection amount are combined can be embodied. (3) In the above embodiment, the present invention is embodied in the in-cylinder injection type engine 1, but may be embodied in a so-called general stratified combustion or weak stratified combustion type. . For example, the intake valves 6 of the intake ports 7a and 7b
a and 6b include those of the type that sprays toward the back side of the umbrella portion. Although a fuel injection valve is provided on the intake valves 6a and 6b side, a type in which fuel is injected directly into the cylinder bore (combustion chamber 5) is also included. Further, the present invention can also be embodied in an engine capable of performing lean combustion and stoichiometric combustion, which are higher concepts.

(4) In each of the above embodiments, the present invention is embodied in the case of the gasoline engine 1 as the internal combustion engine. However, the present invention can be embodied in the case of a diesel engine or the like.

[0065]

[0066]

[0067]

As described in detail above, according to the present invention,
In the intake control device for a stratified combustion internal combustion engine equipped with a swirl control valve, it is possible to perform stratified combustion and to achieve an excellent effect that deterioration of torque fluctuation and occurrence of misfire can be prevented.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram showing a basic concept of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an intake control device for a stratified combustion engine according to the first embodiment.

FIG. 3 is an enlarged sectional view showing a cylinder portion of the engine.

FIG. 4 is a flowchart showing an “SCV control routine” executed by the ECU.

FIG. 5 is a graph showing the relationship between the average torque fluctuation, the number of misfires, and the torque with respect to the SCV opening.

FIG. 6 is a flowchart illustrating an “SCV / EGR control routine” executed by an ECU according to the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 11 ... Fuel injection valve, 1
7: swirl control valve, 19: step motor as actuator, 25: throttle sensor constituting operating state detecting means, 26A: accelerator sensor constituting operating state detecting means, 26B ... fully closed switch constituting operating state detecting means , 27 ... Top dead center sensor forming operating state detecting means, 28 ... Crank angle sensor forming operating state detecting means, 29 ... Swirl control valve sensor forming operating state detecting means, 30 ... Command opening calculating means, ECU constituting the eddy current controlling means, the opening degree correcting means, and the output fluctuation detecting means, 53... EGR valve, 6
1. Intake pressure sensor constituting operating state detecting means, 62 ...
A water temperature sensor constituting an operating state detecting means.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02M 25/07 570 F02M 25/07 570A 69/00 360 69/00 360C (56) References JP-A-6-101518 (JP, A) JP-A-6-93943 (JP, A) JP-A-62-17319 (JP, A) JP-A-61-201822 (JP, A) JP-A-61-169615 (JP, A) JP, U) JP-A-3-87827 (JP, U) JP-A-61-167427 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02B 31/02

Claims (2)

(57) [Claims] And 1. A driving state detecting means for detecting an operating condition of the internal combustion engine which can perform stratified charge combustion, when performing pre-Symbol stratified charge combustion, the swirl control valve fuel mixture are opened and closed so that can form a vortex An actuator that drives the swirl control valve; an instruction opening calculation unit that calculates an instruction opening of the swirl control valve based on a detection result of the operating state detection unit; A swirl control means for controlling the intensity of the swirl by controlling the actuator to control the opening of the swirl control valve based on the indicated opening degree, the intake control apparatus for a stratified combustion internal combustion engine comprising: The maximum value and the average value of the output fluctuation of the internal combustion engine
Output fluctuation detecting means for detecting a proper value, and a maximum value of the output fluctuation detected by the output fluctuation detecting means.
If the value exceeds a predetermined value, the intensity of the vortex should be reduced.
While the command opening is corrected to the increasing side, the output fluctuation
The maximum value of the output fluctuation detected by the detection means exceeds a predetermined value.
And the average value of the output fluctuation exceeds a predetermined level.
If it is possible to increase the intensity of the eddy current,
And an opening correction means for correcting the degree to a decreasing side . 2. The intake control device for a stratified combustion internal combustion engine according to claim 1, wherein the maximum value of the output fluctuation detected by the output fluctuation detecting means exceeds a predetermined value, and If the value exceeds a predetermined level, the opening of the EGR valve for adjusting the exhaust gas recirculation amount is controlled to decrease by a predetermined value, while the maximum value of the output fluctuation detected by the output fluctuation detecting means is changed to a predetermined value. And when the average value of the output fluctuation does not exceed a predetermined level, a control means for controlling the opening of the EGR valve by a predetermined value to an increasing side is provided , and the opening correction means comprises: Detected by output fluctuation detection means
If the average value of the output fluctuation does not exceed the specified level
An intake control device for a stratified combustion internal combustion engine, wherein the increase correction is performed on the command opening .