JP2001323833A - Control device for premixing compression self ignition engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a premixing compression self-ignition engine capable of leveling the dispersion of the combustion performance of every cylinder in the premixing compression self-ignition engine having plural cylinders, stabilizing combustion to enhance the startability or operational controllability as a whole of the engine, and stably, efficiently operating. SOLUTION: A sensor 6 for detecting a combustion state is installed every cylinder 1, the control device 5 judges whether the self-ignition is good or not every cylinder 1 based on a signal of the sensors 6, increases the supply of fuel when the self-ignition is no good, judges whether knocking is present or not, and decreases the supply of fuel when the knocking is present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a homogeneous charge compression ignition engine having a plurality of cylinders (a homogeneous charge compression ignition multi-cylinder engine), and more particularly to equalizing combustion performance variation among cylinders. The present invention relates to a control device for improving startability and performance of an entire engine.

[0002]

2. Description of the Related Art A premixed compression ignition engine, which is an internal combustion engine in which a premixed gas is supplied into a cylinder and self-ignites and burns at a high compression ratio, is in a state of a supplied mixture, for example, a fuel concentration (and its distribution). , Temperature, pressure, etc., the combustion performance, such as ignitability (including startability), ignition timing, combustion speed (pressure rise rate)
And so on, which tend to cause delicate influences and cause unstable combustion, which is very difficult to control. In particular, in a multi-cylinder engine having a plurality of cylinders, the above-described parameters vary from cylinder to cylinder, thereby deteriorating the startability and drivability of the entire engine, and hindering stable and efficient operation. Problem.

[0003]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems of the prior art, and it has been proposed to level out the variation in the combustion state between the cylinders of a multi-cylinder engine.
To provide a control device for a homogeneous charge compression ignition engine that stabilizes combustion, thereby improving the startability and operation controllability of the multi-cylinder engine as a whole and performing stable and highly efficient operation. It is an object.

[0004]

A control apparatus for a homogeneous charge compression ignition engine according to the present invention is a control apparatus for a homogeneous charge compression ignition engine having a plurality of cylinders (a homogeneous charge compression ignition multi-cylinder engine). A sensor that detects a combustion state is provided for each cylinder of the engine, and the control device determines whether the self-ignition property is good or bad from the signal of the sensor for each cylinder, and when the self-ignition property is poor, The system is configured to increase the fuel supply amount, determine whether knocking is present, and perform control to reduce the fuel supply amount when knocking is present. In practicing the present invention, it is preferable to provide a fuel supply means whose supply amount is adjustable.

According to the present invention having such a configuration,
The combustion state is detected by a sensor for each cylinder (cylinder). If the ignitability of the cylinder is poor, the ignitability is improved by increasing the fuel supply. Further, if it is detected that knocking has occurred in the cylinder, knocking is suppressed by a decrease in fuel supply. And
By performing these controls on a cylinder-by-cylinder basis, variations between cylinders in self-ignition combustion are leveled out, and a stable and highly efficient operation of the entire engine can be performed.

A control device for a homogeneous charge compression ignition engine according to the present invention is a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state for each cylinder of the engine is provided. The control device determines whether the self-ignition property is good or bad by the sensor for each cylinder, supplies the self-ignition accelerator when the self-ignition property is poor, and further determines the presence or absence of knocking. When knocking is present, control is performed to reduce the supply of the self-ignition accelerator. Here, it is preferable to provide a self-ignition accelerator supply means capable of adjusting the supply amount (of the self-ignition accelerator).

As the self-ignition accelerator, for example, NOx
And ozone are preferred.

A control device for a homogeneous charge compression ignition engine according to the present invention is a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine. The control device determines the ignitability of each cylinder by the sensor, supplies an auto-ignition inhibitor in the case of premature ignition, further determines the stability of combustion, and determines the combustion. When unstable, the control is performed to reduce the supply of the self-ignition inhibitor. And it is preferable to provide a self-ignition inhibitor supply means capable of adjusting the supply amount (of the self-ignition inhibitor).

The self-ignition suppressant includes CO ₂ and N
_{2 and the} like are preferred.

According to the present invention having the above-described structure, the self-ignition accelerator is supplied to each cylinder when the self-ignition property is determined to be poor, while the self-ignition is supplied to the respective cylinders when knocking is determined. Reduce the supply of accelerators. Alternatively, the self-ignition inhibitor is supplied to each cylinder when it is determined to be premature ignition, while the supply of the self-ignition inhibitor is reduced when it is determined to be unstable. By performing such control, the variation of the premixed compression auto-ignition combustion among the cylinders is leveled, and the combustion is stabilized as a whole multi-cylinder engine, and therefore, the stable operation as a whole engine is performed. .

Further, a control device for a homogeneous charge compression ignition engine according to the present invention is a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine. At the same time, an intake flow rate adjusting means is provided in an intake path to each cylinder, and the control device includes:
The combustion state is determined by the sensor for each cylinder,
When it is determined that the combustion state is unstable, the intake air flow rate is decreased, and when it is determined that knocking has occurred, the intake air flow rate is increased.

Alternatively, a control device for a homogeneous charge compression ignition engine according to the present invention is a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine. In addition, an intake heating means is provided in an intake path to each cylinder, and the control device determines the combustion state by the sensor for each cylinder, and when it is determined that the combustion state is unstable, the intake heating is performed. The amount is increased (or intake air heating is started), and when it is determined that knocking has occurred, the intake air heating amount is reduced (or intake air heating is stopped). .

As the intake air heating means, an electric heater, a heat exchanger between exhaust air and intake air, and the like are preferable. Alternatively, the intake air heating means includes a branch passage that supplies the high-temperature supercharged air immediately after passing through the supercharger to the intake passage (for each cylinder) by bypassing the intercooler, and an opening / closing unit that opens and closes the branch passage. Preferably, the opening / closing means is configured to be opened / closed by the control device.

In the present invention, the combustion state is detected for each cylinder,
If unstable, the intake air flow rate is reduced, and if knocking has occurred, the intake air flow rate is increased. Alternatively, the intake air heating amount is increased in the case of instability, and the intake air heating amount is decreased in the case of knocking. By performing such control, the combustion is stabilized for each cylinder, the variation in the self-ignition combustion between the cylinders is leveled, and the stable operation of the entire multi-cylinder engine is performed.

A control device for a homogeneous charge compression ignition engine according to the present invention is a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine. At the same time, an exhaust gas recirculation path (E
(GR flow path), the control device determines the combustion state by the sensor for each cylinder, and when it is determined that the combustion state is unstable, the exhaust gas recirculation amount (EGR amount)
Is reduced, and control is performed to increase the exhaust gas recirculation amount when it is determined that knocking has occurred.

The exhaust gas recirculation path branches off from the downstream side of the portion where exhaust from each cylinder is integrated,
Further, it is preferable that the individual mergings are individually made into the intake passages of the respective cylinders and connected via a control valve. Alternatively, the exhaust gas recirculation passage branches from each exhaust passage upstream of a portion where exhaust from each cylinder is unified, and is connected (or merged) to each intake passage via a control valve. Is preferred.

As described above, the combustion state is detected for each cylinder, and the amount of exhaust gas circulation is reduced in the case of instability, and the amount of exhaust gas circulation is increased in the case of knocking, thereby stabilizing the combustion of each cylinder. Therefore, variations in auto-ignition combustion between the cylinders are leveled, and stable operation of the entire engine can be achieved.

Here, as the sensor for detecting the combustion state, for example, an in-cylinder pressure detection sensor capable of directly measuring the pressure in the cylinder can be used. Alternatively, as a sensor for detecting the combustion state, an ion probe for measuring an ion current generated during combustion may be used.

That is, in each of the above-described inventions, the combustion state of each cylinder of the control device is determined from the combustion pressure detected by the in-cylinder pressure detection sensor and its time change,
Alternatively, by determining from the ion current detected by the ion probe and its time change, the combustion state of each cylinder can be accurately determined.

When the variation in combustion performance occurring in each cylinder of a multi-cylinder engine occurs in a specific cylinder, for example, due to a difference in the intake state between a two-end cylinder and an intermediate cylinder in a row engine. Alternatively, the detection and control of the combustion state for each cylinder as described above may be applied only to the specific cylinder (the specific cylinder in which the combustion performance varies).

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, in the illustrated embodiment, an in-line six-cylinder engine will be described as an example of a multi-cylinder engine. FIG. 1 shows a main configuration of a homogeneous charge compression ignition engine according to the present invention, in which first to sixth cylinders 1a to 1f (hereinafter, referred to as "first to sixth cylinders 1a to 1f").
An intake manifold 2 for supplying an air-fuel mixture to each of the cylinders is referred to as a cylinder, and is represented by reference numeral 1. An intake manifold 2 is provided on one side of the engine, and an exhaust pipe (FIG. (Not shown). And the intake manifold 2
A fuel supply device 7 that is controlled by the control device 5 and supplies fuel is provided on the branch path B to each of the cylinders 1. Each cylinder 1 is provided with a sensor 6 for detecting its combustion state, and a detection signal is sent to the control device 5.

The control procedure of the control device 5 will be described with reference to the flowchart of FIG. First, in step S1,
Designate the first cylinder 1a as the cylinder to be controlled (i =
1) In step S2, it is determined from the signal of the sensor 6 of the (i-th) cylinder whether or not unstable combustion has occurred. If the determination is not unstable, the process proceeds to step S6. If the determination is unstable, the process proceeds to step S3 to increase the amount of fuel supplied from the fuel supply device 7. Then, it is determined in step S4 whether knocking has occurred.
If yes, the fuel supply amount is reduced in step S5, and the flow proceeds to step S6.

In step S6, it is checked whether the controlled (i) th cylinder is the last (Nth, in this example, 6th) cylinder.
7, the next (i + 1) th cylinder is designated, and step S2
Return to If it is the last (N-th) cylinder, it is determined in step S8 whether or not the control is finished.

Next, the control procedure of the second embodiment will be described with reference to the flowchart of FIG. The configuration of this embodiment is obtained by adding a function of supplying an auto-ignition accelerator to the fuel supply device 7 of the embodiment shown in FIG.
As the self-ignition accelerator, for example, NOx, ozone, or the like is used.

First, in step S11, the first cylinder 1a is designated as the cylinder to be controlled (i = 1), and
At 12, it is determined from the signal of the sensor 6 of the (i) th cylinder whether or not unstable combustion has occurred. If it is not unstable, the process proceeds to step S16, and if it is unstable, the process proceeds to step S13 to increase the supply amount of the self-ignition accelerator. Then, it is determined in step S14 whether knocking has occurred. If No, the process proceeds to step S16. If Yes, the supply amount of the self-ignition accelerator is reduced in step S15.
Proceed to 6.

In step S16, it is checked whether the (i) th cylinder controlled is the last (Nth, in this example, 6th) cylinder. If not, the next (i + 1) th cylinder is checked in step S17. The cylinder is specified, and the process returns to step S12. If it is the last (No. N) cylinder, it is determined in step S18 whether or not the control is completed.
Returning to No. 1, the process is repeated from the first cylinder 1a.

In the third embodiment, a function of supplying a self-ignition suppressant is added to the fuel supply device 7 of the embodiment shown in FIG. In addition, as a self-ignition inhibitor, CO
Using the ₂ and _{N 2} and the like. The control procedure is shown in FIG.
In step S21, the first cylinder is set as the cylinder to be controlled.
a is designated (i = 1), and in step S22, it is determined from the signal of the sensor 6 of the (i-th) cylinder whether or not premature ignition has occurred. If No, proceed to Step S26, Yes
If so, the process proceeds to step S23 to supply the self-ignition inhibitor. Then, it is determined whether or not unstable combustion is performed in step S24. If No, the process proceeds to step S26. If Yes, the supply amount of the self-ignition inhibitor is reduced in step S25, and the process proceeds to step S26.

In step S26, it is checked whether the controlled (i) th cylinder is the last (Nth, in this example, 6th) cylinder. If not, the next (i + 1) th cylinder is checked in step S27. The cylinder is specified, and the process returns to step S22. If it is the last (No. N) cylinder, it is determined in step S28 whether or not the control is finished.
Returning to No. 1, the process is repeated from the first cylinder 1a.

Next, in a fourth embodiment shown in FIG. 5, an intake air amount adjusting valve 8 is interposed in a branch path B to each cylinder 1 of the intake manifold 2A. Numeral 8 indicates that the combustion state is determined from a signal from a sensor 6 provided for each cylinder 1 by a control device (not shown), and the opening thereof is adjusted.

The control procedure of the fourth embodiment will be described with reference to the flowchart of FIG. First, step S31
Then, the first cylinder is selected as the cylinder 1 to be controlled, and the combustion state is checked by the sensor 6 in step S32. Then, in step S33, it is determined whether the combustion state is stable, unstable, or knocking. If unstable, the intake air amount adjusting valve 8 is throttled in step S35 to reduce the intake air amount. For example, the intake air amount adjusting valve 8 is maintained as it is (step S34). If it is determined that the engine is knocking, the intake air amount adjusting valve 8 is opened to increase the amount of intake air, and the process proceeds to step S37.

In step S37, it is checked whether the controlled (i) th cylinder is the last (Nth, in this example, 6th) cylinder. If not, the next (i + 1) th cylinder is checked in step S38. The cylinder is specified, and the process returns to step S32. If the cylinder is the last (No. N) cylinder, it is determined in step S39 whether the control is completed.
Returning to No. 1, the process is repeated from the first cylinder 1a.

FIGS. 7 to 10 show an embodiment in which intake air is heated to cope with unstable combustion. In the fifth embodiment shown in FIG. 7, the electric heaters 12 are interposed in the branch paths B to the respective cylinders 1 of the intake manifold 2B, and the respective heaters 12 are controlled by a control device (not shown). The combustion state is determined from the signal of the sensor 6 provided for each cylinder, and the electric heater heating is controlled.

The control procedure of the fifth embodiment will be described with reference to the flowchart of FIG. First, step S41
Then, the first cylinder is selected as the cylinder 1 to be controlled, and the combustion state is checked by the sensor 6 in step S42. Then, in step S43, it is determined whether the combustion state is stable, unstable, or knocking. If the combustion state is unstable, the heating amount of the electric heater 12 is increased in step S45. (Step S
44) If the knocking state is determined, the electric heater 1
The heating amounts of No. 2 are reduced, and the process proceeds to step S47.

In step S47, it is checked whether the controlled (i) th cylinder is the last (Nth, in this example, 6th) cylinder. If not, the next (i + 1) th cylinder is checked in step S48. The cylinder is specified, and the process returns to step S42. If it is the last (No. N) cylinder, it is determined in step S49 whether or not the control is completed.
Returning to No. 1, the process is repeated from the first cylinder 1a.

In the sixth embodiment shown in FIG. 9, a heat exchanger 12A for exchanging heat with exhaust gas is interposed in a branch B to each cylinder 1 of the intake manifold 2B. The exhaust branch passages 14 branch from the wake where exhaust from each cylinder of the exhaust manifold 3 is integrated.
Is branched to each heat exchanger 12A, and the flow control valve 1
3, and is connected to each heat exchanger 12A.

The seventh embodiment shown in FIG. 10 is an engine provided with a turbocharger 15, in which the supply air which has been supercharged by the supercharger 15 and has become high temperature is cooled by the intercooler 16,
The air enters the intake manifold 2C, branches off, and is sent to each cylinder 1. Then, the air supply branch passages 17 (branch passages) branching from the upstream of the intercooler 16 and opening to the branch passages B to the respective cylinders of the intake manifold 2C are respectively provided via flow control valves 18 (opening / closing means). It is provided to be equipped. The flow control valves 8 are controlled by a control device (not shown) based on a signal from a sensor (not shown) provided in each cylinder 1, and the high-temperature air before the intercooler 16 is sent to each cylinder 1. It is like.

The control procedure of the sixth and seventh embodiments is the same as that of the flow chart of the fifth embodiment (FIG. 8). Opening and closing is performed.

FIGS. 11 to 13 show an embodiment in which part of exhaust gas is recirculated to intake air to cope with unstable combustion. In the eighth embodiment shown in FIG. 11, the exhaust gas recirculation path 21 branches off from the downstream of the exhaust manifold 3 in which the exhaust gas from each cylinder is integrated, and is further branched to each cylinder 1 to flow control valves respectively. The intake manifold 2C is opened to a branch path B to each cylinder via the intake manifold 22 via the intake manifold 22. Then, the combustion state is determined from a signal from a sensor (not shown) provided for each cylinder 1, and the flow control valve 22 is opened and closed by a control device (not shown) to control the recirculation amount of the exhaust gas.

The control procedure of the eighth embodiment will be described with reference to the flowchart of FIG. First, step S51
Then, the first cylinder is selected as the cylinder 1 to be controlled, and the combustion state is checked by the sensor 6 in step S52. Then, in step S53, it is determined whether the combustion state is stable, unstable, or knocking. If unstable, the flow control valve 22 is throttled in step S55 to reduce the exhaust circulation amount. Is maintained as it is (step S54).
The flow control valve 22 is opened to increase the exhaust circulation amount, and the process proceeds to step S57.

In step S57, it is checked whether the controlled (i) th cylinder is the last (Nth, in this example, 6th) cylinder. If not, the next (i + 1) th cylinder is checked in step S58. The cylinder is specified, and the process returns to step S52. If it is the last (No.) cylinder, it is determined in step S59 whether or not the control is completed.
Returning to No. 1, the process is repeated from the first cylinder 1a.

In the ninth embodiment shown in FIG. 13, the exhaust gas recirculation passages 21A are branched from the unified upstream of the exhaust manifold 3A, and are connected to the respective cylinders of the intake manifold 2C via the flow control valve 22. Are respectively opened to the branch paths B. The control procedure of the present embodiment is the same as that of FIG.

[0042]

The present invention is configured as described above, the combustion state is detected for each cylinder, the combustion is stabilized for each cylinder, and the variation of the self-ignition combustion between the cylinders is reduced. Leveling is achieved. Therefore, the startability and operation controllability of the entire engine are improved, and stable and highly efficient operation can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control procedure according to the first embodiment.

FIG. 3 is a flowchart illustrating a control procedure according to a second embodiment.

FIG. 4 is a flowchart illustrating a control procedure according to a third embodiment.

FIG. 5 is a diagram showing a configuration of a fourth embodiment.

FIG. 6 is a flowchart illustrating a control procedure according to a fourth embodiment.

FIG. 7 is a diagram showing a configuration of a fifth embodiment.

FIG. 8 is a flowchart illustrating a control procedure according to a fifth embodiment.

FIG. 9 is a diagram showing a configuration of a sixth embodiment.

FIG. 10 is a diagram showing a configuration of a seventh embodiment.

FIG. 11 is a diagram showing a configuration of an eighth embodiment.

FIG. 12 is a flowchart illustrating a control procedure according to an eighth embodiment.

FIG. 13 is a diagram showing a configuration of a ninth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2, 2A, 2B, 2C ... Intake manifold 3, 3A ... Exhaust manifold 5 ... Control device 6 ... Sensor 7 ... Fuel supply device 8 ... Intake amount adjustment Valve 11: Intake heater 12: Electric heater 12A: Heat exchanger 13: Flow control valve 14: Exhaust branch passage 15: Supercharger 16: Intercooler 17 ..Air supply branch passage 18 ... Flow regulating valve 21 ... Exhaust recirculation passage 22 ... Flow regulating valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 19/12 F02D 45/00 368D 45/00 368 368S 368Z F02M 25/07 570D F02M 25/07 570 570J 570P 570M 31/08 301B 31/08 301 31/12 311M 31/135 F02B 37/00 303B 31/12 311 F02M 31/12 301G F term (reference) 3G005 DA02 FA06 GB18 HA12 JA22 3G062 AA01 AA03 BA00 BA06 CA01 GA04 GA18 3G084 AA01 AA03 BA04 BA13 BA20 DA04 DA09 DA38 FA00 FA21 FA25 3G092 AA02 AB16 BA01 BB01 DC01 DC08 EA01 EA02 FA03 FA16 FA31 HC00Z HC01Z 3G301 HA02 HA06 HA13 JA00 JA03 JA22 LA00 LA01 MA11 NE01 NE06 PC00Z PC01Z PC08Z

Claims (11)

[Claims] In a control device for a homogeneous charge compression ignition engine having a plurality of cylinders, a sensor for detecting a combustion state is provided for each cylinder of the engine, and the control device includes a sensor for detecting a combustion state for each cylinder. The self-ignition property is determined based on the signal.If the self-ignition property is poor, the fuel supply amount is increased.If the knocking is present, the fuel supply amount is increased. A control device for a homogeneous charge compression ignition engine, wherein the control device is configured to perform decreasing control. 2. A control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine, and the control device uses the sensor for each cylinder. The self-ignition property is determined.If the self-ignition property is poor, the self-ignition accelerator is supplied.If the knocking is present, the self-ignition accelerator is determined. A control device for a homogeneous charge compression ignition engine, wherein the control device is configured to perform control for reducing supply. 3. A control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine, and the control device uses the sensor for each cylinder. Determine the ignitability,
In the case of premature ignition, a self-ignition inhibitor is supplied, and the stability of combustion is determined.If combustion is unstable, control is performed to reduce the supply of the self-ignition inhibitor. A control device for a homogeneous charge compression ignition engine, comprising: 4. A control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine, and an intake flow rate is adjusted in an intake path to each cylinder. Means for determining the combustion state by the sensor for each cylinder, and if it is determined that the combustion state is unstable, the control device reduces the intake air flow rate and determines that knocking has occurred. A control device for a premixed compression ignition engine, wherein the control device is configured to perform control to increase an intake air flow rate when the control is performed. 5. A control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine, and an intake heating means is provided in an intake path to each cylinder. The control device determines a combustion state by the sensor for each cylinder, and when it is determined that the combustion state is unstable, increases the intake air heating amount and determines that knocking has occurred. A control device for a premixed compression ignition engine, wherein the control device is configured to perform a control to reduce an intake heat amount in a case where the engine is heated. 6. The control device for a homogeneous charge compression ignition engine according to claim 5, wherein said intake air heating means is an electric heater. 7. The control device for a homogeneous charge compression ignition engine according to claim 5, wherein said intake air heating means is a heat exchanger between exhaust gas and intake air. 8. The intake air heating means includes a branch passage that supplies the high-temperature supercharged air immediately after passing through the supercharger to the intake passage by bypassing the intercooler, and an opening / closing unit that opens and closes the branch passage. 6. The control device for a homogeneous charge compression ignition engine according to claim 5, wherein said opening / closing means is configured to be opened / closed by said control device. 9. A control device for a homogeneous charge compression ignition engine having a plurality of cylinders, wherein a sensor for detecting a combustion state is provided for each cylinder of the engine, and an exhaust pipe is provided to an intake path to each cylinder. An exhaust gas recirculation path is connected with a control valve interposed therebetween, and the control device determines the combustion state by the sensor for each cylinder, and when it is determined that the combustion state is unstable, the exhaust gas recirculation amount The control device for a homogeneous charge compression ignition engine is characterized in that the control is performed such that when it is determined that knocking has occurred, the exhaust gas recirculation amount is increased. 10. The control device for a homogeneous charge compression ignition engine according to claim 1, wherein the sensor for detecting the combustion state is an in-cylinder pressure detection sensor. 11. The control device for a homogeneous charge compression ignition engine according to claim 1, wherein the sensor for detecting the combustion state is an ion probe.