Control system and method for in-cylinder injection internal combustion engine

Claim 2

A control system for an in-cylinder injection internal combustion engine capable of selecting an intake stroke injection mode, in which an injection of fuel is performed primarily in an intake stroke, or a compression stroke injection mode, in which an injection of fuel is performed primarily in a compression stroke, as a fuel injection mode in accordance with a state of operation, comprising: a fuel injection valve for directly injecting fuel into a combustion chamber of said internal combustion engine; a spark plug arranged in said combustion chamber to ignite an air-fuel mixture in said combustion chamber; an exhaust gas recirculation system for recirculating a portion of exhaust gas of said internal combustion engine to an intake system of said internal combustion engine; burning fluctuation detecting unit for detecting a fluctuated state of burning in said internal combustion engine; fuel injection timing control unit for controlling a fuel injection timing of said fuel injection valve on a basis of a target fuel injection timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; ignition timing control unit for controlling an ignition timing of said spark plug on a basis of a target ignition timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; and exhaust gas recirculation rate control unit for controlling an exhaust gas recirculation rate of said exhaust gas recirculation system on a basis of a target exhaust gas recirculation rate preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; whereby during said compression stroke injection mode, said control system corrects at least one of said fuel injection timing, said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 3

The control system according to claim 1, wherein said control system corrects at least said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 4

The control system according to claim 1, wherein said control system corrects at least said fuel injection timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 5

The control system according to claim 1, wherein said control system corrects at least said fuel injection timing and said ignition timing in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 6

The control system according to claim 1, wherein said control system corrects said fuel injection timing, said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 7

The control system according to claim 1, wherein upon detection of a burning fluctuation by said burning fluctuation detecting unit, said control system retards said fuel injection timing by a first predetermined angle so that burning fluctuations are reduced.

Claim 8

The control system according to claim 1, wherein upon detection of a burning fluctuation by said burning fluctuation detecting unit, said control system retards said ignition timing by a second predetermined angle so that burning fluctuations are reduced.

Claim 9

The control system according to claim 1, wherein upon detection of a burning fluctuation by said burning fluctuation detecting unit, said control system decreases said exhaust gas recirculation rate by a predetermined amount so that burning fluctuations are reduced.

Claim 10

The control system according to claim 1, wherein, when burning fluctuations are not reduced despite said correction, said control system switches said fuel injection mode from said compression stroke injection mode to said intake stroke injection mode.

Claim 11

The control system according to claim 1, wherein said control system further comprises air/fuel ratio control unit for controlling operation of said fuel injection valve on a basis of a preset target air/fuel ratio; and during said intake stroke injection mode, said air/fuel ratio control unit corrects said target air/fuel ratio in accordance with results of a detection by said burning fluctuation detecting unit.

Claim 12

The control system according to claim 1, wherein said target fuel injection timing and said target ignition timing are set at or in a vicinity of timings where a best gas mileage of said internal combustion engine is available.

Claim 13

The control system according to claim 4, wherein a correction value of said fuel injection timing and a correction value of said ignition timing are set at substantially the same angle.

Claim 14

The control system according to claim 6, wherein said first predetermined angle is set corresponding to a state of operation of said internal combustion engine.

Claim 15

The control system according to claim 7, wherein said second predetermined angle is set corresponding to a state of operation of said internal combustion engine.

Claim 16

The control system according to claim 8, wherein said predetermined amount upon decreasing said exhaust gas recirculation rate is set corresponding to a state of operation of said internal combustion engine.

Claim 17

The control system according to claim 4, wherein said internal combustion engine is provided with plural cylinders; and said control system performs said corrections of said fuel ignition timing and said ignition timing with respect to each of said cylinders.

Claim 18

The control system according to claim 1, wherein said burning fluctuation detecting unit detects occurrence of a misfire in said combustion chamber.

Claim 19

A control method for an in-cylinder injection internal combustion engine capable of selecting an intake stroke injection mode, in which an injection of fuel is performed primarily in an intake stroke, or a compression stroke injection mode, in which an injection of fuel is performed primarily in a compression stroke, as a fuel injection mode in accordance with a state of operation, comprising a fuel injection valve for directly injecting fuel into a combustion chamber of said internal combustion engine, a spark plug arranged in said combustion chamber to ignite an air-fuel mixture in said combustion chamber, an exhaust gas recirculation system for recirculating a portion of exhaust gas of said internal combustion engine to an intake system of said internal combustion engine; burning fluctuation detecting unit for detecting a fluctuated state of burning in said internal combustion engine, fuel injection timing control unit for controlling a fuel injection timing of said fuel injection valve, ignition timing control unit for controlling an ignition timing of said spark plug, and exhaust gas recirculation rate control unit for controlling an exhaust gas recirculation rate of said exhaust gas recirculation system, said control method comprising the following steps: controlling a fuel injection timing of said fuel injection valve on a basis of a target fuel injection timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; controlling an ignition timing of said spark plug on a basis of a target ignition timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; controlling an exhaust gas recirculation rate of said exhaust gas recirculation system on a basis of a target exhaust gas recirculation rate preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; and correcting at least one of said fuel injection timing, said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit during said compression stroke injection mode.

Claim 20

A control method for an in-cylinder injection internal combustion engine capable of selecting an intake stroke injection mode, in which an injection of fuel is performed primarily in an intake stroke, or a compression stroke injection mode, in which an injection of fuel is performed primarily in a compression stroke, as a fuel injection mode in accordance with a state of operation, comprising a fuel injection valve for directly injecting fuel into a combustion chamber of said internal combustion engine, a spark plug arranged in said combustion chamber to ignite an air-fuel mixture in said combustion chamber, an exhaust gas recirculation system for recirculating a portion of exhaust gas of said internal combustion engine to an intake system of said internal combustion engine; burning fluctuation detecting unit for detecting a fluctuated state of burning in said internal combustion engine, fuel injection timing control unit for controlling a fuel injection timing of said fuel injection valve, ignition timing control unit for controlling an ignition timing of said spark plug, and exhaust gas recirculation rate control unit for controlling an exhaust gas recirculation rate of said exhaust gas recirculation system, said control method comprising the following steps: controlling a fuel injection timing of said fuel injection valve on a basis of a target fuel injection timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; controlling an ignition timing of said spark plug on a basis of a target ignition timing preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; controlling an exhaust gas recirculation rate of said exhaust gas recirculation system on a basis of a target exhaust gas recirculation rate preset corresponding to a state of operation of said internal combustion engine during normal operation of said internal combustion engine; and correcting at least one of said fuel injection timing, said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit during said compression stroke injection mode.

Claim 21

The control method according to claim 18, wherein said burning fluctuations reducing step comprises correcting at least said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 22

The control method according to claim 18, wherein said burning fluctuations reducing step comprises correcting at least said fuel injection timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 23

The control method according to claim 18, wherein said burning fluctuations reducing step comprises correcting at least said fuel injection timing and said ignition timing in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 24

The control method according to claim 18, wherein said burning fluctuations reducing step comprises correcting said fuel injection timing, said ignition timing and said exhaust gas recirculation rate in accordance with results of a detection by said burning fluctuation detecting unit so that burning fluctuations are reduced.

Claim 25

The control method according to claim 18, wherein said burning fluctuations reducing step comprises retarding said fuel injection timing by a first predetermined angle so that burning fluctuations are reduced.

Claim 26

The control method according to claim 18, wherein said burning fluctuations reducing step comprises retarding said ignition timing by a second predetermined angle so that burning fluctuations are reduced.

Claim 27

The control method according to claim 18, wherein said burning fluctuations reducing step comprises decreasing said exhaust gas recirculation rate by a predetermined amount so that burning fluctuations are reduced.

Claim 28

The control method according to claim 18, wherein said control method further comprises a step in which, when said burning fluctuations are not reduced despite the performance of said burning fluctuations reducing step, said fuel injection mode is switched from said compression stroke injection mode to said intake stroke injection mode.

Claim 29

The control method according to claim 18, wherein said internal combustion engine further comprises air/fuel ratio control unit for controlling operation of said fuel injection valve on a basis of a preset target air/fuel ratio; and during said intake stroke injection mode, said burning fluctuations reducing step corrects said target air/fuel ratio in accordance with results of a detection by said burning fluctuation detecting unit.

Claim 30

The control method according to claim 18, wherein said target fuel injection timing and said target ignition timing are set at or in a vicinity of timings where a best gas mileage of said internal combustion engine is available.

Claim 31

The control method according to claim 21, wherein a correction value of said fuel injection timing and a correction value of said ignition timing are set at substantially the same angle.

Claim 32

The control method according to claim 23, wherein said first predetermined angle is set corresponding to a state of operation of said internal combustion engine.

Claim 33

The control method according to claim 24, wherein said second predetermined angle is set corresponding to a state of operation of said internal combustion engine.

Claim 34

The control method according to claim 25, wherein said predetermined amount upon decreasing said exhaust gas recirculation rate is set corresponding to a state of operation of said internal combustion engine.

Claim 35

The control method according to claim 21, wherein said internal combustion engine is provided with plural cylinders; and said burning fluctuations reducing step comprises performing said corrections of said fuel ignition timing and said ignition timing with respect to each of said cylinders.

Claim 36

The control method according to claim 18, wherein said burning fluctuation detecting unit detects occurrence of a misfire in said combustion chamber.