| 摘要 |
PROBLEM TO BE SOLVED: To suppress worsening of a fuel consumption rate by stabilizing a combustion state at the time of ensuring negative pressure in an internal combustion engine provided with a brake booster and capable of performing stratified combustion. SOLUTION: All electronic control unit(ECU) 30 executes totally closing control of a throttle valve 23 in the case of needing to ensure negative pressure for the operation of a brake booster 71 ensuring the braking force of a vehicle. The ECU 30 executes stratified combustion in case of the target injection quantity being the injection quantity for changeover judgment or less and changes over to uniform combustion in the case of becoming larger than the injection quantity for changeover judgment. The ECU 30 sets the injection quantity for chageover judgment to the small value in case of negative pressure ensuring control being executed in a state of stratified combustion being in progress. In case of the negative pressure ensuring control being executed, an overrich reaching limit becomes early in association with the increase of load, but since the injection quantity for changeover judgment is changed to the small value in conformity to this, the changeover to uniform combustion is made early. |
