Combustion control system for diesel engine
AssigneeNissan Motor Co., Ltd.
InventorShuji Kimura
Life of this patent
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Abstract
A combustion control system for a diesel engine provided with a fuel injection system and a sensor for detecting an ignition timing. The combustion control system comprises a control unit which is configured to control the ignition timing to be restored to a target value when the ignition timing shifts from the target value owing to circumferential factors such as cetane number of fuel. Preferably, the ignition timing is controlled to generally coincide with or be retarded relative to a fuel injection termination timing. This regulates an ignition delay period to be longer than a fuel injection period in a predetermined engine operating region, thereby effectively accomplishing so-called low temperature premix combustion.
Claims13
A combustion control system for a diesel engine, comprising:
- a section for changing an ignition delay period defined as a time period between the instant when fuel injection is started and the instant when fuel starts burning;
- a section for changing a fuel injection rate defined as a quantity of fuel per unit of time;
- a section for detecting an ignition at which fuel starts burning;
- a section for controlling at least one of the section for changing the ignition delay period and the section for changing the fuel injection rate based on the detected ignition timing in a predetermined engine operation region to complete the fuel injection within the ignition delay period;
- and
- an engine EGR rate sensor to sense an EGR rate, wherein, when the sensed EGR rate increases, the timing of the fuel injection start is retarded toward top dead center of a compression stroke.
A combustion control system for a diesel engine, comprising:
- a section for detecting an ignition timing at which fuel starts burning;
- a section for controlling the detected ignition timing to generally coincide with or be retarded relative to a fuel injection termination timing based on the detected ignition timing in a predetermined engine operating region;
- and
- an engine EGR rate sensor to sense an EGR rate, wherein, when the sensed EGR rate increases, the timing of the fuel injection start is retarded toward top dead center of a compression stroke.
A combustion control system for a diesel engine, comprising:
- a section for detecting ignition timing at which fuel starts burning;
- a section for judging that the detected ignition timing is retarded relative to a target value;
- a section for controlling the ignition timing so as to be restored to the target value when the detected ignition timing is retarded relative to the target value;
- and
- an engine EGR rate sensor to sense an EGR rate, wherein, when the sensed EGR rate increases, the timing of the fuel injection start is retarded toward top dead center of a compression stroke.
Dependencies are inferred from the claim text.