Apparatus and a method for controlling a diesel engine
AssigneeNissan Motor Co., Ltd.
InventorShuji Kimura
Life of this patent
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Abstract
In a diesel engine, heavy EGR lowers a combustion temperature, which greatly prolongs an ignition delay period and all fuel is injected within the ignition delay period, thereby performing a low-temperature premixed combustion. A crank angle from a fuel injection completion to an ignition start is made less than 15 degrees by advancing a fuel injection timing and/or prolonging a fuel injection period. As a result, an equivalent ratio distribution in a combustion chamber at an ignition start is controlled such that an equivalent ratio in the vicinity of a cylinder center is richer than in the vicinity of a cylinder wall and the equivalent ratio gradually changes from the cylinder center to the cylinder wall.
Claims12
An apparatus for controlling a diesel engine comprising:
- a temperature lowering device which lowers a combustion temperature in a combustion chamber;
- and
- a fuel injection control apparatus which controls a fuel injection to prolong an ignition delay period under operation of the temperature lowering device in a manner that a heat release pattern in the combustion chamber becomes a one-step combustion state,
- wherein, at an ignition start, an equivalence ratio distribution in the combustion chamber is corrected by the fuel injection control apparatus in a manner that an equivalent ratio is richer in the vicinity of a cylinder center than in the vicinity of a cylinder wall and gradually changes from the cylinder center to the cylinder wall.
A method for controlling a diesel engine comprising:
- lowering a combustion temperature in a combustion chamber, and
- controlling a fuel injection to prolong an ignition delay period in a manner that a heat release pattern becomes a one-step combustion state and to control an equivalent ratio distribution in a combustion chamber at an ignition start in a manner that an equivalent ratio is richer in the vicinity of a cylinder center than in the vicinity of a cylinder wall and gradually changes from the cylinder center to the cylinder wall.
Dependencies are inferred from the claim text.