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US 8,297,266 B2Granted
Control apparatus for an internal combustion engine
AssigneeMitsubishi Electric Corporation
InventorHideki Takubo
Life of this patent
Estimating the term…
Abstract
Provided is a control apparatus for an internal combustion engine which is capable of estimating a single composition concentration based on an air-fuel ratio correction amount obtained by using an output of an air-fuel ratio sensor in exhaust gas and optimizing a fuel injection amount by using a concentration estimation value. When fueling is performed again during alcohol concentration change after the fueling, an alcohol concentration estimation period or a start determination period for the alcohol concentration change is extended by an integrated fuel injection amount from initial fueling until refueling, whereby alcohol concentration estimation accuracy is improved with respect to the alcohol concentration change due to the initial fueling and the refueling.
Claims11
A control apparatus for an internal combustion engine, comprising:
- a fuel supply device for supplying fuel in a fuel tank to the internal combustion engine;
- air-fuel ratio detecting means that is set in an exhaust system of the internal combustion engine, for detecting an air-fuel ratio in exhaust gas from the internal combustion engine;
- air-fuel ratio correction amount calculating means for calculating, based on a detection value of the air-fuel ratio detecting means, an air-fuel ratio correction amount for correcting a fuel injection amount to the internal combustion engine;
- concentration estimating means for calculating a concentration estimation value of a single composition of the fuel based on the air-fuel ratio correction amount calculated by the air-fuel ratio correction amount calculating means;
- and
- fuel injection amount calculating means for correcting the fuel injection amount based on the air-fuel ratio correction amount and the concentration estimation value,
- wherein the concentration estimating means comprises:
- fueling determining means for detecting that the fuel has been supplied to the fuel tank;
- concentration change period setting means for starting a concentration change period when it is determined by the fueling determining means that fueling has been performed and the fueling is in a period other than the concentration change period, and ending the concentration change period when an integrated fuel injection amount after start of the concentration change period reaches a first determination value;
- concentration change period extending means for increasing, when it is determined by the fueling determining means that the fueling has been performed and the fueling is in the concentration change period, the first determination value by an integrated fuel injection amount from a start time point of the concentration change period until a time point when it is determined that the fueling has been performed;
- and
- concentration update permitting means for permitting concentration update in the concentration change period;
- and
- the concentration estimating means extends a concentration estimation period when it is determined that refueling has been performed during concentration change.
11 more elements
A control apparatus for an internal combustion engine, comprising:
- a fuel supply device for supplying fuel in a fuel tank to the internal combustion engine;
- air-fuel ratio detecting means that is set in an exhaust system of the internal combustion engine, for detecting an air-fuel ratio in exhaust gas from the internal combustion engine;
- air-fuel ratio correction amount calculating means for calculating, based on a detection value of the air-fuel ratio detecting means, an air-fuel ratio correction amount for correcting a fuel injection amount to the internal combustion engine;
- concentration estimating means for calculating a concentration estimation value of a single composition of the fuel based on the air-fuel ratio correction amount calculated by the air-fuel ratio correction amount calculating means;
- and
- fuel injection amount calculating means for correcting the fuel injection amount based on the air-fuel ratio correction amount and the concentration estimation value,
- wherein the concentration estimating means comprises:
- fueling determining means for detecting that the fuel has been supplied to the fuel tank;
- start determining means for determining that a start condition is satisfied when the fueling is in the concentration change period and fluctuation in the air-fuel ratio correction amount increases;
- concentration change period setting means for starting a concentration change period when it is determined by the fueling determining means that fueling has been performed and the fueling is in a period other than the concentration change period, and ending the concentration change period when an integrated fuel injection amount after start of start determination reaches a second determination value;
- concentration change period extending means for increasing, when it is determined by the fueling determining means that the fueling has been performed and the fueling is in the concentration change period, the second determination value by an integrated fuel injection amount from a start time point of the concentration change period until a time point when it is determined that the fueling has been performed;
- and
- concentration update permitting means for permitting concentration update in a period from a time point of the start of the start determination until an end time point of the concentration change period;
- and
- the concentration estimating means extends a concentration estimation period after the start determination when it is determined that refueling has been performed during concentration change.
12 more elements
Dependencies are inferred from the claim text.