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US 5,595,060 AGranted
Apparatus and method for internal-combustion engine control
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsKazuhide Togai, Kazuo Koga
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AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsKazuhide Togai, Kazuo Koga
Estimating the term…
In a control apparatus and control method for an internal combustion engine having an exhaust purifying catalytic device for adsorbing nitrogen oxide contained in exhaust gases from the engine, the adsorption state of nitrogen oxide adsorbed by the catalytic device is estimated by an electronic control unit during the lean-combustion driving of the engine. If the catalytic device is saturated with nitrogen oxide, the ignition timing is delayed and the exhaust gas is recirculated to the intake side of the engine with the lean air-fuel ratio kept unchanged. This starts the nitrogen oxide reduced driving mode for deteriorating the combustion state in the engine. At this time, the engine output will not change by a great amount. Further, a reducing atmosphere is created around the catalytic device by unburnt gases, generated due to the deterioration of the combustion state, to deoxidize the adsorbed nitrogen oxide. As a result, the purifying ability of the catalytic device can be recovered to suppress the discharge amount of nitrogen oxide without deteriorating the smoothness of engine driving and fuel economy.
A control apparatus for an internal combustion engine having an exhaust purifying catalytic device disposed in an exhaust passage for reducing emission of nitrogen oxide to atmosphere, the exhaust purifying catalytic device being operable to adsorb nitrogen oxide contained in exhaust gases discharged from the internal combustion engine when the engine is in a lean-combustion mode where an air-fuel ratio of an air-fuel mixture supplied to the engine is leaner than a theoretical air-fuel ratio, and to deoxidize adsorbed nitrogen oxide when the internal combustion engine is in a rich-combustion mode where the air-fuel ratio is equal to or richer than the theoretical air-fuel ratio, comprising:
A control apparatus for an internal combustion engine having an exhaust purifying catalytic device disposed in an exhaust passage for reducing emission of nitrogen oxide discharged to atmosphere, the exhaust purifying catalytic device being operable to adsorb nitrogen oxide, contained in exhaust gases discharged from the internal combustion engine when the internal combustion engine is in a lean-combustion mode where an air-fuel ratio of an air-fuel mixture supplied to the engine is leaner than a theoretical air-fuel ratio, and to deoxidize adsorbed nitrogen oxide when the engine is in a rich-combustion mode where the air-fuel ratio is equal to or richer than the theoretical air-fuel ratio, comprising:
An internal combustion engine control method for reducing emission of nitrogen oxide to atmosphere, by causing nitrogen oxide, contained in exhaust gases discharged from an internal combustion engine, to be absorbed by an exhaust purifying catalytic device, disposed in an exhaust passage of the internal combustion engine, when the engine is in a lean-combustion mode where an air-fuel ratio of an air-fuel mixture supplied to the engine is leaner than a theoretical air-fuel ratio, and by deoxidizing adsorbed nitrogen oxide by means of the exhaust purifying catalytic device when the internal combustion engine is in a rich-combustion mode where the air-fuel ratio is equal to or richer than the theoretical air-fuel ratio, comprising:
An internal combustion engine control method for reducing emission of nitrogen oxide to atmosphere, by causing nitrogen oxide, contained in exhaust gases discharged from the internal combustion engine, to be absorbed by an exhaust purifying catalytic device disposed in an exhaust passage of the internal combustion engine when the engine is in a lean-combustion mode where an air-fuel ratio of an air-fuel mixture supplied to the internal combustion engine is leaner than a theoretical air-fuel ratio, and by deoxidizing adsorbed nitrogen oxide by means of the exhaust purifying catalytic device when the engine is in a rich-combustion mode where the air-fuel ratio is equal to or richer than the theoretical air-fuel ratio, comprising:
Dependencies are inferred from the claim text.