AIR-FUEL MIXTURE CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

• Main Author: SHITAMACHI TAKASHI
• Format: Patent
• Language: English
• Published: 29.11.2007
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To quickly bring oxygen storage amounts of an upstream side catalyst and a downstream side catalyst to appropriate amounts after fuel cut recovery. SOLUTION: This air-fuel mixture control device is applied to an internal combustion engine including the upstream side catalyst 53 and the downstream side catalyst 54 disposed in series in an exhaust passage. The control device matches the air-fuel ratio of the air-fuel mixture supplied to the engine to the theoretical air-fuel ratio when the operation condition of the engine satisfies a normal operation condition. The control device performs fuel cut operation when the operation condition of the engine satisfies a fuel cut operation condition. Further, the control device controls the flow rate (air amount) of the air-fuel mixture and the air-fuel ratio of the air-fuel mixture so that unburned gas of a larger flow rate than a maximum purification flow rate of unburned gas which is the maximum flow rate of unburned gas that can be purified by the upstream side catalyst 53 flows into the upstream side catalyst 53 from the point where fuel cut operation is completed and fuel supply is restarted to the point where a predetermined period has passed. COPYRIGHT: (C)2008,JPO&INPIT