Air-fuel ratio control system for internal combustion engine

U.S. Patent Number: 5343701

Abstract: An air-fuel ratio control system for an internal combustion engine utilizes a pre-stored standard relation between an air-fuel ratio sensor signal and a standard air-fuel ratio indicative value for deriving the standard air-fuel ratio indicative value based on the sensor signal. The system further utilizes a pre-stored modified relationship between the standard air-fuel ratio indicative value and a for-control air-fuel ratio indicative value for deriving a for-control air-fuel ratio indicative value based on the derived standard air-fuel ratio indicative value. In the modified relationship, the for-control air-fuel ratio indicative value varies with respect to a corresponding variation of the standard air-fuel ratio indicative value within a given range across the standard air-fuel ratio indicative value representing a stoichiometric air-fuel ratio.

Inventors: Douta; Hisayo (Kariya, JP), Kinugawa; Masumi (Okazaki, JP), Suzuki; Atsushi (Oobu, JP)

Assignee: Nippondenso Co., Ltd. (Kariya, JP)

Application Number: 07/949,689

Issued: 1994-09-06

Expired: 2006-09-06

Classes: 60/276 ; 123/680; 123/682

Field of search: 123/488,680,682,691,691,693,694 60/276,277,285

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