The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1998
Filed:
Dec. 24, 1996
Masahiko Teraoka, Aichi-ken, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
Disclosed is an air-fuel ratio control apparatus, which controls the air-fuel ratio of a flammable air-fuel mixture to be supplied to an engine. This control apparatus controls the air-fuel ratio taking into account that fuel vapor produced in a fuel tank is added to the air-fuel mixture. The fuel vapor produced in the fuel tank is purged into the intake passage of the engine through a canister. An electronic control unit (ECU) controls the amount of fuel to be injected from each injector such that the air-fuel ratio of the air-fuel mixture matches a target air-fuel ratio. At the time the fuel vapor is purged, the ECU learns the density of fuel to be purged based on the detected value of an oxygen sensor. Based on this learned value, the ECU compensates the amount of fuel to be injected from each injector. When no fuel vapor flows to the canister from the fuel tank, the ECU specifies the learned value as being associated with the fuel vapor separated from the canister to be indirectly purged and compensates that learned value accordingly. When fuel vapor flows to the canister from the fuel tank, the ECU specifies the learned value as being associated with the fuel vapor that simply passes the canister to be directly purged and compensates that learned value accordingly.