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:
Jan. 16, 2001
Filed:
Jun. 01, 1999
Norio Matsumoto, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An air-fuel ratio control apparatus for an internal combustion engine calculates a purge rate from a purge amount and an engine operating state, calculates a purge air density from the purge rate and an air-fuel ratio correcting coefficient, and calculates a purge air density correcting coefficient based on the purge rate and the purge air density. Further, the air-fuel ratio control apparatus calculates a learned air-fuel ratio feedback correction value from the air-fuel ratio feedback correcting coefficient, calculates a fuel injection amount based on the air-fuel ratio feedback correcting coefficient, the learned air-fuel ratio feedback correction value and the purge air density correcting coefficient, and alternately switches over the learning of the air-fuel ratio feedback correction and the learning of the purge air density. With this arrangement, when purge control is carried out, the air-fuel ratio control apparatus can control the air-fuel ratio of a mixture to be introduced into the internal combustion engine to a target value with excellent accuracy at all times.