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:
Oct. 13, 1992
Filed:
Apr. 26, 1991
Nippondenso Co., Ltd., Kariya, JP;
Abstract
An air-fuel ratio control apparatus in which an air-fuel ratio of a mixture gas supplied to an engine, especially, a gas engine, is controlled in accordance with an output signal of each of oxygen concentration sensors disposed in upper and lower streams of an exhaust gas catalyzer of the engine. The output signal of the oxygen concentration sensor disposed on the upper stream side of the catalyzer is provided as one input signal of an air-fuel ratio control unit and the output signal of the oxygen concentration sensor disposed on the lower stream side of the catalyzer is provided as an input signal of an output signal correction amount determination unit, respectively. A mixing member for mixing an exhaust gas is disposed in an upper stream of each oxygen concentration sensor to detect the concentration of oxygen in the exhaust gas which is well mixed. The air-fuel ratio control unit controls an air-fuel ratio of a mixture gas in accordance with the output signal of the oxygen concentration sensor disposed on the upper stream side of the catalyzer and an output signal correction amount which is an output signal of the output signal correction amount determination unit. Since the exhaust gas is sufficiently mixed by the mixing member, variations of a measured value caused by the attachment position of each oxygen concentration sensor ar eliminated, thereby making it possible to control the air-fuel ratio of the mixture gas to a value close to a theoretical air-fuel ratio with a satisfactory precision.