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:
Mar. 01, 1983
Filed:
Dec. 30, 1980
Yoshiaki Ohara, Musashino, JP;
Makoto Shikata, Musashimurayama, JP;
Fuji Jukogyo Kabushiki Kaisha, Tokyo, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A system for controlling air-fuel ratio for an internal combustion engine having a two-barrel carburetor. An electronic controller compares the output signal of an O.sub.2 sensor with a reference corresponding to stoichiometry and for operating on-off electromagnetic valve(s) for controlling the air-fuel ratio to a value approximately equal to the stoichiometric air-fuel ratio. A constant signal generating circuit is selectively connected to the electronic controller. An engine operation detector is provided for detecting the transition from a heavy load condition to light load condition for producing a signal. A switching circuit operatively connects the constant signal generating circuit to the electronic controller for providing a fixed duty ratio of the valve, and renders the electronic controller non-responsive to the output of the O.sub.2 sensor. A switch actuating circuit is provided to actuate the switch by the output signal of the engine operation detector for a predetermined period. Thus, the on-off electromagnetic valve is operated at a small duty ratio after the heavy load condition for a predetermined period.