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:
Aug. 21, 1979
Filed:
Mar. 31, 1977
Tadashi Hattori, Okazaki, JP;
Akira Takata, Toyota, JP;
Tamotsu Fukuda, Toyota, JP;
Takamichi Nakase, Gamagori, JP;
Nippon Soken, Inc., Nishio, JP;
Toyota Jidosha Kogyo Kabushiki Kaisha, Toyota, JP;
Abstract
An apparatus for controlling the air-fuel ratio of an air-fuel mixture to be supplied into a combustion chamber of an internal combustion engine comprises a passage bypassing a carburetor and a throttle valve of the engine for supplying an additional air into the engine intake duct downstream of the throttle valve to dilute the air-fuel mixture to an air-fuel ratio most suited for the engine operation. An air valve is provided in the bypass passage to vary the air-flow cross-sectional area of the passage. The opening of the air valve is controlled mainly in accordance with the air-fuel ratio of the mixture as detected by an air-fuel ratio detector in the path of flow of engine exhaust gases. A variable orifice is provided in the bypass passage downstream of the air valve and defined by a valve seat and a needle valve operatively associated therewith to vary the opening area of the orifice. The needle valve is actuated by a pneumatic valve actuator which is responsive to variations in the engine manifold vacuum. The arrangement is such that the pressure difference across the air valve is kept substantially constant whereby the supply of the additional air is substantially in proportion to the engine intake air and free from influence by the engine manifold vacuum.