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:
Sep. 25, 1979
Filed:
Dec. 23, 1977
Syunichi Aoyama, Yokohama, JP;
Nissan Motor Company, Limited, Yokohama, JP;
Abstract
An EGR (Exhaust Gas Recirculation) control system comprises EGR control valve means including a first fluid chamber the vacuum in which increases and decreases in accordance with operating conditions of the engine whereby EGR control valve means control the recirculated amount of exhaust gases back to the engine and a second fluid chamber receiving therein a suction vacuum to thereby cause multiplication of the vacuum in the first chamber without altering the correspondency between the operating condition of the engine and the degree of opening of the EGR control valve means whereby the variable range of the vacuum in the first fluid chamber is optimally enlarged. An EGR control system further comprises relief valve means for reducing the EGR ratio below a predetermined constant level upon high speed low load operating condition of the engine and which includes a fluid chamber directly communicating with the first fluid chamber of the EGR control valve means whereby the relief valve means is operated by the vacuum substantially equal to the vacuum in the first fluid chamber of the EGR control valve means.