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. 21, 1978
Filed:
Oct. 12, 1973
Hisanori Moriya, Katsuta, JA;
Tadao Osawa, Katsuta, JA;
Hitachi, Ltd., Tokyo, JA;
Abstract
An exhaust gas recirculation system whereby a part of exhaust gas is recirculated to the downstream of the carburetor throttle valve through an exhaust recirculation passage for removing the nitrogen oxides in exhaust gas discharged from an internal combustion engine, wherein a pressure control valve is provided in the after-flow of the flow control valve which controls the rate of exhaust gas recirculated to the downstream of the throttle valve disposed halfway in said exhaust recirculation passage, said pressure control valve being arranged such that its opening will be reduced when negative pressure in the downstream of the throttle valve is high and that said opening will be enlarged when said negative pressure is low, whereby the amount of exhaust gas taken into the engine is made basically proportional to the air intake so that the recirculation ratio will be maintained substantially constant over a wide range of operation.