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:
Apr. 20, 1993
Filed:
Nov. 05, 1991
Mitsuo Hitomi, Hiroshima, JP;
Toshihiko Hattori, Hiroshima, JP;
Kenji Kashiyama, Hiroshima, JP;
Junsou Sasaki, Hiroshima, JP;
Kazuaki Umezawa, Hiroshima, JP;
Tadayoshi Kaide, Hiroshima, JP;
Noriyuki Iwata, Hiroshima, JP;
Naoyuki Yamagata, Hiroshima, JP;
Kazumasa Nomura, Hiroshima, JP;
Mazda Motor Corporation, Hiroshima, JP;
Abstract
Disclosed is an exhaust gas recirculation system for an engine having a high compression ratio or with a supercharger. An outside EGR duct connecting the exhaust system to the intake system is provided with a first control valve, which has a second outside EGR duct bypassing the first control valve. The second EGR duct has a second EGR control valve and a cooler. When the engine exists in an extremely low load state, the first and second control valves are closed to inhibit the outside EGR. In the light load state, the first control valve is opened while the second control valve is closed, thereby allowing recirculation of the EGR gases having high temperature and reducing the pumping loss. In the high load state, the first control valve is being closed while opening the second control valve, thereby increasing a recirculation ratio of EGR gases cooled by the cooler and performing both an improvement of anti-knocking performance and a decrease in pumping loss, as well as reducing the heat load of the exhaust system and within the engine.