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U.S. Department of Energy
Office of Scientific and Technical Information

Exhaust-gas recirculation system

Patent ·
OSTI ID:5485848

An exhaust-gas recirculation (EGR) system for an internal-combustion engine comprises an EGR valve for controlling the amount of exhaust-gas recirculation installed midway in an EGR passage that establishes communication between the intake and exhaust pipes of the engine, and an exhaust-gas transducer valve for opening and closing by the exhaust pressure of the exhaust gas an atmospheric-releasing orifice formed midway in a vacuum conduit for introducing vacuum into the EGR valve. An acceleration control unit is connected to the exhaust-pressure transducer valve to prevent the entry of air from the atmospheric-releasing orifice into the vacuum conduit in the early stage of engine acceleration, even while the transducer valve is in operation, so as to control the generation of nitrous oxides during the acceleration.

Assignee:
Hitachi, Ltd.
Patent Number(s):
US 4173955
OSTI ID:
5485848
Country of Publication:
United States
Language:
English