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

Exhaust gas recirculation apparatus for an internal combustion engine

Patent ·
OSTI ID:6697637

An exhaust gas recirculation apparatus for an internal combustion engine is described that is provided with a vacuum-operated EGR valve having a diaphragm which forms a vacuum control chamber on one side of the diaphragm, which chamber is connected to a vacuum port formed in the engine intake system for transmitting a vacuum signal to the chamber in order to operate the EGR valve for controlling the amount of exhaust gas to be recirculated. The apparatus is further provided with a temperature detecting valve adapted for introducing a limited amount of air through an orifice when the engine is operating under a warm-up condition during which the temperature of the engine is not yet sufficiently increased, so that the amount of the gas recirculated during such an operation is decreased to some extent. The amount of the emission of NO/sub x/ component is slightly increased whereas the amounts of the emissions of CO and HC components are decreased. Therefore, the amount of the emissions of the three major toxic components NO/sub x/, CO and HC are equalized.

Assignee:
Toyota Jidosha Kogyo Kabushiki Kaisha
Patent Number(s):
US 4090482
OSTI ID:
6697637
Country of Publication:
United States
Language:
English