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

Exhaust gas purifying method of an internal combustion engine

Patent ·
OSTI ID:6189249
An air-fuel ratio discrimination signal, having two voltage levels depending upon whether the air-fuel ratio of the engine is rich or lean in comparison with a predetermined air-fuel ratio, is generated in accordance with the sensed signal from a sensor which detects the concentration of a particular component in the exhaust gas. Then, the amount of secondary air supplied into the exhaust system of the engine is gradually increased or decreased in accordance with the level of the air-fuel ratio discrimination signal. Furthermore, the amount of secondary air supplied into the exhaust system is additionally increased or decreased in accordance with the average value of the air-fuel ratio discrimination signal.
Assignee:
Toyota Jidosha Kogyo K K (Japan)
Patent Number(s):
US 4375746
OSTI ID:
6189249
Country of Publication:
United States
Language:
English