Exhaust gas purifying system for internal combustion engines

Patent · Tue Aug 12 04:00:00 EDT 1980

OSTI ID:6804905

Hattori, T; Kondo, K; Naito, J; Nakase, T

An exhaust gas purifying system of the type utilizing a threeway catalyst containing an oxygen storage material includes an electronic control unit for controlling the amount of secondary air supplied to the exhaust system of an internal combustion engine. The electronic control unit receives a signal from an exhaust air-fuel ratio sensor indicative of an air-fuel ratio of the exhaust gases and provides a pulse signal to an electromagnetic valve disposed in the passage of the secondary air leading to the upstream of the three-way catalyst. The amount of secondary air supplied to the exhaust system is controlled such that the resultant exhaust gases having an exhaust air-fuel ratio greater than the stoichiometric ratio and those having an exhaust air-fuel ratio smaller than the stoichiometric ratio are alternately supplied to the three-way catalyst thereby to achieve the average exhaust air-fuel ratio to fall within the optimum purifying conditions of the three-way catalyst.

• Assignee: Nippon Soken Inc (Japan)
• Patent Number(s): US 4216653
• OSTI ID: 6804905
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100 -- Internal Combustion Engines
330700* -- Advanced Propulsion Systems-- Emission Control
AIR
AIR POLLUTION CONTROL
CATALYSTS
CONTROL EQUIPMENT
DESIGN
ELECTRONIC CIRCUITS
ELEMENTS
ENGINES
EQUIPMENT
EXHAUST GASES
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NONMETALS
OXYGEN
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
PURIFICATION
WASTES