Exhaust gas purification system for an internal combustion engine

Patent · Tue Jun 02 04:00:00 EDT 1981

OSTI ID:6127328

Fukuba, A; Morishita, M; Nishi, T; Ouchi, H; Tanaka, K

An engine exhaust gas purification system has a secondary air system for supplying secondary air into the engine exhaust system. The secondary air system has an air metering valve and a switching valve. The air metering valve is operative to meter the secondary air supply in accordance with signals emitted by an air -fuel ratio sensor disposed in the exhaust system to detect the oxygen content of engine exhaust gases. The switching valve is disposed in the secondary air supply line downstream of the air metering valve to interrupt the supply of the secondary air into the exhaust system during a high load engine operation for thereby preventing the exhaust system and, particularly, the catalyst device therein from being overheated. The force to close the switching valve is strong enough to keep the valve closed against the counter-flow of engine exhaust gases from engine exhaust system back into the secondary air system.

• Assignee: Nippondenso Co Ltd (Japan); Toyota Jidosha Kogyo K K (Japan)
• Patent Number(s): US 4270347
• OSTI ID: 6127328
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100 -- Internal Combustion Engines
330700* -- Advanced Propulsion Systems-- Emission Control
AIR FLOW
CATALYSTS
CONTROL EQUIPMENT
ENGINES
EQUIPMENT
EXHAUST GASES
FLOW REGULATORS
FLUID FLOW
FLUIDS
FUEL-AIR RATIO
GAS FLOW
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERS
OXYGEN METERS
POLLUTION CONTROL EQUIPMENT
PURIFICATION
VALVES
WASTES