Air-fuel ratio control apparatus

Patent · Tue Apr 08 04:00:00 EST 1986

OSTI ID:5856739

Kitahara, T

This patent describes an air-fuel ratio control apparatus for controlling an air-fuel ratio of a fuel mixture supplied to an internal combustion engine which effects combustion of the fuel mixture to produce exhaust gases. The apparatus consists of: means for detecting the air-fuel ratio of the fuel mixture over a range from a rich range portion thereof to a lean range portion means for detecting a warming-up operation of the internal combustion engine and generating a warming-up operation indicative signal; means for determining a first and second target value indicative of an air-fuel value optimal for warming-up and normal operationin response to the presence or lack of the indicative signal; means for comparing the actual air-fuel ratio indicative signal with the target value indicative signal means for controlling the air-fuel ratio. The air-fuel ratio detecting means consists of: A partition having a first side and a second side opposite to the first side. The partition defining on the first side an atmospheric air receiving portion communicating with the ambient atmosphere and on the second side a gas receiving portion communicating with a source of the exhaust gases; the partition has at least a portion formed of an oxygen ion-conductive solid electrolyte; first electrode means exposed to the atmospheric air receiving portion; second electrode means to the exhaust gases; means for restricting gas diffusion of the exhaust gases to the gas receiving portion; current providing means for providing an electric current to flow between the first and second electrode means through the electrolyte in such a manner as to cause migration of oxygen ions through the electrolyte between the atmospheric air receiving portion and the gas receiving portion so as to keep an oxygen partial pressure ratio across the electrolyte constant; and means for detecting the electric current.

• Assignee: Nissan Motor Co., Ltd., Yokohama
• Patent Number(s): US 4580539
• OSTI ID: 5856739
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
AIR FLOW
CHEMICAL REACTIONS
COMBUSTION
CONTROL SYSTEMS
CURRENTS
DISPERSIONS
ELECTRIC CURRENTS
ELECTRODES
ELECTROLYTES
ENGINES
EXHAUST GASES
FLUID FLOW
FLUIDS
FUEL-AIR RATIO
GAS FLOW
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERS
MIXTURES
OXIDATION
OXYGEN METERS
PARTIAL PRESSURE
SIGNALS
SOLID ELECTROLYTES
START-UP
THERMOCHEMICAL PROCESSES
WASTES