System for feedback control of air/fuel ratio in internal combustion engine

Patent · Tue Jul 06 04:00:00 EDT 1982

OSTI ID:6543563

Masaki, K

A system for feedback control of air/fuel ratio in an internal combustion engine operated with a nonstoichiometric air-fuel mixture. The control system includes two oxygen-sensitive air/fuel ratio sensors which are of the concentration cell type having a solid electrolyte layer provided with two electrode layers and both disposed in an exhaust passage substantially at the same section. The first sensor is supplied with a constant dc current to cause migration of oxygen ions through the solid electrolyte layer and exhibits a slope output characteristic when a lean mixture or a rich mixture is supplied to the engine, depending on the direction of flow of the current. The second sensor exhibits on-off type output characteristic and can discriminate between a lean mixture and a rich mixture. A control circuit to produce a fuel feed rate control signal based on the output of the first sensor includes a discriminating means for ascertaining whether the output of the first sensor is truly attributed to the slope output characteristic with reference to the output of the second sensor.

• Assignee: Nissan Motor Co Ltd (Japan)
• Patent Number(s): US 4337746
• OSTI ID: 6543563
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
DC SYSTEMS
DIESEL ENGINES
ELECTRICAL EQUIPMENT
ELECTROLYTES
ENERGY SYSTEMS
ENGINES
EQUIPMENT
EXHAUST GASES
FEEDBACK
FLUIDS
FUEL SYSTEMS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
POROSITY
POWER SYSTEMS
SIGNALS
SOLID ELECTROLYTES
SUBSTRATES
SWITCHES
WASTES