System for feedback control of air/fuel ratio in ic engine having means for supplying controlled current to oxygen sensor

Patent · Mon Dec 13 23:00:00 EST 1982

OSTI ID:6528658

Nakagawa, T; Okamura, K; Sone, K

A system for feedback control of air/fuel ratio in an internal combustion engine, utilizing an oxygen-sensitive air/fuel ratio detector disposed in an exhaust gas to provide a feedback signal is disclosed. The detector has a flat and microscopically porous solid electrolyte layer with a measurement electrode layer on one side and a reference electrode layer on the other side facing a substrate. The control system includes a current supplying circuit to force a dc current to flow in the solid electrolyte layer between the two electrode layers to cause migration of oxygen ions through the solid electrolyte layer from the measurement electrode toward the reference electrode to thereby establish a reference oxygen partial pressure at the interface between the reference electrode layer and the solid electrolyte layer. To preclude an undesirably great rise of this reference oxygen partial pressure in the case of a large increase in the amount of oxygen in the exhaust gas resulting from interruption, or great reduction, of the feed of fuel to the operating engine, the control system comprises sensor means to detect the existence of such a condition and means for temporarily decreasing the intensity of the current being supplied to the air/fuel ratio detector.

• Assignee: Nissan Motor Co Ltd (Japan)
• Patent Number(s): US 4363306
• OSTI ID: 6528658
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
CURRENTS
DETECTION
DIRECT CURRENT
ELECTRIC CURRENTS
ELECTROLYTES
ELEMENTS
ENGINES
EXHAUST GASES
FEEDBACK
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NONMETALS
OXYGEN
POROSITY
SIGNALS
SOLID ELECTROLYTES
WASTES