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U.S. Department of Energy
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Air/fuel ratio control system including means to well time start of feedback

Patent ·
OSTI ID:5850683

A control system for feedback control of the air/fuel ratio of an air-fuel mixture supplied to an internal combustion engine is described comprising: an oxygen sensor which is disposed in an exhaust passage of the engine and comprises a first solid electrolyte cell, reference means for maintaining a reference gas atmosphere, measurement means for defining a space which provides access to the measurement electrode for gases and restrictively admitting a fraction of the exhaust gas of the engine into the space and a second solid electrolyte cell having an oxygen ion conductive solid electrolyte layer provided with a pair of electrodes in such an arrangement that an externally supplied pumping current flows through the solid electrolyte layer to cause migration of oxygen ions therethrough and to thereby cause a change in the partial pressure of oxygen in the space; sensor means to detect the temperature of the engine; means for outputting a detection start signal after the lapse of a predetermined length of time from the start of the engine; detection means for supplying the pumping current to the second solid electrolyte cell in the oxygen sensor while controlling the pumping current so as to render the output voltage of the first solid electrolyte cell equal to a target value and producing an air/fuel ratio signal which is representative of the magnitude of the controlled pumping current; control means for producing and outputting an air/fuel mixing ratio control signal based on the air/fuel ratio signal.

Assignee:
Nissan Motor Co., Ltd., Yokohama City
Patent Number(s):
US 4707241
OSTI ID:
5850683
Country of Publication:
United States
Language:
English