Air/fuel ratio control system for an internal combustion engine with a function for preventing the blackening phenomenon of oxygen concentration sensor

Patent · Tue Mar 22 04:00:00 EST 1988

OSTI ID:5004376

Kawanabe, T; Asakura, M; Kimura, K; Muroya, M

An air/fuel ratio control system for an internal combustion engine is described comprising: an air supply passage connected to an air intake system of the internal combustion engine, for varying the air/fuel ratio of the mixture to be supplied to the engine; an open/close valve disposed in the air supply passage for controlling the air flow in the air supply passage; an oxygen concentration sensing unit disposed in an exhaust gas of the internal combustion engine; current supply means for supplying a pump current across the electrodes of the oxygen pump element so as to keep constant voltage generated across the electrodes of the sensor cell element thereby causing the sensing unit to monitor a magnitude of the pump current which is substantially in proportion to the oxygen concentration in the exhaust gas; valve open time period control circuit means connected to the oxygen concentration detection device; valve drive means connected to the valve open time period control circuit means for opening the open/close valve for the calculated valve open time period in each of the cycles; and control means responsive to output signals of the current supply means and the valve open time period control circuit means for stopping the supply of the pump current across the electrodes of the oxygen pump element when the valve open time period calculated by the valve open time period control circuit means exceeds a predetermined upper limit of valve open time period.

• Assignee: Honda Giken Kogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4732127
• OSTI ID: 5004376
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
AIR FLOW
CONTROL
CONTROL EQUIPMENT
CONTROL SYSTEMS
DETECTION
ELEMENTS
ENGINES
EQUIPMENT
EXHAUST SYSTEMS
FLOW REGULATORS
FLUID FLOW
FUEL SYSTEMS
FUEL-AIR RATIO
GAS FLOW
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERING
METERS
NONMETALS
OPERATION
OXYGEN
PUMPS
VALVES