Air-fuel ratio control system
Patent 4251990 Issued on February 24, 1981. Estimated Expiration Date: 
July 20, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 20, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3782347 3875907 Engine with dual sensor closed loop fuel control Control system for normalizing the air/fuel ratio in a fuel injection system Internal combustion exhaust catalytic reactor monitoring system Fuel control system with calibration learning capability for motor vehicle internal combustion engine Patent #: 4130095 InventorsAssigneeApplicationNo. 06/059328 filed on 07/20/1979US Classes:60/276, Having means analyzing composition of exhaust gas123/691, Multiple sensors controlling group of cylinders60/285Engine fuel, air, or ignition controlled by sensor of reactor conditionExaminersPrimary: Hart, DouglasAttorney, Agent or FirmInternational ClassF02D 41/14 (20060101)Foreign Application Priority Data1978-09-05 JPAbstractAn air-fuel ratio control system comprises a first oxygen concentration detector arranged upstream of a three-way catalyst for purifying the exhaust gas in the exhaust system of an internal combustion engine, a second oxygen concentration detector arranged downstream of the three-way catalyst, a discrimination circuit for detecting and discriminating a specific operating condition of the internal combustion engine in response to a signal representing operating factors of the internal combustion engine such as the amount of intake air and vehicle speed, and a change-over circuit impressed with the signals from the first and second oxygen concentration detectors. The change-over circuit produces selectively the detection signal of the second oxygen concentration detector in response to the output signal of the discrimination circuit only when the discrimination circuit detects a predetermined operating condition of the internal combustion engine, and the detection signal of the first oxygen concentration detector when the internal combustion engine is under the other operating conditions.Field of SearchHaving means analyzing composition of exhaust gas | |
