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US 4,730,590 AGranted
Air-fuel ratio control system for an engine
AssigneeFuji Jukogyo Kabushiki Kaisha
InventorYoshiyuki Sogawa
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Abstract
An air-fuel ratio feedback control system is provided with a look-up table storing a plurality of time data dependent on an engine operating condition. The time is decided to correspond to a control delay time of the control system. When a desired air-fuel ratio varies, feedback operation is stopped for a time derived from the look-up table.
Claims4
An air-fuel ratio control system for an engine, comprising sensing means for sensing engine operating conditions and for producing operating condition signals;
- a sensor sensing oxygen concentration of exhaust gas of the engine and producing a feedback signal dependent on the concentration;
- first means responsive to the operating condition signals for producing a desired air-fuel ratio signal;
- second means for comparing the feedback signal with the desired air-fuel ratio signal and for producing an error signal;
- control means responsive to the error signal for deciding amount of fuel supplied to the engine;
- third means for detecting variation of the desired air-fuel ratio and for producing a variation signal;
- a look-up table storing a plurality of time period data dependent on an engine operating condition, the time period being decided to correspond to a control delay time of the control system;
- fourth means responsive to the variation signal for fixing the error signal for a time period derived from the look-up table.
4 more elements
Dependencies are inferred from the claim text.