Patent ID: 6526954
Filing Date: 2003-03-04
Classification: F02D

Abstract:
A regulating system for regulating an air-fuel mixture in an internal combustion engine including a plurality of cylinders, connected to an exhaust gas system including at least one point where exhaust gases from at least two of the cylinders are joined, the regulating system comprising:a first binary sensor arranged for sensing the exhaust gases and producing a first output signal having a switching point from a first output signal level to a second output signal level, where the first output signal level is stable for so long as the air-fuel mixture is the exhaust gases is lean, and where the second output signal level is achieved when the air-fuel mixture in the exhaust gases is rich, the first binary sensor being located at the at least one point; and an engine control unit comprising first means for regulating the amount of fuel delivered to each of the plurality of cylinders in the engine depending upon at least one actual engine parameter, and applying a correction to the amount of delivered fuel depending on the first output signal from the first binary sensor; second means for matching from which of the plurality of cylinders the sensed exhaust gases derive, third means for detecting a pulse width of the second output signal level of the first output signal and storing the pulse width as a first value in a memory as a combustion-related value; fourth means arranged for ascertaining a level of richness of the air-fuel mixture in the exhaust gases in relation to the first value as well as actual operating conditions of the engine, including engine rotation speed provided by an engine rotation speed sensor; and fifth means for reducing the amount of delivered fuel to only that of the plurality of cylinders which after matching is indicated as having a rich mixture in the exhaust gases.