Method and arrangement for controlling the fuel for an internal combustion engine having a catalyzer
AssigneeRobert Bosch GmbH
InventorNikolaus Benninger
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Abstract
The arrangement according to the invention permits the optimal control of the air/fuel ratio of an air/fuel mixture supplied to an internal combustion engine while considering the gas storage capability of a catalyzer. The degree of conversion of the catalyzer is dependent upon the oxygen content of the exhaust gas which is available. Since this degree of conversion is partially influenced by the oxygen given off by the catalyzer, a targeted enrichment or leaning of the air/fuel ratio can optimize the degree of conversion of the catalyzer.
Claims11
A method for controlling the air/fuel ratio of an air/fuel mixture supplied to an internal combustion engine equipped with a catalyzer having a gas storage capability, the method comprising the steps of:
- utilizing at least one lambda probe arranged in the exhaust gas system of the engine upstream of the catalyzer;
- enriching and leaning the air/fuel ratio about a pregiven desired value .lambda..sub.s by forming the difference .DELTA..lambda. of the value .lambda. measured by said lambda probe and the desired value .lambda..sub.s integrating said difference to form a value of the integral function (FL) of said difference as a function of time;
- and,
- controlling the value of the integral function (FL) of this difference to a pregiven value (IS) over the time for a pregiven time interval.
An arrangement for controlling the air/fuel ratio of an air/fuel mixture supplied to an internal combustion engine having an exhaust gas system, the arrangement comprising:
- catalyzer mounted in the exhaust gas system and having a gas storage capability for storing oxygen;
- a lambda probe mounted in said system upstream of said catalyzer;
- and,
- controller means for effecting a targeted enrichment and leaning of the air/fuel ratio about a pregiven desired value .lambda..sub.s by forming the difference .DELTA..lambda. of the value .lambda. measured by said lambda probe and the desired value .lambda..sub.s ;
- integrator means for forming a value of the integral function (FL) of said difference as a function of time;
- and,
- integral controller means for controlling said value of said integral function to a pregiven value (IS) over the time for a pregiven time interval.
Dependencies are inferred from the claim text.