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专利名称：Method and arrangement for determining
the performance loss of a catalyzer
发明人：Erich Schneider,Eberhard Schnaibel申请号：US07/870263申请日：19920417公开号：US05267472A公开日：19931207
摘要：The invention relates to a method for determining the performance loss of acatalyzer receiving the exhaust gas of a lambda- controlled internal combustion engineand includes the steps of: measuring lambda values forward and rearward of thecatalyzer to obtain forward and rearward lambda values, respectively; when a controloscillation of the forward lambda value makes a transition from rich to lean or from leanto rich, determining if the rearward lambda value makes a transition corresponding to thetransition of the forward lambda value, and if this correspondence takes place, thencarrying out the following additional steps: determining the gas mass flow flowingthrough the catalyzer; computing the time integral of the product of the gas mass flowand the forward lambda value; computing the time integral of the product of the gasmass flow and the rearward lambda value; and, as a measure of the performance loss ofthe catalyzer, utilizing either the difference between the integrals or the quotient of theintegrals or the quotient of the difference and one of the integrals. The method of theinvention affords the advantage that determinations are only undertaken when it isensured that the catalyzer is entirely filled with oxygen or is completely emptied inadvance of a measurement. This achieves well defined starting relationships.
Furthermore, the advantage is provided that with the evaluations, gas-mass flows areconsidered which permits the storage capacity of the catalyzer for oxygen to be directlydetermined. This oxygen storage capacity is the variable decisive in the practice fordetermining the state of deterioration of the catalyzer.
申请人：ROBERT BOSCH GMBH
代理人：Walter Ottesen
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