Need-based method of heating a catalyst in the exhaust system of an internal combustion engine
AssigneeRobert Bosch GmbH
InventorRuediger Becker
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Abstract
A need-based method of heating a catalyst in the exhaust-gas system of an internal combustion engine, in which a converting power of the catalyst is determined and the catalyst is heated as a function of the converting power. Depending on the operating conditions of the internal combustion engine, different measures are undertaken for the heating of the catalyst. If the heating measures do not lead to the desired results within a predetermined time interval, a diagnostic function is started. As part of the diagnostic function, particularly effective heating measures are applied. If while using these measures a sufficient converting power of the catalyst is not obtained within a predetermined second time interval, it is assumed that the catalyst is damaged.
Claims12
A method of heating a catalyst in an exhaust-gas system of an internal combustion engine, the method comprising the steps of:
- measuring at least two values, with at least one value representative of a condition before conversion by the catalyst and at least one value representative of a condition after conversion by the catalyst;
- determining a converting power of the catalyst from the at least two measured values;
- and
- heating the catalyst as a function of the converting power of the catalyst,
- wherein the heating step includes heating the catalyst using a first set of measures if a lambda control of the internal combustion engine is not active and terminating the first set of measures as a result of the occurrence of an event selected from the group of events consisting of:
- an activation of the lambda control,
- an expiration of a first time interval since a starting of the internal combustion engine,
- an expiration of the first time interval since a deactivation of the lambda control,
- a surpassing of a first load integral threshold value by a load integral integrated since the starting of the internal combustion engine, and
- a surpassing of the first load integral threshold value by a load integral integrated since the deactivation of the lambda control.
A method of heating a catalyst in an exhaust-gas system of an internal combustion engine, the method comprising the steps of:
- measuring at least two values, with at least one value representative of a condition before conversion by the catalyst and at least one value representative of a condition after conversion by the catalyst;
- determining a converting power of the catalyst from the at least two measured values;
- and
- heating the catalyst as a function of the converting power of the catalyst,
- wherein the heating step includes different sets of measures for heating the catalyst depending on at least one operating condition of the internal combustion engine.
A device for heating a catalyst in an exhaust gas system of an internal combustion engine, the device comprising:
- at least two sensors for measuring at least two values, with at least one value representative of a condition before conversion by the catalyst and at least one value representative of a condition after conversion by the catalyst;
- means for determining a converting power of the catalyst from the at least two values;
- and
- means for heating the catalyst as a function of the converting power of the catalyst;
- wherein the means for heating the catalyst performs different sets of measures for heating the catalyst depending on at least one operating condition of the internal combustion engine.
Dependencies are inferred from the claim text.