Patent ID: 6209316
Filing Date: 2001-04-03
Classification: B01D,F01N,F02B,F02D

Abstract:
A method of operating a diesel engine having an engine controller which controls the operation of the diesel engine as a function of characteristic maps and permits rich/lean control of the diesel engine, wherein the engine controller comprises a computer which effects a changeover to rich or lean operation of the diesel engine as a function of predetermined changeover criteria, a sensor system which communicates with the computer and monitors parameters needed for changeover criteria, and a memory which communicates with the computer and in which the characteristic maps for operating the diesel engine are stored, comprising:effecting a changeover with the computer from lean to rich operation only when all the following changeover criteria are satisfied:a regeneration temperature of a storage catalytic converter element through which the exhaust gases from the diesel engine flow is maintained, anda predetermined level of adsorption of the storage catalytic converter element through which the exhaust gases from the diesel engine flow is present, andeffecting a change back with the computer from rich to lean operation when any of the following changeover criteria is satisfied:the changeover criteria for a changeover from lean to rich operation is absent,a regeneration time, which depends on the respective level of adsorption of the storage catalytic converter element through which the exhaust gases from the diesel engine flow, expires at the beginning of the rich operating phase,a predetermined level of desorption of the storage catalytic converter element through which the exhaust gases from the diesel engine flow is present,a predetermined reducing-agent content in the exhaust gases downstream of the storage catalytic converter element is present, or an exhaust-gas temperature below a predetermined threshold value is present.