Patent ID: 7395659
Filing Date: 2008-07-08
Classification: B60K,B60W,F02D,Y02T

Abstract:
1. A method for operating a hybrid vehicle comprising an internal combustion engine, at least one electric motor, each for the output of a torque to at least one vehicle wheel, and an exhaust gas system having a catalytic converter system for at least one exhaust gas component assigned to the internal combustion engine, wherein the catalytic converter system contains at least one precatalytic converter located close to the engine and at least one main catalytic converter arranged downstream of the precatalytic converter, wherein a conversion activity of the catalytic converter system is dependent on predetermined activity parameters, the method comprising the steps of: determining the value of the conversion activity for attaining a predetermined conversion threshold of the conversion activity for at least one exhaust gas component in a predetermined time interval; and if the value lies below said threshold, then increasing the torque output of the electric motor, and reducing the torque output of the internal combustion engine as compared to an operation of the hybrid vehicle without the provision of a torque by the electric motor, wherein the combined torque delivered by the internal combustion engine and the electric motor is used to drive the hybrid vehicle; wherein the internal combustion engine is a direct-injection gasoline capable of stratified-charge capable of lean-burn and the precatalytic converter having a lowered precious metal content is subjected to an oven aging process for 4 hours at 1100° C. in an atmosphere of 2% O