Apparatus and method for controlling vehicle so as to purify exhaust emission from engine

摘要

Method and apparatus for controlling a vehicle so as to purify an exhaust emission from an internal combustion engine (1) with an exhaust-emission purifying catalyst (5) disposed in an exhaust system of the engine (1), and such that the engine (1) is brought into a temporary engine-stop state while a predetermined vehicle condition is satisfied, wherein the engine (1) is operated for heating the catalyst (5), when a temperature of the catalyst (5) has been lowered below a predetermined lower limit threshold (Tcc1), even while the predetermined vehicle condition is still satisfied. The catalyst (5) maintains an exhaust-emission purifying ability at a temperature above the lower limit threshold. When the catalyst temperature has been raised to a predetermined upper limit threshold (Tcc2), as a result of the engine operation, the engine (1) is restored to the temporary engine-stop state if the predetermined condition is still satisfied. The present method and apparatus permit the catalyst temperature to be held at a level higher than the activation lower limit (Tcc1), while minimizing the reduction of an effect of the temporary engine stop in an economy-running-system vehicle or hybrid vehicle.