Abstract: An exhaust emission control device including a selective reduction catalyst; urea water as reducing agent being added in the pipe upstream of the reduction catalyst depurate NOx through reduction; an oxidation catalyst arranged in the pipe upstream of an added position of the urea water, the oxidation catalyst physically adsorbing NOx in the exhaust gas at a temperature lower than a lower active limit temperature of the reduction catalyst and discharging the adsorbed NOx at a temperature higher than a lower active limit temperature of the oxidation catalyst; and a fuel injection device for adding fuel into the exhaust gas upstream of the oxidation catalyst is disclosed. The start of the fuel addition by the fuel injection device is refrained until exhaust temperature on an inlet side of the reduction catalyst is increased to a preset temperature comparable with the lower active limit temperature of the oxidation catalyst.

Abstract: Related is a method for regeneration of a particulate filter 6 wherein manual regeneration of the particulate filter 6 started with a vehicle being stopped causes an exhaust brake 14 to throttle an exhaust passage. This increases an engine load and a fuel injection amount to elevate in temperature an exhaust gas 3; then, fuel addition is started by post injection with a fuel injection device 10, and the particulate filter 6 is regenerated by heat of an oxidation reaction of the added fuel on an oxidation catalyst 5 . After the starting of the manual regeneration, whether a fuel injection amount exceeds a reference value or not is judged. Only if the judgment is affirmative, throttling of the exhaust passage by the exhaust brake 14 is released provided exhaust temperature exceeds a reference temperature on an entry side of the particulate filter 6.

Abstract: The invention has an object of exerting favorable NOx reducing effects even at an exhaust temperature lower than in the prior art without trouble, e.g., at startup after long-term engine rest and is directed to an exhaust emission control device wherein a selective reduction catalyst 5 capable of selectively reacting NOx with ammonia even in the presence of oxygen is incorporated in an exhaust pipe 4, urea water 6 as reducing agent being added in the pipe 4 upstream of the reduction catalyst 5 to depurate NOx through reduction.