| 摘要 |
PROBLEM TO BE SOLVED: To effectively purify exhaust gas by reducing the quantity of soot and Raw NOx discharged from the combustion chamber of an engine. SOLUTION: In this exhaust emission control device of the engine, having a NOx-purifying catalyst 22 for purifying NOx, and a reducing agent quantity increasing means 38 for increasing quantity of a reducing agent, supplied to the NOx purifying catalyst 22 by injecting fuel in the prescribed timing up to an exhaust stroke from an expansion stroke, an active state determining means 37 is provided for determining whether the NOx-purifying catalyst 22 is in an active state; and the exhaust emission control device of the engine and this fuel injection timing setting method are constituted, such that when this active state determining means 37 determines that the NOx purifying catalyst 22 is in inactive state, the fuel injection timing controlled by the reducing agent quantity increasing means 38 is made to advance further than the case, where the NOx purifying catalyst 22 is in the active state. |
