Exhaust emission control device

摘要

An exhaust emission control device has operating condition detecting means for detecting an operating condition of an engine, fuel control means for controlling fuel supply into a combustion chamber of the engine on the basis of an output of the operating condition detecting means, a turbo charger for supercharging a suction air with an exhaust gas of the engine, wherein a filter for capturing particulates in the exhaust gas is disposed in an exhaust gas passage on the downstream side of a turbine of the turbo charger, and the filter holds alkaline metal catalyst. Exhaust gas temperature sensing means senses (or estimates) the exhaust gas temperature near the filter, and supercharging pressure control means controls a supercharging pressure of the turbo charger to be increased when the exhaust gas temperature exceeds a predetermined temperature.