Exhaust emission control device

An exhaust emission control device comprising:

• 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 in accordance with an exhaust gas of the engine;
• a filter for capturing particulates in the exhaust gas, the filter holding alkaline metal catalyst and disposed in an exhaust gas passage on the downstream side of a turbine of the turbo charger;
• exhaust gas temperature sensing means for sensing the exhaust gas temperature near the filter;
• and
• supercharging pressure control means for controlling a supercharging pressure of the turbo charger to be increased when the exhaust gas temperature sensed by the exhaust gas temperature sensing means exceeds a predetermined temperature wherein the operating condition sensing means has load change rate detecting means for detecting the rate of change for the load of the engine, in which the supercharging pressure control means controls the supercharging pressure of the turbo charger to be increased when the exhaust gas temperature sensed by the exhaust gas temperature sensing means exceeds the predetermined temperature and the rate of change for the engine load detected by the load change rate detecting means is a positive value.

An exhaust emission control device comprising:

• 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 in accordance with an exhaust gas of the engine;
• a filter for capturing particulates in the exhaust gas, the filter holding alkaline metal catalyst and disposed in an exhaust gas passage on the downstream side of a turbine of the turbo charger;
• exhaust gas temperature sensing means for sensing the exhaust gas temperature near the filter;
• and
• supercharging pressure control means for controlling a supercharging pressure of the turbo charger to be increased when the exhaust gas temperature sensed by the exhaust gas temperature sensing means exceeds a predetermined temperature wherein the exhaust gas passage has oxidation catalyst disposed on the upstream side of the filter and on the downstream side of the turbine.