Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Mikio Terada

Kazuya Oohashi

Kiyoshi Hatano

Tetsuo Chamoto

Manabu Morimoto

Hiroki Taniguchi

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.

Exhaust emission control device

An exhaust emission control device comprises an oxidizing catalyst, a particulate filter on which soot is deposited, and a temperature sensor for detecting the temperature of exhaust gas on the upper-stream side of the filter. An intake system of an engine is provided with an EGR valve for returning the exhaust gas to the intake system. If the temperature of the oxidizing catalyst is found to be lower than its active temperature as the particulate filter is regenerated, the catalyst is heated by delaying the injection timing for the main fuel injection of the engine and increasing the EGR gas reflux quantity. Thus, the oxidizing catalyst can be heated up without lowering the fuel-efficiency, and soot on the particulate filter can be efficiently subjected to re-combustion.

Exhaust emission control device of engine

A control unit activates regeneration assist means, if a specific operating state involving incomplete combustion of particulates by NO continues for a predetermined period or more, as a first determination condition, and controls an exhaust gas temperature or a temperature of a catalyst to enhance the conversion efficiency of the catalyst into NO , thereby continuously regenerating the particulates. The control unit activates forced regeneration means, if a deposited amount of particulates detected by deposited amount detecting means exceeds a predetermined value, as a second determination condition, and controls the exhaust gas temperature or a temperature of a filter to be higher than that of when the regeneration assist means is activated to forcibly regenerate the filter. The control unit activates either the forced regeneration means or the regeneration assist means in accordance with the temperature sensed by temperature sensing means, if the first and second determination conditions are simultaneously established.

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Shiga, Japan

Mikio Terada