Mitsubishi Denki Kabushiki Kaisha

Li Liu

Satoshi Wachi

Hiromichi Hisato

Hideaki Katashiba

To obtain an exhaust gas purification method for an internal combustion engine for detecting timing at which an inflow NOx amount flowing into an NOx absorption catalyst exceeds an NOx amount processable by the NOx absorption catalyst, and enriches the air/fuel ratio to prevent deterioration of the exhaust gas and maintain good fuel consumption. Based on an NOx amount absorbed in the NOx absorption catalyst and a maximum NOx absorption amount NOx of the absorption catalyst, a processable NOx amount processable by the NOx absorption catalyst per unit time is calculated and compared with the inflow NOx amount entering the NOx absorption catalyst per unit time, and when it is determined that the inflow NOx amount is greater, the air/fuel ratio is switched to rich.

Exhaust gas purification method for internal combustion engine

An air/fuel ratio correction cylinder determining section specifies, based on the peak phase, a cylinder for which an air/fuel ratio is to be corrected. A cylinder-specific air/fuel ratio correcting section in the form of respective cylinder correcting sections through corrects an amount of fuel to be supplied to a cylinder which becomes an air/fuel ratio correction target. A cylinder for which an air/fuel ratio deviates from the remaining cylinders is specified as a fuel amount correction target based on a change in the output value of the air/fuel ratio sensor.

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Hyogo, Japan

Li Liu