Patent ID: 7350350

Claim:
An exhaust gas purifying apparatus for an internal combustion engine comprising: a diesel particulate filter provided in an exhaust pipe of the engine for trapping diesel particulates contained in exhaust gas emitted from the engine; and an electronic control unit for controlling a re-generation operation of the diesel particulate filter, wherein the electronic control unit controls in such a manner that: the diesel particulate filter is hypothetically divided into multiple cells, which are sequentially arranged in a direction of exhaust gas flow, a temperature presuming point is hypothetically set in each of the cells, a temperature at the temperature presuming point is presumed by calculating a heat budget for the cell without directly detecting the temperature of the cell, a maximum temperature of the diesel particulate filter is presumed from the multiple presumed temperatures at the respective temperature presuming points, and the temperature of the diesel particulate filter is controlled in a way that the presumed maximum temperature may not become higher than a predetermined value, wherein the temperature at the respective temperature presuming points is presumed based on an outside information of the exhaust gas flowing into the diesel particulate filter and an inside information of the diesel particulate filter; the outside information comprises at least one of the followings; an amount of the exhaust gas flowing into the diesel particulate filter; a temperature of the exhaust gas flowing into the diesel particulate filter; and an amount of hydrocarbons flowing into the diesel particulate filter, and the inside information comprises at least one of the followings; an accumulated amount of the diesel particulates around the respective temperature presuming points; and an amount of hydrocarbons around the respective temperature presuming points.