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AssigneeIsuzu Motors Limited
InventorsHitoshi Sato, Naofumi Ochi, Masashi Gabe, Takehito Imai
Estimating the term…
To provide an exhaust gas purifying method for purifying the exhaust gas of an internal combustion engine (1) by an exhaust gas purifying system (10) having an oxidation catalyst (3a), which comprises the steps of estimating the quantity of unburnt hydrocarbon accumulated in a support of the oxidation catalyst (3a), performing a hydrocarbon removal control when an estimated accumulation quantity (Vhc) of the unburnt hydrocarbon exceeds a predetermined judgment value (Vhc0) and raising an exhaust gas temperature (T) to activate the oxidation catalyst (3a) and oxidizing and removing the accumulated unburnt hydrocarbon. Thereby, it is possible to prevent a white fume from being produced after a low exhaust temperature state of an idling operation or the like continues for a long time.
An exhaust gas purifying method for purifying exhaust gas of an internal combustion engine by an exhaust gas purifying system having an oxidation catalyst, comprising the steps of:
An exhaust gas purifying system having an oxidation catalyst to purify the exhaust gas of an internal combustion engine, comprising an accumulated-hydrocarbon-quantity judgment means for estimating the quantity of unburnt hydrocarbon accumulated in an oxidation catalyst carrier and judging whether the estimated accumulation quantity of unburnt hydrocarbon exceeds a predetermined judgment value, and a hydrocarbon removal control means for activating the oxidation catalyst by raising an exhaust gas temperature when the accumulated-hydrocarbon-quantity judgment means judges that the estimated accumulation quantity exceeds the predetermined judgment value, and oxidizing the accumulated unburnt hydrocarbon to remove.
Dependencies are inferred from the claim text.