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AssigneeToyota Jidosha Kabushiki Kaisha
InventorsTakamitsu Asanuma, Kohei Yoshida, Hiromasa Nishioka, Daichi Imai, Kazuhiro Umemoto
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In an exhaust purification system of an internal combustion engine, comprising a NOX catalyst device, which can satisfactorily store NOX in the exhaust gas when the concentration of oxygen in the exhaust gas is high and can release the stored NOX and purify the released NOX to N2 by reducing materials in the exhaust gas when the concentration of oxygen is decreased as a regeneration treatment, the regeneration treatment is carried out to change a combustion air-fuel ratio from a lean air-fuel ratio to a set rich air-fuel ratio, and N2O reducing material is supplied to the NOX catalyst device during at least one of a first period set within a period in which an air-fuel ratio in the exhaust gas within said NOX catalyst device changes from the lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started and a second period set within a period after an air-fuel ratio in the exhaust gas within the NOX catalyst device becomes the stoichiometric air-fuel ratio when the regeneration treatment is finished.
An exhaust purification system of an internal combustion engine, comprising a NOX catalyst device which can satisfactorily store NOX in the exhaust gas when the concentration of oxygen in the exhaust gas is high and can release the stored NOX and purify the released NOX to N2 by reducing materials in the exhaust gas when the concentration of oxygen is decreased as a regeneration treatment, wherein said regeneration treatment is carried out to change a combustion air-fuel ratio from a lean air-fuel ratio to a set rich air-fuel ratio, and N2O reducing material is supplied to said NOX catalyst device during at least one of a first period set within a period in which an air-fuel ratio in the exhaust gas within said NOX catalyst device changes from said lean air-fuel ratio to said set rich air-fuel ratio when said regeneration treatment is started and a second period set within a period after an air-fuel ratio in the exhaust gas within said NOX catalyst device becomes the stoichiometric air-fuel ratio when said regeneration treatment is finished.
An exhaust purification system of an internal combustion engine as set forth in 2 wherein said N2O reducing material is fuel with a higher boiling point than that of HC included in the exhaust gas during said regeneration treatment.
An exhaust purification system of an internal combustion engine as set forth in 3 wherein said N2O reducing material is fuel with a higher boiling point than that of HC included in the exhaust gas during said regeneration treatment.
Dependencies are inferred from the claim text.