| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide technology making control for raising temperature of an oxidation catalyst by raising exhaust gas temperature of an internal combustion engine before supplying fuel to the oxidation catalyst unnecessary and enabling to perform regeneration treatment of a filter at arbitrary timing in an exhaust emission control system for an internal combustion engine provided with the oxidation catalyst in an exhaust gas passage of the internal combustion engine and provided with a filter on a downstream side of the oxidation catalyst and performing regeneration treatment of the filter by raising temperature of the filter by supplying fuel to the oxidation catalyst. <P>SOLUTION: A bypass passage making exhaust gas discharged from the internal combustion engine bypass the oxidation catalyst is provided. During a period except a period performing the regeneration treatment, exhaust gas from the internal combustion engine is made to pass through the oxidation catalyst to raise and keep temperature of the oxidation catalyst (S105) if the exhaust gas temperature is a predetermined temperature or higher, and exhaust gas from the internal combustion engine is made to pass through the bypass passage to keep the oxidation catalyst warm (S106) if the exhaust gas temperature is lower than the predetermined temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
