EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To prevent fine particles remained in a particulate filter from being discharged to the external in the operation of a switching valve in an exhaust emission control device where the exhaust gas is allowed to be alternately switched and passed to exhaust upstream and downstream parts with respect to the particulate filter with a catalyst. SOLUTION: This exhaust emission control device comprises the particulate filter 22 carrying an active oxygen emissive agent and capable of temporarily capturing the fine particles in the exhaust gas, and a control means for operating an exhaust switching means for alternately switching a first flow for flowing the exhaust from one side and a second flow for flowing the exhaust gas from the other side. The switching of the exhaust is executed after a temperature rising means is operated when a temperature judging means of the particulate filter 22 judges that the filter 22 does not reach a temperature for oxidizing the fine particles. When it is judged that the particulate filter 22 does not reach the temperature for oxidizing the fine particles, the switching of the exhaust is stopped until a predetermined time has passed after the start of an internal combustion engine 1.