| 摘要 |
PROBLEM TO BE SOLVED: To prevent accumulation of condensate in a pendent portion even if an EGR (exhaust gas recirculation) pipe is horizontally laid whereby the pendent portion is formed due to arrangement restriction on a catalyst or the like. SOLUTION: This exhaust gas recirculation device is provided with an exhaust emission control device such as a DPF (diesel particulate filter) and a NOx occlusion reducing catalyst arranged in an exhaust gas passage, and the exhaust gas recirculation pipe for recirculating exhaust gas from the downstream position of the exhaust emission control device to the intake side of an internal combustion engine. Since the exhaust gas recirculation pipe configured to take out the exhaust gas from the downstream side of the exhaust emission control device has a long passage, the condensate is easily accumulated by the influence of outside air temperature or the like. Since a communication passage communicated with an exhaust gas passage is provided in the vicinity of the lowermost portion of the exhaust gas recirculation pipe, the condensate in the exhaust gas recirculation pipe is delivered to the exhaust gas passage through the communication passage. Meanwhile, when pressure of the exhaust gas passage is increased, exhaust gas is led to flow from the exhaust gas passage into the exhaust gas recirculation pipe to cause malfunction such as unstable exhaust gas recirculation control when the communication passage is opened. Therefore, a communication passage valve is arranged in the communication passage, and the communication passage is disconnected when need. COPYRIGHT: (C)2008,JPO&INPIT
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