Patent attributes
A low pressure EGR system includes a low pressure EGR passage connecting a downstream portion of an exhaust gas cleaner disposed in an exhaust passage to an upstream portion of a supercharger compressor disposed in an intake passage. A device for trapping foreign particles contained in EGR gas to be recirculated is disposed in the low pressure EGR passage. The trapping device may be positioned lower than the passage connected thereto so that foreign particles drop into the device by their own weight. A cross-sectional area of the trapping device may be made larger than that of the passage so that the flow speed of the EGR gas is reduced in the trapping device and the foreign particles are easily trapped. A valve for closing the low pressure EGR passage may be disposed therein to stop EGR when malfunctions are detected in the exhaust gas cleaner or the supercharger.