| 摘要 |
PROBLEM TO BE SOLVED: To reduce harmful exhaust gases and prevent harnesses, cords, hoses, or the like arranged in the surrounding from being thermally damaged, by providing a first cooling means on the outer part of the pipe wall of an EGR duct, a second cooling means on the outer part of the nearby pipe wall of an EGR valve, and a third cooling means on the outer part of the pipe wall of an EGR pipe respectively. SOLUTION: A first water jacket 9 as a first cooling means is formed on an EGR duct 7, provided additionally on a first EGR pipe 6 connected to an exhaust manifold 4 provided on the exhaust side 2e of an engine via a block 3, and a second water jacket 14 as a second cooling means is connected thereto. A second EGR pipe 13 is contained in a third water jacket 18 as a third cooling means, and an EGR valve 8 is interposed on the way of the EGR duct 7. EGR gas flowing in the EGR duct 7 is cooled by cooling water in the first water jacket 9, and the EGR valve 8 in the duct 7 is cooled by cooling the water which flows into the second water jacket 14 provided on the outer circumferential part in its vicinity.
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