| 摘要 |
PROBLEM TO BE SOLVED: To enhance the cooling performance of an EGR valve by forming a valve guide cooling passage part for circulating cooling liquid around a valve guide, and an actuator cooling passage part for circulating a cooling liquid around a hydraulic actuator on a housing which defines an EGR passage. SOLUTION: Cooling water forcedly fed from a water pump, flows into a valve guide cooling passage part 21 through an inlet passage 23 opened to a housing 2, circulates in an actuator cooling passage part 22 through a succeeding connecting passage 24, and then it is sent out to a radiator through an outlet passage 25. Although an EGR valve 1, a bush 8, and the housing 2 are exposed to EGR gas, the heat of a valve guide 5 is absorbed by cooling water passing through the valve guide cooling passage 21, and the bush 8 or the housing 2 is prevented from being overheated. Furthermore, the heat of a pneumatic cylinder 6 is absorbed by cooling water passing through the actuator cooling passage 22, and a guide part 34 or a seal 35 is prevented from being overheated.
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