| 摘要 |
In an EGR valve, a valve element is seatable on a valve seat by stroke movement of a valve stem caused by an actuator. The valve seat has a cylindrical part with which a step of the stem is engageable. By the stroke movement of the valve stem, the opening degree between the valve seat and the valve element is changed. The valve seat is moved in the passage in the stroke movement direction to be engageable with a shoulder of the passage. As the valve element is moved together with the stem, the opening degree in the low opening range is changed. As the step of the stem is engaged with the cylindrical part and the valve seat is moved with respect to the shoulder, the opening degree in the high opening range is changed. |
