| 摘要 |
PURPOSE: To prevent a seat section from adhering on a valve seat member closely in advance by not closing a valve element completely and holding it at a predetermined small degree of opening after an engine stops. CONSTITUTION: When an engine stops, a control unit makes a valve element 26 apart from a valve seat member 28 slightly through a stepping motor and sets a degree of opening of an EGR control valve to a predetermined small degree of openingθ. After that, electricity is not supplied to the stepping motor, but the position of the valve element 26 is held due to detent torque of the stepping motor against spring force of a valve spring 30. Consequently, it is possible to prevent a seat part 26C from adhering on the valve seat member 28.
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