A rotational moving point of a connection between a rod and a valve swings between a full open point, at which the valve is fully opened, and a full close point, at which the valve is fully closed. An apex of this swing is set at a point, which is between the full close point and a half point and satisfies a relationship of θP>θA where θP denotes an angle that is defined between a first imaginary line, which connects between a bearing center of a rod bearing and the full open point, and a second imaginary line, which connects between the bearing center and the apex of the swing, and θA denotes an angle that is defined between the first imaginary line and a third imaginary line, which connects between the bearing center and the full close point.