| 摘要 |
A proportional flow control valve includes an electromagnetic actuator which controls the displacement of an elongate member such as a leaf spring with respect to two or more fluid conveying apertures aligned with the member to achieve a fluid flow proportional to the current applied to the actuator. One portion of the member is displaced with respect to another portion of the member by the electromagnetic actuator in order to selectively open an outlet aperture and one or more of the inlet apertures occluded by the member, achieving a desired fluid flow. A firm-off stopper for occluding the output aperture may be attached near the point of connection between the actuator and the member to assure that the flow through the valve is completely terminated when the valve is in the "off" position. The member may be fixed at one end or it may be free at two ends with a selectively positionable intermediate weight arranged to adjust the rate of displacement of the ends of the member with respect to the apertures. In one embodiment, a tapered variable flow valve stem, attached to the member between the stopper and the pivot point of the member, is arranged to variably occlude an inlet aperture according to the position of the member.
|
