Ventil

摘要

In a flow control valve, particularly a vacuum valve, a magnetic force (F) in the closing direction is generated between a closure member (14) and a stationary member (10) of the valve, at least in the closure lift region, by means of a magnetic system (18). The closing force (F), produced by a magnetic field of the system (18) in an air gap (L), decreases with increasing opening lift (x), in contrast to the force produced by a closing spring. The magnetic system may be a permanent magnet (Fig. 2) or a solenoid (18a) controlled by a position sensor (24), which may be a switch activated as the valve approaches its closed condition. <IMAGE>