| 摘要 |
<p>A switching valve has a spool or plunger 3 slidable in a valve housing, for controlling the flow between high pressure and low pressure ports 27, 24 and optionally other ports 33. The plunger shuttles between end positions defined by stops 13, 14 which may be adjustable. The plunger is moved by fluid pressure, mechanically, or in any other way. A magnet 5 is provided, for example on the plunger, for holding the plunger firmly in one of its end positions by cooperating with a magnetisable plate 7. This renders the valve effectively bi-stable and eliminates the need for restoring springs. A spring may also be used at either end of the spool and in one end position the magnetic attraction force may be assisted by a magnetic repelling force. <IMAGE></p> |
