Ventil mit dynamischer Funktionsprüfung

摘要

A valve is provided with a means for determining the operability of the valve without causing it to change fluid conduction state. A spool member is axially moveable within a valve housing in response to pressure changes caused by the plunger of a pilot valve. The plunger is moved in response to an electromagnetic field induced by a solenoid coil. The coil is sequentially actuated at ever increasing intervals of time while the movement of the spool member is monitored by observing an output from a magnetically sensitive device which can be affected by the presence of a permanent magnet within its zone of detection. The permanent magnet is attached for movement with the spool member and the magnetically sensitive device, such as a Hall effect element, is attached to a stationary portion of the valve at a predetermined location. When the interval of deactuation of the coil is sufficient to cause the spool member to move the permanent magnet into the zone of detection of the magnetically sensitive device, a signal is provided and the valve is determined to sufficiently move the spool member to indicate its operability. None of the actions described immediately above result in a change in fluid conduction state of the valve.