Pneumatisches Stellglied mit Steuerventilsperrung durch permanenten Magnet.

摘要

A bistable electronically controlled pneumatically powered transducer for use, for example, as a valve mechanism actuator in an internal combustion engine is disclosed. The transducer has an armature (13) including a piston which is coupled to an engine valve, for example. The piston is powered by a pneumatic source and includes pneumatic damping with a one-way return of air compressed beyond source pressure back to the air source as it nears its destination position. Air supplied to power the piston may be differentially controlled to compensate for asymmetric resistance to movement and the air damping may be differentially controlled to provide dissimilar damping at the two extremes of piston motion. The armature is held in each of its extreme positions by pneumatic pressure under the control of control valves (15,17) which are in turn held in their closed positions by permanent magnet latching arrangements (21, 23) and are released therefrom to supply air to the piston to be pneumatically driven to the other extreme position by an electromagnetic arrangement (25,27) which temporarily neutralizes the permanent magnetic field of the latching arrangement (21,23).