Magnetostrictively actuated valve

摘要

A valve for fail-safe return to its normally closed condition relies upon solenoid-driven elongation of a magnetostrictive core element, for opening displacement of a valve member, and also relies upon a continuously available, stiffly compliant preload of the valve member into its position of lock-up at valve closure. The currently preferred material of the core is Terfenol-D, which offers a strong elongation response to inductively coupled excitation. The elongation response is sufficient to serve the purposes of driving a poppet-valve member from closed to open position, with a relatively short time constant, as well as to permit a closed condition of the valve wherein the driving end of the core is effectively disconnected from the poppet-valve member, so that the prestressed stiff compliance can alone be operative on the poppet-valve member for fail-safe closure of the valve.