Patent ID: 8823390
Filing Date: 2014-09-02
Classification: F16K

Abstract:
1. A method for monitoring operation of a solenoid valve having an armature and a poppet coupled to the armature and disposed on a valve seat, wherein the armature is movable between an open position and a closed position, comprising: energizing a coil in the valve to generate sufficient magnetic force to move the armature and to generate a current signature reflecting current vs. time; detecting a first inflection point in the current signature, wherein the first inflection point occurs when the armature starts to move from one of the open and closed positions toward the other of the open and closed positions, and wherein the first inflection point corresponds to a decrease in a slope of the current signature; and detecting a second inflection point in the current signature, wherein the second inflection point occurs when the armature moves completely to the other of the open and closed positions; wherein the first inflection point and the second inflection point respectively reflect a time the valve begins to open and a time the valve is fully open, and wherein a time between the first inflection point and the second inflection point reflects a travel time of the armature during a single stroke from the closed position to the open position.