Solenoid operated pressure control valve

TLDR: In this article, a solenoid actuated pressure control valve includes a central passage extending axially through the coil and an armature is movable axially within the passage, magnetically attracted to the pole piece when the coil is energized.

Abstract: A solenoid actuated pressure control valve includes a solenoid coil having a central passage extending axially through the coil. An armature is movable axially within the coil passage to be magnetically attracted to the pole piece when the coil is energized. Fluid pressure at a supply port of the valve biases the armature to its opposite end limit of movement when the coil is deenergized. Various forms of valving arrangements are disclosed, in one of which valve heads are located on the opposite ends of the armature to engage either of opposed valve seats dependent on whether the coil is energized or not. In other arrangements, the armature engages a push rod to unseat one valve upon energization of the coil while closing a seond valve. The one valve is biased to its closed position by supply port pressure when the coil is deenergized, the push rod opening the other valve. The valves operate to connect a control port to a sump port when the coil is deenergized and to connect the control port to the supply port upon energization of the coil. One form of valve employs a diaphragm to hydraulically isolate the coil, pole piece and armature from the controlled fluid.