SOLENOID CONTROLLED SERVO VALVE

A servo valve controlled by a bistable solenoid valve and activated by the same fluid-liquid or gas-it controls the flow of. A disk is mounted on a differential piston that travels back and forth in the housing. A compression chamber at one end of the piston communicates with a fluid intake and, by way of a seat facing the disk, with a fluid outlet. The piston has an eccentric control bore extending through it. A control chamber at the other end of the piston communicates with the fluid outlet through a depressurization channel and with the compression chamber through the control bore. The solenoid valve has a chamber and seat and an armature that travels back and forth in a tube. The tube extends through a coil on the housing. A gasket is mounted on the end of the armature facing the solenoid valve's seat. The other end faces a head accommodated in the tube. A yoke surrounds both ends of the coil. The depressurization channel extends through the chamber and seat and can be closed off by the plug. The armature, head, and yoke are made of soft-magnetic material. The opening pulse magnetizes the head and attracts the armature, opening the solenoid valve. The closing pulse demagnetizes the head, and the armature drops under its own weight and closes the solenoid valve. The device can be operated at approximately 10 mWsec a cycle.