Electrohydraulic position regulator with two-stage proportional valve - has pilot electrohydraulic stage used to drive main fluid power stage with both having displacement sensors

摘要

A high performance linear servo hydraulic actuator (14) of a type suitable for use on a CNC controlled (10) machine, has fluid supplied by a proportional valve (17). The position of the piston of the actuator is monitored by a displacement sensor (24) coupled to an electronic unit. The valve has a closed centre design with the differential condition provided by displacing a spool using the control action of the proportional solenoids. The valve has a pilot stage (45) with the electromagnetic drive stages. This delivers outputs to displace the hydraulically controlled power stage delivering flow to the actuator. This stage is spring centred. Both pilot and main stages have linear displacement sensors. USE/ADVANTAGE - Provides precise position regulation. High speed, low power drain.