Electrohydraulic servo valve with proportional pressure control - achieved by mechanical return spring and spring-centred 4-3 way valve

摘要

The valve sets the desired value as an electrical quantity in the control solenoid exerting an appropriate force on the armature rod and, with this force, sliding the control piston against the mechanical return spring so that the control piston allows the control pressure medium to flow from a connection point to a second connection point and on into an operating chamber of the hydraulically operated, spring-centred 4/3 valve. The control piston then slides out of its middle or rest position and allows the pressure medium to flow from a third connection into a fourth or fifth connecting so that the throttle piston is moved out of its rest position.