FLUID PRESSURE CONTROLLER

摘要

A fluid pressure controller having a housing including an input port, a discharge port and an output port, and a spool axially slidably mounted in the housing. First and second chambers are defined by both ends of the spool and the housing. Ring valve members are mounted on the spool at axial spacings to define oppositely oriented variable-size orifices for pressure increase and pressure reduction. They are adapted to separately control communications between the first chamber and the input port and between the first chamber and the discharge port depending upon the axial position of the spool and close both communications when in its closed position. Thus the pressure control phase can be freely changed over among pressure increase, pressure reduction and pressure hold.