Characteristics of a Precise Pressure Control Valve for the Force Control system

Pressure control valves are principal components used for controlling hydraulic fluid pressure, and therefore important for force control system. The operation principle of this value is simple, that is, the control pressure is balanced with-the restorative force of a spring compressed by displacement. This paper concerns the characteristics of newly developed pressure control valve, designed to overcome drawbacks of conventional pressure control valves, that is; i) large drain volume, ii) poor noise immunity, reproducigility, and hysteresis, iii) narrow output control range and low resolution, iv) poor responsiveness. Test runs revealed the outstanding performance of the prototype offered by its structural and operational features; i) changing the spring enhances flexibility is the ratio of control pressure to displacement, ii) null drain is necessarily negligible and pressured hydraulic fluid consumption is as little as the compensation volume for the spool travel, iii) significant linearity and resolution, iv) output pressure is controllable down to nearly zero from supply pressure with a negligible degree of hysteresis, and v) enough response. The proposed pressure control valve can be used in force control servo systems instead of the ordinary pressure control, especially in fields where the capacity of power source is limited, such as for car brakes, and attitude control systems of aircrafts and space vehicles.departmental bulletin pape