抄録
Our development program fabricated a proportional control valve that exclusively uses water as its working fluid. The valve is equipped with a spool, and the spool is directly driven by a proportional solenoid that is modified for water use. Characteristics of the proportional solenoid are described first in this report while proving its performances similar to those of the conventional oil hydraulics.
Following, structural characteristics of the water hydraulic proportional control valve are discussed. Water, the valve's working fluid, is low in lubricity and viscosity; therefore, hydrostatic bearings that support the spool are installed in the valve. In addition, to stabilize movement of the spool, damping orifices are provided. Particularly, the hydrostatic bearing portion is designed such that it minimizes the total leakage including bearing flow while obtaining load carrying capacity. The constant flow from the hydrostatic bearings prevents water from decaying in the valve. Lastly, the paper introduces experimental results of cylinder positioning controlled by the developed water hydraulic proportional control valve to verify its satisfactory performances as a control valve.
