Due to the fire resistance and environmental compatibility, using water as the working fluid in hydraulic circuits is receiving an increasing attention by both manufactures and users.This hydraulic directional valve is developed.When new water hydraulic directional valve is designed and manufactured, this paper introduces a water hydraulic 2/2 directional valve and its principle.The valve is composed of a hydraulically operated seat valve and a magnetic 3/2 direction valve.Aimed at the serious leakage and impact generating easily in reversing suddenly, an improved structure of water space seal is changed to direct seal, compaction force between main valve spool and main valve pocket was logically designed and damper in pilot valve port is matched with sensitive cavity in main valve.From the view of flow control, the methods of cavitation resistance of the directional water hydraulic valve are investigated.The computational fluid dynamics approaches are applied to obtain static pressure distributions and cavitation images in the channel of the main stage of the valve with two kinds of structure.The results show that the method of optimized spout can effectively restrain cavitation.The work provides some useful reference for developing water hydraulic control valve with the lower noise and lower vibration.Meantime, the structural parameters are optimized on the basis of information obtained from simulation.Static test, dynamic test and life test are accomplished, and the results show that the water hydraulic directional valve possesses good property, its pressure loss is 1.1 MPa lower, switching time is shorter than 0.025 s, and its strike crest is 0.8 MPa lower.The valve possess fine dynamic performance with the characteristic rapidly action and lower implusion.
