Abstract: For the purpose of improving the Muti-valve’s commutation ability and reducing the valve’s flow forces during its opening, a hydraulic excavator valve structure design method is put forward in the condition of virtual load. First, the excavator virtual load model was established by the excavator dynamic performance test data, statistics were used to express the load’s periodic and random characteristics. Then, a 3D valve model with the boundary conditions of virtual load was proposed to solve the flow forces during the valve’s opening and the fluid structure interaction method was used. Finally, the flow force response characteristics of different valve spool structures were presented by the model. The results show that spool with U-groove of moderate equivalent valve orifice area can effectively reduce the flow force under series of virtual loads.

Key words: commutation ability, virtual load, flow force, fluid-structure interaction, spool design