Research on the dynamic and static characteristics of electro-hydraulic proportional direction valve with flow feedback

Considering the problems that in existing electro-hydraulic proportional control technology, the internal feedback valve has complex structure, difficulties in manufacture and low control accuracy. While the electronic closed-loop controlled valve is of high cost, so it is difficult to meet the needs of ordinary customers. Since they are not compatible in mechanical structures, it brings great inconvenience for enterprises to manufacture. The traditional principle is broken through, and the displacement flow feedback control principle is applied innovatively to the 3-position 4-way proportional direction valve that may operate under open loop condition. Based on this, electronic closed loop channel is applied. And the coupling between internal feedback and electronic closed loop is eliminated by feed forward controller. In the research, a complete mathematical model is established based on the structure and working principle of the new valve. And the dynamic model is simplified as a first order linear system for theoretical analysis with the help of reasonable hypothesis. Then the multi-domain model is set up in simulation platform-SimulationX. Research on the dynamic and static characteristics of the valve working respectively in internal feedback and electronic closed-loop control model is involved. By digital simulation the key geometric parameters are calculate, and the valve prototype is manufactured. The basic properties are tested on a testbed. Experimental findings validate the correctness of the simulation results. It shows that the new valve is of good static and dynamic characteristics. © 2014 Journal of Mechanical Engineering.