Characteristics Research On Cartridge Electro-Hydraulic Proportional Flow Valve

With the rapid development of electro-hydraulic proportional control technology, electro-hydraulic proportional flow valves are more widely used in industrial production, which are core components in electro-hydraulic proportional control. Based on the above reasons, electro-hydraulic proportional flow valves is not only required for excellent control accuracy and dynamic response characteristics, but requied for reducing the technical complexity, manufacturing difficulties and cost as far as possible.On the basis of studying the function, types and the research situation of proportion flow valves, the cartridged electrical closed-loop proportion throttle valve firstly is designed as the existing electric closed-loop valve cannot work in the open loop. Then the author introduces working principle and structure of the valve, establishs the model of valve and does simulation analysis by SimulationX simulation software to study the static and dynamic characteristics of the valve and confirme the valve's major structural parameters. Simulation results show that the valve has not only simple structure, but also has improved the control accuracy and the dynamic response characteristics to improve the reliability of system. At the same time, it is an economic and reasonable selection in the situation of little change in load.The existing differential pressure compensate proportional speed-regulating valves are used to compensate differential pressure of main valves, whose structures are complicated and are influenced greatly by fluid power, meanwhiles the compensation effect is poor. Flow feedback proportional speed-regulating valves have better compensation effect, but their sizes are big, structures are complicated, and cost is too much. In view of the these shortages, the author design a cartridge pressure compensate proportional speed-regulating valves based on flow amplification characteristics of Valvistor hydraulic cartridge valves i.e., a linear relationship between the main valve's flow and the pilot valve's flow. A pilot operated pressure reducing valve that is installed between main valve and pilot valve compensate differential pressure of pilot valve mouth port, thus controlling the main valve's flow by input signal and the magnification can be easily adjusted. As a result of normally closed structure to eliminate the traditional pressure compensated proportional flow control valve inherent impact and overshoot. Structure is more reasonable and more simple, and effective compensation, such as access to good flow characteristics.