Research Of Characteristic On Cartridge Electro-hydraulic Proportional Throttle Valve

Hydraulic technology is widely used in the field of industrial automation. With the hydraulic system development in the direction of high pressure, high flow and high power, the requirements of electro-hydraulic proportional valve in dynamic-static performance and noise are increasing at the same time. Two-way proportional throttle valve uses commonly the pilot control structure in occasion of large flow. The traditional two stage proportional throttle valve usually uses internal feedback, such as displacement-force feedback and displacement-pilot flow feedback amplification principle. Because of low control accuracy and slow dynamic response, this kind of valve only are applied to occasion which needs low control accuracy. The main spool displacement-electric feedback has higher control accuracy and good dynamic performance. This valve mainly used in the closed-loop system. Existing closed-loop proportional throttle valve include only electrical feedback channel, not internal feedback. Once there is problem on the electronic detection and control circuit, the electrical closed-loop valve would lose the function of continuous control.The subject combines the displacement-pilot flow feedback principle and displacement-electrical feedback principle, which optimize the control characteristics and solve the problem that electronic closed-loop valve couldn’t controlled under the damaged displacement sensor. Valvistor valve is a new type of hydraulic cartridge valve with internal hydraulic feedback mechanism, achieving the control of continuous flow proportional.In this paper, based on the Valvistor cartridge valve and electrical closed-loop controller including feed-forward controller, design Valvistor NG16, NG25and NG63cartridge proportional throttle valves. The research results show that the valve has simple structure, higher control accuracy, good dynamic and static characteristics. The valves meet the design requirements. Main contents are as follows:1. Introduce the basic concept of the electro-hydraulic proportional valves and cartridge valves, development history and current research applications.2. Determine cartridge valve working principle and the way of control and structure. Build static and dynamic mathematical models, laying the theoretical foundation for the subsequent simulation analysis.3. Calculate the structure parameters of cartridge proportional throttle valve. According to the working principle of proportional throttle valve, build the3-D model using the Pro/E software, and build the simulation system model by the SimulationX software.4. Analyze the static and dynamic characteristics and some factors to see the impacts to valve performance, such as the area ratio, the feedback throttling slot area gradient, and stable-state flow force, under the open-loop and closed-loop conditions. The structural parameters of the throttle are determined by simulation. Verify Valvistor NG16、NG25and NG63cartridge proportional throttle can meet basically requirements on the proportional flow control.