Research On Static & Dynamic Character And Experiment Of A High-pressure Integrated Component Of Valve-controlled Pneumatic Cylinder

The high-pressure integrated component of valve-controlled pneumatic cylinder is a very important component of an underwater launcher. As a four-way-three-position directional valve and a high-pressure cylinder integrated into one component, the structure of the control unit can be greatly predigested and the weight of the whole devices is likely to be cut down. Based on the structure characteristic of the high-pressure integrated component of valve-controlled pneumatic cylinder, its mathematics model is developed. Then the performance of this component is investigated through computer simulation and physical experiment. Firstly, mathematical descriptions of flow characteristic, response characteristics and kinematical characteristics of the high-pressure integrated component of valve-controlled pneumatic cylinder are developed based on the First Law of Thermodynamics, Continuity Equation and Momentum Equation. Influence factors on response characteristics of the high-pressure integrated component of valve-controlled pneumatic cylinder are emphatically analyzed through simulation study with MATLAB software, which provide a theory foundation for the development of the high-pressure integrated component of valve-controlled pneumatic cylinder. Secondly, software model of inner field of four-way-three-position directional valve is built up based on FLUENT software. The influences of some factors such as inlet area to inner flow characteristics are discussed. The distributions of inner field, such as temperature, pressure, density, are analyzed. Finally, the performance detecting software of the high-pressure integrated component of valve-controlled pneumatic cylinder is programmed based on Simulink tool, and a set of experimental system is developed. The experimental results show that the high-pressure integrated component of valve-controlled pneumatic cylinder has satisfactory sealing and responding performance. It can track pulse signal whose periods can be 60ms, that is to say, the piston of the high-pressure cylinder can reciprocate over 16 cycles per sec. When working-pressure is 5MPa, the static leakage of the component is 0.0043 m3/s, and dynamic leakage is 0.0119 m3/s. The results of theory analysis and experimental research show that the high-pressure integrated component of valve-controlled pneumatic cylinder is feasible and effective. The study is of engineering importance for predigesting the structure of control unit of the high-pressure valve-controlled pneumatic cylinder. It lays a good foundation for the further research on high-pressure pneumatic component.