Research On Displacement-pressure Cushion Structure Of High-speed Pneumatic Cylinder

Pneumatic cylinders are common actuators in the industrial automation. In order to improve the production efficiency and reduce cost, high-speed becomes inevitable trend. The restriction reason for high-speed is the cushion problem at the end of stroke. The relief and needle valve cushion mechanism for cylinders, commonly used nowadays, have less ability to adapt to the change of working conditions. Thus, the goal of the paper is to design a cushion structure which possesses a wide range of adaptive capacity to the conditions.The paper researches uniform deceleration method on cylinders, and explains the principle of uniform deceleration cushion. By experimentation, the relationships between the pressure needed in cushion chamber and the cushion parameters are obtained to realize the uniform deceleration.Based on the cushion characteristics of uniform deceleration, the mathematical model is built, and the kinematics equations are corrected by referring to the ideal equations of hydraulic cylinder. The pressure of cushion chamber and the exhaust flow equation can be gained. According to it, the solution process of the important parameter named throttling area to characterize these two methods can be worked out.Because of the great interaction of GUI and SIMULINK in MATLAB platform, simulation software was designed. According to the software, the orifice area of cushion valve changing with displacement can be obtained.Based on the orifice area curve of cushion valve changing with displacement and the cushion principle of pressure feedback, the displacement-pressure method is designed and processed, then the structure is simulated by using the revised simulation software and the adaptive ability is tested. According to the simulation and experimental results, it verifies the structure possesses a better adaptive ability in certain conditions.