A high pressure electronic pneumatic pressure reducing valve, consisted of a two-position three-port pilot valve controlled by electromagnet and a piston type main valve, was proposed. The valve used a pressure sensor and a controller to constitute the closed-loop feedback. By consuming a little gas in the pilot valve, rapidity and stability of pressure regulation were preserved, the influences of pilot leakage on the valve and unexpected icing in pilot valve could be avoided. Then the characteristics were analyzed based on the structure and working principle of the valve, finally the simulation model including the vibration of gas supply pressure and load flow rate was built up with AMESim. Simulation results showed that steady pressure reduction could be achieved under the condition of gas supply pressure slowly reducing and load flow rate fluctuating in a big range. When gas supply pressure is 31. 5 Mpa, the output pressure could be steady in 1 ~ 30 Mpa without adjusting the controller parameters; the influences of machining errors on the valve were also simulated, the results showed that under-lap of pilot spool should be avoided to reduce gas consuming and 10 |j,m is a suitable choice for the height of annular clearance.%提出一种高压气动比例减压阀,该阀由比例电磁铁控制的二位三通型滑阀式先导阀和活塞提升式主阀组成,通过压力传感器和控制器构成闭环电反馈控制,最高工作压力为31.5 MPa.该阀虽然存在少量先导耗气,但保证了压力调整的快速性和稳定性,克服了先导泄漏对减压阀的影响,避免了先导阀意外结冰的发生.在介绍结构及工作原理的基础上分析了该减压阀的特点,利用AMESim建立了考虑气源压力和负载流量波动的仿真模型.仿真结果表明:该阀在气源压力缓慢下降且负载流量大范围波动的情况下能实现稳定的压力输出,在不改变控制参数的前提下,当气源压力为31.5 MPa时输出压力可在1～30 MPa范围内稳定;先导阀预开口形式对压力精度影响较小,但应避免正开口以减少气体浪费;先导阀环形间隙高度控制在10μm左右较为合适.
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