非全周开口滑阀稳态液动力研究

非全周开口滑阀是液压阀的基本结构形式之一,其阀口是在阀芯凸肩圆周上均布若干不同形状的节流槽,用于获得不同流量控制特性。随着阀口开度变化,阀口节流面的位置、形状和射流角都会随之变化,因而传统理论计算方法无法准确计算压力流量、液动力特性等。采用计算流体动力学(CFD)方法,针对两种典型节流槽形式的滑阀进行了三维流场仿真分析研究,获得了不同流动方向下阀口全行程压力流量和液动力特性,并与试验测量结果进行了比较,两者吻合良好;分析比较了流场计算和理论公式计算结果。研究发现在特定的阀口开度范围内,液动力会使阀口趋于开大。此项研究对于非全周开口滑阀压力流量、液动力等性能预测以及减小阀驱动力具有重要意义。

STUDY ON STEADY FLOW FORCE OF NON-CIRCULAR OPEING SPOOL VALVE

The non-circular opening spool valve is one of basic construction of hydraulic valve, which places axisymmetrically several notches on the spool to form the restriction configuration. This type of valve is widely used in direction and velocity control for hydraulic actuators. Its restriction location, shape and flowing angle are shifted with the spool motion, and therefore it is difficult to achieve a reasonable prediction of the flow force by the traditional theoretic methods. The computational fluid dynamic method is used to investigate the three dimensional flowing fluid in a typical flow-direction control valve. The numerical result of the steady flow force and flow-pressure characteristics on the whole opening range agree well with the observed one. The results show that direction of steady flow force in the non-circular opening spool valve changes with the shift of the flow direction on the notch pass. A very useful guidance on the prediction of the steady flow force and other performances of non-circular opening spool valve is provided.