开中位多路阀稳态液动力的控制方法

Control method of steady-state flow force in open center multi-way valve

为解决装载机在实际工作中开中位多路阀复位时的卡滞问题,通过AMESim与Fluent软件联合仿真,搭建了多路阀铲斗联液压系统,得出了滑阀复位过程中,中位卸荷口P-T的流量曲线;将流量曲线离散化并作为Fluent仿真的入口边界条件,分析了滑阀P-T口的流场特性和稳态液动力的变化.结果表明:引起滑阀复位卡滞的原因是滑阀液动力在阀口开度2.5 mm时大于复位弹簧力.针对这种情况,在阀杆上设置挡流凸台结构,并对凸台参数进行优化,在不影响滑阀压力流量特性的同时将射流引导至阀体壁面,使滑阀液动力降低了61.6%.

In order to solve the problem of spool clamping of bucket loader when the open center multiway valve is reset during the work of the loader, the joint simulation with softwares AMESim and Fluent was adopted to build up the fluid power system of the bucket with multi-way valve and get the flow curve of center unloading P-T port in reset process of spool valve. Then the flow curve of P-T port was discretized and taken as the boundary conditions for Fluent simulation to analyze the characteristics of the flow field and the change of steady-state flow force of spool valve. The result showed that the reason of spool clamping would be such that the steady-state flow force was higher than the force of reset spring when the valve opening size was 2. 5 mm. Aimed at this problem, a convex baffle was set on the stem of spool valve and its parameters were optimized. The baffle would guide the fluid jet on to the wall of the valve body and reduce 61. 6% of steady-state flow force in spool valve and at the same time, it would not influence the pressure vs flow characteristics of spool valve.