There is a relatively complex flow state inside the high speed on-off valve, which often produces low pressure area and oil reflux in the high-speed opening and closing process of the spool, causing cavitation and vortex and other phenomena. These phenomena will affect the stability of the internal flow field of the plate valve and the flow characteristics of the high speed on-off valve. Aiming at the problems of small flow rate and instability of internal flow field, a new spool structure was designed. The flow field models of two-hole and three-hole plate spools with different openings were established, and software Ansys Workbench was chosen to mesh the model. The standard k-ε turbulence model was selected for numerical simulation using Fluent software. The pressure distribution and velocity distribution under the same pressure and different opening degree were obtained. The structure and parameters of the optimization model were also obtained. The stability analysis of flow field under different pressure was carried out. The results demonstrate that the three-hole spool has a similar flow field change with the two-hole spool, but it does not create a low pressure zone, and the three-hole spool can work stably at 2 MPa or less. This method improves the appearance of low pressure area and oil backflow in the process of high speed opening and closing of spool. The stability of flow field and the flow rate of high speed switch valve are improved. Finally, the products designed in this paper are compared with existing hydraulic valve products. The results show that the three-hole plate type high speed on-off valve designed in this paper maintains the stability of the internal flow field under the condition of 200 Hz and large opening degree, and realizes the increase of flow rate.

高速开关阀内部存在相对复杂的流动状态，通常在阀芯的高速开关过程中产生低压区和油回流，从而引起气蚀和涡旋等现象。这些现象将影响板式阀的内部流场的稳定性以及高速开关阀的流动特性。针对小流量和内部流场不稳定的问题，设计了一种新的阀芯结构。建立了具有不同开口的两孔和三孔板式阀芯的流场模型，并选择了Ansys Workbench软件对该模型进行网格划分。标准k - ε使用Fluent软件选择湍流模型进行数值模拟。得到了相同压力，不同开度下的压力分布和速度分布。还获得了优化模型的结构和参数。进行了不同压力下流场的稳定性分析。结果表明，三孔阀芯具有与两孔阀芯相似的流场变化，但不会产生低压区，并且三孔阀芯可以在2 MPa或更低的压力下稳定工作。该方法改善了阀芯高速开合过程中低压区的出现和油的回流。提高了流场的稳定性和高速切换阀的流量。最后，将本文设计的产品与现有的液压阀产品进行比较。结果表明，本文设计的三孔板式高速开关阀在200 Hz，大开度条件下保持内部流场的稳定性，实现了流量的增加。