Abstract: In order to solve the problems of large leakage and large vortex area of some tractor multi‑way valves, a tractor multi‑way valve with U‑semi‑circular throttle groove is designed, and the dynamic characteristics of U‑semicircular throttle trough tractor multi‑way valve are studied through simulation experiments. The results showed that the outlet flow of U‑semicircular throttle valve showed the characteristics of slow first, then fast and then slow. The steady‑state flow rate of the outlet of the multi‑way valve was 113 L/min, the flow change was stable without shock, and  the control characteristics were good. The test scheme of U‑semicircular throttle groove tractor multi‑way valve was formulated, and it was concluded that the pressure difference at the valve port decreased with the increase of the displacement of the valve core, and the minimum pressure difference at the valve port was 1.2 MPa. The maximum leakage of the multi‑way valve was 10.5 mL/min, which met the leakage index. Therefore, it was verified that the flow change of the U‑semicircular throttle channel multi‑way valve was stable and the internal leakage was small.

Key words:  tractor；multi?way valve, U?semicircular throttling groove, dynamic characteristics, leakage

摘要： 为优化部分拖拉机多路阀流量特性、减小压差等问题，设计一种具有U-半圆形节流槽结构的拖拉机多路阀，通过仿真试验研究U-半圆形节流槽拖拉机多路阀的动态特性。结果表明：U-半圆形节流槽出口流量呈现先小后大再小的特点。多路阀出口稳态流量为113 L/min，流量变化稳定无冲击，控制特性好。制定U-半圆形节流槽拖拉机多路阀试验方案，通过试验得出阀口压差随着阀芯位移的增大而减小，阀口最小压差为1.2 MPa；测得多路阀最大泄漏量为10.5 mL/min，满足泄漏指标。从而验证U-半圆形节流槽多路阀流量变化稳定，内泄漏量小。

关键词: 拖拉机, 多路阀, U-半圆形节流槽, 动态特性, 泄漏量