Abstract: The object is the ratio of the crosssectional area of the throttle hole between the recovery valve and the compression valve, which is aimed to research the hydraulic shock absorber of a tractor suspension system. The purpose of the paper is to analyze the influence of the ratio of the crosssectional area on the vehicle vibration reduction performance. The Recurdyn dynamics simulation model and AMEsim model of hydraulic shock absorber were established,  and the two models are cosimulated,  which have 162 degrees of freedom. Under high and low speed conditions,  and equivalent damping coefficients,  the influence of three schemes (the ratio of the crosssectional area greater or less than 1) would be compared and analyzed. The results indicate that the ratio of the crosssectional area of throttle orifice of hydraulic shock absorber should be less than 1 for agricultural vehicles operating at low speed. The crosssectional area ratio of throttle orifices should be greater than 1,  under the condition of medium and high speed to get better comfort. The design principle would be applied to the selection of the crosssectional area ratio of the throttle hole of the hydraulic shock absorber of tractors and other vehicles.

Key words: tractor, hydraulic shock absorber, crosssectional area ratio of throttle orifice, cosimulation, AMEsim, combinatorial optimization

摘要： 以某型拖拉机悬架系统液压减振器为研究对象，分析其复原阀与压缩阀节流孔截面积比对整车减振性能的影响。建立162个自由度的拖拉机整车Recurdyn动力学仿真模型和液压减振器AMEsim模型，并将两者进行联合仿真，在高速和低速工况，对比分析等效阻尼系数相等条件下的节流孔截面积比大于、等于及小于1的3种方案对整车减振性能的影响。结果表明：为获得更好的整车舒适性，对于常在低速工况作业的农用车辆，液压减振器节流孔截面积比值适宜小于1；常在较高和高速工况行驶的车辆，节流孔截面积比值适宜大于1。该设计原则可应用于拖拉机和其他车辆液压减振器节流孔截面积比的选取。

关键词: 拖拉机, 液压减振器, 节流孔截面积比, 联合仿真, AMEsim, 组合优化