大功率拖拉机悬浮式前桥悬架插装式比例阀建模与设计

悬浮式前桥作为大功率轮式拖拉机的关键零部件，对衰减因路面扰动激励而产生的振动有着重要作用，而插装式比例阀为悬浮式前桥系统的振动控制过程提供了重要保障。本文设计了用于前桥悬架系统的插装式比例阀液压系统回路，并对工作机理进行了分析，建立了非线性数学模型，明确了设计部件与悬架性能之间的内在关联，通过部件参数的设计优化，可实现多种模式的前桥悬架阻尼调节。为降低设计参数的不确定性及设计方案的重复性，采用田口设计方法，选择蓄能器状态、节流阀孔径等因素作为设计因子，以阶跃和正弦激励作为噪声因子，设计了6因子混合水平的田口实验方案，并对设计方案进行信噪比和均值的方差分析。结合AMEsim仿真模型对设计方案进行验证分析，得到基于悬架输出力、簧载质量振动加速度评价指标的最优配置设计，并对其设计方案进行动态特性分析。结果表明：当负载阶跃变化时，约2s内，液压油缸两腔压力可调整至平衡位置；当路面阶跃激励时，插装式比例阀可快速响应，调整时间小于0.5s，系统可达到稳定状态，满足大功率轮式拖拉机前桥悬架运输作业工况下的减振需求。

Modeling and Design of Cartridge Proportional Valve of Front Axle Suspension for High-power Wheeled Tractor

As a key component of a high-power wheeled tractor, the front axle suspension plays an important role in absorbing the vibration caused by random road excitation, and the plug-in proportional valve provides an important support for the vibration control of the front axle suspension system. For developing the design capability of exclusive agricultural machinery, a hydraulic system circuit of the plug-in proportional valve for the front axle suspension system was developed, and its structure mechanism was analyzed to construct the front axle suspension system that can be opened in time. On the basis of this situation, a nonlinear mathematical model was established to clarify the inherent relationship between design component and suspension performance. And then, various modes of front axle suspension with adjustment damping can be realized via the design optimization of the component parameters. In addition, in order to reduce the uncertainty of the design component parameters and the repeatability of the design schematic, Taguchi design method was introduced to implement and take the accumulator, throttle valve size, proportional valve as design factors. Step and sinusoidal excitation were regarded as noise factor. A 6-factor mixed level Taguchi experimental design schematic was developed. Subsequently, the variance analysis of the signal to noise ratio and mean value of each design scheme were derived. Combined with the AMEsim simulation model, the optimal design scheme was analyzed and verified on the basis of the evaluation indicator with suspension output force and sprung mass vibration acceleration, the sprung mass vibration acceleration can be reduced, which can effectively improve the driving comfort of the tractor. On the basis of the AMEsim simulation model, the dynamic property of the optimal design scheme was analyzed. When the load was changed, the pressure of the two chambers of the hydraulic cylinder can be adjusted to the equilibrium position with about 2s;when the road was excited by step, the plug-in proportional valve can respond quickly, the adjustment time was less than 0.5s, which can promote the ride comfort of the wheeled tractor, thereby enhancing the design capability and providing the reference for the design and development of the front axle suspension system for high-power wheeled tractor.