湿软水田土壤行驶工况下拖拉机振动特性研究

[目的]拖拉机在湿软水田土壤中行驶时的振动特性与在道路上行驶时明显不同，揭示两种不同行驶工况下振动特性的差异，对拖拉机减振方案设计和悬架系统参数优化具有重要的参考价值和实际意义。[方法]通过对湿软水田土壤阻尼分析，获取湿软水田土壤阻尼系数与轮胎阻尼系数间的关系，并建立了轮胎-湿软水田土壤系统模型、拖拉机整车振动模型以及振动特性理论计算模型，用理论分析的方法，以江苏常发集团CF700型拖拉机为研究对象，计算并比较拖拉机行驶在农村未覆盖土路（国标D级路面）和湿软水田土壤中的振动特性。[结果]与农村未覆盖土路（国标D级路面）行驶工况相比，拖拉机在湿软水田土壤中行驶时，机身垂向振动相对于前、后轮的位移传递率分别下降31.4%和23.5%，俯仰振动幅值分别下降29.5%和24.6%。当拖拉机以3~18 km？h-1速度在湿软水田土壤中行驶时，其机身垂向振动加速度和俯仰振动角加速度平均降低33.0%和32.6%，前、后轮动载荷平均降低34.0%和31.2%，座椅安装处垂向振动加速度平均降低32.9%。[结论]研究结果可以为水、旱田两用拖拉机减振系统设计与智能悬架控制提供理论依据。
[Objectives] Vibration characteristics of tractor driving in marshy paddy soil is distinct with driving on the road,reveals the difference between the vibration characteristics of the tractor when driving on the road and has important reference value and practical significance for the tractor reduce vibration design and suspension damping system parameter optimization. [Methods] According to measurement results and analysis of marshy paddy soil damping,the damping coefficient relationship between the tire and marshy paddy soil was obtained and a tire-marshy paddy soil system model,tractor vehicle vibration model and theoretical calculation model of the vibration characteristics were established. With the Jiangsu Changfa Group CF700 tractor as the object of the study and with the theoretical analysis method,the body vertical and pitching vibration displacement transfer rate relative to front wheel and rear wheel,the body vertical vibration acceleration and pitch vibration angular acceleration RMS(root mean square),front and rear wheel dynamic load RMS and the vertical vibration acceleration RMS and pitch angular vibration acceleration RMS of the seat-mounted were calculated and compared with the vibration characteristics of the tractor that driving in the rural dirt road(GB class D road) and marshy paddy soil. [Results] The compared results showed that when tractor was driven on the rural dirt road(GB class D road) and in the marshy paddy soil,the body vertical vibration displacement transfer rate relative to front wheel and rear wheel were downgraded 31.4% and 23.5%,and the body pitching vibration displacement transfer rate relative to front wheel and rear wheel were downgraded 29.5% and 24.6%. When the tractor was driven at 3-18 km？h-1 driving speed in marshy paddy soil,the body vertical vibration acceleration and pitch vibration angular acceleration RMS were reduced by an average of 33.0% and 32.6%,front and rear wheel dynamic load RMS was reduced by an average of 34.0% and 31.2%,and the vertical vibration acceleration RMS of the seat-mounted was reduced by