【作者】 李江；

【导师】 刘贤喜；

【作者基本信息】 山东农业大学 ， 机械设计及理论， 2018， 硕士

【摘要】 随着我国丘陵山地农业的发展,丘陵山地拖拉机在我国山区耕作、运输领域得到了广泛的应用。由于丘陵山地普遍存在路况条件差、坡度大、地块小等问题以及我国对丘陵山地拖拉机研究还处于初级阶段,因此在丘陵山地作业的拖拉机经常会出现操作困难、稳定性差和安全性差等一系列问题,特别是丘陵山地拖拉机作业时的车轮打滑问题更是严重影响了作业效率。本文依托国家十三五重点研发项目—丘陵山地拖拉机关键技术研究与整机开发,以四轮驱动丘陵山地拖拉机为研究对象,针对拖拉机作业时因附着面摩擦系数太小而出现车轮打滑的现象,提出了一种新型的驱动力主动分配方案,设计一种新型的驱动力主动分配装置以实现驱动力高效分配,提高驱动性能。本文主要内容如下:(1)通过研究国内外丘陵山地拖拉机传动特性以及驱动防滑技术现状,学习了国内外研究成果,分析了不足之处。结合我国特别的丘陵山地作业工况,提出了丘陵山地四轮驱动拖拉机的驱动力主动分配系统。(2)对丘陵山地四驱拖拉机进行动力学的分析,在对拖拉机发动机、分动器以及驱动轮数学建模基础上对拖拉机的驱动效率进行分析,获得驱动性能最佳时的滑转条件。(3)根据丘陵山地四驱拖拉后桥结构特点和力学性能,通过SolidWorks对丘陵山地四驱拖拉机的后桥边减速器进行参数化设计,并设计了一种新型的驱动力分配装置以实现驱动力及时高效的分配。(4)对驱动力主动分配系统控制策略与控制算法进行研究,提出了一种模糊自适应PID控制算法对驱动力主动分配系统进行及时的调控。(5)运用ANSYS Workbench和Simulink分别对丘陵山地四驱拖拉机驱动力主动分配系统的机械关键部件和控制策略进行了仿真分析,结果表明零件强度符合设计条件,同时该装置可有效的抑制驱动轮的过度滑转从而改善打滑问题,提高驱动性能。更多还原

【Abstract】 With the development of agriculture in hilly areas in China,hilly mountain tractors have been widely used in the cultivation and transportation of mountainous areas in C hina.Because hilly mountainous areas generally have poor road conditions,large gradients,small plots,etc.,and Chinese research on hilly mountain tractors is in its infancy,tractors in hilly and mountainous terrain often have problems such as difficulty in operation,poor stability,and poor safety.It is the problem of wheel slippage during the operation of tractors in hilly mountains that seriously affects the operating efficiency.This article relies on national key development projects in the thirteenth five-year-hilly mountain tractor key technology research and machine development,four-wheel drive hilly mountain tractor as the object of study,for four-wheel drive tractor operation because of the friction coefficient of the adhesion surface is too small and the wheel slipping Phenomenon,a new type of driving force active distribution scheme is proposed,and a new type of driving force active distribution device is designed to realize efficient distribution of driving force and improve driving performance.The main content of this article fol ows:(1)Through the introduction of domestic and foreign tractor transmission characteristics and the status of driving anti-skid technology,summed up the domestic research results,analyzed the inadequacies;combined with China’s special mountain hill operating conditions,proposed the driving force of the hilly mountain four-wheel drive tractor initiative Distribution system.(2)Analyze the dynamics of hill-mount four-wheel drive tractors,and analyze the driving efficiency of the tractor based on the mathematical model of the tractor engine,transfer case and drive wheels,and obtain the slip conditions when the drive performance is optimal.(3)Based on the structural characteristics and mechanical properties of the four-wheel-drive rear axle of the hilly mountainous region,the rear axle reducer of the hill-drive four-wheel tractor was parametrically designed through SolidWorks,and a new type of driving force distribution device was designed to achieve timely and efficient driving force distribution.(4)Study the control strategy and control algorithm of the active distribution system of the driving force,and propose a fuzzy PID adaptive control algorithm to control the active driving force distribution system in time.(5)ANSYS Workbench and Simulink were used to simulate and analyze the mechanical key components and control strategies of the four-wheel drive tractor active distribution system in hilly mountains.The results show that the strength of the parts meets the design conditions,and the device can effectively suppress excessive slipping of the drive wheels.This will improve the slippage problem and improve drive performance.更多还原