为了研究平地机工作装置的运动学特性,提出工作装置混联机构简化位置正解的分析方法.根据平地机工作装置结构及各部件运动副关系,抽象出工作装置机构模型.基于平地机作业方式特点,对该机构进行分解和分析,确定少自由度并联机构为该机构的主体.利用螺旋理论对该并联机构进行自由度分析,采用数值分析法对该并联机构进行位置正解分析,并基于ADAMS实现平地机工作装置并联机构部分的位置正解分析.现场的物理试验表明,对于工作装置并联机构部分的位置正解,试验结果与计算机仿真结果基本吻合,最大误差不超过3%,满足平地机工作装置的精度要求;从而验证了所提出的分析方法的有效性.依据该理论基础,通过进一步的分析,获得平地机混联机构工作装置的运动学特性,最后讨论该机构设计要点,为工作装置设计和优化奠定理论基础.
In order to understand the kinematics characteristics of the working device of a grader,a forward displacement analysis method is proposed to analyze the device's hybrid mechanism.A hybrid mechanism model of the grader's working device was extracted according to its structure and spatial kinematic pairs.The model was then decomposed and analyzed based on its working conditions,and features.A lower-mobility parallel mechanism was confirmed to be the main part of this hybrid mechanism.A forward solution of position for the mechanism was obtained based on a numerical analysis method,while degree of freedom analysis was conducted based on the screw theory,A forward displacement analysis on the working device's parallel mechanism was carried out using ADAMSTM,a system dynamic analysis software tool.Experiments were performed subsequently to validate the effectiveness of the proposed analysis method.The results showed that experiment data losely matched computer simulation data,with less than 3% maximum error.On the basis of this theoretical foundation,the kinematics characteristics of the working device hybrid mechanism were obtained.The key issues on the optimization and innovation design of this mechanism were discussed.