中文摘要：

以液压挖掘机的工作区域为对象，针对工作机构尺寸变化对挖掘范围及作业性能指标的影响进行研究，依据性能要求逆向为工作机构尺寸优化设计提供方向策略。分别考虑挖掘作业中的斗杆挖掘和铲斗挖掘典型工况，利用开发的工作装置运动分析软件绘制了相应的挖掘轨迹的包络曲线。分析工作机构中动臂、斗杆、铲斗尺寸变化对整机挖掘作业性能指标的影响规律，同时对工作机构进行动力学分析，并优化复合挖掘力。结果表明：动臂尺寸增加时，最大挖掘深度、挖掘半径分别增幅达5．56％、13．31％，最大挖掘高度、卸载高度增幅分别达51．36％、53．87％。斗杆尺寸增加使其4种主要工作尺寸总体变化率在5％以内，增加幅度较低，其中挖掘高度的相对增幅率是下降的。铲斗尺寸增加，最大挖掘深度增幅最大为2．7％，且相对增幅变化率均匀；最大挖掘高度、挖掘半径总体变化率在1．3％左右，最大卸载高度呈下降趋势。优化后获得较大的挖掘力为532．16kN较斗杆挖掘和铲斗挖掘有较大的提升，并给出在主要工况下的挖掘路径。

英文摘要：

Based on the working area of the hydraulic excavator, the effect of the size change of the working mechanism on digging range and the working performance indices is studied. According to the performance requirements, the optimization design strategy of the working mechanism size is provided. Considering the typical conditions during the excavating operation such as arm digging and bucket digging, the corresponding excavating trajectory envelope curves are drawn by the working device motion analysis software. The size change influence of the boom, arm, and bucket of the working mechanism on the digging performance indices of the whole machine is analyzed. The dynamics analysis is carded out on the working mechanism, and the complex digging force is optimized. The results show that when the boom size increases, the maximum digging depth and the digging reach are increased by 5.56% and 13.31%, respectively, and the maximum cutting height and the dumping height are increased by 51.36% and 53.87%, respectively. When the arm size is increased, the overall change rate of the 4 main working dimensions is less than 5%, but the increase rate is relatively low, and the relative increase rate of the cutting height is decreased. As the bucket size is increased, the maximum digging depth is increased by 2.7% and the relative increase rate is homogeneous. The overall change rate of the maximum cutting height, digging reach are about 1.3%, moreover, the maximum dumping height is decreased. After optimization, the larger digging force is 532.16 kN, and compared with the arm digging and bucket digging has large improvement, and the path of the main working conditions is given.