【作者】 秦贞沛；

【导师】 朱俊平；

【作者基本信息】 西北农林科技大学 ， 机械设计及理论， 2011， 硕士

【摘要】 当今激烈的市场竞争要求企业必须对市场的需求快速的做出响应,而传统的产品开发过程开发周期长、成本高、缺乏竞争力,在工程机械的新产品开发中面临着同样的问题,而虚拟样机技术的成熟和在产品开发中的应用为研究人员提供了强有力的工具和手段。本文探讨了将虚拟样机技术应用于液压挖掘机工作装置设计中,主要从以下几方面进行了研究:介绍了虚拟样机技术及其应用,通过对比传统产品的开发过程与应用虚拟样机技术产品的开发过程阐述了虚拟样机技术应用在液压挖掘机设计上的必要性。介绍了挖掘机工作装置的组成,对工作装置自由度进行了计算,计算出挖掘机工作装置自由度数目为零,即工作装置具有确定的运动轨迹。在三维建模软件Pro/E中建立了挖掘机工作装置各构件的三维模型并进行装配得到了挖掘机工作装置的三维实体模型。将在Pro/E中建立的三维模型导入到ADAMS中,对各构件重新定义,建立工作装置虚拟样机。进行运动学分析,确定了挖掘机工作装置的运动范围,得到了挖掘机的一些特殊工作尺寸,铲斗齿尖和铲斗背部运动不会产生干涉。在远、中、近三个挖掘位置进行动力学仿真,得到挖掘机工作装置各铰接点在工作过程中力和力矩的变化曲线,为进一步进行优化和有限元分析提供了分析载荷;三次仿真相比较表明,随着挖掘位置靠近挖掘机停放位置动臂液压缸最大作用力变小、斗杆液压缸最大作用力先减小后变大、铲斗液压缸最大作用力变大,但是变化范围不是很大,挖掘厚度减小、挖掘半径减小;在同一挖掘位置两种挖掘方式的仿真表明,斗杆挖掘所占权重越大液压缸受力越大,斗杆挖掘可以获得更大的挖掘半径和挖掘深度。论文将工作装置关键铰接点的坐标值参数化,进行设计研究和优化分析。通过设计研究可以得到了单个设计变量对样机性能的影响和灵敏度。通过优化分析,液压缸的作用力明显减小,动臂液压缸最大作用力由优化前的13.30KN降到12.992KN,斗杆液压缸最大作用力由优化前的4.86KN降到4.729KN,铲斗液压缸最大作用力由优化前的3.83KN降到3.655KN。利用仿真技术建立液压元件和液压系统的仿真模型。首先将液压元件的物理模型转化为数学模型,在Simulink中建立了液压元件的仿真模型并对模型进行了封装。在完成液压元件模型建立的基础上,将液压元件连接起来建立了液压回路的仿真模型,完成机电液一体化联合仿真准备工作。更多还原

【Abstract】 Today’s fierce market competition demand business respond quickly,but the traditional product development process need long development cycles and high costs.The engineering machinery in new product development was facing the same problem,the virtual prototype technology matures and the application of the product development provided a powerful tool and means for researchers. This paper discussed the way to use the virtual prototype technology in hydraulic excavator design, the studied mainly included the following aspects:First we introduced applications of virtual prototyping technology,comparing the traditional product development process with the application of virtual prototyping technology,which showed virtual prototyping technology is very important in hydraulic excavator design.This papers brief introduced the composition of the excavator and calculated the freedom of working device,the number of degrees of freedom was zero,which determined the working device is correct. This papers created three-dimensional model of each component and assembled excavator three-dimensional solid model in the three-dimensional modeling software PRO / E,three-dimensional model would be imported into ADAMS.Re-definited various components which was created in PRO / E so as to establish a working prototype device. We got the work scope of excavator and some special data through simulation the system in ADAMS/View,which showed movement would not produce interference in working device. Furthermore, We got the curves of hinge point force and torque by dynamic simulation, which was the base for optimization and finite element analysis. Comparing three simulation we could find that with mining location close to the excavator the biggest boom cylinder force get smaller, the biggest stick cylinder force decrease and then become larger, the biggest bucket cylinder force become larger, but the change range is not great, mining thickness decrease, mining radius decrease. In the same mining position of two mining simulation showed that stick mining need bigger force, stick mining need bigger force can get bigger mining radius.This papers would paramrtric the key hinge point coordinate of working device in order to design study and optimization analysis. Over design study obtained effect of a single design variables and sensitivity. optimization analysis significantly reduced the force of hydraulic cylinder, the biggest boom cylinder force reduced to 12.992KN from 13.30 KN, the biggest stick cylinder force reduced to 4.729KN from 4.86KN, he biggest bucket cylinder force reduced to 3.655KN from 3.83KN.Using simulation technology to build hydraulic components and hydraulic system simulation model. First changed the physical model of the hydraulic components into a mathematical model, then packaged hydraulic components model which was created in Simulink. On the basis of that connected hydraulic components together to establish a hydraulic circuit simulation model.更多还原