【作者】 孙文才；

【导师】 罗建伟；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2010， 硕士

【摘要】 方滑枕结构广泛应用在数控铣镗机床中,是完成加工的主要部件之一,也是直接承受载荷的部件。方滑枕的静动态特性直接影响整个机床的精度、加工性能和产品质量。此外其变形问题也是国内外生产移动式方滑枕数控机床厂家所必须面对的主要难题,因而对方滑枕现有的结构行研究分析,以改进与优化它的结构和提高整个机床的精度具有十分重要的现实意义和经济效益。本文以TK6920重型数控落地铣镗机床方滑枕为研究对象,利用有限元软件ANSYS作为分析工具,对其结构进行分析和优化。主要的研究内容如下:运用三维软件建立了重型数控落地铣镗机床方滑枕、铣轴和镗轴的三维模型。根据机床的实际工作情况对方滑枕的受力和边界约束条件等进行了分析计算,确定了本文计算铣削力载荷的计算公式。分析了方滑枕变形的主要原因;采用有限元软件建立了方滑枕结构的有限元模型,并对方滑枕进行了有限元静动态分析。静态分析得到了方滑枕在自重下和载荷力作用下方滑枕不同伸出量时的变形量,建立了方滑枕伸出量与变形量、方滑枕伸出部分质心变化量与变形量的数学函数关系;分析了方滑枕一定伸出长度时的变形量与刀盘直径的关系和变形量与转速的关系。模态分析得到了方滑枕的固有频率;瞬态分析得到了瞬态载荷作用下方滑枕的动态特性,并建立了变形量与时间的关系曲线。通过有限元静动态分析,得知方滑枕结构的静动态特性满足加工的条件要求,其强度安全系数较大,结构比较臃肿,具有一定的优化空间。将有限元方法和优化技术相结合,采用选型优化方法对方滑枕结构进行了以减重为目标以静态参数为约束的优化设计。阐述了方滑枕常用的变形补偿方法和原理,通过对方滑枕进行补偿,可以减小方滑枕的变形和满足机床加工的精度要求。分析了方滑枕挠度变形补偿方法,建立了拉杆拉力与方滑枕伸出量的关系曲线。更多还原

【Abstract】 The structure of the square ram is widely used in NC boring and milling machine. It is one of major parts of completing processing and it is the part that directly receives loads. The static and dynamic properties of square ram influence the precision and processability of the whole machine tool and products’quality directly. Besides, the deformation of square ram is also a difficult problem that manufacturers of NC machine with movable type square ram must face to. So the research and analysis of the structure of square ram is very important realistic function and economic function to improve the NC machine’s precision and original structure and structural optimization design. The TK6920 NC Boring and Milling machine square ram is research object. The square ram is researched with general finite analysis software ANSYS. The main work is as follows:The NC boring and milling machine’s square ram and milling spindle and boring spindle solid models have been built through 3 dimension software. It analyses and calculates the loads and boundary constraint condition of square ram based on the actual working environment and adopts the milling forces calculation formula of the paper.The paper analyses the main causes of square ram’s deformation. The finite element models of square ram has been proposed based on the finite element software. The static and dynamic analysis of square ram have been computed. The results of static analysis show displacement of different extended length of square ram with ram-self weight or loads. The mathematical models for deformation and extended length and axial gravity variation of extended length’s ram and deformation are established. It analyses relationship about deformation and cutter diameter and deformation and rotate speed when square ram extends fixed length. The modal analysis has been performed and shows the square ram natural frequency and mode shape. The results of transient analysis show dynamic properties of square ram with transient forces and relationship about deformation and time with transient loads.According to results of the static and dynamic analysis, the static and dynamic properties of square ram meet the requirements of machining. Its intensity safety factor is high and it’s with optimal space for bloated structure. With combination of finite element analysis and optimization design, reducing the square ram’s weight as the optimum design and static parameters as constraint conditions, its structure is designed with type-selection optimization design method.It introduces general compensation methods of square ram. They can reduce deformation and meet the precision of NC machine. It analyses the deflection ram. compensation of square ram and establishes a curve of pull rod and extended length’s更多还原