机床结合部刚度和阻尼特性匹配设计方法

Machine tool structure is made of part components and their mutual connection joint surface. The surface is the weak link of machine tools, and it largely affects the machine tool performance. How to effectively use combined with damping characteristics of joint surface and reasonable distribute the stiffness of joint surface is the problem which is urgent need to resolve in the machine tool structure design. The project takes the typical bolt joint surface and rolling guide joint surface in CNC machine as examples, starts from the evolution mechanism of stiffness and damping in the joint surface, obtains a general foundation characteristic data of joint surface through experiment method , establishes physical properties model of evolution regularity of the joint surface stiffness and damping, and provides a theoretical basis for the rational matching design of joint surface stiffness and damping. Then it establishes the machine outline feature model considering the property of joint surface through boundary element method, finds out weak joint surface through the distributed calculation of elastic energy ,damping energy and inertial energy in machine tool, and realizes the reasonable distribution of the joint stiffness and damping based on the established joint stiffness damping characteristics evolution law, so as to explore a machine tool joint stiffness and damping characteristics in the whole system of the allocation mechanism, to achieve the goal to improve machine tool performance. This project provides a new method to solve rational design of machine joint surface in the documentation phase, has an important significance to improve the machine design, manufacturing and assembly process level.

机床结构是由零部件及其相互联接的结合面组成，结合面是机床中的薄弱环节，对机床整机性能影响非常大，如何有效利用结合面的阻尼特性、合理分配结合面刚度是目前机床结构设计中亟须解决的问题。本项目以数控机床中螺栓结合部和滚动导轨结合部为例，从基础结合面刚度和阻尼的形成与作用机理出发，通过实验获取具有通用性的结合面基础特性数据，建立全尺度结合部刚度和阻尼特性模型，从理论和实验角度研究结合部刚度与阻尼的演变规律。然后基于边界元法建立考虑结合部特性的机床整机动力学模型，从机床整机结构系统出发，通过整机系统弹性能、阻尼能和惯性能分布计算，识别薄弱结合部；基于所建立全尺度结合部刚度与阻尼特性模型，实现结合部刚度和阻尼的合理分配，提升机床整机性能。本项目从机床整机系统角度研究结合部刚度和阻尼特性的分配机制，为解决图纸设计阶段机床结合部合理设计提供了方法，对提升高档数控机床的设计、制造及装配工艺水平具有重要意义。

以数控机床结构中应用较多、且对机床整机性能影响大的螺栓结合部和滚动导轨结合部为主要研究对象，从理论和实验方面探索了机床结合部刚度和阻尼特性的作用机理及其合理匹配设计方法。.首先，完善了结合面基础特性实验方法与装置，发明并开发了一种静态加载与动态激振分离的结合面法向静动态基础特性实验测试装置，创建了系统化的可进行不同配对工况条件下的结合面静、动态基础特性数据实验测试系统，实现了结合部特性解析中对结合面基础特性数据的全面提供；建立了基于结合面基础特性数据的平面结合面特性的各向同性虚拟材料表征模型，实现了平面结合面接触特性的快速求解。.其次，建立了考虑螺栓头结合面、螺纹结合面、螺栓及法兰结合面的螺栓结合部特性解析模型，开发了相应的解析程序及其实验验证系统，揭示了螺栓预紧力、法兰厚度、螺栓规格之间的耦合关系，提出了单元螺栓结合部的四点和六点等效模型，为整机有限元分析中螺栓结合部建模提供了一种简化解决方案，解决了目前机床整机有限元解析中螺栓结合部精确计算与计算规模大的矛盾。.发明并开发了滚珠与滚道结合面接触特性测试实验装置及滚动导轨副全刚度实验测试方法与装置，建立了滚动导轨结合部全刚度解析模型，形成了从滚动体与滚道接触特性到滚动导轨副特性解析与实验测试的系统化方法与装置，不仅可以为机床整机特性预测分析提供滚动导轨结合部特性数据，而且可以为开展新型滚动导轨副主动设计与分析提供方法与实验设备；发明了一种自带油膜阻尼器的新型滚动导轨副结构，从往复振动特性出发推导了油膜切向和法向阻尼表达公式，发明并开发了油膜阻尼实验测试方法与装置，为该新型滚动导轨副的进一步开发奠定了理论基础； 建立了滚动导轨结合部刚度等效计算方法，解决了机床整机性能有限元分析中滚动导轨结合部建模复杂性与计算精度之间的矛盾。相关成果对工作母机整机特性分析、陀螺仪减振、新型滚滑复合导轨开发及滚动导轨设计与工艺分析具有广阔的应用前景。