【作者】 胡涛；

【导师】 谢大纲；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 气囊抛光工艺方法是20世纪90年代伦敦光学实验室提出来的一种新的抛光方法。较传统的抛光技术而言,气囊式小工具抛光技术是一种实用、经济、高精度的抛光技术。现有的抛光机床都是传统型机床,而并联机构无论是从结构上还是功能实现上都是一种新型机构。并联机构具有精度高、刚度大、惯性小、承载能力高、运动反解模型简单、操作速度高、易于控制等特点。本文从气囊抛光方法出发,以3-PRS型并联机构为原型,对如何用并联机构来实现光学元件的气囊抛光进行了研究并对并联抛光机床的主要部分进行了结构设计。3-PRS型并联机构为三自由度,其动平台在运动过程中除了绕中心的转动与Z方向上的移动以外,在X和Y向上还有偏移。以欧拉角和Z轴坐标就可以确定动平台的位姿,所以X和Y向上的偏移量与欧拉角是耦合的,经过计算得出了这两个方向上的偏移量与欧拉角的函数关系。对并联机构进行了静力分析。改变连杆长度与定平台半径长度来观察连杆的受力情况,根据连杆的受力情况选择了一组比较理想的定平台与连杆尺寸组合。用一种简洁的方法推导了该机构的正解和逆解。在Pro/E中建立了机构的三维模型,并将其导入到ADAMS中仿真验证了机构的自由度,分析了机构的输入与输出之间的运动特性,重点验证了机构的位置正反解算法的正确性以及动平台与连杆的干涉情况。对机床的主要部分进行了结构设计并利用Pro/E中的有限元分析模块进行了机床的静刚度分析和模态分析。通过分析确定了机床受力的薄弱环节,研究了机床模态分析的各阶振型及其振动特性。本文通过上述理论研究和分析,得出了一些初步的结论,为后续的研究工作奠定了基础,为该并联机床的设计与制造提供了理论依据。更多还原

【Abstract】 Bonnet tool polishing is a new polishing method which was put forward by London optical laboratory in the 1990s. Comparing with the traditional polishing technology, Bonnet tool polishing is a practical, economic, precision polishing technology. The existing polishing machine tools are Traditional machine. But parallel mechanism is a new kind of organization no matter from its structure or its function. Parallel mechanism has high precision and stiffness, small inertia, high bearing capacity, the solution model is simple. It can operation in high speed and easy to control. From the method of Bonnet tool polishing, Take the 3 - PRS type parallel mechanism for prototype, have studied how to use parallel mechanism to realize Bonnet tool polishing and have designed the structure of the main part of the parallel polishing machine.3 - PRS type parallel mechanism has three degrees. In the process of moving ,except the platform turning around the center and moving in Z direction, It also has some displacement in the X and Y direction. Euler Angle and Z axis coordinate can determine the pose of the moving platform. So the displacement in the X and Y direction are coupling with Euler Angles. Through calculation, I get the function between the displacement in the X and Y direction and Euler Angles. I did static analysis about the parallel mechanism. Change the connecting rod length and the radius of the fixed platform to study the force of the rod. According to the force of the connecting rod I chose an ideal group of size of the platform and the connecting rod. With a simple method I deduced the positive solution and the reverse solution of the parallel mechanism.Established 3d model of the mechanism in Pro/E and interface it into ADAMS to simulation. Through this method, I verified the freedom degrees of the mechanism and studied the motion characteristics between input and output. The most important is that it verified the correctness of the positive solution and the reverse solution of the parallel mechanism and the interference between moving platform and the connecting rod. I did the structure design of the main part of the parallel machine and its static stiffness analysis and model analysis with finite element mechanical module of the Pro/E. Through the analysis, determine the weak link of the machine, studied the vibration characteristics of the machine.Based on the theoretical study and analysis, get some preliminary conclusions and laid a foundation for the subsequent research work, provides theoretical basis for the design and manufacture of parallel machine tool.更多还原