PDF《学士学位毕业论文》

学士学位毕业论文 用于表征共振微悬臂的可精密调压 真空系统的设计 作者姓名: 李国良 指导教师: 李建昌 单位名称: 机械工程与自动化 专业名称: 过程装备与控制工程 东北大学2009 年6月Vacuum system with precisely adjustable pressure for resonant micro-cantilevers characterization By Li Guoliang Supervisor: Li Jianchang Department: Mechanical engineering and automation Major: Process equipment and engineering Northeastern University June

2009 ―I― 毕业设计(论文)任务书 毕业设计(论文)题目: 用于表征共振微悬臂的可精密调压真空系统的设计 设计(论文)的基本内容: 1)工程图纸折合 A0 幅面

4 张;

(包括装配图

2 张,真空室部件图若干张,零件 图) ;

2)设计说明书一份;

(包括文献综述、泵组的选择、各结构确定及参数计算、实 验中振动问题的解决,真空焊接等) ;

3)外文资料译文一篇.

(Characterization system for resonant micro- and nanocantilevers, Rasmus Sandberg, Anja Boisen, and Winnie Svendsen.). 毕业设计(论文)专题部分: 题目:精密可调真空漏气阀的设计 设计或论文专题的基本内容: 1)流导计算;

2)调节的范围计算. 学生接受毕业设计(论文)题目日期 第1周指导教师签字:

2008 年3月5日东北大学毕业设计(论文) 摘要i用于表征共振微悬臂的可精密调压 真空系统的设计 摘要微悬臂梁是一种高灵敏度的纳米传感元件. 由于在测量和检测探头方面成本低并且 具有较高的灵敏度,微悬臂梁的研究和应用范围不断扩展.表征微悬臂梁的实现基于超 高真空系统.该系统的真空度可达到1*10 -6 Pa.因为振动对微悬臂的实验测定有很大影 响,所以设计了减振支架和泵座,且用波纹管连接真空室和分子泵,从而有效地阻止振 动传入真空室. 本设计主要实现对真空室气体压力的精确控制.目前,微流体控制技术主要有2个 研究方向:微流量泵和微流量控制阀.本文所研究的是微流量控制阀,当要求调节的真 空度小于10-3 Pa时,该阀通过一套精密的杠杆螺旋机构来进行调节的;

当要求调节的真 空度大于10-3 Pa时,采用压电陶瓷作为微驱动控制器来控制微流量控制阀的阀芯开口, 从而实现微流量的精密控制. 本课题研究的内容包括: 1.通过计算设计一个表征微型纳米悬臂传感器共振特性的真空系统,并对真空室采 取一定的减振措施. 2.通过设计精密可调漏气阀来达到精确调节真空室内的压力的目的. 3.漏气阀中应用压电陶瓷来驱动,分析压电陶瓷驱动器电压的变化与真空室压力变 化的关系,建立压电陶瓷驱动器的输入电压与真空室压强之间的关系式. 4.真空系统中的焊接技术. 关键词:微悬臂,漏气阀,压电陶瓷,精密可调,真空焊接 东北大学毕业设计 (论文) Abstract ii Vaccum system with precisely adjustable pressure for resonant micro-cantilevers characterization Abstract Micro-cantilever is a high sensitivity nano-sensor. The measuring objects and the range of applications of micro-cantilever are increasing due to the low cost and high sensitivity as measurement and detection probes. The characterization of the micro-cantilever is constructed in an ultra-high vacuum system ,which has a vacuum degree of 1*10-6 Pa . The vibration has a great influence on the experimental determination of micro-cantilever, so a damping support and a pump seat are designed, with bellows connecting the vacuum chamber and the molecular pump to effectively prevent the vibrations into the vacuum chamber. The precise control of gas pressure is one of the important parts in my design. At present, micro-fluid control technology mainly includes two research directions: micro-flow pump and micro-flow control valve. Micro-flow control valve is studied in this paper. When requested to adjust a vacuum degree below 10-3 Pa , use a lever-and-screw mechanism to achieve precise adjustment .When the requested vacuum degree over 10-3 Pa, use the piezoelectric ceramic as a micro-drive controller to control the openings of micro-flow control valve spool to achieve precise control of micro-flow. The main research topics include: 1. Design a vacuum system for characterization of the resonant properties of micro- and nanocantilever sensors by calculating. Take some measures to prevent vibration. 2. Design a variable leak valve to achieve precise control of the gas pressure. 3. Drive variable leak valve using the piezoelectric ceramic. Analyze the changes between drive voltage of the piezoelectric ceramic and the pressure of the vacuum system. Establish the relationship between the input drive voltage and the pressure of the vacuum system. 4. The welding technology in the Vacuum system. Key words: micro-cantilevers;