【作者】 宋峥；

【导师】 卢泽生；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 随着科学技术的发展,精密和超精密加工技术占有越来越重要的地位,对于一些特殊材料和复杂形状的工件,很难采用传统的加工方法,使得特种加工技术获得了很大的发展,其中发展尤为迅速的是超声加工技术。超声技术出现在20世纪初期,是一门以物理、电子、机械及材料学为基础的、各行各业都会遇上的通用技术。近一个世纪的发展表明,超声技术在对提高产品质量,保障生产安全和设备安全运行,降低生产成本,提高生产效率等方面具有很大帮助。如今它已经渗透到国防建设、国民经济、人民生活和科学技术等各个领域。本文建立了超声振动切削系统。首先对超声振动系统的换能器进行了设计。换能器分为两种:磁滞换能器和压电换能器。在分析对比了两种换能器的优劣后,选择了夹心式压电超声换能器,并进行结构设计。为得到功率的最佳输出,本文还研究了超声换能器和超声发生器的电路匹配问题,先通过谐振匹配计算出匹配电感,将换能器回路由容性转化为纯阻性,这样减小了无功损耗,提高了能量传输效率;再通过阻抗匹配计算出变压器匝数比,把换能器的阻抗变换成最佳负载,使发生器对换能器的功率输出效率最高。本文又对超声振动系统的变幅杆进行了设计。变幅杆主要是用来放大位移振幅(或振速)的,它把能量集中到较小的面积上起到了聚能的作用。变幅杆有圆锥形、悬链形、指数形、阶梯形等形状,本文使用ANSYS仿真软件对不同形状变幅杆进行了分析,通过模态分析确定变幅杆的振动特性,即变幅杆的固有频率和振型,通过谐响应分析确定变幅杆在一定频率下的振幅放大倍数。在对比各变幅杆的谐振频率和放大倍数后,选择了大端为圆锥形小端为圆柱形的复合变幅杆,并对其结构进行了设计。本文最后在精密车床对铝试件进行了加超声振动和不加超声振动的车削实验,实验结果表明:工件表面粗糙度值在超声波振动切削加工条件下明显减小。更多还原

【Abstract】 With the development of the science and technology, precision and super-precision machining technologies have an important increasing position. For some workpieces of specific material and complex shape, it is difficult to use the conventional machining method, so non-traditional machining is developed rapidly. One of them is ultrasonic machining technology. It emerged in the 20’s century. Ultrasonic is a current technology which is based on physics, electronics, mechanics, materials science and other subjects. With the development of this technology in the last century, it is indicated that ultrasonic technology has provided an huge help to improve the quality of product, ensure the safety of manufacture and the equipment operational, reduce the costs of production, increase efficiency and so on. Now it is already entered into national defense and economy, science and technology, people’s life and other domains.In this thesis ultrasonic vibrating system is built up. Firstly, ultrasonic transducer is designed. It includes two types: magnetic hysteretic transducer and piezoelectric transducer. The sandwich piezoelectric transducer is selected after the capability of the two types transducer is analyzed, and then the structure of transducer is designed. To acquire the excellent export of power, the optimal matching condition between ultrasonic frequency generator and transducer has been given in this thesis. It is calculated matching inductance by resonance matching in order that the resistance circuit of transducer translated into capacitive. It reduced power wasting and proved transmission efficiency. Then the turns ratio of transformer is calculated assure that the impedance of transducer became the excellent load of ultrasonic generator. Ultimately ultrasonic generator export rated electric power to transducer. Secondly, ultrasonic amplitude amplifier pole is designed in this dissertation. The amplifier pole is used to magnify amplitude (or velocity) and focus power on the less area, which is called gather power function. The shapes of amplifier pole have taper pole, catenary pole, exponential pole, ladder pole and so on. The different shape poles are analyzed by finite element analysis software ANSYS. To obtain the vibration modal and the intrinsic frequency of transformer, modal更多还原