Investigation of Cutting Characteristics of Micromilling and Development of Ultrasonic Micromilling System

：在注塑模具、多种汽车零部件和移动的信息设备的制造中，对使用微型端米尔斯铣刀的高切削性能提出了要求。本文研究了超声微铣削的切削特性，并研制了超声微铣削系统。在此基础上，阐明了直径为30μm和10μm的微立米尔斯铣刀在微铣削加工中切削精度与主轴动平衡的关系。提出了微铣削加工中获得有效切削精度的动平衡条件。在后一项研究中，作者新研制了一种超声波主轴系统，其主轴以20，000 min-1的速度旋转，以41 kHz的频率和2μm的振幅振动。进行了移动的信息终端用草的单道划痕试验和cBN立米尔斯铣刀对淬硬钢的微铣削试验。阐明了该超声微细铣削系统适用于注塑模及零件的加工。

：High cutting performance using micro-end mills has been demanded in the manufacture of injection molds, several automotive parts and mobile information equipment. In this study, the author investigated cutting characteristics of micromilling and developed an ultrasonic micromilling system. As a result of the former study, it was clarified that the relationship between cutting accuracy and dynamic balance of main spindle in micro-milling operation using micro-end mills with diameters of 30μｍand 10μm. Then, the author proposed the dynamic balance condition to obtain effective cutting accuracy in the micromilling. On the latter study, the author newly developed an ultrasonic spindle system, which has the main spindle rotated with a speed of 20,000min-1 and vibrated with a frequency of 41kHz and an amplitude of 2μm. Several cutting tests were experimented, such as single scratch tests of grass for the mobile information terminal and micromilling of hardened steel by using cBN end mills. Then, the author clarified that this ultrasonic micromilling system is advantaged to the manufacture offine injection mold and several parts.