Development of a new mirror finishing process for the inner surface of capillary tube of 50〜100 micrometers in diameter by the application of magnetic field assisted machining

毛细管用于微型机械和微型医疗机械等。然而，目前还没有一种加工技术能够加工出高达0.3μm Rz的内表面粗糙度。在本研究中，我们致力于将磁性研磨技术应用于微米级管材的精密内精加工技术中。研究结果如下：1.微米管内磁场辅助光整加工的实验装置、磁体刀具的制作和光整加工实验通过永磁体与直径0.1 mm的钢琴钢丝工具之间的磁力作用于微米管内表面。我们制作了一套实验装置，通过调节磁铁与微米管表面的距离来控制作用在钢琴钢丝工具上的加工力。在本研究中，假设管子的曲率半径为无穷大，利用平面模型进行了试验。研究了微米管的光整加工特性，表面粗糙度从0.14μm Rz提高到0.09μm Rz。2.研制了一种高频振动工具--用永磁体对微米管内表面进行光整加工，并阐明了光整行为。通过外部永磁体作用于磁铁刀具的精修力。此外，它还是一种利用电磁场给予磁铁刀具高频振动运动的新加工方法。观察了振动刀具的光整加工行为。分析了线圈励磁电流与磁力工具幅值的关系。阐明了工具振幅与磁体与工具之间距离的关系。表面粗糙度由15.6μm Rz提高到0.15μm Rz。

The capillary are used to micro-machines and micro-medical treatment machines, etc. However, there is not a processing technology which is able to finish up to 0.3μm Rz roughness of the internal surface. In this research, we pay attention to the creation of the precise internal finishing technology for micron tubes by the application of the magnetic abrasive finishing. The results of this research are as follows.1.The experimental setup of a internal magnetic field assisted finishing process for a micron tube, production of magnet tool and finishing experimentThe machining force is acted on the micron tube internal surface by the magnetic force between a permanent magnet and 0.1mm diameter piano wire tool. We made an experimental setup which the machining force acting on the piano wire tool could be controlled by adjusting the distance between a magnet and micron tube surface. In this study, a model experiment was carried out using a plane work to assume the curvature radius of tube to be infinity. The finishing characteristics were examined, and the surface roughness has been improved from 0.14μm Rz to 0.09μm Rz.2.Development of a high frequency vibration tool-for the finishing the internal surface of a micron tube using a permanent magnet and the elucidation of finishing behaviorThe experimental setup was produced, and a micron tube of 2mm inside diameter is used. The finishing force is acted to the magnet tool by an external permanent magnet. Moreover, it is a new processing method which gives the high frequency vibrating movement to the magnet tool by the electromagnetic field. The finishing behavior of the vibration tool was observed. The relation between coil excitation current and amplitude of magnet tool,. and the relation of the amplitude of the tool and the distance between magnets and the tool was clarified.. The surface roughness has been improved from 15.6μm Rz to 0.15μm Rz by this process.