Development of Forming System for Micro Medical Tool Using Oblique Mill

本研究的目的是开发具有复杂和详细形状的医疗零件的系统。一般来说，立铣刀是用来制造这种形状的。特别是，商用立铣刀的最小尺寸为0.1 mm，研究水平为0.06 mm。因此，我提出了斜切轧机。这种工具的形状非常简单，是通过对角线切割圆柱形工具材料制成的。这种刀具的一个缺点是切削能力差。因此，在本研究中，研究了最佳切削条件。通过CCD型显微镜对切削现象的观察，了解了由于材料塑性变形导致的切削能力差和切屑去除率低的问题。从切削阻力和切屑去除角度看，最佳的斜角约为30度。对切削表面粗糙度进行了实验和理论分析。当斜角小，进给速度小时，表面粗糙度降低。考虑了防止切削表面产生大毛刺的对策。众所周知，通过优化进给速度，重复切削和刀具路径毛刺大大减少。开发了新型微切割系统，并验证了15-25 μm斜切铣刀可有效加工微槽和医用镊子等三维形状。一个普通的0.2毫米直径的微型立铣刀可以辅助上述制作。

The aim of this study is development of system to create medical parts with complicated and detailed shapes. Generally, the end mill is used for fabricating such shapes. In particular, The minimum size of commercial end-mills is 0.1 mm, and 0.06 at the research level. I thus proposed the oblique-cut mill. This tool has a very simple shape made by diagonally cutting a cylindrical tool material. One drawback of this tool is its poor cutting ability. In this study, the optimum cutting conditions were therefore investigated.1. As the result of observation of cutting phenomena by CCD- type microscope, the poor cutting ability due to plastic deformation of material and low chip removal rate are known.2. An optimum oblique angle is about 30 degree from the point of view or cutting resistance and chip removal.3. The roughness of cut surface is experimentally and theoretically analyzed. Surface roughness becomes lower in case of small oblique angle and small feed rate applied.4. The counter plan preventing from large burr generated at cut surface is considered. It is known that by optimizing feed rate, repeated cutting and tool path burr drastically diminished.5. New micro cutting system is developed and it was confirmed that the 15-25 μm oblique-cut mill is effective for fabricating micro groove and three-dimensional shapes such as medical forceps. An ordinary miniature end mill of 0.2 mm diameter can assist above fabrication.