Gyro finishing, which is one of the mass finishing, is expected to be an excellent finishing process of a workpiece with a complex shape. However, its fundamental researches are few, and hence the development of techniques to address its issues/problems, such as the decline of shape accuracy and low process controllability, is hindered by a lack of understanding of the process. Thus, a fundamental investigation of gyro finishing is conducted in the present research. The contact force acting on a cylindrical workpiece, which was designated by simplifying a large gear, was measured under different conditions in workpiece position, amount of abrasive media, and rotational speed of the container. In addition, the abrasive media height above the workpiece was measured, and effects of various factors on the contact force were investigated. From the results, the height above the workpiece was confirmed to have a strong correlation with the contact force. This was considered to be caused by increasing of the resistance of the abrasive media motion, and it was considered a major factor of the contact force. On the other hand, the effect of the abrasive media momentum and the distance between the workpiece and the container wall on the contact force was confirmed weak. Moreover, the variation of the surface roughness was investigated under different contact force conditions, and the improving speed of the surface roughness was faster under the higher contact force condition. Thus, contact force was a significant factor affecting the finishing performance, and this investigation featuring the contact force acting on the workpiece was considered significant to understand the gyro finishing process and to increase the contact force and the finishing performance.

陀螺精加工是批量精加工中的一种，有望成为形状复杂的工件的精加工。然而，其基础研究很少，因此缺乏对工艺的理解阻碍了解决其问题/问题（例如形状精度下降和工艺可控性低）的技术的发展。因此，在本研究中进行了陀螺精加工的基础研究。通过在不同的条件下测量工件位置，研磨介质的量和容器的旋转速度，来测量作用在圆柱工件上的接触力（通过简化大齿轮来指定）。另外，测量了工件上方的研磨介质高度，并研究了各种因素对接触力的影响。从结果可以确认，工件上方的高度与接触力有很强的相关性。认为这是由于磨料介质运动的阻力增加而引起的，并且被认为是接触力的主要因素。另一方面，证实了磨料动量和工件与容器壁之间的距离对接触力的影响较弱。此外，研究了在不同接触力条件下表面粗糙度的变化，在较高接触力条件下表面粗糙度的改善速度更快。因此，接触力是影响整理性能的重要因素，