Study on Single-Point Machining Technology of Supersmooth Surface Using a Flying Tool

目前的超精密车削是基于运动仿形的概念，因此加工精度取决于机床的运动精度。超精密机床的精度低于10 nm，在不久的将来很难提高。然后，一个新的单点加工技术，使用飞行工具已被提出，以便把一个超光滑的表面，即使误差运动存在的机床。在此过程中，带有蓝宝石芯片的盘状滑块通过流体动力轴承的作用跟随预加工表面。本课题主要研究了该技术的切削机理：（1）切削刃高度保持在表面粗糙度的峰谷之间，通过截头提高了表面光洁度; (2)切削深度随工件表面的垂直加速度变化，具有较小的延迟，这对改善波纹度有一定的可能性。同时，为了测量工件在机床上的轮廓和加工过程中滑块的姿态，开发了一种新的采用二象限光电池的光学检测系统。该系统利用三角测量原理测量位移，利用光杠杆原理测量倾角。通过对角度的积分得到了曲面轮廓。与其他光学干涉测量方法的测量结果相比，该方法具有较高的重复性和可靠性。

The present ultraprecision turning is based on the concept of motion copying so that the machining accuracies depend on the motion accuracies of a machine tool. The accuracies of a ultraprecision machine tool is worse than 10nm and it is very difficult to improve that in the near future. Then, a new single-point machining technology using a flying tool has been proposed in order to turn a supersmooth surface even if error motions exist on the machine tool. In the process, a discoid slider with a sapphire chip follows the prefinished surface by the action of hydrodynamic bearing. In this research project, the cutting mechanism of the technology was investigated as follows :(1) The height of the cutting edge was kept between the peak and the vally of the surface roughness so that the surface finish was improved due to the truncation.(2) The cutting depth varied following the vertical acceleration of workpiece surface with small delay, which has some possibility of improving the waviness.At the same time, a new optical inspection system has been developed using two quadrant photocells in order to measure the profile of the workpiece on the machine and the posture of the slider in the process. In the system the displacement was measured applying the principle of triangulation and the inclination angle was detected applying the principle of optical lever. The Surface profile was obtained through the integration of the angle. The results had a high repeatability and a high reliability with comparison of the measured data using other optical interferometric method.