静圧テーブルの運動誤差解析と高精度化 ２ 伝達関数を利用した解析法と修正研磨法の実験的検証

Abstract

An analytical model to predict motion accuracy of hydrostatic feed tables and a corrective lapping algorithm to improve their accuracy, which were proposed in the previous paper, are verified experimentally in the present research. Ahydrostatic feed table is developed, which has a single-sided guide in the vertical direction and a double-sided guide in the horizontal direction. Profiles of its guide rails are measured with a previously developed apparatus, which has a measuring accuracy of ± 0.03 μm. The averaging effect of oil film in the multiple pad table is clarified analytically by introducing 'motion error transfer function', which relates the motion error of the table with the rail profiles at each special fiequency. The motion errors of the table are simulated by the proposed analytical model in accordance with the measured profiles and the calculated motion error transfer function, and it is confirmed that the motion errors simulated in the vertical and horizontal directions are all in good agreement with the errors measured with a laser interferometer. Furthermore, the corrective lapping algorithm developed in the previous research is also verified experimentally by utilizing the developed feed table with a stroke of 145 mm, and straight motion accuracy of 0.07 pun and 1.42 arcsec is achieved for the double-sided guide, and 0.13 pin and 1.40 aresec for the single-sided guide after the corrective lapping.