| 摘要 |
<p>A method of super-mirror finishing with electrolytic grinding for the internal surface of a small-diameter tube which comprises a rough grinding process and a mirror grinding process. In the rough grinding process, an electrode tool (14) for rough finishing having non-woven nylon fabric wound around a core electrode (15) thereof is used, wherein electrolytic grinding is applied to the inner surface of a small-diameter tube (10) with a minute electric current supplied through an electrolytic solution and is continued until the roughness of the inner surface of the tube is lowered to 0.5 νm Rmax or below while rotating the electrode tool (14) and the tube (10) relatively to each other and reciprocating relatively in the axial direction. In the subsequent mirror grinding process, finishing operation similar to the above operation is repeated with the use of an electrode tool for mirror finishing having urethane material wound around a core electrode thereof. According to this method, the surface roughness of about 3 νm Rmax is mirror-finished to about several tens of nm Rmax on account of exceedingly effective actions such as an electrolytic action with the use of the finishing tool and a mechanical grinding action depending on relative rotations of the tool (14) and the tube (10) as well as reciprocating movement thereof in the axial direction in the rough finishing process, and electrolytic and mechanical finishing actions with the use of the mirror finishing tool in the mirror finishing process to which processing is changed over from the preceding process at an appropriate time.</p> |
