| 摘要 |
PURPOSE:To achieve high-precision and uniform finishing for the spherical surface of inside surface of a work by turning the magnetic poles faced to the working surface of the work thereby turning polishing brush body of magnetic abrasive grains formed along the magnetic flux. CONSTITUTION:A couple of N pole 2 and S pole 3 are energized with electric current to form electro-magnetic field in the gap 6, and magnetic abrasive grains are thrown into the gap 6. The magnetic abrasive grains are held along the magnetic flux formed between the convex portions 5 of the N and S poles. A polishing brush is formed by the rotation of a work 1 through the rotation of rotary axis 8. Then, by rotating the magnetic poles 2, 3, the magnetic flux formed between the convexes 5, 5 rotates, that is, the polishing brush body rotates on the working surface of the work 1. In the case that the work 1 has a spherical surface, the rotary axis 8 of fixing jig is inclined by the angle (alpha) against the axis line (O) perpendicular to the axis line of the magnetic poles, thereby the face of the work is inclined as shown by the single-dot chain line. With this, due to the rotation of the work together with the rotations of the magnetic poles and the polishing brush, the whole surface to be worked is polished in high precision. |
