| 摘要 |
PURPOSE:To converge magnetic lines of force of a cylindrical unisotropic magnet in the outside circumference area by a method wherein a plurality of non- magnetic material pieces are provided to an inside circumference wall of a cylindrical pressure chamber and radial and partially converged magnetic fields are produced between the inside circumference wall and a center yoke. CONSTITUTION:A cylindrical pressure chamber 3 is formed by dies 1, 2 and a yoke 4. A plurality of non-magnetic material pieces 10 are provided to the inside circumference wall of the pressure chamber 3 with a prescribed interval. A core 5 made of a magnetic pipe is fitted on the outside circumference of the yoke 4. Magnetic powder mixture 6 is injected into the pressure chamber from an injection inlet 7. The magnetic powder mixture 6 is composed of thermoplastic synthetic resin and magnetic powder. Magnetic lines of force (a) are produced between the inside circumference wall of the pressure chamber 3 and the yoke 4 and partially converged. The magnetic powder mixture 6 is compressed and molded to be formed into a magnet roll. Magnetic lines of force of this magnet roll are converged in the outside circumference area. |
