| 摘要 |
PURPOSE:To simplify mold construction, and to improve productivity by alternately combining and arranging members having different permeability in a mold cavity section and forming the difference of the degrees of orientation to moldings. CONSTITUTION:A mold cavity section is formed by a core 13 regulating the inner diameter of a molded shape and a wall section 11 consisting of a non- magnetic material controlling an outer diameter thereof, and members 9, 10 having different permeability are disposed alternately on the outside of the wall section 11. A mold 1 is arranged between pole pieces 3, 3' for coils 2, 2 for generating a magnetic field, and the coils 2, 2' are connected to a ferromagnetic material 5, thus shaping a closed magnetic circuit. Ferromagnetic material powder in a molding material injected into the cavity from an injection molding machine is subject to the influence of the members 9, 10 having different permeability on the outer circumference of the cavity, and the roughness and fineness of orientation having regularity are generated in the outer circumferential section of the molded shape. When the molded shape is magnetized so that a section having the high degree of orientation is used as the center of magnetization, a permanent magnet for a rotor is acquired. |
