| 摘要 |
PURPOSE:To obtain the cylindrical permanent magnet having perfectly radial anisotropy and superior magnetic characteristic by a method wherein a kneaded material is extruded through a space consisting of dies and a core respectively made of a magnetic material, and is magnetized with an electromagnetic coil provided at the outer circumference of the die. CONSTITUTION:The kneaded material made of a magnetic powder containing an organic binder of about 0-2% is put in a hopper 1, the material is kneaded and compressed by a screw 2 and is cut by a shredder 3, while evacuated by a vacuum pump 5 in a vacuum chamber 4. Then the material is made to pass through a tapered barrel 7 by a screw 6 and is formed to a cylindrical form by dies 8, 10 and a core 9, and at this time radial magnetic line of force is formed at the space part 12 by the electromagnetic coil 11 provided at the outer circumference of the die 10. The formed body by the above-mentioned way is cut, dried and sintered to obtain the cylindrical permanent magnet. Accordingly the cylindrical radially anisotropic magnet having the uniform distribution of magnetic field intensity and a superior magnetic characteristic can be obtained. |
