| 摘要 |
PURPOSE:To make possible a long-distance detection and to prevent a crack and a break in a magnet from being generated at the time of manufacture of the magnet by a method wherein a shaft member is constituted of a core part, a flange part and a shaft part and the core part is formed of a metallic material having the function of a yoke. CONSTITUTION:A composition containing rare earth permanent magnet powder and a thermoplastic resin as its main component is injection molded on a shaft member 12, which is first kept being inserted in a metal mold, and a cylindrical resin magnet 11 and the shaft member 12 are integrally molded. Then, a radial magnetization is performed to the magnet 11. Here, a metallic material, such as an SlOC and a soft magnetic stainless steel, having the function of a yoke is used for the core part of the member 12. The ratio T/W of the thickness T of a flange part 13 to the width W of the magnet 11 is set in the range of a ratio of 1:0 to 30. Moreover, one taper or two tapers or more is/are formed on the outer periphery of the core part of the member 12. Thereby, a long- distance detection can be made possible and a reduction in the yield of the magnet and the improvement of mountability of the magnet can be contrived. |
