| 摘要 |
<p>There is provided a proximity sensor with high accuracy without being subject to an influence due to variations of a magnet. A first yoke is insert-molded in an intermediate position between N and S magnetic pole faces of a magnet at injection-molding of the magnet as a rare-earth bond magnet, and a projecting portion of the first yoke projects from a wall face of the magnet vertical to the magnetic pole face. A protruding portion of a second yoke is provided to oppose the projecting portion to arrange a main body portion to be in parallel with the wall face of the magnet, and a hall IC having a direction of connecting the projecting portion and the protruding portion as a magnetic responsive direction is arranged in a space between the projecting portion and the protruding portion. When a detected member is away from the magnetic pole face, the magnetic flux traverses the magnetic responsive direction, but when the detected member is close to the magnetic pole face, the magnetic flux flows in the magnetic responsive direction between the protruding portion and projecting portion, and the hall IC detects a change in the magnetic flux density with high accuracy. Since the single magnet only is provided, the detection is not subject to an adverse influence due to the variation of each of magnets and the variation of the mounting thereof.</p> |
