| 摘要 |
PURPOSE:To stabilize characteristics and to improve mass-producibility by positioning the internal diameter of an upper plate and the top part of a center pole, and then perform resin molding by using forces wherein bodies obtained by bonding and combining magnets to plates are incorporated. CONSTITUTION:The internal diameter of an upper plate 4 is positioned at a bottom force 7 and a projection 8 is positioned by fitting the top part of a center pole 1 in the upper plate 4, thus incorporating the upper plate 4. Then, a body obtained by positioning and coupling a magnet 3 and a plate 2 together with an adhesive is incorporated with the center pole 1 fitted in the projection 8 and in this state, a top force 9 is combined with the bottom force 7. Melted resin is injected around the lamination of constituent parts to form a resin mold 5. Consequently, pressure generated during the injection of the melted resin stops the magnet 3 from shifting in position and the magnetic flux density distribution of the magnetic gap 6 is made uniform, thereby obtaining a magnetic circuit of high quality having stable characteristics. |
