| 摘要 |
PURPOSE:To smoothly stop a conveyance stand by a method wherein the relationship between an electromagnet on the primary side and a magnetic pole on the secondary side which correspond is constituted in such a way that an attractive force acts on one side with reference to a definite current for the electromagnet and that a repulsive force acts on the other. CONSTITUTION:A conveyance stand 11 is provided with magnetic poles 13c, 14c by a plurality of permanent magnets to be used as the secondary side, and a plurality of electromagnets 13, 14 to be used as the primary side are fixed onto a conveyance passage in stop positions with reference to the conveyance stand 11 which is advanced to a conveyance direction. Then, a definite exciting current is applied to coils 13b, 14c for the electromagnets 13, 14, and magnetic fluxes for stop are generated. In this case, the advance direction of the conveyance stand is displaced from a position in which the central line of a magnetic pole 13a for the electromagnet 13 on the primary side coincides with that of the magnetic pole 13c for the permanent magnet on the secondary side. Then, its displacement becomes positive, a repulsive force in the positive direction by the electromagnet 13 becomes large. When the displacement becomes larger, the repulsive force becomes gradually smaller. Inversely, when the conveyance stand 11 is displaced in the negative direction, the repulsive force of the electromagnet 13 is directed in the negative direction. As a result, the conveyance stand can be stopped smoothly in a stop point. |
