| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electromagnet of high reliability and an operating mechanism for an open/close device by solving the problem that a reversely magnetizing magnetic flux penetrates only the periphery of an iron core due to a skin effect, a residual magnetic flux is large, and a canceling speed becomes low in a conventional electromagnet which keeps an attraction state with a permanent magnet and cancels an attraction state by reverse magnetization. SOLUTION: An electromagnet 1 is composed of a solenoid coil 4, a plunger 2a penetrating through the solenoid coil 4, and a stationary iron core 3 arranged so as to cover the solenoid coil 4. The solenoid coil 4 is excited to attract the plunger 2a, a magnetic flux generated by a permanent magnet 6 is made to pass through the plunger 2a and the opposed surface of the center leg 3d of the stationary iron core 3 to keep an attraction state, and a current flowing in the direction opposite to that of a current flowing in an attraction state is made to flow through the solenoid coil 4 to release the plunger 2a. A gap is provided at the center of either the plunger 2a or the center leg 3d, and a magnetic flux generated by the permanent magnet 6 is made to flow through the periphery with concentration. In an attraction state, the magnetic fluxΦm of the permanent magnet 6 flows through the periphery of an iron core on the opposed surface with concentration, so that a releasing speed is increased.</p> |
