| 摘要 |
<p>PURPOSE:To drive an electromagnet by low exciting currents by arranging a permanent magnet on the way of a magnetic circuit formed by an approximately E-shaped fixed core, external both sub-magnetic poles of which are extended, and a moving core and utilizing the attractive force of the permanent magnet for the drive operation of the electromagnet. CONSTITUTION:When a coil 3 is not excited, magnetic flux phi emitted from an N pole for a permanent magnet 10 reaches an S pole through a magnetic circuit C1. A sub-magnetic pole section 2b for a moving core 2 is held to a second sub-magnetic pole section IC by attractive force by magnetic flux phiin an abutting section 12. When the coil 3 is excited at that time, magnetic flux PHI is generated, a magnetic circuit C2 is formed, magnetic flux PHI and magnetic flux phi mutually deny in the abutting section 12 and attractive force to the core 2 is annihilated, and the core 2 is attracted and brought into contact to a fixed core 1. Accordingly, magnetic circuits C3, C4 are shaped, and the cores 1, 2 are held by attractive force obtained by adding magnetic flux phi, PHI. When the coil 3 is not excited, the core 2 is returned to an original state by a trip spring 8.</p> |
