| 摘要 |
PURPOSE:To obtain uniform thrust to the stroke even if the magnetomotive force of a coil is great, by providing a soft magnetic substance for shorting poles between the edges of wound coil of a moving substance not opposing a field magnet. CONSTITUTION:A spool 15 composed of a non-magnetic substance is provided non-contactly and movably against an iron core 12 by means of a guide, etc. A moving substance is constituted by winding a coil 16 around the spool 15. The part not facing a field magnet of the coil 16, i.e. the top and bottom parts of the coil 16, is surrounded by cylindrical soft magnetic substance 17 and 18 made up of iron sheets. No part of the flux generated from the coil 16 thereby go through the iron core 12 but loops inside the soft magnetic substances 17 and 18. The magnetomotive force of a coil will therefore look reduced if viewed from the iron core 12.
|
