| 摘要 |
<p>PURPOSE:To achieve a smaller return spring and effective utilization of attraction through a charged excitation coil by removing attracting force between mobile and fixed cores with a permanent magnet in returning of the mobile core. CONSTITUTION:A cylindrical bobbin 11 is wound with an excitation coil 12 with a dielectric pipe 13 inserted into a hollow-section thereof. A permanent magnet 15 is provided on a projected section of the pipe 13 through a magnetism collecting pole 14 and the excitation coil 12 and the permanent magnet 15 are surrounded with a yoke 16 having an opening on the side of the permanent magnet which is provided with a cover body 17 made of a magnetic material. A fixed core 18 is provided at the end of the opening of the bobbin 11 in contact with the yoke 16 while a mobile core 19 having a groove section 20 along the circumference thereof at the tip, for example, is inserted through the cover body 17 is such a manner as to be free to contact with or separate from the fixed core 18 through the other opening end of the bobbin 17. In addition, a groove 21 is provided at the tip of the core 19 for connecting with an external load and connected to a return spring through a connecting member 22.</p> |
