| 摘要 |
PURPOSE:To provide abrasion resistance, enable noises to be absorbed and suppress attenuation of a magnetic force, by a construction wherein a vibration- damping alloy is provided between parts where mechanical contact of an electromagnet and an armature occurs, and an armature chamber is filled with a magnetic fluid. CONSTITUTION:When the armature 9 is returned from a released condition to an attracted condition, it strongly collides against an attracting surface of an iron core 6, so that the attracting surface is abraded and noise is generated. To avoid this, the vibration-damping alloy 15 consisting of a sintered non- magnetic 25Cr-20Ni austenitic steel material is fixed to the attracting surface so that it is intermediately located between the armature 9 and the attracting surface of the iron core 6. The alloy 15, because of its high damping capacity, reduces vibration and noise. In addition, the armature chamber 17 is filled with a magnetic fluid 18, whereby the magnetic force of the core 6 can be exerted on the armature 9 (with the alloy 15 therebetween) through the magnetic fluid 18. Accordingly, attenuation of the magnetic force on the armature 9 can be prevented, and a sound-deafening effect can be also expected. |
