| 摘要 |
PURPOSE:To change the buoyancy applied to a control piece in a magnetic fluid and noiselessly drive a driven body interlocked with the control piece without using a motor by adjusting the magnetic field applied to the magnetic fluid. CONSTITUTION:When an electromagnet 6 is excited by a thyristor 7, the magnetic lines of force 10 generated by the electromagnet 6 are made denser toward the electromagnet 6 and coarser toward the upper section, and a magnetic field gradient is applied to a magnetic fluid 5. At this time, a plunger 2 is slowly lifted with no vibration due to the viscosity of the magnetic fluid. When the cage of an elevator reaches the position of the second floor (2F), the electromagnet 6 controls the cage so that its floor position is not moved via the signal from a cage position detecting device. At the time of descent, the excitation of the electromagnet 6 is weakened or cut off, then the plunger is smoothly lowered. Noiseless drive control can be performed, and a drive control device is made very simple in structure and small-sized. |
