新型磁流体水平传感器的研究与设计

磁流体作为一种新型的功能材料,兼具流动性和磁性,并具有许多独特的性质。利用永磁体在磁流体中受到二阶浮力可悬浮的特性,设计了一种新型的一维磁流体水平传感器。该磁流体水平传感器由外壳、芯体、磁流体和永磁体构成,芯体采用永磁体和铁芯组合而成。将芯体置入外壳中,在芯体两端部永磁体与外壳内壁间注入磁流体,磁流体产生二阶浮力使芯体径向稳定悬浮于外壳中,外壳端部永磁体与芯体端部永磁体间的磁斥力提供芯体轴向的回复力使芯体处于轴向平衡位置。当传感器偏离水平位置时,芯体将产生轴向位移并反映出倾角的大小。芯体中的铁芯和外部的电感线圈,可实现芯体位移的亚微米级检测。理论分析了其原理,设计并制作了实验样机。实验结果表明,-10~10°倾角范围内,检测分辨率可达0.03°。

Research and design of a novel magnetic fluid tilt sensor

Magnetic fluid is a new kind of functional material with fluidity, magnetism and many unique properties. Utilizing the property of that permanent magnet can be suspended in magnetic liquid caused by second order buoyancy, a novel one dimensional tilt magnetic liquid sensor is presented. The novel tilt level sensor is composed of a housing shell, a core part, magnetic fluid and the permanent magnets. The core part is made up of permanent magnet and iron core. The core part is placed inside the housing shell. The magnetic fluid is injected to the gaps between permanent magnet of the core body and the inner surface of the shell. The core body is suspended in the shell by the effect of the second order buoyancy of the magnetic fluid. The magnetic repulsion between the permanent magnet at the endpoint of the shell and the permanent magnet at the endpoint of the core part provides the restoring force of the core part along the axial of shell and keeps the core part at an equilibrium position. When the sensor tilts, the tilt angle will be reflected by the displacement of the core part. The sub micron displacement detection of the core part is implemented by means of the iron core inside the core part and the external inductance coil. On the basis of theoretical analysis, an experimental prototype sensor is made. The experimental results show that the resolution of the detection can be up to 0.03° within the angle range -10°~10°.