Consideration on bent magnetic levitation apparatus for thin steel plate

Abstract

In the transport system of a thin steel plate production line, there is a problem that the quality of the plate surface deteriorates over time because the plate is usually in contact with rollers. Accordingly, studies of electromagnetic levitation technology have been carried out. However, when a flexible thin steel plate is targeted for levitation, levitation control becomes difficult because the thin plate undergoes increased flexure. To solve this problem, we proposed a levitation of a flexible thin steel plate that was bent to an extent which did not induce plastic deformation. Bent magnetic levitation apparatus was developed and bending levitation performance of thin steel plate was examined. Thin steel plates with a thickness of 0.18mm, 0.24mm, 0.27mm and 0.30mm were levitated to evaluate the relationship between tilt angle of electromagnets and levitation probability. Furthermore, to elucidate the optimal tilt angle of electromagnets, shapes of steel plates were analyzed using finite difference method and effective tilt angle was estimated. As a result, levitation probability increased by bending a steel plate to the extent that did not exceed natural deflection angle. Also, the optimal tilt angle of electromagnets can be estimated by shape analysis result and matched the experimental result. In developing the bent magnetic levitation apparatus, the optimal tilt angle of electromagnets was verified.

Keywords

• magnetic levitation
• vibration control
• optimal control
• thin steel plate
• bending levitation control