Research on mine-used wire rope flaw detector based on Hall element

Abstract

In view of problem that current wire rope flaw detector cannot accurately detect whether the wire rope is damaged or not, a mine-used wire rope flaw detector based on Hall elements was designed according to magnetic flux leakage detection method. Permanent magnet magnetization wire rope is adopted. When the wire rope is damaged, there will be magnetic leakage at the damaged part. Hall element is used to collect magnetic leakage signal at the damaged part of the wire rope, and by analyzing output voltage waveform of Hall element it is determined whether the wire rope is damaged or not. In order to further improve detection accuracy of wire rope flaw detector, axial, circumferential and radial arrangement of the Hall element is optimized: uses Ansoft Maxwell to simulate magnetization condition of wire rope, the axial arrangement of Hall elements is determined based on simulation results, and the axial position of the Hall element is selected in center of the flaw detector. In order to eliminate inter-strand effect of wire rope, the circumferential arrangement of Hall elements is calculated and designed. The inter-strand effect can be basically eliminated when circumferential distance between two detection points is 29 mm. The radial arrangement of Hall element is studied by changing lifting distance through experiment. There will be jitter during movement of the wire rope, in order to prevent equipment from being damaged due to contact between the wire rope and the Hall element, the appropriate lifting distance should be selected to arrange the Hall element according to jitter of the wire rope. The experimental results show that the flaw detector can accurately detect whether the wire rope has damaged or not according to the signal mutation at the wire rope damage.

Keywords

• mine hoist
• wire rope detection
• flaw detector
• hall element
• magnetic flux leakage detection
• axial arrangement
• lifting distance