Nondestructive Testing of Steel Wire Rope Inside Elevator Drawn Steel Belt

The traction steel belt is more and more used in the elevator. To realize its effective nondestructive testing, the eddy current testing technology is applied to the detection of broken wires in the steel belt. An array eddy current sensor is designed, which has 24 groups of array cylindrical coils, which are staggered on the upper surface and the lower surface of a steel strip, and two coils in each group form a detection model of an up-down symmetrical differential bridge. The differential bridge circuit reflects the damaged condition of the wire rope through the differential voltage output by the bridge. the key problems of wire rope detection are studied in depth, and the sensors and detection devices are manufactured. The experimental results show that the device can accurately and effectively detect the smallest broken wire of the steel wire rope inside the steel belt, that is, the fracture of the thin steel wire with a diameter of 0.20 mm, and can judge the damage of multiple broken wires.