Device for detecting defect in steel cord

A device for detecting a defect of a steel cord ply, configured to obtain an enhanced magnetic field signal of the steel cord ply and detect a defect of the steel cord ply based on the enhanced magnetic field signal, comprising:

• a magnetic field unit including a permanent magnet configured to generate a background magnetic field;
• a signal obtaining unit configured to generate an enhanced magnetic field signal of a steel cord ply based on a plurality of first magnetic field signals and a plurality of second magnetic field signals, wherein the signal obtaining unit includes:
• a magnetic sensor module configured to generate the plurality of first magnetic field signals and the plurality of second magnetic field signals,
• a differential module connected to the magnetic sensor module and configured to generate a plurality of differential magnetic field signals based on the plurality of first magnetic field signals and the plurality of second magnetic field signals, and
• a signal output module connected to the differential module and including input terminals configured to receive the plurality of differential magnetic field signals and at least one output terminal, wherein the signal output module is configured to generate and output the enhanced magnetic field signal based on the plurality of differential magnetic field signals;
• and
• a defect detecting unit configured to detect a defect in the steel cord ply based on the enhanced magnetic field signal, wherein the defect detecting unit includes an AD converting module, a signal processing module, a defect detecting module, a display module, and a control module;
• wherein a width of a cross-section of the permanent magnet along a moving direction of the steel cord ply is smaller than a spacing distance between adjacent steel cords of the steel cord ply along a moving direction of the steel cord ply;
• wherein the magnetic sensor module includes:
• a plurality of first magneto-sensitive elements configured to sense a change of a magnetic field caused by a movement of the steel cord ply in the background magnetic field and generate the plurality of first magnetic field signals;
• and
• a plurality of second magneto-sensitive elements configured to sense a change of a magnetic field caused by the movement of the steel cord ply in the background magnetic field and generate the plurality of second magnetic field signals,
• wherein the plurality of first magnetic field signals and the plurality of second magnetic field signals are electrical signals;
• wherein the plurality of first magneto-sensitive elements correspond to the plurality of second magneto-sensitive elements in a one-to-one way, and a spacing distance between each first magneto-sensitive element and a corresponding second magneto-sensitive element along a moving direction of the steel cord ply is half of a spacing distance between adjacent steel cords of the steel cord ply along the moving direction of the steel cord ply.