| 摘要 |
<p>A device for detecting an abnormal portion in a metal strip, wherein a magnetizer (25) is provided in a manner to be opposed to this metal strip (12) being in contact with a roll (14c) for changing the running direction of the metal strip (12), whereby the metal strip (12) is magnetized by this magnetizer (25). Leakage magnetic fluxes attributed to an abnormal portion in the metal strip (12) thus magnetized are detected by a magnetic sensor (27). That is, the abnormal portion in this metal strip (12) is detected in a state where the metal strip (12) is wound around the outer peripheral surface (22) of the roll (14c). Furthermore, in a device for detecting an abnormal portion in a metal strip according to another invention, in addition to the above-described magnetizer (25) and magnetic sensor (27), there are added a plurality of comparators (29) for outputting abnormal detection signals when output signals from the respective magnetic sensors (7) exceed a predetermined threshold value, and a logic cicuit (34) for outputting a welded portion detection signal (c) when abnormal detection signals are output from all of these comparators (29).</p> |
