| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the durability of an apparatus which flaw-detects a crack on a sleeve-type rolled roll such as high-speed steel or the like, to make a facility simple and low-cost and to increase the flaw detecting accuracy of the crack. SOLUTION: A crack on the surface of a sleeve-type rolled roll 3L which is built in a rolling mill is flaw-detected. At this time, when the crack is flaw- detected, an eddy-current flaw detecting sensor 11 is advanced from its retreat position by using an air cylinder 16 so as to be brought close to the surface of the sleeve-type rolled roll 3L. The crack is flaw-detected in a state that the interval between the eddy-current flaw detecting sensor 11 and the surface of the roll 3L is kept constant by an interval holding roller 18. After its flaw detection is finished, the eddy-current flaw detecting sensor 11 is retreated from its flaw detecting position by the air cylinder 16. Its flaw detecting position is set in an unrolled part in which the S/N ratio on the surface of the sleeve- type rolled roll 3L is high and in which the crack is flaw-detected and judged surely.</p> |
