| 摘要 |
PROBLEM TO BE SOLVED: To provide a sheet bar tail lower warpage detection device which is simple in structure, low in price, excellent in durability and reliability, and can properly detect the lower warpage of a sheet bar tail.SOLUTION: A transfer device 2 for transferring a sheet bar S by a transfer roller 4 is arranged between a roughing roller and a finish roller 1, light is projected from a projector 9 to a horizontal direction which crosses a transfer direction of the sheet bar S, and light projection/reception devices 8 for receiving the light by a light receiver 10 are arranged in a plurality of pieces while being upwardly aligned from a position higher than the transfer roller 4 being a lower position which is higher than a height of the sheet bar S. When a tail of the sheet bar S passes the light projection/reception devices 8, the light receiver 10 arranged at a position lower than the height of the sheet bar S is shifted to a light receiving state from a light non-receiving state, and when the light receiver is shifted to the light non-receiving state, it is determined that the tail of the sheet bar S is in a lower warpage state. A lower warpage amount of the sheet bar tail is calculated from a height of the light receiver 10 in the highest position when the light receiver is shifted to the light receiving state from the light non-receiving state, and a height of an upper end face of the transfer roller 4. |
