| 摘要 |
PURPOSE:To prevent the deterioration of the sensitivity of a sensor and to improve the accuracy of the measurement of material quality by measuring the Young's modulus or the r-value of a thin steel plate at a position immediately before the thin steel plate comes into contact with a roll, which bends the advance of the thin steel plate or immediately after the thin steel plate is separated from the roll. CONSTITUTION:A computer 6 determines the cutting length of a steel plate basing on the data from a length gage 3, a material-quality judging device 8 and a plate-thickness gage 7 and gives the cutting command to a cut shear 5. The sensor part of the material-quality judging device 8 is not in contact with the steel plate, and the longitudinal wave and the lateral wave, which are propagating through the steel plate, are measured. The quality of the steel plate is measured basing on the measured value of the plate thickness from the plate-thickness gage 7. At this time, the sensor of the material-quality judging device 8 is provided at a position, which is slightly deviated from the position, where a roll 4 is in contact with the steel plate. Thus, the position, where the roll 4 and the steel plate are in contact, is avoided, and the absorption of the propagating wave through the steel plate into the roll 4 is prevented. The large change in distance between the steel plate and the sensor of the material-quality judging device 8 caused by the fluttering of the steel plate is prevented. |
