| 摘要 |
<p>PURPOSE:To detect minute defects of metal materials successively to improve their quality by equipping a piezoelectric element to convert elastic waves to electric signals, a processing device to analyse electric signals and a device to mark on the surface of metal by a command from the processing device or the like. CONSTITUTION:In the apparatus for molding metals, e.g. piezoelectric element 8 is attached to frame 2 of the rolling mill, elastic waves generated by defect 6 produced during rolling is sent to piezoelectric element 8 through roll 2, ball bearing 5 and frame 2 and converted to electric signals. The electric signals are sent to processing device 9 and the counting rate, hight of wave and frequency distribution are analyed in it. When a trouble is found as the result of analysis, a command to mark on the detected defect position is sent to marking device 11. Thus, defects generated during plastic processing of metal materials can be detected successively and the quality of products may be improved.</p> |
