| 摘要 |
<p>PURPOSE:To surely prevent erroneous action due to HMD flame. CONSTITUTION:In a hot lump detecting device provided with a photo-detection element that detects the radiation light emitted from a red-heated hot lump, and detecting, basing on the output signal from the photo-detecting element, presence of a hot lump, a specified action time set value to is set at an action signal decision device 5, for comparison with output signal action time tm from the photo-detecting element, and in case of less than the set action time set value to, action due to a flame 7 is assumed, and in case of more than the set action time set value to, action due to the hot lump 2 is assumed, and then an action contact point output signal 9 is outputted. With this, precision of a hot steel tube length measuring gauge improves, for improved tube manufacturing yield. In addition, mandrel bar hold/release timing of a boring/rolling machine is set properly, and occurrence of thickness variation with a hollow bare tube is reduced.</p> |
