| 摘要 |
<p>PURPOSE:To shorten a distance for changing plate thickness remarkably by calculating upper limit value of screw down speed corresponding to rolling load before changing plate thickness and estimated rolling load after changing the thickness by a specified approximation formula and controlling a hydraulic screw down device according to upper limit speed of small value. CONSTITUTION:Rolling load before changing and after changing plate thickness is calculated by an operator 11, and an upper limit value of screw down speed corresponding to these loads is calculated using a specified approximation formula that shows the relation between rolling load and upper limit of screw down speed, and the smaller value is made allowable screw down speed VS. Then, the time of changing and standard PS of rolling reduction are found basing on the speed VS in a change controlling device 10. When the passing distance of a rolling material 2 coincides with the set distance of change starting point, the standard PS is added to a position controlling device 4 of a hydraulic screw down device 3 by an in-rolling signal of a load gauge 7 and the signal of a pulse oscillator 8 of an electric motor 5. Thus, the plate thickness changing time is shortened and the changing distance is reduced remarkably, and the yield of production is improved sharply.</p> |
