| 摘要 |
PURPOSE:To execute rolling at a prescribed thickness in an early period by detecting the pressure drop of a hydraulic mechanism for applying roll bending of a rolling mill and opening a pressure control valve to restore quickly the loss of the bending force by the elongation of a mill housing when a rolling material engages with the rolling mill. CONSTITUTION:An oil pressure is exerted to a hydraulic cylinder 22 provided between the bearings of the rolling roll to bend the roll by which the rolling material is rolled at the prescribed thickness. The oil pressure of a hydraulic source 52 is stored in an accumulator 68 via a pressure reducing valve 66 and is applied to the cylinder 22 via oil pipes 64, 46 when a directional control valve 70 is opened, by which the prescribed roll bending pressure is exerted to the rolling material. The mill housing elongates instantaneously and the bending pressure is lost when the rolling material engages with the rolling mill but the pressure is restored to the prescribed oil pressure in the early period by actuating pressure control valve 50 upon detection 74 of the pressure drop. The rolling material is thus rolled at the prescribed thickness in the early period. |
