| 摘要 |
<p>PURPOSE:To improve rolling quality by measuring a rolling load at skew rolls and adjusting a gap of guide shoes from a decrease starting point of rolling load measuring values as the start position to the rear tube end position. CONSTITUTION:A rolled tube stock, pierced by a piercer and into which a mandrel bar 20 is inserted, is stretch-rolled by skew rolls 11, 12. Guide shoes 31, 32 are provided with setting adjusters 41, 42, respectively; a guide gap etais adjusted by pressurized oil for control from a hydraulic pump 70. An arithmetic controller 50 adjusts oil pressures in hydraulic cylinders 41a, 42a based on the rolling load measured by the rolling load measuring device for the skew roll, to decrease the guide gap eta from a decrease starting point of rolling loads to the rear end of the tube stock. Hence, squaring phenomenon at the tube end part is improved and runout defects and roll stop during rolling are eliminated.</p> |
