| 摘要 |
PURPOSE:To reduce rolling time and to improve the production efficiency of a seamless-pipe manufacturing installation by reforming a plug mill to speed up the opening and closing of rolling rolls. CONSTITUTION:Blocks 8, 8 having each a slant lower surface are provided to lower parts of a pair of rolling-reduction axes 7 respectively, to form a rolling-reduction-axis lower construction. Next, a wedge 20 has slant surfaces 20a, 20a, which contact the slant surfaces of blocks 8, 8 slidably, at its upper surface, and its lower surface contacts slidably the liners 13a, 13a placed at the inside bottom of a box 13. Further, the side faces of wedge 20 have locking projections 20b, 20b. Next, blocks 9, 9 and the box 13 are mounted on upper roll chocks 5, 5 vertically movably in one body, to form a roll-chock upper construction. Next, locking pins 21, 21 protrude to the inside of box 13 to engage with locking projections 20b, 20b, when the wedge 20 enters. Next, a piston 12 of cylinder 11 is interlocked with the wedge 20, and the pistons 23, 23 of cylinders 22, 22 are interlocked with the pins 21, 21. |
