Rolling mill and rolling method

Abstract

Provided are a plurality of hydraulic cylinders including drive side shift cylinders and work side shift cylinders all configured so as to apply force in an axial direction to a top work roll. The position of the top work roll in the axial direction is held by the drive side shift cylinders and the work side shift cylinders being moved in respective axial directions. The hydraulic circuit is configured such that, after the hydraulic circuit holds the position of the top work roll in the axial direction, in a case where the hydraulic cylinders from between the drive side shift cylinders or between the work side shift cylinders are put, by external force acting upon the top work roll, into a state in which the one hydraulic cylinder applies force in the axial direction to the top work roll, the other hydraulic cylinders are moved in the opposite direction.

1 . A rolling mill comprising:
 a mill roll;   a plurality of hydraulic cylinders including a drive side hydraulic cylinder that is configured to apply force in an axial direction to the mill roll and is provided on a drive side of the mill roll, and a work side hydraulic cylinder that is configured to apply force in the axial direction and is provided on a work side of the mill roll; and   a hydraulic circuit configured to send a hydraulic oil to the plurality of hydraulic cylinders so that the drive side hydraulic cylinder and the work side hydraulic cylinder move in the axial direction to hold a position of the mill roll in the axial direction, wherein   the hydraulic circuit is configured such that after the hydraulic circuit holds a position of the mill roll in the axial direction, in a case where only a hydraulic cylinder on one side between the drive side hydraulic cylinder and the work side hydraulic cylinder becomes a state of applying force in the axial direction to the mill roll due to external force received by the mill roll, a hydraulic cylinder on another side between the drive side hydraulic cylinder and the work side hydraulic cylinder moves in a direction opposite to the hydraulic cylinder on the one side.   
     
     
         2 . The rolling mill according to  claim 1 , wherein
 in the hydraulic circuit, a drive-side strip-side hydraulic oil chamber and a work-side side-opposite-to-strip hydraulic oil chamber are connected to each other through a pipe and a drive-side side-opposite-to-strip hydraulic oil chamber and a work-side strip-side hydraulic oil chamber are connected to each other through a pipe so that each of the drive side hydraulic cylinder and the work side hydraulic cylinder applies force to the mill roll in a same direction.   
     
     
         3 . The rolling mill according to  claim 2 , wherein
 the hydraulic circuit is configured such that when a hydraulic cylinder on one side between the drive side hydraulic cylinder and the work side hydraulic cylinder moves by a predetermined stroke, a hydraulic cylinder on another side between the drive side hydraulic cylinder and the work side hydraulic cylinder also moves in an opposite direction by the predetermined stroke without changing an amount of oil in the coupled pipes.   
     
     
         4 . The rolling mill according to  claim 1 , wherein
 the drive side hydraulic cylinder and the work side hydraulic cylinder are double rod cylinders,   a drive-side strip-side hydraulic oil chamber and a drive-side side-opposite-to-strip hydraulic oil chamber have a same cross-sectional area in a direction in which force of the hydraulic oil is applied,   a work-side strip-side hydraulic oil chamber and a work-side side-opposite-to-strip hydraulic oil chamber have a same cross-sectional area in a direction in which force of the hydraulic oil is applied, and   the drive-side strip-side hydraulic oil chamber and the work-side side-opposite-to-strip hydraulic oil chamber are connected to each other through a pipe, and the drive-side side-opposite-to-strip hydraulic oil chamber and the work-side strip-side hydraulic oil chamber are connected to each other through a pipe.   
     
     
         5 . The rolling mill according to  claim 1 , wherein
 the drive side hydraulic cylinder and the work side hydraulic cylinder are single rod cylinders,   orientations of a drive side hydraulic cylinder rod and a work side hydraulic cylinder rod are same,   a drive-side strip-side hydraulic oil chamber and a work-side side-opposite-to-strip hydraulic oil chamber are connected to each other through a pipe, and have a same cross-sectional area in a direction in which force of the hydraulic oil is applied, and   a drive-side side-opposite-to-strip hydraulic oil chamber and a work-side strip-side hydraulic oil chamber are connected to each other through a pipe, and have a same cross-sectional area in a direction in which force of the hydraulic oil is applied.   
     
     
         6 . The rolling mill according to  claim 1 , wherein
 the drive side hydraulic cylinder and the work side hydraulic cylinder are single rod cylinders,   orientations of a drive side hydraulic cylinder rod and a work side hydraulic cylinder rod are opposite to each other,   two or more single rod intermediate cylinders are provided,   a drive-side rod-side hydraulic oil chamber and a first intermediate cylinder rod side hydraulic oil chamber are connected to each other through a pipe,   a drive-side head-side hydraulic oil chamber and a second intermediate cylinder head side hydraulic oil chamber are connected to each other through a pipe,   a work-side rod-side hydraulic oil chamber and a second intermediate cylinder rod side hydraulic oil chamber are connected to each other through a pipe,   a work-side head-side hydraulic oil chamber and a first intermediate cylinder head side hydraulic oil chamber are connected to each other through a pipe, and   a ratio of a cross sectional area of the drive-side rod-side hydraulic oil chamber to a cross sectional area of the drive-side head-side hydraulic oil chamber in a direction in which force of the hydraulic oil is applied, a ratio of a cross sectional area of the work-side rod-side hydraulic oil chamber to a cross sectional area of the work-side head-side hydraulic oil chamber in a direction in which force of the hydraulic oil is applied, a ratio of a cross sectional area of the first intermediate cylinder rod side hydraulic oil chamber to a cross sectional area of the first intermediate cylinder head side hydraulic oil chamber in a direction in which force of the hydraulic oil is applied, and a ratio of a cross sectional area of the second intermediate cylinder rod side hydraulic oil chamber to a cross sectional area of the second intermediate cylinder head side hydraulic oil chamber in a direction in which force of the hydraulic oil is applied are same.   
     
     
         7 . The rolling mill according to  claim 6 , wherein
 a drive side hydraulic cylinder rod and a work-side hydraulic cylinder rod are configured to face outward in the axial direction.   
     
     
         8 . The rolling mill according to  claim 1 , wherein
 the drive side hydraulic cylinder and the work-side hydraulic cylinder are provided on each of an entry side and an exit side of the rolling mill, and   pipes for coupling corresponding hydraulic oil chambers on the entry side and the exit side are provided.   
     
     
         9 . The rolling mill according to  claim 1 , wherein
 a controller for controlling drive of the plurality of hydraulic cylinders is provided, and   the controller is configured to be capable of shifting the mill roll in the axial direction by causing the drive side hydraulic cylinder and the work-side hydraulic cylinder to be driven.   
     
     
         10 . The rolling mill according to  claim 1 , wherein
 a horizontal direction actuator for adjusting an angle of the mill roll in a horizontal direction is provided.   
     
     
         11 . A rolling method for a rolled metal strip by a rolling mill including:
 a mill roll;   a plurality of hydraulic cylinders including a drive side hydraulic cylinder that is configured to apply force in an axial direction to the mill roll and is provided on a drive side of the mill roll, and a work side hydraulic cylinder that is configured to apply force in the axial direction and is provided on a work side of the mill roll; and   a hydraulic circuit configured to send hydraulic oil to the plurality of hydraulic cylinders so that the drive side hydraulic cylinder and the work side hydraulic cylinder move in the axial direction to hold a position of the mill roll in the axial direction, the method comprising:   rolling the rolled metal strip by configuring the hydraulic circuit such that after the hydraulic circuit holds a position of the mill roll in the axial direction, in a case where only a hydraulic cylinder on one side between the drive side hydraulic cylinder and the work side hydraulic cylinder becomes a state of applying force in the axial direction to the mill roll due to external force received by the mill roll, a hydraulic cylinder on another side between the drive side hydraulic cylinder and the work side hydraulic cylinder moves in a direction opposite to the hydraulic cylinder on the one side.   
     
     
         12 . The rolling method according to  claim 11 , wherein
 the rolled metal strip is rolled by configuring the hydraulic circuit such that a drive-side strip-side hydraulic oil chamber and a work-side side-opposite-to-strip hydraulic oil chamber are connected to each other through a pipe and a drive-side side-opposite-to-strip hydraulic oil chamber and a work-side strip-side hydraulic oil chamber are connected to each other through a pipe so that each of the drive side hydraulic cylinder and the work side hydraulic cylinder applies force to the mill roll in a same direction.   
     
     
         13 . The rolling method according to  claim 12 , wherein
 the rolled metal strip is rolled by configuring the hydraulic circuit such that when a hydraulic cylinder on one side between the drive side hydraulic cylinder and the work side hydraulic cylinder moves by a predetermined stroke, a hydraulic cylinder on another side between the drive side hydraulic cylinder and the work side hydraulic cylinder also moves in an opposite direction by the predetermined stroke without changing an amount of oil in the coupled pipes.