US20210001388A1 - Rolling mill and method of controlling the same - Google Patents
Rolling mill and method of controlling the same Download PDFInfo
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- US20210001388A1 US20210001388A1 US16/979,438 US201916979438A US2021001388A1 US 20210001388 A1 US20210001388 A1 US 20210001388A1 US 201916979438 A US201916979438 A US 201916979438A US 2021001388 A1 US2021001388 A1 US 2021001388A1
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- Prior art keywords
- roll
- rolling
- hydraulic press
- press cylinder
- rolling mill
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/58—Roll-force control; Roll-gap control
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/58—Roll-force control; Roll-gap control
- B21B37/62—Roll-force control; Roll-gap control by control of a hydraulic adjusting device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
- B21B13/02—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories with axes of rolls arranged horizontally
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
- B21B38/12—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring roll camber
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C51/00—Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B2269/00—Roll bending or shifting
- B21B2269/02—Roll bending; vertical bending of rolls
Definitions
- the present invention relates to a rolling mill and a method of controlling the rolling mill.
- a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, has already been widely available.
- Patent Document 1 Japanese Examined Utility Model Publication No. H06-46567 (JP 06-46567 Y (1994))
- the present invention has been made in consideration of such a problem and an object of the present invention is to achieve highly-accurate shape control in rolling a bar steel with the use of an offset rolling mill.
- a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, the rolling mill being characterized in that
- a rolling area for rolling the bar steel which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other, and
- the rolling mill further includes:
- a distance sensor configured to measure a roll deflection in the rolling area of at least one of the first roll and the second roll
- a controller configured to control an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on a detection value of the distance sensor.
- FIG. 1 is a schematic front view of a rolling mill 10 according to an embodiment
- FIG. 2 is a diagram showing relation between a controller 40 and other devices of the rolling mill 10 ;
- FIG. 3 includes an upper drawing that is a diagram showing a state where rolling is performed with a roll pair sandwiching a bar steel 1 in a bent state, and a lower drawing that is an explanatory diagram for explaining roll deflections of a first roll 14 a;
- FIG. 4 is a schematic front view of a rolling mill 10 according to a second embodiment.
- FIG. 5 is a schematic front view of the rolling mill 10 according to a third embodiment.
- a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, is characterized in that
- a rolling area for rolling the bar steel which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other, and
- the rolling mill further includes:
- a distance sensor configured to measure a roll deflection in the rolling area of at least one of the first roll and the second roll
- a controller configured to control an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on a detection value of the distance sensor.
- a plurality of the rolling areas may be set at different positions in the longitudinal direction of the roll pair.
- At least one distance sensor may be provided for each of the plurality of rolling areas set at the different positions.
- the above-described rolling mill may further include a movably-supporting device that supports the distance sensor movably in the longitudinal direction.
- the movably-supporting device may include: a mounting portion, to which the distance sensor is fixed; a rail portion, with which the mounting portion slidably engages; and a driving device for moving the mounting portion along the rail portion.
- the above-described rolling mill may be configured to be able to measure the roll deflections in both end portions of the rolling area in the longitudinal direction.
- the rolling mill it is made possible to determine the thicknesses of both edge portions of the bar steel in the longitudinal direction based on the roll deflections in both end portions of the rolling area in the longitudinal direction, so that it is made possible to make these thicknesses of both edge portions of the bar steel in the longitudinal direction more even.
- the controller may be configured to control the amount of depression of the first hydraulic press cylinder and the amount of depression of the second hydraulic press cylinder in real time while the bar steel is rolled.
- each of the first roll and the second roll may be provided with a caliber in the rolling area.
- the present invention is more effective because, when rolling is performed with the use of a roll pair provided with the calibers, the rolling is usually, or often, performed with the use of an offset rolling mill.
- a method of controlling a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, is characterized by including:
- a rolling area for rolling the bar steel which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other;
- a rolling mill 10 according to this embodiment is an apparatus for rolling a bar steel 1 to be rolled and is used as an offset rolling mill.
- This offset rolling mill means the rolling mill 10 characterized by the position of the bar steel 1 during rolling, which will be described in detail later.
- the bar steel 1 include flat steel, section steel, steel rods, wires, rails, and the like, meaning steel material with a shape having a very large length as compared to the size of the cross-sectional area.
- flat steel is rolled as the bar steel 1 .
- FIG. 1 is a schematic front view of the rolling mill 10 according to this embodiment.
- lateral direction (horizontal direction) on the sheet is defined as “longitudinal direction,” and the left (right) side on the sheet is referred to as “WS (DS)” or “left (right),” while vertical direction on the sheet is defined as “vertical direction,” and the upper (lower) side on the sheet is referred to as “upper (lower) side.”
- FIG. 2 is a diagram showing relation between a controller 40 and other devices of the rolling mill 10 .
- a housing 11 of the rolling mill 10 is shown in FIG. 1 .
- Disposed in the housing 11 (inside the housing 11 ) are a pair of rolls (a first roll 14 a and a second roll 14 b ), supporting portions (a first supporting portion 13 a , a second supporting portion 13 b , and supporting portions for the second roll 14 b ), hydraulic press cylinders (a first hydraulic press cylinder 12 a and a second hydraulic press cylinder 12 b ), load cells (a first load cell 15 a and a second load cell 15 b ), distance sensors 20 , a movably-supporting device 30 , and a balance cylinder mechanism 50 , which are included in the rolling mill 10 .
- the roll pair is a pair of upper and lower flat rolls, the first roll 14 a and the second roll 14 b .
- the first roll 14 a and the second roll 14 b are the same in shape and each has a rolling portion with a larger diameter and shaft portions with a smaller diameter, the shaft portions being provided at both ends of the rolling portion in the longitudinal direction.
- the roll pair catches the bar steel 1 in the gap between the first roll 14 a provided on the upper side and the second roll 14 b provided on the lower side as shown in FIG. 1 , and is rotated for rolling by the rotation driven by a driving portion 32 shown in FIG. 2 .
- the rolling mill 10 includes the roll pair of the first roll 14 a and the second roll 14 b for rolling the bar steel 1 to be rolled.
- a plurality of partial continuous areas, corresponding to rolling areas AP, are set in the longitudinal direction of the rolling portions of the roll pair as positions in the longitudinal direction of the roll pair, between which the bar steel 1 is passed, and are stored in a memory unit 41 described later.
- a plurality of the rolling areas AP are set at different positions in the longitudinal direction of the roll pair.
- the supporting portions support both ends of each of the rolls of the roll pair in a state where the roll pair are rotatable, so that the roll pair can be rotated by the rotation driven by the driving portion 32 .
- “both ends of the roll” supported by the supporting portions mean the positions that are symmetric with respect to a roll center line RC (the center line in the longitudinal direction of the roll pair), in other words, the shaft portions (that is, not the rolling portion).
- the WS shaft portion of the first roll 14 a is supported by the first supporting portion 13 a and the DS shaft portion thereof is supported by the second supporting portion 13 b .
- These supporting portions are connected to the hydraulic press cylinders with a balance beam 51 interposed therebetween, which will be described later.
- Both ends of the second roll 14 b are supported by the supporting portions for the second roll 14 b that are fixed to a lower surface of a housing 11 (lower surface of the inside of the housing 11 ).
- the hydraulic press cylinders (the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b ), which are devices for moving the first roll 14 a relative to the second roll 14 b , are fixed to an upper side surface of the housing 11 (upper side surface of the inside of the housing 11 ) with the load cells, described later, interposed therebetween.
- the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b are respectively connected to the first supporting portion 13 a and the second supporting portion 13 b and cause the first roll 14 a to move relative to the second roll 14 b by moving the supporting portions, to which the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b are connected.
- the rolling mill 10 includes the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b for moving the first roll 14 a relative to the second roll 14 b , the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b being respectively connected to the first supporting portion 13 a and the second supporting portion 13 b that rotatably support the first roll 14 a at both ends of the first roll 14 a.
- the load cells (the first load cell 15 a and the second load cell 15 b ), which are sensors for detecting the pressure applied to the supporting portions by the hydraulic press cylinders connected thereto, are interposed between the housing 11 and the hydraulic press cylinders.
- the first load cell 15 a is provided between an upper side surface (installation surface) of the first hydraulic press cylinder 12 a and the upper side surface of the housing 11
- the second load cell 15 b is provided between an upper side surface (installation surface) of the second hydraulic press cylinder 12 b and the upper side surface of the housing 11 .
- the load cells continuously detect the pressure (reaction force to the pressure applied to the supporting portions by the hydraulic press cylinders connected thereto), at which the load cells are pressed between the housing 11 and the hydraulic press cylinders, as pressure values, at which the hydraulic press cylinders apply the pressure to the connected supporting portions.
- the load cells immediately transmit the detection results to the controller 40 .
- the controller 40 has an automatic gap control (AGC) function and can perform compensation, based on the pressure detected by the load cells, by the amount of vertical displacement of the first supporting portion 13 a and the second supporting portion 13 b , the displacement being caused by vertical elongation (vertical deformation) of the housing 11 .
- AGC automatic gap control
- the controller 40 having received the pressure values detected by the load cells calculates the amount of vertical deformation of the housing 11 and the amount of vertical deformation of bearings of the supporting portions (members for rotatably supporting the first roll 14 a ), which are not shown, with the use of the detected pressure values.
- the controller 40 then corrects the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b with the use of the calculated amounts of vertical deformation. Note that the deformation of the bearing is calculated based on a graph between load and radial displacement of the bearing and the detected pressure values.
- the distance sensors 20 are sensors for measuring the roll deflections, each detecting the distance between the distance sensor 20 and the roll.
- the “roll deflection” herein means the difference between the vertical position of the roll that is measured by a detection value of the distance sensor 20 in a state where the roll pair is not bent (hereinafter also referred to as the “zero-deflection state”) and the vertical position of the roll that is measured by the detection value of the distance sensor 20 in a state where the roll pair is bent.
- the distance sensors 20 are fixed to mounting portions 30 a of the movably-supporting device 30 , which will be described later, provided above the first roll 14 a .
- two distance sensors 20 Over one end portion and the other end portion, in the longitudinal direction, of the rolling area AP for the bar steel 1 to be rolled (both end portions of the rolling area AP), two distance sensors 20 , one over each end portion, are provided. Accordingly, the distance sensors 20 detect the distances to the first roll 14 a in both end portions of the rolling area AP and transmit the detected distances to the controller 40 .
- eddy-current displacement sensors, laser distance sensors, or the like can be used as the distance sensors 20 .
- the movably-supporting device 30 is provided on the lower side surface of the balance beam 51 , which is positioned above the first roll 14 a and will be described later, so as to be extended between both end portions, one end portion and the other end portion, of the first roll 14 a .
- the movably-supporting device 30 includes the mounting portions 30 a , to which the distance sensors 20 are fixed, a rail portion 30 b , with which the mounting portions 30 a slidably engage, and driving devices (not shown) for moving the mounting portions 30 a along the rail portion 30 b .
- the movably-supporting device 30 is a device for moving the distance sensors 20 between both end portions, one end portion and the other end portion, of the first roll 14 a above the first roll 14 a .
- both end portions of the roll mean both end portions of the rolling portion of the roll (that is, not the shaft portions).
- One mounting portion 30 a and one driving device are provided for each distance sensor 20 .
- a plurality of the mounting portions 30 a can slidably engage one rail portion 30 b . This means that the plurality of mounting portions 30 a (distance sensors 20 ) engaging with the rail portion 30 b are moved along the rail portion 30 b by the driving devices between the one end portion and the other end portion of the rolling portion of the first roll 14 a .
- the rolling mill 10 includes the movably-supporting device 30 supporting the distance sensors 20 movably along the longitudinal direction.
- the movably-supporting device 30 has a position detection function of detecting positions of the mounting portions 30 a in the longitudinal direction and the position information obtained by the detection is transmitted to the controller 40 .
- the controller 40 it is possible to move the mounting portions 30 a carrying the distance sensors 20 along the rail portion 30 b to the instructed positions in the longitudinal direction between the one end portion and the other end portion of the rolling portion by the driving devices as drivers according to instructions from the controller 40 .
- the controller 40 shown in FIG. 2 is included in the rolling mill 10 and receives information transmitted from various devices as described above.
- the controller 40 has the memory unit 41 that stores the information, and an arithmetic unit 42 that performs calculation with the use of the received information, the information stored in the memory unit 41 , etc.
- the controller 40 sends instructions to the various devices based on the results of calculation by the arithmetic unit 42 , etc. In other words, the controller 40 controls the various devices included in the rolling mill 10 based on the various kinds of information.
- the balance cylinder mechanism 50 includes a first balance cylinder 50 a , a second balance cylinder 50 b , and the balance beam 51 .
- the first balance cylinder 50 a and the second balance cylinder 50 b are fixed to the upper side surface of the housing 11 so as to be positioned symmetrically with respect to the roll center line RC, and the vertically-movable cylinder portions of the first balance cylinder 50 a and the second balance cylinder 50 b are connected to the balance beam 51 .
- the balance beam 51 is provided so as to be extended from the first supporting portion 13 a to the second supporting portion 13 b in the longitudinal direction and is configured to, when rolling is not performed, raise the first supporting portion 13 a and the second supporting portion 13 b so as to maintain a gap between the first roll 14 a and the second roll 14 b .
- the balance beam 51 is also moved accordingly.
- the balance beam 51 is also connected to the first balance cylinder 50 a and the second balance cylinder 50 b so that the balance beam 51 can pivot about pivot axes extending along the direction perpendicular to the sheet of FIG. 1 .
- each rolling area AP is set so that the center of the rolling area AP in the longitudinal direction does not coincide with the roll center line RC.
- each rolling area AP is set so that both end portions of the rolling area AP are positioned asymmetrically with respect to the roll center line RC.
- the rolling area AP for rolling the bar steel 1 which is set in a partial continuous area in the longitudinal direction of the roll pair, is positioned so that the distance between the first supporting portion 13 a and the rolling area AP and the distance between the second supporting portion 13 b and the rolling area AP differ from each other because the first supporting portion 13 a and the second supporting portion 13 b are provided symmetrically with respect to the roll center line RC.
- a method of controlling the offset rolling mill (the rolling mill 10 shown in FIG. 1 that shows a state where the bar steel 1 is rolled at one of the set rolling areas AP) will be described below.
- the upper drawing of FIG. 3 is a diagram showing a state where rolling is performed with the roll pair sandwiching the bar steel 1 in a bent state.
- the lower drawing of FIG. 3 is an explanatory diagram for explaining the roll deflections of the first roll 14 a . While the roll pair during ordinary rolling is not deflected so greatly as shown in the upper and lower drawings of FIG. 3 , the deflections are exaggerated for ease of understanding.
- the first roll 14 a is bent so that the central portion (at the roll center line RC) of the first roll 14 a is positioned upward and both ends thereof are positioned downward
- the second roll 14 b is bent so that the central portion of the second roll 14 b is positioned downward and both ends thereof are positioned upward.
- control is performed so that the thickness of the bar steel 1 rolled by the offset rolling mill shown in FIG. 1 becomes a predetermined dimension and the thicknesses of both edge portions of the bar steel 1 in the longitudinal direction become equal to each other. Steps of the control will be described in order below.
- a rolling area AP shown in FIG. 1 is selected as the rolling area AP to be used from among the plurality of rolling areas AP set in the rolling mill 10 .
- the controller 40 of the rolling mill 10 then disposes, or moves, the distance sensors 20 to the positions corresponding to both end portions, one end portion and the other end portion, of the selected rolling area AP in the longitudinal direction.
- the rolling mill 10 is configured to be able to measure the roll deflections in both end portions of the rolling area AP in the longitudinal direction.
- the selection of the rolling area AP to be used may be performed manually, or may be performed, for example, based on the results of detection by a sensor for detecting the rolling area AP of the bar steel 1 , the sensor being provided on the upstream side of the roll pair in the travel direction of the bar steel 1 (direction perpendicular to the sheet in FIG. 1 ).
- the controller 40 detects the values from the distance sensors 20 in “the state where the roll pair is not bent (zero-deflection state)” described above, and stores the values to the memory unit 41 in advance of rolling.
- the controller 40 then starts rolling the bar steel 1 in the rolling mill 10 .
- two distance sensors 20 positioned over a first detection point P 1 and a second detection point P 2 shown in the upper and lower drawings of FIG. 3 (positioned over both end portions of the rolling area AP) detect the distances to the first roll 14 a and transmit the detected values to the controller 40 .
- the controller 40 having received the detected values of the first detection point P 1 and the second detection point P 2 measures, or calculates, a first roll deflection X 1 from the detected value of the first detection point P 1 and a second roll deflection X 2 from the detected value of the second detection point P 2 .
- the dashed straight line extending in the longitudinal direction shown in the lower drawing of FIG. 3 is a straight line (hereinafter also referred to as the “reference line BL”) expressing the position of the first roll 14 a in a zero-deflection state.
- the first roll deflection X 1 and the second roll deflection X 2 are values by which the detection values of the distance sensors 20 received by the controller 40 during rolling differ from the detection values of the distance sensors 20 obtained in the zero-deflection state.
- the controller 40 having measured the first roll deflection X 1 and the second roll deflection X 2 calculates the amount of depression (compensation amount) of the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b so that the thicknesses of both edge portions of the bar steel 1 in the longitudinal direction are equalized.
- the arithmetic unit 42 calculates the inclination (corresponding to the inclination S 1 between both end portions) between the first detection point P 1 and the second detection point P 2 in the longitudinal direction with respect to the reference line BL from the first roll deflection X 1 and the second roll deflection X 2 with the use of the following equation.
- the first distance L 1 is the distance between the first detection point P 1 and the roll center line RC in the longitudinal direction
- the second distance L 2 is the distance between the second detection point P 2 and the roll center line RC.
- a supporting-portion distance L which is used in an equation described later, is the distance between the first supporting portion 13 a and the roll center line RC in the longitudinal direction.
- the arithmetic unit 42 having calculated the inclination S 1 between both end portions calculates compensation values in the vertical direction for the first supporting portion 13 a and the second supporting portion 13 b with the use of the following equations.
- the controller 40 then causes the supporting portions connected to the respective hydraulic press cylinders to move in the vertical direction based on the calculated compensation values. Specifically, the amount of depression is increased by the average roll deflection and the first supporting portion 13 a and the second supporting portion 13 b are moved in the vertical direction so as to make the inclination S 1 between both end portions parallel to the reference line BL.
- the compensation amount for the first hydraulic press cylinder 12 a is the sum of the increase of the amount of depression (positive value) corresponding to the average roll deflection, which compensates for shortage of the amount of depression caused by deflection of the rolls, and the increase of the amount of depression (negative value) to make the inclination S 1 between both end portions parallel to the reference line BL.
- this sum is positive, the amount of depression of the first hydraulic press cylinder 12 a is increased, so that the first supporting portion 13 a is additionally moved downward by the compensation amount.
- this sum is negative, the amount of depression of the first hydraulic press cylinder 12 a is reduced, so that the first supporting portion 13 a is moved upward by the compensation amount.
- the compensation amount for the second hydraulic press cylinder 12 b is the sum of the increase of the amount of depression (positive value) corresponding to the average roll deflection, which compensates for shortage of the amount of depression caused by deflection of the rolls, and the increase of the amount of depression (positive value) to make the inclination S 1 between both end portions parallel to the reference line BL. This means that the amount of depression of the second hydraulic press cylinder 12 b is increased, and therefore, the second supporting portion 13 b is additionally moved downward by the compensation amount.
- the second roll 14 b is also bent as in the case of the first roll 14 a , and therefore, it is also necessary to perform correction (control) of the hydraulic press cylinders, focusing on the second roll 14 b .
- the second roll 14 b is also bent similarly to the first roll 14 a .
- the rolls are bent symmetrically in the vertical direction with respect to the center line of the bar steel 1 in the thickness direction (vertical direction).
- the first roll 14 a is moved in the vertical direction by the sum of the amount corresponding to the deflection of the first roll 14 a and the amount corresponding to the deflection of the second roll 14 b (that is, twice of the amount corresponding to the deflection of the first roll 14 a ).
- This makes it possible to perform control the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b , focusing on both of the first roll 14 a and the second roll 14 b.
- the controller 40 controls the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b based on the detection values of the distance sensors 20 so as to reduce the dimensional error of the bar steel 1 by compensating for shortage of the amount of depression caused by deflection of the rolls and to improve accuracy in shape of the cross section by reducing the inclination of the first roll 14 a between both end portions of the rolling area AP in the longitudinal direction set in the first roll 14 a and reducing the inclination of the second roll 14 b between both end portions of the rolling area AP in the longitudinal direction set in the second roll 14 b.
- the controller 40 When the controller 40 according to this embodiment receives the information on distance at the first detection point P 1 and the second detection point P 2 from the distance sensors 20 , the controller 40 immediately calculates the compensation amount at the arithmetic unit 42 . When compensation is needed, the controller 40 controls the amount of depression of the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b and waits for the next transmission from the distance sensors 20 . The distance sensors 20 continuously detect the distance to the first detection point P 1 and the distance to the second detection point P 2 and immediately transmit the detection results to the controller 40 . In other words, the controller 40 controls the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b in real time while the bar steel 1 is rolled.
- the rolling mill 10 includes: the roll pair having the first roll 14 a and the second roll 14 b for rolling the bar steel 1 to be rolled; and the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b for moving the first roll 14 a relative to the second roll 14 b , the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b being respectively connected to the first supporting portion 13 a and the second supporting portion 13 b that rotatably support the first roll 14 a at both ends of the first roll 14 a .
- each of the rolling areas AP for rolling the bar steel 1 is positioned so that the distance between the first supporting portion 13 a and the rolling area AP and the distance between the second supporting portion 13 b and the rolling area AP differ from each other.
- the rolling mill 10 further includes the distance sensors 20 configured to measure the roll deflections at the rolling areas AP of the first roll 14 a , and the controller 40 configured to control the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b based on the detection values of the distance sensors 20 . Accordingly, it is made possible to achieve highly-accurate shape control in rolling the bar steel 1 with the use of the offset rolling mill.
- the rolling mill 10 includes the distance sensors 20 configured to measure the roll deflections at the rolling areas AP of the first roll 14 a , and the controller 40 configured to control the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b based on the detection values of the distance sensors 20 .
- the controller 40 configured to control the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b based on the detection values of the distance sensors 20 .
- controller 40 controls the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b in accordance with the roll deflections, it is made possible to achieve highly-accurate shape control in rolling the bar steel 1 with the use of the offset rolling mill.
- the rolling mill 10 is configured to be able to measure the roll deflections in both end portions of the rolling area AP in the longitudinal direction. Accordingly, by correcting the amount of depression of the hydraulic press cylinders based on the roll deflections in both end portions of the rolling area AP in the longitudinal direction, it is made possible to reduce the dimensional error of the bar steel 1 by compensating for shortage of the amount of depression caused by deflection of the rolls and to reduce the inclination of the first roll 14 a between both end portions of the rolling area AP in the longitudinal direction set in the first roll 14 a and the inclination of the second roll 14 b between both end portions of the rolling area AP in the longitudinal direction set in the second roll 14 b , which makes it possible to achieve highly-accurate shape control.
- the controller 40 controls the amount of depression of the first hydraulic press cylinder 12 a and the amount of depression of the second hydraulic press cylinder 12 b in real time while the bar steel 1 is rolled. Since the controller 40 controls the amount of depression of the hydraulic press cylinders in real time, control is swiftly performed when it becomes necessary to control the amount of depression of the hydraulic press cylinders. This means that more accurate shape control is achieved in rolling the bar steel 1 with the use of the offset rolling mill.
- the rolling areas AP are set at different positions in the longitudinal direction of the roll pair and the present invention can be applied to all the rolling areas AP set at the different positions in the longitudinal direction of the roll pair. This means that it is possible to achieve highly-accurate shape control regardless in which of the rolling areas AP the bar steel 1 is rolled.
- the rolling mill 10 includes the movably-supporting device 30 that supports the distance sensors 20 movably in the longitudinal direction.
- the movably-supporting device 30 can move the distance sensors 20 to the rolling area AP after the switch and the moved distance sensors 20 can detect the values at the rolling area AP after switch. Accordingly, it is possible to reduce the number of distance sensors 20 as compared to the case where the distance sensors 20 are provided for every one of the plurality of rolling areas AP.
- the movably-supporting device 30 includes the mounting portions 30 a , to which the distance sensors 20 are fixed, the rail portion 30 b , with which the mounting portions 30 a slidably engage, and the driving devices for moving the mounting portions 30 a along the rail portion 30 b .
- the roll pair is made up of the flat rolls in the above-described embodiment, the present invention is not limited to this configuration.
- the roll pair may be provided with calibers (grooves provided in the roll pair and formed in the same cross-sectional shape as that of the bar steel 1 , for forming the cross-sectional shape of the bar steel 1 by passing the bar steel 1 through the grooves; the grooves correspond to the rolling areas AP).
- Each of the first roll 14 a and the second roll 14 b may be provided with the caliber(s) in the rolling area(s) AP.
- the rolling is usually, or often, performed with the use of an offset rolling mill and therefore, the present invention is more effective.
- the present invention is not limited to this configuration.
- the position of the movably-supporting device 30 may be changed and a first supporting-portion balance cylinder 60 a and a second supporting-portion balance cylinder 60 b may be provided instead of the balance cylinder mechanism 50 .
- FIG. 4 is a schematic front view of a rolling mill 10 according to a second embodiment. As shown in FIG. 4 , differences from the first embodiment are as follows: the movably-supporting device 30 is provided on the upper side surface of the housing 11 ; and instead of the balance cylinder mechanism 50 , the first supporting-portion balance cylinder 60 a is provided for the first supporting portion 13 a and the second supporting-portion balance cylinder 60 b is provided for the second supporting portion 13 b.
- FIG. 5 is a schematic front view of the rolling mill 10 according to a third embodiment.
- the third embodiment differs from the second embodiment in that the fixed beam 70 is provided separately from the housing 11 and the movably-supporting device 30 is provided on the lower side surface of the fixed beam 70 instead of the housing 11 .
- the inclination of the first roll 14 a (difference in height between the first supporting portion 13 a side and the second supporting portion 13 b side) caused by the difference between the pressing loads on the first supporting portion 13 a side and the second supporting portion 13 b side (measurement values obtained from the first load cell 15 a and the second load cell 15 b ) is compensated for owing to the AGC function. Accordingly, the balance beam 51 (rail portion 30 b ) provided with the distance sensors 20 is always kept horizontal and the controller 40 can therefore correctly measure the roll deflections based on the detection values of the distance sensors 20 .
- the rail portion 30 b cannot be kept in a horizontal position with the use of the AGC function and therefore, the controller 40 cannot correctly measure the roll deflections based on the detection values of the distance sensors 20 .
- the controller 40 in the second embodiment and the third embodiment corrects the detection values of the distance sensors 20 by the amount of displacement caused by the vertical deformation of the housing 11 and controls the amount of depression of the hydraulic press cylinders 12 a and 12 b based on the corrected values.
- the distance sensors 20 are provided only above the first roll 14 a in the above-described embodiments, the present invention is not limited to this configuration.
- the distance sensors 20 may be provided only below the second roll 14 b or may be provided both above the first roll 14 a and below the second roll 14 b .
- the controller 40 may perform the calculation, described in connection with the above embodiments, with regard to the rolling areas AP of the second roll 14 b .
- the controller 40 may perform the calculation, described in connection with the above embodiments, with regard to both of the rolling areas AP of the first roll 14 and the rolling areas AP of the second roll 14 b , and, based on the results of the calculation (without the assumption that one of the rolls is bent symmetrically in the vertical direction with respect to the center line of the bar steel 1 in the vertical direction), the controller 40 may calculate the amount of depression of the first hydraulic press cylinder 12 a and the second hydraulic press cylinder 12 b for control.
- the rolling mill 10 includes the distance sensors 20 configured to measure the roll deflections in the rolling areas AP of at least one of the first roll 14 a and the second roll 14 b.
- the rolling mill is provided with the movably-supporting device 30 to move the distance sensors 20 in the longitudinal direction in the above-described embodiments
- the present invention is not limited to this configuration.
- the distance sensors 20 may be provided for all the plurality of rolling areas AP in an immovable manner.
- a configuration may be adopted such that at least one distance sensor 20 is provided for each of the plurality of rolling areas AP set at different positions.
- this configuration it is possible to omit the mechanism for moving the distance sensors 20 and therefore, it is possible to simplify the structure related to the distance sensors 20 .
- control performed in the rolling mill 10 using two distance sensors 20 has been described in connection with the above-described embodiments, the present invention is not limited to this configuration.
- three or more distance sensors 20 may be used to control the rolling mill 10 .
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Abstract
A rolling mill includes a roll pair, having first and second rolls, for rolling a bar steel, and first and second hydraulic cylinders for moving the first roll relative to the second roll, the first and second hydraulic cylinders being respectively connected to first and second supporting portions rotatably supporting the first roll at both ends thereof. A rolling area for rolling the bar steel, which is set as a partial continuous area in the longitudinal direction of the roll pair, is positioned so that distances from the rolling area to the supporting portions differ from each other, and the rolling mill includes: a distance sensor to measure a roll deflection in the rolling area of at least one of the rolls; and a controller to control the amount of depression of the hydraulic cylinders based on a detection value of the distance sensor.
Description
- The present invention relates to a rolling mill and a method of controlling the rolling mill.
- A rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, has already been widely available.
- There have been a problem of low accuracy in shape of the cross section of the bar steel, a problem of occurrence of a curve in the longitudinal direction of the bar steel, etc. when a rolling mill is used to roll the bar steel, in which a rolling area for rolling the bar steel, set as a partial continuous area in a longitudinal direction of the roll pair of the rolling mill, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other (the rolling mill, in which rolling is performed in the rolling area set as described above, will be referred to as the “offset rolling mill” for the sake of simplicity).
- For this reason, in a conventional offset rolling mill, the position of the rolling area is detected in advance of rolling and the vertical positions of both ends of the rolls are individually set based on the position information to perform control for improving the accuracy in shape of the cross section of the bar steel (see
Patent Document 1, for example). - [Patent Document 1] Japanese Examined Utility Model Publication No. H06-46567 (JP 06-46567 Y (1994))
- However, there still has been a problem of low accuracy in shape of the cross section of the bar steel in the case of conventional shape control methods used for offset rolling mills.
- The present invention has been made in consideration of such a problem and an object of the present invention is to achieve highly-accurate shape control in rolling a bar steel with the use of an offset rolling mill.
- In order to achieve the above object, a primary aspect of the present invention is
- a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, the rolling mill being characterized in that
- a rolling area for rolling the bar steel, which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other, and
- the rolling mill further includes:
- a distance sensor configured to measure a roll deflection in the rolling area of at least one of the first roll and the second roll; and
- a controller configured to control an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on a detection value of the distance sensor.
- Other features of the present invention will be clarified by this description and the attached drawings.
- According to the present invention, it is made possible to achieve highly-accurate shape control in rolling a bar steel with the use of an offset rolling mill.
-
FIG. 1 is a schematic front view of arolling mill 10 according to an embodiment; -
FIG. 2 is a diagram showing relation between acontroller 40 and other devices of therolling mill 10; -
FIG. 3 includes an upper drawing that is a diagram showing a state where rolling is performed with a roll pair sandwiching abar steel 1 in a bent state, and a lower drawing that is an explanatory diagram for explaining roll deflections of afirst roll 14 a; -
FIG. 4 is a schematic front view of arolling mill 10 according to a second embodiment; and -
FIG. 5 is a schematic front view of therolling mill 10 according to a third embodiment. - At least the followings are clarified by this description and the attached drawings.
- A rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, is characterized in that
- a rolling area for rolling the bar steel, which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other, and
- the rolling mill further includes:
- a distance sensor configured to measure a roll deflection in the rolling area of at least one of the first roll and the second roll; and
- a controller configured to control an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on a detection value of the distance sensor.
- According to the above-described rolling mill, it is made possible to achieve highly-accurate shape control in rolling a bar steel with the use of an offset rolling mill.
- In the above-described rolling mill, a plurality of the rolling areas may be set at different positions in the longitudinal direction of the roll pair.
- According to the above-described rolling mill, it is made possible to achieve highly-accurate shape control regardless of in which of the rolling areas the bar steel is rolled.
- In the above-described rolling mill, at least one distance sensor may be provided for each of the plurality of rolling areas set at the different positions.
- According to the above-described rolling mill, it is possible to omit mechanism for moving the distance sensors and therefore, it is possible to simplify the structure related to the distance sensors.
- The above-described rolling mill may further include a movably-supporting device that supports the distance sensor movably in the longitudinal direction.
- According to the above-described rolling mill, it is possible to reduce the number of distance sensors as compared to the case where the distance sensors are provided for every one of the plurality of rolling areas.
- In the above-described rolling mill, the movably-supporting device may include: a mounting portion, to which the distance sensor is fixed; a rail portion, with which the mounting portion slidably engages; and a driving device for moving the mounting portion along the rail portion.
- According to the above-described rolling mill, it is possible to realize a reliable movable support with the use of simple components.
- The above-described rolling mill may be configured to be able to measure the roll deflections in both end portions of the rolling area in the longitudinal direction.
- According to the above-described rolling mill, it is made possible to determine the thicknesses of both edge portions of the bar steel in the longitudinal direction based on the roll deflections in both end portions of the rolling area in the longitudinal direction, so that it is made possible to make these thicknesses of both edge portions of the bar steel in the longitudinal direction more even.
- In the above-described rolling mill, the controller may be configured to control the amount of depression of the first hydraulic press cylinder and the amount of depression of the second hydraulic press cylinder in real time while the bar steel is rolled.
- According to the above-described rolling mill, it is made possible to achieve more accurate shape control in rolling a bar steel with the use of an offset rolling mill.
- In the above-described rolling mill, each of the first roll and the second roll may be provided with a caliber in the rolling area.
- According to the above-described rolling mill, the present invention is more effective because, when rolling is performed with the use of a roll pair provided with the calibers, the rolling is usually, or often, performed with the use of an offset rolling mill.
- A method of controlling a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, is characterized by including:
- setting a rolling area for rolling the bar steel, which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other;
- measuring a roll deflection in the rolling area of at least one of the first roll and the second roll; and
- controlling an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on the roll deflection.
- The above-described method of controlling the rolling mill brings about the same operations and effects as those in the case of the above rolling mill.
- ===Rolling Mill 10 According to Embodiment===
- A rolling
mill 10 according to this embodiment is an apparatus for rolling abar steel 1 to be rolled and is used as an offset rolling mill. This offset rolling mill means the rollingmill 10 characterized by the position of thebar steel 1 during rolling, which will be described in detail later. Examples of thebar steel 1 include flat steel, section steel, steel rods, wires, rails, and the like, meaning steel material with a shape having a very large length as compared to the size of the cross-sectional area. In this embodiment, flat steel is rolled as thebar steel 1. -
FIG. 1 is a schematic front view of therolling mill 10 according to this embodiment. In the drawings of this embodiment, lateral direction (horizontal direction) on the sheet is defined as “longitudinal direction,” and the left (right) side on the sheet is referred to as “WS (DS)” or “left (right),” while vertical direction on the sheet is defined as “vertical direction,” and the upper (lower) side on the sheet is referred to as “upper (lower) side.”FIG. 2 is a diagram showing relation between acontroller 40 and other devices of therolling mill 10. - A
housing 11 of therolling mill 10 is shown inFIG. 1 . Disposed in the housing 11 (inside the housing 11) are a pair of rolls (afirst roll 14 a and asecond roll 14 b), supporting portions (a first supportingportion 13 a, a second supportingportion 13 b, and supporting portions for thesecond roll 14 b), hydraulic press cylinders (a firsthydraulic press cylinder 12 a and a secondhydraulic press cylinder 12 b), load cells (afirst load cell 15 a and asecond load cell 15 b),distance sensors 20, a movably-supportingdevice 30, and abalance cylinder mechanism 50, which are included in the rollingmill 10. - The roll pair is a pair of upper and lower flat rolls, the
first roll 14 a and thesecond roll 14 b. Thefirst roll 14 a and thesecond roll 14 b are the same in shape and each has a rolling portion with a larger diameter and shaft portions with a smaller diameter, the shaft portions being provided at both ends of the rolling portion in the longitudinal direction. The roll pair catches thebar steel 1 in the gap between thefirst roll 14 a provided on the upper side and thesecond roll 14 b provided on the lower side as shown inFIG. 1 , and is rotated for rolling by the rotation driven by a drivingportion 32 shown inFIG. 2 . In other words, the rollingmill 10 includes the roll pair of thefirst roll 14 a and thesecond roll 14 b for rolling thebar steel 1 to be rolled. - In this embodiment, a plurality of partial continuous areas, corresponding to rolling areas AP, are set in the longitudinal direction of the rolling portions of the roll pair as positions in the longitudinal direction of the roll pair, between which the
bar steel 1 is passed, and are stored in amemory unit 41 described later. In other words, in the rollingmill 10, a plurality of the rolling areas AP are set at different positions in the longitudinal direction of the roll pair. - The supporting portions support both ends of each of the rolls of the roll pair in a state where the roll pair are rotatable, so that the roll pair can be rotated by the rotation driven by the driving
portion 32. In this description, “both ends of the roll” supported by the supporting portions mean the positions that are symmetric with respect to a roll center line RC (the center line in the longitudinal direction of the roll pair), in other words, the shaft portions (that is, not the rolling portion). The WS shaft portion of thefirst roll 14 a is supported by the first supportingportion 13 a and the DS shaft portion thereof is supported by the second supportingportion 13 b. These supporting portions are connected to the hydraulic press cylinders with abalance beam 51 interposed therebetween, which will be described later. Both ends of thesecond roll 14 b are supported by the supporting portions for thesecond roll 14 b that are fixed to a lower surface of a housing 11 (lower surface of the inside of the housing 11). - The hydraulic press cylinders (the first
hydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b), which are devices for moving thefirst roll 14 a relative to thesecond roll 14 b, are fixed to an upper side surface of the housing 11 (upper side surface of the inside of the housing 11) with the load cells, described later, interposed therebetween. Specifically, the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b are respectively connected to the first supportingportion 13 a and the second supportingportion 13 b and cause thefirst roll 14 a to move relative to thesecond roll 14 b by moving the supporting portions, to which the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b are connected. In other words, the rollingmill 10 includes the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b for moving thefirst roll 14 a relative to thesecond roll 14 b, the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b being respectively connected to the first supportingportion 13 a and the second supportingportion 13 b that rotatably support thefirst roll 14 a at both ends of thefirst roll 14 a. - The load cells (the
first load cell 15 a and thesecond load cell 15 b), which are sensors for detecting the pressure applied to the supporting portions by the hydraulic press cylinders connected thereto, are interposed between thehousing 11 and the hydraulic press cylinders. Specifically, thefirst load cell 15 a is provided between an upper side surface (installation surface) of the firsthydraulic press cylinder 12 a and the upper side surface of thehousing 11, and thesecond load cell 15 b is provided between an upper side surface (installation surface) of the secondhydraulic press cylinder 12 b and the upper side surface of thehousing 11. The load cells continuously detect the pressure (reaction force to the pressure applied to the supporting portions by the hydraulic press cylinders connected thereto), at which the load cells are pressed between thehousing 11 and the hydraulic press cylinders, as pressure values, at which the hydraulic press cylinders apply the pressure to the connected supporting portions. The load cells immediately transmit the detection results to thecontroller 40. - The
controller 40 has an automatic gap control (AGC) function and can perform compensation, based on the pressure detected by the load cells, by the amount of vertical displacement of the first supportingportion 13 a and the second supportingportion 13 b, the displacement being caused by vertical elongation (vertical deformation) of thehousing 11. - The
controller 40 having received the pressure values detected by the load cells calculates the amount of vertical deformation of thehousing 11 and the amount of vertical deformation of bearings of the supporting portions (members for rotatably supporting thefirst roll 14 a), which are not shown, with the use of the detected pressure values. Thecontroller 40 then corrects the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b with the use of the calculated amounts of vertical deformation. Note that the deformation of the bearing is calculated based on a graph between load and radial displacement of the bearing and the detected pressure values. - The
distance sensors 20 are sensors for measuring the roll deflections, each detecting the distance between thedistance sensor 20 and the roll. The “roll deflection” herein means the difference between the vertical position of the roll that is measured by a detection value of thedistance sensor 20 in a state where the roll pair is not bent (hereinafter also referred to as the “zero-deflection state”) and the vertical position of the roll that is measured by the detection value of thedistance sensor 20 in a state where the roll pair is bent. - In this embodiment, the
distance sensors 20 are fixed to mountingportions 30 a of the movably-supportingdevice 30, which will be described later, provided above thefirst roll 14 a. Over one end portion and the other end portion, in the longitudinal direction, of the rolling area AP for thebar steel 1 to be rolled (both end portions of the rolling area AP), twodistance sensors 20, one over each end portion, are provided. Accordingly, thedistance sensors 20 detect the distances to thefirst roll 14 a in both end portions of the rolling area AP and transmit the detected distances to thecontroller 40. For example, eddy-current displacement sensors, laser distance sensors, or the like, can be used as thedistance sensors 20. - The movably-supporting
device 30 is provided on the lower side surface of thebalance beam 51, which is positioned above thefirst roll 14 a and will be described later, so as to be extended between both end portions, one end portion and the other end portion, of thefirst roll 14 a. The movably-supportingdevice 30 includes the mountingportions 30 a, to which thedistance sensors 20 are fixed, arail portion 30 b, with which the mountingportions 30 a slidably engage, and driving devices (not shown) for moving the mountingportions 30 a along therail portion 30 b. In other words, the movably-supportingdevice 30 is a device for moving thedistance sensors 20 between both end portions, one end portion and the other end portion, of thefirst roll 14 a above thefirst roll 14 a. Note that “both end portions of the roll” mean both end portions of the rolling portion of the roll (that is, not the shaft portions). One mountingportion 30 a and one driving device are provided for eachdistance sensor 20. A plurality of the mountingportions 30 a can slidably engage onerail portion 30 b. This means that the plurality of mountingportions 30 a (distance sensors 20) engaging with therail portion 30 b are moved along therail portion 30 b by the driving devices between the one end portion and the other end portion of the rolling portion of thefirst roll 14 a. In other words, the rollingmill 10 includes the movably-supportingdevice 30 supporting thedistance sensors 20 movably along the longitudinal direction. - The movably-supporting
device 30 has a position detection function of detecting positions of the mountingportions 30 a in the longitudinal direction and the position information obtained by the detection is transmitted to thecontroller 40. Thus, it is possible to move the mountingportions 30 a carrying thedistance sensors 20 along therail portion 30 b to the instructed positions in the longitudinal direction between the one end portion and the other end portion of the rolling portion by the driving devices as drivers according to instructions from thecontroller 40. - The
controller 40 shown inFIG. 2 is included in the rollingmill 10 and receives information transmitted from various devices as described above. Thecontroller 40 has thememory unit 41 that stores the information, and anarithmetic unit 42 that performs calculation with the use of the received information, the information stored in thememory unit 41, etc. Thecontroller 40 sends instructions to the various devices based on the results of calculation by thearithmetic unit 42, etc. In other words, thecontroller 40 controls the various devices included in the rollingmill 10 based on the various kinds of information. - The
balance cylinder mechanism 50 includes afirst balance cylinder 50 a, asecond balance cylinder 50 b, and thebalance beam 51. Thefirst balance cylinder 50 a and thesecond balance cylinder 50 b are fixed to the upper side surface of thehousing 11 so as to be positioned symmetrically with respect to the roll center line RC, and the vertically-movable cylinder portions of thefirst balance cylinder 50 a and thesecond balance cylinder 50 b are connected to thebalance beam 51. Thebalance beam 51 is provided so as to be extended from the first supportingportion 13 a to the second supportingportion 13 b in the longitudinal direction and is configured to, when rolling is not performed, raise the first supportingportion 13 a and the second supportingportion 13 b so as to maintain a gap between thefirst roll 14 a and thesecond roll 14 b. When the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b move the connected supporting portions, thebalance beam 51 is also moved accordingly. Thebalance beam 51 is also connected to thefirst balance cylinder 50 a and thesecond balance cylinder 50 b so that thebalance beam 51 can pivot about pivot axes extending along the direction perpendicular to the sheet ofFIG. 1 . - As described above, in the rolling
mill 10, the plurality of rolling areas AP are set at different positions in the longitudinal direction of the roll pair. As shown inFIG. 1 as an example, each rolling area AP according to this embodiment is set so that the center of the rolling area AP in the longitudinal direction does not coincide with the roll center line RC. In other words, each rolling area AP is set so that both end portions of the rolling area AP are positioned asymmetrically with respect to the roll center line RC. This means that the rolling area AP for rolling thebar steel 1, which is set in a partial continuous area in the longitudinal direction of the roll pair, is positioned so that the distance between the first supportingportion 13 a and the rolling area AP and the distance between the second supportingportion 13 b and the rolling area AP differ from each other because the first supportingportion 13 a and the second supportingportion 13 b are provided symmetrically with respect to the roll center line RC. - A method of controlling the offset rolling mill (the rolling
mill 10 shown inFIG. 1 that shows a state where thebar steel 1 is rolled at one of the set rolling areas AP) will be described below. - ===Control of the
Rolling Mill 10=== - Control of the rolling
mill 10 according to this embodiment will be described with reference toFIG. 1 , and upper and lower drawings ofFIG. 3 . - The upper drawing of
FIG. 3 is a diagram showing a state where rolling is performed with the roll pair sandwiching thebar steel 1 in a bent state. The lower drawing ofFIG. 3 is an explanatory diagram for explaining the roll deflections of thefirst roll 14 a. While the roll pair during ordinary rolling is not deflected so greatly as shown in the upper and lower drawings ofFIG. 3 , the deflections are exaggerated for ease of understanding. - As shown in the upper drawing of
FIG. 3 , in the roll pair during rolling according to this embodiment, thefirst roll 14 a is bent so that the central portion (at the roll center line RC) of thefirst roll 14 a is positioned upward and both ends thereof are positioned downward, and thesecond roll 14 b is bent so that the central portion of thesecond roll 14 b is positioned downward and both ends thereof are positioned upward. For this reason, when thebar steel 1 is rolled with the use of the rollingmill 10 as the offset rolling mill as show inFIG. 1 , thebar steel 1 having a cross-sectional shape conforming to the bent shape of the roll pair is produced, which results in the difference between thicknesses of both edge portions of thebar steel 1 in the longitudinal direction. - In this Embodiment, in order to improve accuracy in shape of the cross section of the
bar steel 1, control is performed so that the thickness of thebar steel 1 rolled by the offset rolling mill shown inFIG. 1 becomes a predetermined dimension and the thicknesses of both edge portions of thebar steel 1 in the longitudinal direction become equal to each other. Steps of the control will be described in order below. - A rolling area AP shown in
FIG. 1 is selected as the rolling area AP to be used from among the plurality of rolling areas AP set in the rollingmill 10. Thecontroller 40 of the rollingmill 10 then disposes, or moves, thedistance sensors 20 to the positions corresponding to both end portions, one end portion and the other end portion, of the selected rolling area AP in the longitudinal direction. In other words, the rollingmill 10 is configured to be able to measure the roll deflections in both end portions of the rolling area AP in the longitudinal direction. - The selection of the rolling area AP to be used may be performed manually, or may be performed, for example, based on the results of detection by a sensor for detecting the rolling area AP of the
bar steel 1, the sensor being provided on the upstream side of the roll pair in the travel direction of the bar steel 1 (direction perpendicular to the sheet inFIG. 1 ). - When the
distance sensors 20 have been moved to the positions corresponding to both end portions of the rolling area AP, thecontroller 40 detects the values from thedistance sensors 20 in “the state where the roll pair is not bent (zero-deflection state)” described above, and stores the values to thememory unit 41 in advance of rolling. - The
controller 40 then starts rolling thebar steel 1 in the rollingmill 10. During the rolling, twodistance sensors 20 positioned over a first detection point P1 and a second detection point P2 shown in the upper and lower drawings ofFIG. 3 (positioned over both end portions of the rolling area AP) detect the distances to thefirst roll 14 a and transmit the detected values to thecontroller 40. - The
controller 40 having received the detected values of the first detection point P1 and the second detection point P2 measures, or calculates, a first roll deflection X1 from the detected value of the first detection point P1 and a second roll deflection X2 from the detected value of the second detection point P2. The dashed straight line extending in the longitudinal direction shown in the lower drawing ofFIG. 3 is a straight line (hereinafter also referred to as the “reference line BL”) expressing the position of thefirst roll 14 a in a zero-deflection state. Specifically, the first roll deflection X1 and the second roll deflection X2 are values by which the detection values of thedistance sensors 20 received by thecontroller 40 during rolling differ from the detection values of thedistance sensors 20 obtained in the zero-deflection state. - The
controller 40 having measured the first roll deflection X1 and the second roll deflection X2 calculates the amount of depression (compensation amount) of the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b so that the thicknesses of both edge portions of thebar steel 1 in the longitudinal direction are equalized. - Specifically, the
arithmetic unit 42 calculates the inclination (corresponding to the inclination S1 between both end portions) between the first detection point P1 and the second detection point P2 in the longitudinal direction with respect to the reference line BL from the first roll deflection X1 and the second roll deflection X2 with the use of the following equation. -
Inclination S1 between both end portions=(First roll deflection X1−Second roll deflection X2)/(Second distance L2−First distance L1) - As shown in the lower drawing of
FIG. 3 , the first distance L1 is the distance between the first detection point P1 and the roll center line RC in the longitudinal direction, and the second distance L2 is the distance between the second detection point P2 and the roll center line RC. A supporting-portion distance L, which is used in an equation described later, is the distance between the first supportingportion 13 a and the roll center line RC in the longitudinal direction. These values are determined from the positions of the actually-used rolling areas in the longitudinal direction, the configuration of the rollingmill 10, etc., and are therefore stored in thememory unit 41 in advance. - The
arithmetic unit 42 having calculated the inclination S1 between both end portions calculates compensation values in the vertical direction for the first supportingportion 13 a and the second supportingportion 13 b with the use of the following equations. -
Compensation value for Firsthydraulic press cylinder 12a (First supportingportion 13a)=((First roll deflection X1+Second roll deflection X2)/2)−(Inclination S1 between both end portions×Supporting-portion distance L) -
Compensation value for Secondhydraulic press cylinder 12b (Second supporting portion 13b)=((First roll deflection X1+Second roll deflection X2)/2)+(Inclination S1 between both end portions×Supporting-portion distance L) - In these equations, the part, “(First roll deflection X1+Second roll deflection X2)/2,” is the average of the first roll deflection X1 and the second roll deflection X2 (hereinafter also referred to as the “average roll deflection”), and the part, “(Inclination S1 between both end portions×Supporting-portion distance L),” is the compensation value for the supporting portions that is used to make the inclination S1 between both end portions parallel to the reference line BL.
- The
controller 40 then causes the supporting portions connected to the respective hydraulic press cylinders to move in the vertical direction based on the calculated compensation values. Specifically, the amount of depression is increased by the average roll deflection and the first supportingportion 13 a and the second supportingportion 13 b are moved in the vertical direction so as to make the inclination S1 between both end portions parallel to the reference line BL. - Specifically, the compensation amount for the first
hydraulic press cylinder 12 a is the sum of the increase of the amount of depression (positive value) corresponding to the average roll deflection, which compensates for shortage of the amount of depression caused by deflection of the rolls, and the increase of the amount of depression (negative value) to make the inclination S1 between both end portions parallel to the reference line BL. When this sum is positive, the amount of depression of the firsthydraulic press cylinder 12 a is increased, so that the first supportingportion 13 a is additionally moved downward by the compensation amount. When this sum is negative, the amount of depression of the firsthydraulic press cylinder 12 a is reduced, so that the first supportingportion 13 a is moved upward by the compensation amount. - The compensation amount for the second
hydraulic press cylinder 12 b is the sum of the increase of the amount of depression (positive value) corresponding to the average roll deflection, which compensates for shortage of the amount of depression caused by deflection of the rolls, and the increase of the amount of depression (positive value) to make the inclination S1 between both end portions parallel to the reference line BL. This means that the amount of depression of the secondhydraulic press cylinder 12 b is increased, and therefore, the second supportingportion 13 b is additionally moved downward by the compensation amount. - In this way, control of the amount of depression of the first
hydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b, focusing on thefirst roll 14 a, is performed. - As shown in the upper drawing of
FIG. 3 , thesecond roll 14 b is also bent as in the case of thefirst roll 14 a, and therefore, it is also necessary to perform correction (control) of the hydraulic press cylinders, focusing on thesecond roll 14 b. For this reason, in this embodiment, it is assumed that thesecond roll 14 b is also bent similarly to thefirst roll 14 a. Specifically, it is assumed that the rolls are bent symmetrically in the vertical direction with respect to the center line of thebar steel 1 in the thickness direction (vertical direction). - However, since there is no equipment provided for moving the
second roll 14 b in the vertical direction, thesecond roll 14 b cannot be moved. For this reason, in this embodiment, thefirst roll 14 a is moved in the vertical direction by the sum of the amount corresponding to the deflection of thefirst roll 14 a and the amount corresponding to the deflection of thesecond roll 14 b (that is, twice of the amount corresponding to the deflection of thefirst roll 14 a). This makes it possible to perform control the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b, focusing on both of thefirst roll 14 a and thesecond roll 14 b. - By moving the
first roll 14 a in the vertical direction as described above, it is made possible to attain movement by the amount corresponding to the sum of the average roll deflection of thefirst roll 14 a and that of thesecond roll 14 b and to reduce the inclination in the rolling area (to make the inclinations of both rolls between both end portions parallel to the reference line BL). Specifically, thecontroller 40 controls the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b based on the detection values of thedistance sensors 20 so as to reduce the dimensional error of thebar steel 1 by compensating for shortage of the amount of depression caused by deflection of the rolls and to improve accuracy in shape of the cross section by reducing the inclination of thefirst roll 14 a between both end portions of the rolling area AP in the longitudinal direction set in thefirst roll 14 a and reducing the inclination of thesecond roll 14 b between both end portions of the rolling area AP in the longitudinal direction set in thesecond roll 14 b. - When the
controller 40 according to this embodiment receives the information on distance at the first detection point P1 and the second detection point P2 from thedistance sensors 20, thecontroller 40 immediately calculates the compensation amount at thearithmetic unit 42. When compensation is needed, thecontroller 40 controls the amount of depression of the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b and waits for the next transmission from thedistance sensors 20. Thedistance sensors 20 continuously detect the distance to the first detection point P1 and the distance to the second detection point P2 and immediately transmit the detection results to thecontroller 40. In other words, thecontroller 40 controls the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b in real time while thebar steel 1 is rolled. - ===Effectiveness of the
Rolling Mill 10 According to this Embodiment=== - As described above, the rolling
mill 10 according to this embodiment includes: the roll pair having thefirst roll 14 a and thesecond roll 14 b for rolling thebar steel 1 to be rolled; and the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b for moving thefirst roll 14 a relative to thesecond roll 14 b, the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b being respectively connected to the first supportingportion 13 a and the second supportingportion 13 b that rotatably support thefirst roll 14 a at both ends of thefirst roll 14 a. In the rollingmill 10, each of the rolling areas AP for rolling thebar steel 1, each of which is set as a partial continuous area in the longitudinal direction of the roll pair, is positioned so that the distance between the first supportingportion 13 a and the rolling area AP and the distance between the second supportingportion 13 b and the rolling area AP differ from each other. The rollingmill 10 further includes thedistance sensors 20 configured to measure the roll deflections at the rolling areas AP of thefirst roll 14 a, and thecontroller 40 configured to control the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b based on the detection values of thedistance sensors 20. Accordingly, it is made possible to achieve highly-accurate shape control in rolling thebar steel 1 with the use of the offset rolling mill. - When an offset rolling mill is used to roll the
bar steel 1, there have been a problem of low accuracy in shape of the cross section of thebar steel 1, a problem of occurrence of a curve in the longitudinal direction of thebar steel 1, etc. because shortage of the amount of depression and inclination in the rolling areas AP of the rolls occur due to deflection of the roll, which causes the occurrence of dimensional error of thebar steel 1 and unevenness in thickness between both edge portions of the rolledbar steel 1 in the longitudinal direction. - By contrast, the rolling
mill 10 according to this embodiment includes thedistance sensors 20 configured to measure the roll deflections at the rolling areas AP of thefirst roll 14 a, and thecontroller 40 configured to control the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b based on the detection values of thedistance sensors 20. By detecting deformation of thefirst roll 14 a with the use of thedistance sensors 20, it is possible to directly keep track of the deformation of the roll pair caused during rolling and measure the roll deflections in the rolling areas AP based on the deformation. Moreover, since thecontroller 40 controls the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b in accordance with the roll deflections, it is made possible to achieve highly-accurate shape control in rolling thebar steel 1 with the use of the offset rolling mill. - In this embodiment, the rolling
mill 10 is configured to be able to measure the roll deflections in both end portions of the rolling area AP in the longitudinal direction. Accordingly, by correcting the amount of depression of the hydraulic press cylinders based on the roll deflections in both end portions of the rolling area AP in the longitudinal direction, it is made possible to reduce the dimensional error of thebar steel 1 by compensating for shortage of the amount of depression caused by deflection of the rolls and to reduce the inclination of thefirst roll 14 a between both end portions of the rolling area AP in the longitudinal direction set in thefirst roll 14 a and the inclination of thesecond roll 14 b between both end portions of the rolling area AP in the longitudinal direction set in thesecond roll 14 b, which makes it possible to achieve highly-accurate shape control. - In this embodiment, the
controller 40 controls the amount of depression of the firsthydraulic press cylinder 12 a and the amount of depression of the secondhydraulic press cylinder 12 b in real time while thebar steel 1 is rolled. Since thecontroller 40 controls the amount of depression of the hydraulic press cylinders in real time, control is swiftly performed when it becomes necessary to control the amount of depression of the hydraulic press cylinders. This means that more accurate shape control is achieved in rolling thebar steel 1 with the use of the offset rolling mill. - In this embodiment, the rolling areas AP are set at different positions in the longitudinal direction of the roll pair and the present invention can be applied to all the rolling areas AP set at the different positions in the longitudinal direction of the roll pair. This means that it is possible to achieve highly-accurate shape control regardless in which of the rolling areas AP the
bar steel 1 is rolled. - In this embodiment, the rolling
mill 10 includes the movably-supportingdevice 30 that supports thedistance sensors 20 movably in the longitudinal direction. When a switch from a rolling area AP to another rolling area AP is made, the movably-supportingdevice 30 can move thedistance sensors 20 to the rolling area AP after the switch and the moveddistance sensors 20 can detect the values at the rolling area AP after switch. Accordingly, it is possible to reduce the number ofdistance sensors 20 as compared to the case where thedistance sensors 20 are provided for every one of the plurality of rolling areas AP. - In this embodiment, the movably-supporting
device 30 includes the mountingportions 30 a, to which thedistance sensors 20 are fixed, therail portion 30 b, with which the mountingportions 30 a slidably engage, and the driving devices for moving the mountingportions 30 a along therail portion 30 b. This means that a reliable movably-supportingdevice 30 can be realized with the use of simple components including the mountingportions 30 a, therail portion 30 b, and the driving devices. - While the rolling
mill 10 according to the present invention has been described with reference to the embodiment, the above-described embodiment is for ease of understanding of the present invention and the present invention is not limited to the above-described embodiment. Needless to say, modification and improvement can be made without departing from the spirit of the present invention, and the equivalent thereof is included in the present invention. - While the roll pair is made up of the flat rolls in the above-described embodiment, the present invention is not limited to this configuration. For example, the roll pair may be provided with calibers (grooves provided in the roll pair and formed in the same cross-sectional shape as that of the
bar steel 1, for forming the cross-sectional shape of thebar steel 1 by passing thebar steel 1 through the grooves; the grooves correspond to the rolling areas AP). Each of thefirst roll 14 a and thesecond roll 14 b may be provided with the caliber(s) in the rolling area(s) AP. - When rolling is performed with the use of a roll pair provided with the calibers, the rolling is usually, or often, performed with the use of an offset rolling mill and therefore, the present invention is more effective.
- While the
balance cylinder mechanism 50 is provided above thefirst roll 14 a and the movably-supportingdevice 30 is provided on the lower surface of thebalance beam 51 in the above-described embodiment, the present invention is not limited to this configuration. For example, as shown inFIG. 4 , the position of the movably-supportingdevice 30 may be changed and a first supporting-portion balance cylinder 60 a and a second supporting-portion balance cylinder 60 b may be provided instead of thebalance cylinder mechanism 50. -
FIG. 4 is a schematic front view of a rollingmill 10 according to a second embodiment. As shown inFIG. 4 , differences from the first embodiment are as follows: the movably-supportingdevice 30 is provided on the upper side surface of thehousing 11; and instead of thebalance cylinder mechanism 50, the first supporting-portion balance cylinder 60 a is provided for the first supportingportion 13 a and the second supporting-portion balance cylinder 60 b is provided for the second supportingportion 13 b. - A modification example of the second embodiment is a rolling mill, in which the installation position of the movably-supporting
device 30 is changed from thehousing 11 to a fixedbeam 70 as shown inFIG. 5 .FIG. 5 is a schematic front view of the rollingmill 10 according to a third embodiment. - As shown in
FIG. 5 , the third embodiment differs from the second embodiment in that the fixedbeam 70 is provided separately from thehousing 11 and the movably-supportingdevice 30 is provided on the lower side surface of the fixedbeam 70 instead of thehousing 11. - In the first embodiment, the inclination of the
first roll 14 a (difference in height between the first supportingportion 13 a side and the second supportingportion 13 b side) caused by the difference between the pressing loads on the first supportingportion 13 a side and the second supportingportion 13 b side (measurement values obtained from thefirst load cell 15 a and thesecond load cell 15 b) is compensated for owing to the AGC function. Accordingly, the balance beam 51 (rail portion 30 b) provided with thedistance sensors 20 is always kept horizontal and thecontroller 40 can therefore correctly measure the roll deflections based on the detection values of thedistance sensors 20. - However, in the second and third embodiments, the
rail portion 30 b cannot be kept in a horizontal position with the use of the AGC function and therefore, thecontroller 40 cannot correctly measure the roll deflections based on the detection values of thedistance sensors 20. For this reason, thecontroller 40 in the second embodiment and the third embodiment corrects the detection values of thedistance sensors 20 by the amount of displacement caused by the vertical deformation of thehousing 11 and controls the amount of depression of thehydraulic press cylinders - While the
distance sensors 20 are provided only above thefirst roll 14 a in the above-described embodiments, the present invention is not limited to this configuration. For example, thedistance sensors 20 may be provided only below thesecond roll 14 b or may be provided both above thefirst roll 14 a and below thesecond roll 14 b. However, it is preferable that thedistance sensors 20 be provided above thefirst roll 14 a so that the cooling water used during rolling is not splashed onto thedistance sensors 20. - When the
distance sensors 20 are provided only below thesecond roll 14 b, thecontroller 40 may perform the calculation, described in connection with the above embodiments, with regard to the rolling areas AP of thesecond roll 14 b. When thedistance sensors 20 are provided both above thefirst roll 14 a and below thesecond roll 14 b, thecontroller 40 may perform the calculation, described in connection with the above embodiments, with regard to both of the rolling areas AP of the first roll 14 and the rolling areas AP of thesecond roll 14 b, and, based on the results of the calculation (without the assumption that one of the rolls is bent symmetrically in the vertical direction with respect to the center line of thebar steel 1 in the vertical direction), thecontroller 40 may calculate the amount of depression of the firsthydraulic press cylinder 12 a and the secondhydraulic press cylinder 12 b for control. - In summary, it suffices that the rolling
mill 10 includes thedistance sensors 20 configured to measure the roll deflections in the rolling areas AP of at least one of thefirst roll 14 a and thesecond roll 14 b. - While the rolling mill is provided with the movably-supporting
device 30 to move thedistance sensors 20 in the longitudinal direction in the above-described embodiments, the present invention is not limited to this configuration. For example, thedistance sensors 20 may be provided for all the plurality of rolling areas AP in an immovable manner. In other words, a configuration may be adopted such that at least onedistance sensor 20 is provided for each of the plurality of rolling areas AP set at different positions. When this configuration is adopted, it is possible to omit the mechanism for moving thedistance sensors 20 and therefore, it is possible to simplify the structure related to thedistance sensors 20. - While control performed in the rolling
mill 10 using twodistance sensors 20 has been described in connection with the above-described embodiments, the present invention is not limited to this configuration. For example, three ormore distance sensors 20 may be used to control the rollingmill 10. -
- 1: bar steel
- 10: rolling mill
- 11: housing
- 12 a: first hydraulic press cylinder
- 12 b: second hydraulic press cylinder
- 13 a: first supporting portion
- 13 b: second supporting portion
- 14 a: first roll
- 14 b: second roll
- 15 a: first load cell
- 15 b: second load cell
- 20: distance sensor
- 30: movably-supporting device
- 30 a: mounting portion
- 30 b: rail portion
- 32: driving portion
- 40: controller
- 41: memory unit
- 42: arithmetic unit
- 50: balance cylinder mechanism
- 50 a: first balance cylinder
- 50 b: second balance cylinder
- 51: balance beam
- 60 a: first supporting-portion balance cylinder
- 60 b: second supporting-portion balance cylinder
- 70: fixed beam
- AP: rolling area
- P1: first detection portion
- P2: second detection portion
- S1: inclination between both end portions
- X1: first roll deflection
- X2: second roll deflection
- RC: roll center line
- BL: reference line
- L1: first distance
- L2: second distance
- L: supporting-portion distance
Claims (9)
1. A rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, wherein
a rolling area for rolling the bar steel, which is set as a partial continuous area in a longitudinal direction of the roll pair, is positioned so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other, and
the rolling mill further comprises:
a distance sensor configured to measure a roll deflection in the rolling area of at least one of the first roll and the second roll; and
a controller configured to control an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on a detection value of the distance sensor.
2. The rolling mill according to claim 1 , wherein
a plurality of the rolling areas are set at different positions in the longitudinal direction of the roll pair.
3. The rolling mill according to claim 2 , wherein
at least one distance sensor is provided for each of the plurality of rolling areas set at the different positions.
4. The rolling mill according to claim 1 , further comprising a movably-supporting device that supports the distance sensor movably in the longitudinal direction.
5. The rolling mill according to claim 4 , wherein
the movably-supporting device includes: a mounting portion, to which the distance sensor is fixed; a rail portion, with which the mounting portion slidably engages; and a driving device for moving the mounting portion along the rail portion.
6. The rolling mill according to claim 1 , wherein
the rolling mill is configured to be able to measure the roll deflections in both end portions of the rolling area in the longitudinal direction.
7. The rolling mill according to claim 1 , wherein
the controller is configured to control the amount of depression of the first hydraulic press cylinder and the amount of depression of the second hydraulic press cylinder in real time while the bar steel is rolled.
8. The rolling mill according to claim 1 , wherein
each of the first roll and the second roll is provided with a caliber in the rolling area.
9. A method of controlling a rolling mill that includes a roll pair, having a first roll and a second roll, for rolling a bar steel to be rolled, and a first hydraulic press cylinder and a second hydraulic press cylinder for moving the first roll relative to the second roll, the first hydraulic press cylinder and the second hydraulic press cylinder being respectively connected to a first supporting portion and a second supporting portion that rotatably support the first roll at both ends of the first roll, the method comprising:
positioning a rolling area for rolling the bar steel, which is set as a partial continuous area in a longitudinal direction of the roll pair, so that a distance between the first supporting portion and the rolling area and a distance between the second supporting portion and the rolling area differ from each other;
measuring a roll deflection in the rolling area of at least one of the first roll and the second roll; and
controlling an amount of depression of the first hydraulic press cylinder and an amount of depression of the second hydraulic press cylinder based on the roll deflection.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018059550A JP6832309B2 (en) | 2018-03-27 | 2018-03-27 | Rolling machine and control method of rolling machine |
JP2018-059550 | 2018-03-27 | ||
PCT/JP2019/001024 WO2019187508A1 (en) | 2018-03-27 | 2019-01-16 | Rolling mill and method for controlling rolling mill |
Publications (1)
Publication Number | Publication Date |
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US20210001388A1 true US20210001388A1 (en) | 2021-01-07 |
Family
ID=68059824
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/979,438 Abandoned US20210001388A1 (en) | 2018-03-27 | 2019-01-16 | Rolling mill and method of controlling the same |
Country Status (6)
Country | Link |
---|---|
US (1) | US20210001388A1 (en) |
JP (1) | JP6832309B2 (en) |
KR (1) | KR102364870B1 (en) |
CN (1) | CN111902223B (en) |
TW (1) | TWI701089B (en) |
WO (1) | WO2019187508A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112496029A (en) * | 2020-11-06 | 2021-03-16 | 福建三宝钢铁有限公司 | Controlled rolling and controlled cooling process for seawater corrosion resistant steel bar HRB400cE |
CN115815338A (en) * | 2023-01-10 | 2023-03-21 | 太原理工大学 | Hydraulic pressing system suitable for double-machine linkage ultra-large shaft wedge cross rolling mill |
Family Cites Families (14)
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JPS4974652A (en) * | 1972-11-21 | 1974-07-18 | ||
JPH04367306A (en) * | 1991-06-11 | 1992-12-18 | Nippon Steel Corp | Bend preventing method at the time of rolling continuously cast billet |
JPH0646567U (en) | 1992-12-09 | 1994-06-28 | カトー段ボール株式会社 | Partition |
US5613390A (en) * | 1993-11-24 | 1997-03-25 | Kawasaki Steel Corporation | Corner reduction device equipped with corner rolls, control device thereof, and method of rolling by using these devices |
CN1082851C (en) * | 1994-07-08 | 2002-04-17 | 石川岛播磨重工业株式会社 | Rolling method using both displacement and bending of roller, rolling machine and roller used for same |
DE19530424A1 (en) * | 1995-08-18 | 1997-02-20 | Schloemann Siemag Ag | Method for compensating forces on roll stands resulting from horizontal movements of the rolls |
JPH09295021A (en) * | 1996-04-30 | 1997-11-18 | Kawasaki Steel Corp | Device for deciding operational quantity of shape control of material to be rolled and method therefor |
JPH10166001A (en) * | 1996-12-06 | 1998-06-23 | Sumitomo Metal Ind Ltd | Method for rolling metallic strip |
KR200301280Y1 (en) * | 1998-12-19 | 2003-04-16 | 주식회사 포스코 | Rolling roll control device by detecting strip tension |
US7163047B2 (en) * | 2005-03-21 | 2007-01-16 | Nucor Corporation | Pinch roll apparatus and method for operating the same |
KR100711407B1 (en) * | 2005-12-26 | 2007-04-30 | 주식회사 포스코 | Method for adjusting the roll gap of single stand reversing mill |
JP5598549B2 (en) * | 2010-11-22 | 2014-10-01 | 東芝三菱電機産業システム株式会社 | Rolling mill control device |
JP5469143B2 (en) * | 2011-09-29 | 2014-04-09 | 株式会社日立製作所 | Rolling control device, rolling control method, and rolling control program |
CN104492813B (en) * | 2014-11-24 | 2017-03-22 | 西安捷锐精密冶金设备有限公司 | Integral arch type four-roller rolling mill |
-
2018
- 2018-03-27 JP JP2018059550A patent/JP6832309B2/en active Active
-
2019
- 2019-01-16 KR KR1020207027435A patent/KR102364870B1/en active IP Right Grant
- 2019-01-16 WO PCT/JP2019/001024 patent/WO2019187508A1/en active Application Filing
- 2019-01-16 US US16/979,438 patent/US20210001388A1/en not_active Abandoned
- 2019-01-16 CN CN201980021478.3A patent/CN111902223B/en active Active
- 2019-02-12 TW TW108104567A patent/TWI701089B/en active
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112496029A (en) * | 2020-11-06 | 2021-03-16 | 福建三宝钢铁有限公司 | Controlled rolling and controlled cooling process for seawater corrosion resistant steel bar HRB400cE |
CN115815338A (en) * | 2023-01-10 | 2023-03-21 | 太原理工大学 | Hydraulic pressing system suitable for double-machine linkage ultra-large shaft wedge cross rolling mill |
Also Published As
Publication number | Publication date |
---|---|
KR20200121877A (en) | 2020-10-26 |
TW201941840A (en) | 2019-11-01 |
WO2019187508A1 (en) | 2019-10-03 |
KR102364870B1 (en) | 2022-02-17 |
TWI701089B (en) | 2020-08-11 |
CN111902223B (en) | 2022-03-01 |
JP2019171394A (en) | 2019-10-10 |
JP6832309B2 (en) | 2021-02-24 |
CN111902223A (en) | 2020-11-06 |
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