Rolling machine and rolling method

Abstract

A control device 20 of a rolling machine 1 has: a first angle command section 20a that issues a command so as to adjust the angle between an upper pair and a lower pair, with the upper pair being in parallel and the lower pair being in parallel; a second angle command section 20b that issues a command that inclines work rolls 110A, 110B, with the angle of backup rolls 120A, 120B being maintained; and an axial position command section 20c that issues a command for shifting the work rolls 110A, 110B in the direction in which a thrust force acts, said force being the total thrust force that the work rolls 110A, 110B, which were inclined according to the command from the second angle command section 20b, receive from the backup rolls 120A, 120B and a rolled material S. On the basis of the commands by the first angle command section 20a, the second angle command section 20b, and the axial position command section 20c, the control device controls work-roll pressing devices 130, 130B, work-roll home-position control devices 140A,140B, and shift cylinders 115A,115B.

Description

[Technical field]

[0001] The present invention relates to a rolling mill and a rolling method. [Background technology]

[0002] As an example of a rolling mill that can appropriately control the plate crown and edge drop by a simple operation, Patent Document 1 describes a rolling mill in which the change in diameter is ax with respect to the coordinate X taken in the axial direction from the center of the barrel length. 5 -bx 2 It is described that the rolling mill comprises a pair of rolling rolls that are provided with a crowning given by -cx and that are arranged so as to be point symmetrical with respect to each other, a roll shift means that moves the rolling rolls relatively in the axial direction, and a roll cross means that inclines the rolling rolls in opposite directions to each other in a plane parallel to the rolled material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 63-264204 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need to meet the requirements for the accuracy of rolled products, especially the thickness accuracy in the width direction. width The main thickness anomalies in the width direction are plate crown, which is a bulge in the central part of the metal plate in the width direction, and edge drop, or edge up, which is a sudden change in plate thickness within a certain distance from both ends in the width direction.

[0005] One of the techniques for improving plate thickness accuracy is the technique described in the above-mentioned Patent Document 1. In Patent Document 1, the upper and lower curved work rolls that are crowned are shifted and then crossed, thereby suppressing plate crown and edge drop.

[0006] However, whether curved or uncurved, a slight inclination of the roll axes between adjacent rolls generates a thrust force in the axial direction, and resistance occurs when shifting in the axial direction, and the resistance becomes large during rolling, especially since a rolling load is applied during rolling. Therefore, improvements are required to realize the shifting of rolls during rolling.

[0007] An object of the present invention is to provide a rolling mill and a rolling method that can appropriately control the shape of a rolled material and that can more easily perform roll shift during rolling than in the past. [Means for solving the problem]

[0008] The present invention includes a plurality of means for solving the above-mentioned problems. One example of such a rolling mill includes a pair of upper and lower work rolls which have a curved contour with the diameter repeatedly increasing and decreasing from one end to the other in the axial direction and which are arranged so as to be point symmetrical with respect to each other, a pair of upper and lower backup rolls which respectively support the work rolls, a work roll horizontal direction actuator which moves the work rolls in the horizontal direction, a work roll axial direction actuator which moves the work rolls in the axial direction, and a control device which controls the angle adjustment by the work roll horizontal direction actuator and the axial position adjustment by the work roll axial direction actuator, the control device comprising: the roll roll horizontal direction actuator and the roll roll axial direction actuator are controlled based on commands from the first angle command unit, the second angle command unit, and the axial position command unit, which commands the work roll to move in a direction in which the total thrust force that the work roll tilted by the command of the second angle command unit will receive from the backup roll and the rolled material acts on the work roll tilted by the command of the second angle command unit; and the roll roll axial direction actuator is controlled based on commands from the first angle command unit, the second angle command unit, and the axial position command unit. Effect of the Invention

[0009] According to the present invention, it is possible to obtain a rolling mill and a rolling method that can appropriately control the shape of the rolled material and can easily perform roll shift during rolling compared to the conventional rolling method. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view showing a device configuration of a rolling mill according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a top view showing an outline of the configuration of equipment around an upper work roll of the rolling mill shown in FIG. [Diagram 3] FIG. 4 is a side view showing another example of the device configuration of the rolling mill according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the centers of rolls in a cross state in the rolling mill of the embodiment. [Diagram 5] FIG. 4 is a diagram for explaining each cross angle and each thrust force in the rolling mill of the embodiment. [Figure 6] FIG. 1 is a diagram showing the relationship between the cross angle and the thrust coefficient when the backup roll cross angle θb=0.5° in a rolling mill. [Figure 7] FIG. 1 is a diagram showing the relationship between the cross angle and the thrust coefficient when the backup roll cross angle θb=1.0° in a rolling mill. [Figure 8] FIG. 1 is a diagram showing the relationship between the cross angle and the thrust coefficient when the backup roll cross angle θb=1.5° in a rolling mill. [Figure 9] FIG. 1 is a diagram showing the relationship between the backup roll cross angle θb and θwbbase at which the thrust force becomes 0 in a rolling mill. [Figure 10] FIG. 2 is a diagram showing the state when the cross angle of the backup rolls is an arbitrary value (≠0) in the rolling mill of the embodiment, as viewed from the entry side in the rolling direction. [Figure 11] FIG. 2 is a diagram showing an outline of a response when a desired mechanical crown changes during rolling in the rolling mill of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of a rolling mill and a rolling method according to the present invention will be described with reference to Figs.

[0012] In the drawings used in this specification, the same or corresponding components are denoted by the same or similar reference numerals, and repeated description of these components may be omitted.

[0013] In the following explanation and drawings, the drive side (also referred to as "DS (Drive Side)") means the side on which the electric motors that drive the work rolls are installed when viewed from the front of the rolling mill, and the work side (also referred to as "WS (Work Side)") means the opposite side.

[0014] First, the overall configuration of the rolling mill will be described with reference to Figures 1 and 2. Figure 1 is a side view of the rolling mill of this embodiment, and Figure 2 is a top view showing an outline of the configuration of the equipment around the upper work roll of the rolling mill shown in Figure 1.

[0015] In Fig. 1, the rolling mill 1 is a four-stage cross roll rolling mill for rolling a rolled material S, and has a housing 100, a control device 20, and a hydraulic device 30. Note that the rolling mill is not limited to a one-stand rolling mill as shown in Fig. 1, and may be a rolling mill consisting of two or more stands.

[0016] The housing 100 is equipped with an upper and lower pair of work rolls, an upper work roll (also written as "WR") 110A and a lower work roll 110B, an upper backup roll (also written as "BUR") 120A that supports the upper work roll 110A, and a lower backup roll 120B that supports the lower work roll 110B. These backup rolls 120A, 120B are also arranged as an upper and lower pair, and are straight rolls with a linear profile in the axial direction.

[0017] As shown in FIG. 2, the upper work roll 110A and the lower work roll 110B of this embodiment have a diameter D W The rolls are curved rolls having a curved profile due to repeated increases and decreases in the roll width, and are arranged so as to be point symmetrical with respect to each other. Here, the position of the "point" in the "point symmetry" in the present invention may be the geometric center of the rolled material S in the width direction, or the geometric center when the rolling mill 1 is viewed from the rolling direction or the anti-rolling direction, and may be appropriately changed depending on the rolling conditions.

[0018] The pressing cylinder device 170 is a cylinder that applies a pressing force to the upper backup roll 120A, the upper work roll 110A, the lower work roll 110B, and the lower backup roll 120B by pressing the upper backup roll 120A. The pressing cylinder devices 170 are provided on the working side and the driving side of the housing 100, respectively.

[0019] The load cell 180 is provided at the bottom of the housing 100 as a rolling force measuring means for measuring the rolling force applied to the rolled material S by the upper work roll 110A and the lower work roll 110B, and outputs the measurement results to the control device 20.

[0020] The upper work roll bending cylinders 190A are provided on both the operation side and the drive side of the housing 100, on the inlet side and outlet side of the rolling material S. By appropriately driving the upper work roll bending cylinders 190A, a bending force is applied in the vertical direction to the bearing of the upper work roll 110A.

[0021] Similarly, the lower work roll bending cylinder 190B is provided on the inlet and outlet sides of the housing 100 for the rolled material S, on both the operating side and the driving side, and by driving it appropriately, applies a bending force in the vertical direction to the bearing of the lower work roll 110B.

[0022] The thrust force measuring devices 300A and 300B measure the thrust force acting on the shaft of the upper work roll 110A or the lower work roll 110B, respectively.

[0023] The hydraulic unit 30 is connected to the hydraulic cylinders of the work roll pressing devices 130A, 130B and work roll position control devices 140A, 140B, the hydraulic cylinders of the backup roll pressing devices 150A, 150B and backup roll position control devices 160A, 160B, the shift cylinders 115A, 115B, and also to the upper work roll bending cylinder 190A and the lower work roll bending cylinder 190B. Note that, for convenience of illustration, some of the communication lines and pressure oil supply lines have been omitted in FIG. 1. This also applies to the following drawings.

[0024] The control device 20 is a device composed of a computer and the like that controls the operation of each device in the rolling mill 1, and in this embodiment has a first angle command unit 20a, a second angle command unit 20b, an axial position command unit 20c, an angle acquisition unit 20d, etc.

[0025] This control device 20 receives as inputs the measurement result signals of the thrust forces acting on the shafts of the work rolls 110A, 110B measured by the thrust force measuring devices 300A, 300B, and measurement signals from the position measuring devices of the load cell 180, the work roll fixed position control devices 140A, 140B, and the backup roll fixed position control devices 160A, 160B.

[0026] The control device 20 controls the operation of the hydraulic device 30 based on commands from the first angle command unit 20a, the second angle command unit 20b, and the axial position command unit 20c, and controls the operation of angle adjustments by the work roll pressing devices 130A, 130B and work roll fixed position control devices 140A, 140B, and axial position adjustments by the shift cylinders 115A, 115B by supplying and discharging pressurized oil to the hydraulic cylinders of the work roll pressing devices 130A, 130B and work roll fixed position control devices 140A, 140B, and the shift cylinders 115A, 115B.

[0027] Similarly, the control device 20 controls the operation of the hydraulic device 30 and controls the operation of angle adjustment by the backup roll pressing devices 150A, 150B and the backup roll fixed position control devices 160A, 160B by supplying and discharging pressurized oil to the hydraulic cylinders of the backup roll pressing devices 150A, 150B and the backup roll fixed position control devices 160A, 160B.

[0028] Furthermore, the control device 20 controls the operation of the upper work roll bending cylinder 190A and the lower work roll bending cylinder 190B by supplying and discharging pressure oil to these cylinders.

[0029] Next, the configuration related to the upper work roll 110A and the lower work roll 110B will be described with reference to Figure 2. The upper backup roll 120A and the lower backup roll 120B have the same configuration except for the roll shape and the presence or absence of the shift cylinders 115A, 115B, and detailed description thereof is also omitted because it is almost the same.

[0030] As shown in FIG. 2, a housing 100 is provided on both ends of an upper work roll 110A of the rolling mill 1, and is set upright perpendicular to the roll axis of the upper work roll 110A.

[0031] The upper work roll 110A is rotatably supported by the housing 100 via a work side roll chock 112A and a drive side roll chock 112B.

[0032] The work roll pressing device 130A is disposed between the entry side of the housing 100 and the work side roll chock 112A and the drive side roll chock 112B on each of the work side and drive side, and presses the work side roll chock 112A and drive side roll chock 112B of the upper work roll 110A in the rolling direction with a predetermined pressure.

[0033] The work roll fixed position control device 140A is disposed between the exit side of the housing 100 and the work side roll chock 112A and the drive side roll chock 112B on each of the work side and drive side, and has a hydraulic cylinder (pressing device) that presses the work side roll chock 112A and the drive side roll chock 112B of the upper work roll 110A in the counter-rolling direction. The work roll fixed position control device 140A is equipped with a position measuring device (not shown) that measures the amount of movement of the hydraulic cylinder, and controls the position of the hydraulic cylinder.

[0034] Here, a fixed position control device refers to a device that measures the oil column position of a hydraulic cylinder serving as a pressing device using a position measuring device built into the device, and controls the oil column position until it reaches a specified oil column position.

[0035] The work roll pressing devices 130A, 130B, backup roll pressing devices 150A, 150B, and position control devices 140A, 140B, 160A, 160B function as angle adjusters that adjust the cross angles of the work rolls 110A, 110B and backup rolls 120A, 120B.

[0036] In addition, in Figures 1 and 2, an example is shown in which hydraulic devices are used as the work roll position control devices 140A, 140B, which are actuators for the cross device, and the backup roll position control devices 160A, 160B, but this is not limited to hydraulic devices, and devices of an electric or other configuration can also be used.

[0037] In addition, the work roll pressing device is arranged on the entry side of the rolled material S, and the work roll fixed position control device is arranged on the exit side, but the arrangement may be reversed, and the arrangement is not limited to the pattern shown in Figure 1, etc.

[0038] 1 and 2 show an example in which a pressing device is provided on the opposite side of the fixed position control device, but this is not essential and the system can be configured with only the fixed position control device. However, by installing the pressing device, it becomes possible to remove backlash between the roll chocks 112A, 112B and the fixed position control device, and the rolling direction positions of the roll chocks 112A, 112B can be stabilized.

[0039] The shift cylinder 115A is a cylinder that moves the upper work roll 110A in the axial direction, and the shift cylinder 115B is a cylinder that moves the lower work roll 110B in the axial direction.

[0040] Returning to FIG. 1, the backup roll pressing device 150A is disposed on each of the working side and the driving side, between the entry side of the housing 100 and the working side roll chock and the driving side roll chock (not shown), and presses the working side roll chock and the driving side roll chock of the upper backup roll 120A in the rolling direction with a predetermined pressure.

[0041] The backup roll position control device 160A is disposed between the exit side of the housing 100 and the work side roll chock and the drive side roll chock on each of the work side and the drive side, and has a hydraulic cylinder (pressing device) that presses the work side roll chock and the drive side roll chock of the upper backup roll 120A in the direction opposite to the rolling direction. The backup roll position control device 160A is equipped with a position measuring device (not shown) that measures the amount of movement of the hydraulic cylinder, and controls the position of the hydraulic cylinder. Note that, although the backup roll pressing device is disposed on the exit side of the rolling material S and the backup roll position control device is disposed on the entry side, they may be disposed in the opposite direction, and the arrangement is not limited to the pattern shown in FIG. 1 etc.

[0042] The rolling mill is not limited to the configuration shown in Fig. 1. For example, like a rolling mill 1A of this embodiment shown in Fig. 3, it may be an apparatus further provided with backup roll sliding devices 200A, 200B in addition to the rolling mill 1 of Fig. 1.

[0043] The backup roll sliding device 200A is provided at an upper portion of the upper backup roll 120A in the vertical direction, and the backup roll sliding device 200B is provided at a lower portion of the lower backup roll 120B in the vertical direction.

[0044] Next, a method for adjusting the cross angle during rolling by the rolling mill according to this embodiment will be described with reference to Fig. 4 onwards. Fig. 4 is a diagram for explaining the centers of the rolls in the crossed state, Fig. 5 is a diagram for explaining each cross angle and each thrust force, Figs. 6 to 8 are diagrams showing the relationship between the cross angle and the thrust coefficient, and Fig. 9 is a diagram showing the relationship between the backup roll cross angle θb and the θwb at which the thrust force becomes 0. base FIG. 10 is a view showing the state of the rolling mill of the embodiment as viewed from the entry side in the rolling direction. FIG. 11 is a view showing an outline of a case in which the desired mechanical crown changes during rolling.

[0045] In the cross state shown in Figures 4 and 5, the first angle command unit 20a of the control device 20 is a part that issues a command to adjust the angles of the upper pair and the lower pair with the upper work roll 110A and the upper backup roll 120A in a parallel state and the lower pair of the lower work roll 110B and the lower backup roll 120B in a parallel state. This first angle command unit 20a preferably executes the first angle control step. In Figure 4, the front side of the paper is the operating side and the back side of the paper is the driving side.

[0046] Preferably, the first angle command unit 20a of the control device 20 in this embodiment issues a command to tilt the upper pair of upper work roll 110A and upper backup roll 120A in parallel and the lower pair of lower work roll 110B and lower backup roll 120B in opposite directions in a horizontal plane, thereby performing a so-called pair cross.

[0047] Although the case of a pair cross mill in which the cross angle of the work rolls 110A, 110B is changed together with the backup rolls 120A, 120B will be described, the rolling mill and rolling method of the present invention can also be applied to a work roll cross mill in which the cross angle is set only for the work rolls 110A, 110B. In this case, the first angle command unit 20a issues a command to adjust the angle so that the upper pair of upper work roll 110A and upper backup roll 120A and the lower pair of lower work roll 110B and lower backup roll 120B are all kept parallel (i.e., angle 0).

[0048] 4 and 5, the second angle command unit 20b of the control device 20 is a part that issues a command to tilt the work rolls 110A, 110B while maintaining the angles of the backup rolls 120A, 120B. This second angle command unit 20b preferably executes the second angle control step.

[0049] The angle of the angle command value output by second angle command unit 20b is desirably smaller than the maximum angle of the angle command value output by first angle command unit 20a. That is, in this embodiment, it is desirably that the upper work roll 110A and the lower work roll 110B are crossed and then crossed even more minutely. For example, from the crossed pair state, it is desirably that the work rolls 110A, 110B are further crossed, preferably by a small amount (for example, 0.1° or less).

[0050] The axial position command unit 20c of the control device 20 is a part that issues a command to move the work rolls 110A, 110B in a direction in which the work rolls 110A, 110B inclined by the command of the second angle command unit 20b receive a total thrust force from the backup rolls 120A, 120B and the rolled material S. This axial position command unit 20c preferably executes the axial position control step.

[0051] It is desirable that the above-mentioned second angle command unit 20b and axial position command unit 20c issue commands at least during the rolling of the rolled material S. In other words, it is desirable that at least the second angle control step and the axial position control step are executed while the rolled material S is being rolled.

[0052] The angle acquisition unit 20d of the control device 20 acquires a zero thrust angle θwb formed by the work rolls 110A, 110B and the backup rolls 120A, 120B when the total thrust force applied to the work rolls 110A, 110B becomes zero. base This angle acquisition unit 20d preferably executes the angle acquisition step.

[0053] Such control has been discovered based on the following studies and findings.

[0054] For example, in a rolling facility having seven rolling mills, there is a requirement that the sixth and seventh rolling mills shift work rolls having a straight profile during rolling, and the fourth and fifth rolling mills shift work rolls having a curved profile during rolling.

[0055] However, the thrust forces between the rolled material and the work rolls and between the work rolls and the backup rolls are often generated randomly due to the inclination of the rolls relative to each other, so the shift speed may be extremely slow in one direction but extremely fast in the opposite direction, or vice versa.

[0056] In the sixth and seventh rolls, work roll shifting is mainly required for the purpose of dispersing wear. When shifting during idling at the gap of the rolled material, the rolling load is not applied and the shift resistance is small. However, in endless rolling, where rolling is continued without gaps in front of the rolling equipment, the rolling load is continuously applied. Therefore, the work roll shifting for dispersing wear during endless rolling is restricted in the shift direction, and the desired work roll shifting cannot be performed.

[0057] In addition, the rolling load of the 4th and 5th rolling stages is higher than that of the 6th and 7th rolling stages. Therefore, there is a restriction that there is a large restriction on shifting the work rolls during rolling.

[0058] When the thermal deformation of the work roll progresses, it is necessary to gradually increase the rolling load to compensate for the thermal deformation of the work roll and to maintain the thickness of the rolled material as the temperature of the rolled material gradually drops. However, increasing the rolling load bends the roll so as to make the rolled material convex, so it becomes necessary to correct the control of the plate crown / plate shape control in the concave direction.

[0059] In preparation for the case where adjustment by the work roll bending cylinder alone is no longer sufficient, it is desirable to perform shifting (flying shifting) of a work roll having a small cross or a curved profile during rolling.

[0060] In addition, there is a rolling process in which the plate thickness is changed during rolling, which is called a flying plate thickness change. Even when such a flying plate thickness change is performed, it is required to obtain the desired plate crown / plate shape even if the rolling conditions change, but if the adjustment capacity is insufficient with the work roll bending cylinder alone, it is desirable to perform a work roll microcross or a rolling shift of a work roll having a curved profile during rolling.

[0061] If the cross angle could be changed during rolling, it would be possible to accommodate larger changes in running conditions, but the mechanism required for changing the cross angle during rolling requires a backup roll sliding device having an expensive, large flat bearing portion. In contrast, a rolling mill having both pair cross and work roll shift functions is equipped with a shift device in the first place, so even if it is not equipped with the backup roll sliding device, if it becomes possible to shift a work roll having a curved profile during rolling, a considerable range of control can be realized at a relatively low cost and with a simple structure.

[0062] Here, the total of the thrust force and frictional resistance acting on the work roll when shifting the work roll during rolling is required as the shift force. The frictional resistance includes the frictional resistance of the offset force component of the rolling load, the frictional resistance of the work roll bending cylinder, and the resistance of the drive spindle extension part.

[0063] When a thrust force acts in the same direction as the shift direction, shift force = frictional resistance - thrust force, and when a thrust force acts in the opposite direction to the shift direction, shift force = frictional resistance + thrust force. Therefore, adjusting the direction of the thrust force is important in reducing the shift force.

[0064] If the rolls in contact with each other are inclined, axial slippage occurs between the rolls during rotation, generating a thrust force. Also, when one roll is moved in the axial direction, axial slippage occurs relative to the other roll, and a thrust force acts at that time. The thrust force generated when shifting the rolls in the axial direction tends to increase as the shift speed increases, so when the required shift force is large (shift force = frictional resistance + thrust force), the shift speed may slow down significantly or, in some cases, the rolls may not shift at all. In other words, by changing the inclination of the rolls in contact with each other to reduce the thrust force or to change the direction of the thrust force, it is possible to obtain the shift speed that is actually required.

[0065] Figure 6 shows the thrust coefficient μ when the backup roll cross angle θb is 0.5°. sw、 μ wb、 μ total The figures show the results of calculations. When the cross angle is between 0 and 0.5°, the work roll and backup roll cross together, and when the backup roll cross angle θb is 0.5°, the work roll angle is increased while θb is maintained. From Figure 6, the thrust coefficients are calculated as follows: thrust force Ft sw Ft sw =μ sw ×P, and in the case of a force in the driving direction as shown in Fig. 5, μ swThe thrust force acting on the work roll from the backup roll is Ft wb Ft wb =μ wb ×P, and μ in the case of a force in the operating direction as shown in Fig. 5 wb The total thrust force acting on the work rolls Ft total Ft total =Ft sw +Ft wb =μ total × P, and when the work roll cross angle θsw is 0.5144°, Ft total is approximately 0. At this time, the work roll minute cross angle θwb is θwb = θsw - θb = 0.0144°.

[0066] Figure 7 shows the thrust coefficients μ when the backup roll cross angle θb is 1.0°. sw、 μ wb、 μ total As in Fig. 6, the work roll and backup roll cross together from 0 to 1.0° cross angle, and when the backup roll cross angle θb is 1.0°, the work roll angle is increased while θb is maintained. From Fig. 7, when the work roll cross angle θsw is 1.0256°, Ft total is approximately 0, and at this time, the work roll minute cross angle θwb is θwb = θsw - θb = 0.0256°.

[0067] Figure 8 shows the calculation results when the backup roll cross angle θb is 1.5°. As in Figures 6 and 7, Figure 8 shows that when the work roll cross angle θsw is 1.5350°, Ft total is approximately 0, and the work roll minute cross angle θwb at this time is θwb = θsw - θb = 0.0350°.

[0068] As shown in these Figs. 6 to 8, the thrust coefficient μ swThe absolute value of increases with an increase in the work roll cross angle θsw. Compared to the increasing trend of the absolute value, when the work roll angle is increased while θb is maintained, the thrust coefficient μ wb The degree of increase in the absolute value of μ is quite large, and a small change in the work roll cross angle total =μ sw +μ wb = close to 0.

[0069] Figure 9 shows the relationship between the backup roll cross angle θb and the thrust force at 0 θwb in a rolling mill. base 6, 7, and 8 show the relationship between Ft total The vertical axis of FIG. 9 shows the work roll minute cross angle θwb at which the thrust force is almost zero. This is called the zero thrust force angle θwb. base And, for any θb, the work roll minute cross angle θwb is the angle θwb where the thrust force is zero. base When the value of Ft total =Ft sw +Ft wb >0, and the total thrust force is in the direction of the operating side. Therefore, in this case, it is easy to shift in the direction of the operating side.

[0070] In addition, the work roll minute cross angle θwb is set to 0 thrust angle θwb base When it is made larger than this, the work roll cross angle θsw is increased, which acts to change the gap distribution between the upper work roll 110A and the lower work roll 110B (hereinafter also referred to as "mechanical crown") in the concave direction.

[0071] Here, the gap distribution (mechanical crown) will be explained. In this specification, the "gap distribution (mechanical crown)" refers to the difference in the gap between the upper and lower work rolls at the center of the roll and the end of the roll. The mechanical crown adjustment amount refers to the amount of change in mechanical crown from the reference mechanical crown to obtain a desired mechanical crown in the rolling state, when the mechanical crown in an arbitrary state is taken as the reference mechanical crown.

[0072] Specifically, when the gap between the upper and lower work rolls at the center of the roll is represented as Hc and the gap between the upper and lower work rolls at the end of the roll is represented as He, the mechanical crown Cce is represented as Cce=He-Hc. In addition, when the reference mechanical crown is represented as Cce1 and the desired mechanical crown is represented as Cce2, the mechanical crown adjustment amount ΔCce can be represented as ΔCce=Cce2-Cce1.

[0073] Here, the roll end refers to, for example, a roll position corresponding to the width end of the maximum width of the rolled material, or a roll position corresponding to the vicinity of the width end of the maximum width, and is appropriately selected as the evaluation position.

[0074] From this, it can be seen that by adjusting the mechanical crown to change in the concave direction when the work roll having a curved contour and the shift are shifted to WS, the plate shape adjustment by the work roll micro-cross can be made to be the same as the plate shape adjustment made when the work roll having a curved contour is shifted in the direction that makes it easier to shift due to the work roll micro-cross.

[0075] In this way, the angle of the work roll having a curved profile is adjusted in two stages, preferably with a small cross in the second stage, and then the work roll is shifted in the direction in which the total thrust force that the work roll receives from the backup roll and the rolled material acts.

[0076] Next, a preferred detailed method for adjusting the cross angle during rolling by the rolling mill according to this embodiment will be described with reference to Fig. 10. Note that Fig. 10 shows a case where the upper work roll 110A is crossed so that its drive side is in the front (the exit side in the rolling direction), but the upper work roll 110A may be crossed so that its operating side is in the front. In that case, the orientations of the upper work roll 110A and the lower work roll 110B are reversed left to right.

[0077] FIG. 10 shows adjustment from the desired timing at which the mechanical crown between the upper work roll 110A and the lower work roll 110B is flat at an arbitrary backup roll cross angle θb at a certain timing during rolling.

[0078] As shown in FIG. 10(b), when the work roll minute cross angle θwb is zero thrust angle θwb base If it matches Ft total =Ft sw +Ft wb = 0, the total thrust force is 0. In this case, the thrust force acting on the work roll is 0. At this time, the mechanical crown is in a flat state.

[0079] In addition, as shown in FIG. 10(a), the work roll minute cross angle θwb is the thrust force zero angle θwb base When it is larger, Ft total =Ft sw +Ft wb >0, the total thrust force is in the direction of the operating side. In this case, it is easy to shift the work roll toward the operating side. Shifting the work roll toward the operating side acts to change the mechanical crown to a concave direction.

[0080] Therefore, when the second angle command unit 20b corrects the distribution of the gap between the upper work roll 110A and the lower work roll 110B in the axial direction in a concave direction, the work roll minute cross angle θwb inclined by the second angle command unit 20b is set to the zero thrust angle θwb obtained by the angle acquisition unit 20d. base The command shall be given to make it larger.

[0081] In addition, the axial position command unit 20c is configured to determine the diameter of the upper work roll 110A that is in contact with the rolling material S at the portion with the largest diameter (diameter D w1 In other words, the command is issued so that the part of the upper work roll 110A with the smallest diameter (the part with the diameter D in FIG. 2) approaches the part of the lower work roll 110B with the largest diameter. w2 The command is to separate the portion (the narrowest diameter portion) of the lower work roll 110B from the portion of the lower work roll 110B that has the narrowest diameter.

[0082] Furthermore, as shown in FIG. 10(c), when the work roll minute cross angle θwb is the thrust force zero angle θwb base When it is smaller, Ft total =Ft sw +Ft wb <0, the total thrust force is in the direction of the driving side. In this case, it is easier to shift in the direction of the driving side.

[0083] Therefore, when the gap distribution between the upper work roll 110A and the lower work roll 110B in the axial direction is corrected to a convex shape direction, the second angle command unit 20b is set to a value equal to the zero thrust force angle θwb obtained by the angle acquisition unit 20d. base The command shall be issued so that the

[0084] In addition, the axial position command unit 20c determines the diameter of the upper work roll 110A that comes into contact with the rolling material S at the thickest part (diameter D w1 In other words, the command is issued to move the thinnest diameter part of the upper work roll 110A (diameter D w2 A command is issued so that the diameter of the lower work roll 110B approaches the diameter of the lower work roll 110B at its narrowest point.

[0085] By making these adjustments, the strip shape adjustment made by the work roll micro-cross can be made to be the same as the strip shape adjustment made when the work rolls 110A, 110B, which have curved contours in a direction that makes it easier to shift them due to the work roll micro-cross, are shifted.

[0086] Next, an adjustment from the timing at which an arbitrary backup roll cross angle θb=0 at a certain timing during rolling and the desired mechanical crown between the upper work roll 110A and the lower work roll 110B is flat will be described.

[0087] Work roll minute cross angle θwb is thrust force 0 angle θwb base If it matches Ft total =Ft sw +Ft wb = 0, the total thrust force is 0. In this case, the thrust force acting on the roll is 0. At this time, the mechanical crown is in a flat state.

[0088] Work roll minute cross angle θwb is thrust force 0 angle θwb base (=0), Ft total =Ft sw +Ft wb >0, the total thrust force is in the direction of the operation side. In this case, it is easy to shift to the operation side. Therefore, the part of the upper work roll 110A that comes into contact with the rolling material S with the thickest diameter (diameter D w1 When θb is 0°, θwb is the same as the work roll cross angle θsw, and when θwb is θwb base When it is greater than (=0), the mechanical crown is changed in a concave direction. This makes it possible to make both the plate shape adjustment due to the minute cross of the work rolls and the plate shape adjustment made when the work rolls 110A, 110B, which have curved contours in a direction that makes it easier to shift due to the minute cross of the work rolls, be adjustments in the same concave direction.

[0089] Work roll minute cross angle θwb is thrust force 0 angle θwb base When it is smaller, Ft total =Ft sw +Ft wb<0, the total thrust force is in the direction of the driving side. In this case, it is easy to shift to the driving side. Therefore, the part of the upper work roll 110A that comes into contact with the rolling material S with the thickest diameter (diameter D w1 When θb is 0°, θwb is the same as the work roll cross angle θsw, and when θwb is θwb base (=0), the strip shape adjustment changes the mechanical crown in a concave direction, whereas the strip shape adjustment made when the work rolls 110A, 110B, which have curved contours in a direction that makes it easier to shift due to the minute cross of the work rolls, are shifted in a convex direction, and the two shape adjustments are in opposite directions. On the other hand, when θb is 0°, θwb is originally a very small value (at most about 0.1°), and therefore θsw, which has the same value as θwb, is also very small, so that the strip shape change in the concave direction caused by θsw is an extremely small value compared to the strip shape change in the convex direction obtained by shifting the rolls in a direction that makes it easier to shift, and therefore the strip shape adjustment in the convex direction by shifting can be effectively achieved.

[0090] Next, the effects of this embodiment will be described.

[0091] The control device 20 of the rolling mills 1, 1A of this embodiment described above includes a first angle command unit 20a that issues commands to adjust the angles of the upper pair and the lower pair while keeping the upper pair of the upper work roll 110A and the upper backup roll 120A in a parallel state and the lower pair of the lower work roll 110B and the lower backup roll 120B in a parallel state, a second angle command unit 20b that issues commands to tilt the work rolls 110A, 110B while maintaining the angles of the backup rolls 120A, 120B, and a second angle command unit 20c that issues commands to tilt the work rolls 110A, 110B while maintaining the angles of the backup rolls 120A, 120B. The system has an axial position command unit 20c which issues a command to move the work rolls 110A, 110B in the direction in which the total thrust force that the work rolls 110A, 110B receive from the backup rolls 120A, 120B and the rolled material S, which have been tilted by command, acts, and controls the work roll pressing devices 130A, 130B, work roll fixed position control devices 140A, 140B, and shift cylinders 115A, 115B based on the commands of the first angle command unit 20a, the second angle command unit 20b, and the axial position command unit 20c.

[0092] As shown in FIG. 11, the desired amount of mechanical crown adjustment may change during rolling.

[0093] More specifically, at the timing (a) in FIG. 11, when the amount of mechanical crown adjustment changes, the upper work roll bending cylinder 190A and the lower work roll bending cylinder 190B are adjusted to accommodate the change in the amount of mechanical crown adjustment.

[0094] Then, at the timing shown in FIG. 11(b), minute work roll cross adjustment is started to aim for the target value of the work roll bender force, and the work roll bender force is adjusted to the target value while maintaining the mechanical crown adjustment amount.

[0095] At the timing of (c) in Fig. 11, the work roll bender force reaches the target value due to the work roll minute cross adjustment carried out from the timing of (b) onwards, and the adjustment is almost complete, but at this time the work roll minute cross adjustment has been almost used up. In other words, if the absolute value of the work roll minute cross angle θwb is increased any further, the thrust bearings and roll necks of the work rolls 110A, 110B will not be able to withstand it, and there is no other way to deal with this situation.

[0096] Thereafter, at the timing (d) in FIG. 11, when the amount of mechanical crown adjustment changes, the upper work roll bending cylinder 190A and the lower work roll bending cylinder 190B are adjusted to accommodate the change in the amount of mechanical crown adjustment.

[0097] At the timing of (e) in Fig. 11, the work roll minute cross adjustment is in a state where it cannot be moved any further, so the shift adjustment of the work rolls 110A, 110B having curved contours is started to aim for the target value of the work roll bender force, and the work roll bender force is adjusted to the target value while maintaining the mechanical crown adjustment amount. At that time, the work roll minute cross amount is in a direction in which the work rolls 110A, 110B having curved contours can be easily shifted, so shifting is possible.

[0098] At the timing (f) in FIG. 11, the target value of the work roll bender force is reached through the shift adjustment of the work rolls 110A, 110B having curved contours, and the adjustment is almost completed.

[0099] In this way, the thrust force generated in the work rolls 110A, 110B by shape control through the first angle adjustment is appropriately corrected by adjusting the second angle before shifting, so that the work rolls 110A, 110B can be shifted without applying a large shift force, making roll shifting during rolling easier to perform than in the past and enabling appropriate control of the shape of the rolled material S.

[0100] In addition, the control device 20 calculates a zero thrust angle θwb between the work rolls 110A, 110B and the backup rolls 120A, 120B when the total thrust force becomes zero. base When the gap distribution in the axial direction of the upper work roll 110A and the lower work roll 110B is corrected to a concave shape direction, the second angle command unit 20b determines whether the angle between the work rolls 110A, 110B inclined by the second angle command unit 20b and the backup rolls 120A, 120B is θwb, and the angle θwb is the zero thrust angle θwb obtained by the angle command unit 20d. base The axial position command unit 20c issues a command to bring the thickest parts of the upper work roll 110A and the lower work roll 110B that contact the rolled material S closer to each other, so that the mechanical crown is controlled to be in the concave shape direction by the angle adjustment based on the first angle command. baseと By moving the work rolls so that the mechanical crown is shifted in a concave direction, the gap distribution can be changed to a larger concave shape, and the shape control range can be expanded.

[0101] Furthermore, in the case where the gap distribution between the upper work roll 110A and the lower work roll 110B in the axial direction is corrected to a convex shape direction, when the angle formed between the work rolls 110A, 110B inclined by the second angle command unit 20b and the backup rolls 120A, 120B is set to θwb, θwb is set to the zero thrust force angle θwb obtained by the angle acquisition unit 20d. baseSince the axial position command unit 20c issues a command to make the diameter of the upper work roll 110A and the lower work roll 110B in contact with the rolled material S smaller than the diameter of the upper work roll 110A, the axial position command unit 20c issues a command to separate the thickest parts of the upper work roll 110A and the lower work roll 110B, which are in contact with the rolled material S, so that the adjustment can be made in the convex shape direction, the tendency of the change in the width direction roll gap distribution caused by the micro cross and the tendency of the change in the width direction roll gap distribution caused by the shift can be matched, and a wider mechanical crown adjustment can be made. For example, when the adjustment of the plate crown is insufficient with only the upper work roll bending cylinder 190A and the lower work roll bending cylinder 190B in the bar being rolled, both the micro cross function and the shift function of the work rolls having a curved contour can be used, so that it can be used for a wider plate crown adjustment.

[0102] The system also includes backup roll pressing devices 150A, 150B for moving backup rolls 120A, 120B horizontally, and backup roll fixed position control devices 160A, 160B, and the control device controls the angle adjustments made by the backup roll pressing devices 150A, 150B and backup roll fixed position control devices 160A, 160B. The first angle command unit 20a issues a command to tilt the upper pair and the lower pair in opposite directions to each other in the horizontal plane, with the upper pair of upper work roll 110A and upper backup roll 120A parallel, and the lower pair of lower work roll 110B and lower backup roll 120B parallel. This makes it possible to change θsw significantly and further expand the shape control range.

[0103] Furthermore, at least the second angle command unit 20b and the axial position command unit 20c issue commands during rolling of the rolled material S, making it possible to operate in a way that easily follows changes in the required amount of mechanical crown during rolling.

[0104] <Other> The present invention is not limited to the above-mentioned embodiment, and various modifications and applications are possible. The above-mentioned embodiment has been described in detail to explain the present invention in an easily understandable manner, and the present invention is not necessarily limited to having all of the described configurations.

[0105] For example, in the above embodiment, the hot rolling mill and the hot rolling method are described, but the rolling mill and the rolling method of the present invention are also applicable to a cold rolling mill and a cold rolling method. [Explanation of symbols]

[0106] 1,1A...Rolling mill 20...Control device 20a...1st angle command section 20b…Second angle command section 20c...Axial position command section 20d…Angle acquisition section 30...Hydraulic system 100…Housing 110A...Upper work roll 110B…Lower work roll 112A...Work side roll chock 112B...Drive side roll chock 115A, 115B...Shift cylinder 120A…Upper backup roll 120B…Lower backup roll 130A, 130B...Work roll pressing device 140A, 140B... Work roll fixed position control device 150A, 150B...Backup roll pressing device 160A, 160B...Back-up roll position control device 170...Pressure cylinder device 180...Load cell 190A...Upper work roll bending cylinder 190B…Lower work roll bending cylinder 200A, 200B...Backup roll sliding device 300A, 300B...Thrust force measuring device

Claims

1. a pair of upper and lower work rolls each having a curved contour with the diameter repeatedly increasing and decreasing from one end to the other end in the axial direction, the pair being arranged so as to be point symmetric with respect to each other; A pair of upper and lower backup rolls each supporting the work roll; a work roll horizontal direction actuator that moves the work roll in a horizontal direction; a work roll axial direction actuator that moves the work roll in the axial direction; a control device for controlling the angle adjustment by the work roll horizontal direction actuator and the axial position adjustment by the work roll axial direction actuator, The control device includes: a first angle command unit that issues a command to adjust the angles of an upper pair of upper work rolls and upper backup rolls and a lower pair of lower work rolls and lower backup rolls while keeping the upper pair of upper work rolls and upper backup rolls parallel and keeping the lower pair of lower work rolls and lower backup rolls parallel; a second angle command unit that issues a command to tilt the work roll while maintaining the angle of the backup roll; an axial position command unit that issues a command to move the work roll in a direction in which a total thrust force that the work roll receives from the backup roll and the rolled material acts on the work roll inclined by a command from the second angle command unit, The work roll horizontal direction actuator and the work roll axial direction actuator are controlled based on commands from the first angle command unit, the second angle command unit, and the axial position command unit. A rolling mill characterized by:

2. 2. The rolling mill according to claim 1, The control device determines an angle θ between the work roll and the backup roll when the total thrust force becomes 0. ｂａｓｅ The angle acquisition unit further acquires an angle When the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected to a concave shape direction, the second angle command unit determines whether the angle between the work roll inclined by the second angle command unit and the backup roll is θwb or not, and the angle between the work roll inclined by the second angle command unit and the backup roll is θwb. ｂａｓｅ Command it to get bigger, The axial position command unit issues a command to bring the thickest diameter portions of the upper work roll and the lower work roll, which are in contact with the rolled material, closer to each other. A rolling mill characterized by:

3. 2. The rolling mill according to claim 1, The control device determines an angle θ between the work roll and the backup roll when the total thrust force becomes 0. ｂａｓｅ The angle acquisition unit further acquires an angle When the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected to a convex shape direction, the second angle command unit determines whether the angle between the work roll inclined by the second angle command unit and the backup roll is θwb or not, and the angle is the angle obtained by the angle acquisition unit. ｂａｓｅ Give it a command to become smaller, The axial position command unit issues a command to separate the thickest diameter portions of the upper work roll and the lower work roll that come into contact with the rolled material. A rolling mill characterized by:

4. 3. The rolling mill according to claim 2, When the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected to a convex shape direction, the second angle command unit determines whether the angle between the work roll inclined by the second angle command unit and the backup roll is θwb or not, and the angle is the angle obtained by the angle acquisition unit. ｂａｓｅ Give it a command to become smaller, The axial position command unit issues a command to separate the thickest diameter portions of the upper work roll and the lower work roll that come into contact with the rolled material. A rolling mill characterized by:

5. In the rolling mill according to any one of claims 1 to 4, A backup roll horizontal actuator for moving the backup roll in a horizontal direction is further provided. The control device controls the angle adjustment by the backup roll horizontal actuator, The first angle command unit issues a command to tilt the upper pair of upper work rolls and upper backup rolls in directions opposite to each other in a horizontal plane while keeping the upper pair of upper work rolls and upper backup rolls parallel and keeping the lower pair of lower work rolls and lower backup rolls parallel. A rolling mill characterized by:

6. The rolling mill according to any one of claims 1 to 5, At least the second angle command unit and the axial position command unit issue commands during rolling of the rolled material. A rolling mill characterized by:

7. The rolling mill according to any one of claims 1 to 6, The angle of the angle command value output by the second angle command unit is smaller than the maximum value of the angle of the angle command value output by the first angle command unit. A rolling mill characterized by:

8. A method for rolling a rolled material using a rolling mill comprising a pair of upper and lower work rolls which have a curved contour with the diameter repeatedly increasing and decreasing from one end to the other end in the axial direction and which are arranged so as to be point symmetrical with respect to each other, a pair of upper and lower backup rolls which respectively support the work rolls, a work roll horizontal direction actuator which moves the work rolls in the horizontal direction, and a work roll axial direction actuator which moves the work rolls in the axial direction, a first angle control step of adjusting an angle between an upper pair of upper work rolls and upper backup rolls while keeping the upper pair of upper work rolls and upper backup rolls parallel and a lower pair of lower work rolls and lower backup rolls parallel; a second angle control step of tilting the work roll while maintaining the angle of the backup roll; an axial position control step of issuing a command to move the work roll in a direction in which a total thrust force that the work roll inclined by the second angle control step receives from the backup roll and the rolled material acts on the work roll; The rolling method according to claim 1,

9. The rolling method according to claim 8, The angle θwb between the work roll and the backup roll when the total thrust force becomes 0 ｂａｓｅ The method further includes an angle acquisition step of obtaining an angle In the second angle control step, when the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected to a concave shape direction, when the angle formed by the work roll inclined in the second angle control step and the backup roll is set to θwb, the angle θwb is equal to the angle obtained in the angle acquisition step. ｂａｓｅ Command it to get bigger, The axial position control step issues a command to bring the thickest diameter portions of the upper work roll and the lower work roll, which are in contact with the rolled material, closer to each other. The rolling method according to claim 1,

10. The rolling method according to claim 8, The angle θwb between the work roll and the backup roll when the total thrust force becomes 0 ｂａｓｅ The method further includes an angle acquisition step of obtaining an angle In the second angle control step, when the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected in a convex shape direction, when the angle formed by the work roll inclined in the second angle control step and the backup roll is set to θwb, the angle θwb is equal to the angle obtained in the angle acquisition step. ｂａｓｅ Give it a command to become smaller, The axial position control step issues a command to separate the thickest diameter portions of the upper work roll and the lower work roll that are in contact with the rolled material. The rolling method according to claim 1,

11. The rolling method according to claim 9, In the second angle control step, when the gap distribution between the upper work roll and the lower work roll in the axial direction is corrected in a convex shape direction, when the angle formed by the work roll inclined in the second angle control step and the backup roll is set to θwb, the angle θwb is equal to the angle obtained in the angle acquisition step. ｂａｓｅ Give it a command to become smaller, The axial position control step issues a command to separate the thickest diameter portions of the upper work roll and the lower work roll that are in contact with the rolled material. The rolling method according to claim 1,

12. The rolling method according to any one of claims 8 to 11, The rolling mill further includes a backup roll horizontal actuator that moves the backup roll in a horizontal direction, The first angle control step issues a command to tilt the upper pair of upper work rolls and upper backup rolls in directions opposite to each other in a horizontal plane while keeping the upper pair of upper work rolls and upper backup rolls parallel and keeping the lower pair of lower work rolls and lower backup rolls parallel. The rolling method according to claim 1,

13. The rolling method according to any one of claims 8 to 12, At least the second angle control step and the axial position control step are performed during rolling of the rolled material. The rolling method according to claim 1,

14. The rolling method according to any one of claims 8 to 13, The angle of the angle command value output in the second angle control step is smaller than the maximum angle of the angle command value output in the first angle control step. The rolling method according to claim 1,

Images