JPS6226843B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a roll bending method for a rolling mill having a work roll bending device for separating and approaching a pair of upper and lower work roll axes, and in particular, The present invention relates to a rolling mill roll bending control method suitable for a rolling mill work roll bending device arranged asymmetrically with respect to a line.

[Background of the invention]

A rolling mill based on a conventional rolling mill roll bending control method is configured as shown in FIG. That is, the upper and lower pair of upper work roll 1 and lower work roll 1' are the upper and lower pair of upper reinforcing rolls 2.
and a lower reinforcing roll 2', and at the shaft end of the upper work roll 1 there is an upper day crease bending device 3 that brings the distance between the work roll shafts closer together and an upper increase bending device 3 that increases the distance between the work roll shafts and increases the distance between the work roll shafts. A bending device 4 is provided at the shaft end of the lower work roll 1', and a lower increase bending device 3' for approaching the work roll shaft distance and a lower increase bending device 4 for increasing the work roll shaft distance apart. ' are provided in the upper work roll bearing box 5 and the lower work roll bearing box 5', respectively. Here, as shown in FIG. 2, the pair of upper and lower reinforcing rolls 2 and lower reinforcing rolls 2' are moved in the roll axis direction with respect to the upper work roll 1 and the lower work roll 1', and are moved along the rolling center line 1A. are arranged asymmetrically.

In a rolling mill in which the pair of upper and lower reinforcing rolls 2 and 2' are disposed asymmetrically with respect to the rolling center line 1A, one end of the upper work roll 1 and the lower work roll 1' is provided with upper reinforcement, respectively. Since it is not restrained by the roll 2 and the lower reinforcing roll 2', the bending force is significantly increased even with the same bending force. Especially as the sheet width becomes narrower, the roll bending effect becomes larger, and therefore the crown correction ability becomes larger. Therefore, the shape of the rolled material 6 can be controlled accurately.

However, in a rolling mill in which the upper reinforcing roll 2 and the lower reinforcing roll 2' are arranged asymmetrically with respect to the rolling center line, it is necessary to perform the upper work in order to perform uniform crown correction on the left and right sides of the rolled material 6. It is necessary to apply the roll bending force to the roll 1 and the lower work roll 1' to the rolled material 6 at least point-symmetrically.

That is, the conventional method of applying roll bending force to such a rolling mill is as follows: (1) Increase bending force F is applied to both shaft ends of the upper work roll 1 by the upper increase bending device 4, respectively.
_D and F _W are applied, and increase bending forces F _{D '} and F W ' are applied to both shaft ends _{of the lower work roll 1' by the lower increase bending device 4', and F D =} F _D ' When setting so that =F _W =F _W ′, increase bending forces F _D , F _W , F _D ′, F _W ′ are given as in (2) and (1), and F _D =F _W When setting so that 'F _D '=F _W , (3) Apply daily crease bending forces F _Dn and F _Wn to both shaft ends of the upper work roll 1 by the upper daily crease bending device 3. , the lower day crease bending device 3' applies day crease bending forces F _{Dn ′} and F Wn ′ to both shaft ends of the lower work roll 1 ′, and F _Dn =F _Wn ′F _Dn ′= _{F Wn} When setting it so that

These conventional roll bending control methods are
In either case, a bending force of equal magnitude is applied at least point-symmetrically to the center of the rolled material 6. Therefore, when adopting such a roll bending method, the work roll bending device at one end of either the upper work roll or the lower work roll is
The other end of the other work roll shall be equipped with work roll bending equipment of the same size.

In other words, in the conventional roll bending method, it is necessary to install a daily increase bending device and an increase bending device at both shaft ends of a pair of upper and lower work rolls, which complicates the structure and requires a large installation area. The disadvantage is that it must be secured.

[Purpose of the invention]

The purpose of the present invention is to focus on the difference in the bending effect between the ends of the upper and lower work rolls, and to mutually control the bending force applied to the shaft end of each work roll, thereby reducing the amount of crown change on the left and right sides of the rolled material. It is an object of the present invention to provide a roll bending control method for a rolling mill that can be adjusted to a desired value and that can perform efficient rolling work and effective shape control of rolled material using simple equipment.

[Summary of the invention]

The present invention provides a rolling mill in which a pair of upper and lower work rolls is supported by a pair of upper and lower support rolls, and the pair of upper and lower support rolls are arranged asymmetrically with respect to a rolling center line. An increase bending device for separating the distance between the work roll shafts and a day increase bending device for reducing the distance between the work roll shafts are provided at both shaft ends of one of the work rolls, and one of the upper work rolls and the lower work roll is , an increase bending device is provided at both shaft ends of the other work roll to increase the distance between the work roll shafts, and the amount of change in plate crown for a unit roll bending force applied to the side of the work roll that is less constrained by the support roll is calculated. α is the amount of plate crown change with respect to the unit roll bending force applied to the side of the work roll that is more constrained by the support roll; β is the work roll of the work roll on the side that is less constrained by the support roll of one of the upper and lower work rolls. The daily crease bending force acting on the work roll is F _Wn , the increase bending force is F _W , and the day crease bending force acting on the work roll that is more constrained by the support roll in one of the work rolls is F _Dn , The increase bending force is F _D , and the increase bending force acting on the work roll on the side of the upper and lower work rolls that is less constrained by the support roll on the other work roll is F _D ′, the other work roll Let F _W ' be the increase bending force acting on the work roll that is more constrained by the support roll, and the amount of plate crown change due to the roll bending forces F _W , F _W ', and F _Wn ΔC _W ΔC _W = αF _W +βF _W ′−αF _Wn and the roll bending force as F _D , F _D ′, F _D
The shape of the rolled material is controlled by controlling each roll bending force so that the plate crown change amount ΔC _D ΔC _D = αF _D +βF _D '−αF _Dn due to _n is approximately equal. This is a characteristic feature.

[Embodiments of the invention]

Examples of the present invention will be described below.

FIG. 3 is an explanatory diagram showing a rolling mill equipped to carry out the roll bending method for a rolling mill according to the present invention. That is, in this rolling mill, the upper increase bending device 4 and the lower increase bending device 4' are provided at the shaft ends of the upper work roll 1 and the lower work roll 1', respectively, as in the conventional case. , the day crease bending device is equipped with only the upper day crease bending device 3 for the upper work roll 1,
The lower work roll 1' is not equipped with a conventional lower day clean bending device, and the structure is simplified.

FIG. 4 is an explanatory diagram showing a state in which roll bending force is acting on each work roll in a rolling mill equipped as shown in FIG. 3, with the bending of the work rolls exaggerated. In FIG. 4, let us assume that the left side is the operation side and the right side is the drive side, and the side where the work rolls 1, 1' are less constrained by the reinforcing rolls 2, 2' (the upper work roll 1 is on the operation side, the lower work roll 1 is on the operation side, ′, the plate crown change amount with respect to the unit roll bending force applied to the drive side) is α, and the reinforcing roll 2 of work roll 1, 1′,
Let β be the amount of plate crown change with respect to a unit roll bending force applied to the side where the restriction by 2' is greater (the drive side for the upper work roll 1 and the operation side for the lower work roll 1'). In addition, the contact surface length between the upper work roll 1 and the upper reinforcing roll 2 on the operating side with respect to the rolling center line 1A is l _W (1/2 of the sheet width),
The length of the contact surface between the upper work roll 1 and the upper reinforcing roll 2 on the drive side with respect to the rolling center line 1A is l _D (1/2 or more of the sheet width).

In FIG. 4, an increase bending force F Wn and an increase bending force F W act on the operation side of the upper work roll 1, and an increase bending force F _{Dn and an increase bending force F D act} on the drive side. An increase bending force F _D is being applied.
Further, an increase bending force F _W ' is applied to the operation side of the lower work roll 1', and an increase bending force F _D ' is applied to the drive side.

Therefore, the roll bending force F _W on the operating side,
Plate crown change amount ΔC _W due to F _W ' and F _Wn
is expressed as ΔC _W =αF _W +βF _W ′−αF _Wn (1). Further, the amount of plate crown change ΔC _D due to the roll bending forces F _D , F _D ', and F _Dn on the drive side is expressed as ΔC _D =βF _D +αF _D '−βF _Dn (2). Except for special cases, it is preferable that the amount of change in plate crown on the operating side ΔC _W and the amount of change in plate crown on the drive side ΔC _D be changed equally. In other words, it is desirable to control each roll bending force so that ΔC _W =ΔC _D (3), and by substituting equations (1) and (2) into equation (3), α(F _W −F _D ′−F _Wn )=β(F _D −F _W ′−F _Dn )
…(4) The following relational expression is obtained. In other words, in order to control the amount of plate crown change equally on the operating side and the driving side,
The magnitudes of the roll bending forces F _D , F _W , F _D ', F _W ', F Dn _{and F Wn may} be mutually controlled so as to satisfy the relationship in equation (4).

Furthermore, in FIG. 4, if the increase bending forces F _D , F _W , F _D ′ and F _W ′ are not applied, the increase bending forces F _Wn and F _{Dn
In order} to equalize the amount of plate crown change _on the operation _side and drive _side by applying only =βF _Dn ……………(6) Let the daily bending force F Wn applied to the operation side of the upper work roll 1 and the daily crease bending force F _Dn applied to the drive side be expressed _as follows. It would be better if they could control each other.

Note that the values of α and β are generally not equal;
It is a function of the contact surface length l _o between the work roll and the reinforcing roll, and can be known in advance by experiment or calculation.

For example, the ratio between α and β increases as l _W becomes smaller, as shown in FIG. Therefore, if the relationship shown in Fig. 5 is determined in advance and stored in the pressure control device, the daily increasing bending force and the increasing bending force can be automatically set by the l _W signal. can. Furthermore, by knowing the above relationship in advance, it is also possible to manually set the magnitudes of the daily increasing bending force and the increasing bending force.

Generally speaking, the plate crowns on the entry side of rolled material are not only equal on the left and right sides, but also the amount of plate crown change on the operating side and the plate crown on the driving side are set to different values in order to obtain the desired plate crown, as in the case of wedged materials. It may be necessary to configure. In this case, the plate crown change amount ΔC _W on the operating side and the plate crown change amount ΔC _D on the driving side are ΔC _W =nΔC _D (n≠1) (7). Therefore, in this case (1), (2) and (7)
From the formula, α(F _W −nF _D ′−F _Wn )=β(nF _D −F _W ′−
nF _Dn ) ……………(8) If the values of each roll bending force F _W , F _D ′, F _Wn , F _D , F _W ′, and F _Dn are mutually controlled so that the following relationship is established, good. Therefore, for example, if the increase bending force is set to satisfy F _W = nF _D ′, nF _D = F _W ′ (9), the increase bending force on the operating side F _Wn By controlling each other so that the daily crease bending force F Dn and the daily bending force F _Dn on the driving side satisfy the relationship αF _Wn = nβF _Dn (10), the desired sheet crown change can be obtained. become.

FIG. 6 is an explanatory diagram showing a control system employed when carrying out the roll bending method for a rolling mill according to the present invention. In FIG. 6, a daily bending cylinder 7 is provided on the operation side of the upper work roll 1, and a daily crease bending cylinder 8 is provided on the drive side.
Further, a single increase bending cylinder 10 is provided on the operating side of the upper work roll 1 and the lower work roll 1', and this increase bending cylinder 10 is used for the operation side of the upper work roll 1 and the lower work roll 1'. An increase bending force of the same magnitude is applied to the operating side.
Further, a single increase bending cylinder 9 is provided on the driving side of the upper work roll 1 and the lower work roll 1'.
The same amount of increase bending force is applied to the drive side of the motor. The day crease bending cylinder 8 is connected to a proportional pressure reducing valve 1 by a pipe line 8A having a stopper valve 11, and the day crease bending cylinder 7 is connected to a proportional pressure reducing valve 1 by a pipe line 7A having a stopper valve 12.
Connected to 3. This proportional pressure reducing valve 13 is connected to a pressure control device 14 via a pipe 13A. Moreover, this pressure control device 14 is connected to a pressure generator 15 via a pipe line 14A, and this pressure generator 15 is connected to a tank 15B via a pipe line 15A. Note that the pressure control device 14 determines α/β using the plate width signal 14B, that is, l _W ,
It is designed to be controlled by the value of α/β. The pressure generator 15 also includes a stop valve 1.
6 is connected to the pressure reducing valve 19 by a conduit 16A. This pressure reducing valve 19 is connected to the pipe lines 19A, 1
It is connected to the increase bending cylinder 9 via 9B, and to the increase bending cylinder 10 via conduits 19A and 19C. Note that a pipe line 17A including a manual pressure reducing valve 17 connects the pipe line 14A and the pipe line 8A,
Further, a conduit 18A including a manual pressure reducing valve 18 connects the conduit 14A and the conduit 7A. Further, a pipe 7B is connected to the pipe 7A, a pipe 8B is connected to the pipe 8A, and a pipe 1 is connected to the pipes 19B and 19C.
9D is connected, and these pipes 7B, 8B, 19
D are each communicated with the tank 15B.

In the control system shown in FIG. 6, an increase bending force is applied to the upper work roll 1 and the lower work roll 1' on the operation side and the drive side,
The magnitude of these increase bending forces is the same on the operation side and the drive side of the upper work roll 1 and the lower work roll 1', and the increase bending force is the same on the operation side and the drive side of the upper work roll 1. This makes it possible to mutually control these daily bending forces.

That is, the fluid made high pressure by the pressure generator 15 is controlled by the pressure controller 14 to control the pressure applied to the operation side and the pressure to be applied to the drive side of the upper work roll 1, and is controlled by the proportional pressure reducing valve 13. The pressure is reduced to a pressure controlled by the pressure control device 14, and the cylinder 7 for day crease bending is provided on the operation side of the upper work roll 1, and the cylinder 7 for day crease bending is provided on the drive side of the upper work roll 1. The cylinder 8 is pressurized to apply daily bending force in a direction that causes the upper work roll 1 to approach the lower work roll 1'.

On the other hand, the pressure generated by the pressure generating device 15 is reduced to a preset pressure by a pressure reducing valve 19, and the pressure generated by the pressure generating device 15 is reduced to a preset pressure by a pressure reducing valve 19. The increase bending cylinder 10 and the increase bending cylinder 9 provided on the driving side are actuated to increase bending in the direction of increasing the distance between the upper work roll 1 and the lower work roll 1'. force is applied.

The relationship between the daily increase bending force applied by the daily increase bending cylinders 7 and 8 and the increase bending force applied by the increase bending cylinders 9 and 10 is When the amount of change in plate crown on the drive side is made equal, the setting is made to satisfy the above equation (4), and when the amount of change in the plate crown on the operating side and the drive side is set to satisfy the above equation (7). The pressure control device 14 may be used to control the pressure so as to satisfy the equation (8).

In addition, the amount of change in the plate crown is determined by the manual pressure reducing valve 17,
18 can also be arbitrarily changed. Note that in implementing the roll bending method for a rolling mill according to the present invention, manual pressure reducing valves 17, 1
It may be carried out only by 8,
Alternatively, the desired plate crown variation may be obtained only by the pressure control device 14.

Next, FIG. 7 is an explanatory diagram showing another control system applied to the implementation of the roll bending method for a rolling mill according to the present invention. In FIG. 7, a daily increasing bending cylinder 7 and an increasing bending cylinder 22 are provided on the operating side of the upper work roll 1, and a daily increasing bending cylinder 8 and an increasing bending cylinder 22 are provided on the driving side. A deing cylinder 25 is provided. Further, an increase bending cylinder 23 is provided on the operation side of the lower work roll 1', and an increase bending cylinder 24 is provided on the drive side. The increase bending cylinders 23 and 24 are connected to a proportional pressure reducing valve 13 via pipes 23A and 24A, respectively, and this proportional pressure reducing valve 13 is connected to a pressure control device 14 via a pipe 13A.
It is connected to the. Further, the increase bending cylinders 22 and 25 are connected to the pipe lines 22A and 25, respectively.
25A to a proportional pressure reducing valve 20, and this proportional pressure reducing valve 20 is connected to the pressure control device 14 via a conduit 20A. Also, the daily bending cylinders 7 and 8 are connected to the pipe line 7, respectively.
A, connected to the proportional pressure reducing valve 21 via 8A,
This proportional pressure reducing valve 21 is connected to the pressure control device 14 via a pipe line 21A. This pressure control device 14 is connected to a pressure generator 15 via a pipe line 14A, and this pressure generator 15 is connected to a tank 15B via a pipe line 15A. Note that the pressure control device 14 is controlled by a plate width signal 14B.

In the control system shown in FIG. 6, the pressure generated by the pressure generator 15 is applied to the operation side and drive side of the upper work roll 1 by the pressure control device 14, and the pressure generated by the pressure generator 15 is applied to the operation side and the drive side of the upper work roll 1. A bending force is applied, and an increase bending force is applied to the operating side and the driving side of the lower work roll 1'. These increase bending force and day increase bending force are mutually controlled so as to satisfy the above equation (4) when the plate crown change amount on the operation side and the drive side are made equal, and In order to make the amount of plate crown change on the side and drive side satisfy the above equation (7), it is sufficient to mutually control them so as to satisfy the above equation (8). In addition, in this FIG. 7, the manual pressure reducing valve may be manually controlled as in FIG. 6, and both the manual pressure reducing valve, the pressure control device, and the proportional pressure reducing valve may be used. It may be controlled using.

Further, FIG. 8 is an explanatory diagram showing another control system applicable in implementing the roll bending method for a rolling mill according to the present invention. In FIG. 8, a daily bending cylinder 27 is provided on the operation side of the upper work roll 1, and daily crease bending cylinders 28, 2 are provided on the drive side.
9 is provided. Further, a single increase bending cylinder 10 is provided on the operation side of the upper work roll 1 and the lower work roll 1', and a single increase bending cylinder 9 is also provided on the drive side. . The increase bending cylinders 9 and 10 are connected to pipe lines 9A and 10, respectively.
It is connected to the pressure reducing valve 19 via 9B and 10A, 9B. This pressure reducing valve 19 is connected to the pressure generator 15 via lines 19A and 19B which are provided with stop valves. Further, the daily bending cylinders 27 and 28 are connected to pipes 27A and 27B and pipes 28A and 27, respectively.
It is connected to the pressure reducing valve 30 via B, and this pressure reducing valve 3
0 is connected to the pressure generator 15 via a line 30A with a stop valve and a line 19B. This pressure generator 15 is communicated with a tank 32 via a pipe line 15A.

The daily bending cylinder 29 is connected to a pressure reducing valve 31 via a pipe 29A, and the pressure reducing valve 31 is connected to the pressure control device 14 via a pipe 31A. This pressure control device 14 is connected to the pressure generating device 15 via a pipe line 14A.
It is connected to the. Further, the pressure control device 14 can determine α/β in FIG. 5 from the plate width signal 14B, that is, l _W that determines the daily increase bending force and the increase bending force, and the pressure control device 14 can control the pressure by using this α/β. It is becoming more and more common.

In the control system shown in FIG. 8, the pressure generated by the pressure generator 15 is applied to the increase bending cylinders 9 and 10 and the day increase bending cylinders 9 and 10, respectively, through the pressure reducing valve 19 and the pressure reducing valve 30. cylinder 27,2
8 to apply an increase bending force to the operation side and drive side of the upper work roll 1 and lower work roll 1', and to apply a decrease bending force to the operation side and drive side of the upper work roll 1. It is beginning to give. Furthermore, if it is necessary to change the roll bending force applied to the upper work roll 1 and the lower work roll 1' based on these pressure reducing valves 19 and 30,
The pressure applied to the daily bending cylinder 29 may be adjusted by controlling the pressure control device 14 and the pressure reducing valve 31.

That is, in the control system shown in FIG. 8, in addition to the increase bending cylinders 9 and 10 for fixed use and the daily increase bending cylinders 27 and 28, a daily increase bending cylinder 29 is used for adjustment. By adding it, it becomes possible to control the shape of the rolled material 6 more accurately.

In each of the above embodiments, the roll bending method of a rolling mill according to the present invention has been explained in the case where the rolling mill has a pair of upper and lower work rolls and a reinforcing roll. A second upper reinforcing roll 26 and a second reinforcing roll 2 are installed above and below the reinforcing rolls 2 and 2', respectively.
Of course, the present invention can also be applied to a rolling mill equipped with 6'.

Further, in each of the above embodiments, the case where the daily crease bending device is provided on the upper work roll has been described, but the present invention may be such that the daily crease bending device is provided only on the lower work roll.

Furthermore, in each of the above embodiments, the case where the increase bending device is provided on both the upper work roll and the lower work roll has been described.
The present invention is also applicable to a rolling mill in which an increase bending device is provided only on either the upper work roll or the lower work roll.

Furthermore, in each of the above embodiments, a method of roll bending by applying pressure to both axial ends of the work roll was explained, but the present invention describes a method in which a rotational moment is applied to both axial ends of the work roll. Of course, it is also applicable to.

〔Effect of the invention〕

As explained above, according to the present invention, efficient rolling work and effective shape control of the rolled material can be performed with simple equipment.

Further, according to the present invention, accurate rolling control can be performed by equally controlling the amount of change in the two plate crowns due to the roll bending force.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a rolling mill according to a conventional roll bending method, FIG. 2 is a front view showing the operating state of the same roll bending force, and FIG. 3 is a roll bending of a rolling mill according to the present invention. A cross-sectional view showing a rolling mill according to an embodiment of the method, FIG. 4 is a front view showing the operating state of the roll bending force, and FIG. 5 shows the relationship between the ratio of left and right bending effects and the contact surface length. Fig. 6 is a control system diagram suitable for the roll bending method of a rolling mill according to the present invention, Fig. 7
8 is another control system diagram, FIG. 9 is a sectional view showing a rolling mill according to another embodiment of the roll bending method for a rolling mill according to the present invention, and FIG. FIG. 10 is a front view showing the operating state of the roll bending force. 1...Upper work roll, 1'...Lower work roll,
2... Upper reinforcing roll, 2'... Lower reinforcing roll,
7, 8, 27, 28, 29...Cylinder for daily bending, 9, 10, 22, 23, 2
4, 25... Cylinder for increase bending.

Claims (1)

[Claims] 1. In a rolling mill in which a pair of upper and lower work rolls are supported by a pair of upper and lower support rolls, and the pair of upper and lower support rolls are arranged asymmetrically with respect to the rolling center line, the upper work roll and the lower work roll are supported by a pair of upper and lower work rolls. An increase bending device for increasing the distance between the work roll axes and a daily increase bending device for reducing the distance between the work roll axes are provided at both ends of one of the work rolls, and the upper work roll and the lower work roll Among the rolls, an increase bending device is provided at both shaft ends of the other work roll to increase the distance between the work roll shafts, and a plate crown is applied to the unit roll bending force applied to the side of the work roll that is less constrained by the support roll. The amount of change is α, the amount of plate crown change with respect to the unit roll bending force applied to the side of the work roll that is more constrained by the support roll is β, and the side that is less constrained by the support roll of one of the upper and lower work rolls. The daily crease bending force acting on the work roll is F _Wn , the increase bending force is F _W , and the day crease bending force acting on the work roll on the side that is more constrained by the support roll in the one work roll is F
_Dn , the increase bending force is F _D , and the increase bending force acting on the work roll of the upper and lower work rolls that is less constrained by the support roll of the other work roll is F.
_D ′, the increase bending force acting on the work roll on the side that is more constrained by the support roll in the other work roll is F _W ′, and the plate crown due to the roll bending forces F _W , F _W ′, and F _Wn is The amount of change ΔC _W ΔC _W = αF _W +βF _W ′−αF _Wn and the roll bending force are expressed as F _D , F _D ′, F _D
The shape of the rolled material is controlled by controlling each roll bending force so that the plate crown change amount ΔC _D ΔC _D = αF _D +βF _D '−αF _Dn due to _n is approximately equal. Features: Roll bending control method for rolling mills.