JP2007253171A - Method for manufacturing rolled stock and device for clamping roll chock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a rolled stock and a device for clamping a roll chock for obtaining the rolled stock excellent in dimensions and a shape by reversing rolling. <P>SOLUTION: The operation of the device for clamping the roll chock is started linking with the operation starting signal of a bender of a reversing rolling mill 1, and the chock is clamped by a large force of constraint until a preset time lapses. Next, the chock is clamped by a small force of constraint until a preset time 2 lapses after a sheet is bitten and the large force of constraint is set in steady rolling. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a rolled material such as a rough bar or a thick steel plate by a reversible rolling mill such as a rough rolling mill or a thick plate rolling mill, and a roll chock clamp device used for the method, and in particular, rolling excellent in size and shape. It relates to the technology from which materials are obtained.

  In a rolling mill that rolls a steel sheet hot or cold, a slight gap is provided between a roll chock (bearing box) of a work roll and a housing of the rolling mill. This gap facilitates the roll exchanging work, but causes the relative positional relationship between the work roll and the backup roll to fluctuate during the rolling work. If both ends of the roll chock (bearing box) of the work roll move back and forth in the horizontal direction and the relative positional relationship between the work roll and the backup roll fluctuates, the rolled material will bend (camber) and geometrically Various measures have been proposed because the roll gap varies and the plate thickness accuracy decreases.

  For example, Patent Document 1 relates to a rolling mill and a rolling method, in a rolling mill provided with a movable frame between a roll chock and a rolling mill housing, and provided with a first hydraulic device for performing roll balance and the like on the movable frame. A second hydraulic unit that presses and restrains the roll chock and the movable frame in the flow direction of the rolling material and a third hydraulic unit that presses and restrains the movable frame in the vertical direction are further provided, whereby the second hydraulic unit performs rolling. Rolling with less indentation and stable rolling with less meandering of the rolled material is possible, and the third hydraulic device prevents the rolling mill from resonating due to the cylindrical roller of the roll shaft rolling bearing, and rolling without indentation It has been proposed to be able to obtain a material.

  Moreover, in patent document 2, regarding the rolling mill and the rolling method which suppress the shakiness of the axial direction of a work roll and the sheet passing direction, the power clamp apparatus which restrains the roll chock which supports a work roll is provided in a housing, The said power clamp The apparatus uses a rolling mill that engages the housing and roll chock to suppress the shakiness of the work roll in the axial direction and the sheet passing direction, and uses the rolling mill to drive the power clamp device at a low pressure during the steady operation of the rolling mill. In addition, a rolling method has been proposed that is driven at a high pressure when biting and falling off.

  Moreover, in patent document 3, regarding the roll chock clamp device, a plurality of hydraulic cylinders are arranged on the housing side corresponding to the end portions of the roll chock, and each cylinder stops pressing so that its piston abuts on the roll chock. When all the cylinders are in an unbalanced state by maintaining the state and minimizing the influence on the plate thickness control device (AGC device), and by sharing the flow path of each cylinder, It has been proposed to be able to touch a roll chock.

  Here, in the rolling of a hot-rolled steel sheet, when focusing on one rolling mill, the rolling biting is performed once per sheet, and the time interval from the end of rolling to the start of the next rolling is around 1 minute. Therefore, there is sufficient time for switching the roll chock clamp device to ON / OFF or pressure change. Therefore, when rolling hot-rolled steel sheets, for example, when finishing with a multi-stage continuous rolling mill, the operation start of the roll chock clamping device may be interlocked with a signal indicating that the leading end of the sheet has passed through the preceding rolling mill.

Furthermore, in rolling hot-rolled steel sheets, meandering of the plate during unsteady conditions such as when the tip is bitten or when the tail end is pulled out often becomes a problem, and after the tip of the plate reaches the hot-rolling coil take-up device No operation switching of the roll chock clamp device during steady rolling has been performed in the conventional steady state.
JP 2002-143912 A JP 2001-198609 A JP 2001-340906 A

  On the other hand, in rolling rough bars and thick steel plates, the steel material is rolled by a reversible rolling machine that rotates the work roll forward and backward, and the rolling horizontal position of the roll chock varies due to the rolling horizontal shake of the roll chock. An error in the thickness of the rolled material due to the occurrence of the camber due to the left-right asymmetry of the horizontal position of the roll chock in the rolling direction may occur. In particular, when a reversible rolling mill having a roll shift function for shifting in the axial direction of the roll shaft is used, the roll wear is not uniform, so that a plate thickness error and camber are likely to occur.

In addition, the roughing and thick plate mills, which are representative of reversible rolling mills, have a higher rolling load than the thin plate rolling mills that roll hot-rolled and cold-rolled steel plates. On the other hand, it is necessary to adjust the operation time and timing for rolling such as sheet thickness control, and an accurate clamping means that balances both of them is required.
Furthermore, in the case of a reversible rolling mill, the time until the next rolling, such as the time from forward rolling to reverse rolling, is very short, during which the side guide adjustment, work roll opening tightening, In order to perform various operations such as roll movement in the roll direction (roll shift), rotation in the rolling direction (roll cross), and roll deflection correction (roll bender), the roll chock clamping device is also performed from the end of rolling to the start of rolling. Clamping needs to be started without interference with the above-described devices other than the roll chock clamp device, and the operation start timing is limited. Conventionally, a good means for determining the timing of starting the chock clamping operation in forward / reverse rolling of a reversible rolling mill has not been clarified.

  In addition, as described above, the rolling load is larger than that of the sheet rolling mill, and interference with the sheet thickness control device becomes a problem. Therefore, the means for appropriately changing the restraining force is not a constant restraining force even after the chock clamping is started. However, the magnitude and method of changing the restraint force that restrains the fluctuation of the roll chock of the reversible rolling mill appropriately and avoids the interference with the sheet thickness control device are unknown. In particular, during rolling, a method of changing the restraining force for choke clamping depending on the rotation direction and rotational acceleration of the work roll has not been clarified in the prior art.

Furthermore, in order to alleviate the impact and wear received by the roll chock clamp device, it is better to set the minimum restraining force to keep the chock variation within a predetermined range.
Here, Patent Documents 1 to 3 do not particularly target reversible rolling, and do not show a rolling method using a reversible rolling mill equipped with a roll chock clamp device in rough rolling of slabs or thick plate rolling.

  Further, Patent Document 2 is a method in which the clamping device is driven at a low pressure during the steady operation of the rolling mill and is driven at a high pressure at the time of biting and slipping, but the driving timing of the clamping device has been clarified. Absent. When a reversible rolling mill is clamped at a high pressure using the clamping method of Patent Document 2, in some cases, a chock is caught in the housing of the rolling mill and does not move up and down, and the thickness control at the tip of the thick plate May not be possible.

  At the time of steady rolling of a hot-rolled steel plate, the tip of the plate is taken up by a coil winding device, so that the chock is relatively stabilized by the tension of the plate. When clamping at the time of steady rolling at a low pressure, there is a problem that the chock is unstable due to the absence of plate tension even at the time of steady rolling, or the chock moves because the rotation speed of the work roll is changed. However, it was not clarified under what conditions the chock moved.

For the above reasons, the problem is how to switch the restraint force of the chock clamp device to what size and at what timing in a short reversible rolling operation.
Then, an object of this invention is to provide the manufacturing method of the rolling material by the reversible rolling mill provided with the roll chock clamp apparatus which can be clamped by appropriate restraint force, and such a roll chock clamp apparatus.

In the case of rolling a thick steel plate by attaching a roll chock clamp device to a reversible rolling mill, the present inventors sufficiently restrain the roll chock with the roll chock clamp device before the thick steel plate bites between the upper and lower rolling rolls. It has been found that there are rolling conditions in which the rolling horizontal direction is less likely to occur even if the restraining force is lowered after biting.
Moreover, the restraint force when the roll chock was always clamped during rolling was considered, and it was found that there was a restraint force with little influence on the plate thickness control device. Moreover, since the impact load in the horizontal direction increases before and after the thick steel plate is bitten, it has been found that the influence on the plate thickness control device can be prevented by reducing the restraining force. This is a concept opposite to the conventional one in which high pressure is applied at the time of biting as disclosed in Patent Document 2.

  Moreover, the operation start of the roll chock clamp device is linked to the operation signal of a pressing device such as a bender device that operates before the start of rolling, and the switching of the restraining force is performed by setting time 1 from the operation start signal of the bender device and starting the rolling. It has been found that setting time 2 from the operation signal is effective. Depending on the setting of the setting time 1 and the setting time 2, the restraining force during rolling can be arbitrarily switched between large and small, and only one control program is required, and system maintenance is easy.

  Further, in the reversible rolling mill in which the axis of the work roll is offset in the rolling forward direction from the axis of the backup roll, the restraint force required by the roll chock clamp device for restraining the work roll in the rolling forward direction is: It was found that it was small during forward rolling and large during reverse rolling. In addition, during positive acceleration rotation from the rolling reverse rotation maximum speed to the forward rotation maximum speed, the work roll moves in the rolling forward direction, so the restraining force required is small, and conversely the negative rotation from the normal rotation maximum speed to the reverse rotation maximum speed. During acceleration rotation, it became clear that the restraining force required for the work roll to move in the reverse direction of rolling increased.

In the present invention, the thick steel plate refers to a steel plate having a thickness of 4 mm or more, which is usually produced as a thick steel plate.
Based on such knowledge, the invention described in claim 1 of the present invention is a reversible rolling mill provided with a roll chock clamp device that restrains a roll chock of a work roll in a direction along the rolling direction.
When the rolled material is restrained by applying a first restraining force to the roll chock before the rolled material bites into the work roll, and the impact load when the rolled material bites into the work roll is estimated to be greater than a predetermined value, rolling The present invention provides a method for producing a rolled material, characterized in that the setting is changed to a second restraining force smaller than the first restraining force before the material bites into the work roll.

Next, the invention described in claim 2 is provided in a reversible rolling mill, and a clamp device main body for restraining the roll chock by applying a restraining force in the direction along the rolling direction to the roll chock of the work roll, and a clamp A roll chock clamp device comprising a restraining force controller for controlling the restraining force by the device body,
The restraint force controller includes, as the restraint force, a first restraint force for restraining the roll chock by moving in a direction in which the backlash is eliminated, a second restraint force smaller than the first restraint force, and a roll choc during rolling. The first restraining force before the rolling material bites into the work roll, and after the setting of the first restraining force, the rolled material Is set to the second restraining force before biting, and is set to the third restraining force when the biting of the rolled material is completed.

Next, the invention described in claim 3 is the configuration described in claim 2, wherein the second restraining force is based on an estimated collision load that is expected to occur when the rolled material bites into the work roll. When it is determined that it is less than the predetermined collision load, the second restraining force is set to the same value as the first restraining force, and when it is determined to be equal to or greater than the predetermined collision load, the second restraining force is set to the first restraining force. It is characterized in that it is set to a value smaller than the force.
Next, in the invention described in claim 4, the work roll is less likely to be displaced in the direction opposite to the direction in which the restraining force is applied by the clamping device main body during rolling with respect to the configuration described in claim 2 or claim 3. When the determination is made, the magnitude of the third restraining force is set equal to the second restraining force.

Next, the invention described in claim 5 is directed to the configuration described in any one of claims 2 to 4, wherein the reversible rolling mill has a work roll whose axis is more than the axis of the backup roll. Is also offset in the rolling positive direction, and the clamp device body presses and restrains the roll chock in the rolling positive direction,
The restraint force controller sets the third restraint force smaller than the first restraint force when rolling in the forward rolling direction, and the third restraint force when rolling in the direction opposite to the forward roll direction. The force is set equal to the first restraining force.

Next, the invention described in claim 6 is directed to the configuration described in any one of claims 2 to 4, wherein the reversible rolling mill has a work roll whose axis is more than the axis of the backup roll. Is also offset in the rolling forward direction, and the clamp device body restrains the roll chock in the rolling forward direction,
A work roll rotation speed detection means and acceleration detection means,
When the restraint force controller determines that the work roll is rotating in the forward direction of rolling and decelerating or rotating in the reverse direction of rotation and accelerating, the third restraining force is set equal to the first restraining force 1 and the work roll is in the forward direction of rolling. In rotation and acceleration rotation or rolling reverse rotation and deceleration rotation, the third restraining force is equal to or smaller than the second restraining force.

Next, the invention described in claim 7 is directed to the configuration described in any one of claims 2 to 6, wherein the reversible rolling mill presses the rolling roll in a direction along the reduction direction. A pressing device,
The start of the operation of the load of the first restraining force is before or at the same time as the operation of the pressing device.

  According to the present invention, at least the restraining force at the time of biting of the rolled material into the rolling mill is adjusted to an appropriate value, thereby suppressing the adverse effect on the life of the rolling mill and obtaining a rolled material excellent in plate shape. Is possible.

Next, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a reversible rolling mill (hereinafter simply referred to as a rolling mill) provided with a roll chock clamp device according to the present embodiment.
(Constitution)
First, the configuration will be described. The work rolls 3 that are paired up and down across the pass line are arranged. Reference numeral 2 denotes a backup roll 2, and the work roll 3 is arranged offset from the backup roll 2 by an offset amount d on the downstream side. Reference numeral 4 denotes a roll chock of the work roll 3. Reference numeral 5 denotes a shift block that takes a reaction force on the housing, and is arranged with a gap a between the roll chock 4 on the downstream side.
Reference numeral 6 denotes a clamp device body. The clamp device body 6 is constituted by, for example, a hydraulic cylinder device, and applies a reaction force to the housing against the roll chock 4 from the upstream side toward the downstream side. The clamp device body 6 generates a restraining force according to a command from the restraining force controller 20.

Here, in the rolling mill 1, the work roll 3 is attached to the backup roll 2 while being offset by a distance d on the downstream side (forward direction of rolling), so that the work roll is being rolled from the upstream side to the downstream side. 3, a force pressing the roll chock 4 against the shift block 5 on the downstream side acts. However, the horizontal force applied to the work roll 3 is complicatedly balanced not only by the offset component force from the backup roll 2, but also by the friction force with the plate of the rolled material, the friction force with the backup roll 2, etc. Thus, the work roll 3 fluctuates in the horizontal direction.
When the work roll 3 moves in the horizontal direction, the roll gap fluctuates, the reduction amount fluctuates, and the plate thickness accuracy decreases, so that the roll chock clamp device prevents the gap a between the roll chock 4 and the shift block 5 from fluctuating. 6, it is necessary to press the roll chock 4 against the shift block 5 on the downstream side with an appropriate restraining force.

  The rolling mill 1 is provided with a bender device 11 that constitutes a pressing device. The bender device 11 is a device that applies a load to the left and right roll chock 4 in a direction along the rolling-down direction. The bender device 11 loads the load before the rolled material bites into the work roll 3, and reverses the work roll 3. For example, the work roll 3 being rolled after the rolled material is caught is rolled in a flat state. The bender device 11 may be an example of a device that applies a load to the roll chock 4 in a direction along the reduction direction, and may use an operation start signal of another pressing device.

Next, the restraining force controller 20 will be described.
The restraint force controller 20 includes a first restraint force F1 which is set based on the rolling load and other information and is necessary for restraining the roll chock 4 against the shift block 5, and the first restraint force F1. A smaller second restraining force F2 and a third restraining force F3 for restraining the roll chock 4 during rolling are set. In the present embodiment, the first restraining force F1 and the third restraining force F3 are described as the same value. Of course, since the purposes are different, the first restraining force F1 and the third restraining force F3 do not have to be the same value.

  And the binding force controller 20 inputs the operation start signal, the rolling start signal, and the rolling end signal of the bender device 11, supplies the operation command to the clamp device body 6 in synchronization with the operation start signal, and outputs the rolling end signal. When input, an operation end signal is output to the clamp device body 6. Further, a command value corresponding to the first restraining force F1 is output to the clamping device body 6 as a restraining force at the start of operation, and a command value corresponding to the second restraining force F2 after a set time 1 has elapsed from the start of the operation. When a set time 2 has elapsed from the rolling start signal, a command value corresponding to the third restraining force F3 is output. Further, when a rolling end signal is input, an operation end signal is supplied to the clamping device main body 6 to stand by.

In addition, the said command value is implement | achieved by changing the discharge pressure of a pump by supplying to hydraulic control parts 21, such as a pump which pumps hydraulic fluid to the cylinder chamber of the clamp apparatus main body 6, for example.
Here, when the start of the bender device 11 is set to 3 seconds before the start of rolling, the set times 1 and 2 are set to be a response delay, for example, the set time 1 is 2 seconds and the set time 2 is 1 second. This should be set in consideration.

(Action, effect, etc.)
In the present embodiment, the thick steel plate is rolled by the rolling mill 1, the roll chock 4 is restrained by the roll chock clamp device 6 before the thick steel plate is bitten, and the restraining force is switched depending on the rolling load or the like.
Here, since the roll chock 4 is clamped in the horizontal direction, there is a concern about the influence on the plate thickness control device acting in the vertical direction, but the plate thickness control device is clamped with an appropriate restraint force according to the rolling conditions. It was found that there was little influence on In particular, when the thick steel plate is bitten, the load in the horizontal direction becomes large, so it is necessary to reduce the restraining force.

Next, control of the roll chock clamp device will be described. FIG. 2 shows the time chart.
The operation is started and restrained in conjunction with the operation start signal of the bender device 11 that operates before the start of rolling. Since the bender device 11 is weighted in the vertical direction of the roll chock 4 of the work roll 3, it interferes with the horizontal direction of the roll chock clamp device. In this embodiment, the operation of the bender device 11 is used to delay the clamping device. Can be made to function first. In some cases, the signal may be linked with the signal preceding the bender device 11 so as not to interfere with the clamp device. As long as it is a signal of a device that weights the work roll 3 like the bender device 11, it may be linked with other operations. Since this is a stage in which the work roll 3 is weighted, an operation start signal as an interlock that the roll chock clamp device can also be operated is taken into consideration.

  That is, the first restraining force F1 is set to a required large restraining force in order to move the roll chock 4 until it abuts against the shift block 5 by operating the roll chock clamping device in a state where a load is applied by the bender device 11. Although it is necessary to apply the restraining force before the loading by the bender device 11 is completed, the first restraining force F1 can be set to be small accordingly.

In general, since the normal bender operation is started under the condition that the work roll shift operation for moving the roll chock 4 in the plate width direction has been completed, the work roll can be operated in conjunction with the operation of the roll chock clamp device. Interference with the shift device can be avoided.
In addition, the reversible rolling mill 1 tends to have a short time used for various setting changes in rolling because of repeated forward and reverse rolling. For this reason, it is preferable to start the operation of the clamp device body 6 in synchronization with the bender device 11. However, if there is a margin, the clamp device body 6 may be operated before the start of the operation of the bender device 11. good.

  In this way, the time from when the clamp operation is started by the operation start signal of the bender device until the set time 1 elapses is the first restraining force F1, and the set time 1 that is the first fixed time after the start of the clamp operation is the restraint. Press the chock sufficiently with the force 1 in the rolling horizontal direction. If the set time 1 is 2 seconds, it often ends before the start of rolling, and switches to the second restraining force F2 before the start of rolling. Thereafter, the second restraining force F2 remains during the set time 2 for a certain time from the rolling start signal.

  Here, when biting at the start of rolling, an impact load is received as a restraint reaction force. The impact load increases as the rolling load increases. When this impact load is large, there is a possibility that a choc bites into the housing due to temporary deformation of the rolling housing. In addition, it affects the life of the rolling mill 1 and the clamp device body 6 that receive the impact load. Moreover, since the reduction amount is also temporarily affected, it is not preferable from the viewpoint of rolling control. FIG. 3 shows an example of a time chart expected at that time.

  On the other hand, in this embodiment, the peak value P of the impact load can be kept small by temporarily lowering the restraining force to the second restraining force F2 when the rolled material is caught. As a result, the above problems are eliminated. While the second restraining force F2 is set, the first restraining force F1 is pressed in advance and R, so that the roll chock 4 displacement is restrained to the downstream side of the rolling and becomes a stable position. Thereafter, rolling starts and set time 2 starts. Note that FIG. 3 illustrates the case where the restraining force is temporarily reduced when biting, so the peak value P of the impact load is shown small. However, when the restraining force is not temporarily reduced, FIG. Seems to be a large impact load.

Further, when the set time 2 elapses, the restraining force 2 becomes as high as the third restraining force F3, so that the chock can be restrained reliably during rolling.
Here, in the restraint force controller 20, an estimated rolling load is input, and when the estimated rolling load is less than a predetermined value, the second restraining force F2 may not be switched (see FIG. 4).

Subsequently, when the set time 2 elapses from the start of rolling, the third restraining force F3 that can be restrained during rolling is changed.
Here, when it is estimated that the return of the restrained roll chock 4 is small, the second restraining force F2 may be changed to the third restraining force F3, that is, the restraining force may not be switched (see FIG. 5). For example, it is applied in the case of rolling conditions where the rolling horizontal load applied to the roll chock clamp device is large.
In this way, it is possible to effectively perform switching control by setting the rolling signal timing and the set time, and a stable roll chock clamping operation can be realized.

  As described above, according to the present embodiment, in the reversible rolling mill 1 in which the reversal of the forward / reverse rolling is quick, it is possible to easily operate the roll chock clamp device reliably, and the plate thickness deviation and the plate bending (camber). It is possible to use different sizes of restraining force or to change the operating time during rolling in the pass, depending on the rolling conditions that tend to occur, forward rolling and reverse rolling, etc. There is little interference with the thickness control device, and it is possible to obtain a rolled material having an excellent plate shape, which is extremely useful industrially.

(Second Embodiment)
Next, a second embodiment will be described. The same members as those in the first embodiment will be described with the same reference numerals.
The basic configuration is the same as that in the first embodiment, but the switching of the restraining force controlled by the restraining force controller 20 and the like are different combinations between forward rolling and reverse rolling.
The setting time of the switching timing of the binding force determined by the binding force controller 20 is also set to different setting times as the setting times 1a and 2a in the case of forward rolling and as the setting times 1b and 2b in the case of reverse rolling.

  That is, as shown in the time chart of FIG. 6, at the time of forward rolling, the third restraining force F3 is the same as the second restraining force F2, that is, switching to the third restraining force F3 is not performed. On the other hand, at the time of reverse rolling, the third restraining force F3 is set to a value larger than the second restraining force F2. When it is determined that the impact load at the time of biting is smaller than the predetermined value, it is not necessary to switch from the first restraining force F1 to the second restraining force F2, as shown in FIG.

(Action / Effect)
Also in this embodiment, before biting the thick steel plate to be rolled into the rolling mill 11, both the forward rolling and the reverse rolling are moved downstream by moving the roll chock 4 until it abuts against the shift block 5 by the first restraining force F1. Restrain to the side.
In the case of forward rolling, switching is made to the second restraining force F2 after the set time 1a has elapsed (for example, 2 seconds), and the restraining force during rolling remains the second restraining force F2 and is not switched. This is because, in the case of forward rolling, the horizontal component force applied to the roll chock 4 by rolling tends to be in the same direction as the restraint direction by the downstream side, that is, the roll chock clamp device, so the restraint force during rolling needs to be switched high. It is based on the judgment that there is no. That is, the rolling condition that can restrain the roll chock 4 to the downstream side from the load balance at the time of forward rotation even if the force is always lower than the first restraining force F1 that remains the second restraining force F2 during rolling. It is judged.

Also in the case of reverse rolling, the second restraining force F2 is switched after the set time 1b has elapsed (for example, 1.5 seconds). The setting time 2b is set to a few seconds (for example, 1 second) after the biting of rolling, and the third restraining force F3 is set during rolling when the biting is unsteady. In the case of reverse rotation, since the chock moves frequently upstream during rolling, it is necessary to reliably press with a restraining force that does not interfere with the plate thickness control device. The third restraining force F3 that is larger than the second restraining force F2 is switched.
In this way, it is possible to set a more appropriate restraining force by changing the restraining force by the roll chock clamp device according to the rotation direction of the work roll 3 and the plate passing direction during forward rolling and reverse rolling. It becomes.

(Third embodiment)
Next, a third embodiment will be described with reference to the drawings. In addition, about the structure similar to the said 2nd Embodiment, the same code | symbol is attached | subjected and demonstrated.
The basic configuration of this embodiment is the same as that of each of the above embodiments, but the switching of the restraining force by the restraining force controller 20 is slightly different.
Moreover, this embodiment is provided with a means for detecting the rotational acceleration of the work roll 3. The acceleration detecting means does not need to be a measuring device that outputs a continuous value of acceleration, and may be any device that can output an acceleration positive / negative determination. That is, in this embodiment, it is only necessary to be able to determine whether the work roll 3 is accelerating or decelerating. Moreover, since the normal rolling mill 1 is provided with the rotation speed meter of the work roll 3, as the acceleration detection means of the rotation of the work roll 3, the differential detector of a rotation speed meter and the variation | change_quantity of a rotation speed meter are used. It is also possible to use software that determines positive / negative.

In the restraint force controller 20, the basic restraint force switching pattern is the same as in the second embodiment, but differs in the following points.
That is, when it is determined that the work roll 3 has started to decelerate during forward rolling, the second restraining force F2 is changed to a third restraining force F3 larger than the second restraining force F2. If it is determined that the work roll 3 has started to decelerate during reverse rolling, the third restraining force F3 is changed to a second restraining force F2 that is smaller than the third restraining force F3.
Other processes are the same as those in the second embodiment.

(Action / Effect)
In consideration of the following, the third embodiment switches the restraining force during deceleration during forward rolling to a higher level and switches the restraining force during deceleration during reverse rolling to a lower level. It is possible to perform restraint with a more appropriate restraint force. FIG. 8 shows a time chart at that time.
That is, when the roll rotation, the rolling load, and the displacement of the roll chock 4 were investigated during the forward rolling and the reverse rolling in the reversible rolling mill 1 without the roll chock clamping device, as shown in FIGS. 9 and 10. There was a trend. The displacement of the roll chock 4 is obtained by measuring the relative displacement between the housing and the chock using a distance sensor embedded on the housing downstream side of the rolling mill 1.

  As shown in FIGS. 9 and 10, when the rotation of the roll is forward rotation acceleration and reverse rotation deceleration, the chock displacement is frequently located on the downstream side. On the other hand, when the rotation of the roll is forward deceleration and reverse acceleration, the chock displacement is frequently located at a position away from the downstream side. Therefore, in the roll chock clamping device that restrains the roll chock 4 in the forward rolling direction from the upstream side of the rolling mill 1, the reaction force from the chock is relatively small in the normal rotation acceleration and reverse rotation deceleration, and the normal rotation deceleration and reverse rotation acceleration. Therefore, it can be seen that it is effective to switch the restraining force necessary to restrain the roll chock 4 within a certain range. The reason why a higher restraining force is required is that there are many cases where the rotation of the work roll 3 is forward deceleration and reverse acceleration, and it is assumed that the chock moves frequently from the downstream side to the upstream side.

Here, the method of switching the restraining force of the roll chock clamping device only by detecting the acceleration of the rotation of the work roll 3 is more effective than the switching by setting the set time as long as the rolling acceleration is a stable acceleration / deceleration. . Alternatively, before the start of rolling, the roll chock 4 is clamped with the first restraining force F1, so that it is effective to use a combination of switching by setting the set time and switching the restraining force from rolling to the end of rolling by the rotational acceleration of the work roll 3. is there.
Depending on the rolling conditions, it may be sufficient to always clamp the roll chock 4 with the second restraining force F2 (see FIG. 11). In this case, if the setting of the restraining force is set to the second restraining force F2, it is possible to make the second restraining force F2 constant from the start of the operation of the chock clamp device by the start of the bender operation.

  At this time, when a pressing device using a hydraulic cylinder or the like is considered as the roll chock clamp device, the setting of the restraining force is based on the pressure setting from the pump supplied to the hydraulic cylinder. Therefore, when the restraining force is set low, the operating speed of the hydraulic cylinder due to the pressure is also reduced, and the time until the clamping device completes pressing the roll chock 4 toward the downstream side of the rolling mill 1 becomes long. Since it usually takes only a few seconds from the start of operation of the clamp device to before the start of rolling, there are cases where the second restraining force F2 cannot be sufficiently restrained. Therefore, even when the second restraining force F2 is sufficient during rolling, the restraining force of the clamping device before the start of rolling is the first restraining force F1, which is a roll choc to the downstream side at a certain speed with a certain force or more. It is better to restrain 4 by moving.

Here, in each of the above embodiments, the case where there is a pressing device such as the bender device 11 is illustrated, but the pressing device may not be provided. In the case where there is no such pressing device, the second restraining force F2 can be set to be smaller by the amount that the roll chock 4 is not restrained by friction during operation of the pressing device compared to the case where there is a pressing device. I can't.
Also, it can be used properly depending on the rolling conditions, with the balance between restraining the fluctuation of the roll chock 4 and the degree of interference with the plate thickness control device (AGC device), impact load of the clamp device, and wear, It is preferable to use in combination.
Each signal in the above can obtain the same result even if other timings corresponding thereto are referred to. For example, even if it is not an actual bender operation start signal or rolling start signal, the timing at which the monitor measurement value of the bender load or rolling load becomes a certain value or more may be referred to.

It is a schematic diagram which shows an example of the reversible rolling provided with the roll chock clamp apparatus which concerns on embodiment. It is a figure which shows the example of a time chart which concerns on 1st Embodiment. It is a figure which shows the relationship between restraint force and restraint force reaction force. It is a figure which shows another example of the time chart which concerns on 1st Embodiment. It is a figure which shows another example of the time chart which concerns on 1st Embodiment. It is a figure which shows the time chart which concerns on 2nd Embodiment. It is a figure which shows another example of the time chart which concerns on 2nd Embodiment. It is a figure which shows the time chart which concerns on 3rd Embodiment. It is a figure which shows the behavior of the roll chock at the time of forward rolling when there is no roll chock clamp apparatus. It is a figure which shows the behavior of the roll chock at the time of reverse rolling when there is no roll chock clamp apparatus. It is a figure which shows another example of the time chart which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reversible rolling mill 2 Backup roll 3 Work roll 4 Roll chock 5 Shift block 6 Clamp apparatus main body 11 Bender apparatus 20 Restraint force controller F1 1st restraint force F2 2nd restraint force F3 3rd restraint force a Gap | interval d Offset amount

Claims (7)

In a reversible rolling mill equipped with a roll chock clamp device that restrains the roll chock of the work roll in the direction along the rolling direction,
When the rolled material is restrained by applying a first restraining force to the roll chock before the rolled material bites into the work roll, and the collision load when the rolled material bites into the work roll is estimated to be larger than a predetermined value, rolling A method for producing a rolled material, wherein the setting is changed to a second restraining force smaller than the first restraining force before the material bites into the work roll. A clamping device main body for restraining the roll chock by applying a restraining force in the direction along the rolling direction to the roll chock of the work roll, and a restraining force controller for controlling the restraining force by the clamping device main body. A roll chock clamping device comprising:
The restraint force controller is
As the restraining force, the first restraining force for restraining the roll chock by moving it in the direction in which the backlash is eliminated, the second restraining force smaller than the first restraining force, and restraining the roll chock during rolling. The first restraining force is set before the rolling material bites into the work roll, and the first restraining force is set before the rolling material bites. A roll chock clamp device characterized in that the restraint force is set to 2 and the third restraint force is set when the biting of the rolled material is completed.   The second restraining force is set based on the estimated collision load that is expected to occur when the rolled material bites into the work roll. When it is determined that the rolling material is less than the predetermined collision load, the second restraining force is set to the first restraining force. The roll chock clamping device according to claim 2, wherein the second restraining force is set to a value smaller than the first restraining force when the value is equal to or greater than the restraining force of the first restraining force. .   When it is determined that the work roll is difficult to displace in the direction opposite to the direction in which the restraining force is applied by the clamping device body during rolling, the magnitude of the third restraining force is set equal to the second restraining force. The roll chock clamp device according to claim 2 or 3, wherein In the reversible rolling mill, the work roll axis is offset in the rolling forward direction from the backup roll axis, and the clamping device body is restrained by pressing the roll chock in the rolling forward direction,
The restraint force controller sets the third restraint force smaller than the first restraint force when rolling in the forward rolling direction, and the third restraint force when rolling in the direction opposite to the forward roll direction. The roll chock clamp device according to any one of claims 2 to 4, wherein the force is set equal to the first restraining force. In the reversible rolling mill, the axis of the work roll is offset in the rolling forward direction from the axis of the backup roll, and the clamp device body restrains the roll chock in the rolling forward direction,
A work roll rotation speed detection means and acceleration detection means,
When the restraint force controller determines that the work roll is rotating in the forward direction of rolling and decelerating or rotating in the reverse direction of rotation and accelerating, the third restraining force is set equal to the first restraining force 1 and the work roll is in the forward direction of rolling. In the rotation and acceleration rotation or rolling reverse rotation and deceleration rotation, the third restraining force is equal to or smaller than the second restraining force. The roll chock clamp apparatus described in any one of 4. The reversible rolling mill includes a pressing device that presses the rolling roll in a direction along the rolling direction,
The roll chock clamp device according to any one of claims 2 to 6, wherein the operation start of the load of the first restraining force is before the operation of the pressing device or at the same time.

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