JPH105807A - Cold rolling method of metal sheet at shifting work roll during rolling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the variation of thickness and to stably execute a cold tandem rolling by enlarging the band width of a tension controlling means larger than at its regular rolling time and rolling from beginning of shifting of work rolls up to finishing. SOLUTION: The tension to be applied on a metal sheet 1 between a 1st stand 2 and a 2nd stand 3 during rolling is detected by a tension meter 4 installed between the 1st and 2nd stands, and a tension signal is inputting to a tension controller 4 with a TLC. In the tension controller 5, the inputted tension signal is compared with the upper limit and lower limit of a target value of the tension control, in the case of the detected tension being made out from the upper limit and lower limit of the target value, the command is emitted to a hydraulic draft device 6 of the 2nd stand 3. By the hydraulic draft device 6, the roll gap between upper and lower work rolls 3 is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling method in which a work roll is shifted in an axial direction during rolling, and more particularly to a cold rolling method in which a change in sheet thickness does not occur during the work shift. .

[0002]

2. Description of the Related Art When rolling a sheet material in a continuous rolling mill, rolling has been conventionally performed by shifting a work axis in an axial direction in order to reduce an edge drop generated at an end of the sheet. ing. This work shift is not performed merely for the purpose of reducing the edge drop, but is formed by a corner portion of the plate contacting the work. It is also used for the purpose of preventing the occurrence of edge marks on the roll and controlling the shape in the plate width direction.

[0003] In particular, when a work shift is applied for the purpose of reducing the edge drop, as disclosed in Japanese Patent Publication No. 60-51921, for example, one end of the work roll is used. A method such as processing the shape of the portion into a taper shape is employed.

[0004] In the case of applying rolling by a cold-roll shift to cold rolling, the cold rolling is generally a continuous rolling process in which a plurality of original coils (coils before cold rolling) are successively welded and connected. Therefore, it is necessary to perform a wheel shift during rolling, mainly in accordance with the width of the original coil to be rolled.

[0005] However, if the work shift is performed during rolling, a problem as disclosed in Japanese Patent Application Laid-Open No. 7-100502 occurs. That is, during the work shift, the plate material is formed on the surface of the work roll in a direction perpendicular to the axial direction (the feed of the grinding wheel during the roll grinding). Along with
The friction coefficient increases due to the oblique line with respect to the circumferential streaks that occur on the surface of the steel sheet, so that the thickness of the part of the original coil rolled during the work shift increases. It is.

In order to prevent such behavior, Japanese Unexamined Patent Publication No. Hei 7-100502 discloses a method in which a rolling speed is determined by using a shift speed determined by using at least one of a rolling speed and a surface roughness of a workpiece as a control factor. A method of rolling while shifting the roll is disclosed.

[0007] Regarding the increase in the coefficient of friction which causes the increase in the sheet thickness, a similar report has been made in a rolling method for crossing the upper and lower rolls (October 1992,
The 43rd Joint Lecture on Plastic Working, Lecture Paper II, "Load characteristics of cold cross-rolling of thin plates").

The phenomenon in such cross-roll rolling is the same as that in the case where the rolled material shifts during rolling in that the rolled material skews with respect to the grinding line on the surface of the roll. is there.

[0009]

However, the above-mentioned prior art has the following problems.

In other words, the present inventors applied a BISRA-AGC (BISRA type thickness control device) to a stand for performing a shift of a work roll during a rolling operation when shifting the work roll during rolling. When the control was performed, it was examined how the thickness of the sheet on the exit side of the stand for performing the wheel shift and the thickness of the sheet on the downstream side thereof changed.

FIG. 9 shows a 5-stand continuous cold rolling mill to which BISRA-AGC is applied as an automatic thickness control means in the first stand, and a sheet material is cold-rolled at a rolling speed of 45 m / min. FIG. 4 is a graph showing a change in rolling load and thickness of a rolled material over time when a work of a first stand having a surface roughness Ra of 1 μm is axially shifted at a shift speed of 2 mm / min. (A) shows the change in the distance between the center of the trunk of the upper and lower wheels of the first stand performing the shift and the center of the pass line (referred to as the shift shift position); (C) shows the change in the plate thickness on the exit side of the first stand, (d) shows the change in the plate thickness on the exit side of the second stand,
(E) is a graph which shows the change of board thickness on the exit side of the fifth stand which is the last stand, respectively.

As can be seen from FIG. 9 (b), in the first stand where the work shift is performed during rolling, a work is performed.
The rolling load increases only during the crawl shift.

The BISRA-AGC can prevent such an increase in the sheet thickness caused by the increase in the rolling load, and as shown in FIG. Thickness is controlled.

However, even if the plate thickness is kept constant in the first stand for performing the work shift,
Next, the second stand exit side plate thickness is reduced as shown in FIG. 9D while the first stand is performing the wheel shift, and due to the influence, the exit of the fifth stand which is the final stand is performed. As shown in FIG. 9E, the finished plate thickness on the side is also smaller by several μm to several tens μm than the target plate thickness.

The technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-100502 is intended to keep the thickness of the exit side of the stand performing the work shift shift constant. Cannot be kept constant.

Japanese Patent Publication No. 60-51921 does not disclose any measures against thickness fluctuation when performing a work-roll shift during rolling.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to prevent a variation in the finished plate thickness when performing a work roll shift during rolling. .

[0018]

SUMMARY OF THE INVENTION According to a first method of the present invention for performing a cold rolling of a sheet material during a rolling process during rolling, a method of forming a vertically rolling work piece on a cold rolled steel plate is described. Using a continuous cold rolling mill having a stand capable of shifting in the axial direction of the stand and tension control means for controlling the output side tension of the stand to be shifted by changing the roll gap of the next stand. In the cold rolling method for a sheet material in which a work roll shift is performed during the work roll shift, the band width of the tension control means for controlling the output side tension of the shifted stand is set to a value between the start and end of the work shift. -Rolling is performed with a band width larger than the band width at the time of steady rolling in which no shift is performed.

In addition, during the second rolling according to the present invention,
A cold rolling method of a sheet material to be subjected to a crawl shift is to use a stand capable of shifting a vertically positioned work roll in each axial direction and a delivery side tension of the shifted stand to a next stand. In a cold rolling method for a sheet material in which a work roll shift is performed during rolling using a continuous cold rolling mill having a tension control means for controlling by changing a roll gap, a work roll shift is started. During the period from the end to the end, the target value of the tension control of the tension control means for controlling the output side tension of the shifted stand is set to be higher than that at the time of steady rolling without performing the work shift.

In addition, during the third rolling according to the present invention,
A cold rolling method for a sheet material to be subjected to a crawl shift includes a stand capable of shifting a vertically positioned work roll in each of the axial directions, and a discharge side tension of the stand to a next stand. Using a continuous cold rolling mill with tension control means for controlling by changing the roll gap, in a cold rolling method for a sheet material in which a work roll shift is performed during rolling, the outlet side of a shiftable stand. The tension control is not performed while keeping the roll gap of the next stand constant from the start to the end of the work roll shift, and is performed by the roll gap control means during the steady rolling without the work roll shift. It is to be rolled.

In addition, during the fourth rolling according to the present invention,
A cold rolling method of a sheet material to be subjected to a crawl shift is to use a stand capable of shifting a vertically positioned work roll in each axial direction and a delivery side tension of the shifted stand to a next stand. Rolling is performed by using a continuous cold rolling mill provided with tension control means for controlling by changing the roll gap and BISRA type thickness control means for controlling the roll gap in the shiftable stand. In the cold rolling method for a sheet material in which a work roll shift is performed, the output side tension of the shifted stand is controlled by adjusting the roll gap of the shifted stand from the start to the end of the work roll shift by the BISRA type plate. At the time of steady rolling that is performed by controlling by the thickness control means and does not perform the work roll shift, rolling is performed while being performed by the tension control means. That.

In addition, during the fifth rolling according to the present invention,
A cold rolling method for a sheet material to be subjected to a crawl shift includes a stand capable of vertically shifting a work roll, which can be shifted in an axial direction, and a tension meter arranged on an outlet side of the shifted stand. In the cold rolling method for a sheet material in which a work roll shift is performed during rolling by using a continuous cold rolling mill provided with the above, the control of the output side tension of the shifted stand is completed from the start of the work shift. In the meantime, the rolling speed of the shifted stand is changed by changing the rotation speed. During steady rolling without performing work roll shift, the roll gap of the next stand is determined based on the tension signal from the tension meter. The rolling is performed while changing the rolling.

The present inventor has analyzed in detail the cause of the thickness variation when performing the work roll shift during rolling, and has found that the following mechanism is an essential cause. . In other words, when performing a work roll shift during rolling, the rolled material will be skewed relative to the grinding line on the roll surface, causing a change in the lubrication state of the roll bite, as well as the average value of the coefficient of friction, Due to the change in the distribution, the neutral point moves in the roll bite exit side direction, thereby increasing the tension between the stands in front of the stand, and concluded that this is the cause of the thickness variation. .

In general, the lubrication state in a roll tool during cold rolling is such that the lubricating oil film introduced at the tool inlet becomes thinner as the material elongates in the rolling direction, and the contact between the roll and the rolled material is reduced. Department is expanded. Therefore, at the roll bite inlet, fluid lubrication was dominant, but it is considered that the boundary lubrication area expands toward the roll bite outlet, and the rolled material is skewed relative to the grinding edge of the roll. It is believed that the impact of doing so will be closer to the roll bite exit, ie, more affected in the advanced zone.

FIGS. 10A and 10B are graphs showing the temporal change in the advance rate of the first stand for performing the wheel shift when the wheel shift is performed under the same conditions and timings as those described with reference to FIG. (B) is a graph showing a temporal change in the tension between the first and second stands (tension between the front stands), and (c) is a graph showing a temporal change in the tension on the first stand entrance side (rear tension). . As described with reference to FIG.
As shown in FIG. 10A, it is confirmed that the advance ratio has decreased during the shift, even though the plate thickness on the shift stand exit side is kept constant by the AGC. Further, as shown in FIG. 10C, the tension between the front stands is increased by about 10% as shown in FIG. 10B, although the rear tension is controlled to be substantially constant. I understand. It is a well-known fact that the increase in the tension between the front stands greatly affects the thickness of the exit side plate of the front stand (second stand). It was concluded that this was the mechanism of plate thickness variation when performing work roll shift.

That is, the thickness variation that occurs when performing a work roll shift during rolling is essentially caused by the movement of the neutral point toward the roll tool exit side due to the change in the lubrication state,
This is the increase in tension between the front stands, and BISR
This occurs even when the delivery side plate thickness of the shift stand is kept constant by means such as A-AGC.

Therefore, in order to reduce the variation in the thickness of the finished plate, it is necessary to reduce the tension in front of the shift stand.

A generally used tension control method called TLC (TLC, tension limit control)
(The tension is controlled by changing the roll gap of the next stand.) When the tension between stands deviates from the target value, the hydraulic pressure of the downstream stand is operated to The purpose is to bring the tension closer to the target value. For example, when the tension between the first and second stands is larger than the target value, the rolling reduction is increased by reducing the roll gap in the second stand, thereby increasing the material inflow speed on the second stand entrance side. , The tension control is performed by a method of reducing the tension between the first and second stands.

If the tension control by the TLC is applied to the case where the work shift is performed during rolling, the following problem occurs. That is, when the work roll shift is performed in the first stand, the tension between the first and second stands increases due to a change in the rolling state in the first stand, thereby decreasing the exit side plate thickness of the second stand. This is the cause of the plate thickness fluctuation. Therefore, when the above-described tension control by TLC is used, the plate thickness in the second stand is further reduced, which has an adverse effect.

As described above, in the conventional tension control, the thickness variation generated during the work roll shift is promoted. Therefore, in the present invention, the promotion of the thickness variation is prevented by the following method. The thickness variation was reduced to a level at which there was no practical problem.

Generally used tension control (TLC)
In, a certain band width is set with respect to the target value of the tension, and when the tension exceeds the band width, the lowering operation of the next stand is performed. Normally, a standard value of tension of about ± 5% is set as a band width for the purpose of performing tension control with high accuracy. Therefore, in the cold rolling method for a sheet material in which the work roll shift is performed during the first rolling according to the present invention, from the start to the end of the work roll shift,
The band width was expanded more than usual, and even if the forward tension fluctuated due to the work shift, the lowering operation at the next stand was not performed. Thereby, it is possible to prevent the thickness variation at the time of the work roll shift by the TLC from being promoted. In particular, since the tension in front of the shift stand is increased by the shift, a sufficient effect can be obtained by enlarging the positive side of the band width.

In the tension control by the normal rolling operation, it is also effective to increase the target value of the inter-stand tension control between the shift stand and the next stand only at the time of the work roll shift. This is to prevent the reduction operation by TLC from being performed when the forward tension increases due to the shift, as in the case of the increase in the bandwidth, and that the reduction in thickness promotes the variation in plate thickness. It has the effect of preventing.

Therefore, in the second cold rolling method for a sheet material in which the wheel shift is performed during the rolling according to the present invention, the target value of the tension control between stands is increased only during the wheel shift. It was.

The forward movement of the neutral point during the work roll shift is caused by a change in the lubrication state, and the rolling speed, the shift speed, the roll roughness and the viscosity of the rolling oil are the main influencing factors. is there. The movement of the neutral point, that is, the fluctuation of the advanced rate, becomes large as the rolling speed is low, the shift speed is high, and the roll roughness is large, and the amount of movement of the neutral point is the fluctuation of the tension between the front stands. There is a strong correlation with the amount. Therefore, by examining the relationship between the amount of tension fluctuation due to such shift, and the rolling speed, shift speed, and roll roughness, it is possible to appropriately change the tension target value according to operating conditions.

Further, it is also an effective means that the control by the TLC is not performed from the start to the end of the work roll shift. In this case, it is possible to prevent a phenomenon in which the TLC promotes a change in the sheet thickness during the work roll shift. However, in the meantime, the rolling operation is switched to the roll gap position control (keeping the roll gap constant) as in the cold rolling method of the plate material in which the roll shift is performed during the third rolling according to the present invention. Or BISRA-AG as in the fourth method of cold rolling a sheet material in which a work shift is performed during rolling according to the present invention.
It is necessary to perform reduction control using C. In particular, BISR
When used in combination with A-AGC, it is an even more effective means since it is possible to prevent a change in the thickness of the shift stand.

The normal tension control is performed by operating the reduction of the next stand by utilizing the high response of the hydraulic pressure reduction. However, only during the work roll shift during rolling, the work of the shift stand is performed. -Tension control can also be performed by changing the rotation speed of the crawl. For example, when the work roll shift is performed at the first stand, the forward tension (the tension between the first and second stands) increases. Therefore, the tension control is performed by changing the rotation speed of the work roll of the shift stand. By doing so, that is, reducing the rotation speed of the work roll of the first stand, it is possible to prevent the tension fluctuation between the first and second stands. By the way, in tension control in normal cold rolling, such a method is not taken because, compared to the response under hydraulic pressure, the response of roll speed change is low and the tension control with high response is performed. Because it is not possible,
Responsibility does not matter as long as this method is employed only during the shift.

Therefore, in the fifth cold rolling method for a sheet material in which a work shift is performed during rolling according to the present invention, the rotation speed of the work roll is changed only during the work shift. When the tension control is performed and the work shift is not performed, the roll gap of the next stand is changed on the basis of the tension signal from the tension meter to thereby reduce the thickness variation during the work shift. We tried to prevent it.

Incidentally, in order to prevent thickness fluctuation in tandem rolling, a technique of controlling tension is a general technique. However, the work roll shift operation, which is originally used for controlling a profile in the width direction of the sheet, is used. Correspondingly,
In order to prevent the thickness fluctuation caused by the disturbance,
There has been no method of changing the tension control parameter or control method between the start and end of the work roll shift.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cold rolling method for a sheet material in which a work shift is performed during rolling according to a first embodiment of the present invention is described below.
This will be described with reference to FIG.

FIG. 1 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to the present embodiment. The first acting on the sheet material 1 during rolling
The tension between the stand 2 and the second stand 3 is detected by a tension meter 4 provided between the first and second stands, and the tension signal is TL.
C is input to the tension control device 5. Then, the tension control device 5 compares the input tension signal with the preset upper and lower limits of the target value of the tension control, and when the detected tension is out of the upper and lower limits of the target value. Is issued to the hydraulic pressure reduction device 6 of the second stand 3, and the roll gap between the upper and lower wheels 3a of the second stand 3 is changed by the hydraulic pressure reduction device 6.

That is, when the detected tension exceeds the upper limit of the target value, the operation is performed so that the roll gap becomes smaller. As a result, the rolling reduction increases and the inflow speed of the material on the second stand 3 entry side decreases, so that the tension between the first stand 2 and the second stand 3 decreases.

If the detected tension is lower than the lower limit of the target value, the operation is performed so as to increase the roll gap. As a result, the rolling reduction decreases, and the inflow speed of the material on the second stand 3 entry side increases, so that the tension between the first stand 2 and the second stand 3 increases.

Then, the work 2 of the first stand 2
a is controlled by the wheel shift controller 7 during rolling.
When shifting in the axial direction, a work shift start signal is sent from the work shift control device 7 to the tension control device 5. The tension controller 5 changes the upper limit of the target value of the tension control to a larger value and the lower limit of the target value to a smaller value from the time when the work shift start signal is received. This change is continued until a signal indicating the end of the work shift is input from the work shift control device 7, and after the work shift is completed, the upper limit value and the lower limit value are returned to the original values.

FIG. 2 is a graph showing the upper limit and lower limit (the upper limit and the lower limit) of the target value of the tension control during steady rolling, in which the work is not shifted during rolling, when the shift is performed at the first stand. While the width between the lower limits is set to ± 5% of the standard value, the band width is -5% of the standard value from the start to the end of the work roll shift. (A) shows the variation of the plate thickness and the tension with time when the thickness is changed from + 30% to + 30%. (B) shows the band width in tension control, (c) shows the thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation at the exit side of the second stand, and (e)
Shows the thickness deviation on the exit side of the fifth stand which is the last stand, and (f) shows the change in the tension between the first and second stands. As shown in FIG. 2 (f), although the variation in tension between the first and second stands is not small as compared with the conventional method, the decrease in the thickness of the second stand at the exit side is as follows.
As shown in FIG. 2D, the thickness variation in the final stand is also reduced to a level at which there is no practical problem, as shown in FIG. 2E.

Next, a method of cold rolling a sheet material in which a work shift is performed during rolling according to a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 shows a cold rolling method for a sheet material in which a work shift is performed during rolling according to a second embodiment of the present invention.
It is a control system diagram for explaining. In FIG. 3, FIG.
The same components as those described in the above are denoted by the same reference numerals as those in FIG.
A detailed description thereof will be omitted. In this embodiment, the cold rolling method for a sheet material which performs a shift in rolling during rolling is the same as that described in FIG. Tension control between -2 stands is performed. When the wheel 2a of the first stand 2 is shifted in the axial direction by the wheel shift controller 7 during rolling, the wheel shift controller 7 sends the wheel 2a. A shift start signal is sent to the tension control device 5. In the tension control device 5, the target value of the tension control is increased between the first and second stands during the period from when the walk shift start signal is received to when the walk shift end signal is received. Perform tension control.

After the work shift is completed, the tension control is performed by returning the tension control target value to the original value.

Since the target value of the tension control during the shift differs depending on the shift speed, the rolling speed, the roll roughness, the viscosity and the concentration of the rolling oil, the optimum target value is determined by a test, and To calculate the optimum target value and input it to the tension control device 5.

FIG. 4 shows the setting of the target value of the tension control when the work shift is performed during rolling when the work shift is performed at the first stand. This shows the time-dependent fluctuation of the plate thickness and the tension when increased by 10% as compared with the time of steady rolling.
(A) is a change in the position of the vertical shift of the first and second wheels that perform the shift, and (b) a change in the target value based on the target value of the tension control during steady rolling. (C) is the thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation at the exit side of the second stand, and (e)
Shows the thickness deviation on the exit side of the fifth stand which is the last stand, and (f) shows the change in the tension between the first and second stands. As shown in FIG. 4 (f), although the tension fluctuation between the first and second stands cannot be reduced as compared with the conventional method, the decrease in the thickness of the second stand at the exit side is shown in FIG. 4 (d). As shown in FIG. 4 (e), the plate thickness variation in the final stand is also suppressed as shown in FIG.
It has been reduced to a level where there is no practical problem.

Next, a third embodiment of the present invention will be described with reference to FIG. 5.

FIG. 5 shows a cold rolling method for a sheet material in which a work shift is performed during rolling according to a third embodiment of the present invention.
It is a control system diagram for explaining. In FIG. 5, FIG.
The same components as those described in FIGS. 1 and 3 are denoted by the same reference numerals as those in FIGS. 1 and 3, and detailed description thereof is omitted. In this embodiment, the cold rolling method of the sheet material in which the roll shift is performed during the rolling is the same as that described with reference to FIGS. 1 and 3 at the time of the steady rolling in which the roll shift is not performed during the rolling. Thus, tension control between the first and second stands is performed. When the wheel 2a of the first stand 2 is shifted in the axial direction by the wheel shift controller 7 during rolling, the wheel shift controller 7 sends the wheel 2a. The shift start signal is sent to the tension controller 5 and the rolling position controller 8. In the tension control device 5, the control command to the hydraulic pressure reduction device 6 of the second stand is stopped until the work shift shift end signal is sent from the work shift control device 7. At the same time, the rolling position control device 8 controls the hydraulic pressure reducing device 6 so that the roll rolling position (roll gap) of the second stand 3 is maintained in the state immediately before the start of the work roll shift. Issue a command. That is, during the work shift, the first stand 2 and the second stand 3
In this state, the tension control is not performed.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 6.

FIG. 6 shows a method for cold rolling a sheet material according to a fourth embodiment of the present invention in which a work shift is performed during rolling.
It is a control system diagram for explaining. In FIG. 6, the same configuration as that described in FIGS.
The same reference numerals as in FIGS. 5 and 5 denote the same parts, and a detailed description thereof will be omitted. The cold rolling method for a sheet material in which a roll shift is performed during rolling according to the present embodiment is described as follows.
1, 3 and 5 during steady rolling without shift
The tension control between the first and second stands is performed in the same manner as described above. When the wheel 2a of the first stand 2 is shifted in the axial direction by the wheel shift controller 7 during rolling, the wheel shift controller 7 sends the wheel 2a. The shift start signal is sent to the tension controller 5 and the BISRA-AGC 10.
In the tension control device 5, the control command to the hydraulic pressure reduction device 6 of the second stand is stopped until the work shift shift end signal is sent from the work shift control device 7. At the same time, a command is issued from the BISRA-AGC 10 to the hydraulic pressure reduction device 11 of the first stand 2 only during this time so that the roll gap of the work roll in the first stand 2 is kept constant.

Next, a fifth embodiment of the present invention will be described with reference to FIG.

FIG. 7 shows a cold rolling method for a sheet material in which a work shift is performed during rolling according to a fifth embodiment of the present invention.
It is a control system diagram for explaining. 7, the same components as those described in FIGS. 1, 3, 5, and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the cold rolling method of the present embodiment, in which the workpiece is subjected to the work shift during rolling, the work 2a of the first stand 2 is controlled by the work shift control device 7 during the rolling. When shifting in the axial direction, a work shift start signal is sent from the work shift control device 7 to the tension control device 5. In the tension control device 5,
The tension control by the hydraulic pressure reduction device 6 is stopped at the time when the work shift start signal is received. And wow
While the crawl shift is being performed, the tension control device 5 operates based on the tension signal from the tension meter 4 to control the work of the first stand 2.
The number of rotations of the drive motor 12 of the crawler 2a is changed to control the tension between the first and second stands until the wristle shift control unit 7 receives a work shift end signal. Do. Then, after the end of the work shift, the control returns to the tension control by the hydraulic pressure reducing device 6.

FIG. 8 is a graph showing that the tension control is applied to the hydraulic pressure reduction device 6 of the second stand 3 during steady rolling without performing the wheel shift during rolling in the case of performing the wheel shift in the first stand. During the period from the start to the end of the work roll shift, the work roll shifter 2a of the first stand 2 is used.
(A) shows the variation with time of the plate thickness and the tension when the rotation speed of the driving motor 12 is changed.
Is the position of the upper and lower wheel shifts of the first stand which performs the shift, and (b) is the change in the rotation speed based on the rotation speed of the wheel during steady rolling. (C) is the sheet thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation at the exit side of the second stand, and (e)
Shows the thickness deviation on the exit side of the fifth stand which is the last stand, and (f) shows the change in the tension between the first and second stands. As shown in FIG. 8 (f), the variation in tension between the first and second stands is smaller than in the conventional method, and the decrease in the thickness of the second stand outlet side plate is shown in FIG.
As shown in FIG. 8D, the plate thickness variation in the final stand is also reduced to a level at which there is no practical problem as shown in FIG.

[0057]

According to the present invention, since the parameters and the control method relating to the tension control are changed from the start to the end of the work roll shift, the thickness variation can be prevented, and the cold tandem can be stably performed. Rolling can be performed.

[Brief description of the drawings]

FIG. 1 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to a first embodiment of the present invention.

FIG. 2 is a graph showing time-dependent fluctuations in sheet thickness and tension when a cold rolling method for a sheet material in which a work shift is performed during rolling according to the first embodiment of the present invention; (A)
Is the vertical shift position of the upper and lower wheels on the first stand which performs the shift, (b) is the band width in tension control, and (c) is the plate thickness at the exit side of the first stand. (D) is the sheet thickness deviation on the second stand exit side, (e) is the sheet thickness deviation on the fifth stand exit side that is the final stand, and (f) is the change in tension between the first and second stands. Are respectively shown.

FIG. 3 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to a second embodiment of the present invention.

FIG. 4 is a graph showing time-dependent fluctuations in sheet thickness and tension when a cold rolling method for a sheet material in which a work shift is performed during rolling according to a second embodiment of the present invention; (A)
Is the position of the vertical-wheel shift of the first stand that performs the shift, and (b) is the amount of change of the target value based on the target value of the tension control during steady rolling.
(C) shows the thickness deviation on the exit side of the first stand, (d)
Represents the thickness deviation on the exit side of the second stand, (e) represents the thickness deviation on the exit side of the fifth stand, which is the final stand,
(F) shows a change in the tension between the first and second stands, respectively.

FIG. 5 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to a third embodiment of the present invention.

FIG. 6 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to a fourth embodiment of the present invention.

FIG. 7 is a control system diagram for explaining a cold rolling method for a sheet material in which a work shift is performed during rolling according to a fifth embodiment of the present invention.

FIG. 8 is a graph showing time-dependent fluctuations in sheet thickness and tension when a cold rolling method of a sheet material in which a work shift is performed during rolling according to a fifth embodiment of the present invention is performed; (A)
Is the position of the upper and lower wheel shifts of the first stand which performs the shift, and (b) is the change in the rotation speed based on the rotation speed of the wheel during steady rolling. (C) is the sheet thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation at the exit side of the second stand, and (e)
Shows the thickness deviation on the exit side of the fifth stand which is the last stand, and (f) shows the change in the tension between the first and second stands.

FIG. 9 is a graph showing changes over time in rolling load and sheet thickness when a conventional cold rolling method for a sheet material undergoing a work shift during rolling is performed, and FIG. -Wheel of the upper and lower wheels of the first stand that performs the shift
(B) shows the change of the rolling load at the first stand, (c) shows the change of the sheet thickness at the exit side of the first stand, (d) shows the change of the sheet thickness at the exit side of the second stand, (E) is a graph which shows the change of board thickness in the exit side of the 5th stand which is the last stand.

FIG. 10 is a graph showing the change over time in the advance rate and the tension over time when a conventional cold rolling method for a sheet material undergoing a work shift during rolling is performed, and FIG. (B) shows the change in the advance rate of the first stand that performs
2C is a graph showing a change in tension between two stands, and FIG. 3C is a graph showing a change in tension on the first stand entrance side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate material 2 1st stand 2a work roll 3 2nd stand 3a work roll 4 Tension meter 5 Tension control device 6 Hydraulic pressure reduction device of 2nd stand 7 Word roll shift control device 8 Reduction position control device 9 Computer 10 BISRA-AGC 11 Hydraulic pressure lowering device for 1st stand 12 Motor for driving 1st stand-walk

Claims (5)

[Claims] 1. A stand capable of vertically shifting a work roll which is disposed to face each other in the axial direction, and changing the output side tension of the shift stand by changing the roll gap of the next stand. In a cold rolling method for a sheet material in which a work roll shift is performed during rolling using a continuous cold rolling mill provided with a tension control means for controlling, a shift is performed from the start to the end of a work roll shift. Wherein the band width of the tension control means for controlling the output side tension of the stand is set to be larger than the band width at the time of steady rolling without performing the work shift, and the work roll shift is performed during rolling. Cold rolling method of the sheet material to be performed. 2. A stand which can vertically shift a work roll which is disposed to face each other, and a stand which can shift in an axial direction, and an output side tension of the shift stand is changed by changing a roll gap of a next stand. In a cold rolling method for a sheet material in which a work roll shift is performed during rolling using a continuous cold rolling mill provided with a tension control means for controlling, a shift is performed from the start to the end of a work roll shift. The work roll shift is performed during rolling, wherein the target value of the tension control of the tension control means for controlling the output side tension of the stand is set to be higher than that at the time of the steady rolling without the work shift. The cold rolling method of the plate to be performed. 3. A stand capable of vertically shifting a work roll which is arranged to face each other in an axial direction, and controlling an output side tension of the stand by changing a roll gap of a next stand. In a method of cold rolling of a sheet material in which a work roll shift is performed during rolling using a continuous cold rolling mill having a tension control means for controlling the output side tension of a shiftable stand, -Rolling is performed while the roll gap of the next stand is not fixed from the start to the end of the roll shift, and rolling is performed by the roll gap control means during the steady rolling without performing the work roll shift. A cold rolling method for a sheet material during which a work roll shift is performed. 4. A stand capable of vertically shifting a work roll, which is disposed opposite to each other, in a respective axial direction, and changing an output side tension of the shift stand by changing a roll gap of a next stand. A continuous cold rolling mill equipped with a tension control means for controlling and a BISRA type thickness control means for controlling a roll gap in the shiftable stand is used to perform a work roll shift during rolling. In the cold rolling method, the output side tension of the shifted stand is controlled by adjusting the roll gap of the shifted stand from the start to the end of the work shift by the BI.
Cold rolling of a sheet material that performs a work roll shift during rolling is controlled by the SRA type sheet thickness control means and is rolled while being performed by the tension control means during steady rolling without performing a work roll shift. Method. 5. A continuous cold-roll system comprising a stand capable of vertically shifting a work wheel arranged in an opposed relation to each other in an axial direction, and a tension meter arranged on an outlet side of the shifted stand. In a cold rolling method for a sheet material in which a work roll shift is performed during rolling using a rolling mill, the control of the output side tension of the shifted stand is performed during a period from the start to the end of the work shift. At the time of steady rolling without changing the work roll shift, the rolling is performed by changing the roll gap of the next stand based on the tension signal from the tension meter. A cold rolling method for a sheet material, wherein a work roll shift is performed during rolling.