JPH04351213A - How to change rolling roll cross angle and roll bending force during running - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for changing the rolling roll cross angle and bending force in a cross roll rolling mill during rolling operation.

0002

[Prior Art] A roll cross type rolling mill is used in which the roll axes of an upper work roll, an upper backup roll, and a lower work roll, a lower backup roll are made non-parallel, that is, intersect at an appropriate angle. A plate shape control device for modifying the shape of the crown or flatness is known (Japanese Patent Publication No. 35325/1983). In such conventional equipment, prior to the start of rolling, the material of the coil to be rolled, dimensional specifications such as plate width, plate thickness, input side plate crown, output side plate crown target value, rolling load, flatness target value, etc. Based on the data, calculate the optimal roll cross angle, make initial settings, and after the start of rolling, calculate the actual values of exit side plate crown, exit side flatness, etc., and maintain these within the allowable range of target values. The configuration is such that the roll cross angle is corrected and controlled.

By the way, with the above-mentioned conventional apparatus, there is no problem when manufacturing a single type of finished coil from a single type of base material coil, but if the coils are sequentially attached to the tail of the preceding coil. In cases where the top of the trailing coil is welded and many types of coils are continuously rolled, or 1
When changing the running plate thickness in the middle of one base material coil to obtain two different finished product thicknesses, the succeeding coil is rolled in succession to the preceding coil, so the optimal Although the initial setting of the roll cross angle is possible, the initial setting cannot be made for the trailing coil, and there is a problem that the conventional method cannot be directly applied to such continuous rolling.

[0004] Therefore, the present inventors devised a rolling roll cross angle changing device that solves the above-mentioned problems (Japanese Patent Application No. 2-296767). This running roll cross angle changing device is used on the cross roll type rolling machine during the process of continuously rolling the leading coil and the trailing coil connected thereto.
In the rolling roll cross angle changing device that changes the angle between the roll axes of the lower work roll and backup roll pair, the timing to change the roll cross angle setting is instructed to match the timing when the connecting portion of both coils passes through the rolling mill. During the rolling operation, the roll cross angle can be changed according to the dimensions of each of the plurality of target coils that are continuously fed.

[0005]

[Problem to be Solved by the Invention] When changing the roll cross angle as described above, the period from the start of changing the roll cross angle setting to the end of the change is a transitional state of the roll cross angle setting, so it is necessary to change the roll cross angle appropriately. A good plate crown and flatness cannot be obtained. However, due to constraints on the mechanical structure of the equipment, changing the roll cross angle requires a certain amount of time.
The time required for such a setting change is several seconds in the case of a long time. If it takes several seconds to change the settings in this way, assuming the standard rolling speed of a roll cross rolling mill, a defective part of 20 to 30 m in product plate length will occur, which will reduce the product roll. There was a fear that this could have a major impact on the city.

The present invention has been developed in view of the above circumstances, and provides a running method that suppresses the occurrence of defective portions and improves product yield between the start and end of changing the setting of the roll cross angle. An object of the present invention is to provide a method and device for changing the roll cross angle and roll bending force.

[0007]

[Means for Solving the Problems] The first method for changing the rolling roll cross angle and roll bending force according to the present invention is to change the rolling roll cross angle and roll bending force in the process of continuously rolling a leading coil and a trailing coil connected thereto. A rolling roll cross angle and roll bending force changing method for changing the roll cross angle and roll bending force set in a roll type rolling mill, the roll cross angle and roll bending force being changed in accordance with the timing when the connecting portions of both coils pass through the rolling mill. It is characterized by instructing the change timing of corner and roll bending forces.

Second running roll cross angle according to the present invention
The roll bend force changing method is a rolling roll cross angle/roll bend force changing method that changes the roll cross angle and roll bend force set in the cross roll rolling mill during rolling of the coil. It is characterized by instructing the timing to change the roll cross angle and roll bending force in accordance with the timing at which a specific point passes through the rolling mill.

The first rolling roll cross angle according to the present invention
The roll bending force changing device changes the roll cross angle and roll bending force set in the cross roll type rolling mill during the process of continuously rolling the leading coil and the trailing coil connected thereto. This is a corner/roll bending force changing device that calculates the change amount, which is the difference between the roll cross angle for the leading coil and the roll cross angle for the trailing coil, before the connecting portion of both coils reaches the rolling mill. roll cross angle change calculation means for calculating a roll bend force change pattern before the connection area of both coils reaches the rolling mill; a setting change timing instructing means for instructing the change timing of the roll cross angle and roll bending force in accordance with the timing of passing through the machine; and calculation of the roll cross angle change amount calculating means in accordance with the instruction timing from the setting change timing instructing means. A roll cross angle setting means for changing the set value of the roll cross angle based on the result, and an instruction timing from the setting change timing instruction means as a change start point, based on the calculation result of the roll bending force change amount calculation means. It is characterized by comprising a roll bend force setting means for changing a set value of the roll bend force.

Second running roll cross angle according to the present invention
The roll bending force changing device is a running roll crossing angle/roll bending force changing device that changes the roll crossing angle and roll bending force set in the cross roll rolling mill during rolling of the coil. A roll cross angle change amount calculation means for calculating the amount of change in the roll cross angle before the specific point reaches the rolling mill, and a roll cross angle change amount calculation means for calculating the change amount of the roll cross angle before the specific point in the longitudinal direction of the coil reaches the rolling mill. a roll bending force change amount calculation means for calculating a change pattern; a setting change timing instruction means for instructing the change timing of the roll cross angle and the roll bending force in accordance with the timing at which a specific point in the longitudinal direction of the coil passes through the rolling mill; roll cross angle setting means for changing the set value of the roll cross angle based on the calculation result of the roll cross angle change amount calculation means in accordance with the instruction timing from the setting change timing instruction means; The present invention is characterized by comprising roll bending force setting means for changing the set value of the roll bending force based on the calculation result of the roll bending force change amount calculation means, using the instruction timing as a change start point.

[0011]

[Operation] The roll cross angle and the roll bending force are controlled in order to control the shape of the coil to be rolled, but the shape control is mainly performed regularly by controlling the roll cross angle. In the first method of the present invention, in the process of continuously rolling the leading coil and the trailing coil connected thereto, the roll cross angle is adjusted in accordance with the timing at which the connecting portion of both coils passes through the rolling mill. and the timing to change the setting of the roll bend force.When changing the roll cross angle, the roll bend force is changed together with the roll cross angle, so while changing the roll cross angle, the roll cross angle and roll The shape of each coil is controlled by the bending force, and the lack of control amount of the coil shape control by the roll cross angle control, which has a relatively slow response, is replaced by the coil shape control by the roll bending force, which has a relatively quick response. supplemented by

[0012] In the second method of the present invention, the setting change timing is instructed in accordance with the timing at which a specific point in the longitudinal direction of the coil passes through the rolling mill. Even while the roll cross angle is being changed, the shape of the coil is controlled as described above using the roll cross angle and the roll bending force.

[0013] In the first device of the present invention, the first
When performing control as in the method described above, before the connecting portion of both coils reaches the rolling mill, the change amount of the set roll cross angle and the change pattern of the set roll bending force are calculated respectively, and based on the results of these calculations, Since the roll cross angle and the roll bending force are controlled by the following steps, the roll crossing angle and the roll bending force are changed while performing control that takes advantage of their respective control characteristics.

[0014] In the second device of the present invention, the second
When performing control such as the device described above, before a specific point in the longitudinal direction of the coil reaches the rolling mill, the change amount of the set roll cross angle and the change pattern of the set roll bending force are calculated, and the results of these calculations are calculated. Since the roll cross angle and roll bend force are controlled based on the above, the roll cross angle and roll bend force are changed while performing control that takes advantage of their respective control characteristics.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically explained below based on drawings showing embodiments thereof.

First, the principle of the present invention will be explained. The roll cross angle of the roll cross type rolling mill is determined for each coil to be rolled so that an optimal plate shape can be obtained. This roll cross angle is calculated as the roll cross angle equivalent to the required roll mechanical crown amount. Also,
It is well known that roll bending force has an effect equivalent to the amount of roll mechanical crown. Therefore, a relational expression for obtaining the optimum plate shape of the coil can be obtained between the roll cross angle and the roll bending force. This relational expression (hereinafter referred to as cross angle/bender optimum curve expression) is as follows (
1) It is as shown in the formula and is obtained for each coil.

a0 +a1 ・FW +a2 ・θ2 =0...(
1)

However, in the above formula (1), FW
is the roll bend force, θ is the roll cross angle, a0, a
1 and a2 are parameters determined for each coil.

As described above, the roll cross angle and the roll bending force are equivalent in terms of their effect on the plate shape, but the device for adjusting the roll cross angle and the device for adjusting the roll bending force are When viewed as a control actuator, there are the following major differences. That is,
The roll cross angle adjustment device has a wide control range for the plate shape, but its responsiveness is low, while the roll bend force adjustment device
There are differences in controllability, such as a narrower control range for the plate shape but higher responsiveness. Focusing on this difference in controllability, when changing the roll cross angle, the roll bend force is controlled by the roll bend force adjustment device between the start and end of the change, and the roll bend force is If the plate shape is controlled by the control, the plate shape can be controlled even from the start of changing the roll cross angle to the end of changing the roll cross angle.

FIG. 1 is a graph of a cross angle/bender optimum curve showing a method of controlling the plate shape from the start of changing the roll cross angle to the end of changing the roll cross angle, with the roll bending force on the vertical axis and the roll cross angle on the horizontal axis. Each represents these relationships. In the figure, A is the cross angle/bender optimum curve obtained from the cross angle/bender optimum curve equation for coil A, which is the preceding material, and B in the figure is the cross angle/bender optimum curve of coil B, which is the next material connected to coil A. This is the cross angle/bender optimum curve obtained from the cross angle/bender optimum curve formula.

Since the control range of the roll bending force is narrow, in order to widen the effective range, the roll bending force FMAX is set to 1/2 of the maximum value FMAX of the roll bending force.
It is assumed that a value near /2 is used. in this case,
The optimum control point for coil A is point PA, and the optimum control point for coil B is point PB. When shifting from control of coil A to control of coil B, coil A
At the connection point between coil B and coil B, the roll cross angle is θ
A is changed to θB, but since the speed of changing the roll cross angle is slow, the roll bending force is adjusted at this time. This adjustment of the roll bending force is carried out using the arrows in the figure so that the roll bending force exists on the cross angle/bender optimum curve A and the cross angle/bender optimum curve B according to changes in the value of the roll cross angle. Point PA →PA1→PB as shown in
Follow the route 1 → PB. However, the target cross angle
When changing the bender optimum curve from cross angle/bender optimum curve A to cross angle/bender optimum curve B, change from PA1 to P.
Immediately change the roll bending force significantly as shown in B1. In this way, when changing the roll cross angle, if you adjust the roll bend force according to the coil cross angle/bender optimum curve, the roll bend force will be adjusted to the optimum value except when changing the cross angle/bender optimum curve. Since the value is set to a value that allows a plate shape to be obtained, defects in the plate shape of the coil when changing the roll cross angle can be suppressed.

Next, a case will be described in which a device for controlling plate shape based on the above-mentioned principle is applied to a tandem mill consisting of five stands.

FIG. 2 is a block diagram of the rolling roll cross angle changing device according to the present invention, in which #1 to #5 represent the first to fifth stands, and A and B represent coils with different dimensions. It shows.

Among the five stands that make up the tandem mill, the first and second stands #1 and #2 use roll cross type rolling mills, and the third to fifth stands #3 to #5 use rolling mills. An ordinary rolling mill in which the roll axis is set perpendicular to the rolling direction is used. Coils A and B are coil A
The top of the coil B is welded to the tail of the coil B, and the coil B is connected in series so that it is continuously passed through a tandem mill from the direction of the white arrow and rolled. Each stand #1 to #5
Each of the rolling mill roll gap setting devices 11 to 15
, roll speed setting devices 21 to 25 of the rolling mill are provided,
In addition to these, the first and second stands #1 and #2 are further provided with rolling mill roll cross angle setting devices 31 and 32 and roll bending force setting devices 41 and 42, respectively.

[0025] Each of the roll gap setting devices 11 to 15
, the roll gap and roll speed for each stand #1 to #5 calculated by the roll gap/roll speed setting change amount calculation device 40 are stored in each of the roll speed setting devices 21 to 25, and each of the roll cross angle setting devices 31 and 32 are the set roll cross angles for each stand #1 and #2 calculated by the roll cross angle change amount calculation device 50, and each roll bend force setting device 41 and 42 is a roll bend force change amount calculation device. Each stand #1, # calculated at 80
The set roll bending force for each roll bending force is inputted in accordance with a timing instruction signal from a setting change timing instruction device 70, respectively.

The roll gap/roll speed setting change amount calculation device 40 and the roll cross angle change amount calculation device 50 calculate the roll gap/roll speed and roll for the next coil to be rolled based on the information taken in from the coil information transmission device 60. It is configured to calculate a cross angle. Further, the roll bend force change amount calculating device 80 calculates a roll bend force change pattern such as PA → PA1 → PB1 → PB in FIG. 1 based on the information taken in from the coil information transmission device 60.

The setting change timing instructing device 70 tracks the connection point (specific point) C between the coils A and B over the front and rear regions of the tandem mill, and tracks the connection point (specific point) C between the coils A and B, and
Each stand #1 to #5 immediately before reaching between the work rolls of
The roll gap and roll speed from the roll gap/roll speed setting change amount calculation device 40 are sent to the roll gap setting devices 11 to 15 and the roll speed setting devices 21 to 25, and the roll gap and roll speed are sent to the roll gap setting devices 11 to 15 and roll speed setting devices 21 to 25, and the roll gap and roll speed are sent to the roll gap setting devices 11 to 15 and roll speed setting devices 21 to 25, and the roll gap and roll speed are sent to the roll gap setting devices 11 to 15 and roll speed setting devices 21 to 25. Then, the roll cross angle from the roll cross angle change amount calculation device 50 is further calculated by the roll bend force setting devices 41 and 42.
In order to sequentially take in the roll bending force from the roll bending force change amount calculation device 80, timing signals are sent to each roll gap setting device 11 to 15, roll speed setting device 21 to 25, and roll cross angle setting device. 31
, 32 and roll bending force setting devices 41, 42.

These roll gap setting devices 11 to 15
, roll speed setting devices 21 to 25, and roll cross angle setting devices 31 and 32 output signals to an actuator for setting a roll gap, a roll drive motor, and an actuator for setting a roll cross angle (not shown), respectively, to set the roll gap and roll speed. , the roll cross angle is changed in a ramp-like pattern as shown in FIG. Further, the roll bend force setting devices 41 and 42 output signals to a roll bend force setting actuator (not shown),
According to the principle shown in FIG. 1, the roll bending force is changed in a pattern shown in FIG. 4.

FIG. 3 shows the timing at which the connection point C of the coils A and B reaches between the work rolls in the rolling mills of the stands #1 to #5 that make up the tandem mill, and the timing at which the connection point C of the coils A and B arrives, and
12 is a timing chart showing the relationship between the roll gap change timing and the rolling mills of the fifth stands #1 to #5. As is clear from this, each stand #1 to #5
For rolling mills, the roll gaps (ΔG1, ΔG2, ΔG3,
The modification of ΔG4, ΔG5) is started and ends after the modification time T.

Next, the relationship between the control timing of the roll gap and the control timing of the roll cross angle and roll bending force will be explained. The control timing of the roll cross angle and roll bending force is the same for each stand. Taking the first stand as an example, we will specifically explain the relationship between the control timing of the roll gap and the control timing of the roll cross angle and roll bending force. explain.

FIG. 4 is a timing chart showing the relationship between the control timing of the roll gap in the first stand and the control timing of the roll cross angle and roll bending force. If the operating time of the actuator for changing the roll gap, that is, the changing time is T, then the connection point C
The actuator is actuated to start changing the roll gap T/2 hours before C passes between the work rolls of the cross-roll rolling mill, and T/2 hours after the connection point C reaches between the work rolls. Change control of the roll gap is performed so that the change of the roll gap and roll speed is completed after a certain period of time. Further, the change in the roll cross angle starts before changing the roll gap and roll speed, and ends after changing the roll gap. In this case, the roll bending force is changed by changing the target cross angle/bender optimum curve from the cross angle/bender optimum curve A to the cross angle/bender optimum curve B at the start of the roll gap change. When the change of the roll gap is completed, the target cross angle/bender optimum curve is changed from cross angle/bender optimum curve A to cross angle/bender optimum curve B as described above. .

If the roll cross angle and roll bending force are changed at such timing, the roll bending force will supplement the plate shape control by the roll cross angle in controlling the plate shape of the coil when the roll cross angle is changed, and the roll cross angle will be changed. Defects in the coil plate shape when changing the cross angle can be suppressed.

Further, in the above embodiment, a case has been described in which the connection point C is tracked to detect the timing at which the work rolls are caught between the work rolls of each rolling mill in each stand #1 to #5, but the present invention is not limited to this. First, the connection point C may be appropriately detected by a sensor and a change timing instruction signal may be output.

[0034]

Effects of the Invention As described above, the first method and the first method of the present invention
In the above equipment, when the connecting portion between the leading coil and the trailing coil passes through the rolling mill, the roll cross angle of the cross roll type rolling mill is changed between the start and the end of the change. In addition to the control, the roll bending force is controlled, so the lack of control amount in coil shape control that is insufficient by controlling the roll cross angle is compensated for by controlling the roll bending force, so when changing the setting of the roll cross angle, The second method and the second apparatus of the present invention suppress the occurrence of defective shaped parts and improve the product yield. In this case, the present invention has excellent effects, such as being able to be carried out when a specific point in the longitudinal direction of the coil passes through a rolling mill.

[Brief explanation of the drawing]

FIG. 1 is a graph of a cross angle/bender optimum curve showing a plate shape control method from the start of changing the roll cross angle to the end of changing the roll cross angle.

FIG. 2 is a block diagram of a rolling roll cross angle changing device according to the present invention.

FIG. 3 is a timing chart showing the relationship between the timing at which the connection point of the coil arrives between the work rolls in each rolling mill of each stand that constitutes the tandem mill, and the timing of changing the roll gap for the rolling mill of each stand. .

FIG. 4 is a timing chart showing the relationship between the control timing of the roll gap and the control timing of the roll cross angle and roll bending force in the first stand.

[Explanation of symbols]

#1 to #5 First to fifth stands 11 to 15 Roll gap setting devices 21 to 25
Roll speed setting device 31, 32 Roll cross angle setting device 41, 42
Roll bend force setting device 40 Roll gap/
Roll speed setting change amount calculation device 50 Roll cross angle change amount calculation device 60 Coil information transmission device 70 Setting change timing instruction device

Claims (4)

[Claims] [Claim 1] In the process of continuously rolling a leading coil and a trailing coil connected thereto, a running roll cross angle and a roll bending force that change the roll cross angle and roll bending force set in a cross roll type rolling mill are used. A method for changing roll bending force, characterized in that the timing of changing the roll cross angle and roll bending force is instructed in accordance with the timing at which the connecting portions of both coils pass through a rolling mill. How to change force. 2. A rolling roll cross angle and roll bending force changing method for changing the roll cross angle and roll bending force set in a cross roll type rolling mill during rolling of a coil, the method comprising A method for changing the roll cross angle and roll bending force during running, characterized by instructing the timing of changing the roll cross angle and roll bending force in accordance with the timing when the roll passes through a rolling mill. 3. In the process of continuously rolling the leading coil and the trailing coil connected thereto, the rolling roll cross angle and the rolling roll cross angle and the roll bending force set in the cross roll type rolling mill are changed. A roll bending force changing device that calculates the change amount, which is the difference between the roll cross angle with respect to the leading coil and the roll cross angle with respect to the trailing coil, before the connecting portion of both coils reaches the rolling mill. A cross angle change amount calculation means, a roll bend force change amount calculation means for calculating a roll bend force change pattern before the connection portion of both coils reaches the rolling mill, and a roll bend force change amount calculation means for calculating a roll bend force change pattern before the connection portion of both coils reaches the rolling mill. a setting change timing instructing means for instructing the change timing of the roll cross angle and roll bending force in accordance with the passing timing, and a calculation result of the roll cross angle change amount calculation means according to the instruction timing from the setting change timing instructing means. and roll bending based on the calculation results of the roll bending force change amount calculation means, with the instruction timing from the setting change timing instruction means as a change start point. A running roll cross angle/bending force changing device characterized by comprising roll bending force setting means for changing a force setting value. 4. A running roll cross angle/roll bend force changing device for changing the roll cross angle and roll bend force set in a cross roll type rolling mill during rolling of a coil, the device comprising: a roll cross angle change amount calculating means for calculating the amount of change in the roll cross angle before the coil reaches the rolling mill; and a roll bending force change pattern for calculating the change amount of the roll cross angle before the coil reaches the rolling mill at a specific point in the longitudinal direction of the coil. a roll bending force change amount calculation means for calculating the change amount of the roll bending force; a setting change timing instruction means for instructing the change timing of the roll cross angle and the roll bending force in accordance with the timing at which a specific point in the longitudinal direction of the coil passes through the rolling mill; According to the instruction timing from the change timing instruction means,
Roll cross angle setting means changes the set value of the roll cross angle based on the calculation result of the roll cross angle change amount calculation means, and the roll bending force is adjusted based on the instruction timing from the setting change timing instruction means as a change start point. 1. A running roll cross angle/bending force changing device comprising: roll bending force setting means for changing a set value of roll bending force based on the calculation result of the change amount calculating means.