JPH0375242B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a meandering control device for a rolled material that is applied to a rolling mill that rolls a heated metal ingot, such as a hot strip mill or a plate mill.

[Prior art] A typical method of conventional meandering control for rolled material is to indirectly control the meandering amount of rolled material by the difference in output signals of load cells installed on the working side and drive side of a rolling mill. There is a system in which meandering is controlled by detecting the signal and adjusting the amount of reduction in the work side and drive side reduction systems based on the signal.

However, in this conventional method, the change in the load acting on both load cells due to the meandering of the rolled material is very small (although it varies depending on the rolling mill, a difference between the left and right sides of 1 ton or less must be considered);
Although it is theoretically possible to implement this method, it has been extremely difficult to put it into practical use due to the presence of disturbances due to rolling in the meandering control.

To explain in detail, first, we will look at the meandering mechanism of rolled material. When rolling a rolled material in a rolling mill, there are differences in hardness in the width direction of the material, taper in the width direction, etc.
Factors required for the rolled material itself, and the center of the rolled material is deviated from the center of the roll (off-center)
Due to such operational factors, an imbalance occurs in the rolling loads applied to the working side and the driving side of the rolling mill, resulting in a difference in the roll gap between the working side and the driving side. Therefore, the drawing speed of the material at the entrance side of the rolling mill is faster on the side where the gap is enlarged.
As a result, the rolled material is tilted at the entry side as if swinging its tail toward the wider gap side with respect to the advancing direction (arrow direction), as shown in Fig. Since the rolled material a moves at right angles to the axis of the roll, the rolled material a causes a lateral shift in the direction in which the roll gap is expanding, and the gap continues to expand.
The state of the gap at this time is as shown in FIG. Once the rolled material starts meandering like this,
It becomes impossible to recover to a stable state.

As mentioned above, the working side and drive side (hereinafter referred to as
If there is a difference in the roll gap between the left and right sides, the rolled material will begin to meander, so it can be seen that in order to prevent meandering, it is necessary to control the roll gap on the side where the rolled material is closer. .

Based on this concept, an example of a method shown in FIG. 3 is already known as a method for preventing meandering of a rolled material.

That is, the piston positions in the cylinders c and c' for roll reduction are detected by cylinder position detectors d and d' that detect the piston positions of the left and right hydraulic cylinders c and c', and the values are added to the summing amplifiers e and e. ′, and the outputs of summing amplifiers e and e′ drive servo valves f and f′ to control the left and right roll positions. It is not possible to correct the difference in the roll gap between the left and right sides due to the difference in bending or deformation of the left and right rolls caused by the movement in the direction of The difference between the left and right load detection signals obtained from the installed load cells g and g' is determined by an adder h, and the feedback amount is adjusted by a coefficient unit i so that the roll gap on the side where the load is increased is sandwiched. By applying signals to the summing amplifiers e and e' and appropriately adjusting the coefficient i, the roll gap can be controlled so as to return the widthwise position of the rolled material a toward the center of the roll. j is the upper and lower back-up rolls.

[Problems to be Solved by the Invention] However, although the method shown in FIG. In addition to the problem of the intervention of external disturbances, there are also theoretical difficulties as described below, which have prevented it from being put into practical use.

The difficulty will be explained with reference to FIG. FIG. 4A shows how the rolled material meandered and loads P _L and P _R were generated. If the rolling force P _R after the load increases is further increased and rolling control is performed to further reduce P _L , the roll gap on the _PR side will narrow and the meandering can be corrected. However, if the amount of increase in the load difference is insufficient at this time, the difference in the width direction of the roll gap will decrease as shown in Figure 4B.
Although the progress of meandering is weakened, it is not possible to create a gap difference sufficient to prevent meandering. On the other hand, if the load difference is too large, the fourth
As shown in Figure C, a roll gap difference is created to return the direction of the rolled material a to the center of the rolls, but because of this, the rolled material a rapidly approaches the P _L side, and if the control device cannot respond quickly enough, As it is, the roll goes too far from the center of the roll, goes too far to the P _L side, and then conversely goes too far to the _PR side, causing a vibrational meandering. Therefore, in this case, it is necessary to provide an appropriate difference between the left and right roll gaps so that the meandering of the rolled material a is not corrected too rapidly.

In other words, with control that calculates the left-right roll gap difference from the load difference and corrects the left-right roll gap difference, it is ineffective if the correction amount is insufficient, and control becomes unstable if it becomes too large. The appropriate amount must be corrected. However, this appropriate amount changes depending on conditions such as sheet width, thickness, material, and rolling speed, and there is no way to directly capture these effects, so it is difficult to determine the appropriate amount for all conditions. Setting the amount of correction is extremely difficult in practice.

In this way, the above method could not be put to practical use even though its effectiveness could be demonstrated in experimental rolling where conditions could be set constant.

In view of the above-mentioned circumstances, the present invention prevents the meandering of the rolled material, eliminates problems such as rolling stoppage, damage to the edges of the rolled material, and plate breakage, thereby stabilizing rolling and improving production. This method aims to improve efficiency and product yield, but the drawbacks of the method shown in Figure 3 are:
In other words, it overcomes the practical difficulties caused by the inability to correlate load differences with roll gaps.

[Means for Solving the Problems] The present invention provides a rolling mill for rolling heated metal ingots, in which light is imaged at approximately equal intervals in the width direction of the rolled material on the working side and drive side of the entry side of the rolling mill. A detector is provided that has a large number of image pickup elements and is capable of detecting the end position of the rolled material based on the radiation light emitted by the rolled material, and the meandering amount of the rolled material is determined from the difference in output signals of each detector. and a setting device for giving the target position of the rolled material, and a device for comparing and calculating the output signal of the computing device and the target signal of the setting device, and processing the signal obtained by the device. The roll gap of the working side and the driving side is changed by means of the rolling reduction correction signal.

[Function] The meandering amount of the rolled material is determined from the detected end position of the rolled material, the rolling correction signal on the work side and the driving side is determined from the difference between the meandering amount and the target value, and the rolling correction signal is calculated based on the rolling correction signal. First, the roll gap on the work side and drive side is corrected to eliminate the amount of meandering.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 5 shows an embodiment of the device of the present invention,
Upper and lower work rolls 1 and 2, upper and lower back up rolls 3 and 4, and a lower back up roll yoke 5 that supports both shaft ends of the back up roll 4.
6. Hydraulic rolling mill 1 equipped with hydraulic cylinders 7 and 8 that apply rolling force to the lower back up roll jocks 5 and 6, and configured to roll a rolling material 9.
At 0, the flow flows into the left and right hydraulic cylinders 7 and 8,
The pressure oil flowing out is controlled by the servo valves 11 and 12, and the hydraulic cylinders 7 and 8
Displacement detector 13, 1 detects the movement of the piston of
4 is attached to the hydraulic cylinders 7, 8, and the signals from the displacement detectors 13, 14 and the reduction correction signal 2, which will be described later, are
Addition amplifiers 15 and 16 are provided to compare the signals No. 3 and 24. The left and right roll gaps are servo valves 11 and 1.
2, by controlling the amount of pressure oil flowing into and out of the hydraulic cylinders 7 and 8,
Changes in the roll gap are detected by displacement detectors 13 and 14 that detect the movement of the pistons of the hydraulic cylinders 7 and 8.
measured indirectly by the summing amplifiers 15, 16.
This is compared with the reduction correction signals 23 and 24, and if there is a difference, the correction is made by controlling the servo valves 11 and 12 using the difference.

Detectors 17 on the left and right sides of the entrance side of the rolling mill 10 detect the width end position of the rolled material 9 based on the light emitted from it.
The difference between the signals from the respective detectors 17, that is, the meandering amount of the rolled material 9, is determined by the calculator 18, and the meandering amount is compared with the target signal from the setting device 19, etc.
0, and the obtained meandering amount deviation signal 22 is processed by a meandering control regulator 21 and applied to the addition amplifiers 15, 16 as left and right reduction correction signals 23, 24. For example, when the rolled material 9 moves toward the working side W, the output of the regulator 21 is directed to tighten the roll gap on the working side W and open the roll gap on the driving side D; If the difference occurs, the direction is determined and applied to the summing amplifiers 15 and 16 so that the roll gap is controlled in the opposite way to the above.

Therefore, the summing amplifiers 15 and 16 compare the actual displacement signals of the pistons of the hydraulic cylinders 7 and 8 with the reduction correction signals 23 and 24, and the servo valves 11 and 12 adjust the displacement of the hydraulic cylinders 7 and 8 based on the difference signal. As a result, the left and right roll gap is changed, and the mechanism described above prevents the meandering from progressing any further, and the rolled material 9 reaches the target given by the setting device 19. returned to the value.

The setting device 19 that provides the target position of the rolled material may be configured to store the initial biting position of the rolling material 9 in the rolling mill 10 as a memory and provide it as a control target, or to set the rolled material 9 at any arbitrary position in the width direction of the rolling mill 10. The configuration may be such that the settings can be changed freely so that the position can be passed through.

FIG. 6 shows details of the detector 17.
In the detector 17, the radiant light emitted from the rolled material 9 itself passes through a lens 26 provided in the intake section 25.
The light is guided onto a group of photoelectric conversion elements (image sensors) 27 arrayed in the width direction of the plate, and charges corresponding to the light energy are accumulated in the elements that receive the light.
By sequentially reading out this charge from the element group 27 and outputting an electric signal corresponding to the amount of charge, a video signal 28 as shown in FIGS. 7 and 8 is obtained.

Since the position in the element group 27 of the width end position of the rolled material 9 can be known from the rising portion of this video signal 28, the position of the end of the rolled material in the field of view can be determined as follows. .

Now, if the driving side is represented by D and the working side is represented by W, then the sixth
In the figure, the width end positions d _D and d _W of the rolled material 9 are as follows: d _D = X _D - _{C D} () d _W = X _W - _{C W} ().

Here, d _D , d _W ; distance from the optical axis 29 of the lens 27 to the width end position of the rolled material 9 ; X _D , X _W ; plate end lengths detected by the detector 17 C _D , C _W ; Field of view length L _D by element group 27, half _of L _W Note that in contrast to FIG. This is because it is necessary to know whether the rolled material 9 has shifted to the working side W, and in this example, the case where the rolled material 9 has shifted to the working side W is considered as a positive value, and the case where it has shifted to the driving side D is considered a negative value.

When the total number of elements in the element group 27 is N bits, α _D = L _D /N () α _W = L _W /N () is the resolution of the detector 17, and therefore, the rolling material 9
The number of light-receiving elements N _D , which received light from the X _D , X _W portions of
When N _W is determined, X _D and X _W become X _D = N _D × α _D ………() X _W = N _W × α _W ……… ().

From the above formulas () to (), the center P of the rolled material 9
The amount of deviation ( _meandering amount) ΔX from the machine center O can be obtained from ΔX=X _W − I can see what you are doing.

Arithmetic processing for determining the meandering amount ΔX is performed by the calculator 18 shown in FIG. 5 based on the video signal 28, and meandering control is performed based on the determined meandering amount ΔX.

The method of this meandering control will be specifically explained below.

In FIG. 5, the rolled material 9 advances in the direction of arrow A, passes below the detectors 17 installed on the left and right sides of the entrance side (work side W and drive side D) of the rolling mill 10, and passes through the rolling mill 10. bite into. After the rolled material 9 is caught in the rolling mill 10, the operator manually turns on a switch (not shown) to start the meandering control, or the meandering control is automatically started by a starting device (not shown). Control is then started.

When the meandering control starts, the left and right edge positions of the rolled material 9 detected by the left and right detectors 17 are added to the calculator 18 from time to time, and the meandering amount ΔX of the rolled material 9 is calculated by the formula (). In the case of FIG. 5, the calculation is made so that the case where the rolled material 9 is shifted to the left side, that is, to the working side W in the direction of movement of the rolled material, is given a positive sign.

The obtained meandering amount ΔX is sent to the comparator 20 and compared with the output of the setting device 19, that is, the target value for meandering control. Specifically, the calculation (target value - meandering amount) is performed. The target value given by the setter 19 is 0 volts because, for example, when the rolled material 9 is to be passed through the center of the machine in the width direction, the meandering amount is to be set to zero.
Then, as long as the rolled material 9 does not pass through the center of the machine, the comparator 20 outputs the meandering amount deviation signal 2.
2 occurs. Now, suppose the meandering amount ΔX is on the work side W.
Assume that the adjustment is made so that a voltage of 10 volts is generated when the drive side is shifted by 50 mm, and a voltage of -10 volts is generated when the drive side D is shifted by 50 mm. Therefore, if the output of the calculator 18 is +2 volts, the amount of meandering and the voltage are in a proportional relationship, so the rolled material 9 is on the working side W, 50 (mm) x 2 (V) / 10 (V) = This means that it is off by 10 (mm).

If the output of the calculator 18 is 2 volts and the output of the setting device 19 is 0 volts, then the comparator 2
The output of 0 will be 0-2=-2 volts. This is,
It is sent to regulator 20, where it is multiplied by a set gain. The regulator 21 includes, for example,
The gain is set to a value that changes the roll gap by 10 μm if the winding meandered by 1 mm, and a -2 volt signal is sent from the comparator 20, so 10 (μm/mm) x 50 (mm) x Rolling correction signal 2 that changes the roll gap by (-2) (V)/10V = -100 (μm)
3 and 24 are sent to addition amplifiers 15 and 16. This is converted into a voltage signal. For example, if the output of the displacement detectors 13 and 14 is manufactured so that 1 mm corresponds to 10 volts, then 1 mm
= 1000 μm, so a voltage of 10 (V) x (-100) (μm)/1000 (μm) = -1 (V) is sent to the summing amplifiers 15 and 16.

The summing amplifier 15 compares and calculates the command signal of the lowering control system on the driving side D side with the output of the displacement detector 13 that detects the actual piston position of the hydraulic cylinder 7 to obtain a deviation. Similarly, the summing amplifier 16 calculates the deviation by comparing the command signal of the rolling control system on the work side W side where the rolled material 9 is deviated with the output of the displacement detector 14 that detects the piston position of the hydraulic cylinder 8. demand.

The amount of change in the roll gap for correcting the meandering of the rolled material 9 is determined by the reduction correction signal 2 from the regulator 21.
3, 24, and in FIG. 5, the working side W
The output 24 of the summing amplifier 16 on the side D is multiplied by a negative sign, and on the contrary, the summing amplifier 1 on the drive side D side
5, the output 23 is added as is. Specifically, 1 volt is applied to the summing amplifier 16 from (-1)(V)×(-1)=1(V), and −1 volt is applied to the summing amplifier 15.

Now, the sign is determined so that when the command signal of the rolling control system on the left and right sides of the rolling mill 10 is positive, the roll gap is narrowed, and on the other hand, when it is negative, it is widened. Then, in the reduction control system on the work side W, +
so that the deviation of 1 volt = 100 μm is eliminated (the displacement detector 14 detects a signal equivalent to 100 μm,
The servo valve 12 is driven so that the output of the summing amplifier 16 becomes zero), and the piston of the cylinder 8 is lifted. On the other hand, in the driving side D side pressure reduction control system, the servo valve 11 is
is driven, and the piston of the hydraulic cylinder 7 is lowered. When the displacement detector 13 detects a signal equivalent to a predetermined 100 μm, the output of the summing amplifier 15 becomes zero, the input to the servo valve 11 becomes zero, and the piston of the hydraulic cylinder 8 stops.

As described above, the roll gap on the meandering side of the rolled material 9 is tightened by an amount determined by the meandering amount and the gain set in the regulator 21, and the roll gap on the opposite side is opened by the same amount. As a result, the meandering is corrected and the rolled material 9 is returned to the target value given in the setting decision 19. Of course, the above-mentioned control is continuously performed on the meandering amount of the rolled material 9 that is detected from time to time.

In this way, meandering (lateral deviation) of the rolled material 9 is prevented.

Although the present invention has been described above and an example of application to a four-high rolling mill has been shown, the present invention can be applied to all types of rolling mills where meandering is a problem, and the control circuit is not hardware but software using a computer. It goes without saying that the present invention can also be constructed using clothing, and that various other changes can be made without departing from the gist of the present invention. Also, although Fig. 5 only shows the left and right position control system of the hydraulic rolling mill, in reality, in addition to the position control system, the rolling load is measured with a load cell, and the elongation of the mill is calculated and calculated. Although a mill constant control circuit for correction is provided, it is omitted because it is not the gist of the present invention.

[Effects of the Invention] As described above, according to the present invention, in hot rolling equipment such as a hot strip mill or a plate mill, the amount of deviation of the rolled material on the entrance side of the rolling mill can be directly detected, and the Since the left and right roll gap is controlled to change until it reaches zero, rolling can be stabilized by preventing meandering of the rolled material.As a result, the camber of the rolled material is reduced, improving the product yield. It is possible to prevent accidents caused by meandering of the rolled material, improving the operating rate, and it is also possible to roll strips with fewer crowns, thereby improving yields. Since the end position of the rolled material can be continuously detected using the radiant light emitted by the rolled material, highly accurate meandering control is possible.

[Brief explanation of drawings]

Figure 1 is a plan view showing the inclination of the rolled material when there is a difference between the left and right roll gaps, Figure 2 is a vertical sectional view of the roll axis in Figure 1, and Figure 3 is an example of a conventional control system. , FIGS. 4A, B, and C are front views showing the relationship between the meandering of the rolled material and the rolling force, FIG. 5 is an embodiment of the apparatus of the present invention, and FIG. 6 is a detailed view of the detector.
7 and 8 are graphs showing video signals output by the detector of FIG. 6. FIG. 1, 2... Upper and lower work rolls, 7, 8... Hydraulic cylinder, 9... Rolled material, 11, 12... Servo valve, 13, 14... Displacement detector, 15, 16...
Adding amplifier, 17... Plate end position detector, 18...
...Arithmetic unit, 19...Setting device, 20...Comparison arithmetic unit, 21...Meandering control regulator.

Claims (1)

[Claims] 1. A rolling mill that rolls heated metal ingots has a large number of imaging elements on the working side and drive side of the entry side of the rolling mill that form images of light at approximately equal intervals in the width direction of the rolled material, which captures the radiation emitted by the rolled material. A detector capable of detecting the end position of the rolled material based on light is provided, and a computing unit that calculates the meandering amount of the rolled material from the difference in output signals of each detector, and a target position of the rolled material. and a device for comparing and calculating the output signal of the computing device with the target signal of the setting device, and processing the signal obtained by the device as a reduction correction signal for the work side and the drive side. What is claimed is: 1. A meandering control device, comprising: a device for outputting an output, and a roll gap on a work side and a drive side are changed based on the reduction correction signal.