JPH0613127B2 - Meander controller - Google Patents

Description

The present invention relates to an apparatus for controlling meandering of a rolled material.

[Prior Art] In the rolling operation, there is a phenomenon in which the rolled material cannot stay in the center of the roll due to the conditions during rolling and moves toward the end of the roll as the rolling progresses as shown in FIG. It is well known and is called meandering.

The meandering of the rolled material will be briefly described below.
The figure shows a state in which the rolled material a shifts from the center of the work roll b to the right side for some reason. In the case of FIG. 5, the roll gap becomes uneven on the left and right, and the gap on the right side Is wider than the left side. By the way, although the peripheral speed of the work roll b is uniform on the left and right, the gap on the right side is wider, so the volumetric flow rate of the rolled material per unit time is larger on the right side. Further, if the thickness of the rolled material on the entry side is symmetrical, the material is drawn in earlier on the side of the larger volumetric flow rate. As a result,
As shown in FIG. 6, the rolled material a moves toward the right side on the entrance side (Δx), and a camber (Δy) occurs on the exit side. Therefore, the difference between the left and right roll gaps is further increased, and the rolled material a approaches the right end more rapidly, and a phenomenon of meandering occurs. Along with that, the camber also increases.

To prevent such meandering and accompanying camber,
It is effective to carry out rolling under the condition that the rolled material has a convex crown. However, in recent years, the demands for quality improvement and yield improvement of rolled materials have become strict, and it is required to reduce the convex crown as much as possible and perform rolling so as to have a uniform thickness distribution in the longitudinal direction and the width direction. Under these conditions, meandering of the rolled material is likely to occur and stable operation is difficult.

In recent years, as one of the means for preventing the meandering, when the rolled material meanders, the force applied to the left and right load cells c and d (see FIG. 5) changes. Means have been proposed to try to prevent this by moving the reduction device so as to narrow the roll gap on the increased side.

However, with the above-mentioned means, there is a problem that the load output change due to meandering and the load output change due to the operation of the rolling down device are overlapped, and the control system is unstable, which easily causes divergent vibration, and the accuracy is insufficient. In addition, it is difficult to associate the load difference between the left and right with the actual meandering amount of the rolled material, and there is a drawback that it cannot be put to practical use at all.

Therefore, in order to solve the above problems, the present inventors have
For example, we have proposed a meandering control means as shown in Japanese Patent Application No. 58-65109. In the meandering control means, an end position detector for detecting the width end position of the rolled material is provided on the working side and the driving side of the rolling mill entrance side, and the difference between the output signals of the respective end position detectors is calculated. A device for calculating the amount of meandering and a setter for giving a rolled material target position, and a device for comparing and calculating the output signal of the calculator and the target signal of the setter, and a signal obtained by the device The working side and the driving side are provided with a device for outputting as a rolling reduction signal, and the rolling gaps on the working side and the driving side are changed by the rolling reduction signal.

In the meandering control device, the same meandering correction amount is controlled so that the meandering correction effect is the same regardless of the rolling conditions such as plate width, plate material, plate temperature, reduction rate and rolling speed. It is desirable to do.

[Problems to be Solved by the Invention] However, in the above-described meandering control device, the meandering correction effect is different if the strip width is different even if the material of the rolled material is the same and the same correction amount is different, and the strip width is the same and equal. Even if the reduction amount is different, the meandering correction effect is different if the plate material is different.

The present invention has been made in view of the above circumstances and has an object to make the meandering control effect the same for the same rolling reduction amount regardless of the rolling conditions such as the strip width and the strip material.

[Means for Solving the Problems] The present invention provides an end position detector for detecting the end position of a rolled material width provided on the working side and the driving side of the rolling mill entrance side, and the end position detector. A device for calculating the meandering amount by calculating the difference between the output signals, a device for comparing and calculating the output signal of the device and the target position signal of the rolled material, and a reduction correction on the working side and the driving side from the signal obtained by the device In a meandering control device equipped with a device for obtaining and outputting a signal, the working side and the drive side roll gaps are changed by a reduction correction signal, a control gain set in the device for obtaining and outputting the reduction correction signal is a rolling material. It is equipped with a device for changing the strip width, strip material, and other rolling conditions.

[Operation] During rolling, the meandering amount is obtained from the end position of the rolled material width detected by the end position detector, and is proportional to the control gain corresponding to the rolling condition from the difference between the meandering amount and the target position of the rolled material. Then, the left and right reduction correction signals are obtained, and the left and right roll gaps are adjusted by the reduction correction signal to perform meandering control,
When the rolling conditions such as the strip width and the strip material of the strip are changed, the magnitude of the control gain set in the device for obtaining and outputting the reduction correction signal is changed.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention, in which the upper and lower work rolls 1 and 2, the upper and lower backup rolls 3 and 4, and the lower end supporting both shaft ends of the above backup rolls 3 and 4. Hydraulic roll-down rolling mill equipped with backup roll chocks 5 and 6 and hydraulic cylinders 7.8 that apply rolling force to each of the lower backup roll chocks 5 and 6 to roll rolled material 9.
10, the amount of pressure oil that flows in and out of the left and right hydraulic cylinders 7 and 8 is controlled by the servo valves 11 and 12, and the displacement detector 13, which detects the movement of the pistons of the hydraulic cylinders 7 and 8 14 is attached to the hydraulic cylinders 7 and 8, and adding amplifiers 15 and 16 for comparing the signals from the displacement detectors 13 and 14 with the setting signals are provided. The left and right roll gaps are set by controlling the amount of pressure oil that flows in and out of the hydraulic cylinders 7 and 8 by the servo valves 11 and 12, and the roll gap fluctuation is determined by the movement of the pistons of the hydraulic cylinders 7 and 8. Indirectly measured by displacement detectors 13 and 14 that detect
If there is a difference compared with the set signal by the summing amplifiers 15 and 16, the servo valves 11 and 12 are controlled by the difference to correct the difference. Further, the end position detectors 17a and 17b for detecting the width end positions of the rolling material 9 based on the light emitted from the rolled material 9 are installed on the right and left sides of the rolling mill 10 entrance side, and the respective end position detectors 17a and 17b are installed.
The difference between the signals from b, that is, the meandering amount of rolled material 9
18, the meandering amount and the target signal from the setter 19 are compared and calculated by the comparison calculator 20, and the obtained meandering amount deviation signal 22 is processed by the meandering control adjuster 21 to obtain the right and left reduction correction signals 23. , 24 is added to the summing amplifiers 15 and 16, and the meandering control controller 21 sends a command from the process computer 25 according to rolling conditions such as strip width, strip material, strip temperature, reduction rate, and rolling speed. Control gain K of the meandering control controller 21
_{Allow P} to be changed. The output of the adjuster 21 is, for example, when the rolled material 9 approaches the working side, the roll gap on the working side is tightened to open the roll gap on the driving side, and the rolled material 9 approaches the driving side. In this case, the direction is determined so that the roll gap is controlled, and it is added to the summing amplifiers 15 and 16. In addition,
Reference numeral 26 in the figure is a reduction control device.

A calculator based on the signals detected by the end position detectors 17a and 17b
In 18, the meandering amount of rolled material 9 is calculated, and the meandering amount and setter 19
The target signal from is compared and calculated by the comparison calculator 20, and the obtained meandering amount deviation signal 22 is set in advance by the process computer 25 by the meandering control controller 21 according to the rolling conditions such as strip width and strip material. It is multiplied by the control gain k _P and given to the summing amplifiers 15 and 16 as left and right reduction correction signals 23 and 24. For this reason, the summing amplifiers 15 and 16 compare the displacement signals of the actual pistons of the hydraulic cylinders 7 and 8 with the pressure reduction correction signals 23 and 24, and the servo signals 11 and 12 cause the hydraulic cylinders 7 and 8 to respond to the difference signals.
By controlling the inflow and outflow of pressure oil to 8, the left and right roll gaps are changed, the further progress of meandering is stopped, and the rolling material 9 is the target value given by the setter 19. Returned to.

When the rolling conditions such as the strip width and the strip material of the rolled material 9 are changed, the process computer 25 changes the control gain K _P of the meandering control adjuster 21 according to the rolling conditions.

For example, according to the calculation by the inventor, the relationship between the strip width W of the rolled material 9 and the control gain K _P is shown in FIG. 3, and in order to make the meandering correction effect the same, the wider the strip width W is, the more the control gain K _P becomes. The larger the plate width W and the narrower the plate width W, the smaller the control gain K _P needs to be.

Next, the plate material of the rolled material 9, that is, the relationship between the control load K _P and the ratio δp / δh of the rolling load variation δp and the sheet thickness variation δh is shown in FIG. 4, and the smaller δp / δh (that is, , The softer the rolled material), the smaller the control gain k _P ,
The larger δp / δh (that is, the harder the rolled material)
It is necessary to increase the control gain K _P.

As described above, since the control gain K _P is changed according to the rolling condition, the meandering correction effect can be always the same, and stable meandering control can be performed.

Further, since the meandering amount can be directly obtained from the rolled material end position detected by the end position detector, it is not necessary to associate the left and right load difference with the meandering amount as in the conventional case, and the stable region of control can be obtained. Becomes wider in each stage, and there is no need to make fine adjustments to the control gain.

In the embodiment of the present invention, the case where the target position of the rolled material is given by the setter 19 has been described, but the initial biting position of the rolled material 9 into the rolling mill is stored and given as a control target. It is also possible to set the width of the rolled material 9 to any position in the width direction of the rolled material and to change the width end position by the light emitted from the rolled material itself when the temperature of the rolled material is high. If the temperature of the rolled material detected is low, it is possible to provide a light source above or below the rolled material and detect the width end position based on the light from the light source.
Not only the four-high rolling mill but also applicable to all types of rolling mills where meandering is a problem, the control circuit can be configured by software using a computer instead of hardware, and the end position detector can be installed on the entrance side of the rolling mill. It is needless to say that the control device of the present invention can be provided on both the output side and the signal of both, and that various changes can be made without departing from the scope of the present invention. .

EFFECTS OF THE INVENTION According to the meandering control device of the present invention, since the control gain can be changed depending on the rolling conditions such as the strip width and the strip material, it is possible to always perform the stable serpentine control, and the stable control region can be obtained. Since it becomes wider, fine adjustment of the control gain becomes unnecessary, and therefore various excellent effects such as improvement of production efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the meandering control device of the present invention, FIG. 2 is a detailed explanatory view of the meandering control device of FIG. 1, and FIG. 3 is a graph showing a relationship between rolled material strip width and gain. FIG. 4 is a graph showing the relationship between the rolling load fluctuation amount and the plate thickness fluctuation amount and the control gain, FIG. 5 is an explanatory diagram when the rolled material meanders to one end side of the roll, and FIG. 6 is FIG. FIG. In the figure, 1 and 2 are work rolls, 7 and 8 are hydraulic cylinders, and 11 and 12
Is a servo valve, 13 and 14 are displacement detectors, 15 and 16 are addition amplifiers, 17a and 17b are end position detectors, 18 is a calculator, 19 is a setter, 20 is a comparison calculator, and 21 is a meandering control adjustment. Reference numeral 25 denotes a process computer.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Shinichiro Taniguchi, 1850 Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Steel Works (72) Hiroaki Miura, 1850, Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Works (56) References JP-A-61-147913 (JP, A)

Claims (1)

[Claims] 1. An end position detector for detecting an end position of a rolled material width, which is provided on a working side and a driving side of at least one of an inlet side and an outlet side of a rolling mill, and an output of the end position detector. A device for calculating a meandering amount by calculating a signal difference, a device for comparing and calculating an output signal of the device and a target position signal of a rolled material, and a rolling-down correction signal on a working side and a driving side from a signal obtained by the device. In the meandering control device, which is equipped with a device for obtaining and outputting, the working side by the reduction correction signal and the roll gap on the driving side, in the meandering control device, the control gain set in the device for obtaining and outputting the reduction correction signal A meandering control device provided with a device that changes according to rolling conditions such as strip width and strip material.