CN1830588A - Control method and control device for rolling device - Google Patents

Abstract

The control method for rolling unit has several applicable control systems with altered control target values for some control target on the same control target. The control systems have their control target values altered within the allowed control precisions so as to interfere for realize different control targets. During the rolling shape control of the rolling mill, the control target values of the bending machine and the cooling agent are altered to makes it possible to obtain required rolled plate shape. While maintaining the control precision within certain range, different control purposes may be reached.

Description

Control method and control device for rolling device

technical field

[0001]

The invention relates to a control method of a rolling device and a control device thereof.

Background technique

[0002]

In cold rolling mills for producing metal sheets, shape control for controlling the shape of a material to be rolled (waviness of the sheet) has been performed conventionally. Shape control makes the actual signal from the shape detector installed on the output side of the rolling mill consistent with the target shape, using the bender (bender) installed on the rolling mill (applying pressure at both ends of the work roll to generate a deflection control shape), Coolant nozzles (or also referred to as positional cooling, hereinafter the same) are performed (using the thermal expansion caused by the rolling of the work roll to control the shape). Such a technique is disclosed in Japanese Unexamined Patent Publication No. 2004-66310, for example.

[0004]

On the one hand, the shape of the rolled material in the rolling mill is determined by the surface shape of the work roll, and the part of the work roll where the rolled material is present has a large thermal expansion due to the heat generated by the processing of the rolled material; on the other hand, there is no Since the part of the work roll of the rolled material does not generate heat, the thermal expansion is continuously reduced. Therefore, the radius of the work rolls will decrease sharply at the end of the plate, the gap between the work rolls will increase sharply at the end of the plate, the amount of reduction caused by rolling will become smaller, and the elongation of the end of the plate will become smaller. Minor edge tension.

[0005]

The edge tension phenomenon is that the tension at the end of the board is in a high state. In the above process, if there is a crack at the end of the board, the board will be cut from the crack as the starting point, and the so-called edge fracture phenomenon will easily occur.

[0006]

In order to prevent such edge breakage, it is necessary to reduce the tension applied to the end of the board in shape control (control the end of the board in the direction of elongation), but if the target shape of the end of the board is to be changed, the center of the rolled material The shape of a part is affected, causing a decrease in the quality of the product as a whole.

Contents of the invention

[0007]

An object of the present invention is to prevent edge breakage at ends in the width direction while maintaining the overall shape quality in the width direction.

[0008]

In order to achieve at least one of the above-mentioned objects, in the present invention, the control amount of the bending machine and the control amount of the coolant are controlled so as to become a target shape. The measured value of the end portion in the predetermined width direction is set so that the target shape under bending machine control and the target shape under coolant control are different.

[0009]

Or, control the first control amount and the second control amount so as to become the target processing, and make the target value under the first control and the target value under the second control according to the measurement values of the processing objects that are different from the target processing object. The target value of is configured in a different way to set it.

[0010]

According to the present invention, the shape quality as a whole in the width direction can be maintained, and at the same time, edge breakage at the ends in the width direction can be prevented. In addition, not only the rolling device but also the control of a predetermined part and the processing device that affects other parts can reduce the influence.

Description of drawings

[0044]

Figure 1 is a control configuration diagram.

Fig. 2 is an overall configuration diagram.

Fig. 3 is an applicable diagram in edge tension correction.

FIG. 4 is an explanatory diagram of area division for shape control.

Fig. 5 is an explanatory diagram of an edge tension phenomenon.

Fig. 6 is a detailed diagram of an edge tension judging device.

Fig. 7 is an operation diagram of the object shape changing device.

Fig. 8 is an explanatory diagram of thickness and tension control in a rolling mill.

Fig. 9 is an operation diagram in plate thickness and tension control.

Symbol Description

[0045]

21-Rolled material, 22-Work roll, 23-Intermediate roll, 24-Coolant nozzle, 302-Edge tension determination device, 303-Target shape change device, 304-Bending machine shape control, 305-Coolant shape control.

Detailed ways

[0011]

Hereinafter, embodiments of the present invention will be described using drawings. First, a general example of a control system applied to the present invention will be described using FIG. 1 .

[0012]

Control object 11 includes control object A (for example, the shape of the center part described later), and control object B1 (corresponding to the shape of the WS edge part described later)...Control object Bn (corresponding to the shape of the DS edge part described later) . These can also be distribution values such as the distribution in the sheet width direction in the rolled material, for example. For each value, a measurement value 12 of the control object A, a measurement value 13 of the control object B1 , and a measurement value 14 of the control object Bn are measured by a measuring device (not shown). The target setting means 15 sets the target value 17 of the controlled object A. Control system-1 (16) ... control system-n (17), in order to make the measured value 12 of each control object A and the target value 17 of the control object A (if outputting the target value change value 22 of the control object A1 described later, There is no deviation between the target value change value 23 of the control object An, and the value obtained by subtracting the values) is controlled for the control operation object 18 (e.g., corresponding to a bending machine described later) and the control operation object 19 (e.g., equivalent to a bending machine described later). coolant) for control.

[0013]

The controlled object state judging means 20 judges whether the measured value 13 of the controlled object B1, ... the measured value 14 of the controlled object Bn is an allowable value. If it is not a permissible value, the control target value changing means 21 outputs a non-permissible value (and its control object). The control target value changing device 21 outputs the control target value changing value (22 ~23) any one (or part of). In addition, the control target value changing means 21 outputs a control target value change value in order to keep the other control target values unchanged or to reduce the influence on the control object A caused by the change.

[0014]

In this way, on the control object to which multiple control systems are applied, the value of the state variable of the applied control system can be maintained, and other control variables can be controlled at the same time. Specifically, as shown in FIG. 1 , a control target state judging device 20 for judging the state of the control target becoming a new control target and a control target value changing device 21 for changing the control target value of each control system based on the judgment result are provided. For the control object, in the control system where multiple control systems are applied, in order to achieve a certain control purpose, if a new control system is applied, it may interfere with the existing control system. In that case, through By changing the control target value of an existing control system and causing interference between control systems, it is possible to achieve a new control target while maintaining the control accuracy within the allowable value.

[0015]

Next, an example in which the control concept described above is specifically applied to the control of a rolling apparatus will be described. In Fig. 3, #1 station 801 and #2 station 802 are respectively provided with the upper and lower pair of work rolls 22 (22a, 22b) which are in direct contact with the rolled material 14 and rolled, and supported in the vertical direction A pair of upper and lower intermediate rolls 23 (23a, 23b) of the work roll 22. Although not disclosed, the middle roll 23 is supported vertically by upper and lower pairs of reinforcing rolls. Although the work roll bending device (the acting direction of the bending force is shown in the arrow direction F) is not shown in the figure, the work roll bending device acts on the work roll 22 with a bending force. In addition, a roll shifting device that moves the intermediate roll 23 in the axial direction is provided.

[0016]

For the work roll 22, a coolant nozzle 24 that sprays coolant is provided. The coolant nozzle 24 (or also called positioning cooling) is provided with multiple nozzles within the range of the plate width, and each nozzle is equipped with a flow-adjustable valve (not shown), which can adjust the injection flow. Furthermore, each flow rate adjustable valve can individually control the flow rate of injection. In the web direction of the material to be rolled 21 , it is possible to spray with a flow distribution.

[0017]

On the delivery side of the work rolls 22, a shape detector 25 for measuring the shape of the material to be rolled 21 is provided.

[0018]

In FIG. 3 , the shape detector 25 outputs, for example, every 50 mm in the web direction. The output is indicated by reference numeral 41 in FIG. 4 . The shape measuring mechanism 301 decomposes the output of the shaper 25 and outputs it as a WS edge (operating side edge) shape 42 , a center portion shape 43 , and a DS edge (driving side edge) shape 44 as shown in FIG. 4 .

[0019]

The center portion shape 43 is input to the bending machine shape control 304 and the coolant shape control 305 together with the target shape set by the target shape setting device 306 . Also, the bender shape control 304 controls the bending force F of the work roll 22 , and the coolant shape control 305 controls the injection amount of the coolant nozzle 24 .

[0020]

In general, when the product is shipped, the edge portion is often cut off. In terms of product quality, even for the product guarantee of the end user, the center portion shape 43 is often the object, so the center portion 43 is very important. The shape of the central part is important, and the bending machine shape control 304 and the coolant shape control 305 for controlling the output plate shape are suitable, and the control object of these controls is the central part shape 43 shown in FIG. 4 . The center shape 43 is a portion excluding the WS edge shape 42 and the DS edge shape 44 at the outermost end in the shape detected by the shape detector. In this embodiment, due to the shape of the outermost edge, misdetection caused by meandering of the plate is very likely to occur, so it is excluded from the control range of the target setting of the target shape setting device 306, and the center shape 43 Control as an object of shape control.

[0021]

In this way, the bender shape control 304 and the coolant shape control 305 are used to control the shape of the rolled material (the undulation of the plate) as the control of the cold rolling mill for producing thin plates. That is, the shape is controlled so that the actual signal from the shape detector installed on the output side of the rolling mill matches the target shape, using the bending machine installed in the rolling mill (pressing is applied to the work rolls to generate deflection and shape control) , Coolant nozzle (positional cooling) (use the thermal expansion caused by the rolling of the work roll to control the shape.).

[0022]

For shape control, two types of bending machine shape control 304 and coolant shape control 305 are used. In the bending machine shape control 304, shape correction is performed in the form of a quadratic to quaternary function along the entire sheet width direction. On the other hand, , in the coolant shape control 306, the shape is controlled by selecting whether to spray or not to spray coolant in accordance with the detection area width (about 50mm) of the shape detector 25.

[0023]

Details of the edge tension determination device 302 are shown in FIG. 5 . In the edge tension determination device 302, the WS edge shape 42 and the DS edge shape 44, which are the shapes of both edges, are input. is the positive direction, so the tension direction=the tension direction is the negative direction) is judged as edge tension. As the determination of such edge tension, the WS side and the DS side are respectively determined.

[0024]

Referring to the edge tension, the shape of the material to be rolled in the rolling mill is determined by the surface shape of the work roll 22 and the thickness distribution of the material to be rolled 21 in the width direction as shown in FIG. 5 . The work roll 22 thermally expands due to heat generated by rolling, and the portion of the work roll 22 where the material to be rolled 21 does not exist does not generate heat because there is no heat generated by rolling. Between the heat-generating part and the non-heat-generating part, heat is diffused from the heat-generating part to the non-heat-generating part, so thermal expansion is continuously reduced. When the heat generated by rolling is large, the reduction rate of such thermal expansion becomes large, and the radius of the work roll 22 decreases sharply at the edge of the plate. Therefore, at the edge of the sheet, an edge tension phenomenon in which the amount of reduction by rolling becomes small and the elongation of the edge of the sheet becomes small occurs.

[0025]

In the operation of the above steps, if there is a crack at the end of the plate of the material to be rolled 21, when tension is applied therein during the rolling of the plate, the plate will be cut from the crack as a starting point. This phenomenon is edge fracture. To prevent this, it is necessary to prevent edge tension at the end of the plate, where excessive tension is applied.

[0026]

Edge tension control by changing the target shape by the target shape changing device 303 will be described with reference to FIG. 7 . In the edge tension control, since the edge tension phenomenon is a state in which the tension at the edge of the plate is high, from the viewpoint of preventing edge breakage and improving work efficiency, in order to prevent edge breakage, reduce the force applied to the edge of the plate. The tension (controlling the end of the plate in the direction of elongation).

[0027]

In the target shape changing device, as shown in FIG. 7 , the target shape of the coolant shape control is changed from the target shape of the bending machine shape control. The target shape of the bender shape control 304 is the same as the center part target shape. By changing the target shape of the coolant shape control 305, the coolant shape control 305 sprays the coolant whenever it recognizes that the shape of the end portion of the inner panel near the outermost edge is elongated. Thereby, it becomes the operation|movement of the following 1).

[0028]

1) Reduce the rate of change at the plate end of the thermal expansion of the roll. Therefore, the temperature change of the plate end is performed smoothly by the sprayed coolant concentrated at the plate end.

[0029]

In addition, for the bending machine shape control 304, since the coolant shape control 305 controls the shape of the edge portion in the tension direction (the direction in which the elongation is small), it is also judged that it is necessary to stretch, and in the direction of closing the roll gap The operation of the bending machine becomes the operation of 2) below.

[0030]

2) The bending machine is controlled so that the edge of the plate is further pressed down (the gap between the rolls becomes smaller).

[0031]

In this way, if the coolant can be effectively used, the edge tension phenomenon can be effectively suppressed, but if the overall shape of the sheet width direction is taken out from the target shape, the quality of the product cannot be guaranteed. Therefore, the target shape changing device 303 should change the target shape so as to suppress edge tension while maintaining the overall shape in the width direction at a certain level (a level that is not problematic as a product). That is, in order to improve product quality, different target shapes are actively given to the coolant shape control 305 and the bending machine shape control 304 that use the same target shape, so that interference occurs between the two controls.

[0032]

The target shape changing device 303 sets the target shape in order to maintain the actual shape of a shape that facilitates the rolling operation in the center portion shape control for the purpose of not deteriorating the shape quality of the center portion. Therefore, it is considered that the closer the actual shape is to the target shape, the better the control accuracy is. Since there is a certain allowable value of control accuracy, the coolant shape control 305 and the bending machine shape control 304 can respectively have the target shape, so that the above-mentioned The edge tension caused by 1) and 2) can be suppressed, and the shape of the central part can be changed so that it is within the allowable value.

[0033]

In this way, by changing the target shape in the coolant shape control 305 and the bender shape control 304, edge tension suppression control can be realized.

[0034]

Here, when the bender of the work roll 22 operates separately (an asymmetrical bender can be used) WS (operation side bender) and DS (drive side bender), the above-mentioned object is implemented for the side determined by the edge tension determination device 302 Shape changes. When the work roll benders WS and DS cannot be operated separately, on the edge tension judging device 302, the above-mentioned target shape can be implemented for the WS side and the DS side only when both sides have judged the edge tension of WS and DS at the same time. change.

[0035]

In this embodiment, the target shape on the coolant shape control 305 side is changed, but the target shape on the bending machine shape control 304 side may be changed. In addition, it is also possible to change the object shape of both sides. Generally, the target shape with a low variation control effect has a small amount of deviation from the target shape of the central portion shape 43 and good shape accuracy. In normal rolling, the shape of the work roll 22 is greatly influenced by the coolant in the bender, so in the embodiment, the target shape of the coolant shape control 305 is changed.

[0036]

As a second embodiment of the present invention, similarly, thickness control 803 and tension control 804 in a rolling mill are considered. Note that the description of the first embodiment is the same as that of the first embodiment using the same symbols. In the two continuous rolling mills shown in FIG. 8 , an inter-stand tension control 804 for controlling the inter-stand tension and a plate thickness control 803 for controlling the exit side plate thickness of #2 ( 802 ) are applied. The operating end of the plate thickness control 803 is #1 (801) speed. For the tension control 804, the #1 (801) speed is operated at a low speed. If the speed rises, the #2 (802) is operated to press down. Since rolling is unstable at low speeds, it is used at speeds with great operational effects to give priority to operational stability. Here, in order to start from a certain speed, the tension control 804 changes the operating end to press the #2 unit (802), and the speed command output to the #1 unit (801) remains before that. If the speed command remains, the rolling may become unstable because the setting values of the speed balancers of #1 station 801 and #2 station 802 are different.

[0037]

Therefore, when the speed command of the tension control 804 of the #1 machine 801 remains, for the purpose of eliminating it, the thickness deviation of the thickness control 803 and the tension of the tension control 804 are corrected, and pass within the allowable range of the thickness accuracy The plate thickness is deliberately messed up inside, and the speed command part of the tension control 804 is eliminated to perform stable rolling.

[0038]

Fig. 9 shows an outline of the operation. The rolling mill realizes the operation from speed 0 to low speed and from low speed to high speed. When the speed is low, the tension control 804 takes the speed of #1 unit (801) as the operating end. When accelerating from low speed, the tension control takes #2 (802) as the operating end. When it becomes high speed, the speed correction amount becomes almost 0 due to the change of the rolling state. This is because when the speed is set at high speed, it is set so that the plate thickness and tension become the set values. Conversely, if a large amount of speed correction remains at high speed, the rolling state will be different from the prediction, resulting in unstable rolling state, misalignment, etc. In order to prevent it, it is necessary to control the speed command to #1 unit near 0.

[0039]

In order to achieve this, even at high speeds, use the speed correction amount judging device 805 to identify the remaining speed command of machine #1, and in the control command changing device 806, obtain the correction amount for the plate thickness and tension, and use it as a value for each control device. (The correction amount of the speed control device 807 and the pressing control device 808). In the case of the example in Fig. 9, since the speed correction amount remains on the positive side, in order to make it 0 in the thickness control, it is necessary to recognize the thickness deviation as the negative side, and output the thickness so that the target value of the thickness control is increased. correction amount. On the other hand, the tension control 804 outputs a tension correction amount that reduces the tension control target value so that the tension deviation is on the plus side and the plate thickness is increased to feed. Also, the correction amount is set so that the plate thickness and tension fall within the allowable range of the control accuracy.

[0040]

By changing the target value of the plate thickness control and tension control, the interference of the two control systems will be generated, and the #1 (801) speed command will be reduced to 0. If the #1 (801) speed command becomes smaller before reaching the allowable level, the target values of the plate thickness control 803 and the tension control 804 are returned to the original values. As a result, the thickness accuracy and tension accuracy can be kept within the allowable error, and the stability of rolling can be ensured.

[0041]

When a plurality of control systems are applied to one control object, the present invention can be applied to a control system that may achieve a purpose different from the original control purpose by using the present invention.

[0042]

In this way, while maintaining the shape as a whole in the width direction of the board, the edge tension phenomenon can be suppressed, and the shape accuracy and work efficiency can be improved.

[0043]

Generally, by using the present invention, it is possible to maintain the control accuracy of each control system within the allowable range, and to add control to new control variables.

Claims (10)

1. A control method for a rolling device, for the purpose of changing the material to be rolled into a target shape, and controlling the control amount of the bending machine and the control amount of the coolant, characterized in that, The above-mentioned target shape includes the inner side near the predetermined end in the width direction of the material to be rolled, and the target shape in the control of the bending machine and the above-mentioned The target shape in coolant control is set in different ways. 2. The method for controlling a rolling device according to claim 1, wherein: The target shape in the coolant control is set in such a manner that the tensor is smaller than the tension at the predetermined edge in the width direction when the target shape in the coolant control is the same as the target shape in the bending machine control. . 3. The method of controlling a rolling device according to claim 1, wherein: The coolant control is set in such a manner that the coolant is sprayed to be larger than the cooling amount of the edge portion in the width direction of the material to be rolled when the target shape in the coolant control is the same as the target shape in the bending machine control. The target shape in . 4. The method for controlling a rolling device according to claim 3, wherein: The target shape in the bending machine control and the target shape in the coolant control are set to be the same, and the target shape in the subsequent coolant control is changed. 5. The method of controlling a rolling device according to claim 4, wherein: The modification of the above-mentioned target shape is to reduce the tensor of the end portion in the width direction of the above-mentioned material to be rolled; The above-mentioned bending machine is controlled in such a manner that the variation in plate thickness and shape due to the above-mentioned coolant control is corrected. 6. A control method for a rolling device, which controls the shape of the rolled material by controlling the control volume of the bending machine and the control volume of the coolant, characterized in that, In order to control the shape change of the end portion in the width direction of the material to be rolled, the bending machine control and the coolant control are respectively changed, or the shape control target value of one of them is changed. 7. A control method for a processing device using two or more control systems for a common control object, characterized in that, A control target value for one or more of the two or more control systems is changed so as to control a control variable different from a control variable that is a control target of the respective control systems. 8. A control device for a rolling device, which controls a bending machine control amount and a coolant control amount so that a material to be rolled becomes a target shape, characterized in that, The above-mentioned target shape includes the inner side close to the predetermined end in the width direction of the material to be rolled, A setting mechanism is provided for setting the target shape in the bending machine control based on the measured value including the measured value of the predetermined edge in the width direction so as to be different from the target shape in the coolant control. . 9. A control device for a rolling machine, in the rolling mill control device that controls the shape of a material to be rolled by controlling the control amount of the bending machine and the control amount of the coolant, characterized in that, The bending machine control and the coolant control, or one of the shape control target values is changed separately so as to control the local shape change of the end portion in the width direction of the material to be rolled. 10. A control device for a processing device to which two or more control systems are applied to a common control object, wherein: A control target value for one or more of the two or more control systems is changed so as to control a control variable different from a control variable that is a control target of each of the above-mentioned control systems.

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