JP2515028B2 - Rolling mill shape control method and apparatus for implementing this method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rolling mill shape control method for rolling while controlling the shape of a rolled sheet material, and an apparatus for carrying out this method.

[Conventional technology]

In general, a rolling mill is arranged side by side in the length direction of a rolling roll, roll cooling means such as a plurality of cooling medium injection nozzles for injecting a roll cooling medium to control the shape of the surface of the rolling roll, and the width of the rolled plate material. A shape detector for detecting the shape in the direction is provided, and the shape of the rolled plate material is automatically controlled by operating the roll cooling means according to the output signal from the shape detector. When the roll cooling means is a plurality of cooling medium injection nozzles, these cooling medium injection nozzles are independently controlled by the output from the shape detector to adjust the thermal crown of the rolling roll to adjust the shape of the rolled plate material. Proper control is in place.

According to one prior art control method, a plate material portion determined to have a locally high tensile tension in the length direction of the rolling roll (width direction of the rolled plate material) based on an output signal from the shape detector is used. Stops the injection of roll cooling medium,
On the other hand, the rolled sheet material is controlled by injecting a roll cooling medium to the sheet material portion where it is determined that the rolled sheet material is extended and the tension is low.
It is common to apply F control.

In another conventional control method, instead of this ON-OFF control, the flow rate control valve is used to control the flow rate by continuously adjusting the flow rate of the cooling medium injection nozzle.

[Problems to be Solved by the Invention]

However, all of the above-mentioned conventional techniques control the roll cooling medium by paying attention only to the output signal from the shape detector, so that the control method in the length direction of the rolling roll is the same, which causes the thermal crown. It is not possible to sufficiently control local elongation such as quotas and buckles, and overshoot occurs because the control logic to compensate the changing direction, that is, the rate of change of shape is not incorporated. In some cases, the shape of the rolled plate could not be controlled accurately.

One object of the present invention is to avoid the above-mentioned drawbacks, and to efficiently control the shape of a rolled sheet material by quickly responding to various changing rolling conditions without performing complicated calculations such as simulation using a mathematical model. It is to provide a shape control method for a rolling mill.

Another object of the invention is to provide a device capable of achieving the above method.

[Means for solving the problem]

In order to solve the above problems, the present invention includes an actuator that controls the shape or state of the surface of a rolling roll during rolling, and a shape detector that detects the shape in the width direction of a rolled plate material. In a rolling mill that controls the shape of the rolled sheet material by operating the actuator according to the output signal from the, the output signal of the shape detector is decomposed into multiple evaluation indices, and this is obtained as a fuzzy amount, and fuzzy inference is performed. The shape of the rolled sheet material is controlled by determining the control amount of the actuator by this evaluation index. This evaluation index includes the difference in elongation difference rate, the change rate of the elongation difference rate, and the local elongation evaluation index. The present invention provides a shape control method for a rolling mill, wherein at least two evaluation indexes are used for fuzzy reasoning.

In order to solve the above problems, the present invention includes an actuator that controls the shape or state of the surface of a rolling roll during rolling, and a shape detector that detects the shape in the width direction of a rolled plate material. In a rolling mill that controls the shape of the rolled sheet material by operating the actuator according to the output signal from the, the output signal of the shape detector is decomposed into multiple evaluation indices, and this is obtained as a fuzzy amount, and fuzzy inference is performed. The fuzzy inference means for determining the control amount of the actuator is further provided according to
A shape control device for a rolling mill including a difference in elongation difference rate, a rate of change in the elongation difference rate, and a local elongation evaluation index, and at least two evaluation indexes of these three evaluation indexes are used for fuzzy inference. Is provided.

[Action]

In this way, the measured data of the shape based on the output signal from the shape detector is obtained as a fuzzy amount, and an actuator for controlling the shape or state of the rolling roll such as roll cooling means is operated by fuzzy reasoning. It is possible to control the shape of the rolling plate with high accuracy by following changes in conditions.

Further, the measurement data of the shape is decomposed into a difference in elongation difference rate, a rate of change in the elongation difference rate, and a local elongation evaluation index, and at least two evaluation indexes of these three evaluation indexes are used for fuzzy inference. If the total result of all evaluation indexes is zero, it is judged that the rolled material is in accordance with the target shape, and the more the total result deviates from zero, the more it deviates from the target shape. The shape control is performed more accurately than in the case where fuzzy control is performed by obtaining the shape parameter from the widthwise distribution. In particular, when high-speed rolling is performed at a high reduction rate, the heat load of the rolling rolls becomes large and local strain is likely to occur in the rolled material. However, the local elongation evaluation index is selected as one of the evaluation indexes and fuzzy When controlled, the growth of local elongation can be controlled and the overall shape of the rolled material can be significantly improved.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 systematically shows an apparatus for carrying out a shape control method for a rolling mill according to the present invention. A rolling mill 10 includes upper and lower work rolls (rolling rolls) 14 for rolling a plate material 12 to be rolled, and an intermediate roll. 16 and backup roll 18
Is taken up by the winder 22 from between the rewinder 20 and the work roll 14.

The rolling mill 10 is further arranged in the lengthwise direction of the work roll 14 (barrel axis direction) and is provided with a plurality of cooling devices for injecting a roll cooling medium onto the work roll 14 in order to control the shape or state of the surface of the work roll 14. Medium injection nozzle 24
An external roll cooling means as an actuator including (see FIG. 2) and a shape detector 26 for detecting the shape of the plate material 12 in the width direction are provided. Each cooling medium injection nozzle 24,
As shown in FIG. 2, the roll cooling medium is supplied from the roll cooling medium tank 28 through the supply pump 30 and the main pipe 32 and the respective valve devices 34. Further, a control command is sent to the valve device 34 from the valve command device 36 which receives the cooling medium output signal calculated by the method of the present invention.

The shape detector 26 supplies an output signal corresponding to the detected shape to the expansion difference rate calculation circuit 38, and this expansion difference rate calculation circuit
Reference numeral 38 designates an output signal (shape signal) of the shape detector 26 as a difference in elongation ε
Convert to (i). The expansion difference rate (i) is an index representing the position in the length direction of the work roll corresponding to each cooling medium injection nozzle 24.

The cooling medium output calculation circuit 40 decomposes the deviation signal between the output signal of the shape detector 26 and the target shape setting value into a plurality of evaluation indexes, obtains this as a fuzzy amount, and injects a plurality of cooling media by fuzzy inference. The injection amount of each of the nozzles 24 is determined and the cooling medium output signal α (i) is sent to the valve command device 36. In the illustrated embodiment, the cooling medium output calculation circuit 40 is supplied with the expansion difference rate ε (i) which is the output of the expansion difference rate calculation circuit 38, and outputs the cooling medium output α (i) as follows. Ask for.

Fig. 3A shows the shape of the rolled plate as the target shape, and the solid line in the figure shows the target shape (target elongation difference ratio) ∈ r when the center of the rolled plate is zero and is expressed as a quadratic function. The chain line shows an example of the shape (actual elongation difference ratio) ε of the rolled plate when the center of the rolled plate is zero. Further, FIG. 3B shows the target difference in elongation ratio εr and the actual difference in elongation ratio ε in discrete values for each division width of the shape detector.
(I), the actual elongation difference rate is represented by ε (i). For the target rate of difference in elongation εr (i) and the rate of actual difference in elongation ε (i), the following three evaluation values are obtained.

(1) Control deviation A (i) This is the target rate of difference in elongation εr (i) and the rate of actual difference in elongation ε.
Evaluation is made by the difference from (i).

A (i) = ε (i) −εr (i) −− (1) Equation (2) Shape change rate B (i) This is the change rate of the actual elongation difference rate ε (i) (direction of change).
Evaluate as.

B (i) = dε (i) / dt −−−− (2) Expression (3) Local elongation evaluation index C (i) This is an evaluation of the locally expanded portion due to the thermal crown.

C (i) = ε (i)-{(ε (i-1) + ε (i + 1)) / 2} --- (3) Formula (3) In Formula (3), (i + 1) is the length of the work roll. Is a detection position next to a position i in the vertical direction, and (I-
1) is the position before i.

The control output is determined by fuzzy inference from the above three evaluation values. The inference rules are: (1) If, if the control deviation A (i) is slightly negative, the shape change rate B (i) is slightly increasing in the positive direction, and the pole stretch evaluation index C (i) is zero. For example, cooling medium output α
(I) holds the current value.

(2) If, control deviation A (i) is zero, and shape change rate B
If (i) is greatly decreasing in the negative direction and the pole part elongation evaluation index C (i) is slightly large, the cooling medium output α
(I) is slightly reduced.

(3) If, the control deviation A (i) is slightly positive, the shape change rate B (i) is zero, and the pole portion elongation evaluation index C (i)
Is large and large, the cooling medium output α (i) is greatly increased.

(4) The following is omitted: A (i), B required to determine the cooling medium output α (i) which is the control output by using fuzzy reasoning in this way
The evaluation indexes such as (i) and C (i) are defined by using the membership function, one example of which is shown in FIG.

Figure 4A shows the membership function of the fuzzy variable with deviation A (i), Figure 4B shows the membership function of the fuzzy variable with rate of change B (i), and Figure 4C shows the local growth evaluation index C ( The membership function of the fuzzy variable of i) is shown. In these figures, "PB" is "Positive Big",
That is, it means "a group of positive and large numbers", and "PS" is "Positive Small", that is, a group of positive and small numbers.
"ZO" means "Zero", that is, "zero",
"NS" means "Negative Small", that is, "a group of negative and small numbers," and "NB" means "Negative Big," that is, a group of negative and large numbers. Using the above parameters, the inference rule, for example, the above inference rule (1) is If A (i) is NS and B (i) is PS a
nd C (i) is ZO, then Δα (i) is ZO. In this embodiment, it is necessary to create 74 types of such fuzzy control rules and 75 types in total. However, the control rules can be created by referring to the operation method of a skilled worker and the unnecessary rules can be appropriately deleted.
As an example, in the case of C (i) is ZO, the control output adjustment amount (Δ
α) The rule table is shown in Table 1 below.

The values of Δα (i) corresponding to the above PB to NB are as shown in Table 2.

According to this fuzzy control rule table, the cooling medium output α
The adjustment amount Δα (i) of (i) is calculated, and this adjustment amount Δα
(I) is added to the previous cooling medium output α ^* (i) to obtain the current cooling medium output α (i) as follows.

[alpha] (i) = [alpha] ^* (i) + [Delta] [alpha] (i) --- (4) Formula The injection pattern of the roll cooling medium is determined from this value, and the cooling medium output α (i) is sent to the valve command device 36.

FIG. 5 shows an example of a program when the cooling medium output calculation circuit 40 shown in FIG. 3 is realized by a microcomputer, which is started at a constant start cycle, for example, 1 second.

In the above embodiment, the injection of the roll cooling medium is performed by fuzzy inference using three fuzzy amounts of the difference in elongation difference A (i), the rate of change in elongation difference B (i), and the local evaluation index C (i). Although the pattern is determined, in the present invention, instead of using three fuzzy quantities at the same time, two fuzzy quantities of the above fuzzy quantities may be combined, and a new evaluation index may be added depending on the purpose. It may be added as a new fuzzy amount. Further, in the above embodiment,
Although it was a fuzzy control of 1 input (expansion difference rate) and 1 output (cooling medium output), multiple inputs (expansion difference rate and other sensor inputs) and multiple outputs (cooling medium output and other actuator output) fuzzy It can also be extended to control.

6 and 7 show modified examples of the actuator used in the present invention.

The actuator of FIG. 6 includes an external heating element 44 such as an induction heating coil or a high frequency heating element arranged side by side along the length of the work roll so as to heat a corresponding region from the outer surface of the work roll 14. Heating means 42
Made of. The control output obtained by the fuzzy inference is supplied to the external heating means to control the shape or state of the surface of the work roll and appropriately control the shape of the rolled plate 12.

The actuator of FIG. 7 is arranged in the work roll side-by-side in the longitudinal direction thereof so as to form a plurality of divided heating regions, for example, an induction heating coil, a high frequency heating element, an electric heating element, and It comprises an internal heating means 46 including a plurality of internal heating elements 48 such as steam flow tubes. The control output obtained by fuzzy inference is supplied to the internal heating element 48 to control the shape or state of the surface of the work roll 14 and appropriately control the shape of the rolled plate 12. The internal heating means 46 may be replaced with an internal cooling means including a plurality of internal cooling elements such as a cooling medium flow pipe, which are arranged in the work roll 14 side by side in the lengthwise direction of the work roll 14. The operating principle of the internal cooling means is exactly the same as the operating principle of the internal heating means 46.

8 to 10 show still another different modification of the present invention.

In the modification of FIG. 8, the shape control of the rolled plate material is performed by displacing one or both of the intermediate roll 16 and the work roll 14 in the length direction (axial direction) of the roll. Therefore, the actuator of this modified example is composed of displacement means for displacing the intermediate roll 16 or the work roll 14.
The control output obtained by the fuzzy inference is supplied to the displacement means to control the shape or state of the surface of the work roll 14 and appropriately control the shape of the rolled plate 12.

In the modification of FIG. 9, the shape control of the rolled plate material is performed by bending one or both of the intermediate roll 16 and the work roll 14 in the length direction (axial direction) of the roll. Therefore, the actuator of this modification includes the bending means 50 that applies the bending force BF to the intermediate roll 16 or the work roll 14. The control output obtained by fuzzy inference is
It is supplied to this bending means to control the shape or state of the surface of the work roll 14 and appropriately control the shape of the rolled plate material 12. The bending means 50 may be composed of a plurality of bending elements arranged in a divided state along the length direction of the roll 14 or 16 so that the area (zone) of the shape is controlled. .

In the modification of FIG. 10, the shape control of the rolled plate material is performed by changing at least one crown of the backup roll 18, the intermediate roll 16 and the work roll 14. Therefore, the actuator of this modification comprises crown changing means for changing the crown of the roll 18, 16 or 14. The control output obtained by the fuzzy inference is supplied to the crown changing means to control the shape or state of the surface of the work roll 14 and appropriately control the shape of the rolled plate 12. In the modification of FIG. 10, the backup roll 18
Has a crown changing means consisting of an oil-filled space 54 provided therein. In the illustrated embodiment, the backup roll 18 comprises a roll body 18A and a sleeve 18B provided on the roll body 18A, and the oil filled space 54 is
It is provided on the inner surface of the sleeve 18B. An oil introduction passage 56 is provided in the roll body 18A so as to communicate with the oil filling space 54. The crown changes according to the amount of oil filled in the oil filling space 54.

As can be seen from the modified examples of FIGS. 8 to 10, the actuator for controlling the shape or state of the surface of the work roll 14 has various modes as long as the shape of the rolled plate 12 can be controlled in the width direction thereof. can do.

In the illustrated embodiment, only one actuator is used to control the shape or condition of the surface of the work roll, but two or more actuators operated by fuzzy control are used to control the shape or condition of the surface of the work roll. It can be used to control. For example, a roll cooling means and a bending means can be combined and operated by fuzzy control.

〔The invention's effect〕

According to the present invention, like steam, the output signal from the shape detector is decomposed into a plurality of evaluation indexes, and the control output of the actuator is determined by fuzzy reasoning, so that various calculations can be performed without performing complicated calculations. There is a merit that the shape of the rolled sheet material can be accurately controlled by following changes in rolling conditions.

Further, the output signal of the shape detector is decomposed into a difference in elongation difference ratio, a rate of change in the elongation difference ratio, and a local elongation evaluation index, and these 3
Since at least two evaluation indexes out of the two evaluation indexes are used for fuzzy inference, the shape control is performed with higher accuracy than in the case where the shape parameter is simply obtained from the distribution of elongation in the plate width direction and the fuzzy control is performed. In particular, when the local elongation evaluation index is selected, it is possible to suppress the growth of the local elongation of the rolled material, which tends to occur during high speed rolling at a high reduction ratio, and significantly improve the overall shape.

[Brief description of drawings]

FIG. 1 is a system diagram of an apparatus used in a shape control method for a rolling mill according to the present invention, FIG. 2 is a system diagram of a roll cooling medium system as an actuator used in the present invention, and FIG. 3A is a target shape and rolling. A diagram showing the shape of the plate material, FIG. 3B is a diagram showing discrete values of the target differential expansion rate and the actual differential expansion rate, 4A to 4C.
FIG. 6 is a diagram showing the shape of the membership function, FIG. 5 is a flow chart when the method of the present invention is processed according to a computer program, and FIG. 6 is a work roll having an actuator used in another embodiment of the present invention. FIG. 7 is a perspective view, FIG. 7 is a cross-sectional view of a work roll having another actuator used in yet another embodiment of the present invention, and FIG. 8 is a front view of roll means controlled by another control method of the present invention. FIG. 9 is a side view of roll means controlled by still another control method of the present invention, and FIG. 10 is a sectional view of a backup roll used in another embodiment of the present invention. 10 …… Rolling machine, 12 …… Rolled plate material, 14 …… Work roll,
24 …… Cooling medium injection nozzle, 26 …… Shape detector, 34 ……
Valve device, 36 ... Valve command device, 38 ... Expansion difference rate calculation circuit,
40: Cooling medium output calculation circuit, 42: External heating means, 44
…… External heating element, 46 …… Internal heating means, 48 …… Internal heating element, 50 …… Bending means, 54 …… Oil filling space, 56 …… Oil introduction passage.

Front Page Continuation (72) Inventor Hiroshi Nagakura 21-2 Kurume, Mikuni-cho, Sakai-gun, Fukui Prefecture Furukawa Aluminum Industry Co., Ltd. Fukui Factory (72) Inventor Shigeru Hishikawa 21-2 Kurume, Mikuni-cho, Sakai-gun, Fukui Prefecture Aluminum Furukawa Fukui Factory, Kogyo Co., Ltd. (56) Reference JP-A-2-84211 (JP, A)

Claims (2)

(57) [Claims] 1. An actuator for controlling the shape or state of the surface of a rolling roll at the time of rolling, and a shape detector for detecting the shape in the width direction of a rolled plate material are provided, and the shape detector is provided in accordance with an output signal from the shape detector. In a rolling mill in which an actuator is operated to control the shape of the rolled sheet material, the output signal of the shape detector is decomposed into a plurality of evaluation indexes, which is obtained as a fuzzy amount, and the actuator is controlled by fuzzy inference. The amount of the rolled sheet material is controlled by controlling the amount, and the evaluation index includes a difference in elongation difference, a rate of change in the elongation difference, and a local elongation evaluation index, and at least two evaluation indexes out of the three evaluation indexes are included. A shape control method for a rolling mill, which is used for the fuzzy inference. 2. An actuator for controlling the shape or state of the surface of a rolling roll at the time of rolling and a shape detector for detecting the shape in the width direction of a rolled plate material are provided, and the shape detector detects the shape or state of the rolled plate material in the width direction. In a rolling mill in which an actuator is operated to control the shape of the rolled sheet material, the output signal of the shape detector is decomposed into a plurality of evaluation indexes, which is obtained as a fuzzy amount, and the actuator is controlled by fuzzy inference. Fuzzy inference means for determining a quantity is further provided, and the evaluation index includes a difference in elongation difference, a change rate of the difference in elongation ratio, and a local elongation evaluation index, and at least two evaluation indexes of the three evaluation indexes are the fuzzy. A shape control device for a rolling mill characterized by being used for inference.