JP2005125329A - Rolling method by multi-strand rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling method by a multi-strand rolling mill capable of performing rolling with high accuracy. <P>SOLUTION: In the rolling method by a multi-strand rolling mill to perform rolling by individual rolling lines of A train and B train branched from a common rolling line 101 after simultaneously performing rolling by the common rolling mill train 101, a loop is formed in repeaters 105A and 105B, the height of the loop is detected, and rolling is performed by controlling the speed of the rolling mill of the common rolling line 101 based on the detected loop height. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rolling method using a multi-strand rolling apparatus having a function of simultaneously rolling a plurality of rolled materials such as wire rods and steel bars. Specifically, the present invention relates to a rolling method by a multi-strand rolling apparatus that performs rolling on a plurality of individual rolling lines branched from the common rolling line after simultaneously rolling a plurality of materials to be rolled on the common rolling line.

A rolling facility for rolling and manufacturing wire rods or bar steels is generally composed of a rough rolling mill row, an intermediate rolling mill row, and a finishing rolling mill row in order from the upstream side. Each rolling mill row includes a plurality of rolling stands ( Rolling mill).
In recent years, multi-strand rolling apparatuses having a function of simultaneously rolling a plurality of materials to be rolled have been used (see, for example, Patent Document 1).

  FIG. 3 shows an example of a multi-strand rolling apparatus having a two-row configuration. The material to be rolled supplied in two rows is rolled by a common rolling mill up to a first rolling mill row consisting of a rough rolling mill row 102 consisting of rolling stands 0 to 8 and a rolling stand 9 to 15; It is branched and rolled into a row and a B row. That is, in row A, after being rolled in second intermediate rolling mill row 104A composed of rolling stands 16A and 17A, rolling is performed in finish rolling mill row 106A composed of rolling stands 18A to 22A. Further, in the B row, after being rolled in the second intermediate rolling mill row 104B including the rolling stands 16B and 17B, the rolling is performed in the finish rolling mill row 106B including the rolling stands 18B to 22B.

  Between the first intermediate rolling mill row 103 and the second intermediate rolling mill rows 104A and 104B, first repeaters 105A and 105B are provided between the second intermediate rolling mill row 104A and 104B and the finishing rolling mill rows 106A and 106B. Are provided with second repeaters 107A and 107B. With these repeaters, by forming appropriate loops in the material to be rolled between the first intermediate rolling mill row and the second intermediate rolling mill row and between the second intermediate rolling mill row and the finishing rolling mill row, a rolling stand The dimensional accuracy of the material to be rolled is made good by suppressing the tension and compression force between them.

  Then, as a method of controlling the loop amount (hereinafter referred to as “loop height”) to be constant, the loop height formed by the first repeaters 105A and 105B is detected, and each of the preset loop heights is detected. The deviation from the target value is calculated, and the second intermediate rolling mill rows 104A and 104B on the downstream side of the repeaters 105A and 105B as shown by the symbol C in FIG. 3 so that the loop height deviation becomes zero. A speed correction signal is given to the rolling stand to correct the speed (roll rotation speed) of the rolling stand. Similarly, in the second repeaters 107A and 107B, the loop height is detected, the deviation from the preset loop height target value is calculated, and the loop height deviation becomes zero. As indicated by reference numeral D in FIG. 3, a speed correction signal is given to the rolling stands of the finish rolling mill rows 106A and 106B on the downstream side of the repeaters 107A and 107B to correct the rolling stand speed (roll rotation speed). Has been done. So-called downstream control is performed.

JP-A-8-267116 (pages 2-7)

  However, in the downstream control described above, the loop height deviation on the upstream side is finally adjusted according to the speed (roll rotation speed) of the rolling stand in the finish rolling mill row. As a result, the speed (rolling speed) of the rolling stand of the finish rolling mill is corrected and changed during rolling, and this speed fluctuation causes the finishing dimension to vary, which makes it difficult to perform highly accurate rolling. It was.

  The present invention has been devised in view of the above points, and an object of the present invention is to provide a rolling method using a multi-strand rolling apparatus that enables high-precision rolling.

  The inventor has made various studies in order to solve the above-described problems, and has obtained the following knowledge.

  (A) When loop height deviation is detected, so-called upstream control that corrects the speed of the upstream rolling stand based on this loop height deviation is adopted, so that the rolling stand of the finishing mill row during rolling It is not necessary to vary the speed, and as a result, the accuracy of the finished dimensions of the product can be ensured.

  (B) When the upstream control is adopted in the multi-strand rolling apparatus, there is a concern about interference of the speed correction signal at the upstream common rolling stand. However, the speed correction signals from multiple rows of loop heights after branching use the maximum loop height and the minimum loop height of each loop height, for example, the maximum loop height and the minimum loop height center height. It is possible to minimize the problem of interference of the speed correction signal by setting the speed correction signal so as to be close to the target height or to be the target height.

  (C) forming a first loop for each individual rolling line on the material to be rolled between the common rolling line and a plurality of individual rolling lines that branch, and forming a second loop on the material to be rolled in each individual rolling line; In the rolling apparatus having a plurality of loops, when the loop height of the first loop exceeds a predetermined allowable range, the condition for controlling the speed of the upstream rolling mill by the loop height of the second loop, For example, the loop height of the first loop can be changed by changing the target height of the second loop.

  In order to achieve the above object based on the above knowledge, the rolling method by the multi-strand rolling apparatus according to the present invention is to roll a plurality of materials to be rolled at the same time on a common rolling line, and then from the common rolling line. A rolling method using a multi-strand rolling device that performs rolling at a plurality of branched individual rolling lines, forming a loop on a material to be rolled between predetermined rolling mills, detecting the height of the loop, and detecting the detected loop The rolling is performed by controlling the speed of the rolling mill on the upstream side of the loop based on the height.

  In the rolling method using the multi-strand rolling apparatus according to the present invention, a loop is formed for each individual rolling line in the material to be rolled between the common rolling line and the plurality of individual rolling lines that branch, The height of the loop is detected, and rolling is performed by controlling the speed of the rolling mill of the common rolling line based on the maximum loop height and the minimum loop height among the detected loop heights.

  In addition, the control of the speed of the rolling mill of the common rolling line based on the maximum loop height and the minimum loop height, for example, the center height of the maximum loop height and the minimum loop height is close to a predetermined target height, Furthermore, the center height of the maximum loop height and the minimum loop height may be set to a predetermined target height.

  The rolling method using the multi-strand rolling apparatus according to the present invention is a multi-strand in which a plurality of materials to be rolled are simultaneously rolled in a common rolling line and then rolled in a plurality of individual rolling lines branched from the common rolling line. A rolling method using a rolling apparatus, wherein a first loop is provided for each individual rolling line in the material to be rolled between the common rolling line and a plurality of individual rolling lines that branch, and the material to be rolled in each individual rolling line is Two loops are formed, the height of each loop is detected, rolling is performed by controlling the speed of the rolling mill upstream of the loop based on the detected loop height, and the loop height of the first loop is When exceeding a predetermined allowable range, the condition for controlling the speed of the upstream rolling mill according to the loop height of the second loop is changed. As a condition for controlling the speed of the upstream rolling mill according to the loop height of the second loop, for example, the loop height target value of the second loop may be used.

  As described above, the rolling method using the multi-strand rolling apparatus of the present invention enables highly accurate rolling.

  Hereinafter, each requirement of the present invention will be described.

  A rolling method using a multi-strand rolling apparatus according to the present invention includes forming a loop in a material to be rolled between predetermined rolling mills, detecting the height of the loop, and upstream of the loop based on the detected loop height. It is the structure which performs what is called upstream control which controls the speed of the side rolling mill. As a result, it is not necessary to change the speed of the rolling stand of the finish rolling mill row during the rolling for the loop height control, and the speed fluctuation of the rolling stand can be suppressed, so that highly accurate rolling can be realized. it can.

  Further, the rolling method by the multi-strand rolling apparatus according to the present invention is to form a loop for each individual rolling line in the material to be rolled between the common rolling line and the plurality of individual rolling lines branched, The height of the loop is detected, and rolling is performed by controlling the speed of the rolling mill of the common rolling line based on the maximum loop height and the minimum loop height among the detected loop heights. As a result, the loop height of a plurality of individual rolling lines can be controlled by the speed of the common rolling stand while minimizing interference problems. As a result, it is not necessary to change the speed of the rolling stand of the finish rolling mill row during the rolling for the loop height control, and the speed fluctuation of the rolling stand can be suppressed, so that highly accurate rolling can be realized. it can.

  Control of the rolling mill speed of the common rolling line based on the maximum loop height and the minimum loop height, for example, the central height of the maximum loop height and the minimum loop height is brought close to a predetermined target height, By controlling the center height of the maximum loop height and the minimum loop height to a predetermined target height, control of the loop height of multiple individual rolling lines can be minimized. However, it can be done very easily depending on the speed of the common rolling stand.

  The rolling method using the multi-strand rolling apparatus according to the present invention is a multi-strand in which a plurality of materials to be rolled are simultaneously rolled in a common rolling line and then rolled in a plurality of individual rolling lines branched from the common rolling line. A rolling method using a rolling apparatus, wherein a first loop is provided for each individual rolling line in the material to be rolled between the common rolling line and a plurality of individual rolling lines that branch, and the material to be rolled in each individual rolling line is Two loops are formed, the height of each loop is detected, rolling is performed by controlling the speed of the rolling mill upstream of the loop based on the detected loop height, and the loop height of the first loop is When exceeding a predetermined allowable range, the condition for controlling the speed of the upstream rolling mill according to the loop height of the second loop is changed. By adopting this configuration, even when the control of the loop height of the first loop becomes difficult to control due to the speed of the common rolling stand upstream thereof, in combination with the height control of the second loop, It is possible to perform the loop height control of the first loop.

  The condition for controlling the speed of the upstream rolling mill according to the loop height of the second loop can be easily achieved by using, for example, the loop height target value of the second loop. For example, when the loop height of any one of the first loops of the individual rolling line exceeds a predetermined allowable range, the loop height target value of the second loop is changed to the larger one. Then, control is performed so that the speed of the rolling mill upstream from the second loop of the individual rolling line is increased in order to satisfy the increased loop height target value of the second loop. As a result, the loop height of the first loop is controlled to be small. As a result, the loop height control of the first loop can be performed within a predetermined allowable range.

  Examples of the present invention will be described below for understanding of the present invention.

  FIG. 1 is a schematic diagram showing an example of a rolling method using a multi-strand rolling apparatus to which the present invention is applied. The material to be rolled supplied in two rows is rolled in a common rolling mill row 101 up to a rough rolling mill row consisting of rolling stands 0 to 8 and a first intermediate rolling mill row consisting of rolling stands 9 to 15; Branched into A row and B row and rolled. That is, in row A, after being rolled in second intermediate rolling mill row 104A composed of rolling stands 16A and 17A, rolling is performed in finish rolling mill row 106A composed of rolling stands 18A to 22A. Further, in the B row, after being rolled in the second intermediate rolling mill row 104B including the rolling stands 16B and 17B, the rolling is performed in the finish rolling mill row 106B including the rolling stands 18B to 22B.

  Between the first intermediate rolling mill row 103 and the second intermediate rolling mill rows 104A and 104B, first repeaters 105A and 105B are provided between the second intermediate rolling mill row 104A and 104B and the finishing rolling mill rows 106A and 106B. Are provided with second repeaters 107A and 107B. By these repeaters, a first loop and a second loop are formed on the material to be rolled between the first intermediate rolling mill row and the second intermediate rolling mill row and between the second intermediate rolling mill row and the finishing rolling mill row, respectively. .

  An example of a method for rolling the material to be rolled while controlling the loop height to be constant will be described below.

First, the loop height control of the first loop will be described. The first loop height formed by the first repeater 105A in row A is a1, the first loop height formed by the first repeater 105B in row B is b1, and the loop height target formed by the first repeater When the value is s1, the speed before correction of the rolling stand of the common rolling mill row 101 is V0, the speed correction amount is Vdx, and the speed after correction is Vx,
Vx = V0 + Vdx
Vdx = K1 [s1-{(a1 + b1) / 2}] (K1 is a constant)
Control is performed so that the above condition is satisfied.
By appropriately determining K1, the center height (a1 + b1) / 2 of the maximum loop height and the minimum loop height can be controlled to approach the target height s1.

Next, the loop height control of the second loop will be described. The second loop height formed by the second repeater 107A in the A row is a2, the target value of the loop height is sa2, the speed before correction of the rolling stand of the second intermediate rolling mill row 104A is Va0, and the speed correction amount is Vadx and the corrected speed are Vax. Further, the second loop height formed by the second repeater 107B in the B row is b2, the target value of the loop height is sb2, the speed before correction of the rolling stand of the second intermediate rolling mill row 104B is Vb0, and the speed correction. The amount is Vbdx, and the corrected speed is Vbx. in this case,
Vax = Va0 + Vadx
Vadx = Ka2 [sa2-a2] (Ka2 is a constant)
Vbx = Vb0 + Vbdx
Vbdx = Kb2 [sb2-b2] (Kb2 is a constant)
The second loop height may be individually controlled in the A column and the B column so as to satisfy the above condition.

  FIG. 2 is a schematic diagram relating to a loop height control method of the first loop of the multi-strand rolling apparatus to which the present invention is applied. Hereinafter, the concept of the loop height control method of the first loop of the multi-strand rolling apparatus to which the present invention to which the present invention is applied is applied will be described.

(1) When the loop height of row A and row B is within the allowable range limit (FIGS. 2A and 2B)
The first loop height a1 in the A row and the first loop height b1 in the B row are displaced in the same direction as the case (FIG. 2A) with respect to the loop height target value s1. There is a case (FIG. 2B). In either case, control is performed so that the center d1 (= (a1 + b1) / 2) of the first loop height in the A row and the B row becomes the loop height target value s1.
The speed correction amount Vdx of the rolling stand in this case is as follows.
Vdx = K1 [s1-{(a1 + b1) / 2}] (K1 is a constant)

(2) When the loop height of row A and row B approaches the allowable range limit (FIG. 2 (c))
In the control that makes the center of the loop height approach the loop height target value or the loop height target value when the deviation width of the first loop height in the A row and the B row is excessive. It is difficult to eliminate this deviation width.
In this case, for example, an allowable range h0 is defined for the deviation width h1 (= a1-b1) of the first loop height in the A and B rows, and when the deviation width h1 of the first loop exceeds the allowable range h0, the deviation width What is necessary is just to change the target value of the 2nd loop height (loop height of 2nd repeater 107A, 107B) of any one or both of A row and B row so that h1 may become small. For example, in the case of a1> b1, a change such as increasing the target value of the second loop height of the A column or decreasing the target value of the second loop height of the B column may be performed. By this change, in the A row, the speed of the rolling stand of the second intermediate rolling mill row 104A is corrected in the direction of increasing, and the first loop height a1 is controlled in the decreasing direction. In the B row, the speed of the rolling stand of the second intermediate rolling mill row 104B is corrected so as to decrease, and the first loop height b1 is increased. When the deviation width h1 of the first loop height exceeds the allowable range h0 by changing the target value of the second loop height, the deviation width h1 can be reduced.

  When the deviation width h1 is within a predetermined range, normal control is performed so that the center d1 (= (a1 + b1) / 2) of the first loop height in the A row and the B row approaches the loop height target value s1. Just do it.

  Moreover, what is necessary is just to control as follows in the case of the multi strand rolling apparatus branched to n row | line | column (N1 row | line | column, N2 row | line | column, ..., Ni row | line | column, ..., Nn row | line).

In the loop height control of the first loop, the first loop height formed by the first repeater 105Ni in the Ni row is Xi1, the target value of the loop height formed by the first repeater is s1, and the common rolling mill row When the speed before correction of the 101 rolling stand is V0, the speed correction amount is Vdx, and the speed after correction is Vx,
Vx = V0 + Vdx
Vdx = KN1 [s1-{(X1max + X1min) / 2}] (KN1 is a constant)
X1max = MAX (X11, X21,..., Xi1,..., Xn1) (i = 1 to n)
X1min = MIN (X11, X21,..., Xi1,..., Xn1) (i = 1 to n)
MAX means taking the maximum value, and MIN means taking the minimum value. That is, in the case of a multi-strand rolling apparatus having an n-row configuration (n ≧ 3), for example, as described above, the maximum loop height X1max formed by the first repeater in the n-row, and n By using the minimum loop height X1min formed by the first repeater in the row, the same control as that of the multi-strand rolling device having a two-row configuration can be achieved.

As for the second loop height, the second loop height formed by the second repeater 107Ni for each row is Xi2, the target value of the loop height is si2, and the rolling stand of the second intermediate rolling mill row 104Ni. The speed before correction is Vb0, the speed correction amount is Vbdx, and the speed after correction is Vbx. in this case,
Vnix = Vni0 + Vnidx
Vnidx = Kni2 [si2-Xi2] (Kni2 is a constant, i = 1 to n)
Individual control may be performed to satisfy the above condition.

  For example, when the deviation width h1 (= X1max−X1min) of the first loop height exceeds the allowable range h0, the maximum loop height row and the minimum loop height row so that the deviation width h1 becomes small. The target value of either or both of the second loop heights (the loop height of the second repeater) may be changed. For example, the target value of the second loop height of the row with the maximum loop height may be increased, or the target value of the second loop height of the row with the minimum loop height may be changed. With this change, the maximum loop height row is corrected in the direction in which the speed of the rolling stand of the second intermediate rolling mill row is increased, and is controlled in the direction in which the first loop height is reduced. Moreover, in the row | line | column of minimum loop height, it correct | amends in the direction where the speed of the rolling stand of a 2nd intermediate rolling mill row | line becomes small, and is controlled by the direction which makes 1st loop height large. When the deviation width h1 of the first loop height exceeds the allowable range h0 by changing the target value of the second loop height, the deviation width h1 can be reduced.

  In addition, it cannot be overemphasized that the control formula for the speed correction of the rolling stand for controlling the loop height uniformly in the multi-strand rolling apparatus to which the present invention is applied is only an example. By appropriately setting this speed correction control expression, it is also possible to control the center of the loop height of a plurality of rows as the target value of the loop height.

  Further, in the method of rolling the material to be rolled by controlling the loop height constant in the multi-strand rolling apparatus to which the present invention is applied, a common rolling mill row (rough rolling mill row and first intermediate rolling mill row) Although an example is shown in which a repeater is provided in two places between the second intermediate rolling mill row and between the second intermediate rolling mill row and the second rolling mill row to form a loop and control the loop height. Needless to say, it is not always necessary that the number of loops formed by the above-mentioned is two, but it can also be implemented in a multi-strand rolling apparatus that forms three or more loops and rolls the material to be rolled while controlling the height of the loops.

  In the rolling method by the multi-strand rolling apparatus to which the present invention is applied, as described above, rolling is performed while controlling the loop height in the repeater without changing the speed of the rolling stand (roll rotation speed) of the finish rolling mill row. be able to. As a result, it is possible to expect effects such as improvement of the dimensional accuracy of the product, improvement of the winding shape, reduction of the length of uncooled cooling, and extension of the life of the rolling stand of the finish rolling mill row.

  Further, since the speed of the rolling stand that immediately brings the centers of the loop heights of the plurality of rows close to the target value of the loop height is corrected, stable and highly accurate product supply becomes possible.

It is a schematic diagram which shows an example of the rolling method by the multi strand rolling apparatus to which this invention is applied. It is a schematic diagram regarding the loop height control method of the 1st loop of the multi strand rolling apparatus to which this invention is applied. 1 shows an example of a multi-strand rolling device having a two-row configuration.

Claims (4)

A rolling method by a multi-strand rolling apparatus that performs rolling at a plurality of individual rolling lines branched from the common rolling line after simultaneously rolling a plurality of materials to be rolled at a common rolling line,
Forming a loop on the material to be rolled between predetermined rolling mills, detecting the height of the loop, and rolling by controlling the speed of the rolling mill upstream of the loop based on the detected loop height A rolling method using a multi-strand rolling apparatus. A loop is formed for each individual rolling line on the material to be rolled between the common rolling line and a plurality of individual rolling lines branched, and the height of the loop for each individual rolling line is detected, and the detected loop height The rolling method using a multi-strand rolling apparatus according to claim 1, wherein the rolling is performed by controlling the speed of the rolling mill of the common rolling line based on the maximum loop height and the minimum loop height. The multi-strand according to claim 2, wherein rolling is performed by controlling the speed of the rolling mill of the common rolling line so that the center height of the maximum loop height and the minimum loop height approaches a predetermined target height. A rolling method using a rolling device. A rolling method by a multi-strand rolling apparatus that performs rolling at a plurality of individual rolling lines branched from the common rolling line after simultaneously rolling a plurality of materials to be rolled at a common rolling line,
A first loop is formed for each individual rolling line in the material to be rolled between the common rolling line and the plurality of individual rolling lines that branch, and a second loop is formed in the material to be rolled in each individual rolling line. When the height is detected and rolling is performed by controlling the speed of the rolling mill upstream of the loop based on the detected loop height, and when the loop height of the first loop exceeds a predetermined allowable range, A rolling method using a multi-strand rolling apparatus, wherein conditions for controlling the speed of the upstream rolling mill according to the loop height of the second loop are changed.

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