JPH0440083B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a rolling mill control method and device, and more particularly, to a rolling mill control method and device for rolling a billet to a predetermined size by a rolling mill group equipped with grooved rolls. Relating to a rolling mill control method and device suitable for improving the dimensional accuracy of steel rods and wire rods by taking into consideration the configuration of the rolling mill group and the deformation form within the roll bite when obtaining steel rod and wire rod products with and shapes. .

(Prior Art) Generally, steel rods and wire rod products are obtained by continuous rolling using rolling mills equipped with slotted rolls. This rolling mill with grooved rolls is a tandem mill that has many types of grooves. Typical examples of the grooves are diamond groove, square hole, hexagonal hole, oval hole, and Round hole types are known. In this tandem mill, a billet as a rolled raw material is sequentially passed through a group of rolling mills equipped with various hole shapes to obtain a steel rod or wire rod as a final product.

By the way, rolling using grooved rolls mainly involves three-dimensional deformation, and requires complicated steps such as rolling in a direction perpendicular to the rolled material in sequence. For this reason, unlike rolling which mainly involves two-dimensional deformation such as rolling of plate materials, sufficient theory has been established to accurately calculate various rolling characteristic values including plastic deformation of the rolled material. Needless to say, this is a technical field that requires further improvement in accuracy in rolling setting calculations and rolling control.

On the other hand, in rolling with slotted rolls, three-dimensional deformation occurs mainly within the roll bite, and therefore, it is necessary to consider the dimension in the direction perpendicular to the direction of rolling (hereinafter referred to as the width direction) at the same time as the dimension in the rolling direction. There is. However, when rolling steel rods and wire rods using grooved rolls, the complexity of the mill configuration such as horizontal and vertical stands being arranged alternately, and the groove shape of the rolling rolls built into the stands itself. Due to the complexity of
The reality is that active dimensional control with a higher level of control than in sheet rolling is rarely performed, and improvements are also needed in terms of product quality.

In addition, even when implementing the conventional concept of AGC (automatic gain control) using simple reduction control or tension control,
Although it is naturally possible to control dimensions in the rolling direction as with sheet materials, it is not always possible to control dimensions in the width direction since rolling mainly involves three-dimensional deformation, and there is a large metal flow in the width direction at the same time as in the rolling direction. Dimensional accuracy is not guaranteed. In other words, when dimensional control in the rolling direction is carried out, the dimension in the width direction varies depending on the amount of reduction, the roll gap, and the tension, which makes it difficult to guarantee dimensional accuracy in rolling mills that roll and manufacture steel rods and wire rod products. There is.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to improve the rolling of steel rods and wire rods by means of slotted rolls, in addition to the longitudinal direction of the steel rods and wire rods. It is an object of the present invention to provide a rolling mill control method and device that can simultaneously control dimensions in the width direction at the same level.

[Structure of the invention]

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides rolling control of the first stand during continuous rolling alternately in the first direction and the second direction. Rolling down control is performed so that the exit side rolling dimension is a predetermined constant value, and the adjacent second stand on the upstream side is controlled by the deviation from the target value of the entry side rolling direction dimension and from the target value of the exit side rolling direction dimension. The dimension in the rolling direction on the exit side of the first stand is controlled by controlling the rolling down so that the sum with the deviation of is zero and by controlling the tension so that the first stand and the second stand have constant tension or no tension. The present invention provides a rolling mill control method for simultaneously controlling the dimension in the width direction and the dimension in the width direction orthogonal to the dimension in the rolling direction.

Further, the present invention includes a first stand that rolls a material to be rolled in a first direction, a second stand adjacent to the upstream side of the first stand that rolls a material to be rolled in a second direction, and a second stand that rolls a material to be rolled in a second direction. a first roll-down control means for adjusting the roll-down amount of the stand; a second roll-down control means for adjusting the roll-down amount of the second stand; and a dimension meter that measures the size of the entrance side of the second stand in the roll-down direction. , a first calculating means for calculating the difference between the detected value by the dimension meter and the target value, and a second calculating means for calculating the difference between the detected value by the dimension meter and the target value, and a second calculating means according to the output of the first calculating means.
a second calculating means for supplying a control signal to a second rolling control means so as to change the difference between the target value of the rolling direction dimension on the exit side of the stand and the rolling direction dimension on the exit side of the first stand; A rolling mill control device is provided that includes means for applying a control signal to the first rolling reduction control means so that the dimensions are constant.

(Function) Based on the above means, in the rolling mill control method and apparatus of the present invention, when rolling the material to be rolled three-dimensionally in the first direction and the second direction alternately, rolling reduction control in each direction is provided. By effectively implementing this, it is possible to precisely control dimensions in each direction.

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

FIG. 1 is a schematic configuration diagram of an apparatus for realizing a rolling mill control method according to an embodiment of the present invention. In particular, the case of three stand configurations # _i-2 , # _i-1 , and _#i is shown. This is an example. As shown in the figure, each stand # _i-2 , # _i-1 , _#i has rolling rolls 14, 13,
12, and continuously rolls the material 11 to be rolled.
Each rolling roll 14, 13, 12 has a drive motor 1.
are provided, and the rotation of these drive motors 1 is controlled by a motor control system consisting of a tachometer 2, a computer 4, and a rotation speed control device 3. Furthermore, the roll gap of the rolling roll 12 of stand _#i is controlled by a computer 140, a rolling down control device 15, and a rolling down device 16. On the other hand, the roll gap of the rolling roll 13 of stand # _i-1 is connected to a dimension meter 23 for measuring the dimension B _{i -2} ' of the rolled material 11 between stands # _i- 2 and # _i-1 , A setting device 20 for setting the width direction dimension B _i-2 after rolling of No. ₂ and the measured value of the dimension.
a calculator 21 that calculates the difference between B _i-2 ′ and the set value B _i-2 ;
This is the output of the setting device 19 for setting the rolling direction dimension h _i-1 of stand # _i-1 after rolling, and the arithmetic unit 21.
a calculator 22 that calculates the difference between B _i-2 ′−B _i-2 and the set value h _i-1 of the setting device 19 and sends h _i-1 ′;
It is controlled by a rolling down control device 17 which controls a rolling down device 18 which rolls down the rolling roll 13 based on a signal h _i-1 ' from the. Here, the setting device 19
The setting value h _i-1 of the setting device 20 and the setting value B _i-2 of the setting device 20 are calculated in advance by setting calculations to obtain the target product dimensions and shape from data such as the material, dimensions, temperature, etc. of the material before rolling. This is what has been done. This calculation is performed using a predetermined set calculation model formula or an empirical formula based on past operational results. Since this is a common practice in the field of rolling, a detailed explanation will be omitted. As is clear from FIG. 1, the rolling rolls 13 of stand # _i-1 are arranged vertically, and the rolling rolls 14 of stands # _i-2 , _#i ,
12 is arranged horizontally. For this reason, the rolled material 1
1 is rolled alternately in a first direction and a second direction.

Prior to explaining the operation of this configuration, the principle aspects will be explained.

First, in the configuration shown in FIG. 1, in stand _#i , the reduction control is performed by the computer 140, the reduction control device 15, and the reduction device 16 so that the dimensional deviation in the exit side reduction direction becomes zero. this is,
It is similar to conventional AGC.

On the other hand, in the adjacent upstream stand # _i-1 , the inlet dimension in the rolling direction with respect to the stand # _i-1 , that is, the exit width direction dimension of the adjacent upstream stand # _i-2 B _{i -2} 'Target value by setting device 20
The deviation B _{i-2 ′} −B _{i-2 from B i-2} is known by the dimension meter 23 and the calculator 21, and the stand # _i-2 is determined according to this deviation.
A reduction control device ₁₇ controls the reduction of the stand # _{i-1 so that the dimension in the reduction direction of the exit side of the stand #i-1} has a deviation from the target value h _i-1 determined by the setter 19 of the outlet side of the stand # _i-1 ;
This is carried out through a rolling down device 18. At this time,
It is assumed that the tension in the longitudinal direction of stand _#i and stand # _i-1 is controlled to a constant value or no tension, and a well-known tension control technique can be applied to this. Now, in such a rolling stand configuration, in rolling with slotted rolls, the dimension in the width direction changes depending on the amount of reduction in the rolling direction and the tension level.

First, regarding the stand _#i , the width direction dimension B _i of the exit side changes depending on the front tension t _if and the rear tension t _ib acting on the stand # _i during rolling. In other words,
When front or rear tension is applied, the exit side width direction dimension B _i is smaller than when the tension is zero.
Further, this width direction dimension B _i also changes depending on the rolling reduction amount of stand _#i (=roll gap=post-rolling dimension h _i of stand _#i in the rolling direction). In other words, the larger the reduction amount is, the larger the width dimension B _i becomes. When the above principle is expressed mathematically by incorporating the concept of influence coefficient, (1)
The formula is obtained.

ΔB _i /B _i =−(α _if Δt _if /k _i +α _ib Δt _ib /k _i )+γ _i
Δh _i /B _i …(1) holds true. However, ΔB _i =B _i ′−B _i …(2) Δh _i =(B _i-1 ′−B _i-1 )+(h _i ′−h _i )…(3). In addition, through equations (1), (2), and (3), ΔB _i is the deviation in the width direction of the exit side of stand _#i , B _i ′ is the width dimension of the exit side of stand _#i , and B _i is the width dimension of the exit side of stand _#i . Target width dimension,
Δh _i is the stand _#i reduction amount deviation, B _i-1 ′ is the stand # _i-1 outlet width dimension, B _i-1 is the stand # _i-1 outlet target dimension, h _i ′ is the stand # _i outlet pressure Downward dimension, h _i is stand _#i exit side target reduction direction dimension, α _if is influence coefficient of stand _#i front tension on width dimension, α _ib is influence coefficient of stand _#i rear tension on width dimension,
Δt _if is the front tension (stress) deviation of stand _#i , Δt _ib is the rear tension (stress) deviation _of stand _#i , γ _i is the influence coefficient of the reduction amount of stand _#i on the width dimension, and k _i is the This is the deformation resistance of rolled material. and,
The first term on the right side of equation (1) is the rate at which the width direction dimension B _i changes due to the deviation (that is, tension fluctuation) Δt _if of the front tension t _if , and the second term is the change rate of the width direction dimension B due to the rear tension deviation Δt _ib . _i means the rate of change, and these are given a minus sign. Note that the tension deviation Δt _if ′Δt _ib is made dimensionless by dividing it by the deformation resistance k _i of the material to be rolled. Further, the third term on the right side of equation (1) means the rate at which the width direction dimension B _i changes due to the reduction amount deviation Δh _i .

Regarding stand # _i-1 and stand # _i-2 ,
Similarly, the following relational expression holds true.

First, regarding stand # _i-1 , ΔB _i-1 /B _i-1 = −(α _(i-1)f Δt _(i-1)f /k _i-1 + α _(i-1)
b Δt _(i-1)b /k _i-1 )+γ _i-1 Δh _i-1 /B _i-1 (4). However, ΔB _i-1 = B _i-1 ′−B _i-1 …(5) Δh _i-1 = (B _i-2 ′−B _i-2 )+ (h _i-1 ′−h _i-1 ) …(6). On the other hand, for stand # _i-2 , ΔB _i-2 /B _i-2 = −(α _(i-2)f Δt _(i-2)f /k _i-2 +α _(i-2)
b Δt _(i-2)b /k _i-2 )+γ _i-2 Δh _i-2 /B _i-2 (7). However, ΔB _i-2 = B _i-2 ′−B _i-2 …(8) Δh _i-2 = (B _i-3 ′−B _i-3 ) +(h _i-2 ′−h _i-2 ) …(9). In formulas (4) to (9), the suffixes (i-1), (i-2), and (i-3) of each symbol indicate the stand number, and the meaning of each symbol is (1 ) to (3).

Now, in order for the dimensional deviation in the exit direction of stand _#i to be zero, if the dimension control in the exit side rolling direction of stand _#i and the tension control of stand _#i are implemented, ΔB _i =0 Δt _if = Δt The following conditions are required: _ib = 0 (10) h _i ′−h _i =0. Therefore, (1), (2), (3), (10)
From the formula, it is sufficient if B _i-1 ′−B _i-1 =0 (11). Next, if tension control of stand # _i-1 is implemented, Δt _(i-1)f = Δt _(i-1)b = 0 (12). Therefore, from equations (4), (5), (6), (11), and (12), h _i-1 ′−h _i-1 = −(B _i-2 ′−B _i-2 ) …( 13) It would be a good thing. i.e. stand # _i-1
If the reduction control of is carried out so as to satisfy equation (13),
The dimensional deviation in the width direction on the exit side of stand _#i is zero (ΔB _i =
0). The right side of equation (13) is the dimensional deviation in the rolling direction on the input side of stand # _i-1 , that is, the dimensional deviation in the width direction on the exit side of stand # _{i -2. Stand _ _ _ _} This means that the width direction dimension can be controlled at the same time as the exit side rolling direction dimension of _#i .

Now, in the configuration shown in FIG. 1, the tension between the stands # _i-2 , # _i-1 , and _#i of the material to be rolled 11 can be maintained at a constant tension or by controlling the rotational speed of the drive motor 1 through the control device 3. Controlled to a tension-free state. That is, Δt _if ′Δt _ib = Equations (1), (4), and (7)
It is controlled so that Δt _(i-1)f ′Δt _(i-1)b =Δt _(i-2)f becomes zero.

Note that in the configuration of FIG. 1, when stand _#i is the last stand, Δt _if =0, and also when loop amount control is performed between the stands, the tension between the stands is zero. While performing this inter-stand tension control, the rolling roll 12 of stand _#i is controlled by the rolling down control device 15 and rolling down device 16.
Roll gap control is carried out by the following, so that the dimensional deviation in the rolling direction of the rolled material 11 by the rolling rolls 12 on the exit side of stand _#i becomes zero, that is, h _i ′
-h _i =0. These tension control and reduction control are fully possible by known control methods.

On the other hand, the dimension gauge 23 installed between stand # _{i -1} and stand # _i-2, which are upstream stands of stand # i, measures the rolled material 1 rolled at stand # _i-2.
For stand #i-1, the width direction dimension B _i-2 ' of stand # _i-1 is detected. Arithmetic unit 21
The calculation of equation (8) is performed using this detected value B _i-2 ' and the target value B _{i -2 of the width direction dimension of the rolled material 11 after rolling of stand # i-} 2 set by the setting device 20. do. On the other hand, the setting device 19 is the stand # _i-1 of the material to be rolled 11.
The target value h _i-1 of the dimension in the rolling direction after rolling, that is, the target value of the dimension in the width direction on the entry side for stand _#i is set. The calculator 22 calculates the dimension h _i-1 ' in the rolling direction after rolling at stand # _i-1 as shown by equation (14). This reduction direction dimension h _i-1 ' is the reduction control device 1.
7 to control the rolling down device 18 of stand # _i-1 , that is, by controlling the roll gap of stand # _i-1 .

By implementing such control, in other words, the rolling reduction amount of the adjacent upstream stand of the stand is controlled so that the dimension in the exit side rolling direction has a deviation value according to the dimensional deviation on the entry side, and in the relevant stand, the rolling amount in the exit side rolling direction is controlled. By controlling the reduction amount so that there is no deviation value in the dimensions, as a result, the rolled material 1 on the exit side of the stand
This makes it possible to simultaneously control the dimension in the rolling direction and the dimension in the width direction.

FIG. 2 is an explanatory diagram showing a state in which the rod is passed through, where the material to be rolled 11 has not reached stand _#i . The part surrounded by dotted lines in Figure 2 is the setting device 1 shown in Figure 1.
9, 20, and adders 21 and 22 collectively, the controller 24 is a part that can be provided with this function in a computer.

Now, h _(i-1)0 ′ and B _(i-1)0 ′ in Fig. 2 are the dimensions in the rolling direction and the width direction of the exit side of stand # _i-1 in the state shown in Fig. 2. # There is no forward tension in _i-1 . B _(i-2)0 ' is the width dimension after rolling at stand # _i-2 , and t _(i-1)b0 is the tension between stand # _i-2 and stand # _i-1 .

Next, Figure 3 shows stand _#i from the state in Figure 2.
The state in which the material to be rolled 11 has reached is shown, and the tension between stand # _i-1 and stand _#i becomes t _ib , and due to the generation of this tension, the dimension in the rolling direction on the exit side of stand # _i-1 becomes h _{(i- 1)0} ″, B _(i-1)0 ″, and the width direction dimension of stand # _i-2 exit side is B _(i-2) ″, between stand # _i-2 and stand # _i-1. This shows that the tension has become t _i-1)b ′.The lowering control of stand # _{i-1 in Fig. 2 and stands # i- 1} and stand # _i in Fig. 3 are as shown in Fig. 1. It is carried out in exactly the same way.

That is _, in _{the state shown in FIG . -1} Δh _(
i-1)0 /B _i-1 ΔB _i-1 =B _(i-1)0 ′−B _i-1 …(4)′ Δh _(i-1)0 = (B _(i-2)0 ′ −B _i-2 )+(h _(i-1)0 ′−h _i-1
) In the state shown in Figure 3, the exit side of stand # _i-1 is ΔB _i-1 ′/B _i-1 = −(α _(i-1)b t _(i-1)b ′/k _i-1 +α _(i-
1)f t _ib /k _i-1 ) +γ _i-1 Δh _(i-1)0 ′/B _i-1 …(4)″ ΔB _i-1 ′=B _(i-1)0 ″−B _{i -1} Δh _(i-1)0 ′=(B _(i-2)0 ″−B _i-2 )+(h _(i-1)0 ″−h _i-
1 ), and the exit side of stand _#i is ΔB _i /B _i =−α _ib t _ib /k _i =γ _i Δh _i /B _i …(1)′ ΔB _i =B _i ′−B _i . However, Δh _i in formula (1)′ is Δh _i = (B _(i-1)0 ′−B _i-1 ) + (h _i '−h _i ) ...(14), and for the state shown in Fig. 3, that is, the rolled material 11 that has been rolled after being bitten by stand _#i , Δh _i = (B _{( i-1)0} ″−B _i-1 ) + (h _i ′−h _i ) …(15) By controlling the pressure of stand _#i , h _i ′−h _i =
0 and ΔB _i = 0, equation (1)′ and
From equation (14), −α _ib t _ib /k _i +γ _i B _(i-1)0 ′−B _i-1 /B _i =0 …(16), and from equations (1)′ and (15), −α _ib t _ib /k _i +γ _i B _(i-1)0 ″−B _i-1 /B _i =0 …(17) It is only necessary to control so that the equations (4)′ and (16) From 1/B _i-1・B _i /γ _i α _ib t _ib /k _i =−α _(i-1)b t _(i-1)b /k
_i-1 +γ _(i-1)0 Δh _(i-1)0 /B _i-1 …(18) Δh _(i-1)0 = (B _(i-2)0 ′−B _i-2 )+ (h _(i-1)0 ′−h _i-1
) becomes. Here, as explained in FIG. 1, it is possible to set Δh _(i-1)0 = 0 by controlling the reduction of stand # _i-1 , so equation (18) can be expressed as t _ib /t _{( i-1)b} = −α _(i-1)b /k _i-1 1/B _i-1・B _i /γ _i α
_ib 1/k _i …(19). Next, from equations (4)″ and (17), 1/B _i-1・B _i /γ _i α _ib t _ib /k _i =−α _(i-1)b t _(i-1)b ′
/k _i-1 −α _(i-1)f t _ib /k _i-1 +γ _i-1 Δh _(i-1)0 ′/B _i-1 …(20
) Δh _(i-1)0 ′=(B _(i-2)0 ″−B _i-2 )+(h _(i-1)0 ″−h _i-
1 ). Here, as explained in Fig. 1, it is possible to set Δh _(i-1)0 ' = 0 by controlling the reduction of stand # _i-1 , so equation (20) can be expressed as t _ib /t _(i-1)b ′=−α _(i-1)b /k _i-1 (1/B _i-1・B _i /γ
_i α _ib 1/k _i +α _(i-1)f /k _i-1 )...(21).

That is, in the rod passing state shown in FIGS. 2 and 3, in order to guarantee the dimensional accuracy in the rolling direction and width direction on the exit side of stand _#i , which is the stand concerned, rolling in the state shown in FIG. rolled material 1
1, that is, for the rolled material 11 that is between stand # _i-1 and stand # _i and has passed through stand # _i-1 with no tension between each stand # _i-1 and # _i . is such that it satisfies equation (19), that is, after the tip of the rolled material 11 is bitten by stand _#i , t _ib of equation (19)
Tension control is performed so that the tension becomes the tension between stand # _i-1 and stand _#i , and the tip of the rolled material 11 rolled in the state shown in Fig. 3, that is, stand _#i , is caught in stand _#i. The tension between _-1 and stand _#i is
Rolled material 11 passed through stand # _i-1 in the state of t _ib
In this case, tension control may be performed so that equation (21) is satisfied, that is, t _ib calculated by equation (21) becomes the tension between stand # _i-1 and stand _#i .

In other words, in FIGS. 2 and 3, the means and method for simultaneously guaranteeing the dimension in the rolling direction and the dimension in the width direction when the material to be rolled 11 is bitten, that is, when passing through the rod, are illustrated, but conversely, the dimension in the rolling direction and the dimension in the width direction are It is possible to control the dimensions in each direction in the same way even when cutting through.

It is also possible to perform dimensional control by controlling the tension between the stands using formulas (1) to (9) as basic calculation formulas while controlling stand # _i-1 to be rolled down in the same way as stand _#i . be.

〔Effect of the invention〕

As described above, according to the present invention, in a steel bar or wire rod mill in which a material to be rolled is rolled alternately from the vertical direction and from the left and right, the dimensional accuracy in the width direction is improved at the same time as in the rolling direction. It is possible to obtain a rolling mill control method and device that can be guaranteed from start to finish and that can improve the dimensional accuracy and yield of steel rods and wire rods.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus for realizing a rolling mill control method according to an embodiment of the present invention, and FIGS. It is an explanatory diagram. DESCRIPTION OF SYMBOLS 11... Material to be rolled, 12, 13, 14... Rolling roll, 15, 17... Rolling down control device, 16, 18... Rolling down device, 19, 20... Setting device, 21, 22... Arithmetic unit, 23... Dimension meter, 24 …calculator.

Claims (1)

[Claims] 1. In rolling a steel bar or rolling a wire rod, in continuous rolling in a first direction and a second direction that are perpendicular to each other in a plane perpendicular to the conveyance direction of the material to be rolled,
The rolling down control of the first stand is performed so that the exit side rolling direction dimension is a predetermined constant value. The reduction control is performed so that the sum of the deviation from the target value of the side reduction direction dimension is zero, and the tension control is performed so that the first stand and the second stand have constant tension or no tension. A rolling mill control method characterized by simultaneously controlling a dimension in the rolling direction on the exit side of a stand and a dimension in a direction perpendicular to the dimension in the rolling direction. 2. In steel bar rolling or wire rod rolling, in a device that continuously rolls the material to be rolled in a first direction and a second direction that are perpendicular to each other in a plane perpendicular to the conveyance direction of the material to be rolled, the material to be rolled is rolled in the first direction. a first stand; a second stand adjacent to the upstream side of the first stand and rolling the material to be rolled in a second direction;
A first roll-down control means for adjusting the roll-down amount of the first stand, a second roll-down control means for adjusting the roll-down amount of the second stand, and a size of the entrance side of the second stand in the roll-down direction. a dimension meter, a first calculation means for calculating a difference between a value detected by the dimension meter and a target value thereof, a difference calculated by the first calculation means, and a dimension in the rolling direction on the exit side of the second stand. a second calculation means for supplying a control signal to the second reduction control means so that the sum of the difference from the target value becomes zero;
A rolling mill control device comprising means for applying a control signal to the first rolling reduction control means so that the dimension in the rolling direction on the exit side of the first stand is a constant value.