JPH05123B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a strip width control device for a hot rolling mill that passes a metal material heated to a high temperature between rotating rolls to obtain a predetermined strip width. It is.

[Conventional technology]

FIG. 3 is a diagram schematically showing a conventional plate width control device disclosed in, for example, Japanese Patent Publication No. 50-24907.
In the figure, 1 is a metal material, 2 is a vertical roll of a rough rolling mill, 3 is a horizontal roll of a rough rolling mill installed immediately after this vertical roll, and metal material 1 is rolled into a predetermined plate by this horizontal roll and vertical roll 2. After being formed into a width, it is continuously rolled in a downstream finishing mill. 4 is a board width meter; 5 is a board width pattern determination storage device that sequentially stores the width of the metal material 1 measured by this board width meter in the longitudinal direction of the metal material 1; 6 is a vertical roll position calculation device; Vertical roll position control device that controls the position of the vertical roll 2 according to the roll position derived by the vertical roll position calculation device; 8 is a setting device that sets various setting values; 9 is a required strip width calculation device before rolling; 10 11 is a vertical roll position measuring device that measures the position of the vertical roll 2 and provides feedback to the vertical roll position control device 7; 11 is a required strip width pattern calculation device before rolling;
Reference numeral 12 denotes a width correction amount calculation device which derives a width correction amount from the deviation between the strip width pattern derived by this pre-rolling required strip width pattern calculation device and the strip width pattern in the strip width pattern determination storage device 5, and 13 a vertical roll. This is a jump amount calculation device.

Next, the operation will be explained. The setter 8 sets the target sheet width B _S for the metal material 1 at the exit side of the horizontal rolls 3 of the rough rolling mill. This target plate width B _S
is supplied to the pre-rolling required plate width pattern calculation device 11 through the pre-rolling required plate width calculation device 9, and the pre-rolling required plate width pattern calculation device 11 calculates the target plate width.
Calculate the required strip width pattern before rolling B _SO from B _S.
On the other hand, the width B of the metal material 1 before rolling was actually measured using a width gauge 4 installed on the inlet side of the vertical roll 2 of the rough rolling mill.
The plate width pattern in the longitudinal direction of the metal material 1 is stored in the plate width pattern determination storage device 22. This actual value B
The width correction amount calculation device 12 calculates the difference between the required plate width pattern before rolling B _SO as ΔB _o =B−B _SO to obtain the width correction amount ΔB _o . Once the width correction amount ΔB _o is determined, the jump amount ΔS of the vertical roll is calculated as a function of this correction amount ΔB _o , the target plate thickness B _S set by the setter 8, and the deformation resistance. Here, the deformation resistance is determined by the material, temperature, etc. of the metal material. The vertical roll jump amount △S is the vertical roll when the vertical roll 2 is biting the metal material 1 from the position where the vertical roll 2 was set before the metal material 1 is biting into the vertical roll 2 and being rolled. This refers to the amount of movement to position 2, and varies depending on the amount of wear on the bearings that support the shaft of the vertical roll 2, the amount of elastic deformation of the entire vertical roll device, etc. When the vertical roll jump amount △S is calculated, the vertical roll position calculation device 6 subtracts the jump amount △S from the required strip width pattern B _SO before rolling, and calculates the vertical roll as B _C =B _SO −△S. Roll position B _C is calculated. At the timing when the relevant part of the metal material 1 whose width before rolling is stored in the sheet width pattern determination storage device 5 is rolled by the vertical rolls 2 of the rough rolling mill, the corresponding vertical roll position calculated by the method described above is calculated. Using B _C , the vertical roll position is controlled by the vertical roll position control device 7, and the target plate width B _S is obtained over the entire length of the metal material 1.

[Problem that the invention seeks to solve]

Although the conventional board width control device is configured as described above, it has the following problems.

In other words, the phenomena related to sheet width deformation that must be taken into account when setting the vertical roll position are the vertical roll jump amount △S due to the elastic deformation of the vertical roll device, and the width expansion amount △BDH due to the horizontal roll. be. According to the above symbols, ΔBDH is expressed as the difference between the target strip width B _S and the required strip width B _SO before rolling, that is, ΔBDH=B _S −B _SO . This △BDH is further calculated by the simple width expansion amount △BH of the metal material with the horizontal rolls and the raised deformation of the thickness that occurs at the edge in the width direction of the sheet during width reduction with the vertical rolls, that is, the dogbone. It can be considered separately as the dog bone width return amount ΔBD that returns in the width direction during rolling. Among these, the simple width expansion amount ΔBH is mainly determined by the plate thickness and rolling reduction rate with the horizontal rolls. On the other hand, the amount of dogbone width return is mainly determined by the amount of width reduction by the vertical rolls, and is generally larger than the amount of simple width expansion. In other words, the target plate width on the exit side of the horizontal roll
In order to obtain B _S , the amount of width change in horizontal roll △BDH
In consideration of this, when determining the required width _BSO before rolling, the amount of width reduction with the vertical rolls must be determined. In other words, it is not possible to correctly determine the target strip width before rolling independently of the vertical roll position B _C as in the conventional method.

In addition, one of the main factors in sheet width accuracy that generally impedes yield improvement is that the margin width cannot be reduced due to sheet width fluctuations within the product sheet. In this sense, (tip) as an absolute value
Plate width accuracy is a matter of the setting function of the rough rolling mill.
It is important to obtain a uniform plate width over the entire longitudinal length of the metal material by controlling the plate width.

This invention was made to solve the above problems, and it is difficult to accurately set the vertical roll position in order to obtain a metal material with a uniform width over the entire length at the exit side of the horizontal roll of the rolling mill. The purpose of this study is to obtain a board width control device that uses the following methods.

[Means for solving problems]

The strip width control device according to the present invention is provided with a strip width meter on the entrance side of the vertical rolls, and uses the influence sensitivity derived from the relational expression representing the deformation of the strip width at the vertical rolls and horizontal rolls of the rolling mill to control the width of the strip. When there is a deviation between the actual measurement value measured by the width meter and the actual measurement value of the strip width at the tip, the amount of vertical roll position correction is derived based on the influence sensitivity, and the width of the strip is uniform at the exit side of the horizontal roll. It was designed to obtain

In addition to the above, another invention of the present invention is to provide a thermometer on the entrance side of the vertical roll, and to measure the sensitivity of the influence of temperature fluctuations of the metal material measured by the thermometer on the sheet width on the exit side of the horizontal roll. The vertical roll position correction amount is derived by taking this into account.

[Effect]

The influence sensitivity in this invention was derived from a relational expression that also takes into account the change in the width expansion of the horizontal roll due to the change in the width reduction of the vertical roll. When the vertical roll position is corrected, the vertical roll position is corrected by taking into account the change in the width expansion amount of the horizontal roll, and it is possible to obtain a uniform sheet width on the horizontal roll exit side. .

In addition to the above, another invention of the present invention is to correct the vertical roll position by taking into consideration the sensitivity to the influence of temperature fluctuations of the metal material, so that a more uniform sheet width can be obtained on the exit side of the horizontal roll. Can be done.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a metal material to be rolled;
2 is a vertical roll of the rolling mill, 3 is a horizontal roll of the rolling mill, 4 is a strip width meter installed upstream of the vertical roll 2, and 5a is a memory for the actual measurement value of the strip width on the entrance side of the vertical roll by this strip width meter 4. 6 is a vertical roll position calculation device that derives the vertical roll correction position, 7 is a vertical roll position control device, 8 is a setting device that calculates various set values and predicted values, 14 is the vertical roll 2 entrance plate This is a device that calculates the influence sensitivity to changes in the width of the horizontal roll outlet plate due to changes in width and changes in the vertical roll position.

The plate thickness H for the metal material 1, the predicted plate width B _O on the entrance side of the vertical rolls, the reduction ratio r in horizontal rolling, the target plate width B _S on the exit side of the horizontal rolls, the predicted rolling temperature value, etc. are given by the setting device 8. It will be done.

Next, the influence sensitivity calculation device 14 calculates the influence sensitivity G _W on the sheet width on the outlet side of the horizontal roll 3 due to a change in the sheet width on the input side of the vertical roll 2, and the influence sensitivity on the sheet width on the outlet side of the horizontal roll 3 due to a change in the position of the vertical roll 2. Calculate G _E as follows. Horizontal roll 3 outlet plate width W _put
is W _put = f (W _io , E, H, r, t, ...)
...(1) It is expressed as. Here, W _put : Horizontal roll outlet plate width W _io : Vertical roll inlet plate width E : Vertical roll position H : Horizontal roll inlet plate width r : Horizontal roll rolling reduction ratio t : Horizontal roll rolling temperature.

To give a specific example, W _put = W _io + {a ₁ E + a ₂ E ² + a ₃ tE + a ₄ W _io / HE + a ₅ (H-h) + a ₆ t (H-h) + a ₇ W _io (H -h)} ...(1') However, h: Horizontal roll application thickness (relationship: r=H-h/H) _a1 to _a7 : Coefficients determined using actual data through statistical multivariate analysis. , commonly known.

From equation (1), when the vertical roll 2 entrance board width W _io changes by △W _io and the vertical roll 2 position changes by △E, the change in the horizontal roll 3 exit board width △W _put is △W _put ≒ ∂f/ ∂W _io △W _io + ∂f/∂E△E ...(3).

The partial differential coefficient ∂f/∂W _io in equation (3) represents the amount of change in the width of the horizontal roll 3 outlet side that occurs when the input side plate width of the vertical roll 2 changes by a unit amount, and the partial differential coefficient ∂f/∂E Vertical roll 2 Horizontal roll 3 that occurs when the position changes by a unit amount
Indicates the amount of change in board width on the exit side. That is, the former is the sensitivity G _W of the influence of the vertical roll 2 inlet side sheet width change on the horizontal roll 3 side sheet width change, and the latter is the influence sensitivity G W of the vertical roll 2 position change on the horizontal roll 3 exit side sheet width change. It is _E. Then, becomes.

The above calculations are derived by the influence sensitivity calculation device 14 before the metal material 1 reaches the board width meter 4 on the input side of the vertical roll 2.

When the metal material 1 reaches the sheet width meter 4 on the input side of the vertical roll 2, the actual sheet width value B of the metal material 1 is stored in the sheet width storage device 5a. Using the actually measured B and the above-mentioned influence sensitivities _GW and _GE , the vertical roll position calculation device 6 calculates the vertical roll correction position as follows.

That is, it is considered that the vertical roll position opening degree is generally set by the setting function of the rough rolling mill so that the tip end portion of the metal material 1 obtains the target sheet width on the exit side of the horizontal roll 3. Therefore, the actual value of the plate width at the tip of the metal material 1 on the entry side of the vertical roll 2 is used as the standard plate width.
B ^* , and by performing control by taking the deviation from this standard plate width, the metal material 1 with a uniform plate width on the exit side of the horizontal roll 3 is obtained. Now, when the actual measurement value B of the board width at the entrance side of the vertical roll 2 at a certain part of the metal material 1 has a deviation of △B=B-B ^* from the reference board width B ^* at the tip, the vertical roll position If you move △E from the initial setting value E _O , on the horizontal roll exit side,
The difference between that part and the tip is △W _put =G _F・△B+G _E・△E ……(5).

Therefore, in order to make the sheet width at the exit side of the horizontal roll 3 equal to the tip end, in other words, to make △W _put = 0, set the left side of equation (5) to 0 and set the vertical roll position as △E=-G _W ／G _E・△B ……(6) only needs to be corrected. In other words, if there is a board width deviation of △B from the standard board width on the input side of the vertical roll 2,
The vertical roll correction position E ₁ is set as E ₁ =E ₀ −G _W /G _E・△B (7).

The vertical roll position control device 7 outputs the calculated vertical roll correction position E ₁ as described above in accordance with the timing when the part whose width of the plate is actually measured on the input side of the vertical roll position is rolled by the vertical rolls 2. By controlling the position of the vertical rolls, a uniform sheet width is obtained over the entire length of the metal material 1 on the exit side of the horizontal rolls.

In addition, in the above example, only the plate width variation on the input side of the vertical roll 2 was taken up as a factor of the output plate width variation, and what was actually measured was shown, but as shown in FIG. Control may also be performed by paying attention to temperature fluctuations and actually measuring the temperature at the entrance side of the vertical roll 2. In this case, considering the temperature fluctuation in equation (3), △W _put ≒∂f／∂W _io △W _io +∂f／∂E・△E+∂f／∂t△t ……(3′ ). The partial differential coefficient ∂f/∂t represents the amount of change in the sheet width on the exit side of the horizontal roll 3 that occurs when the rolling temperature on the horizontal roll 3 changes by a unit amount.

In other words, the sensitivity of the rolling temperature change to the horizontal roll outlet width change G _T can be calculated as G _T = ∂/∂tf (W _O , E _O , H, r, t _O ) ……(4′) .

In addition, the temperature of the metal material 1 at the entrance side of the vertical roll 2 is actually measured by the thermometer 15, and the temperature change from the actual measurement position to the horizontal roll is taken into consideration, and the temperature is stored in the temperature storage device 5b as the temperature at the horizontal roll. .

Plate width deviation from standard plate width at vertical roll entry side △B
When there is a deviation △t between the rolling temperature t on the horizontal roll 3 and the actual measured temperature t ^* at the tip of the metal material 1, if the vertical roll position is moved △E from the initial setting value,
According to formulas (3') and (4'), on the exit side of horizontal roll 3, △W _put =G _W・△B+G _T・△t+G _E・△E
...(5') deviation in board width from the board tip occurs.

Therefore, in order to set △W _put = 0, it is only necessary to correct the vertical roll position by △E = -G _W · △B + G _T · △t ₀ /G _E . . . (6'). In other words, vertical roll correction amount
Let E ₁ be E ₁ =E ₀ −G _W・△B+G _T・△t ₀ /G _E ……(7′).

Note that even in the above example using temperature information, actual measurements and
Needless to say, calculations and controls are performed so that the memorized temperature and sheet width correspond to the part of the metal material whose width is to be reduced by the vertical rolls.

〔Effect of the invention〕

As described above, according to the present invention, from the relational expression expressing the deformation of the sheet width, the influence sensitivity of sheet width fluctuations based on the sheet width at the tip of the metal material on the input side of the vertical rolls on the sheet width at the exit side of the horizontal rolls is determined. Derive the amount of correction of the vertical roll position using G _W and the influence sensitivity G _E on the sheet width at the exit side of the horizontal roll when the vertical roll position is changed,
Since the vertical roll position is controlled, there is an effect that the actual plate width at the tip of the metal material can be used as the reference plate width to control the target plate width with high precision.

According to another invention of this invention, the influence sensitivity
In addition to GW and GE, the effect sensitivity GT on the strip width at the exit side of the horizontal roll when the rolling temperature changes by a unit amount
Since the position of the vertical rolls is controlled in consideration of the above factors, the sheet width of the metal material can be maintained at the target sheet width even when the rolling temperature fluctuates, and there is an effect that more accurate control can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a board width control device according to an embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional board width control device. FIG. In the figure, 1 is a metal material, 2 is a vertical roll, and 3
is a horizontal roll, 4 is a board width meter, 5a is a board width storage device, 5b is a temperature storage device, 6 is a vertical roll position calculation device, 7 is a vertical roll position control device, 8 is a setting device,
14 is an influence sensitivity calculation device, and 15 is a thermometer.
In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a device for controlling the width of a metal material rolled by a rolling mill having a horizontal roll and a vertical roll provided immediately before the horizontal roll, a width gauge is provided on the entrance side of the vertical roll, The influence sensitivity GW of the change in sheet width based on the tip sheet width of the metal material measured by the sheet width meter on the sheet width at the exit side of the horizontal roll, and the influence sensitivity GW on the sheet width at the exit side of the horizontal roll when the vertical roll position is changed. A board width control device characterized in that an influence sensitivity GE that affects the board width is derived in advance, and a vertical roll position is corrected based on the measured value of the board width meter and the influence sensitivities GW and GE. 2. In a device that controls the plate width of a metal material rolled by a rolling mill that has a horizontal roll and a vertical roll installed immediately before the horizontal roll, a plate width meter and a thermometer are installed on the entrance side of the vertical roll, and the plate width is Influence sensitivity GW of how changes in sheet width based on the tip sheet width of the metal material actually measured by a meter will affect the sheet width at the exit side of the horizontal roll, and the influence sensitivity GW on the sheet width at the exit side of the horizontal roll when the vertical roll position is changed. The influence sensitivity GE that influences and the influence sensitivity GT that influences the strip width at the exit side of the horizontal roll when the temperature of the metal material measured by the above thermometer changes by a unit amount are derived in advance, and the measured value of the above strip width meter and A sheet width control device characterized in that the vertical roll position is corrected using the above-mentioned influence sensitivities GW, GE, and GT.