JPS6238041B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a plate thickness calculation device for the final pass of tentering rolling in thick plate rolling, and particularly to a plate thickness calculation device for a thick plate rolled material suitable for obtaining a predetermined product width. This invention relates to a thickness calculation device.

[Conventional technology]

Generally, the rolling process of thick plate rolled material is shown in Fig. 1A,
It is classified into three stages shown in B and C. Figure 1A
The step is forming rolling for adjusting the shape of the rolled material 1, which is the material of the thick plate, and the rolling direction R is the longitudinal direction of the product. When this forming rolling is completed, the rolled material 1 is turned 90 degrees and rolled in the width direction in the tentering rolling shown in FIG. ₂
(See Figure 2)). In this case, the width shape of the rolled material generally changes irregularly in the longitudinal direction of the rolled material (the longitudinal direction of this rolling) as shown in FIG. The target plate thickness T ₂ is calculated based on the target average plate width Bm ₂ calculated to obtain the required product width b as follows.
Tenter rolling is performed with the goal of At the end of tentering rolling, the rolled material 1 is turned again by 90 degrees and
In the finish rolling shown in Figure C, the steel sheet is rolled in the longitudinal direction to a thickness required as a product.

Here, the average plate width of the rolled material Bm ₂ and the thickness of the rolled material T ₂ at the end of tentering rolling, and its length L ₂ are the width of the rolled material as the rolled material B ₀ its thickness T ₀
If its length is L ₀ , the width of the rolled material at the end of forming rolling is B ₁ , its thickness is T ₁ and its length is L ₁ , then T ₂ = B ₀ ×T ₀ /Bm ₂ × It is calculated by either L ₀ /L ₂ (1) or T ₂ =B ₁ ×T ₁ /Bm ₂ ×L ₁ /L ₂ (2). Comparing equations (1) and (2), we can see that the thickness T ₀ of the rolled material at the time of the raw material fluctuates considerably due to unevenness caused by surface care, whereas the thickness of the rolled material at the end of forming rolling T ₁
can be determined accurately from the roll gap at the end of forming and rolling. Therefore, it is recognized that it is more reliable to calculate the thickness of the rolled material _T2 at the end of tentering using equation (2). ing.

Note that the width expansion during rolling (stretching of the rolled material in the axial direction of the rolling rolls) is negligible, so L ₂ ≒ L ₁ , and equation (2) is as follows: T ₂ = B ₁ ×T ₁ /Bm ₂ (2)′, which is the target thickness of the plate in the final pass of tentering rolling.
_T2 is required. By performing rolling based on this target plate thickness T ₂ , an actual average plate width close to the target average plate width Bm ₂ is obtained. Furthermore, for the same reason, B ₁ ≒ B ₀ , so B ₀ can be used as is in place of B ₁ in equation (2)'.

In addition, the average strip width Bm ₂ of the rolled material at the end of tentering rolling is the margin necessary to draw out the product width b and the product width b, as shown in Fig. 2, and is determined by the equipment. If the cutting allowance is △b, and c is the average widthwise amount of the unnecessary part (hatched area) to cut out the product, and c is the amount of defective shape obtained by dividing the area of the shaded area by the product length, then Bm ₂ =b+2(△b+c) (3)

[Problems with conventional technology]

By the way, when calculating the average plate width Bm ₂ of rolled material at the end of tentering rolling in the conventional rolling process of rolled material, the amount of shape defects c varies widely depending on the heating conditions of the rolled material, rolling conditions, etc. It is very difficult to accurately predict the amount of defective shape c before rolling, and there is no way to detect the amount of defective shape c during rolling. value is adopted. Therefore, in the conventional rolling work of rolled material, the average plate width of the rolled material Bm ₂ (formula (3)) and the thickness of the rolled material
There are problems in that it is difficult to appropriately calculate T ₂ (formula (2)′), the product yield is poor, and the product may not be able to be collected.

The present invention has been made in view of the above-mentioned conventional problems.The present invention actually measures the shape defect amount C, which varies depending on the rolling conditions, during rolling, and calculates the optimum target average sheet width _Bm2 from this. Equation (3)), and finally the optimum target plate thickness T ₂ is calculated (Equation (2)′), and the target average plate width Bm ₂ is calculated by subsequent rolling based on this target plate thickness T ₂ .
It is an object of the present invention to provide a plate thickness calculating device for the final pass of tentering rolling in thick plate rolling, which can obtain a closer actual average plate width, furthermore obtain a predetermined product width b, and improve product yield. purpose.

[Means for solving problems]

The plate thickness calculating device for the final pass of tentering rolling in thick plate rolling according to the present invention aims to more accurately obtain the value of the shape defect amount C by applying a beam (laser beam) to the rolled material. In other words, there is a beam projection device that projects a large number of beams onto the rolled material before the final pass of tentering rolling, a rolled material speed detection device that detects the speed of the rolled material at the time of beam projection, and a beam shielding system for each beam position. an integral circuit that calculates the width of the rolled material at each beam position by integrating the speed of the rolled material over time; a circuit that determines the shape of the rolled material from the width of the rolled material calculated by the integration circuit; and a circuit that determines the shape of the rolled material from this shape. The circuit for determining the amount of defects c, the product width b, and the amount of shape defects c determined from the above (see formula (3)) Target average strip width Bm ₂ at the end of tentering rolling and rolled material strip width B ₁ after finishing forming rolling and a calculation circuit that calculates the target plate thickness T ₂ of the final pass of tentering rolling based on the plate thickness T ₁ and the plate thickness T 1 (see formula (2)′).

[Effect]

The shape defect amount C can be more accurate than the predicted value using conventional statistical methods. Therefore, a more suitable target average plate width Bm ₂ can be calculated, and therefore a more suitable target plate thickness T ₂ can be calculated. As a result, the final pass of tentering rolling is performed with this target plate thickness T ₂ as the target, and it is possible to obtain an actual average plate width that is closer to the target average plate width Bm ₂ and obtain a predetermined product width b. .

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing a beam projection device 10 constituting a plate thickness calculating device for the final pass of tentering rolling in thick plate rolling according to the present invention, and a pilot generator 20 as a rolled material speed detecting device. . Rolled material 1 rolled by rolling roll 2
is carried into the beam projection device 10 by the roller table 3 one pass before the final pass of tentering rolling. The beam projection device 10 includes a large number of laser transmitters 1 arranged above and below a roller table 3 and facing each other.
1 and a laser receiver 12, and a large number of laser beams 13 are scanned at high speed in the line width direction. When the rolled material 1 passes through this beam projection device 10, the rolled material 1 is exposed to the laser beam 1.
3, and the time during which the laser beam 13 is blocked differs depending on the position of each laser beam 13 according to the change in the width shape of the rolled material 1. On the other hand, the laser beam 13 is controlled by a pilot generator 20 attached to the end of the roller table 3 that is conveying the rolled material 1.
The speed of the rolled material 1 while it is being projected is detected. By integrating this rolling material speed for each projection position of each laser beam 13 by the time from the time when the laser beam 13 is shielded to the time when the shielding is finished, the projection position of each laser beam 13 is determined. The plate width of the rolled material 1 at is measured.

FIG. 4 shows the speed v(t) of such a rolled material 1.
FIG. 3 is an explanatory diagram showing the relationship between and shielding time, in which the speed v(t) of the rolled material 1 detected by the pilot generator 20 changes depending on the time t. The laser beam 13 is scanned at high speed, and t ₁ to tn indicate each scan time.
If the scan bit is △t, then △t=t ₂ −t ₁ =t ₃ −t ₂ =tn−tn− ₁ (4), and for example, the projection position of the laser beam 13 is
If it is shielded from t ₁ to tn in (1), the plate width w ₁ of the rolled material 1 at the projection position (1) is Therefore, the width of the rolled material 1 at the projection position (K) of the laser beam 13 is generally It is represented by.

That is, based on equation (6), each laser beam 1
For each projection position of 3, the width of the rolled material 1 at each projection position one pass before the final pass of tentering rolling is calculated by an integrating circuit that integrates the speed of the rolled material by the time when the laser beam 13 is blocked. can be calculated.

Next, based on the rolled material plate width calculated by the integral circuit, the arithmetic circuit calculates the shape of the rolled material, the amount of defective shape, and the thickness of the rolled material in the final pass of tentering rolling. That is, the width shape of the rolled material 1 that was originally expected was Bm ₂ = b + 2 (△b + c) (7) as shown by the dashed line in Fig. 5A, but If the width of the rolled material 1 at the projection position of each laser beam 13 measured by the integrating circuit is integrated and shown as shown by the solid line in FIG. 5A, in this case, Not only is it not possible to secure a predetermined cutting allowance Δb, but it is also impossible to sample a predetermined product width b.

Therefore, in such a case, the actual shape defect amount c' given to the rolled material 1 is calculated by the plate width w ₁ of the rolled material 1 at each projection position of each laser beam 13 calculated by the integrating circuit. ~wn to calculate the optimal target average plate Bm ₂ ' to obtain the required product width of the rolled material 1. In other words, the minimum value among the actual plate widths w ₁ to wn of the rolled material 1 is w
min, the beam pitch of the laser beam 13 is △x, and the product length is l, then the shape defect amount c' in this case is: In this case, the target average plate width of the rolled material is
Bm ₂ ′ becomes Bm ₂ ′=b+2(△b+c′) (9). Therefore, the target thickness of the rolled material T ₂ ′ in the final pass of tentering rolling is calculated as T ₂ ′=B ₁ ×T ₁ /Bm ₂ ′ (10), and tentering is performed based on this target thickness. If the final pass of rolling is performed, a rolled material with a predetermined product width b can be obtained.

FIG. 6 is a circuit diagram showing an embodiment of the plate thickness calculation device for the final pass of tentering rolling in thick plate rolling according to the present invention, and shows the shielding time of each laser beam 13 in the beam projection device 10 described above. It is equipped with a shielding signal generator 30 that transmits the shielding signal to the integrating circuit 40, and a pilot generator 20 that detects the speed of the rolled material during beam projection and transmits it to the integrating circuit 40. The width of the rolled material plate at each projection position of the beam is calculated using the following as input. The output of the integrating circuit 40 is transmitted to a shape calculation circuit 50, and the shape calculation circuit 50 determines the actual width shape of the rolled material. The output of the shape defect calculation circuit 50 is transmitted to the shape defect amount calculation circuit 60, which calculates the actual shape defect amount of the rolled material, and the output of the shape defect amount calculation circuit 60 is further transmitted to the thickness calculation circuit 70 for width adjustment. The average strip width at the end of rolling is calculated, and the thickness of the rolled material in the final pass of tentering rolling is calculated based on this average strip width and the rolled material strip width and thickness at the end of the forming pass. There is.

The above calculation results are transmitted to the rolling mill operator or the rolling mill reduction control computer, and are fed forward to the final pass of tentering rolling, which is the final pass of tentering that was originally determined to obtain the required product width. By adjusting the thickness of the rolled material during rolling, it is possible to adjust the rolling operation according to the rolling conditions during rolling, and to appropriately obtain a product having a predetermined width.

In the above embodiment, the beam emitted from the beam projection device is a laser beam, so it can be used even in a steam-filled atmosphere around the rolling mill due to its good properties such as non-divergence and high transparency. , it is possible to accurately detect the shielding time by the rolled material. However, the beam emitted by the beam projection device constituting the present invention is not limited to a laser beam, and white light or monochromatic light that is difficult to attenuate in the atmosphere around the rolling mill may be used.

As described above, the plate thickness calculation device for the final pass of tentering rolling in thick plate rolling according to the present invention includes a beam projection device that projects a large number of beams onto the rolled material before the final pass of tentering rolling, and a rolled material speed detection device that detects the rolled material speed at each beam position, an integral circuit that integrates the rolled material speed at each beam position by the time when the beam is blocked, and calculates the rolled material plate width at each beam position; A circuit that determines the shape of the rolled material from the width of the rolled material sheet calculated by the circuit, a circuit that calculates the amount of shape defect from this shape, and a circuit that determines the product width and the average sheet width at the end of tentering rolling determined from the amount of shape defects and forming. Since it has a calculation circuit that calculates the plate thickness of the final pass of tentering rolling based on the width and thickness of the rolled material after rolling, it is possible to reduce the amount of shape defects in the rolled material that vary depending on the rolling conditions. This method has the advantage of being able to accurately measure during rolling and obtain a predetermined product sheet width through subsequent rolling, thereby improving product yield.

[Brief explanation of the drawing]

1A to 1C are perspective views showing the rolling process of a general rolled material, FIG. 2 is a plan view showing the planar shape of a general rolled material, and FIG. 3 is the final pass of tentering rolling in thick plate rolling according to the present invention. FIG. 4 is a diagram showing the relationship between rolling material speed and beam shielding time; FIGS. 5A and B 6 is a plan view showing the planar shape of a rolled material, and FIG. 6 is a circuit diagram showing an embodiment of a width control device for a rolled material according to the present invention. 10...Beam projection device, 20...Pilot generator, 30...Shielding signal generator, 40
...Integrator circuit, 50...Shape calculation circuit, 60...
Shape defect amount calculation circuit, 70...Thickness calculation circuit.

Claims (1)

[Claims] 1. A beam projection device that projects multiple beams onto the rolled material before the final pass of tentering rolling, a rolled material speed detection device that detects the speed of the rolled material during beam projection, and a beam shielding system for each beam position. An integral circuit that calculates the width of the rolled material at each beam position by integrating the speed of the rolled material over time, a circuit that determines the shape of the rolled material from the width of the rolled material calculated by the integration circuit, and a circuit that determines the shape of the rolled material from this shape. The target plate thickness for the final pass of tentering rolling based on the circuit for calculating the quantity, the target average plate width at the end of tentering rolling determined from the product width and the amount of shape defects, and the rolled material plate width and plate thickness after finishing forming rolling. An arithmetic circuit for calculating the plate thickness for a final pass of tentering rolling in thick plate rolling.