JPS6152916A - Camber controlling method of rolling material in thick plate rolling - Google Patents

Abstract

PURPOSE:To promote the justification of the bend of a plate material by calculating the prescribed wedge quantity from the meandering quantity of a rolling material and by controlling a roll gap quantity based on the wedge quantity thereof. CONSTITUTION:The revision of the nonsymmetry due to the meandering of a rolling material is calculated by a calculator F26 and the degree rho*' in the relief or thickening of a camber is found. The wedge quantity is found by the calculator F17 finding the necessary wedge quantity hdf*'' on the outlet side and further the target wedge quantity hdf*' before revision is found by a proportion gain calculator K18. The target wedge quantity hdf* is found with performing the wedge quantity revision of a calculators F39 and F411 from the value thereof. Thereafter the roll opening difference Sdf* is determined by a calculator F410 and the rolling of an oil pressure rolling reduction device 12 and rolling mill 13 is performed and the product having the actual wedge (hdf) is made. The bend of rolling plate material can be controlled within the minute range centering around the target value with said method.

Description

Detailed Description of the Invention (Industrial Application IP) The present invention corrects the camber of rolled material during thick plate rolling.
This invention relates to a controlled rolling method.

(Prior art) During rolling of steel plates, etc., due to differences in hardness on the left and right sides of the material to be rolled, differences in rigidity (mill constant) on the left and right sides of the rolling mill, and other factors, the material to be rolled may change in the rolling mill. There are problems in that a meandering phenomenon occurs in which the biting position shifts in the width direction, and a phenomenon in which the rolled material curves in the width direction, that is, camber occurs.

If this camber is large, the material to be rolled will damage the rolling rolls and guides, and in severe cases may even cause damage, resulting in great damage in terms of time and material.

Also, even if the camber is small, as shown in Figure 2,
At the curved portion of the rolled material 1, the plate 2 cannot be of a predetermined size, and the yield of the product decreases. Therefore, it is necessary to measure the center line profile of the rolled material 1 and quickly control the rolling according to the amount of camber. By the way, conventional camper control is performed by manipulating the difference in left and right roll opening (leveling operation) in order to obtain a plate wedge according to the amount of camber. The leveling operation is performed according to the amount of meandering (off-center) that occurs during rolling, using the obtained target value of the exit side wedge amount as a control variable.

(Problem to be Solved) However, in the conventional camber control method for rolled material, there is a true crown on the work roll. Due to roll crowns such as wear crowns and heat crowns, and roll deflection, when meandering occurs, the thickness distribution in the width direction becomes asymmetrical, and the relationship between wedge and camber changes. Even if the wedge amount is controlled to the amount set before rolling, the predetermined camber cannot be corrected, and there is a problem that uncorrected camber remains.

The present invention eliminates the drawbacks and problems of the prior art.

The purpose of this invention is to provide a method for controlling camber of rolled material in thick plate rolling, which can improve
The above object can be achieved by providing a method for controlling camber of a rolled material during thick plate rolling as described in the claims. That is, the present invention corrects the camber by measuring the amount of camber of a rolled material that occurs during rolling in thick plate rolling, and controlling the roll gap difference between the driving side and the operating side of the next pass according to the camber amount. When doing so, the meandering noise of the rolled material is detected, a predetermined wedge amount is calculated from the meandering mark and a function representing the nonlinear relationship between the rolled material wedge and camber caused by the asymmetry of the rolled sheet crown, and the wedge amount is The present invention relates to a method for controlling the diameter of a rolled material in thick plate rolling, which controls the roll gap difference based on the amount.

The method for controlling the camber of a rolled material in thick plate rolling according to the present invention will be described below.

The relationship between the work rolls and the rolled material is shown in FIGS. 3, 4, 5, and 6. FIG. 3 shows the deformation of the rolled material 5 when there is no meandering in the rolled material, and the deformation of the work roll 3.
The deflection shape of 4 is shown, and the flexure shape of 4 is shown.
By rolling down the rolled material 5, a wedge and a plate crown are formed. The amount of work roll 3.4 is symmetrical and wedge (the shape is indicated by the dashed line in the figure).
Based on , the plate crown will be symmetrical on the left and right sides of the plate.

Assuming that all the difference in elongation in the width direction due to the wedge results in bending and no internal stress is generated, the internal stress caused by the difference in elongation in the width direction due to the plate crown will be symmetrical in the width direction and balanced between the left and right sides.

In Figure 4, work roll 3.4 has a crown, but
Similarly to the figure, the rolled material 5 shows the case where there is no meandering. In this case as well, the plate crown is symmetrical with respect to the wedge, and if there is no meandering in the rolled material, the bending of the plate can be corrected only by changing the wedge amount.

On the other hand, a case where the rolled material has meandering and no roll crown is shown in FIG. 5, while a case with a roll crown is shown in FIG. In FIGS. 5 and 6, the work rolls 3 and 4 and the rolled material 5 are illustrated in the same way as in FIGS. 3 and 4. As is clear from Figures 5 and 6, in both cases, the amount of plate crown based on the wedge is asymmetrical, and the internal stress distribution of the plate is also asymmetrical, so the moment within the plate due to this internal stress is balanced. This causes the board to bend, and the board cannot simply correct the bend using wedges alone. In other words, it is necessary to set a target value for the wedge amount that takes into account the influence of the asymmetry of the plate crown.

(Means for Solving the Problems) The camber control method of a rolled material in thick plate rolling according to the present invention provides a camber correction method based on the rolling characteristics as described above.

Next, the method of the present invention will be explained in detail with reference to FIG. In the figure, the camper curvature to be corrected is 271 from the side plate wedge Hdf to the required exit side wedge ffi hdf*/
An arithmetic unit Fl 7 is provided for calculating '.

The required exit side wedge amount h4f- is a function of the plate thickness S, the input side plate wedge Hd1, and the camber curvature to be corrected ρ'' = h(b, Hdf, ρs'...
).

In addition, a function calculator Fz 6 is provided which expresses the degree of relaxation or increase in camber due to the asymmetry of the plate crown caused by meandering of the rolled material.
The apparent target camber curvature door', which takes into account the influence of the actual meandering δ, on the plate thickness and rolling pressure (lo+
P”' = f 2 (b * (
Lo l CW F61...).

Next, change the output side wedge amount hdf appetizer to the target wedge before correction.
18 is provided in an amplifier that provides a proportional gain of "lhaf".

Next, a calculator F39 is provided to calculate the wedge amount due to the meandering δ, and the correction amount Δhdf of the wedge amount due to the meandering is determined by the plate width, rolling pressure (lo + work roll crown Cw
, as a function of meandering δ, △hdf ” = f31 b + qop Cw, δ・
...).

Next, the target roll opening difference Sdf from the target
A calculation unit F410 is provided to calculate the target low b? be done.

Furthermore, the wedge amount is corrected from the actual opening difference Sdf △hdf2”
A calculator F511 is provided to perform the wedge correction amount △
hdf2'' is expressed as Δhdf2''=f5(b, qOlSdf...) as a function of plate width, rolling pressure qo+actual opening difference Sdf.

According to the conventional camber control method of rolled material in thick plate rolling, the amount of camber to be corrected is carried out by the F17 computing unit step which calculates the necessary exit wedge from the entrance plate wedge, and the camber control method is performed by the F17 calculator step, which calculates the camber amount to be corrected and the necessary exit wedge from the entrance plate wedge. No consideration was given to the asymmetry of the plate crown.

According to the method of the present invention, the correction of asymmetry caused by meandering of the rolled material is calculated by F26, the degree of camber relaxation or increase ρ is calculated, and then the calculation unit Fl is used to calculate the required exit side wedge amount hdf+W. The wedge amount is determined in step 7, and the target wedge amount hdf"' before correction is determined using the proportional gain calculator. Based on the meandering calculated in step 9, the wedge correction value Δhdf1+ and
Subtract the wedge amount correction value △hdf2'' based on the actual roll opening difference calculated in F411, and set the target wedge amount as hd.
f is calculated, and the target roll opening difference S is determined by the calculator F410.
After determining the d-edge, rolling is performed using the hydraulic reduction 12 and the rolling mill 13 to produce a product with an actual wedge hdf.

Next, the present invention will be explained in detail with reference to examples.

EXAMPLE FIG. 7 shows the results of an experiment using a 1/10 model mill to determine the relational expression between wedge and camber due to meandering. The figure shows the case where the board width is 400 m, and the off-center is constant ↓ A guide was installed on the entry side of the sea urchin.

Comparing the plate thickness distributions when off-center δ = between 0 and 100, Figure 8 (a) shows the case where δ = Q tnm, and Figure 8 ('b) shows the case where δ = 100. δ=Q
In the case of tHL, bilaterally symmetrical plate 2-kun occurred, whereas in the case of δ = 100 M, it became bilaterally asymmetrical. Even though the wedge amount is equal to o and os w in both cases, the amount of bending of the plate is δ=Q as shown in Figure 7. Various plate widths based on experimental values using a model mill,
The functions obtained for the rolling pressure, roll diameter, meandering amount, etc. are incorporated into the calculator F2, and depending on the presence or absence of coefficients by the calculator F2,
The results confirmed using a similar model mill are shown in FIG. Despite setting the target camber curvature P'' such that the exit side camber curvature is 0 as an experimental condition,
When the target wedge amount hdf was calculated without the coefficient by the calculator F2, all the curves 9 in the same direction were generated under the condition with off-center, but when the target wedge amount hdf was calculated by the calculator F2 with the coefficient, the target wedge amount hdf4) When , the curvature after correction varied around 0, and the absolute value was smaller than that without the coefficient by the calculator F2, confirming the effectiveness of the present invention. In the case of this embodiment, the camber is relaxed due to the asymmetry of the plate crown, and the IcU camber will be excessively corrected if there is no coefficient by the calculator F2.

(Effects of the Invention) As explained above, in rolling a thick plate, the amount of meandering on the rolling side is detected, and the nonlinear relationship between the meandering amount and the wedge of the rolled material and the camber, which is caused by the left-right asymmetry of the crown of the rolled plate, is determined. It has become clear that by calculating a predetermined wedge amount from the function expressed and controlling the roll gap based on the wedge amount, the corrected bending can be controlled within a minute range around the target value, and the effect is extremely big.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the camber control logic of the present invention, Fig. 2 is a plan view illustrating the inconvenience caused when camber occurs, and Figs. 3 and 4 are deformation of the roll when there is no meandering. State explanatory diagram, Fig. 5. Figure 6 is an explanatory diagram of the roll deformation state when meandering occurs, Figure 7 is the plate profile in the model mill, Figure 8 is the plate thickness distribution in the model mill, and Figure 9 is a diagram showing the results of confirmation experiments using the model mill. It is. l...Rolled material (plane), 2...Product shape (plane),
3... Work roll, 4... Work roll, 5...
・Rolled material (cross section), 6... Computing unit F2.7... Computing unit F1.8... Proportional gain Kl, 9... Computing unit F3
．． 10...Arithmetic unit F4.11...Arithmetic unit F5.12
... Hydraulic rolling device, 13... Rolling machine.

Claims (1)

[Claims] 1. In thick plate rolling, by measuring the amount of camber of the rolled material generated during rolling and controlling the roll gap difference between the driving side and the operating side of the next pass according to the camber amount. Therefore, when correcting the camber: The amount of meandering of the rolled material is detected, and a predetermined amount of wedge is determined from the amount of meandering and a function representing the nonlinear relationship between the wedge of the rolled material and the camber, which occurs due to the left-right asymmetry of the crown of the rolled sheet. A method for controlling the camber of a rolled material in thick plate rolling, the method comprising: calculating the wedge amount, and controlling the roll gap difference based on the wedge amount.