JPH09206813A - Intermediate roll shifting amount setting in hot rolling finish mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax a rapid intermediate roll shifting and to stabilize passing of a plate by deciding the roll shifting amount in consideration of the condition on a stock concerned to be set and a succeeding stock and a next succeeding stock, etc., based on the table value of an intermediate roll shifting amount previously classified with the kind of steel and the dimension. SOLUTION: The rolling stock P is rolled with a finish stand 1. A rolling stock P of order (j) in a stand (i) is designated as the stock concerned, and the intermediate roll shifting amount SIij is calculated with a formula. The shifting amount table values SITBij , SITBij+1 and SITBij+2 of intermediate rolls of the stock concerned, the succeeding stock of order (j)+1 and the next succeeding stock of order (j)+2 in the stand (i) are read-in with a control and arithmetic unit 3 in the rolling mill from a shifting amount table value setting device 4. The product weighting factor Mij , Mij+1 and Mij+2 of the stock concerned, the succeeding stock and the next succeeding stock are read-in from a weight factor setting device 5. The rolling order weighting factor N1 , N2 and N3 of the same are read-in from a rolling order weighting factor setting device 6. The intermediate roll shifting amount is obtained with the arithmetic unit 3 using the formula.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting an intermediate roll shift amount in a hot rolling finishing mill.

[0002]

2. Description of the Related Art Generally, in a hot rolling mill, a method using a work roll bender, an intermediate roll shift, a pair cloth or the like is known in a finishing mill to obtain a target crown or plate shape. Of these, the intermediate roll shift is often adopted because of its excellent shape control performance.
A method in which the operator directly inputs the shift amount based on empirical values, a method in which the shift amount table value for the rolled material is used as it is, the crown and shape of each stand exit side are calculated using a model formula, and optimization calculation is performed. There is a method of determining the shift amount (see, for example, JP-A-55-68110), and the like.

[0003]

However, among the above-mentioned conventional methods, in the operator preset method, the thickness, width, steel grade, etc., of the preceding material, the material concerned, and the following material greatly differ due to roll chance free. Sometimes, 1
Since it is necessary to preset for each book, there is a problem that the sheet passing property is deteriorated due to a change in mill constant. Further, there is a problem in that the crown and the shape are varied due to individual differences among operators.

Further, in the method of directly using the shift amount table value, there is a case where the shift amount largely changes for each rolling coil, which causes a problem such as reduction of rolling efficiency due to APC time. Further, the method of calculating the crown and shape of each stand based on the crown and shape model formula to obtain the optimum shift amount has a problem that the calculation load at the setup becomes high.

An object of the present invention is to provide a method for setting an intermediate roll shift amount in a hot rolling finishing mill, which solves the above problems of the prior art.

[0006]

According to the present invention, in an intermediate roll shift amount setting method for hot rolling using a plurality of six-layer finishing stands equipped with intermediate rolls, the intermediate roll shift amount is preliminarily classified according to steel type and size. An intermediate roll in a hot rolling finishing mill characterized in that the amount of roll shift is determined based on the intermediate roll shift amount table value in consideration of conditions such as the target material, the next material, and the next material. This is a shift amount setting method.

It is also possible to predict the intermediate roll shift amount of the material concerned and the rolled material after the next material, and use the value obtained by weighting and averaging them as the set value of the material concerned.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention. In this figure, 1 is a rolled material P in which six n-fold finishing stands are arranged.
In the hot rolling finishing mill for rolling, each stand is composed of a pair of upper and lower work rolls 11, 11, intermediate rolls 12, 12, and backup rolls 13, 13. Reference numeral 2 is a winding machine for winding the finish-rolled rolled material P. A roll bending mechanism (not shown) for controlling the mechanical crown is attached to each stand.

Reference numeral 3 denotes a rolling mill arithmetic control unit which inputs rolling process information (not shown) and performs various arithmetic operations such as an intermediate roll shift amount to control each stand.
Although not shown in the drawing, the rolling mill arithmetic control device 3
A function for controlling the roll bending mechanism is also provided. Reference numeral 4 is a shift amount table value setting device for setting the intermediate roll shift amount table value according to the steel type and size of the rolled material P at each stand, and 5 is a weighting factor that affects the product accuracy depending on the steel type and size of the rolled material P. Is a product weighting factor setting device, and 6 is a rolling order weighting factor setting device that sets a weighting factor according to the rolling order of the rolled material P. The shift amount table value set in the shift amount table value setting device 4 is determined in advance so that the target product crown, the stand-to-stand shape, and the final product shape can both be achieved well.

Now, the procedure for determining the intermediate roll shift amount SI _ij of the rolled material P of the j-th rolling order in the i-stand will be described. First, for the material for which a rolling instruction is issued, the rolling mill arithmetic control device 3 determines the intermediate roll shift amount of the material (jth), the next material (j + 1th), and the next material (j + 2nd) at the i stand. Table value SI _TBij , SI _{TBij + 1} , SI
_{TBij + 2} is read from the shift amount table value setting device 4. Similarly, the product weighting factors M _ij , M _{ij + 1} , and M _{ij + 2} of the material, the next material, and the next material in the i stand are read from the product weighting coefficient setting device 5. Similarly, the rolling order weighting factors N ₁ , N ₂ , and N ₃ of the material, the next material, and the next material in the i stand are read from the rolling order weighting coefficient setting device 6. Next, the rolling mill arithmetic control device 3 calculates the intermediate roll shift amount SI _ij of the material using the following equation (1).

[0011]

[Equation 1]

The calculated intermediate roll shift amount SI _ij
Then, after correcting the mechanical crown while reducing the shift change amount, it is output to the i-stand and the intermediate roll is shifted. In this way, by weighting the shift amount table values of the material, the next material, and the material one after another, and setting a weighted average value, it is possible to suppress a rapid roll shift change and The decrease can be suppressed.

In the above example, the shift amount table values of the material, the next material, and the next material are weighted, but the predicted value of the shift amount is used instead of the shift amount table value, and the weighted average is used. The set value may be set. That is, if the predicted values of the shift amount of the material, the next material, and the next material are SI _PRij , SI _{PRij + 1} , and SI _{PRij + 2} , respectively,
The intermediate roll shift amount SI _ij of the material is calculated by the following equation (2).

[0014]

[Equation 2]

Further, although the shift amount table value or the shift amount predicted value is described as using three rolled materials of the material, the next material, and the material one after another, the present invention is not limited to this, and four materials are used. It may be more than.

[0016]

[Examples] 4Hi has 4 stands and 6Hi has 3 stands for a total of 7
When rolling the rolled material whose steel type and dimensions are shown in Table 1 using a hot rolling finishing mill including a stand, the method of the present invention is used.
The intermediate roll shift amount was controlled by applying the equation (1).

[0017]

[Table 1]

The change in the set value of the intermediate roll shift amount at the No. 7 stand for each rolling order at that time is shown by the solid line in FIG. For comparison, the data when the same rod is rolled by the conventional method is also shown in the figure by a dotted line. As is clear from this figure, in the method of the present invention, a rapid change in the intermediate roll shift amount is alleviated as compared with the conventional method. As a result, changes in rolling conditions such as the mill constant with the preceding material are reduced, and the effect of stabilizing the threading is obtained.

[0019]

As described above, according to the present invention,
When rolling the material, the intermediate roll shift amount of the next material and the following materials is taken into consideration to set the intermediate roll shift amount of the material, so that abrupt intermediate roll shift is alleviated and the strip running is stabilized. As a result, it is possible to improve the rolling efficiency, the product quality, and the operator's burden.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a transition of an intermediate roll shift amount when the present invention is applied.

[Explanation of symbols]

 1 Hot rolling finishing mill 2 Winding machine 3 Rolling machine calculation control device 4 Shift amount table value setting device 5 Product weight coefficient setting device 6 Rolling forward weight coefficient setting device 11 Work roll 12 Intermediate roll 13 Backup roll P Rolled material

Claims (2)

[Claims] 1. In an intermediate roll shift amount setting method for hot rolling using a plurality of six-layer finishing stands equipped with intermediate rolls, an intermediate roll shift amount table value preliminarily classified according to steel type and size is used as a basis. In addition, a method for setting an intermediate roll shift amount in a hot rolling finishing mill, characterized in that the roll shift amount is determined in consideration of conditions such as the material to be set, the next material, and the next material. 2. The hot rolling according to claim 1, wherein an intermediate roll shift amount of the material and a rolled material after the next material is predicted, and a value obtained by weighting and averaging them is set as the set value of the material. Intermediate roll shift amount setting method in finishing mill.