JPH0616891B2 - Rolling control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for controlling rolling of rolled material by a rolling mill, and more specifically, rolling in a rolling mill for continuously rolling rolled material of different widths. The present invention relates to shape control of a plate crown of a material.

[Conventional technology]

In a six-fold rolling mill (for example, HC mill) capable of shifting the intermediate rolls, the intermediate roll shift position and the bender force are determined according to the width of the rolled material in order to control the crown shape.

A conventional batch type rolling mill, for example, Japanese Patent Publication No. 50-19
In the rolling mill disclosed in Japanese Unexamined Patent Publication No. 510, after the rolling of a rolled material is completed and before the next rolled material is passed, the shift of the intermediate roll and the setting of the bending force are performed.

That is, the multiple rolling mill 1 shown in FIG. 4 (in the illustrated embodiment,
As is apparent from the front view of the (HC mill), the rolling mill 1 includes a pair of work rolls 2 that directly apply a rolling force to the rolled material S.
And a pair of intermediate rolls 3 arranged behind the work rolls 2 and a reinforcing roll 4 arranged behind the intermediate rolls 3. In the rolling mill 1, The crown shape of the rolled material S rolled largely depends on the difference Hcδ between the side edge of the rolled material and the side edge of the intermediate roll 3.

Further, this rolling mill 1 controls the bending force Fw acting directly on the rolled material S from the work rolls 2 to control the crown shape of the rolled material S, like the general 4Hi mill. The controllability of the crown shape is also greatly influenced by the difference Hcδ.

The relationship between the crown shape and the difference Hcδ is shown in FIG. 5, and the relationship between the crown shape and the bender Fw is shown in FIG.

According to the relationship between the crown and the difference Hcδ and the relationship between the crown and the bending force Fw shown in FIGS. 5 and 6,
In the rolling mill 1, the intermediate roll 3 is shifted to a position where the difference Hcδ has an appropriate value according to the width of the rolled material S, and the bender force Fw is determined at this position.

[Problems to be solved by the invention]

However, in the continuous type rolling mill, the rolled material S
If the width of the roll changes, the intermediate roll 3
During the shift to the target position, the crown shape of the rolled material S being rolled could not satisfy the target value.

That is, in a continuous type rolling mill that continuously rolls a plurality of rolled materials S before rolling, when the strip width of the rolled material S is changed, the difference Hcδ and the bender force Fw are increased while rolling.
You need to set up.

Since the vendor force Fw is generally controlled by hydraulic pressure, a very fast response can be expected, but since the shift speed of the intermediate roll 3 is limited, it is possible that the intermediate force of the intermediate roll 3 will be delayed. A considerable part near the width changing part of one rolled material S is rolled with a difference Hcδ different from the setup value, and this part becomes a defective crown shape part.

The present invention was devised to solve the above-mentioned problems in the conventional example, and is intended to secure the vicinity of the strip width change portions of a plurality of rolled materials S to a target value of the crown shape. is there.

[Means and Actions for Solving Problems]

Hereinafter, the present invention will be described with reference to FIGS. 1 to 3 showing an embodiment of the present invention.

The rolling method of the rolled material S according to the present invention is such that, in the multiple rolling mill 1 in which the intermediate rolls 3 can be shifted, when the rolled materials S having different widths are continuously rolled, the intermediate rolls are adjusted according to the width of the next rolled material S. 3 While changing the position, that is, changing the difference Hcδ, changing the position of the intermediate roll 3, that is, the difference
According to the change of Hcδ, the bending force Fw is continuously changed and rolling is performed.

That is, the relationship between the difference Hcδ and the bending force Fw under the condition that the crown value is constant is obtained from FIGS. 5 and 6, and the value of the bending force Fw according to the change of the value of the difference Hcδ is obtained from this relationship. In the continuous rolling, the position of the intermediate roll 3 (difference Hcδ) is adjusted according to the width of the next rolled material S while the crown value for the rolled material S currently being rolled is kept constant during continuous rolling. While changing, the bending force Fw is changed so as not to change the crown value in accordance with the change in the value of the difference Hcδ, and at the time when the leading end of the next rolled material S plunges between the work rolls 2 or immediately before, The bender force Fw having a very fast response is quickly set and changed to a value corresponding to the crown value required for the next rolled material S.

At the time of changing the setting of the bending force Fw to the value corresponding to the crown value of the next rolled material S, the position (difference Hcδ) of the intermediate roll 3 with respect to the next rolled material S has moved to the preset position. Therefore, the target difference Hcδ and the bending force Fw for the next rolled material S can be set extremely quickly.

As described above, in the case of the method of the present invention, the rolling action on the rolled material S in the preceding stage is carried out while the crown value set for the rolled material S in the preceding stage is held constant, and the rolling action on the succeeding rolled material S is performed. In the rolling, immediately before the end of the rolling operation for the rolled material S of the preceding stage, without changing the crown value for the rolled material S of the preceding stage, the position of the intermediate roll 3 (the difference Hc
Since δ) has been moved to a position that should be set for the next rolled material S in advance, it can be achieved quickly only by changing the setting of the vendor force Fw with a very fast response. Therefore, defective points of the crown shape of the rolled material S can be suppressed within an extremely narrow range.

In addition, since the formula used for computer setup generally takes the form of a complicated regression formula, it is necessary to perform a convergence calculation to obtain the vendor force Fw from the difference Hcδ under the condition that the crown value is constant. Therefore, the calculation becomes extremely complicated, but in order to compensate for this drawback, the difference in the shift of the intermediate roll 3
It is convenient to approximate the relationship between Hcδ and the vendor force Fw by a quadratic equation of Fw = aHcδ ² + bHcδ + c (a, b, and c are constants).

However, if it is an explicit function form, it is not necessary to stick to the form order.

〔Example〕

In the case of the embodiment shown in FIG. 1, the plate width of the rolled material S supplied by the light projection type plate width detector 5 provided on the entrance side of the rolling mill 1 is detected.

When the change of the plate width of the rolled material S supplied by the plate width detector 5 and the changed value of the plate width are detected, this detection signal is input to the calculator 7.

Between the strip width detector 5 and the rolling mill 1, there is provided a material tracking roll 6 configured by, for example, attaching an PLG to an idle roll, and the material tracking roll 6 transfers to the calculator 7. The calculator 7 calculates the timing at which the next rolled material S having a changed strip width is caught in the rolling mill 1 with reference to the input time point of the detection signal.

At the same time as the above calculation of the biting timing, the calculator 7 calculates a position (difference Hcδ) adapted to the strip width of the next rolled material S according to the detection signal of the strip width detector 5 described above. The calculated signal is output to the shift hydraulic cylinder 13 that shifts the intermediate roll 3 (see FIG. 2) or to the structure (see FIG. 3) in which the shift motor 15 and the screw jack 16 are combined.

The intermediate roll 3 is provided with a shift position detector 10 for detecting a shift movement position of the intermediate roll 3 in the axial direction. When the intermediate roll 3 shifts, the shift position is detected to detect a shift position. The signal from the instrument 10 is input to the calculator 7.

As the shift position detector 10, it is possible to use a magnet scale or a PLG.
It is possible to fix the Magnescale to the intermediate roll chock 12 and the housing 11 and directly detect the shift position of the intermediate roll 3 as the one using the Magnescale. Since it is sensitive to dust, it is not suitable for rolling mills in terms of maintainability.

On the other hand, in the case of using the PLG (see FIG. 2), the rack and pinion device 14 is attached between the intermediate roll chock 12 and the housing 11, and the shift amount of the intermediate roll 3 is changed by using this rack and pinion device 14. When converting the rotation amount to measure the shift amount, as shown in FIG. 3, if an electric shift device using a screw jack is used as the shift device of the intermediate roll 3, the electric motor or the screw jack shaft end is used. The PLG is attached and the shift amount is measured.

The calculator 7 calculates the bender force according to the signal value from the shift position detector 10, controls the opening of the pressure control valve 8 by an amount according to the calculated value, and operates the bender cylinder 9.

As a means for controlling and setting the bender force, as described above, the bender force is generally generated by using the bender cylinder 9 which is a hydraulic cylinder. Therefore, the bender force is changed by changing the hydraulic pressure. Change settings. In an actual rolling mill, an electromagnetic proportional pressure control valve is used to control the hydraulic pressure by an electric signal.

Also in the case of the embodiment shown in FIG. 1, a bender force control system in which this electromagnetic proportional pressure control valve is operated by a command from the calculator 7 is adopted.

In addition, in the case of the illustrated embodiment, the structure in which the bending force is applied to the work roll 2 is shown, but it can be applied to the structure in which the bending force is applied to the intermediate roll 3, and the work roll is also used. The present invention can also be applied to a structure in which a bending force is applied to both 2 and the intermediate roll 3.

〔The invention's effect〕

As is clear from the above description, according to the present invention, when the difference Hcδ is changed, the bending force is changed in accordance with the change in the difference Hcδ, and thus the crown shape of the rolled material is kept constant. It is possible to significantly reduce the occurrence of defective crown shape, which can reduce the occurrence of defective products, and to control the crown shape of the next rolled material to a value that the difference Hcδ is adapted in advance. Since it is set, it is sufficient to change the setting of the vendor force with a fast response speed.
For this reason, similar to the above, the occurrence of defective crown shape of rolled material can be greatly reduced, and the operation can be automatically accomplished by inputting a certain mathematical formula in advance in the calculator, which is extremely simple. It has many excellent effects.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a basic layout configuration for carrying out the method of the present invention. 2 and 3 show examples of the configuration of the shift device and the shift position detector assembled on the intermediate roll. FIG. 4 is a configuration explanatory view of a rolling mill in which the intermediate rolls are shiftable. FIG. 5 is a characteristic diagram between the crown value and the difference. FIG. 6 is a characteristic diagram between the crown value and the bending force. DESCRIPTION OF SYMBOLS 1; rolling mill, 2; work roll, 3; intermediate roll, 4; reinforcing roll, 5; width detector, 6; tracking roll,
7: Calculator, 8: Pressure control valve, 9: Vendor cylinder, 10: Shift position detector, S: Rolled material.

Claims (1)

[Claims] 1. A multiple rolling mill capable of shifting an intermediate roll, when continuously rolling rolled materials having different widths, the above-mentioned width is adjusted in accordance with the width of the next rolled material at a time point near the end of rolling operation of the rolled material. Rolling is performed on the rolled material by changing the intermediate roll position and continuously changing the bender force so as not to change the crown value of the rolled material in accordance with the change of the intermediate roll position. The rolling method in which the bending force is rapidly changed at the same time as the start of the rolling so as to correspond to the changed intermediate roll position to obtain a constant crown value of the next rolled material.