JPH0618656B2 - Roll eccentricity control device - Google Patents

Description

Description: FIELD OF APPLICATION OF THE INVENTION The present invention relates to roll eccentricity control for detecting roll eccentricity in a rolling mill and controlling unit tension.

[Background of the Invention]

Due to the fact that the steel industry in recent years is changing from securing quantity to improving quality and the need to improve operational efficiency, steel strip steel sheets, etc.
The material to be rolled is also required to have high precision and high efficiency productivity. This need is the same in controlling the plate thickness of the rolled material. AGC (Au
A system called tomatic Gage Control) is adopted and is performed by various methods (F / FAGC, BISRA AGC, etc.).

These AGC systems are mainly constructed so as to effectively work on the unevenness of the plate thickness contained in the material to be rolled and the unevenness of the deformation resistance. Therefore, it is difficult to deal with the disturbance generated from the rolling mill itself. Disturbances generated from the rolling mill itself are generally called roll eccentric disturbances, but this roll eccentric disturbance has periodicity, and the present invention predicts the rolling position by this periodicity to absorb the roll eccentric disturbance. It is to try.

The roll eccentricity disturbance and its control are specifically described. As described above, the disturbance generated in synchronization with the cycle of one roll of the rolling mill is called roll eccentric disturbance. Possible roll eccentric disturbances are as shown in Fig. 1 (A) and (B).
2 represented by the relationship between the elasticity curves 1 and 4 and the plasticity curves 3 and 6
There are different types, (1) Eccentricity of the roll itself (This is caused by polishing accuracy of the roll, thermal expansion of the roll itself, etc.
It is thought to move to. (2) Change in pressure distribution generated at each roll rotation due to the structure that supports the roll (It is considered that curve 4 moves to 5 depending on the structure of the key and key groove that fixes the roll and the type of bearing) It can be roughly divided into two.

Roll eccentricity control is due to these roll eccentric disturbances.
It is intended to suppress the roll eccentric disturbance by giving a rolling down command to the rolling down device, which is synchronized with the roll rotation, and which is obtained by multiplying the plate thickness deviation of the rolled material or the load deviation by the rolling reduction-rolled material plate thickness influence coefficient. . It can be seen that there are two types of disturbance here, but there is only one type of control method. For this reason, the conventional roll eccentricity control does not work effectively. Second
Figures (A) and (B) show this detail. What is roll eccentricity control?
This control is intended to control changes in the internal state of the rolling mill, so it is sufficient if the position of the vertical line dropped on the horizontal axis does not change from the intersection of the elastic curve and plasticity curve in the figure. . If the roll eccentricity disturbance is one, if the rolling position is moved by ΔS with respect to the ΔS disturbance in FIG. 2, the elastic curve and the plasticity curve do not change at all, and for the roll eccentricity disturbance of 1, Therefore, the plate thickness of the rolled material does not change. On the other hand, if there are two types of roll eccentric disturbance,
In order to absorb the disturbance in which the elastic curve changes from 4 to 5 in FIG. 2 (B), the reduction position must be moved by ΔS '. By this operation, the elastic curve remains changed and the condition of the rolling mill is changed. Therefore, the change of ΔS 'causes a change in the front / rear tension in the rolling mill to change to plastic curves 6 and 6', and the perpendicular of the intersection of the elastic curve and the plastic curve does not lie on h.

A macroscopic view of this phenomenon is that, as a characteristic of the rolling mill, when the material to be rolled is rolled down, the tension fluctuation of the material to be rolled is promoted by the rolling down, and as a result, the rolling does not work effectively. This tendency is remarkable in the intermediate rolling mill of the tandem rolling mill. Most roll eccentricity is roll eccentric disturbance
The conventional roll eccentricity control, which is the disturbance of (2) and accordingly moves the reduction, was not 100% effective. In addition, in order to further improve the precision of the rolled material, the conventional tandem mill
No. Although only one rolling mill uses the AGC system, there is a tendency to introduce the AGC system into the rolling mills in the subsequent stages. For these rolling mills at the latter stage, a gauge meter gauge type AGC that does not require a special detector or the like is used. Although this AGC is effective against the plate thickness variation of the material to be rolled, it has a drawback that it easily causes its own roll eccentricity disturbance, and it is essential to effectively use the roll eccentricity control. The related invention is disclosed in JP-A-49-8443.
There are issues, etc.

[Object of the Invention]

An object of the present invention is to effectively perform roll eccentricity control by performing appropriate tension control in cold rolling.

[Outline of Invention]

The present invention detects a roll eccentricity amount and its phase, and calculates a reduction amount corresponding to the roll eccentricity amount, and a reduction position control device for controlling the reduction in synchronization with the phase of the roll eccentricity. The apparatus is characterized by including a device that calculates a tension change caused by a change in position and a device that controls the tension in consideration of the propagation delay of the tension, and controls the tension according to the roll eccentricity.

Example of Invention

The present invention, as in the prior art, by the signals of the roll eccentricity detector and the roll eccentricity phase detector, a reduction command signal processed by an appropriate influence coefficient is given to the reduction device of the corresponding rolling mill, and The front and rear tension fluctuations of the corresponding rolling mill caused by fluctuations in the rolling position caused by the signal are predictively obtained, and proper tension control is performed to cancel the tension fluctuations. Hereinafter, the basics of the present invention will be described in detail.

In the present invention, in order to predict the tension fluctuation, a method of determining the influence coefficient to the tension for the roll eccentricity control based on the reduction-tension, and the tension propagation delay to the corresponding rolling mill by the tension control device, A correction method is required.

First, the tension fluctuation is represented by a model of rolling-tension: T = Fc.P, Ve, Vi, H, h, u, ...) P: rolling load, Ve, Vi: incoming and outgoing side rolled material speed, H,
h: plate thickness of material to be rolled, μ: coefficient of friction T can be obtained by partially differentiating the coefficient of friction T by the variable S for reduction. It is also possible to give it empirically. In addition, tension propagation delay is a model of tension generation. tf _i: tension, E: Young's modulus, r: Time L: tension controller-relevant mill, G: are determined Te cowpea tension model and tension control system. Therefore, if the tension control device predicts forward and backward tensions in consideration of these influence coefficients and propagation delays, the tension fluctuations caused by the roll eccentricity control are canceled and the roll eccentricity control becomes effective. can do.

This timing chart is shown in FIGS. 3 (A) to (D). ΔS is moved in correspondence with the base material plate thickness deviation Δh which may be caused by the roll eccentric disturbance. On the other hand, although the change in tension ΔT caused by the movement of ΔS is controlled, as described above, the tension is given the tension command ΔV _Ref earlier by _TL in consideration of the propagation delay. .

The state of tension control is shown in FIGS. When the reduction is moved in the opposite phase in order to absorb Δh, the tension deviation ΔT _S occurs in accordance with this change. Absorption of this tension deviation, ΔT _L
If the change in the tension is applied by the method described above, the tension deviation can be absorbed. Therefore, the plastic curve 6 shown in Fig. 2 →
6 ′ does not change, and the plate thickness of the rolled material becomes h.

Since the roll eccentric disturbance is a periodic disturbance, if tension control is performed at an appropriate timing in synchronization with a device that detects the phase of the roll eccentric disturbance, a special prediction device such as an observer is not required.

FIG. 1 is one of the embodiments of the present invention. A single rolling mill is shown rolling from left to right in the figure. Device 101 for detecting roll eccentricity disturbance
Also serves as a thickness gauge. This detector and the device 102 for detecting the phase of the roll eccentricity disturbance calculate the timing and amount of the roll eccentricity control in the calculation device 107, and command this to the reduction device 103. This roll eccentricity control amount usually has a model for the roll rotational position, and the model is corrected according to the effect of the roll eccentricity control on the corresponding rolling mill. The roll eccentricity disturbance amount and the phase signal of the roll eccentricity are simultaneously stored in the tension control command device 108, and have the same roll eccentricity disturbance model as the roll eccentricity control. Using this model of the amount of eccentric disturbance, the tension fluctuation generated by the roll eccentricity control is canceled in a predictive manner.

A concrete method of tension control is shown in FIG. The above-mentioned 101 and 102 fetch necessary data into the tension influence coefficient calculation device 202 and the tension propagation phase delay calculation device 201, respectively, are calculated, and are given to the tension control command device 108 to perform the tension control. The tension control device is, for example, a rolling roll drive motor, but there is a concern that this tension control command may cause disturbance to the rolling speed. However, since the tension control amount itself corresponding to the roll eccentric disturbance is small and the influence coefficient of the velocity on the tension is about 10: 1, the velocity change is 1/10 for 1 of the tension fluctuation, which is almost a problem. I won't.

Further, in this example, the thickness gauge is used to detect the roll eccentric disturbance, but it is also possible to use the load variation as the roll eccentric disturbance.

FIG. 7 is an example in which the present invention is applied to the second rolling mill of the tandem rolling mill. Device 101 for detecting roll eccentricity disturbance
And a device 102 for detecting the phase of roll eccentricity, a roll eccentricity control command device 108, and a rolling-down device 103. In contrast to this system, the system for performing tension control is the same as that for a single rolling mill, but when the present invention is applied to a tandem rolling mill, interference occurs between rolling mills, so tension control considering this is performed. Add. In the case of a tandem rolling mill, these interferences are complicatedly entangled, but as the material to be rolled becomes the rolling mill in the subsequent stage, the deformation resistance increases, and roll eccentric disturbance of the rolling mill tends to be difficult to transfer to the rolling material. Therefore, the present invention is considered to be sufficiently effective when applied to the first rolling mill or the second rolling mill, and mutual interference is at most
Think about these two. This is shown in Fig. 8 (A).
~ (C).

For example, the tension ΔT between the No. 1 rolling mill exit side and the No. 2 rolling mill
Considering _1-2 , the output side tension of No. 1 rolling mill and No. 2
ΔT _1-2, which is a combination of the operation patterns ΔT ₁ and ΔT ₂ of the entrance tension of the rolling mill, may be used as the tension operation pattern.

If the tension is operated in this pattern, the tension deviation between rolling mills due to roll eccentricity control will be absorbed, and in the end,
Tension deviation will not occur. The same applies between the No. 2 rolling mill and the No. 3 rolling mill. This tension control is not contradictory to the conventional tension control, and may be used in combination with the conventional tension control. In other words, it is a control (feed-forward) to the roll eccentricity control of tension control.

The present invention, the plate thickness accuracy of the material to be rolled, the disturbance that is contained in the material to be rolled in advance, in the single rolling mill, as the number of passes increases, in the tandem rolling mill, On the other hand, in the roll eccentricity disturbance, as the number of passes increases, as the number of passes increases, the rolls are canceled by a roll that cancels this tendency. This is important for making eccentricity control more effective. Further, the system does not have any additional hardware in addition to the conventional rolling equipment, and can be dealt with only by changing the control system software.

〔The invention's effect〕

According to the present invention, a rolling mill of higher quality can be obtained by controlling the tension according to the roll eccentricity.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention, FIGS. 2 and 3 are characteristic explanatory views of rolling mills, FIGS. 4 and 5 are time charts, FIG. 6 is an example of tension control, and FIG. Shows an example in the case of a tandem rolling mill, and FIG. 8 shows a time chart of tension control. H ...... preform thickness, S o _...... pressing position, OS ...... pressing position deviation, the elastic curve of 1-5 ...... mill, plastic curve of 3,6 ...... material to be rolled, Delta] h ...... be rolled Material plate thickness deviation, ΔS …… rolling position deviation, ΔV _Ref …… tension control command, ΔT _L …… tension deviation, _TL …… tension propagation delay time, ΔT _S …… ΔS tension deviation which may be caused by ΔS , ΔT …… actual tension deviation, 101 …… roll eccentricity disturbance detection device, 102 ……
Roll eccentricity phase detection device, 103 ... Rolling down device, 106
...... Rolled material 107 ...... Roll eccentricity control device 108
...... Tension control command device, 109 ...... Tension control device, 20
1 ... Tension propagation delay calculation device, 202 ... Reduction-tension influence coefficient calculation device, ΔT ₁ ... No. 1 rolling mill exit side tension control pattern, ΔT ₂ ... No. 2 rolling mill entry side tension control pattern.

Claims (1)

[Claims] 1. A roll eccentricity control for a cold rolling mill, a detection device for detecting roll eccentricity, a device for detecting the phase of roll eccentricity, and a reduction amount for calculating a reduction amount corresponding to the roll eccentricity amount. A calculation device, a reduction control device that controls the reduction position in synchronization with the phase of the roll eccentricity, a device that calculates a change in the unit tension of the material to be rolled caused by a change in the reduction position, and a tension propagation delay. A roll eccentricity control device, comprising: a device for calculating ## EQU1 ## and a device for controlling the unit tension at a timing in consideration of the delay, and controlling the tension in synchronization with the roll eccentricity control.