JPS60141319A - Sheet-width controlling method of hot-finish rolling mill - Google Patents

Abstract

PURPOSE:To control the width of a strip to be constant by detecting the width or the width deviation of the strip between the stands of a hot finishing mill and regulating the mill-motor speed of an upstream stand basing on the signal obtained by said detection. CONSTITUTION:The width-end position of a strip 2 is detected by disposing an edge-position detector 3 between the stands 1a, 1b of a hot finishing mill, and a sheet-width operation signal obtained from a sheet-width operator 4 is compared with a set sheet-width wignal 6 by a comparison operator 5 to transmit its deviation signal to a mill-motor control device 7. In the control device 7; an output signal corresponding to said deviation signal is transmitted to the mill motor 8a of the upstream 1a, and the tension between the stands 1a, 1b is controlled by regulating the speed of motor 8a. In this way, the width of a strip is controlled into consant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling strip width in a hot finishing rolling mill.

Generally, a hot rapid continuous rolling mill is equipped with a rough rolling mill group and a finishing rolling mill group, each of which has a plurality of stands.The heated slab is first rolled to some extent in the rough rolling mill group, and then the heated slab is rolled by the finishing rolling mill group. Although strips of predetermined dimensions are rolled in batches, the products obtained in this way usually have deviations in width.

The plate width deviations mentioned above are roughly divided into those occurring in the rough rolling mill group and those occurring in the finishing rolling mill group, but the plate width deviation that occurs in the finishing rolling mill group in particular has an important effect on product quality. .

In other words, it goes without saying that the roughing mill group must also roll the strip to a predetermined width, but no matter how much the roughing mill group controls the strip to a predetermined width, the finish rolling mill group cannot control it. If this is not done reliably, the control of the rough rolling mill group will become meaningless.

The causes of the strip width deviation in the finishing rolling mill group are temperature variations due to skid marks, or variations in the passing time of each part of the rolled material in the longitudinal direction between each stand, in other words, the tension that the rolled material is subjected to between the stands. and variations in tension time, etc. However, regardless of the cause, if a deviation occurs in the width of the exit plate of the hot finishing mill,
In the narrow part, there is a risk that the board width will be less than the required width for the finished product, so in the past, the target board width had to be set larger in anticipation of this width deviation. There was a drawback that the hanging was cumbersome and the yield was significantly reduced.

In view of the actual situation, Ming rolled the wood to 1 level with hot rolling + jl.
Measure the strip width or width deviation between the stands,
Based on this signal, the width of the slip plate can be controlled to be constant by adjusting the mill date and time of the -C soil flow stand.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the hot finishing rolling mill, rolling stand Ia.

1b, an edge position detector 3 of the strip 2 is disposed, and the edge position detector 3 detects the width end position of the strip 2. Then, the board width of the strip 2 is simulated by a board width simulator 4 based on the signal of the detected width end position. Furthermore, this sheet width manipulation signal is sent to a comparator 5, where it is compared with a set sheet width signal 6, and the deviation signal is sent to the mill motor control device F1. The output signal from the mill motor 8a of the upstream stand 1a is sent to adjust the speed of the mill motor 8a. As a result, the tension of the strip 2 located between the stands Ia and lb is controlled, and the strip width is controlled to a predetermined width. In addition, 8b is a mill of the downstream stand 1b, and 9, 9 is a looper.

By the way, it is already widely known that the width of the board can be controlled by changing the tension, and it is particularly effective to add a one-way tension. Figure 2 shows the backward tension stress σ0
This is a measurement example showing the relationship between and the plate width change amount Δby (A, TSELIKOV@5TRESSand S'
1RAIN in METΔLROLLING l),
154'). In this example, if a tension of 4N1 is not applied, rolling will cause a width expansion of Abo = 5.6m+a, whereas the rear tension horn stress is, for example, σo = 5kg/
When al12 is added, the actual width expansion amount is Δb=Δb,
It can be seen that μ is reduced to -Δby = 3jmm.

As the edge position detector 3 for the rolled material, for example, the one shown in FIG. 3 can be used. For convenience of explanation, in the figures, each component is indicated by the subscript a,
In addition, the subscript 1) is added to the work υid. In the illustrated example, light emitted from the I-slip 2 is imaged onto a light receiving element 12 through a lens 11 provided at a detector entrance 10.

Since the light receiving element generates a voltage signal proportional to the intensity of light, the plate edge position n can be determined by detecting the voltage change at. In fact, the plate width can be determined using the following formula.

do=Xo-C.

dw = Xw - Cw Here, dD and dw are the edge positions of the drive 1 side and work side, and Cos Cw is 1 of the detector field of view length.
The lengths of 72, Xo and Xw are the plate width lengths C of each of the drive side and work side 8 detected by the detector. Xo,
Xw can be determined from the number of elements on each of the drive side and work side that receive light from the rolled material using the following formula.

Xo '' Lo X order Xw = Lw o+dw can be stopped.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it is of course possible to make various changes without departing from the gist of the present invention.

As explained above, according to the present invention, the speed of the upstream mill motor is adjusted based on the plate width or plate width deviation detected between the stands, and the plate width of the slip I/slip is controlled to be constant by tension control. Therefore, it is not necessary to set a large target board width in consideration of board width deviation as in the conventional method, and the amount of trimming in the finishing stage of the finished product is reduced, resulting in a marked improvement in yield. In addition, since this control method is an online feedback control in which the tension between the stands is corrected until the board width deviation is eliminated, there is no need for complicated operations for control, and the configuration is simple. This excellent effect can be achieved.

4. Drawing (7) I! ! IQ! ';K Nl Founder Figure 1 is an explanatory diagram of a device for implementing the elm width control method of the present invention, Figure 2 is an explanatory diagram showing the relationship between rear tension and plate width change, and Figure 3 is an explanatory diagram of the device for implementing the elm width control method of the present invention. - An example of the position detection device is shown in Figure C.

1a, 11+ are rolling stands, 2 is strips, 3 is 1
Nitsuji position detector, 4 is board width calculator, 5 is comparator,
6 is a setting plate width signal, 1 is a mill motor control device, 8a, 8
b indicates Mil Tanabata.

Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd. Kg/mm"' Figure 3

Claims (1)

[Claims] 1) Detect the strip width or strip width deviation between the stands of a hot finishing mill, adjust the speed of the mill motor of the upstream stand based on the detected value, and A method for controlling strip width of a hot finishing rolling mill, characterized in that the strip width is controlled to be constant by controlling the tension between the stands.