JPH04332807A - Method for sensing defect of measured value of spontaneous emission-type steel plate width meter - Google Patents

Abstract

PURPOSE:To sense a defect of a measured value of plate width caused by drop in temperature of a steel plate width end in measuring the plate width of the steel plate being hot-rolled between rolling stands by a spontaneous emission type steel plate width meter which utilizes spontaneous emission (infrared radiation) of the steel plate. CONSTITUTION:Plate width of a steel plate S being hot-rolled is measured by a spontaneous emission type steel plate width meter 4 placed between rolling stands 1, 2 and a lower light source type steel plate width meter 7 which is placed at an outlet side of a final rolling stand and is placed under a steel plate path line respectively so as to obtain difference in measured width values obtained by both width meters 4, 7. On the hand, a value of change in width of the steel plate S due to rolling from the self-illuminating steel plate width meter 4 to the lower light source type steel plate width meter 7 is calculated based on rolling conditions. Deviation between the difference in measured width values and a calculated change value of width is obtained, and when the deviation is larger than a set value, the measured width value obtained by the spontaneous emission steel plate width meter 4 is determined to be defective.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to measuring the width of a steel plate during hot rolling between rolling stands using a self-luminous steel plate width meter that utilizes the self-luminescence (infrared radiation) of the steel plate. , a method for detecting an abnormality in the measured value of a self-luminous steel plate width meter, which determines whether or not the plate width measurement value by the self-luminous steel plate width meter is abnormal, and detects the abnormality of the measured value. It is related to.

0002

[Prior Art] In the process of hot rolling a steel plate (hot strip), in order to control the width of the steel plate, a self-luminous steel plate width meter is installed between rolling stands, and this measures the width of the steel plate. I try to measure it.

[0003] This self-luminous steel sheet width meter is designed to measure the sheet width using the self-luminescence (infrared radiation) of the steel sheet, as shown in FIG. There it is,
Equipped with two CCD cameras 4a1 and 4a2 arranged at a predetermined interval to detect the width end of the steel plate S by capturing self-luminescence (infrared radiation) from the steel plate S during hot rolling. Detection head 4a and CCD cameras 4a1 and 4a2
Board width end signals from and CCD cameras 4a1 and 4a2
The signal processing device 4b calculates the width of the steel plate S based on the distance between (omitted) and is used for sheet width control.

[0004] As a steel plate width meter for measuring the width of a steel plate, a lower light source type steel plate width meter is known. This lower light source type steel plate width meter is designed to measure the width of the steel plate passing over the lower light source by placing the lower light source below the steel plate pass line. Since a looper device is provided to apply an appropriate tension to the passing steel plate and stabilize the rolling condition between the rolling stands, it is difficult to install it between the rolling stands.

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned self-luminous steel plate width meter, the temperature at the width end of the steel plate may be higher than normal, although this happens less frequently, due to the cooling condition of the steel plate S during hot rolling. For example, if the temperature drops to below 600°C, the infrared radiation detection ability of the CCD camera will be below, and the steel plate width will be shorter than the actual width of the steel plate to be measured. There is a problem that the measured value is output. For this reason, conventionally, when measuring the width of a steel plate during hot rolling between rolling stands using a self-luminous steel plate width meter, abnormalities in the measured width of the steel plate due to a drop in temperature at the width edge of the steel plate were detected. Since no measures were taken to prevent this, there was a problem in that sheet width control was performed based on the abnormal value of the sheet width measurement, resulting in the production of steel sheets that deviated from the set sheet width.

The present invention has been made in view of the above points, and when measuring the width of a steel plate during hot rolling between rolling stands using a self-luminous steel plate width meter, the width edge of the steel plate is measured. An object of the present invention is to provide a method for detecting an abnormality in the measured value of a self-luminous steel plate width meter, which is capable of detecting an abnormality in the measured value of the plate width due to a temperature drop in the steel plate.

[0007]

[Means for Solving the Problems] In order to achieve the above object, a method for detecting an abnormality in the measured value of a self-luminous steel plate width meter according to the present invention detects the width of a steel plate during hot rolling by measuring the width of the steel plate at a rolling stand. A self-luminous steel plate width meter is installed between the two, which utilizes the self-luminescence of the steel plate, and a bottom light source type steel plate width meter is installed on the exit side of the final rolling stand and uses a lower light source located below the steel plate pass line. and the difference between the plate width measurement value obtained by the lower light source type steel plate width meter and the plate width measurement value obtained by the self-luminous type steel plate plate width meter, while the self-luminous type steel plate width meter Calculate the plate width change value of the steel plate due to rolling between the steel plate plate width meter and the lower light source type steel plate plate width meter based on the rolling conditions, and calculate the difference between the plate width measurement value and the calculated plate width change value. The present invention is characterized in that the deviation from the self-luminous steel plate width meter is determined to be abnormal if the deviation is larger than a set value.

[0008]

[Operation] The width of the steel plate during hot rolling is measured by a self-luminous steel plate width meter installed between the rolling stands and a lower part installed at the exit side of the final rolling stand, which eliminates measurement errors caused by steel plate temperature. Measure each using a light source type steel plate width meter. The difference ( WA − WB ) is calculated. On the other hand, the changes in the width of the steel plate due to rolling from the self-luminous steel plate width meter to the lower light source type steel plate width meter are calculated by rolling reduction rate, plate thickness,
It is calculated based on the rolling conditions of the hot-rolled steel plate, such as plate tension, plate temperature, and steel type. Then,
Deviation D between the above measured plate width value (WA - WB ) and the calculated plate width change value WC = | (WA - WB ) - WC
| is determined, and the determined deviation D and the set value R are compared.

[0009] When the temperature at the width end of the steel plate drops extremely, the plate width measurement value WB obtained by the self-luminous steel plate width meter becomes a value shorter than the actual plate width. In comparison, the deviation D has a large value. Therefore, when the above deviation D is larger than the set value R as the threshold,
By determining that the plate width measurement value obtained by the self-luminous steel plate width meter is abnormal, the plate width measurement value of the steel plate between rolling stands measured by the self-luminous steel plate width meter is an abnormal value. It is possible to detect something.

0010

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a configuration explanatory diagram showing an example of an apparatus for carrying out the method according to the present invention, and FIG. 2 is a flowchart showing an example of the procedure of an abnormality detection operation of a board width measurement value by the abnormality detection apparatus shown in FIG. 1. be.

In FIG. 1, 1 is the n-th rolling stand of a hot finishing mill, and 2 is the (n-1)th rolling stand one stage before the n-th rolling stand. A looper device 3 is provided below the steel plate pass line between the two rolling stands 1 and 2.

4 is a self-luminous steel plate width meter (see FIG. 3) that measures the width of the steel plate (hot strip) S using its self-luminescence (infrared radiation), as explained above. can be,
The self-luminous steel plate width gauge 4 includes a detection head 4a having two CCD cameras (not shown) arranged on the steel plate pass line, and a detection head 4a that detects the steel plate S based on the plate width end signals from the two CCD cameras. A signal processing device 4b for determining the strip width of the steel sheet S between the two rolling stands 1 and 2 is provided.
is provided to the abnormality detection device 5 and rolling control device 6.

Reference numeral 7 denotes a steel plate width gauge with a lower light source installed on the exit side of the final rolling stand. This lower light source type steel plate width gauge 7 includes a lower light source 7a that is disposed below the steel plate pass line and projects detection light upward, and a lower light source 7a that is disposed above the steel plate pass line to face the lower light source 7a. A detection head 7b has a detector that detects the brightness and darkness at the width end of the steel plate S when the detection light is projected onto the steel plate S, and the width of the steel plate S is determined based on the width edge signal from the detection head 7b. A signal processing device 7c for determining the width of the steel sheet S at the exit side of the final rolling stand is detected by the abnormality detection device 5.
It is given to

The abnormality detection device 5 includes a self-luminous steel plate width meter 4.
This is for determining whether or not the board width measurement value WB obtained by is an abnormal value according to the procedure described later. This abnormality detection device 5 is constituted by a programmed microcomputer, and receives as input the plate width measurement value WB from the self-luminous steel plate width gauge 4 and the plate width measurement from the lower light source type steel plate width gauge 7. value WA, and the rolling conditions such as the rolling reduction rate, plate thickness, plate tension, plate temperature, steel type, etc. regarding the steel plate S by each rolling stand from the (n-1)th rolling stand 2 to the final rolling stand from the rolling control device 6. When the plate width measurement value WB input by the self-luminous steel plate width meter 4 is detected to be an abnormal value, a measurement value abnormality signal E indicating this is output to the rolling control device 6. .

Next, referring to FIGS. 1 and 2, the procedure for detecting an abnormality in the board width measurement value WB performed by the abnormality detection device 5 will be described below. In the description of the flowchart shown in FIG. 2, N1, N2, . . . indicate processing procedure (step) numbers.

First, when hot rolling is started, the rolling control device 6 transmits the rolling reduction rate, plate thickness, and plate tension of the steel plate S by each rolling stand from the (n-1)th rolling stand 2 to the final rolling stand. , plate temperature, steel type, and other rolling conditions are input (step N1). Based on the input rolling conditions, a relational expression between the rolling reduction and the plate width expansion dimension, a relational expression between the plate thickness of the steel plate S and the plate width expansion dimension, a relational expression between the plate tension and the plate width contraction dimension, From a pre-programmed calculation formula such as the relationship between the plate temperature and plate width expansion dimension of the steel plate S, the lower light source type steel plate is calculated from the entry side of the n-th rolling stand 1 where the self-luminous type steel plate width meter 4 is installed. A value of change in the width of the steel plate S due to rolling while reaching the exit side of the final rolling stand where the width gauge 7 is installed, that is, a calculated plate width change value WC is determined (Step N2).

In the subsequent step N3, the plate width measurement value WB from the self-luminous steel plate width meter 4 is read, and the process proceeds to step N3.
4, the plate width measurement value W from the lower light source type steel plate plate width meter 7
Load A. Then, the plate width measurement value WA obtained by the lower light source type steel plate plate width meter 7 and the self-luminous type steel plate plate width meter 4
The difference from the board width measurement value WB obtained by (WA - W
B) (step N5), and the difference between the obtained plate width measurement values (WA - WB) and the above calculated plate width change value WC.
The deviation D=|(WA-WB)-WC| is calculated (step N6).

Next, in step N7, the above deviation D
and the set value R, and it is determined whether the deviation D is larger than the set value R or not. Here, if the deviation D is larger than the set value R, it is determined that the plate width measurement value WB obtained by the self-luminous steel plate width gauge 4 is an abnormal value, and a measurement value abnormality signal indicating this is determined. Output E to the rolling control device 6 (
Step N8). In response to this abnormal signal, the rolling control device 6 temporarily suspends the use of the plate width measurement value WB from the self-luminous steel plate width meter 4 to control the plate width of the steel plate S currently being rolled. If NO in step N7, it is determined that the plate width measurement value WB by the self-luminous steel plate width meter 4 is normal, and the process returns to step N3.

As a result of such an operation, the width measurement value of the steel plate S between the rolling stands 1 and 2 measured by the self-luminous steel plate width gauge 4 is caused by the temperature drop at the width end of the steel plate S. It can be detected that the length is shorter than it actually is. As a result, when controlling the width of the steel plate S using the plate width measurement value WB obtained by the self-luminous steel plate width gauge 4, the steel plate S is hot-rolled with a width wider than the set width. You can prevent this from happening.

[0020]

Effects of the Invention As explained above, in the method for detecting an abnormality in the measurement value of the self-luminous steel plate width meter according to the present invention, the width of the steel plate during hot rolling can be determined by measuring the width of the steel plate installed between the rolling stands. Measurements were made using a self-luminous steel plate width meter that uses self-luminescence and a lower light source type steel plate width meter that uses a lower light source installed on the exit side of the final rolling stand and placed below the steel plate pass line. While calculating the difference between the strip width measurement value at the exit side of the final rolling stand measured by a light-source steel plate width meter and the strip width measurement value between rolling stands measured by a self-luminous steel plate width meter, Calculate the plate width change value of the steel plate due to rolling from the type steel plate width meter to the lower light source type steel plate width meter based on rolling conditions,
The deviation between the above-mentioned plate width measurement value and the above-mentioned calculated plate width change value is calculated, and if this deviation is larger than the set value, the plate width measurement value obtained by the self-luminous steel plate width meter is abnormal. As a result, the width measurement value of the steel plate between the rolling stands measured by the self-luminous steel plate width meter is shorter than the actual value due to the temperature drop at the width edge of the steel plate. can be detected. As a result, when controlling the width of a steel plate using the width measurement value obtained by a self-luminous steel plate width meter, it is possible to prevent the steel plate from being hot-rolled with a width wider than the set width. It can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an example of an apparatus for implementing the method according to the present invention.

FIG. 2 is a flowchart showing an example of a procedure for detecting an abnormality in a board width measurement value by the abnormality detection device shown in FIG. 1;

FIG. 3 is a diagram illustrating the configuration of a self-luminous steel plate width meter according to the present invention.

[Explanation of symbols]

1... n-th rolling stand 2... (n-1)th rolling stand 3... looper device 4... self-luminous steel plate width gauge 4a... detection head of self-luminous steel plate width gauge 4b... self-luminous steel plate width gauge Signal processing device 5...Abnormality detection device 6...Rolling control device 7...Lower light source type steel plate width meter 7a...Lower light source 7b
...Detection head of lower light source type steel plate width meter 7c...Signal processing device of lower light source type steel plate width meter S...Steel plate W A, WB...Plate width measurement value E...Measurement value abnormal signal

Claims (1)

[Claims] Claim 1: The width of a steel plate during hot rolling can be determined by a self-luminous steel plate width gauge installed between rolling stands and utilizing the self-luminescence of the steel plate, and by a self-luminous steel plate width gauge installed on the exit side of the final rolling stand and used to measure the width of the steel plate. A lower light source type steel plate width meter using a lower light source placed below the pass line measures the plate width, and the plate width measurement value obtained by the lower light source type steel plate width meter and the self-emitting type steel plate width meter are measured. While determining the difference from the obtained plate width measurement value, calculate the plate width change value of the steel plate due to rolling between the self-luminous steel plate width meter and the lower light source type steel plate width meter based on the rolling conditions. Calculate the difference between the plate width measurement value and the calculated plate width change value, and if this deviation is larger than the set value, the plate width measurement value obtained by the self-luminous steel plate width meter. 1. A method for detecting an abnormality in a measured value of a self-luminous steel plate width meter, characterized in that the measurement value is determined to be abnormal.