JPH07236906A - Device for predicting/controlling miss roll in rolling - Google Patents

Abstract

PURPOSE:To save the man-power based on the improvement of productivity by preventing production impediment, reducing supervisors or the like by making the prediction and control of miss roll in a wire rod and steel bar rolling lines sure. CONSTITUTION:An image picking-up means 4 is provided for always monitoring the loop of the rolling pass line between rolling stands 2n-1, 2n which are ajoined before and behind and a rolled stock 3 is picked up its image at least two places of the just after part on the outlet side of the rolling stand 2n-1 on the front side and intermediate part between both the rolling stands 2n-1, 2n. By compairing the difference between image data which are obtained at least two places by this image pickup means 4 with a threshold value by an image processing means 5, a loop detecting signal is outputted and the rotational speed of roll is controlled into either decreasing the rotational speed of roll of the rolling stand 2n-1 on the front side or increasing the rotational speed of roll of the rolling stand 2n on the rear side by a roll speed control means 6 corresponding to the level of a loop detecting signal which is outputted by this image processing means 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in a wire rod and steel bar rolling line, is a rolling misroll predicting / suppressing device capable of swiftly and accurately detecting and preventing a misroll in a state where the rolling material is not normally caught in the roll. Regarding

[0002]

2. Description of the Related Art As a conventional method for detecting a misroll in a rough rolling row, a timer is used to monitor the time taken for a rolled material to pass between rolling stands so that the rolled material does not get caught in the next rolling stand. A method of checking and a method of visually monitoring by a worker are known. The method will be described with reference to FIG. Rolled material 3 is (n
-1) The time from biting into the stand to biting into the n stand is theoretically expressed as follows. t = L /
V, where L: distance between stands, V: roll peripheral speed = motor rotation speed × (1 / gear ratio) × roll effective diameter,

Now, when the rolled material 3 is bitten into the (n-1) stand, the timer T is started at the same time, and when the timer value T _n when biting into the n stand is T _n > t, n The rolled material 3 is not normally caught in the stand. That is, it is determined that the roll is a misroll, and therefore, the rolling mill upstream of the n-stand is stopped.

On the other hand, the above method will be described with reference to FIG.
The speed of the rolled material 3 changes due to the uneven burning of the rolled material 3,
The loop 13 is formed. The observer judges that this is a sign of the occurrence of a misroll, and lowers the speed of the rolling mill upstream of the n-stand or increases the speed of the downstream rolling mill to prevent the occurrence of the misroll.

[0005]

Regarding the method of [Problems to be Solved by the Invention],
A difference easily occurs between the actual rolling material speed V _O and the roll peripheral speed V. This is because V _O is affected by the variation in the advanced rate of the rolled material, and V is affected by the variation in the roll effective diameter caused by the difference in the contact state between the roll and the material. Therefore, the timer value T _n is not always constant and erroneous detection is likely to occur. It can be said that this method is an effective means for reducing damage after a misroll occurs. On the other hand, with regard to the method (1), it is necessary for an observer to constantly monitor the target stand, but this is extremely difficult, and there is a possibility that the discovery of the loop 13 may be delayed or overlooked. To be done.

For the above reasons, it is still difficult to completely prevent the misroll, and once the misroll occurs, it takes a lot of time to process the misroll, which causes a trouble in production. is there. The present invention has been made in order to solve such problems, and an object of the present invention is to reliably predict and suppress misrolls in a wire rod and a steel bar rolling line and prevent production inhibition. It is to realize labor saving by improving productivity and reducing supervisors.

[0007]

The present invention has the following constitution in order to achieve the above object. That is, the present invention is provided for constantly monitoring a loop of a rolling pass line between rolling stands adjacent to each other in a wire rod and bar rolling line in which continuous rolling is performed by rolls of two or more adjacent rolling stands. An image pickup means for picking up an image of at least two rolled materials, that is, a portion immediately after the exit side of the front rolling stand and an intermediate portion of both rolling stands, and a difference between at least two image data obtained by the image pickup means and a threshold value are compared. The roll rotation speed of the front rolling stand is controlled to the lower side, or the roll rotation speed of the rear rolling stand is controlled in accordance with the level of the loop detection signal output by this image processing means and the loop processing signal for detecting the loop. And a roll speed control means for performing either one of the above control and the roll speed control means.

The present invention also relates to the above-mentioned rolling misroll prediction /
In the restraint device, in both of the rolling stands adjacent to each other in the front and rear, unless a series of rolled material is present at the same time,
It is characterized in that an interlock means for disabling at least one of the loop detection and the roll speed control is provided. Further, according to the present invention, the image processing means binarizes at least two pieces of image data from the image pickup means in the windows of the predetermined regions, obtains the center of gravity of each obtained binarized image, and then, It is characterized by comprising image data determination means for determining a difference in image data based on a difference in center of gravity.

[0009]

According to the present invention, the dynamics of the rolled material in the rolling pass line between the rolling stands adjacent to the front and the rear are imaged at a minimum of two places, that is, the portion immediately after the exit side of the front rolling stand and the intermediate portion of both rolling stands. It is imaged by means. The difference in the image data obtained by the image pickup is compared with the threshold value by the image processing means, and when the loop detection signal having the larger difference is output, the roll speed control means outputs the control signal. This control output is a signal for controlling the roll rotation speed of the front side rolling stand to the lower side, and in this case, the larger the difference in the image data is with respect to the threshold value, the more the loop detection signal A control output is issued to greatly reduce the roll rotation speed in accordance with the level. By operating in this way, it is possible to reliably predict and suppress misrolls.

Further, according to the present invention, at least one of the loop detection and the roll speed control is not activated unless the rolled material is present at both of the rolling stands adjacent to each other in the front and rear. By providing the interlocking means, it is possible to prevent the roll speed from being erroneously detected as a misroll state in spite of the normal operating state, and the accuracy of the misroll prediction can be increased.

Further, according to the present invention, at least two image data from the image pickup means are binarized in the window of the predetermined area to the image processing means, and each of the obtained binarized images is processed. Image data determination means is provided for determining the difference in image data based on the difference in the center of gravity after determining the center of gravity. By providing this image data determination means, it is possible to remove noise in the image and perform more reliable misroll prediction and suppression.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a misroll prediction / suppression system according to an embodiment of the present invention.
3 is a flow chart for explaining the operation of the misroll prediction / suppression system in FIG. 1. Including a front rolling stand 2 _n-1 and a rear rolling stand 2 _n, which are adjacent to each other, two or more rolling stands 2, ... Adjacent to each other are provided. The misroll prediction / suppression system is provided for the wire rod and bar steel hot rolling line 1 to be rolled. This misroll prediction / suppression system includes an image pickup means 4, an image processing means 5, and
The roll speed control means 6 is included.

The image pickup means 4 comprises an image pickup device having a photoelectric conversion type camera such as a CCD (charge-coupled device) camera as an element, and the light receiving axis of the lens is located immediately after the exit side of the front rolling stand 2 _n-1 and at the rear side. The wire rod 3 between the rolling stand 2 _n and the portion immediately before the entrance side is oriented so as to be imaged. Incorporation of the image to the imaging device 4, by using the feature that the wire 3 is a rolling material is self-luminous red, performed using a band-pass filter 10 of the red light transmission, front rolling stand 2 _n A minimum of two wire rods 3 are imaged immediately after the exit side of _-1 and between the rolling stands 2 _n-1 and 2 _n . This means that the loop in the rolling pass line has a small amount of fluctuation immediately after the exit side of the front rolling stand 2 _n-1 , and on the other hand, in the middle part of both rolling stands 2 _n-1 and 2 _n , especially in the central part. Alternatively, it is based on the phenomenon that the amount of fluctuation increases slightly in the portion near the rear rolling stand 2 _n .

On the other hand, the image processing means 5 is provided so that the image signal from the image pickup device 4 can be introduced therein, and compares the difference between the image data (image signal) at two points from the image pickup device 4 with a threshold value. It is designed to detect loops. The image processing means 5 comprises an image data judging means 7 realized by an image processing circuit and a tracking loop detecting section 8 for calculating and outputting a detection signal corresponding to the loop amount. After binarizing each of the image signals in a window 11 having a predetermined rectangular area (see FIG. 1) to remove noise, the center of gravity of each binarized image obtained was determined. After that, the difference in the image data is determined based on the difference in the center of gravity. Here, the binarization means quantization when the number of levels is 2, and for a sample value that takes a continuous value in a certain amplitude range, divides this into sections for each predetermined amplitude and the range. All of the values in the figure mean the operation represented by one representative value of 0 or 1 within that range. The image signal binarized in the window 11 in this way further determines a value determined by the relation of where in the window 11 the image of the wire 3 is located in the vertical direction, that is, the center of gravity. From the difference in the center of gravity of the binarized image thus obtained, the wire 3
It is possible to accurately determine the magnitude of the variation amount of the loop 13 in. Next, the tracking loop detection unit 8 compares the difference between the image signals represented by the difference in the center of gravity of the binarized image introduced from the image processing circuit 7 with a preset threshold value, When the difference is larger, the loop detection signal corresponding to the level is output.

The roll speed control means 6 is an image processing means 5.
When the loop detection signal from the front rolling stand 2 _n-1 is input, the level of the loop detection signal, that is, the variation amount of the loop 13 determined from the difference in the center of gravity of the binarized image, is input to the front rolling stand 2 _n-1 . The control output for changing the operation amount of the motor speed is output to the motor 9 that rotationally drives the roll. That is, an output for controlling the rotation speed of the roll of the front rolling stand 2 _n-1 to be lowered is output. The correction amount of the motor speed in this case is obtained as follows. As shown in FIG. 3 which is an explanatory view of the principle of calculating the loop amount, ΔL≈L-2 {(L / 2) ² + l ² } ^1/2 (1) However, L: extra by the loop 13 Length, L: distance between axes of both rolling stands 2 _n-1 and 2 _n , l: amount of vertical fluctuation of loop, and this ΔL is corrected by one scan time T _S of the roll speed control means 6. In order to do so, it is understood that it is necessary to correct only Δv = ΔL / T _S (2).

In the embodiment described above, the loop is detected under the condition that one wire 3 is simultaneously engaged with the front side rolling stand 2 _n-1 and the rear side rolling stand 2 _n with respect to the tracking loop detector 8. It is possible to add an interlock means 12 that performs detection and roll speed control, and otherwise does not perform loop detection and / or roll speed control. By providing this, the accuracy of misroll prediction can be further improved. Can be increased.

Next, the operation of the misroll prediction / suppression system will be described with reference to FIG. When the operation of this system is started, both rolling stands 2 are moved by the imaging device 4.
Imaging of the rolling pass line between _n-1 and _2n is performed. When the image signal is output from the image pickup device 4, the process proceeds to step S ₁ , the image processing circuit 7 of the image processing means 5 performs the binarization process of the image signal, and further, in the order of step S _{2 and} step S ₃ . After the transition, calculation of the center of gravity W _A in the window 11A in the front rolling stand 2 _n-1 and the rear rolling stand 2
A calculation of the center of gravity W _B within the window 11B at _n is made. Image signal difference represented by the center of gravity difference of the binarized image calculated by the image processing circuit 7 (ΔW = | W _A −W _B |)
Are introduced into the tracking loop detector 8 of the image processing means 5.

In the tracking loop detector 8, the difference ΔW between the image signals and two threshold values C _{1 and} C ₂ (where C ₁ >
C ₂ ) is compared in the order of step S _{4 and} step S ₅ , and if ΔW> C ₁ , the process proceeds to the next step S ₆ , and if C ₁ ≧ ΔW> C ₂ , then Then, the process proceeds to step S ₇ . Both step S _6, S ₇ is a step corresponding to the operation of the interlocking means 12, it is interlocked that bite into one wire 3 at the same time both roll stand 2 of the _n-1, 2 _n When checked by the means 12, the next step S _8, the roll speed control means 6 is actuated by each transition to step S _9, the rotational speed of the motor 9 delta
The control output for speed correction is output so as to decrease by N ₁ or ΔN ₂ (however, ΔN ₁ > ΔN ₂ ), and therefore, the roll speed of the front rolling stand 2 _n-1 is decreased and the misroll is eliminated. It will be. Needless to say, the speed correction amount in this case is set to the value obtained by the above equation (2).

In the embodiment described above, an example of control in which the roll speed of the front rolling stand 2 _n-1 is reduced by the roll speed control means 6 is given. However, the present invention is not limited to this. Needless to say, even if the roll speed control means 6 is controlled to increase the roll speed of _n , the same effect is obtained, and such an example is also included in the scope of the present invention. .

[0020]

As described above, according to the present invention, at least two rolled materials, that is, the portion immediately after the front side of the rolling stand on the outgoing side and the intermediate portion of both the front and rear rolling stands, are imaged by the imaging means, and this imaging is performed. The image processing means outputs a loop detection signal by comparing the difference between at least two image data obtained by the means with a threshold value, and the roll speed control means outputs the loop detection signal corresponding to the level of the loop detection signal output by the image processing means. Since the roll rotation speed of the front rolling stand is reduced or the control output for increasing the roll rotation speed of the rear rolling stand is output, it is possible to accurately and quickly predict and suppress the miss roll, Production can be prevented from being hindered by misrolls, and productivity can be improved. At the same time, labor can be saved by reducing the number of supervisors.

Further, according to the present invention, at least one of the loop detection and the roll speed control is not activated unless a series of rolled materials are present at the both rolling stands adjacent to each other in the front and rear. By providing the interlocking means, it is possible to prevent erroneous detection of misroll, improve detection accuracy, and improve reliability. Further, according to the present invention, at least two image data from the image pickup means are binarized in a window of a predetermined area, the centroids of the obtained binarized images are obtained, and then the centroid difference is calculated. By providing the image processing means with the image data determination means for determining the difference between the image data, there is an advantage that the loop amount can be accurately detected without being affected by noise and the detection accuracy can be further improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a misroll prediction / suppression system according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the misroll prediction / suppression system in FIG.

FIG. 3 is a diagram illustrating the principle of calculating a loop amount.

FIG. 4 is an explanatory diagram of an example of a conventional method for detecting a misroll in a rough rolling row.

FIG. 5 is an explanatory diagram of another example of a conventional method for detecting a misroll in a rough rolling row.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wire / bar steel hot rolling line 2 _n-1 ... Front rolling stand 2 _n ... Rear rolling stand 3 ... Rolled material (wire) 4 ... Imaging means 5 ... Image processing means 5 6 ... Roll speed control means 7 ... Image Data determination means 8 ... Tracking loop detection section 9 ... Motor 10 ... Band pass filter 11 ... Window 12 ... Interlock means 13 ... Loop

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B21B 37/78 G01B 11/24 G 8315-4E B21B 37/00 137 B

Claims (3)

[Claims] 1. In a wire rod and bar rolling line in which continuous rolling is performed by rolls of two or more adjacent rolling stands, it is provided to constantly monitor a loop of a rolling pass line between adjacent rolling stands in front of and behind. An image pickup means for picking up an image of at least two rolled materials, that is, a portion immediately after the exit side of the front rolling stand and an intermediate portion of both rolling stands, and a difference between at least two image data obtained by this image pickup means and a threshold value are compared. Then, the roll rotation speed of the front rolling stand is controlled to the lower side, or the roll rotation speed of the rear rolling stand is controlled depending on the image processing means for detecting the loop and the level of the loop detection signal output by this image processing means. And a roll speed control means for performing either one of the above-mentioned control and the roll speed control. 2. An interlock for preventing at least one of loop detection and roll speed control from operating unless a series of rolled materials are present simultaneously on both of the rolling stands adjacent to each other in the front and rear. The rolling misroll prediction / suppression device according to claim 1, further comprising means. 3. The image processing means binarizes at least two image data from the image pickup means in a window of a predetermined area, obtains the center of gravity of each obtained binarized image, and then, The rolling misroll prediction / suppression apparatus according to claim 1 or 2, further comprising image data determination means for determining a difference in image data based on a difference in center of gravity.