KR20020002108A - A detection method of strip rupture using tension - Google Patents

Abstract

PURPOSE: A detection method of a strip rupture using tension is provided to sense accurately and exactly rupture of a strip which is being transferred inside a furnace by detecting a tension of the strip and comparing the detected value of tension with a value which is used in tension controlling. CONSTITUTION: The method of detecting strip rupture using tension comprises a step of calculating tension differences using tension indicating values transmitted from a tension control part and detected values transmitted from tension detecting sensors(30- 33); a step of performing self-diagnosis by comparing and judging the obtained the absolute values after obtaining absolute values for changes for the detected values from each sensors of the left and right sides of the tension detecting sensors per every one scan(34-41,46,47); and a comparing and judging step of judging cutting of the strip according to the conditions of the tension change calculation step and the self-diagnosis performing step(42-45).

Description

A detection method of strip rupture using tension

The present invention relates to a method for detecting a breakage of a strip in a cold rolling continuous annealing process of steelmaking, and more particularly to a method for detecting breakage of a strip using a tension detection value of the strip.

In general, when the strip is heat-treated in the cold rolling continuous annealing process of the steel mill, the strip is transported by a plurality of driving rolls in the furnace, where the strip is continuously transported with radiant heat under an appropriate temperature depending on its thickness, width, and material. do. However, in this process, since the heat treatment and transfer of the strip is made in the furnace, there is a problem that the operator can not directly check the strip.

In this regard, it was necessary to detect the disconnection caused by abnormal tension or material defect in the strip during transport, without directly checking with the eyes. Therefore, many techniques for this have been reported.

One example of a technique for detecting breakage of a conventional strip is shown in FIG. Referring to the conventional method according to Fig. 1, when the strip is brought into contact with the detection bar 1 when the strip is disconnected during strip transfer by the driving roll, the ground bar 2 integrally formed with the detection bar 1 And a strip contact signal is transmitted to the strip break detection unit 10 through the relay Ry. Accordingly, the strip break detection unit 10 detects the transmitted contact signal and then sends an output signal to the tension control unit 11. Then, the tension control unit 11 performs the subsequent stop control operation in response to the output signal of the strip break detection unit 10.

However, according to this conventional method, the strip scale is contacted by the detection bar 1 through the outer wall frame 4 when the oxidation scale in the furnace occurs due to oxygen inhalation during the strip transfer or when the grounding insulator 3 is broken. Even in this case, since the strip break detection unit 10 generates an output signal, it may cause a malfunction of the subsequent stop control. In addition, the occurrence of such a malfunction causes a line stop, which not only delays the production work time but also degrades the quality of the strip.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to detect the tension of the strip and compare the detected value with the value used for tension control to accurately and accurately disconnect the strip during transfer in the furnace. It is to provide a way to detect.

1 is a block diagram of an apparatus for implementing a conventional strip disconnection detection method;

2 is an overall configuration diagram of an embodiment to which the method of the present invention is applied;

3 is a flowchart of an embodiment to which the method of the present invention is applied.

<Description of the symbols for the main parts of the drawings>

10: strip break detection unit 11: tension control unit

12: tension detection sensor 13: strip disconnection detection sensor

In the strip disconnection detecting method using the tension according to the present invention, the tension variation value is calculated using the tension indication value and the detection value measured by the plurality of tension detection sensors, and the detection value measured by the tension detection sensors. Self-diagnosis using the variation amount, and determining strip breakage according to the state of calculating the tension variation amount and self-diagnosis step.

Hereinafter, a strip disconnection detecting method using tension according to the present invention will be described with reference to the accompanying drawings.

Figure 2 shows an apparatus for spherical strip disconnection detection method of an embodiment of the present invention. As shown in Fig. 2, in conveying strips in a furnace in a cold rolling continuous annealing process, a plurality of strip break detection sensors (12) for detecting a breakage of a strip are provided by a plurality of tension detection sensors (12) for detecting the tension of the conveyed strip. 13 are provided between the outer wall frames 4 of these. In addition, the strip detection sensors 13 each include a detection bar 1.

3 is a flowchart illustrating a strip disconnection detecting method according to an embodiment of the present invention. As shown in FIG. 3, the strip disconnection detecting method can be divided into three stages: calculating a tension variation using a tension indication value transmitted from the tension control unit and a detection value transmitted from the tension detection sensor 12; Self-diagnosis of the tension detection sensor 12 and comparison of the data received from the above steps were performed to determine strip breakage.

Hereinafter, the strip disconnection detecting method of the present invention will be described in detail with reference to FIGS. 2 and 3. The method of the present invention comprises a tension variation calculation step, a self-diagnosis step and a comparative determination step.

In the tension variation calculation step, the difference between the tension indication value transmitted from the tension control unit 11 and the detection value transmitted from the left tension detection sensors among the tension detection sensors 12 is calculated (step 30), and the calculation result is calculated. After calculating the percentage (%) of the tension indication (step 31), and processing the absolute value of the value calculated in this percentage (step 32), the amount of tension variation according to the absolute value processing is compared with a predetermined threshold (tension It is judged whether the variation amount is> 80%) and the result is transmitted to the comparison judgment step (step 33).

In the self-diagnosis step, the detected value transmitted from the left tension sensors among the tension detection sensors 12 is sampled every scan and the variation thereof is calculated (step 34), and the calculated value is processed as an absolute value (step 35). ). Then, the comparison is judged whether or not the variation value sampled at each scan is less than or equal to 15 kg (step 36), and the result is sent to the comparison judgment unit, and the comparison judgment is performed at every scan to determine whether the variation value is less than or equal to 2 kg. If less than that (step 37) and the tension control mode is on, the state of the tension detection sensors 12 is determined to be abnormal (step 46), and the result is sent to the comparison determination unit.

In the same manner, the detected values from the right tension sensors among the tension detection sensors 12 are sampled every scan, and the variation thereof is calculated (step 38), and the calculated value is processed as an absolute value (step 39). ). Then, a comparison is made with respect to the variation value sampled at each scan, and a comparison is made to determine whether the sampled variation value is less than or equal to 15 kg at each scan (step 40), and the result is sent to the comparison judgment unit. Compare and determine whether the sampled variation value is less than or equal to 2 kg (step 41) and transmit the result to the comparison judgment part. In particular, if the result value is less than or equal to 2 kg and the tension control mode is on, the state of the tension detection sensors 12 is determined. It is determined as above (step 47) and an alarm message is output to the operation monitor.

In the comparison judging unit, a combination of the signals transmitted in steps 33, 36, and 40 is determined to be a strip break when all are satisfied (step 42), and a determination according to the working conditions is carried out (step 43). If it is 30mpm or less, delay the strip disconnection signal for a predetermined time (approximately 2 seconds) (step 45). If the selection switch for using the strip disconnection signal is selected on the operation monitor, the strip disconnection signal is transmitted to the tension control unit 11 and the motor control unit ( 15) to follow-up stop control according to strip breaking.

As described above, the strip disconnection control method according to the present invention is useful for minimizing equipment accidents and production stop periods generated when the strip is interrupted during the continuous annealing process, and as a result, it is possible to prevent productivity improvement and deterioration of quality.

Claims (1)

The difference between the tension indication value transmitted from the tension control unit 11 and the detection value transmitted from the left tension detection sensors among the tension detection sensors 12 is calculated, and the calculation result is calculated as a percentage (%) of the tension indication value. A tension variation calculation step of processing an absolute value of the value calculated by this percentage, and comparing the tension variation amount according to the absolute value processing with a predetermined threshold value and transmitting the result to the comparison determination step; The detection value transmitted from the left and right tension detection sensors is sampled at each scan and the variation is calculated and the calculated value is processed as an absolute value, and the sampled variation at each scan is less than or equal to a predetermined value. When the comparison is judged and the result is sent to the comparison determination unit, and the variation value sampled at each scan is less than or equal to the other predetermined value, the comparison judgment is made, and when the tension control mode is on, the state of the tension detection sensors 12 is A self-diagnosis step of determining a to be abnormal and transmitting the result to the comparison determination unit; And A strip breaking detection method using a tension comprising a comparison determination step of determining whether the strip breaking by combining the signals transmitted in the electrical step, and instructing the subsequent stop control to be performed if it is determined that the strip breaking.