JP2004216383A - Coil rewinding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil rewinding method for detecting defects such as seizure flaw by utilizing changes in noise when rewinding a coil, and preventing breakage of a plate caused by plate drawing. <P>SOLUTION: When a coil is rewound from a pay-off reel, noise in the predetermined frequency range selected from 5-100 kHz is collected, and the steel plate passing speed is decelerated or stopped if the collected noise exceeds the predetermined threshold for a predetermined time or more. In addition, the steel plate passing speed is preferably decelerated step by step in two or more stages. Position information of the steel plate if the collected noise exceeds the predetermined threshold for a predetermined time or more is preferably transmitted to an inspection step in the post stage. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coil rewinding method that detects a defect such as a shape defect using a change in sound when the coil is rewinded, and prevents a plate from being broken due to a plate drawing.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Publication No. 7-121411
BACKGROUND ART Conventionally, when a steel sheet after batch annealing is rewound from a pay-off reel on a temper rolling line, it is known that seizure flaws are generated with this unwinding operation. This seizure flaw is also called an adhesion flaw, when there is a temperature cycle failure during batch annealing or a winding failure in the previous process, if the shape of the steel sheet is partially poor or there is local deformation, This is a surface defect that occurs on the surface of the steel sheet when the coiled steel sheets are brought into close contact with each other during batch annealing and seizure occurs, and the steel sheet is unwound on the entrance side of the temper rolling mill in the next step. When these flaws occur, if high-speed rolling is performed as it is, sheet drawing will occur and sheet breaking will occur, resulting in lower product yield, lower operating rate of the temper rolling mill, and inconvenience such as changing work rolls of the rolling mill. I was
[0004]
On the other hand, it is empirically known that when the steel sheets are in close contact with each other, a peeling sound is generated when the coil is unwound. Conventionally, when the operator detects the peeling sound, the passing speed of the steel sheet is determined. Then, visual observation and the like were performed at a reduced speed, and measures were taken to prevent the occurrence of plate breakage or the like due to the plate drawing. However, in the factory, various sounds such as noise of peripheral equipment and human voice are generated, and the peeling sound also has a large and small volume, and in such a situation, the operator surely recognizes only the peeling sound. There was a problem that it was almost impossible to extract and distinguish.
[0005]
[Problems to be solved by the invention]
The present invention solves the conventional problems as described above, enables the operator to quantitatively measure the strip peeling sound that the operator has empirically heard and to reliably detect the stripping sound, and to prevent the breakage of the plate due to the drawing of the plate. The present invention has been completed for the purpose of providing a coil rewinding method that can be performed.
[0006]
[Means for Solving the Problems]
A method of rewinding a coil according to the present invention, which has been made to solve the above-described problem, is to collect sound in a specific frequency range selected from 5 to 100 KHz when rewinding the coil from a payoff reel, and collect the collected sound. Is characterized in that, when a predetermined threshold value is exceeded for a predetermined time or more, the sheet passing speed of the steel sheet is reduced or stopped.
[0007]
In order to solve the same problem, a method of stepwise reducing the sheet passing speed of the steel sheet in two or more steps is defined as the invention according to claim 2, and furthermore, the collected sound exceeds a predetermined threshold for a predetermined time or more. The method for transmitting the position information of the steel plate in the case of the above to the subsequent inspection process is defined as the invention according to claim 3.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a case where the present invention is applied to unwinding of a coil in a temper rolling line. In the drawing, reference numeral 1 denotes a temper rolling mill, 2 denotes a pay-off reel on the entrance side of the rolling mill, and 3 denotes a rolling mill. Is a tension reel, 4 is a master speed control device, and M is a drive motor. After rewinding the coil from the payoff reel 2 while controlling each motor M by the control signal of the master speed control device 4, the steel sheet 20 is rolled by the temper rolling mill 1 and wound again by the tension reel 3. The above points are basically the same as the conventional coil rewinding method in the temper rolling line.
[0009]
In the present invention, when the coil is rewound from the payoff reel 2, sound in a specific frequency range selected from 5 to 100 KHz is collected, and when the collected sound exceeds a predetermined threshold for a certain period of time or longer, the steel sheet is removed. The passing speed is reduced or stopped. This is because it has been empirically known that a peeling sound is generated when the coil is rewound if the steel sheets are closely adhered to each other and seized. For example, the present inventors have found that only the peeling sound can be accurately extracted without being affected by noise of peripheral equipment, voice of a person, and the like, and have reached the present invention.
[0010]
The sound in the specific frequency range can be arbitrarily selected from a frequency band of 5 to 100 KHz. This is because, as shown in FIG. 3, when the frequency is less than 5 KHz, the noise becomes a disturbance and it is difficult to catch the occurrence of the peeling sound at the sound pressure level. Therefore, it is preferable to use a frequency of 5 KHz or more, and more than 100 KHz. If it is large, noise other than the peeling noise may be captured, so it is preferable to use a frequency of 100 KHz or less.
FIG. 3 is a graph showing the relationship between the frequency (KHz) in the defective shape portion and the amount of change in the sound pressure level (dB) from a certain reference point. It can be seen that it is captured as a sound pressure difference.
[0011]
In FIG. 1, reference numeral 5 denotes a sound collector, for example, a sound collecting microphone (microphone), an ultrasonic detection sensor, or the like. The sound collected by the sound collector 5 is converted into sound pressure data by a frequency analysis filter 6 including a spectrum analyzer and a filter, and a changed portion of the sound is quantitatively measured as an electric signal. Next, when the sound pressure data is input to the determination device 7 and exceeds a predetermined threshold for a predetermined time or more, control is performed to reduce or stop the sheet passing speed of the steel sheet. Reference numeral 8 denotes an alarm guidance display that issues an alarm when a change in the sound pressure of the peeling sound is detected, and 9 denotes a data processing device that manages the obtained information.
[0012]
FIG. 4 shows an example of the control in the determination device 7, in which a threshold (α) is set, and the sound pressure data of the sound collected by the sound collector 5 exceeds the threshold (α) for a certain period of time or more. In such a case, control is performed to reduce or stop the passing speed.
In FIG. 4, T1 and T2 are detection times (sec), S0, S1, and S2 are threading speeds (m / min). For example, the operation was performed at the initial threading speed S0 (900 to 1800 m / min). In this case, when the time during which the sound pressure data exceeds the threshold value (α: 10 to 50 dB) is equal to or longer than T1 (2 sec), the main speed control device 4 reduces the threading speed to S1 (100 to 300 m / min). Will be controlled automatically. Further, if the time during which the sound pressure data exceeds the threshold value (α) is T2 (4 sec) or more, the master speed control device 4 automatically reduces or stops the threading speed to S2 (0 to 60 m / min). It will be controlled.
[0013]
If the passing speed of the steel sheet is controlled to be gradually reduced in two or more steps as described above, in the case of detection of a small defect, peeling noise, the passing speed is reduced only by a small percentage and observed in the subsequent process. Inspection is performed, and in the case of detecting a peeling sound that leads to a large defect, the passing of the sheet is stopped to prevent the occurrence of a trouble beforehand, which is preferable because high production efficiency can be secured.
After the control is performed to reduce the passing speed, the returning speed automatically returns to the initial passing speed S0 according to an instruction of the operator or after a certain time has elapsed.
[0014]
Further, as shown in FIG. 2, the position information of the steel sheet when the collected sound exceeds a predetermined threshold for a predetermined time or more can be transmitted to a subsequent inspection process. In FIG. 2, reference numeral 11 denotes a flaw inspection device installed at the subsequent stage of the temper rolling mill 1, and the position information of the steel sheet that has generated the peeling sound obtained by the determination device 7 and the information of the flaw inspection device 11 are used as flaw inspection information. By transmitting the information to the analysis device 12, if the information is centrally managed by the data processing device 9, the information can be effectively used in the subsequent next process line, which is preferable.
[0015]
As described above, the present invention collects a sound in a specific frequency range selected from 5 to 100 KHz when rewinding a coil from a payoff reel, and when the collected sound exceeds a predetermined threshold for a predetermined time or more, Since the passing speed of the steel sheet is reduced or stopped, it is possible to accurately and surely detect the change in sound that has been sensed by the operator in the past, and then reduce or stop the passing speed of the steel sheet. Therefore, it is possible to provide a system that does not overlook defects and has excellent work efficiency.
[0016]
【The invention's effect】
As is clear from the above description, the present invention makes it possible to quantitatively measure the strip peeling sound that the operator has heard empirically and detect it reliably, and to prevent the breakage of the plate due to the drawing of the plate. You can do it.
Therefore, the present invention greatly contributes to industrial development as a method of rewinding a coil that has eliminated the conventional problems.
[Brief description of the drawings]
FIG. 1 is an overall flowchart showing an embodiment of the present invention.
FIG. 2 is an overall flowchart showing another embodiment.
FIG. 3 is a graph showing a relationship between a frequency (KHz) and a change amount of a sound pressure level (dB).
FIG. 4 is a graph showing an example of control in a determination device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Temper rolling mill 2 Payoff reel 3 Tension reel 4 Master speed control device 5 Sound collector 6 Frequency analysis filter 7 Judgment device 8 Warning guidance display 9 Data processing device 11 Flaw inspection device 12 Flaw inspection information analysis device

Claims (3)

When rewinding the coil from the payoff reel, a sound in a specific frequency range selected from 5 to 100 KHz is collected, and when the collected sound exceeds a predetermined threshold for a predetermined time or more, the sheet passing speed of the steel sheet is reduced or A method of rewinding a coil, which is stopped. The coil rewinding method according to claim 1, wherein the sheet passing speed of the steel sheet is reduced stepwise in two or more steps. 3. The coil rewinding method according to claim 1, wherein the position information of the steel sheet when the collected sound exceeds a predetermined threshold for a predetermined time or more is transmitted to a subsequent inspection process.

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