JP4261920B2 - Coil rewinding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coil rewinding method that detects a defect such as a defective shape by utilizing a change in sound when the coil is rewound, and prevents plate breakage or the like due to a plate stop.
[0002]
[Prior art]
[Patent Document 1]
Japanese Examined Patent Publication No. 7-121411 [0003]
Conventionally, it is known that when a steel sheet after batch annealing is rewound from a payoff reel on a temper rolling line, seizure flaws are generated along with this rewinding operation. This seizure flaw is also called an adhesion flaw, and when there is a temperature cycle defect during batch annealing, a winding failure in the previous process, a partially bad steel plate shape or 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, seizure occurs, and rewinding is performed on the entrance side of the temper rolling mill in the next step. When this wrinkle occurs, if it is rolled at a high speed as it is, it will cause plate drawing and breakage of the plate, resulting in a decrease in product yield, a reduction in the operating rate of the temper rolling mill, and inconveniences such as reworking of the rolling mill. It was.
[0004]
On the other hand, it is empirically known that when the steel plates are in close contact with each other, a peeling noise is generated when the coil is rewound. The plate was decelerated and visually observed, etc., and measures were taken to prevent plate breakage or the like due to plate drawing. However, in the factory, various sounds such as noise of peripheral equipment and human voice are generated, and the volume of the peeling sound is also varied. Under such circumstances, the operator can surely hear only this 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 above-mentioned conventional problems, enables the operator to quantitatively measure the stripping sound that the operator has heard empirically, and to reliably detect it, and prevents plate breakage due to plate restriction, etc. The present invention has been completed in order to provide a coil rewinding method that can be performed.
[0006]
[Means for Solving the Problems]
The coil rewinding method of the present invention made to solve the above-described problem is that when rewinding the coil from the payoff reel, a sound in a specific frequency range selected from 5 to 100 KHz is collected, and this collected sound is collected. Is converted into sound pressure data, and it is assumed that there is a shape failure when the sound pressure level drops and exceeds a predetermined sound pressure difference threshold value for a certain period of time. It is characterized by decelerating or stopping.
[0007]
Further, in order to solve the same problem, a method of transmitting the position information of the steel plate when the threshold value is exceeded for a certain time or more to the subsequent inspection step is defined as the invention according to claim 2 .
[0008]
DETAILED DESCRIPTION OF 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 coil rewinding in a temper rolling line, in which 1 is a temper rolling mill, 2 is a payoff reel on the entry side of the rolling mill, and 3 is a rolling mill. The tension reel 4 on the exit side of the main body 4 is a master speed control device, and M is a drive motor. And while controlling each motor M with the control signal of the master speed control device 4, the coil is rewound from the payoff reel 2, the steel plate 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 coil unwinding method in the conventional temper rolling line.
[0009]
In the present invention, when the coil is rewound from the payoff reel 2, a sound in a specific frequency range selected from 5 to 100 KHz is collected, and when the collected sound exceeds a predetermined threshold value for a predetermined time or more, the steel plate The plate 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 when the steel sheets are in close contact with each other, and the present inventor can use the sound in a specific frequency range. In other words, the present inventors have found that it is possible to accurately extract only the peeling sound without being affected by noise of peripheral equipment, human voices, or the like.
[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, it is preferable to use a frequency of 5 KHz or more because noise becomes a disturbance at a frequency of less than 5 KHz and it is difficult to detect the occurrence of peeling sound at the sound pressure level. If it is large, there is a risk of capturing noise other than the peeling sound, 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) at 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 regarded as a sound pressure difference.
[0011]
In FIG. 1, reference numeral 5 denotes a sound collector, and for example, a sound collecting microphone (microphone) or an ultrasonic detection sensor is used. The sound collected by the sound collector 5 is converted into sound pressure data by a frequency analysis filter 6 comprising a spectrum analyzer and a filter, and the 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 value for a predetermined time or longer, control is performed to reduce or stop the sheet passing speed of the steel plate. Reference numeral 8 denotes an alarm guidance indicator that issues an alarm when a change in the sound pressure of the peeling sound is detected, and 9 is 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 value (α) is set, and the sound pressure data of the sound collected by the sound collector 5 exceeds the threshold value (α) for a certain time or more. In such a case, control is performed so as to reduce or stop the plate passing speed.
In FIG. 4, T1 and T2 are detection times (sec), S0, S1, and S2 are plate passing speeds (m / min). For example, the operation was performed at the original plate passing speed S0 (900 to 1800 m / min). In this case, if the time when the sound pressure data exceeds the threshold (α: 10 to 50 dB) is equal to or greater than T1 (2 sec), the main speed control device 4 reduces the sheet passing speed to S1 (100 to 300 m / min). Will be automatically controlled. Furthermore, if the time when the sound pressure data exceeds the threshold value (α) is T2 (4 sec) or more, the main speed control device 4 automatically reduces or stops the threading speed to S2 (0 to 60 m / min). Will be controlled.
[0013]
As described above, if the steel plate passing speed is controlled to be gradually reduced in two steps or more, in the case of detecting a peeling sound that is a small defect, only a few percent of the plate passing speed is reduced and observed in the subsequent process. In the case of detecting a peeling sound that leads to a large defect after inspection, it is preferable to stop the threading plate to prevent the occurrence of trouble and to ensure high production efficiency.
In addition, after controlling to decelerate the sheet passing speed, it is automatically returned to the original sheet passing speed S0 according to an instruction from the operator or after a predetermined time has elapsed.
[0014]
Further, as shown in FIG. 2, the position information of the steel plate when the collected sound exceeds a predetermined threshold for a certain time or more can be transmitted to the subsequent inspection process. In FIG. 2, reference numeral 11 denotes a flaw inspection apparatus installed at the subsequent stage of the temper rolling mill 1, and the position information of the steel plate that has generated the peeling sound obtained from the determination apparatus 7 and the information of the flaw inspection apparatus 11 are obtained through inspection information. By transmitting the information to the analysis device 12, it is preferable that the information can be effectively used in the subsequent next process line if the information is centrally managed by the data processing device 9.
[0015]
As described above, when the coil is rewound from the payoff reel, the present invention collects the sound in the specific frequency range selected from 5 to 100 KHz, and the steel plate when the collected sound exceeds a predetermined threshold for a certain time or more. The speed at which the sheet passes is decelerated or stopped, so that the sound changing part that has been detected by the operator in the past can be detected accurately and reliably, and then the sheet passing speed can be reduced or stopped. Therefore, it is possible to provide a system that does not miss defects and that is excellent in work efficiency.
[0016]
【The invention's effect】
As is clear from the above description, the present invention makes it possible to quantitatively measure the stripping sound of the strip that the operator has empirically heard to reliably detect it, and to prevent plate breakage and the like due to the plate stop. It can be done.
Therefore, the present invention greatly contributes to the development of the industry as a coil rewinding method that eliminates 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 change amount of a frequency (KHz) and a sound pressure level (dB).
FIG. 4 is a graph showing an example of control in the determination apparatus.
[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 Alarm guidance display 9 Data processing device 11 Inspection device 12 Inspection information analysis device

Claims (2)

When the coil is rewound from the payoff reel, the sound of a specific frequency range selected from 5 to 100 KHz is collected, the collected sound is converted into sound pressure data, and the sound pressure level is lowered to a predetermined sound pressure difference. A coil rewinding method characterized in that if there is a shape defect when the threshold value of the above is exceeded for a certain time or more , the sheet passing speed of the steel sheet is gradually reduced or stopped in two or more stages . The coil rewinding method according to claim 1, wherein the position information of the steel sheet when the threshold value is exceeded for a certain time or more is transmitted to a subsequent inspection step .

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