KR20110070537A - The method and system to control quality in cold rolling system - Google Patents

Abstract

PURPOSE: A system and a method for controlling quality in a cold rolling system are provided to detect flexural displacement of a steel plate caused by a chatter mark, heat streak and vertical illuminance deviation of the steel plate in the early stage to thereby manufacture a steel sheet with high quality. CONSTITUTION: A system for controlling quality in a cold rolling system comprises a vibration sensor(21), a torque sensor(22), a temperature sensor(23), and a current sensor(24). The vibration sensor, the torque sensor, the temperature sensor and the current sensor measure measurement information such as vibration of a rolling mill, the amount of change of the rolling torque, the amount of temperature change of a steel sheet, and a variation in the driving current of a motor during a rolling process in the cold rolling system. The vibration sensor, the torque sensor, the temperature sensor and the current sensor measure the quality of cold rolled products through a signal variation in the measurement information, generated during a rolling work.

Description

Quality prediction system in cold rolling and its method {The method and system to control quality in cold rolling system}

The present invention early detection of the bending deformation and cutting of the plate due to the chatter mark (heat streak), the upper and lower surface roughness deviation of the steel sheet which is commonly generated in the continuous cold rolling process It is a system and method for predicting abnormalities in high speed cold rolling that can take measures to prevent them. In particular, a vibration sensor, a torque sensor, a temperature sensor, and a current sensor are built in the rolling mill, and each measurement information generated from the sensor is received to diagnose a signal amount in which a defect may occur. The present invention relates to a system for predicting abnormality of quality in cold rolling and a method thereof.

The present invention is a continuous cold rolling equipment referred to in the steel manufacturing process, and refers to a system for producing a plate-shaped steel sheet by pressing a metal through a work roll.

Such continuous cold rolling equipment should obtain an excellent quality steel plate without any defects by detecting abnormal conditions caused by abnormal or abnormal work of the equipment during rolling at a high speed and taking early action. However, conventionally, no effective alternative has been proposed.

1 is a view summarizing the problems raised by the defects and problems of the cold-rolled steel sheet, in particular, stainless steel sheet, with reference to this drawing describes a problem that has occurred in the conventional system.

1 (a) is a widthwise stripe having a constant distance in the longitudinal direction of the steel sheet with a chatter mark. The steel sheet on which these chatter marks have been generated must be scrapped. If the surface of the stainless steel plate is irregularly pressed by the roll, this is because it is difficult to sell.

Next, shown in FIG.1 (b), it is a figure which shows the surface state (right side) of a rolled plate (left side) and the roll at that time as a surface defect called a heat streak. FIG. 1C is a diagram showing the warpage deformation of the steel sheet caused by the change of the state of the upper and lower surfaces of the steel sheet during rolling.

And (d) of FIG. 1 is a phenomenon in which a board is cut | disconnected during rolling. If the plate breaks during rolling, it takes time and cost to process it, and the loss is very large, so care must be taken to prevent the plate from breaking.

In addition, there may be a variety of factors that reduce the quality of the steel sheet, but if the above-described various quality items are not detected at the beginning of the rolling, the entire steel sheet being rolled may be disposed of or may cause equipment accidents. In particular, in the case of continuous cold rolling by joining the preceding coil and the trailing coil, if the quality defect is not detected at the beginning, a greater loss must be taken.

Therefore, in order to solve these problems, conventionally open quality improvement methods have been proposed.

Techniques for detecting the quality of the steel sheet during cold rolling include large surface flaw detection technology, internal flaw detection technology, and pin hole penetration technology. 2 is a view showing a basic concept for the quality inspection technology of the conventional cold rolled steel sheet.

As shown in (a) of FIG. 2, known technologies include prior arts related to surface flaw detection techniques, and there are a number of other patents, including JP1999-311510, JP1997-274016, and JP2000-314707, in addition to JP1994-82389 (Applicant: NSC). It is a method to find the defects of the rolled steel sheet by illuminating the light source on the steel sheet and photographing the reflected light. However, this technique is not very effective because of its low accuracy.

In addition, in Figure 2 (b) shows a steel sheet flaw detection technology, there is a prior patent related to this, in addition to JP2002-022706 (Applicant: UCHIHA-SHI) there are JP2003-215106, JP1989-248050 and the like. . It is a technique for measuring the defects of rolled steel sheets using magnetic force.

Next, as shown in (c) of FIG. 2, prior art related to a technology for detecting a pin hole includes a number of patents, such as JP1990-107951 and JP1984-070425, in addition to US Patent Publication No. US4302105 (Applicant: Erwin Sick). Is being released. This is a method in which a strong light source is illuminated on a rolled steel sheet, and then a detector is measured at the bottom of the steel sheet to see if the light source leaks out to the other side.

However, most of the conventional technologies described above detect quality defects by detecting the surface or the inside of the rolled steel sheet with a measuring instrument, but in fact, continuously cold rolling four to six rolling mills in series. In the rolling line, it is difficult to immediately take action because it is not known at which position the generated defect occurs. In addition, in order to apply all of the conventional detection techniques, the cost for the facility is excessive, and it is difficult to install only in one of the continuous processes.

Further, even with all the above techniques, the problems leading to large losses such as cutting of the plate, and the critical problems of not predicting and preventing the problems during rolling in advance cannot be avoided.

The present invention early detection of the bending deformation and cutting of the plate due to the chatter mark, heat streak, top and bottom roughness deviation of the steel sheet, which is commonly generated in the continuous cold rolling process To provide a system and method for predicting abnormalities in high speed cold rolling of metals so that measures can be taken to prevent them.

To this end, in the present invention, a vibration sensor, a torque sensor, a temperature sensor, and a current sensor are built in the rolling mill, and each of the measurement information generated by the sensor is received to diagnose a signal amount in which a defect may occur. To provide a quality prediction system and method for metal high speed cold rolling which can minimize the failure rate of steel sheet.

According to the present invention, the predictive system having higher quality than that generated during cold rolling may measure measurement information such as vibration generation of rolling mill, change of rolling torque, change of temperature of steel sheet, and change of driving current of motor during rolling process in cold rolling system. Combining vibration sensor, torque sensor, temperature sensor and current sensor which can be measured according to; It is configured to include measuring and preventing the quality abnormality of the cold rolled product produced by the signal change amount of the measurement information generated during the rolling operation.

In addition, the vibration sensor according to the quality abnormality prediction system in the high-speed cold rolling of the present invention, is coupled to a plurality of rolling mills and comprises a detection of the chatter mark (Chatter Mark) and plate breaking on the metal surface.

In addition, the torque sensor according to the quality abnormality prediction system in the metal high speed cold rolling of the present invention is configured to attach to the spindle of the rolling mill to detect the roughness deviation of the upper and lower surfaces of the " L "

In addition, the temperature sensor according to the quality abnormality prediction system in the high-speed cold rolling of the present invention is configured to attach to the steel sheet to be rolled to detect whether the heat streak (heat streak) generation.

In addition, the vibration sensor and the current sensor according to the quality abnormality prediction system in the high-speed cold rolling of the present invention is attached to the motor driving PLC of the rolling mill and the rolling mill, and the slip by the evaluation of the plate breakage and the health of the power transmission mechanism ( and detecting the slip).

In addition, the vibration sensor, the torque sensor, the temperature sensor and the current sensor in accordance with the quality abnormality prediction system in the metal high speed cold rolling of the present invention is connected to the A / D converter and the transmitter; It is configured to include the information to be transmitted to the receiver on the diagnostic equipment side.

Further, according to the present invention, the diagnostic equipment according to the quality abnormality prediction system in the high-speed cold rolling, the diagnostic equipment is configured to include detecting the quality abnormality through the diagnostic program in the PC.

In addition, the communication method of the transmitter and the receiver according to the quality prediction system in the metal high speed cold rolling of the present invention comprises the use of Bluetooth wireless data communication.

Unlike the above-described embodiments, another feature of the present invention is that in the method of predicting abnormalities generated during cold rolling, the vibration of the rolling mill during the rolling process in the cold rolling system, the variation of the rolling torque, the variation of the temperature of the steel sheet, and the motor Measuring measurement information, such as the change amount of the drive current of the over time, and measuring and preventing the quality abnormality of the cold rolled sheet produced through the signal change amount of the measurement information generated during the rolling operation.

In addition, the measurement information, such as vibration generation of the rolling mill, the amount of change of the rolling torque, the temperature change of the steel plate, and the amount of change of the drive current of the motor according to the method for predicting the abnormality of quality in the high-speed cold rolling of the present invention, the vibration sensor, the torque sensor It includes a measurement through a temperature sensor and a current sensor.

In addition, the vibration sensor, the torque sensor, the temperature sensor and the current sensor according to the method for predicting the quality abnormality in the metal high speed cold rolling of the present invention can transmit the measurement information to the receiver of the diagnostic equipment through a separate A / D converter and transmitter. It is configured to include one.

In addition, the vibration sensor according to the method for predicting the quality abnormality in the metal high speed cold rolling of the present invention, the main frequency of the vibration signal is generated 350 Hz <Fm <500 Hz or 800 Hz <Fm <1000 Hz, the upper limit vibration And determining that a chatter mark is generated when Magnitude (M), which is the magnitude of the signal, is M> 30.

In addition, the torque sensor according to the method for predicting the quality abnormality in the high-speed cold rolling of the present invention, when │ △ Q│ / Qt> 10%, it is considered that the top and bottom roughness deviation of the steel sheet is generated, the △ Q is up and down rolling The driving torque deviation of the roll is referred to, and Qt is configured to include the sum of the upper and lower driving torques.

In addition, the temperature sensor according to the method for predicting the quality abnormality in the high-speed cold rolling of the present invention, when the maximum temperature is difficult to fix in the case of 300 stainless steel sheet, Ts> 150 ℃ or Ts> 120 ℃ for 400 stainless steel sheet It is assumed that a heat scratch (hsat streak) has occurred, wherein the Ts is configured to include the temperature of the steel sheet being rolled.

In addition, the vibration and current measurement information of the vibration sensor and the current sensor according to the quality abnormality prediction method in the metal high speed cold rolling of the present invention is-0.3 <Rv <0.3, -0.3 <Ee <0.3 and -0.2 <RMS <0.2 It is assumed that the fracture occurs during rolling when all are satisfied, wherein Rv is representative of frequency domain analysis, Ee is representative of entropy domain analysis, and RMS is representative of time domain analysis.

In addition, the communication method of the transmitter and the receiver according to the method for predicting the quality abnormality in the metal high speed cold rolling of the present invention includes using Bluetooth wireless data communication.

According to the present invention, the use of abnormal quality predicting method in STS high speed cold rolling is caused by chatter mark, heat streak, and upper and lower roughness deviation of steel sheet which are commonly generated in continuous cold rolling process. It is possible to detect the bending deformation and cutting of a plate at an early stage and to take appropriate measures to prevent it.

In addition, according to the present invention, it is convenient to use a method for performing the measurement of the defect using a plurality of sensors and receiving such measurement information through the on-line and is not affected by noise and temperature in the workplace have.

In addition, according to the present invention, there is an advantage that it is possible to obtain a number of effects, such as preventing the occurrence of quality defects of the steel sheet, as well as the prevention of equipment accidents, improve the error rate and productivity.

In addition, according to the present invention, there is an advantage that the utilization is high because it can produce a steel sheet of higher quality by utilizing the existing rolling system as it is.

The present invention relates to a predictive system of abnormal quality generated during cold rolling.

Therefore, a detailed description of the configuration of the present invention and its operation and method together with Figures 1 to 12 shown.

As shown in FIG. 3, the present invention provides measurement information such as vibration generation of the rolling mill 10, change in rolling torque, change in temperature of the steel plate 1, and change in drive current of a motor during a rolling process in a cold rolling system. The vibration sensor 21, the torque sensor 22, the temperature sensor 23, and the current sensor 24, which can be measured over time, are combined. And it is to measure and prevent the quality abnormality of the cold rolled product produced through the signal change amount of the measurement information generated during the rolling operation.

The present invention is not a technique for checking whether the result of rolling is good by inspecting the finished steel sheet 1 after the rolling work is completed. While the rolling is in progress, the change amount measured by the plurality of vibration sensors 21, the torque sensor 22, the temperature sensor 23 and the current sensor 24 installed in the rolling mill 10 is measured and rolled through It is a technique to find the problem of the steel plate 1. To this end, the transmission of signals generated from the vibration sensor 21, the torque sensor 22, the temperature sensor 23, and the current sensor 24 has been calculated by many empirical rules in the process of realizing the present invention. By implementing this through a program, we will try to prevent more accurate measurements and problems. And the problems occurring in the steel sheet is not confirmed through the measurement value of any one sensor, it is possible to measure the quality abnormality of various steel sheets are linked to each other comprehensively.

Looking at the problem that may occur during the rolling process for the sake of explanation once again, there is a plate break that tears or breaks the chatter (Chatter) and the steel sheet (1) itself, in the vibration sensor 21 during the rolling process Predicted using the measured frequency and wavelength. As another problem, the detection of the occurrence of the L-bending and the roughness deviation of the upper and lower surfaces of the steel sheet 1 is measured by the torque sensor 22. In order to determine whether a heat streak is generated, the temperature sensor 23 is realized, and the vibration sensor 21 and the current sensor 24 are slips due to the soundness evaluation of the power transmission mechanism. ) And the plate breakage.

The overall configuration of the inventive system and the way of operation thereof will now be described.

FIG. 3 shows a method for predicting abnormality in the high speed cold rolling of the present invention, in particular a system operating on-line. First, a plurality of sensors exist in the basic configuration of the present invention, which includes a vibration sensor 21, a torque sensor 22, a temperature sensor 23, and a current sensor 24 on the measurement equipment 100 side. It is to detect whether or not the steel sheet 1 quality abnormality during rolling using this equipment. In FIG. 4, various measurement information (= signal) obtained through the above-described measuring apparatus 100 may be analyzed to diagnose whether the rolled cold rolled steel sheet 1 has a quality related problem. 200; implemented with a software program).

That is, the types of sensors included in the measurement equipment (implemented by Hardware; 100) of FIG. 3 to find the problems related to the above quality are more specifically listed as follows. That is, a plurality of vibration sensors 21 attached to the rolling mill are for the detection of chatter and plate break, and the torque sensor 22 is for the detection of roughness deviation of L-curvature, upper and lower surfaces of the steel plate, and temperature sensor ( 23 determines whether a heat streak has occurred. In addition, the current sensor 24 determines the slip based on the soundness evaluation of the power transmission mechanism and detects whether the plate is broken in association with the vibration sensor 21.

More specifically, FIG. 3 shows a state in which a plurality of vibration sensors 21 are attached to the rolling mill. First, the support frame 11 of the rolling mill 10, the end of the spindle 12, the reducer housing and It is attached to other necessary parts. The vibration sensor 21 measures the physical wavelength generated by the friction generated on the surface of the rolling roll and the steel sheet 1 during the rolling process to check whether the abnormality occurs in the metal plate during rolling. It is expected that there are chatter or plate failures using the data empirical method that measured and stored the change of vibration wavelength during rolling in the course of many times in a long time.

In addition, the torque sensor 22 is coupled to the rolling system shown in FIG. 3, and attached to the spindle 12 of the rolling mill 10 to detect a roughness deviation of the upper and lower surfaces of the “L” type bended or steel sheet. By measuring the torque deviation generated in the rolling roll and the spindle according to the rotation is to check whether the abnormality occurs in the steel sheet during rolling.

The temperature sensor 23 is attached to the rolled steel sheet 1 to detect whether a heat streak is generated by heat. That is, the temperature sensor 23 directly attached to the rolled steel sheet 1 measures the heat generated from the rolled steel sheet 1, and if more than necessary temperature is generated, the friction generated in the steel sheet 1 is excessive. The steel sheet 1 during the rolling, which has risen to a too high temperature, is judged and predicted because the hardness of the steel sheet 1 is lowered and heat streaks can be generated even by small vibrations and impacts.

Finally, the vibration sensor 21 and the current sensor 24 are attached to the motor driving PLC of the rolling mill 10 and the rolling mill 10, and slips are generated by evaluating whether plate break occurs and the health of the power transmission mechanism. Detect whether or not. The steel sheet during rolling by analyzing the signals measured by the plurality of vibration sensors 21 and the current data measured by the current sensor attached to the PLC for transmitting the rotational force to the motor for driving the rolling roll of the rolling mill 10 It is to predict the abnormality that occurs in the.

By the way, the rolling system of the present invention is divided into the measurement equipment 100 and the diagnostic equipment 200 as shown in FIG. Although the measurement device 100 may be provided with a diagnostic device 200 connected through a wire, the measurement device 100 and the diagnostic device 200 may be wirelessly connected. That is, the diagnostic equipment determines whether the abnormality occurred in the steel sheet 1 during rolling by utilizing various signals of the measured sensor. To this end, the following components are required in the present invention.

As shown in FIG. 3, the vibration sensor 21, the torque sensor 22, the temperature sensor 23, and the current sensor 24 include an A / D converter 31 and a transmitter 32 as measurement equipment 100. Connected to, and to transmit the information measured by the receiver 33 of the diagnostic equipment 200 side.

And it is preferable that the diagnostic device 200 detects the quality abnormality through the diagnostic program in the PC to the measurement information transmitted to the receiver 33.

That is, since most information, data, and signals measured by the sensors are analog values, they are converted into digital signals using an A / D converter 31. The measured value obtained by converting the measured signal into a digital signal is transmitted to the receiver 33 of the diagnostic device 200 via the transmitter 32 of the measurement device 100. In this case, various transmission methods may be used. Both wireless and wired can be utilized.

However, in the present invention, it is preferable to use the Bluetooth wireless data communication 300 as the communication method between the transmitter 32 and the receiver 33. Bluetooth wireless data communication 300 that divides data into multiple frequency bands and transmits data over multiple frequencies for information or data transfer can be stably applied to a rolling system such as the system of the present invention. In this way, the measured values of the measuring device 100 sensor obtained through the receiver 33 are monitored through a computer in real time so that the progress of the rolling operation can be known.

That is, the measured signal diagnoses the state through a software diagnostic program in the computer shown in FIG. This diagnostic program is provided for data analysis. It is to determine whether each measurement signal is a normal signal or a defect is occurring. If a quality problem is occurring, the operator is notified to take appropriate action. In particular, the hardware (Hardware) shown in Figure 3 of the present invention is installed on all the stands of the continuous rolling mill 10, to accurately determine which stand the generated quality defect signal is appearing on the stand only, the rapid action for the stand only To make it possible. In more detail, the continuous cold rolling system has a plurality of rolling mills to produce a steel sheet through a plurality of rolling process. Therefore, each rolling mill 10 is referred to as a stand, which is a method of measuring in real time according to the progress of time by combining the hardware described above for each stand of each stage, and transmits and diagnoses it. Therefore, by utilizing the system of the present invention, it is possible to check, diagnose and correct in real time the presence or absence of abnormality occurring in the steel sheet 1 during rolling.

The foregoing has described a system for measuring and diagnosing abnormalities occurring in steel sheets during cold rolling operations. However, the present invention is also characterized in that the method for measuring and diagnosing the abnormality of the steel sheet (1) generated during the rolling operation will be described below.

According to the present invention, in the method of predicting abnormalities generated during cold rolling, measurement such as vibration generation of the rolling mill 10, change in rolling torque, change in temperature of the steel sheet, and change in driving current of the motor during the rolling process in the cold rolling system. By measuring the information with time, to measure and prevent the quality abnormality of the cold-rolled steel sheet (1) produced through the signal change amount of the measurement information generated during the rolling operation.

That is, in order to solve all the problems of many steel sheets generated while operating a conventional cold rolling system, the measurement is performed in real time through a plurality of sensors and predicts and diagnoses an abnormality using the measured information.

Problems of the steel sheet that may occur during the rolling operation is a plate fracture that tears or breaks the chatter and the steel sheet itself, L bending, steel plate upper and lower roughness deviation, there is a heat streak. In addition, abnormality of slip and plate breakage may occur due to the soundness evaluation of the power transmission mechanism. In the present invention, all such problems are measured and diagnosed through measurement information such as vibration generation of the rolling mill 10, variation in rolling torque, variation in temperature of the steel sheet, and variation in driving current of the motor. That is, it measures through the said vibration sensor 21, the torque sensor 22, the temperature sensor 23, and the current sensor 24 installed in a rolling system.

3 is a view showing the basic configuration of the present invention in more detail, a plurality of vibration sensors attached to the rolling mill, the torque sensor attached to the spindle, the current sensor attached to the motor drive PLC, and the temperature attached to the upper surface of the steel sheet The sensor is showing.

Accordingly, the vibration sensor 21, the torque sensor 22, the temperature sensor 23, and the current sensor 24, which are such basic hardware, are provided through a separate A / D converter 31 and the transmitter 32 for diagnosis equipment 200. Measurement information can be transmitted to the receiver 33 on the () side. That is, the information or data obtained from the plurality of sensors are digitized, transferred to the receiver of the diagnostic apparatus, and the signals transmitted through a separate diagnostic program are diagnosed.

The method of diagnosis and the numerical value thereof have been accumulated in the form of more accurate data through a number of experiences and processes by the applicant of the present invention, which will be described in more detail.

First, the signal or data measured by the vibration sensor 21 is generated at a frequency of 350 Hz <Fm <500 Hz or 800 Hz <Fm <1000 Hz, and is a reference of the magnitude of vibration that is difficult to fix the upper limit. When Magnitude (M) is M &gt; 30, the signal is analyzed as a generation signal of a chatter mark.

As shown in (a) of FIG. 1, a form for detecting the generation of chatter marks formed on the steel sheet is a vibration signal measured during rolling from a plurality of vibration sensors attached to the rolling systems of FIGS. 3 and 5. It is measured by. That is, it is determined that the chatter mark is generated when the measured data as shown in FIG. 6 (a) is subjected to frequency analysis as shown in FIG. 6 (b) to satisfy the above condition. At this time, the mail frequency according to the frequency analysis result is Fm, and the magnitude (magnitude) of vibration, which is another way of expressing it, is expressed as M. Therefore, when these measured values are maintained for more than 3 seconds while satisfying the following conditions, it is determined that a chatter mark has been generated and actions should be taken.

This exact figure is 350 Hz <Fm <500 Hz and M> 30, as described above. The reason why M is limited to a value higher than 30 is because it is difficult to calculate the maximum value in the present invention. If more than 30 M is generated, the system of the present invention does not need to define a larger maximum value to start sensing, and it is difficult to limit the maximum value because it depends on the type of steel sheet to be rolled down according to each workplace.

Next, the torque sensor 22 used in the present invention is regarded as the occurrence of the top and bottom roughness deviation of the steel sheet when | QQ / Qt> 10%. At this time, ΔQ refers to the deviation of the drive torque of the upper and lower rolling rolls, Qt refers to the sum of the upper and lower drive torque. That is, the occurrence of the roughness deviation of the upper and lower surfaces of the steel sheet is a phenomenon in which an abnormality occurs on the surface of the steel sheet and is measured by the deviation of the spindle torque of the rolling roll generated during the rolling operation.

For example, Figure 8 (a) is a view showing the rolling torque signal of the upper and lower measured during rolling from the torque sensor attached to the mill spindle. Torque deviation of the upper and lower parts was obtained from the measured data, and roughness measurement was performed on the upper and lower surfaces of the rolled steel sheet as shown in FIG. 8B. As a result, when the above conditions are satisfied, it is determined that there is an upper and lower roughness deviation of the steel sheet from the torque signal. Could. Therefore, in the present invention, whether the roughness deviation of the steel sheet can be predicted through the sum of the driving torque deviation of the upper and lower rolling rolls and the upper and lower driving torques.

Next, in the present invention, the temperature sensor 23 is difficult to fix the maximum temperature in the case of the 300-based stainless steel sheet 1, but Ts> 150 ° C or in the case of 400-based stainless steel sheet 1, Ts> 120 ° C A heat streak is considered to have occurred. In this case, Ts is the temperature of the steel sheet to be rolled.

In other words, the detection of the occurrence of heat streak, which is a trace on the surface of the steel sheet due to high heat, is performed by installing a contact thermometer on the upper surface of the steel sheet being rolled and measuring the temperature according to the time change. If it is satisfied that the heat streaks are generated. This is somewhat different depending on the type of the steel sheet. Looking at the stainless steel sheet as an example, in the case of the 300-based STS steel sheet, Ts> 150 ° C., and in the case of the 400-based STS steel plate, Ts> 120 ° C. The measured value of this temperature is also hard to set an upper limit, but in the case of the above-mentioned 150 ° C. and 120 ° C., measures will be taken to prevent further rise in temperature, and there is a particular upper limit which may be different depending on the situation. Did not do it.

Next, the vibration and current measurement information of the vibration sensor 21 and the current sensor 24 are obtained when the plate is being rolled when -0.3 <Rv <0.3, -0.3 <Ee <0.3 and -0.2 <RMS <0.2 are satisfied. Slip due to failure and soundness evaluation of the power transmission mechanism is considered to occur. Where Rv is representative of frequency domain analysis, Ee is representative of entropy domain analysis, and RMS is representative of time domain analysis.

That is, the example of the plate breaking is a vibration signal measured during rolling from the vibration sensor attached to the rolling mill, as shown in Fig. 7 (a). In addition, the measured data is determined to be a condition that can cause plate failure when the characteristic values satisfying the following conditions are clustered through time-domain analysis as shown in FIG.

It is important to apply only when the following conditions are satisfied as a result of extracting the characteristic values of the vibration signal and the current signal. First, -0.3 <Rv <0.3, second, -0.3 <Ee <0.3, and third, -0.2 <RMS <0.2.

Of course, as in the system described above, in the present invention, the communication method of the transmitter 32 and the receiver 33, it is preferable to use the Bluetooth wireless data communication (300).

Then, a detailed description of the drawings shown for a more clear description of the present invention.

9 to 12 show an example of detecting the generation of a chatter mark (chatter mark) which is one of the above quality in the rolling diagram as an embodiment of the present invention, and shows the result of verifying the actual rolling plate. The first to fourth passes shown in FIG. 9 are vibration signals measured from the vibration sensor attached to the rolling mill during rolling, and it can be seen that the magnitude of vibration is rapidly increasing in the third pass, which is likely to proceed to the chatter mark. You can guess the big picture.

10 is a result of analyzing the vibration signal of the third pass of FIG. 9 in more detail. FIG. 10 (a) shows a change amount of the vibration signal with time, and FIG. This is the result of the frequency analysis at the elevated part. The frequency analysis results show the range of frequencies and the intensity, or magnitude, of the frequencies. As can be seen in the figure, it can be seen that the frequency with the greatest intensity is 462 Hz. In addition, as shown in FIG. 11, the three-dimensional analysis of the frequency, that is, the spectrogram, shows that the vibration frequency of 462 Hz is maintained until the end of rolling. From the above results, it can be seen that the vibration characteristic is that the chatter is generated by applying the above-described criteria of the chatter generation.

Furthermore, as a result of examining the surface state of the rolled steel sheet to confirm this, as shown in FIG. 12, a chatter mark was generated in the third pass, which was not generated in the first and second passes. The frequency of the chatter generated from the interval proved that the frequency of 462 Hz in the vibration frequency analysis was 473.3 Hz, which is not much different. Through this, it can be seen that the chatter detection criteria of the present invention presented above are valid.

1 is a view showing the defects occurring in the rolling plate during a typical continuous cold rolling operation,

2 is a view showing a technique for detecting a defect of a conventional cold rolling operation,

3 is a view showing the measurement equipment and diagnostic equipment of the continuous cold rolling system according to the present invention,

4 is a diagram showing a diagnostic program of a diagnostic device according to the present invention;

5 is a diagram illustrating the hardware of the present invention;

6 is a view showing a signal for determining the occurrence of a chatter mark of the present invention,

7 is a view showing a signal for determining the prediction of plate breaking in the present invention,

8 is a view showing a signal in which the deviation of the roughness of the upper and lower surfaces of the steel sheet in the present invention,

9 is a view showing a state in which the vibration signal generated during the rolling operation changed with time in the present invention,

10 is a view showing a frequency analysis of the signal generated during rolling in the present invention,

11 is a view showing a three-dimensional frequency analysis results of the vibration signal generated during rolling in the present invention,

12 is a view showing a form in which a chatter mark appears on a steel sheet during rolling in the present invention.

<Brief description of the major symbols in the drawing shown>

One; Steel plate 10; Rolling mill

11; Frame 12; Spindle

21; Vibration sensor 22; Torque sensor

23; Temperature sensor 24; Current sensor

31; A / D converter 32; transmitter

33; Receiver 100; Measuring equipment

200; Diagnostic equipment

Claims (16)

In the predictive system above the quality generated during cold rolling, Vibration sensor, torque sensor, temperature sensor, and temperature sensor that can measure measurement information such as vibration generation of rolling mill, change of rolling torque, change of temperature of steel plate, and change of driving current of motor in cold rolling system over time By combining current sensors; Quality abnormality prediction system in cold rolling, characterized in that for measuring and preventing the quality abnormality of the cold rolled product produced by the signal change amount of the measurement information generated during the rolling operation. The method of claim 1, The vibration sensor, A quality abnormality predicting system in cold rolling, comprising: coupling a plurality of rolling mills and detecting whether a chatter mark and a plate are broken on a metal surface. The method of claim 1, The torque sensor, A quality abnormality predicting system in cold rolling, comprising: detecting an upper and lower surface roughness deviation of an "L" type bending machine or a steel sheet attached to a spindle of a rolling mill. The method of claim 1, The temperature sensor, A quality abnormality predicting system in cold rolling, comprising: attaching to a rolled steel sheet and detecting whether heat streak is generated by heat. The method of claim 1, The vibration sensor and the current sensor, A quality abnormality predicting system in cold rolling, comprising: attaching a rolling mill to a motor driving PLC of a rolling mill to detect slippage by plate breakage and health evaluation of a power transmission mechanism. The method of claim 1, An A / D converter and a transmitter are connected to the vibration sensor, the torque sensor, the temperature sensor and the current sensor; Quality abnormality predictive system in cold rolling, characterized in that it comprises configured to transmit the information measured by the receiver on the diagnostic equipment side. The method of claim 16, The diagnostic equipment is a quality abnormality predictive system in cold rolling, characterized in that configured to include detecting the quality abnormality through a diagnostic program in the PC measurement information delivered to the receiver. The method of claim 6, The transmitter and receiver communication system, the quality abnormality prediction system in cold rolling, characterized in that using Bluetooth wireless data communication. In the predictive method above the quality generated during cold rolling, Measuring the measurement information such as the generation of vibration of the rolling mill, the change of the rolling torque, the change of the temperature of the steel plate, and the change of the drive current of the motor during the rolling process in the cold rolling system over time Converting the measured signal; Transmitting and receiving the converted signal; Determining the occurrence of a quality defect through the received data; Quality abnormality prediction method in the cold rolling consisting of. 10. The method of claim 9, Measurement information such as vibration generation of the rolling mill, change in rolling torque, change in temperature of steel sheet, and change in drive current of motor, Quality abnormality prediction method in the high-speed cold rolling of the metal, characterized in that it comprises a measurement through a vibration sensor, a torque sensor, a temperature sensor and a current sensor. The method of claim 10, In the cold rolling, the vibration sensor, the torque sensor, the temperature sensor, and the current sensor are configured to transmit measurement information to a receiver of a diagnostic apparatus through a separate A / D converter and a transmitter. Predictive method of quality. The method of claim 11, The vibration sensor, Generation signal of the chatter mark when the main frequency of the vibration signal is 350 Hz <Fm <500 Hz or 800 Hz <Fm <1000 Hz, and Magnitude (M), which is the magnitude of vibration that is hard to fix the upper limit, is M> 30. Quality predictive method in cold rolling, characterized in that comprising the analysis. The method of claim 10, The torque sensor, When │ △ Q│ / Qt> 10%, it is considered that the top and bottom roughness deviation of the steel sheet is generated, wherein ΔQ refers to the drive torque deviation of the top and bottom rolling rolls, and Qt refers to the sum of the top and bottom drive torques. Quality prediction method in cold rolling, characterized in that the. The method of claim 10, The temperature sensor, In the case of the 300-based stainless steel sheet, the maximum temperature is difficult to fix, but in the case of Ts> 150 ℃ or Ts> 120 ℃ in the case of 400-based stainless steel sheet, it is regarded that heat streaks have occurred. Quality abnormality prediction method in cold rolling characterized by including the temperature. The method of claim 10, Vibration and current measurement information of the vibration sensor and the current sensor, Fatigue fracture occurs during rolling when 0.3 <Rv <0.3, -0.3 <Ee <0.3 and -0.2 <RMS <0.2, where Rv is representative of frequency domain analysis and Ee is entropy domain analysis. Representative value, RMS is characterized in that it comprises a time domain analysis representative value quality abnormality prediction method in cold rolling. The method of claim 11, The transmitter and receiver communication method, the quality abnormality prediction method in cold rolling, characterized in that using Bluetooth wireless data communication.

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