JP2000158044A - Chattering detection method and apparatus for cold rolling mill - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To accurately detect chattering irrespective of noise or mechanical impact in a place. SOLUTION: During cold rolling, only when a waveform component unique to chattering exists in both an acoustic waveform detected near the rolling mill and a vibration waveform detected by the rolling mill or the auxiliary roll device 12 between stands. Consider chattering.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting chattering in a cold rolling mill, and more particularly to a method and apparatus for detecting a chattering occurring during cold rolling of a steel strip. The present invention relates to a method and an apparatus for detecting chattering in a rolling mill.

2. Description of the Related Art In general, in the rolling operation of a sheet, Suzuki "Rolling Hyakutan"("Research on Machinery", Vol. 48, No. 5, 583)
~ 588), a vibration phenomenon of a rolling mill called chattering may occur. In a plate rolled while this chattering is continuing, if the vibration is mild, on both the front and back surfaces of the plate, a horizontal stripe pattern arranged at a constant pitch in the direction perpendicular to the rolling direction is observed, If the level of vibration is high, the thickness of the rolled sheet will fluctuate periodically, and in extreme cases the minimum thickness may even be less than half of the maximum thickness, If
In some cases, the plate may break. Such a chattering phenomenon, even in the case of mild, even if the striped product or the plate product in which the thickness variation has occurred, as a defective portion, must be cut off in the next step or intermediate step, Not only does the production cost worsen due to a decrease in product yield and extra care work, but in the event of a sheet break, the rolling line must be stopped for a long time, greatly affecting production efficiency. Therefore, detection of the chattering phenomenon is important. Also, in most cases, if a small vibration occurs first, this chattering develops into a large vibration within a few seconds. Therefore, in a daily operation, the occurrence of chattering can be detected with high sensitivity and speed. Therefore, it is necessary to take measures such as reducing the rolling speed. Therefore, various methods and apparatuses for detecting chattering have been conventionally proposed. For example, in JP-A-8-141612, chattering is detected by filtering a detection signal from a vibration sensor provided in a rolling mill with a pass characteristic set based on each operating condition of the rolling mill. It is described. Also, in Japanese Patent Publication No. Hei 6-35004, a vibration speed sensor was attached to the housing of the cold rolling mill, and the vibration of this sensor was passed through a filter that passed only the vibration in the natural vibration frequency band of the rolling mill, and passed through this filter. It describes that chattering is detected by an output signal. In Japanese Patent Publication No. 3-50602, if the vibration frequency of the housing detected by a vibrometer installed on the housing of the cold rolling mill is the natural frequency of the mill, the vibration speed exceeds a certain value. It describes that chattering is prevented by controlling the rolling conditions of the mill at the time. In Japanese Patent Application Laid-Open No. 8-108205, vibration detectors are installed at one or more points in each section of a rolling mill to detect the vibration of each section of the rolling mill during operation, and the frequency of vibration displacement, vibration speed or vibration acceleration of each section. Analyze and further analyze the frequency of rolling parameters such as rolling mill tension, rolling torque, rolling speed, etc., which occur from mill natural frequency, gear meshing, bearing failure, spindle-roll coupling failure, and roll flaws. It describes that a natural vibration frequency is calculated and used as a fundamental frequency, and that chattering is determined to occur when a frequency component that is an integral multiple of the fundamental frequency in the frequency analysis result of the actually measured value exceeds a set value.

In the above prior arts, chattering detection is performed based on a detection signal of a vibration sensor installed at one or more locations of a rolling mill. These vibration sensors do not always detect only the vibration caused by chattering, and in the frequency band that is the frequency component of chattering in these prior arts, if a frequency component such as vibration of a rolling mill drive system is included. Erroneously detected as chattering. In particular, in a continuous cold rolling mill that has become popular today, impact vibration often occurs when a connection point of a material to be rolled passes through a mill. Contains the components of the frequency band of chattering, so that it is likely to cause an erroneous detection in the method using vibration as described above. Further, in the prior art as described above, since the vibration sensor needs to be installed in the rolling mill main body, operations such as calibration and inspection of the sensor have to be performed in the line when the line is stopped. There is also a problem in that maintenance is time-consuming, for example, the line must be stopped in order to take measures when an error occurs. or,
In the apparatus according to Japanese Patent Application Laid-Open No. H08-108205, it is necessary to analyze the frequency of each part of the rolling mill and the output of each rolling parameter, and furthermore, to analyze or calculate the theoretical frequency based on mechanical abnormalities every moment. growing.
In addition, the vibrations caused by these mechanical system abnormalities and the actual vibrations of the rolling parameters are only necessary conditions for chattering occurrence factors, and the occurrence of chattering due to other factors and the mechanical system abnormalities and rolling parameters that do not lead to chattering are overlooked. There is a problem that there is a risk of erroneously detecting the vibration of the device. In Japanese Patent Publication No. 5-87325, the thickness of a sheet is measured at two or more locations at intervals of approximately half the pitch of the thickness variation occurring in the longitudinal direction of the material to be rolled. It describes that occurrence of chattering is detected when the difference in thickness is equal to or greater than a preset value. However, the thickness variation of the rolled sheet due to chattering generated in cold rolling is 1 to several μm, the detection resolution of the thickness gauge is insufficient, and a radiation type thickness gauge which is generally expensive equipment, There is a problem in that two devices need to be installed close to each other in a place where only one device is required, which increases the equipment cost. As another method, Japanese Patent Application Laid-Open No.
According to -137512, in a cold rolling mill, a sound unique to chattering generated during rolling of a material to be rolled was converted into an electric signal by an acoustic sensor, and the magnitude of the electric signal became equal to or greater than a set value. , Detecting chattering occurrence. In particular, as a first embodiment, as shown in FIG. 1, the sound near each rolling mill (rolling stand) 11 of the cold rolling mill unit 10 is used as a microphone 14 as an acoustic sensor.
Is converted into an electric signal by a band-pass filter (BPF) 2
After passing only the chattering frequency band in 2, the integration circuit 23 integrates the output of the band-pass filter over a predetermined time length, and the comparison circuit 29 generates a chattering detection signal when the integrated signal exceeds a set value. It is stated that it occurs. In the figure, reference numeral 8 denotes a material to be rolled, 31 denotes a drive circuit, and 32 denotes an acoustic device. Also, as another embodiment,
As shown in FIG. 2, the same microphone 1 as in the first embodiment
4, a frequency analysis circuit 42 for frequency-analyzing the electric signal output from the microphone, a hand-pass filter 22 for extracting a frequency component unique to chattering from an output of the frequency analysis circuit, and an output of the band-pass filter. Also, a circuit including a comparison circuit 29 similar to that in the first embodiment for outputting a chattering generation signal when the magnitude of the extracted signal becomes equal to or larger than a set value is described. However, in the first embodiment, the waveform output from the bandpass filter remains an AC waveform, and even if this waveform is integrated for a certain period of time, the integrated value becomes almost zero. It is not possible to detect a phenomenon in which the amplitude of a particular frequency component increases. In the second embodiment, the frequency analysis circuit generally has no function of outputting a waveform signal, and it is difficult to obtain chattering occurrence information from a bandpass filter. Furthermore,
Since the sound detected by the acoustic sensor is simply distinguished only by the frequency component, if noise containing the same frequency component as chattering occurs elsewhere in the rolling mill, it is easy to mistakenly detect that chattering has occurred. There were also problems. The present invention has been made in order to solve the above-described problems, and is harmful to noise such as noise caused by operations other than the rolling operation and impact vibration applied to equipment having a rolling mill or an auxiliary roll between stands. An object of the present invention is to reliably detect occurrence of chattering during a cold rolling operation with a simple configuration without causing a problem.

According to a first aspect of the present invention, there is provided a cold rolling mill, comprising: an acoustic waveform observed near a cold rolling mill during rolling of a material to be rolled; Or, in both of the vibration waveforms observed by the inter-stand auxiliary roll device, when the waveform component specific to chatter exceeds a set reference value, the occurrence of chattering is detected to solve the above problem. It is. The invention according to claim 2 is characterized in that during rolling of the material to be rolled in the cold rolling mill,
The acoustic waveform observed in the vicinity of the cold rolling mill is converted into an electric signal, a component of a frequency band characteristic of chattering is extracted from the electric signal, and when its effective intensity is equal to or more than a set value, The above problem is also solved by detecting occurrence of chattering. According to a third aspect of the present invention, in the second aspect of the invention, a band-pass filter having a predetermined bandwidth for extracting a component of a frequency band characteristic of chattering from the electric signal. This is to be processed. Claim 4
The invention described in the above, in the chattering detection device of the cold rolling mill, the acoustic waveform observation means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, between the cold rolling mill or its stand A vibration detecting means for detecting a vibration waveform of the auxiliary roll device, a band-pass filter for passing only components of a predetermined frequency band of the acoustic waveform and the vibration waveform, respectively, and a band-pass filter output of the acoustic waveform and the vibration waveform And a means for outputting an alarm when the amplitude of each exceeds a preset value. The invention according to claim 5 is a chattering detection device for a cold rolling mill, wherein an acoustic waveform observing means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, a cold rolling mill or Vibration detecting means for detecting a vibration waveform of the auxiliary roll device between stands,
Frequency characteristic calculating means for calculating the frequency spectrum of the acoustic waveform and the vibration waveform, respectively; calculating means for calculating an integrated value of a spectrum amplitude corresponding to a preset frequency band from the frequency spectrum; Means for outputting an alarm when the value exceeds a preset value is provided, thereby solving the above-mentioned problem. The invention according to claim 6 is a chattering detection device for a cold rolling mill, wherein an acoustic waveform observing means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, and a cold rolling mill or A vibration detecting means for detecting a vibration waveform of the auxiliary roll device between stands, a cross spectrum calculating means for calculating a cross spectrum of the acoustic waveform and the vibration waveform, and a cross corresponding to a preset frequency band from the cross spectrum. The present invention has also solved the above-described problem by including a calculating unit that calculates an integrated value of the spectrum amplitude and a unit that outputs an alarm when the cross-spectral integrated value exceeds a preset value. According to a seventh aspect of the present invention, in the chattering detection device for a cold rolling mill, an acoustic sensor which is set near the cold rolling mill and detects a sound during rolling of the material to be rolled and converts the sound into an electric signal. A band-pass filter that passes only components of a predetermined frequency band from the electric signal, an integration circuit that square-integrates the output of the band-pass filter over a predetermined time length, The above problem is also solved by providing a comparison circuit for outputting an alarm when the output exceeds a preset value.

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a configuration diagram illustrating a first embodiment of a chattering detection device for a cold rolling mill according to the present invention. In FIG. 3, 10 is a group of cold rolling mills, 11 is a rolling mill (rolling stand), 12 is an auxiliary roll device installed between the rolling stands, and 14 detects sound near the rear stand of the rolling mill. A microphone 16 which is an acoustic sensor for converting to an electric signal, a vibration sensor 18 for converting the vibration of the tension meter between rolling stands to an electric signal, 18 and 20
Are amplifier circuits for amplifying the acoustic and vibration waveforms converted into electric signals into voltage waveforms having amplitudes in appropriate ranges, respectively. A band-pass filter (BPF) that passes only a waveform component in a frequency band characteristic of chattering, and a rectifier circuit that calculates an effective value of an output waveform of each BPF for each unit time set in advance; 30 is a determination that an alarm signal is issued as a detection of occurrence of chattering when both effective values of frequency band components unique to chattering of the rectified acoustic waveform and vibration waveform as described above become greater than or equal to a set value. Circuit, 32
Is an alarm device that issues an alarm to a worker using a speaker or the like based on the output of the determination circuit 30. The microphone 1
As the four types, a general microphone having a sufficient sensitivity to convert sound in a frequency band of about 0 to 1000 Hz into an electric signal, including a frequency of 100 to 300 Hz which is said to be characteristic of chattering, preferably May be used as a condenser microphone, and the installation position may be generally near the outlet stand of a multi-stage cold rolling mill where chattering may occur. As the vibration sensor 16, a piezoelectric vibration pickup generally used for measuring mechanical vibration may be used.
Further, the installation place may be a mill frame, or if a roll such as a tension meter or an auxiliary roll device 12 is provided between stands, it may be installed on a frame supporting the roll. Amplifying circuits 18 and 2 of the microphone 14 and the vibration sensor 16
For 0, commercially available amplifiers corresponding to the respective sensors may be used. The BPFs 22 and 24 are each realized by using a known circuit element alone or a circuit, and use a frequency band of 100 to 300 Hz, which is generally known as a chattering frequency, as a pass band. Preferably, the natural frequency of the mill-strip system may be measured and set for the rolling stand in advance. The rectifier circuit 26, 2
Reference numeral 8 may be a peak hold circuit that outputs the maximum value of the amplitude within a preset time instead of the effective value calculation, and the time length that is the unit of integration or detection of the maximum value is It may be determined appropriately based on the target chattering detection response, but is preferably 0.5 seconds or less. The determination circuit 30 includes a rectifier circuit 2
It is determined whether or not the output of the acoustic waveform and the output of the vibration waveform output by 6, 28 exceed a set reference value. The reference value is preferably set by performing measurement in advance for each of the acoustic waveform and the vibration waveform for the rolling process in which chattering does not occur, but for each steel type and plate thickness of the material to be rolled, and for each speed during rolling. The set value may be changed. Next, the operation of the first embodiment will be described. The acoustic waveform detected by the microphone 14 during the cold rolling of the material 8 to be rolled and converted into an electric signal is amplified by the amplifier circuit 18 into a waveform having an appropriate range of amplitude, and is characteristic of chattering by the BPF 22. Only the frequency band is extracted, and the rectifier circuit 26
Is rectified as the output amplitude of the BPF 22. This acoustic waveform, the waveform after band-pass filtering by the BPF 22,
The first embodiment of the output amplitude after rectification by the rectification circuit 26 is as follows.
4 (a), (c) and (e) of FIG. or,
At the same time, the vibration waveform obtained by the vibration sensor 16 detecting the vibration of the material 8 to be rolled via the auxiliary roll device 12 between stands and converting the vibration into an electric signal is amplified by the amplifier circuit 20 into a waveform having an appropriate range of amplitude. After that, only the frequency band characteristic of chattering is extracted by the BPF 24 and rectified by the rectifier circuit 28 as the output amplitude of the BPF 24. 4 (b), (d), and (f) of FIG. 4 show the oscillation waveform, the waveform after band-pass filtering by the BPF 24, and the output amplitude after rectification by the rectifier circuit 28, respectively. The determination circuit 30 compares the effective values of the acoustic waveform component and the vibration waveform component that have been filtered and rectified as described above with the preset set values, respectively, and outputs both the acoustic waveform and the vibration waveform as the set values. Is exceeded, a chattering detection signal is output to the alarm device 32. (E) and (f) of FIG.
In FIG. 4, threshold values for the amplitudes of the acoustic waveform and the vibration waveform are indicated by broken lines, and the respective determination results are schematically shown in FIG.
This is illustrated in FIG. The output of the determination circuit 30 is obtained by taking the logical product of these (g) and (h) at each time (i) in FIG.
become that way. Further, in the first embodiment of FIG. 4, for the purpose of comparison with the related art, the alarm operation according to the present invention is not performed, and the worker detects chattering and takes an operation action by decelerating the line. The history of the rolling speed during the operation is as shown in FIG. 4 (j), and it can be seen that the present invention detects chattering occurring during the rolling process earlier than the conventional operator found. FIG. 5 shows the output of each part of the second embodiment in which the crane device passes above the line and generates noise during rolling of the material 8 to be rolled in the first embodiment. The waveforms at each stage in FIG. 5 correspond to those described in the first embodiment. As shown in this figure, only the acoustic waveform (a) and its band-pass filter output (c) could erroneously detect noise due to crane traffic as chattering, as shown in (g). As in the determination circuit output (i) in the example, erroneous detection can be eliminated. FIG. 6 shows the output of each part of the third embodiment in the case where the welding point in the material to be rolled has passed in the first embodiment. The waveforms at each stage in FIG. 6 correspond to those described in the first embodiment. As shown in this figure, impact vibration is applied to the auxiliary roll between stands when passing through the welding point, and such an impact waveform is a broadband waveform including a chattering frequency, which may be erroneously detected as chattering in the past. However, as in the present invention, erroneous detection could be eliminated by combining the determination with the acoustic waveform measured near the mill. FIG. 7 is a diagram showing the configuration of the second embodiment of the present invention. The cold rolling mill 10, the stand-to-stand auxiliary roll device 12, and the method of installing the microphone 14 and the vibration sensor 16 therewith may be the same as in the first embodiment, and a description thereof will be omitted. 7, reference numerals 18 and 20 denote amplification circuits for amplifying output waveforms of the microphone 14 and the vibration sensor 16 similar to those in the first embodiment. Reference numerals 42 and 44 denote frequency components of outputs of the amplification circuits 18 and 20. It is a frequency analysis circuit that calculates each. In the frequency analysis circuits 42 and 44, in order to increase the time sensitivity of chattering detection, it is necessary to set the waveform length of the frequency analysis to be short within an allowable error, and it is preferable to set the length to about 0.5 seconds. 46,
48 is an integrating circuit for integrating the intensity of the frequency components included in the frequency band unique to chattering from the outputs of the frequency analysis circuits 42 and 44, 50 is an acoustic waveform,
Comparison of the strength of the frequency component included in the frequency band unique to chattering calculated with respect to the vibration waveform with a preset set value, and determining that a chattering detection signal is output when both exceed the set value. Circuit
32 is an alarm device similar to that of the first embodiment. next,
The operation of the second embodiment will be described. During the cold rolling of the material to be rolled, the microphone 14 detects and converts the acoustic waveform converted into an electric signal, and the vibration sensor 16 detects the vibration of the material to be rolled through the auxiliary roll device 12 between the stands to generate an electric signal. The vibration waveforms converted into the signals are the same as those in the first embodiment, and the description is omitted. The acoustic waveform converted into the electric signal is amplified into a waveform having an appropriate range of amplitude by the amplifier circuit 18, converted into a data string of intensity (frequency component) for each frequency by the frequency analysis circuit 42, and then integrated. The circuit 46 outputs an integrated value of frequency components in a frequency band characteristic of chattering. At the same time, the vibration sensor 1
The vibration waveform detected and converted into an electrical signal by the amplifier 6 is amplified by the amplifier circuit 20 into a waveform having an appropriate range of amplitude, and is converted by the frequency analysis circuit 44 into a data string of intensity (frequency component) for each frequency. Thereafter, the integrating circuit 48 outputs the integrated value of the frequency components in the frequency band characteristic of chattering.
The determination circuit 50 compares the integrated values of the frequency components related to the chattering frequency band of the acoustic waveform and the vibration waveform calculated as described above with preset values, respectively, and outputs both the acoustic waveform and the vibration waveform. If the set value is exceeded, a chattering detection signal is output to the alarm device 32. FIG. 8 shows an example in which output waveforms of the integrating circuits 46 and 48 and the determining circuit 50 are recorded with respect to chattering generated during the rolling operation. The operating conditions are the same as in the first embodiment, but as can be seen from this figure, the chattering that occurred during the rolling process according to the present invention is detected earlier than the conventional operator found. FIG. 9 is a diagram showing the configuration of the third embodiment of the present invention. The cold rolling mill 10, the stand-to-stand auxiliary roll device 12, and the method of installing the microphone 14 and the vibration sensor 16 therewith may be the same as in the first embodiment, and a description thereof will be omitted. In FIG. 9, reference numeral 60 denotes a cross spectrum calculation circuit for calculating a cross spectrum of an acoustic waveform and a vibration waveform output from the amplification circuits 18 and 20 as in the first embodiment. 64 is an integrating circuit that integrates the cross spectrum intensity of the frequency band characteristic of chattering in the output of the integrating circuit 64. The integrating circuit 64 compares the output of the integrating circuit 62 with a preset set value, and calculates the integrated value. Is a determination circuit that outputs a chattering detection signal when it exceeds 32.
Is an alarm device similar to the first embodiment. Next, the operation of the third embodiment will be described. During the cold rolling of the material to be rolled, the microphone 14 detects the sound waveform, converts it to an electric signal, and further amplifies the acoustic waveform to an appropriate range of amplitude by the amplifier circuit 18. After detecting the vibration of the material to be rolled through the device 12 and converting it into an electric signal, the vibration waveform amplified by the amplifier circuit 18 to an appropriate range of amplitude is the same as in the first embodiment, and therefore will be described. Is omitted. Cross spectrum calculation circuit 60
Is described in, for example, "Signal Processing", co-authored by Iwao Morishita and Hidefumi Obata (Academic Society of Instrument and Control Engineers (1997), p. 121). The discrete Fourier transform of the subsequences x _r (n) and y _r (n) multiplied by the data window is X _r (k),
Assuming that Y _r (k), an operation described by the following equation is performed.

(Equation 1) Here, k is a variable corresponding to the frequency, and X ^* is a quantity X
Represents the complex conjugate of The integrating circuit 62 integrates and outputs the intensity of the frequency spectrum characteristic of chattering of the cross spectrum of the acoustic waveform and the vibration waveform calculated as described above. The determination circuit 64 compares the output of the integration circuit 62 with a preset set value, and outputs a chattering detection signal to the alarm device 32 when the output of the integration circuit 62 exceeds the set value. FIG. 10 shows an example in which output waveforms of the integrating circuit 62 and the determining circuit 64 are recorded with respect to chattering generated during the rolling operation. The operating conditions are the same as in the first embodiment, but as can be seen from this figure, the chattering that occurred during the rolling process according to the present invention is detected earlier than the conventional operator found. In the embodiment as described above, the alarm device 32 may turn on an indicator light, emit a warning sound with a speaker or the like, and alert the worker to reduce the line speed, or a sequencer or the like. May be used to automatically reduce the rolling speed. In the above-described embodiment, the band-pass filter, the frequency analysis circuit, the cross-spectrum calculation circuit, the integration circuit, and the determination circuit are digitally sampled at equal time intervals in accordance with a recent digitization method. It can be replaced by operation on signals, or can be configured by software on a microprocessor instead of those circuits. In the above-described embodiment, the acoustic sensor and the vibration sensor are used together. However, the chattering can be detected from the effective value of the output of only the acoustic sensor without the vibration sensor. In this case, it can be realized with a simple device configuration as compared with the method using a vibration sensor or a thickness gauge, and the sensor is separated from the mill body by using a non-contact detection means called an acoustic sensor. It can be installed and the maintainability of the sensor is improved.

As described above, according to the present invention,
Since both the acoustic waveform and the vibration waveform or the effective value of the acoustic waveform observed during the cold rolling operation of the material to be rolled, the characteristic waveform component of the chattering was extracted to detect the chattering occurrence. Workers can quickly take countermeasures during the cold rolling work to reduce chattering failures and prevent sheet breakage due to chattering vibration, which is very important in terms of production yield and operation efficiency. Has a great effect. In addition, noise caused by factors other than the rolling operation and impact-induced vibration applied to equipment having a rolling mill or an auxiliary roll between stands, which have been caused by the method of detecting chattering from an acoustic sensor or a vibration sensor that has been conventionally proposed. Therefore, it is possible to eliminate a production loss such as erroneously cutting off a normally rolled portion of a material to be rolled or erroneously decelerating during normal rolling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a prior art described as a first embodiment in JP-A-60-137512.

FIG. 2 is a block diagram showing a prior art which is also described as a second embodiment.

FIG. 3 is a configuration diagram showing a first embodiment of a chattering detection device for a cold rolling mill according to the present invention.

FIG. 4 is a diagram illustrating a first example in which detection waveforms of an acoustic sensor and a vibration sensor and output waveforms of a rectifier circuit and a determination circuit are recorded with respect to chattering generated during a rolling operation in the first embodiment.
Diagram showing the embodiment

FIG. 5 is a diagram showing a second embodiment in which the same output waveforms as those of FIG. 4 are recorded when the crane device passes above the line and generates noise in the first embodiment.

FIG. 6 is a third embodiment in which the same output waveforms as those of FIG. 4 are recorded when the welding point of the material to be rolled passes in the first embodiment.
Diagram showing the embodiment

FIG. 7 is a block diagram showing a waveform processing configuration of a second embodiment of the chattering detection device of the cold rolling mill according to the present invention.

FIG. 8 is a diagram showing an example of output waveforms of an integrating circuit and a determination circuit with respect to chattering generated during a rolling operation in the second embodiment.

FIG. 9 is a block diagram showing a configuration of a waveform processing of a third embodiment of the chattering detection device of the cold rolling mill according to the present invention.

FIG. 10 is a diagram illustrating an example of output waveforms of an integrating circuit and a determination circuit with respect to chattering generated during a rolling operation in a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 8 ... Rolled material 10 ... Cold rolling mill group 11 ... Rolling stand 12 ... Auxiliary roll device 14 ... Microphone 16 ... Vibration sensor 18 ... Acoustic waveform amplification circuit 20 ... Vibration waveform amplification circuit 22, 24 ... Bandpass filter (BPF) 26, 28 rectifier circuit 30, 50, 64 determination circuit 32 alarm device 42, 44 frequency analysis circuit 46, 48, 62 integration circuit 60 cross-spectrum calculation circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shozo Ogimoto 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside of the Chiba Works, Chiba Works (72) Inventor Tomohiro Kaneko 1 Kawasakicho, Chuo-ku, Chiba City, Chiba Prefecture Address Kawasaki Steel Corporation Chiba Works (72) Inventor Hidenori Miyake 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Kawasaki Steel Corporation Chiba Works F-term (reference) 2G064 AA01 AB00 AB07 AB08 AB13 BD18 BD20 CC02 CC30 CC31 CC33 CC42

Claims (7)

[Claims] In a cold rolling mill, during rolling of a material to be rolled,
In both the acoustic waveform observed in the vicinity of the cold rolling mill and the vibration waveform observed in the cold rolling mill or the auxiliary roll device between stands, the waveform component unique to chatter exceeded the set reference value. A chattering detection method for a cold rolling mill, wherein the occurrence of chattering is detected in such a case. 2. The process of rolling a material to be rolled in a cold rolling mill,
The acoustic waveform observed in the vicinity of the cold rolling mill is converted into an electric signal, a component of a frequency band characteristic of chattering is extracted from the electric signal, and when its effective intensity is equal to or more than a set value, A method for detecting chattering in a cold rolling mill, wherein occurrence of chattering is detected. 3. A band-pass filter having a predetermined bandwidth in order to extract a component of a frequency band characteristic of chattering from the electric signal. Chattering detection method for cold rolling mill. 4. An acoustic waveform observation means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, and a vibration detecting means for detecting a vibration waveform of the cold rolling mill or an auxiliary roll device between stands thereof. And a band-pass filter that passes only components of a predetermined frequency band of the acoustic waveform and the vibration waveform, respectively, and an amplitude of the band-pass filter output of the acoustic waveform and the vibration waveform exceeds a preset value, respectively. Means for outputting an alarm in a case, the chattering detecting device for a cold rolling mill. 5. An acoustic waveform observation means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, and a vibration detecting means for detecting a vibration waveform of the cold rolling mill or an auxiliary roll device between stands thereof. Frequency characteristic calculating means for calculating the frequency spectrum of the acoustic waveform and the vibration waveform, respectively; calculating means for calculating an integrated value of the spectrum amplitude corresponding to a preset frequency band from the frequency spectrum, Means for outputting an alarm when the spectrum integrated value exceeds a preset value, respectively; and a chattering detection device for a cold rolling mill. 6. An acoustic waveform observation means for observing the sound during rolling of the material to be rolled in the vicinity of the cold rolling mill, and a vibration detecting means for detecting a vibration waveform of the cold rolling mill or an auxiliary roll device between stands thereof. Cross-spectrum calculating means for calculating a cross spectrum of the acoustic waveform and the vibration waveform; calculating means for calculating an integrated value of a cross-spectrum amplitude corresponding to a preset frequency band from the cross spectrum; Means for outputting an alarm when the integrated value exceeds a preset value; and a chattering detection device for a cold rolling mill. 7. An acoustic sensor which is set near a cold rolling mill and detects a sound during rolling of a material to be rolled and converts the sound into an electric signal. A band-pass filter that passes the signal; an integration circuit that square-integrates the output of the band-pass filter over a predetermined time length; and an alarm when the output of the integration circuit exceeds a predetermined value. A chattering detection device for a cold rolling mill, comprising: a comparison circuit that outputs a signal;