JP2007253252A - Grinding mark determining method and grinding device for rolling roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding mark determining method for determining whether a grinding mark is generated. <P>SOLUTION: A rotation of a grindstone 3 is detected as a rotation signal A, and vibration of a rolling roll 2 is detected as a vibration signal B, followed by extracting a plurality of vibration waveforms Y of the rolling roll 2 per rotation of the grindstone 3, from the detected rotation signal A and the detected vibration signal B. Then the extracted vibration waveforms Y are averaged at every n waveforms in chronological order to prepare a plurality of average vibration waveforms Z, and the correlation between the prepared average vibration waveforms Z is obtained, thereby to determine whether the grinding mark attributable to the grindstone 3 is generated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a grinding mark determination method and a rolling roll grinding apparatus.

Conventionally, a rolled material is introduced into a rolling apparatus having a rolling roll such as a work roll or a backup roll, and the rolled material is rolled to a predetermined thickness by the rolling roll. Since the surface of the rolling roll is worn and the surface accuracy is lowered when the rolling roll is continuously used, a grinding operation for periodically grinding the surface of the rolling roll with a grindstone of a grinding apparatus is performed.
During grinding operations, chatter vibration may occur due to improperness such as the rotation speed of the rolling roll, the feeding speed of the grinding wheel, or the rotation speed of the grinding wheel, or defective grinding wheels. The chatter vibration causes grinding on the surface of the rolling roll. An uneven grinding mark may be formed.

It is said that chatter vibration is mainly caused by forced vibration generated by rotation of a rolling roll or a grindstone or self-excited vibration generated by an internal force generated by a grinding action.
If a grinding mark is formed on the surface of the rolling roll, when the rolled material is rolled with the rolling roll, the grinding mark is transferred to the surface of the rolling material, and the quality of the rolled material is deteriorated. .

Thus, a number of techniques for detecting chatter vibration that is considered to be the cause of the formation of grinding marks during grinding operations have been developed, and are disclosed in, for example, Patent Documents 1 and 2.
In the grinding device of Patent Document 1, vibrations of a cradle and a grindstone that receive rolling rolls are measured, a vibration frequency distribution indicating a relationship between the vibration level and the frequency is obtained, and whether or not chatter vibration is generated based on the vibration frequency distribution. Is judged.

In the chatter detection vibration method of Patent Document 2, the vibration of the grinding apparatus is measured, the vibration is frequency-converted, a relationship between a predetermined frequency and an amplitude is obtained in advance, and based on the magnitude and change of the amplitude at each frequency. The presence or absence of chatter vibration is judged.
JP-A-11-77532 JP 2000-233368 A

However, the vibration of the grinding device includes various vibrations including harmonic components such as vibration due to rotation of the rolling roll, vibration due to bearings supporting the rolling roll, vibration due to rotation of the grinding wheel, and so on. It has been raised from the field that it is difficult to discriminate only chatter vibration directly corresponding to a grinding mark from various vibrations.
Moreover, it has been raised from the field that grinding marks are formed on the surface of the rolling roll, although chatter vibration is hardly observed. In this case, with the techniques of Patent Documents 1 and 2, it is very difficult to completely determine whether or not a grinding mark is generated from chatter vibration. In particular, chatter vibrations caused by defects in the grindstone (eccentricity, waviness, partial protrusion of abrasive grains) are not observed, and even in such a case, a grinding mark may be formed.

  Then, an object of this invention is to provide the determination method of the grinding mark which can determine easily the presence or absence of generation | occurrence | production of a grinding mark, and the grinding apparatus of a rolling roll in view of the said problem.

In order to achieve the above object, the present invention has taken the following measures.
That is, the technical means for solving the problem in the present invention is to determine the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll equipped with a grindstone. A method for determining a grinding mark to be performed, wherein the rotation of the grindstone is taken out as a rotation signal, the vibration of the rolling roll is taken out as a vibration signal, and the grindstone is rotated every rotation of the grindstone from the taken out rotation signal and vibration signal. A plurality of rolling roll vibration waveforms are extracted, and the extracted vibration waveforms are averaged every n pieces in time series to create a plurality of average vibration waveforms, and grinding marks are generated based on the created average vibration waveforms. The point is to determine whether or not.

  The inventor verified the cause of the formation of grinding marks on the surface of the rolling roll from various angles during the grinding operation. Among them, for example, when the rolling roll is ground with a defective grindstone, the inventor considered that some vibration that is synchronized with the rotation cycle of the grindstone appears on the rolling roll side. Further, the inventor thinks that, for example, even when the grindstone is rotating while being eccentric, the grindstone has a poor contact with the rolling roll, and periodic vibrations resulting from the contact appear on the rolling roll side. It was.

It is considered that such a situation mainly appears as a change in the periodic contact state between the grinding wheel and the rolling roll, in other words, the load fluctuation of the grinding wheel with respect to the rolling roll appears as a vibration synchronized with the rotation of the grinding wheel. As a result, it was inferred that a grinding mark was generated when such load fluctuation occurred.
Therefore, the inventor does not look only at chatter vibration during the grinding operation as in the prior art, but whether or not the rolling roll vibration is generated in conjunction with the rotation of the grinding wheel (periodic load of the grinding wheel relative to the rolling roll). Whether or not grinding marks have occurred is determined by seeing whether there is any fluctuation.

Specifically, the vibration waveform is extracted for each rotation of the grindstone from the measured vibration of the rolling roll, and the presence / absence of the grinding mark is determined by observing the change of the vibration waveform in time series. .
Specifically, according to the method for judging a grinding mark in the present invention, the rotation of the grindstone is taken out as a rotation signal, the vibration of the rolling roll is taken out as a vibration signal, and the grinding wheel 1 is extracted from the rotation signal and the vibration signal taken out. A plurality of rolling roll vibration waveforms for each rotation are extracted.

  Then, by averaging the extracted vibration waveforms every n in time series, vibration components that are not synchronized with the rotation of the grindstone are removed, and an average vibration waveform that emphasizes the vibration components that are synchronized with the rotation of the grindstone is created. . By looking at a plurality of average vibration waveforms, it is possible to know whether or not the load on the rolling roll fluctuates periodically, thereby determining whether or not a grinding mark is generated.

When the correlation between the average vibration waveforms is high, it can be determined that a grinding mark has occurred because the load on the rolling roll is periodically changing, and when the correlation is low, the load on the rolling roll is not changing, It can be determined that no grinding mark is generated.
Another technical means in the present invention is to determine a grinding mark for determining the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll provided with a grindstone. In this method, the rotation of the grindstone is taken out as a rotation signal, the vibration of the rolling roll is taken out as a vibration signal, and the vibration waveform of the rolling roll for each rotation of the grindstone is extracted from the extracted rotation signal and vibration signal. And a plurality of reference waveforms indicating one rotation of the grindstone, and the coherence between each reference waveform and the vibration waveform for every n pieces is obtained using Equation (1), and generation of a grinding mark is generated based on this coherence. The point is to determine the presence or absence.

In the grinding mark determination method described above, the vibrations of the rolling roll for each rotation of the grindstone are summarized in time series to obtain an average vibration waveform, and the presence or absence of the grinding mark is determined by looking at each average vibration waveform. .
Instead, the coherence of each reference waveform and vibration waveform for every n pieces using the reference waveform indicating one rotation of the grindstone, the vibration waveform of the rolling roll for each rotation of the grindstone, and Equation (1). And whether or not a grinding mark is generated is determined based on the coherence.

  By obtaining the coherence between the reference waveform and the vibration waveform, vibration having a high correlation with the rotation of the grindstone can be found for each frequency band during the grinding operation. And, it is possible to specify in advance the frequency range with high responsiveness to the presence or absence of the grinding mark, and to determine the presence or absence of the grinding mark from the level of coherence in the specific frequency range during the grinding operation It becomes.

  Another technical means in the present invention is to determine a grinding mark for determining the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll provided with a grindstone. In this method, the rotation of the grindstone is taken out as a rotation signal, the vibration of the rolling roll is taken out as a vibration signal, and a plurality of rolling roll vibration waveforms for each rotation of the grindstone are extracted from the rotation signal and the vibration signal. Then, the coherence of the vibration waveform for every n pieces with respect to the rotation of the grindstone is obtained using the equation (2), and the presence or absence of the occurrence of the grinding mark is determined based on this coherence.

The inventor has determined that the rotation of the grindstone is generally substantially constant when obtaining the coherence between the reference waveform and the vibration waveform. That is, when the rotation of the grindstone is constant, S _xx in Equation (1) is 1, and S _Xy is the spectrum of the vibration waveform. Therefore, when these S _xx and S _xy are substituted into Equation (1), Equation (1) 2).
Therefore, the coherence of the vibration waveform for every n pieces with respect to the rotation of the grindstone can be obtained by the equation (2). When the coherence obtained by the equation (2) is used, the grinding mark The presence or absence of occurrence can be determined.

  Another technical means for solving the problems in the present invention is a rolling roll grinding apparatus provided with a rotatable grindstone, a rotation detecting unit for detecting rotation of the grindstone and outputting it as a rotation signal, and the rolling roll A vibration detection unit that detects a vibration of the grinding wheel and outputs the vibration signal as a vibration signal, a synchronous waveform extraction unit that extracts a plurality of vibration waveforms of the rolling roll for each rotation of the grindstone from the rotation signal and the vibration signal, and the synchronous waveform extraction The average vibration waveform generation unit that averages every n vibration waveforms extracted by the unit to create a plurality of average vibration waveforms, and the correlation between the average vibration waveforms generated by the average vibration waveform generation unit And a correlation calculation unit for obtaining the correlation.

The grinding mark determination method of the present invention is applied as an apparatus, and the correlation calculation unit obtains the correlation between the average vibration waveforms to determine whether or not the grinding mark is generated.
Another technical means for solving the problems in the present invention is a rolling roll grinding apparatus provided with a rotatable grindstone, a rotation detecting unit for detecting rotation of the grindstone and outputting it as a rotation signal, and the rolling roll A vibration detection unit that detects the vibration of the grinding wheel and outputs it as a vibration signal, and extracts a plurality of vibration waveforms of the rolling roll and a reference waveform indicating one rotation of the grindstone from the rotation signal and the vibration signal. And a coherence calculation unit that obtains coherence from the vibration waveform every n.

The grinding mark determination method of the present invention is applied as an apparatus, and the presence or absence of a grinding mark can be determined by obtaining coherence by a coherence calculation unit.
It is preferable to include a display unit that displays the correlation calculated by the correlation calculation unit or the coherence calculated by the coherence calculation unit.
According to this, an operator or the like who performs grinding work can determine whether or not a grinding mark is generated from the correlation or coherence change displayed on the display unit.

A determination unit that determines the presence or absence of a grinding mark based on the correlation calculated by the correlation calculation unit or the coherence calculated by the coherence calculation unit, and that the determination unit determines that a grinding mark is generated It is preferable to provide an alarm part for informing.
According to this, when the grinding mark is formed on the rolling roll during the grinding operation, it can be notified by the alarm unit.

  According to the present invention, the presence or absence of a grinding mark can be easily determined.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 shows a grinding apparatus according to a first embodiment of the present invention. The grinding apparatus 1 grinds a rolling roll 2 of a rolling apparatus for rolling a rolled material, and includes a grindstone 3 for polishing the rolling roll 2 and a receiving base 4 for receiving the rolling roll 2.

The cradle 4 includes a pair of bearings 5 that rotatably support the rotating shaft of the rolling roll 2, and a roll drive motor 6 that applies rotational power to the rotating shaft of the rolling roll 2 is provided on one side of the bearing 5. Is arranged. The grindstone 3 is formed in a circular shape (circular base shape) and is freely rotatable by a grindstone drive motor 7.
Therefore, in the grinding device 1, the rolling roll 2 is rotated by the roll drive motor 6, the grindstone 3 is rotated, and the surface of the rolled grindstone 3 is brought into contact with the surface of the rolling roll 2, thereby bringing the surface of the rolling roll 2 into contact. Can be polished.

  The grinding apparatus 1 includes a rotation detection unit 10 that detects the rotation of the grindstone 3 and a vibration detection unit 11 that detects the vibration of the rolling roll 2. The rotation detection unit 10 is constituted by, for example, a rotary encoder. As shown in FIG. 3A, the rotation detection unit 10 outputs one pulse signal for each rotation of the grindstone 3, that is, for each rotation of the drive motor. Output as. In FIG. 3A, the grinding wheel 3 is rotated once between the H levels in the rotation signal A.

The vibration detection unit 11 is configured by a non-contact vibration sensor such as a vibration accelerometer, a velocity eddy current displacement meter, a laser displacement meter, and the magnitude of vibration of the rolling roll 2 as shown in FIG. Is output as a vibration signal B.
The grinding device 1 includes a synchronous waveform extraction unit 12 that extracts a plurality of vibration waveforms Y of the rolling roll 2 for each rotation of the grindstone 3 from the rotation signal A and the vibration signal B. Specifically, the synchronization waveform extraction unit 12 is configured by a computer or the like to which the rotation signal A and the vibration signal B amplified by the amplifier unit 13 are input. The synchronization waveform extraction unit 12 individually stores the vibration waveform Y of the vibration signal B in the H level section each time a signal (H level) indicating one rotation is input in the rotation signal A.

For example, as shown in FIG. 3, if the grindstone 3 has rotated 10 times, the synchronization waveform extraction unit 12 will extract 10 vibration waveforms Y for each rotation of the grindstone 3 in time series.
The grinding apparatus 1 has an average vibration waveform generation unit 14 that averages every n vibration waveforms Y extracted by the synchronous waveform extraction unit 12 to create a plurality of average vibration waveforms Z. The average vibration waveform generation unit 14 is configured by a computer or the like to which a signal corresponding to the vibration waveform Y is input.

For example, as illustrated in FIG. 3, the average vibration waveform generation unit 14 performs n rotations (for example, n
= 10) The n vibration waveforms Y extracted by (10) are respectively added, and one average vibration waveform Z is created from the n vibration waveforms Y and stored.
When creating one average vibration waveform Z from n vibration waveforms Y, the average vibration waveform generating unit 14 adds them after aligning the beginning and end of each vibration waveform Y. The average vibration waveform generation unit 14 stores the average vibration waveform Z every time n vibration waveforms Y are extracted by the synchronous waveform extraction unit 12.

  Usually, since various vibrations are combined with the vibration waveform Y, it is not possible to easily determine whether or not the vibration waveform Y is synchronized with the rotation of the grindstone 3 even if the vibration waveform Y is directly viewed. In addition, since the n vibration waveforms Y are added by the average vibration waveform generation unit 14, the component that is not synchronized with the rotation of the grindstone 3 is canceled, and the component that is synchronized with the rotation of the grindstone 3 is easily emphasized.

The grinding device 1 has a display unit 16 for displaying an average vibration waveform Z. The display unit 16 is composed of a monitor connected to a computer. An average vibration waveform Z as shown in FIG. 4 is displayed on the display unit 16 during the grinding operation.
When the average vibration waveform Z displayed on the display unit 16 is the waveform shown in FIG. 4A, the average vibration waveforms Z are similar to each other, and therefore, the correlation between the average vibration waveforms Z is high. Thus, when the average vibration waveform Z with high correlation is continuously displayed on the display unit 16, the load of the grindstone 3 on the rolling roll 2 fluctuates periodically, and this periodic load fluctuation is the average vibration. It is considered that periodic vibrations appear in the vibration waveform Y that is the source of the waveform Z.

Therefore, when a waveform having a high correlation of the average vibration waveform Z is continuously displayed on the display unit 16, the load of the grindstone 3 fluctuates with respect to the rolling roll 2, and at this time, a grinding mark is generated. It can be judged that.
When the average vibration waveform Z displayed on the display unit 16 is shown in FIG. 4B, the average vibration waveform Z is not similar to each other, and therefore it can be determined that the correlation of the average vibration waveform Z is low. Thus, when the average vibration waveform Z having low correlation is continuously displayed on the display unit 16, it can be determined that there is almost no load fluctuation of the grindstone 3 and no grinding mark is generated.

Therefore, according to the grinding device 1 of the present invention, the operator operating the grinding device 1 sees the vibration waveform Y displayed on the display unit 16 and the similarity of each average vibration waveform Z displayed on the display unit 16. Whether or not a grinding mark is generated can be determined by determining the property.
Note that the operator or the like looks at the vibration waveform Y displayed on the display unit 16 to determine whether or not a grinding mark has occurred. Instead of the display unit 16, as shown in FIG. In addition, a correlation calculation unit 15 for calculating the correlation of each average vibration waveform Z is provided, and a value obtained by the correlation calculation unit 15 is displayed on the display unit 16 to generate a grinding mark from the value indicating the correlation. You may determine the presence or absence of.

Specifically, the correlation calculation unit 15 calculates the autocorrelation of the average vibration waveform Z and displays the autocorrelation value on the display unit 16, indicating that the autocorrelation value is large (close to 1) and high in correlation. If it is determined that a grinding mark is generated, and if the autocorrelation value is small (close to 0) and indicates a low correlation, it can be determined that no grinding mark is generated.
Moreover, it is preferable to provide the grinding | polishing apparatus 1 with the determination part 17 which determines the presence or absence of a grinding mark. Specifically, for example, after allowing the data of the average vibration waveform Z shown in FIG. 4 to be input to the determination unit 17, the determination unit 17 uses the image processing or the like to input the average vibration waveforms Z to each other. The similarity can be obtained, and the determination unit 17 determines that a grinding mark is generated when the similarity of the average vibration waveform Z is high, and when the similarity of the average vibration waveform Z is low, It is better to be able to judge automatically that there is no occurrence.

In addition, the autocorrelation value calculated by the correlation calculation unit 15 can be input to the determination unit 17, and a grinding mark is generated when the input autocorrelation value exceeds the threshold value. It may be determined that no grinding mark is generated when the threshold value is not exceeded.
Further, in addition to the determination unit 17, it is preferable to provide an alarm unit 18 for notifying that the determination unit 17 has determined that a grinding mark has occurred. The alarm unit 18 can be composed of a lamp and a speaker. The correlation calculation unit 15 and the determination unit 17 can be realized by a computer or a computer program.

Next, a method for determining a grinding mark will be described with reference to FIG.
The rotation of the grindstone 3 is taken out as a rotation signal A, and the vibration of the rolling roll 2 is taken out as a vibration signal B (S1). Specifically, the rotation signal A of the grindstone 3 is extracted using the rotation detection unit 10 of the grinding apparatus 1, and the vibration signal B is extracted using the vibration detection unit 11 of the grinding apparatus 1.
Next, a plurality of vibration waveforms Y of the rolling roll 2 for each rotation of the grindstone 3 are extracted from the rotation signal A and the vibration signal B (S2). Specifically, the vibration waveform Y for each rotation of the grindstone 31 is extracted using the synchronous waveform extraction unit 12 of the grinding apparatus 1.

A plurality of average vibration waveforms Z are created by averaging the extracted vibration waveforms Y every n pieces in time series (S3). Specifically, an average vibration waveform Z is created by averaging the ten vibration waveforms Y using the average vibration waveform generation unit 14 of the grinding apparatus 1.
The correlation between the average vibration waveforms Z is obtained (S4), and the presence or absence of occurrence of a grinding mark is determined (S5). Specifically, the average vibration waveform Z is sequentially displayed on the display unit 16 of the grinding apparatus 1. Then, as described above, when the operator sees the displayed average vibration waveform Z and the displayed average vibration waveforms Z are similar to each other, it is determined that the grinding mark is formed on the surface of the rolling roll 2. When the average vibration waveform Z is not similar, it is determined that the grinding mark is not formed on the surface of the rolling roll 2.
[Second Embodiment]
FIG. 5 shows a grinding apparatus 1 according to a second embodiment of the present invention. In the second embodiment, portions having the same configuration and function as those of the grinding device 1 of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  This grinding apparatus 1 is a synchronous waveform extraction unit that extracts a plurality of vibration waveforms Y of the rolling roll 2 and reference waveforms X indicating one rotation of the grindstone 3 from the rotation signal A and the vibration signal B every rotation of the grindstone 3. 20. The synchronization waveform extraction unit 20 is configured by a computer or the like to which the rotation signal A and the vibration signal B amplified by the amplifier unit 13 are input. The synchronization waveform extraction unit 20 receives a signal (for example, a pulse signal) from the start of one rotation to the end of one rotation every time a signal (H level) indicating one rotation is input in the rotation signal A. And the vibration signal B from the start of one rotation to the end of one rotation is individually stored as the vibration waveform Y.

Further, the grinding apparatus 1 includes a coherence calculation unit 21 that obtains coherence using the vibration waveform Y every n pieces. The coherence calculation unit 21 is realized by a computer, a program incorporated in the computer, or the like.
The coherence calculation unit 21 includes a spectrum calculation unit 22 that calculates a spectrum using the reference waveform X and the vibration waveform Y, and a coherence calculation unit 23 that calculates a coherence based on the calculation result of the spectrum calculation unit 22. is doing.

Specifically, the spectrum calculation unit 22 performs FFT processing on the rotation signal A for each rotation corresponding to the reference waveform X, calculates the power spectrum S _xx in the reference waveform X by squaring the value, and The vibration signal B for each rotation corresponding to the vibration waveform Y is subjected to FFT processing, and the value is squared to calculate the power spectrum S _yy in the vibration waveform Y. The spectrum calculation unit 22 performs FFT processing on the rotation signal A and the vibration signal B and multiplies the FFT-processed reference waveform X and the vibration waveform Y to obtain a cross spectrum S _{xy of} both.

The coherence calculation unit 23 performs coherence calculation using the calculation result in the spectrum calculation unit 22. Specifically, the coherence calculation unit 21 incorporates a calculation formula represented by Expression (1) as a program, and every n pieces using the power spectra S _xx , S _yy , S _xy , and Expression (1). The coherence between each reference waveform X and vibration waveform Y is obtained. Note that the symbol “C” in Equation (1) is coherence.

FIG. 8 shows the result of analysis of vibration data during grinding work on a rolling roll in which a large grinding mark was observed after grinding. The coherence between the reference waveform X and the vibration waveform Y was calculated, and this coherence was calculated from a frequency of 200 Hz. This is a summary of the results of calculating the level of coherence in each frequency band for each time lapse divided into 700 Hz every 100 Hz.
As shown in FIG. 8, when the coherence is large in the frequency bands of 400 Hz to 500 Hz and 500 Hz to 600 Hz and the grinding mark is generated, the vibration synchronized with the rotation of the grindstone 3 appears best in the above band. I understand.

Accordingly, during the grinding operation, it is possible to determine whether or not the grinding mark is generated from the coherence by looking at the frequency band closely related to the generation of the grinding mark, that is, the coherence of 400 Hz to 600 Hz. Become.
FIG. 9 shows the relationship between the size of the grinding mark in the above-described frequency band, which is closely related to the occurrence of the grinding mark, and the coherence. In FIG. 9, when the grinding mark is large, the coherence periodically changes and the coherence is also large.

As shown in FIG. 9, for example, when the coherence value is 0.4 or more (threshold or more), it can be determined that a grinding mark has occurred, and the coherence changes periodically. It can also be determined that a grinding mark has occurred.
Specifically, a graph as shown in FIG. 9 showing the change in coherence is displayed using the display unit 16, and the presence or absence of occurrence of a grinding mark is determined by an operator or the like viewing the change in coherence displayed on the display unit 16. be able to.

  In the second embodiment, similarly to the first embodiment, instead of the display unit 16, the determination unit 17 a is provided in the grinding device 1, and a threshold value used for the determination is set in the determination unit 17 a, Whether or not a grinding mark is generated may be determined based on whether or not the coherence exceeds a threshold value. When the determination unit 17a determines that the grinding mark is generated, the alarm unit 18b can notify the generation of the grinding mark.

Next, a method for determining a grinding mark will be described with reference to FIG.
The rotation of the grindstone 3 is taken out as a rotation signal A, and the vibration of the rolling roll 2 is taken out as a vibration signal B (S10). Specifically, the rotation signal A of the grindstone 3 is extracted using the rotation detection unit 10 of the grinding apparatus 1, and the vibration signal B is extracted using the vibration detection unit 11 of the grinding apparatus 1.

Next, a plurality of reference waveforms X indicating one rotation of the grindstone 3 and vibration waveforms Y of the rolling roll 2 for each rotation of the grindstone 3 are extracted from the rotation signal A and the vibration signal B (S11). Specifically, the reference waveform X and the vibration waveform Y for each rotation of the grindstone 31 are extracted using the synchronous waveform extraction unit 20 of the grinding apparatus 1.
Using the equation (1), the coherence between each reference waveform X and the vibration waveform Y is obtained every n (for example, n = 10) (S12). Specifically, the reference waveform X and the vibration waveform Y for each rotation of the grindstone 31 are extracted using the synchronous waveform extraction unit 20 of the grinding apparatus 1. The coherence between each reference waveform X and the vibration waveform Y is obtained using Equation (1) incorporated in the coherence calculation unit 21.

Whether or not a grinding mark is generated is determined based on the coherence (S13). Specifically, as described above, a frequency range having high responsiveness to the presence or absence of occurrence of a grinding mark is specified in advance (for example, 400 Hz to 600 Hz), and the grinding mark is determined from the magnitude of coherence at the specified frequency. Determine if it occurs.
[Third Embodiment]
FIG. 7 shows a grinding mark determination method according to the third embodiment of the present invention. An apparatus that implements the grinding mark determination method according to the third embodiment is realized by changing the coherence calculation unit 21 of the grinding apparatus 1 according to the second embodiment.

First, the grinding device 1 in which the coherence calculation unit 21 of the grinding device 1 shown in the second embodiment is changed will be described. The coherence calculation unit 21 includes a spectrum calculation unit 22 and a coherence calculation unit 23 as in the second embodiment.
Specifically, the spectrum calculation unit 22 calculates the power spectrum S _yy in the vibration waveform Y by performing FFT processing on the vibration signal B for each rotation corresponding to the vibration waveform Y and squaring the value. In this embodiment, the rotational speed of the grindstone 3 is always considered to be constant, and the spectrum S _xx in the reference waveform X is 1 + 0j (j is an imaginary unit), and the power spectrum S _xx in the reference waveform X is 1. . Further, since the spectrum S _xx in the reference waveform X is 1 + 0j, the cross spectrum S _xy between the reference waveform X and the vibration waveform Y becomes the spectrum S _y of the vibration waveform Y.

  Therefore, in this coherence calculation unit 23, a calculation formula represented by the formula (2) in which the rotational speed of the grindstone 3 is always considered to be constant is incorporated as a program, and the coherence calculation unit 23 uses the formula (2) to calculate n The coherence between each reference waveform X and vibration waveform Y is obtained for each piece. Note that the symbol “C” in Equation (2) is coherence.

Next, a method for determining a grinding mark will be described with reference to FIG.
The rotation of the grindstone 3 is taken out as a rotation signal A, and the vibration of the rolling roll 2 is taken out as a vibration signal B (S20).
Next, a plurality of vibration waveforms Y of the rolling roll 2 for each rotation of the grindstone 3 are extracted from the rotation signal A and the vibration signal B (S21). Specifically, only the vibration waveform Y for each rotation of the grindstone 31 is extracted using the synchronous waveform extraction unit 20 of the grinding apparatus 1. Using the equation (2), the coherence of the vibration waveform Y every n pieces is obtained (S22). Then, it is determined whether or not a grinding mark is generated based on the coherence (S23). Note that the method in S23 of FIG. 7 is the same as the determination method in the second embodiment.

It is a schematic block diagram of the grinding device in 1st Embodiment. It is a flowchart figure of the determination method of the grinding mark in 1st Embodiment. It is a figure which shows the reference | standard waveform X and the vibration waveform Y. FIG. 6 is a diagram showing the correlation at a plurality of average vibration waveforms Z. It is a schematic block diagram of the grinding device in 2nd Embodiment. It is a flowchart figure of the determination method of the grinding mark in 2nd Embodiment. It is a flowchart figure of the determination method of the grinding mark in 3rd Embodiment. It is a figure which shows coherence. It is a figure which shows the relationship between a coherence and a grinding mark. It is a schematic block diagram which shows the modification of a grinding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grinding device 2 Roll 3 Grinding wheel A Rotation signal B Vibration signal X Reference waveform Y Vibration waveform Z Average vibration waveform

Claims (10)

A grinding mark determination method for determining the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll provided with a grindstone,
While taking out the rotation of the grinding wheel as a rotation signal (A), taking out the vibration of the rolling roll as a vibration signal (B),
Extracting a plurality of vibration waveforms (Y) of the rolling roll for each rotation of the grindstone from the extracted rotation signal (A) and vibration signal (B),
A plurality of average vibration waveforms (Z) are created by averaging the extracted vibration waveforms (Y) every n pieces in time series,
A method for determining a grinding mark, wherein the presence or absence of a grinding mark is determined based on the created average vibration waveform (Z).   The correlation between the average vibration waveforms (Z) is obtained. When the correlation between the average vibration waveforms (Z) is high, it is determined that a grinding mark is generated, and when the correlation is low, it is determined that no grinding mark is generated. The method for determining a grinding mark according to claim 1. A grinding mark determination method for determining the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll provided with a grindstone,
While taking out the rotation of the grinding wheel as a rotation signal (A), taking out the vibration of the rolling roll as a vibration signal (B),
A plurality of vibration waveforms (Y) of the rolling roll for each rotation of the grindstone and a reference waveform (X) indicating one rotation of the grindstone are extracted from the extracted rotation signal (A) and vibration signal (B). ,
A method for determining a grinding mark, which determines the coherence between each reference waveform (X) and the vibration waveform (Y) for each n using Equation (1) and determines whether or not a grinding mark is generated based on this coherence.

A grinding mark determination method for determining the presence or absence of a grinding mark formed on the surface of the rolling roll when grinding the surface of the rolling roll with a grinding apparatus for the rolling roll provided with a grindstone,
While taking out the rotation of the grinding wheel as a rotation signal (A), taking out the vibration of the rolling roll as a vibration signal (B),
Extracting a plurality of vibration waveforms (Y) of the rolling roll per rotation of the grindstone from the rotation signal (A) and vibration signal (B),
A method of determining a grinding mark, wherein the coherence of every n vibration waveforms (Y) with respect to the rotation of the grindstone is obtained using equation (2), and whether or not a grinding mark is generated is determined based on this coherence.

  The grinding mark according to claim 3 or 4, wherein a frequency range having high responsiveness to the presence or absence of the grinding mark is specified in advance, and the presence or absence of the grinding mark is determined from the level of coherence at the specified frequency. Judgment method. In a grinding machine for rolling rolls equipped with a rotatable grindstone,
A rotation detector that detects rotation of the grindstone and outputs it as a rotation signal (A);
A vibration detector that detects vibration of the rolling roll and outputs it as a vibration signal (B);
A synchronous waveform extraction unit that extracts a plurality of vibration waveforms (Y) of the rolling roll for each rotation of the grindstone from the rotation signal (A) and the vibration signal (B);
Grinding a rolling roll, comprising an average vibration waveform generation unit that averages every n vibration waveforms (Y) extracted by the synchronous waveform extraction unit to create a plurality of average vibration waveforms (Z) apparatus. In a grinding machine for rolling rolls equipped with a rotatable grindstone,
A rotation detector that detects rotation of the grindstone and outputs it as a rotation signal (A);
A vibration detector that detects vibration of the rolling roll and outputs it as a vibration signal (B);
A synchronous waveform extraction unit that extracts a plurality of vibration waveforms (Y) of the rolling roll for each rotation of the grindstone and a reference waveform (X) indicating one rotation of the grindstone from the rotation signal (A) and the vibration signal (B). When,
A rolling roll grinding apparatus comprising: a coherence calculating unit that obtains coherence using vibration waveforms (Y) for every n pieces.   The grinding apparatus for a rolling roll according to claim 6, further comprising: a correlation calculation unit that obtains a correlation between the average vibration waveforms (Z).   The display device displays at least one of the average vibration waveform (Z), the correlation calculated by the correlation calculation unit, and the coherence calculated by the coherence calculation unit. The rolling roll grinding apparatus according to any one of the above.   A determination unit for determining the presence or absence of a grinding mark using any one of the average vibration waveform (Z), the correlation calculated by the correlation calculation unit, and the coherence calculated by the coherence calculation unit; The rolling roll grinding apparatus according to claim 6, further comprising an alarm unit that notifies that it has been determined that the occurrence of the occurrence of the rolling.

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