Wear state evaluation method for roll, operation method, wear state evaluation device for roll, operation device, and rolling apparatus

Abstract

This wear state evaluation method for a roll includes: a vibration data acquisition step for acquiring, for each of a plurality of portions of one or more metal plates, vibration data indicating the vibration of a roll over a plurality of number of rotations of the roll while changing a rotation speed of the roll rotating while making contact with the metal plate or another roll; an index acquisition step for acquiring, from the vibration data and for each of the plurality of portions, an index that uses a vibration amplitude at a frequency corresponding to a number of corners N of the roll for every number of rotations of the roll, for each of a plurality of numbers of corners Ns of the roll; and an evaluation step for evaluating the state of wear of the roll on the basis of the plurality of indexes acquired for at least one among the plurality of numbers of corners Ns obtained in correspondence with each of the plurality of portions.

Description

Roll wear condition evaluation method, operation method, roll wear condition evaluation device, operation device, and rolling equipment

[0001] The present disclosure relates to a roll wear state evaluation method, an operation method, a roll wear state evaluation device, an operation device, and rolling equipment.

[0002] When a metal sheet is processed in a machine including rolls, such as a rolling mill or a leveler, the rolls may wear due to contact with the metal sheet as they rotate, resulting in roll polygonization (N-gonization), in which the cross-sectional shape of the roll approaches a specific N-gon. When roll polygonization occurs and grows, irregularities corresponding to the polygonal shape of the roll are formed on the surface of the metal sheet in contact with the roll, which can cause problems with product quality or increase the frequency of roll replacement, resulting in reduced productivity. Therefore, it is desirable to appropriately understand the growth trend of roll polygonization and prevent roll polygonization.

[0003] Patent Document 1 describes a method of calculating a characteristic value indicating an index of change in the vibration amplitude of a rolling roll over time from vibration data of the rolling roll during rolling at a constant rotation speed of the rolling roll, and evaluating the growth tendency of N-gonalization of the rolling roll based on the characteristic value.

[0004] Patent No. 7179997

[0005] Incidentally, in order to quickly detect and deal with the growth of polygonal shape in a roll, it is desirable to grasp the wear state of the roll at an earlier stage.

[0006] In view of the above circumstances, at least one embodiment of the present invention aims to provide a roll wear state evaluation method, an operation method, a roll wear state evaluation device, an operation device, and rolling equipment that enable early detection of the wear state of a roll.

[0007] A method for evaluating the wear state of a roll according to at least one embodiment of the present invention comprises: a vibration data acquisition step of acquiring vibration data indicating vibration of the roll over a plurality of rotations of the roll for each of a plurality of portions of one or more metal plates while changing the rotational speed of the roll that rotates while in contact with the metal plates or another roll; an index acquisition step of acquiring, from the vibration data for each of the plurality of portions, an index using a vibration amplitude at a frequency corresponding to the number of corners N of the roll for each rotation of the roll; and an evaluation step of evaluating the wear state of the roll based on the plurality of indexes acquired for at least one number of corners N of the plurality of number of corners N obtained corresponding to each of the plurality of portions.

[0008] Furthermore, at least one embodiment of the present invention provides an operating method for a machine including a roll for processing a metal plate using the roll, the operating method comprising the steps of: obtaining an evaluation result of the wear state of the roll using the above-described wear state evaluation method; and changing the rotation speed of the roll based on the evaluation result.

[0009] Furthermore, the roll wear state evaluation device according to at least one embodiment of the present invention comprises: a vibration data acquisition unit configured to acquire, for each of a plurality of portions of one or more metal plates, vibration data indicating vibration of the roll over a plurality of rotations of the roll while changing the rotational speed of the roll that rotates while in contact with the metal plates or another roll; an index acquisition unit configured to acquire, for each of the plurality of portions, from the vibration data, an index using the vibration amplitude at a frequency corresponding to the number of corners N of the roll for each rotation of the roll; and an evaluation unit configured to evaluate the wear state of the roll based on the plurality of indices acquired for at least one number of corners N of the plurality of number of corners N obtained corresponding to each of the plurality of portions.

[0010] Furthermore, an operating device according to at least one embodiment of the present invention is an operating device for a machine that includes a roll and processes a metal plate using the roll, and includes: the above-mentioned wear state evaluation device configured to obtain an evaluation result of the wear state of the roll; and a control unit configured to change the rotation speed of the roll based on the evaluation result.

[0011] Furthermore, a rolling facility according to at least one embodiment of the present invention includes: a rolling device including rolls for rolling a metal plate; and the above-described wear condition evaluation device configured to evaluate the wear condition of the rolls.

[0012] According to at least one embodiment of the present invention, there are provided a roll wear state evaluation method, an operation method, a roll wear state evaluation device, an operation device, and rolling equipment that enable early detection of the wear state of a roll.

[0013] FIG. 1 is a schematic diagram of rolling equipment according to an embodiment; FIG. 2 is a schematic configuration diagram of a wear state evaluation device / operation device according to an embodiment; FIG. 3 is a schematic flowchart of a method for evaluating a wear state of a roll according to an embodiment; FIG. 4 is a chart showing an example of a frequency analysis result of vibration data of a rolling mill roll and a change in roll rotation speed; FIG. 5 is a graph showing an example of an analysis result of a time history of the magnitude of vibration level for each polygonal number N; FIG. 6 is a graph showing an index based on vibration amplitude acquired for a plurality of polygonal numbers N; FIG. 7 is a graph showing an index based on vibration amplitude acquired for a plurality of polygonal numbers N; FIG. 8 is a graph showing an example of a change in roll rotation speed over time in a method for evaluating a wear state according to an embodiment; FIG. 9 is an example of a graph showing a change in index based on vibration amplitude acquired by a method for evaluating a wear state according to an embodiment; FIG. 10 is an example of a graph showing a change in index based on vibration amplitude over time in a method for evaluating a wear state according to an embodiment;

[0014] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0015] A wear state evaluation method or evaluation device according to some embodiments evaluates the wear state of a roll that rotates while contacting a metal sheet or another roll. Hereinafter, as some embodiments of the present invention, a device or method for evaluating the wear state of a roll for rolling a metal sheet (a work roll that contacts the metal sheet or a backup roll that contacts the work roll (another roll)) will be described, but the present invention is not limited thereto. For example, in some embodiments, the wear state of a roll (a work roll that contacts the metal sheet or a backup roll that contacts the work roll (another roll)) constituting a leveler (such as a hot leveler or a tension leveler) for correcting the shape of a metal sheet may be evaluated.

[0016] (Configuration of Rolling Equipment) FIG. 1 is a schematic diagram of rolling equipment to which an operating device / wear state evaluation device and an operating method / wear state evaluation method according to some embodiments are applied. As shown in FIG. 1 , the rolling equipment 1 according to one embodiment includes a rolling equipment 2 including a rolling stand 10 configured to roll a metal sheet S, and a wear state evaluation device 51 configured to evaluate the wear state of the rolls 3 (rolls) of the rolling equipment 2. The rolling equipment 1 also includes a vibration measurement unit 90 for measuring vibrations of the rolls 3 constituting the rolling stand 10. In one embodiment, the wear state evaluation device 51 may function as part of an operating device 50 for operating the rolling equipment 2 (a machine including the rolls 3).

[0017] The rolling stand 10 includes a plurality of rolls 3 for rolling the metal sheet S, a reduction device 8 for applying a load to the rolls 3 to reduce the metal sheet S, a housing (not shown), etc. The reduction device 8 may include a hydraulic cylinder.

[0018] In the rolling mill 2 shown in Figure 1, the rolling rolls 3 include a pair of work rolls 4A, 4B arranged to sandwich the metal sheet S, and a pair of backup rolls 6A, 6B arranged on the opposite side of the pair of work rolls 4A, 4B from the metal sheet S, for supporting the pair of work rolls 4A, 4B, respectively. The work rolls 4A, 4B are rotatably supported by roll chocks (bearings) 5A, 5B, respectively. The backup rolls 6A, 6B are rotatably supported by roll chocks 7A, 7B, respectively. The roll chocks 5A, 5B and the roll chocks 7A, 7B are supported by housings (not shown).

[0019] In the rolling equipment 1 shown in Fig. 1, the vibration measurement unit 90 includes acceleration sensors 91-94 attached to the roll chocks 5A, 5B, 7A, and 7B, respectively. The acceleration sensors 91-94 are configured to detect vibrations in any direction of the roll chocks 5A, 5B, 7A, and 7B (e.g., vertical, horizontal, and / or the direction of the rotation axis of the roll 3), i.e., vibrations in any direction of the work rolls 4A and 4B and backup rolls 6A and 6B. Signals indicating the above-mentioned vibrations detected by the acceleration sensors 91-94 are sent to the wear state evaluation device 51.

[0020] In another embodiment, the vibration measuring unit 90 may include a displacement detecting unit configured to measure the displacement of the rolling roll 3 in any direction. In this case, the vibration of the rolling roll 3 may be calculated based on the measurement results by the displacement detecting unit. For example, a laser-type or eddy current-type displacement meter may be used as the displacement detecting unit. Alternatively, an imaging device (camera, etc.) may be used as the displacement detecting unit. In this case, the vibration of the rolling roll 3 may be calculated by imaging a portion of the rolling roll 3 with the imaging device and processing the obtained imaging data.

[0021] 2 is a schematic configuration diagram of a wear state evaluation device 51 and an operating device 50 according to one embodiment. As will be described in detail later, the wear state evaluation device 51 is configured to evaluate the wear state of the rolls 3. The operating device 50 includes the wear state evaluation device 51 and is configured to control the operation of the rolling mill 2 including the rolls 3.

[0022] The wear state evaluation device 51 is configured to receive a signal indicating the vibration of the rolling rolls 3 from the vibration measurement unit 90, and also to receive a signal indicating the rotation speed of the rolling rolls 3 (work rolls 4A, 4B, etc.) measured by the rotation speed measurement unit 96. The wear state evaluation device 51 is also configured to process the signals received in this manner.

[0023] 2 , the wear state evaluation device 51 (driving device 50) includes a vibration data acquisition unit 52, an index acquisition unit 54, and an evaluation unit 60. The driving device 50 also includes a control unit 64 and / or an output unit 66.

[0024] The vibration data acquisition unit 52 is configured to acquire vibration data indicating the vibration of the rolling roll 3 over multiple rotations of the rolling roll 3 (the roll to be evaluated; either the work rolls 4A, 4B or the backup rolls 6A, 6B) for each of multiple portions of one or more metal plates S, while changing the rotational speed of the rolling roll 3 that rotates while in contact with the metal plate S or other rolls.

[0025] Each of the plurality of portions of the one or more metal plates S may be a coil made of a single metal plate, or the plurality of portions of the one or more metal plates S may be a plurality of portions of a continuous metal plate S (a single coil or a plurality of coils connected by welding or the like).

[0026] The index acquisition unit 54 is configured to acquire, for each of a plurality of portions of one or more metal plates S, from the vibration data acquired by the vibration data acquisition unit 52, an index using the vibration amplitude at a frequency corresponding to the number of corners N of the rolling roll 3 for each rotation number of the rolling roll 3.

[0027] The evaluation unit 60 is configured to evaluate the wear state of the rolling roll 3 based on the above-mentioned multiple indicators acquired for at least one of the multiple polygonal numbers N obtained by the indicator acquisition unit 54 corresponding to each of the above-mentioned multiple parts.

[0028] The control unit 64 is configured to control the rolling mill 2 so as to change the operating conditions (such as the rotational speed of the rolls 3) based on the evaluation result of the wear state of the rolls 3 by the evaluation unit 60. The control unit 64 may be configured to adjust the current value of the motor 70 that drives the rolls 3 in order to control the rotational speed of the rolls 3.

[0029] The output unit 66 is configured to output the calculation results and evaluation results obtained by the wear state evaluation device 51. The calculation results and evaluation results obtained by the wear state evaluation device 51 may be output to a display unit 68 (such as a display) via the output unit 66.

[0030] The wear state evaluation device 51 (operating device 50) includes a computer equipped with a processor (CPU, GPU, etc.), a storage device (memory device; RAM, etc.), an auxiliary storage unit, an interface, etc. The wear state evaluation device 51 (operating device 50) receives signals from various measuring instruments (such as the vibration measurement unit 90 or rotation speed measurement unit 96 described above) via the interface. The processor is configured to process the signals received in this manner. This realizes the functions of the above-mentioned functional units (vibration data acquisition unit 52, index acquisition unit 54, evaluation unit 60, control unit 64, and / or output unit 66).

[0031] The processing contents of the wear state evaluation device 51 (operation device 50) are implemented as a program executed by a processor. The program may be stored in an auxiliary storage unit. When the program is executed, the program is loaded into a storage device. The processor reads the program from the storage device and executes the instructions contained in the program.

[0032] As the rolling of the metal sheet S continues in the rolling apparatus 2 described above, N-gonalization, in which the cross-sectional shape of the rolls 3 approaches a specific N-gon, may occur. Here, FIG. 13 is a schematic diagram of a rolling apparatus in which N-gonalization of the rolls 3 occurs. The rolling apparatus 2 shown in FIG. 13 includes multiple rolling stands 10A to 10C. The cross-sectional shape perpendicular to the axial direction of the rolls 3 is usually circular, as in the rolls 3 of the roll stands 10A or 10C. However, the cross-sectional shape of the rolls 3 (work rolls 4A, 4B and backup rolls 6A, 6B) of the roll stand 10B shown in FIG. 13 is an N-gon (specifically, a dodecagon), and N-gonalization has occurred in these rolls 3.

[0033] When N-gonalization of the rolling roll 3 occurs and grows, irregularities corresponding to the N-gonalization of the rolling roll 3 are formed on the surface of the metal sheet S rolled by the rolling roll 3, which may cause problems in terms of product quality. Therefore, it is desirable to appropriately grasp the state of N-gonalization of the rolling roll 3 and suppress deterioration in the quality of the product metal sheet.

[0034] In addition, in FIG. 13, a state where a dodecagon (N=12) has been formed in each rolling roll 3 is shown schematically, but in an actual rolling mill, N-gons where N is about 50 or 100 may be formed in the rolling roll 3, depending on the operating conditions such as the rotation speed of the rolling roll 3.

[0035] Furthermore, depending on the operating conditions and specifications (natural frequency, etc.) of the rolling mill 2, N-gonalization of the rolls 3 may occur in a specific rolling stand 10, or N-gonalization may occur in a specific roll 3 (work rolls 4A, 4B or backup rolls 6A, 6B) among the multiple rolls 3 constituting one rolling stand. For example, in the case of hot rolling performed at a relatively high temperature, N-gonalization is relatively likely to occur in the work rolls 4A, 4B. In addition, in the case of cold rolling performed at a relatively low temperature, N-gonalization is relatively likely to occur in the backup rolls 6A, 6B.

[0036] (Wear condition evaluation method and operation method) Next, a method for evaluating the wear condition of rolls according to some embodiments will be described. In the wear condition evaluation method described below, the polygonal state of the rolling rolls 3 (at least one of the work rolls 4A, 4B or the backup rolls 6A, 6B) is evaluated. Note that, although a method for evaluating the state of the rolling mill 2 using the above-mentioned wear condition evaluation device 51 will be described below, in some embodiments, some or all of the processing by the wear condition evaluation device 51 described below may be performed using another device or manually.

[0037] FIG. 3 is a schematic flowchart of a method for evaluating the wear state of a roll according to one embodiment.

[0038] In one embodiment, first, for each of a plurality of portions of one or more metal sheets S, the vibration of the rolling roll 3 (the work rolls 4A, 4B or backup rolls 6A, 6B to be evaluated) is measured over a plurality of rotations of the rolling roll 3 while the rotational speed of the rolling roll 3 (the work rolls 4A, 4B or backup rolls 6A, 6B to be evaluated) is changed sequentially, over a plurality of rotations of the rolling roll 3. The vibration data acquisition unit 52 acquires vibration data indicating the vibration of the rolling roll 3 measured by the vibration measurement unit 90 (S2).

[0039] In step S2, vibration data may be acquired for each of a plurality of portions of one or more metal sheets S while continuously changing (increasing or decreasing) the rotational speed of the rolling rolls 3, or vibration data may be acquired while changing the rotational speed of the rolling rolls 3 in a stepwise manner. Note that in step S2, vibration data may be acquired (measured) while the metal sheet S is being rolled by the rolling rolls 3 (i.e., while the rolling rolls 3 are being rotated while the metal sheet S is being pressed down).

[0040] Next, the index acquisition unit 54 acquires an index using the vibration amplitude at a frequency corresponding to the number of corners N of the rolling roll 3 for each rotation number of the rolling roll 3 from the vibration data acquired in step S2 for each of the multiple parts of one or more metal plates S (S4).

[0041] Here, the index acquired in step S4 and the method for acquiring the index for one of the plurality of portions of the metal sheet S will be described. In step S4, first, a frequency analysis is performed on the vibration data acquired in step S2, and a vibration amplitude A at a frequency corresponding to the number of corners N of the rolling roll 3 for each number of rotations i of the rolling roll 3 is calculated. Ｎ，ｉ In addition, A Ｎ，ｉ means the vibration amplitude at a frequency corresponding to the polygonal number N for the i-th rotation of the rolling roll 3. The frequency corresponding to the polygonal number N of the rolling roll 3 is the frequency of vibration resulting from the shape of the rolling roll 3 (N-polygon), and corresponds to the product (f×N) of the number of rotations (rotational speed) f of the rolling roll 3 and N.

[0042] The above-mentioned vibration amplitude A Ｎ，ｉ can be obtained, for example, as follows: That is, the vibration data obtained in step S2 is subjected to a time-frequency analysis. For the time-frequency analysis, a means such as a fast Fourier transform (FFT) or a wavelet transform can be used.

[0043] FIG. 4 is a chart showing an example of the results of time-frequency analysis of vibration data of the rolling roll 3 obtained during the rolling of one of multiple portions of a metal sheet S, and the change in the roll rotation speed when the vibration data was acquired. The horizontal axis of the chart in FIG. 4 represents time, and the vertical axis represents the vibration frequency and the roll rotation speed. The color intensity represents the magnitude of the vibration level, with darker colors indicating greater vibration. Note that FIG. 4 shows the results of frequency analysis of vibration data obtained when rolling a metal sheet S while increasing the rotation speed of the rolling roll 3 over time, divided into vibration data for each predetermined period (e.g., every second).

[0044] Based on the results of the frequency analysis described above, an order ratio analysis is performed from the relationship between the number of polygons N, the rotation speed (number of rotations f), and the vibration frequency, and the time history of the vibration level magnitude for each number of polygons N (also called order) is analyzed. Here, Fig. 5 is a graph showing an example of the analysis results of the time history of the vibration level magnitude for each number of polygons N (order). Since the number of rotations i of the roll corresponds one-to-one to time, from the analysis results, for each number of polygons N, the vibration amplitude A Ｎ，ｉ can be obtained.

[0045] Alternatively, the above-mentioned vibration amplitude A Ｎ，ｉ can be obtained, for example, as follows: That is, the vibration data obtained in step S2 is divided into parts for each number of rotations i, and frequency analysis is performed on each of the divided vibration data. As a result, for each number of rotations i, the vibration amplitude A at the frequency corresponding to each number of polygons N is obtained. Ｎ，ｉ can be obtained.

[0046] Next, in step S4, the vibration amplitude A obtained in this way is Ｎ，ｉ 6 and 7 show vibration amplitudes A obtained for multiple corner numbers N (N=32 to 63) of the rolling roll 3 during rolling of one of multiple portions of a certain metal sheet S. Ｎ，ｉ Indicator based on (ΣA Ｎ，ｉ , Σσ Ｎ，ｉ ＋ , Σσ Ｎ，ｉ － , and Σσ Ｎ，ｉ ; each of which will be described later).

[0047] In step S4, as the index mentioned above, the vibration amplitude A at the frequency corresponding to each polygon number N for each rotation number i from the start of rotation (i=1) to the end of rotation of the rolling roll 3 is calculated. Ｎ，ｉ Cumulative vibration amplitude ΣA, which is the sum of (i = 1, 2, 3, ...) Ｎ，ｉ may be obtained.

[0048] Cumulative vibration amplitude ΣA for a specific number of corners N Ｎ，ｉ and the cumulative vibration amplitude ΣA for all polygon numbers N Ｎ，ｉWhen the difference between the average value of and is larger than a specified value, it can be determined that the polygonization (N-gonization) at the specific number of polygons N is growing or attenuating. For example, in the case shown in FIG. 7, the cumulative vibration amplitude ΣA for N=35 to 40 (35 to 40 polygons; area A in FIG. 7) Ｎ，ｉ is the cumulative vibration amplitude ΣA for the other N Ｎ，ｉ Therefore, it can be determined that the polygonal shape of the roll 3 is growing for N=35 to 40. Note that the cumulative vibration amplitude ΣA for a specific polygonal number N is Ｎ，ｉ is the cumulative vibration amplitude ΣA for the other N Ｎ，ｉ When the value N is significantly smaller than the value N, it can be determined that the polygonal shape of the roll 3 is decreasing for the specific polygonal shape number N.

[0049] Alternatively, the cumulative vibration amplitude ΣA for a plurality of polygon numbers N Ｎ，ｉ If the variation in the cumulative vibration amplitude ΣA is large, it can be determined that polygonization (N-gonization) at any of the polygon numbers N is growing. For example, Ｎ，ｉ When the coefficient of variation (standard deviation divided by the average value) of is greater than a threshold value, it can be determined that the polygonalization of the roll 3 is growing or decreasing for a specific polygonal number N.

[0050] Alternatively, in step S4, the vibration amplitude growth ratio σ Ｎ，ｉ Here, the vibration amplitude growth ratio σ Ｎ，ｉ is the vibration amplitude (A) at the frequency corresponding to the number of polygons N in the first rotation number (for example, the i-th rotation) for each of the multiple number of polygons N. Ｎ，ｉ ) at a frequency corresponding to the number of polygons N in a second rotation (for example, the (i+1)th rotation) after the first rotation, Ｎ，（ｉ＋１） ) and the logarithm of that ratio (ln(A Ｎ，（ｉ＋１） / A Ｎ，ｉ )) may also be used.

[0051] Vibration amplitude growth ratio σ for each of a plurality of polygon numbers N Ｎ，ｉThe index using the positive cumulative growth rate Σσ for each number of polygons N Ｎ，ｉ ＋ , negative cumulative growth rate Σσ Ｎ，ｉ － , or the net cumulative growth rate Σσ Ｎ，ｉ (See FIGS. 6 and 7).

[0052] Positive cumulative growth rate Σσ for a given number of corners N Ｎ，ｉ ＋ is the number of oscillation amplitude growth ratios σ for the number of corners N Ｎ，ｉ It is the sum of positive values ​​among (i=1, 2, 3, . . . ).

[0053] Negative cumulative growth rate Σσ for a certain number of corners N Ｎ，ｉ － is the number of oscillation amplitude growth ratios σ for the number of corners N Ｎ，ｉ (i=1, 2, 3, . . . ) that have negative values.

[0054] Net cumulative growth rate Σσ for a certain number of polygons N Ｎ，ｉ is the positive cumulative growth rate Σσ for the number of corners N Ｎ，ｉ ＋ and negative cumulative growth rate Σσ Ｎ，ｉ － It is the harmony of.

[0055] A plurality of positive cumulative growth ratios Σσ obtained corresponding to a plurality of polygon numbers N, respectively. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － The variation of indicates the polygonal wear pattern of the roll 3. Therefore, for example, a plurality of positive cumulative growth ratios Σσ obtained corresponding to a plurality of polygonal numbers N are Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － Based on the comparison of the value indicating the dispersion of the coefficient of friction coefficient σ with the threshold value, the tendency of the polygonal shape to grow or decay in the mill roll 3 can be evaluated.

[0056] A plurality of positive cumulative growth ratios Σσ obtained corresponding to a plurality of polygon numbers N, respectively. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios ΣσＮ，ｉ － When the variation in is small (for example, the case shown in FIG. 6 ), it can be evaluated that the rolling roll 3 is in a state of dispersed growth in which polygonalization grows in a dispersed manner (i.e., on average) for a plurality of polygonal numbers N, and that there is no sign of sudden growth in polygonalization for a specific polygonal number N.

[0057] Multiple positive cumulative growth rates Σσ Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － The coefficient of variation (standard deviation divided by the mean value) can be used as a value indicating the variation of the values.

[0058] Alternatively, the positive cumulative growth rate Σσ for a particular number of corners N Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － The absolute values ​​of Σσ are the multiple positive cumulative growth ratios for multiple polygon numbers N. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － and a positive cumulative growth ratio Σσ for a specific polygon number N, which is smaller than the average value of the absolute values ​​of Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － The tendency of polygonal growth or attenuation in the mill roll 3 can be evaluated based on whether the difference between the absolute value of the

[0059] Positive cumulative growth rate Σσ for a specific number of corners N Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － Absolute value of (e.g., positive cumulative growth ratio Σσ for N=37 in FIG. 7 Ｎ，ｉ ＋ (see ), but there are multiple positive cumulative growth rates Σσ Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ －is smaller than the average AVG (see FIG. 7) of the absolute values ​​of the cumulative growth ratios, and the difference D (see FIG. 7) is large, it can be evaluated that the polygonization for that specific number of polygons N is in a state of saturated growth, with no growth or attenuation. In other words, if there is a number of polygons N for which the absolute value of the positive or negative cumulative growth ratio is locally small, it can be evaluated that the polygonization for that number of polygons N is in a state of saturated growth, with no growth or attenuation.

[0060] For example, in the case shown in FIG. 7, when N=35 to 40 (area B in FIG. 7), the positive cumulative growth rate Σσ Ｎ，ｉ ＋ The absolute value of Σσ Ｎ，ｉ ＋ is significantly smaller than the average value AVG of the absolute values ​​of N (i.e., it is locally small). Therefore, it can be evaluated that the polygonization for N=35 to 40 is in a state of saturated growth, with no growth or decay.

[0061] Alternatively, a plurality of positive cumulative growth ratios Σσ obtained corresponding to a plurality of numbers of polygons N, respectively, are Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － When the variation in the thickness is large (for example, when the above-mentioned coefficient of variation is large), it can be evaluated that the rolling roll 3 is in a state of saturated growth.

[0062] For the cases shown in Figure 7, the cumulative growth rate (Σσ Ｎ，ｉ ＋ or Σσ Ｎ，ｉ － ) it can be evaluated that the polygonization for N = 35 to 40 is in a saturated growth state with no growth or decay, and the oscillation amplitude growth ratio (σ Ｎ，ｉ 7, it can be evaluated that polygonal growth has occurred for N=35 to 40. In other words, in the case shown in Fig. 7, polygonal growth has already occurred for N=35 to 40, and it is predicted that if the operation of the rolling mill 2 continues under the same conditions, the current state in which polygonal growth has occurred for N=35 to 40 will be maintained.

[0063] Thus, the oscillation amplitude growth ratio (σＮ，ｉ ) and the cumulative growth rate (Σσ Ｎ，ｉ ＋ or Σσ Ｎ，ｉ － ) together, it is possible to evaluate the wear state of the roll in more detail.

[0064] As already mentioned, in some embodiments, vibration data of the rolling roll 3 is acquired for each of multiple portions of one or more metal plates S (step S2), and the above-mentioned indicators are acquired from the acquired vibration data (step S4).

[0065] 8 is a graph showing an example of a change in roll rotation speed over time in a wear state evaluation method according to an embodiment. Ｎ，ｉ 9 and 10 are examples of graphs showing changes over time in indices based on the above. Graphs #001 to #009 shown in Fig. 9 and Fig. 10 are equivalent to the graphs shown in Fig. 6 and Fig. 7, respectively.

[0066] As described above, in step S2, a plurality of portions of one or more metal sheets S (for example, nine portions #001 to #009 in the examples shown in FIGS. 8 to 10 ) are targeted for processing by the reduction rolls 3, and the vibration data described above is acquired for each of the plurality of portions. That is, vibration data is acquired for the plurality of portions (#001 to #009) of one or more metal sheets S while rolling them by sequentially changing the rotational speed of the reduction rolls 3.

[0067] 8, the rotation speed of the rolling rolls 3 may be increased from the minimum speed to the maximum speed for each portion (#001 to #009) of the metal sheet S. Furthermore, the rotation speed (including the minimum speed and the maximum speed) of the rolling rolls 3 may be different for each portion (#001 to #009) of the metal sheet S.

[0068] As described above, in step S4, the above-mentioned index corresponding to each of the plurality of numbers of polygons N is obtained for each of the plurality of portions of one or more metal plates S. This index is the cumulative vibration amplitude ΣA Ｎ，ｉ , positive cumulative growth rate Σσ Ｎ，ｉ ＋ , negative cumulative growth rate ΣσＮ，ｉ － , and / or the net cumulative growth rate Σσ Ｎ，ｉ For example, as shown in FIG. 8, from vibration data acquired while changing the rotation speed of the rolling roll 3 for the portions (#001 to #009) of the metal sheet S, the indexes (cumulative vibration amplitude ΣA Ｎ，ｉ , positive cumulative growth rate Σσ Ｎ，ｉ ＋ , negative cumulative growth rate Σσ Ｎ，ｉ － , and the net cumulative growth rate Σσ Ｎ，ｉ ) is obtained.

[0069] As described above, in steps S2 to S4, once the above-mentioned indicators for each of the multiple polygonal numbers N of the rolling roll 3 are obtained for each of the multiple portions (#001 to #009) of one or more metal plates S, the evaluation unit 60 evaluates the wear state of the rolling roll 3 based on the above-mentioned multiple indicators obtained for at least one of the multiple polygonal numbers N obtained corresponding to each of the multiple portions (#001 to #009) of the metal plate S (S6).

[0070] In some embodiments, in step S6, a plurality of cumulative vibration amplitudes ΣA for at least one polygon number N obtained corresponding to each of a plurality of portions (#001 to #009) of the metal plate S are Ｎ，ｉ Based on this, a specific polygon number N at which polygonization is growing or decreasing in the rolling roll 3 may be identified.

[0071] Cumulative vibration amplitude ΣA for a specific number of corners N Ｎ，ｉ The increase or decrease in the magnitude of the amplitude ΣA is an indicator of the degree of growth or attenuation of polygonalization of the roll 3 at the number of corners N. Therefore, the cumulative vibration amplitude ΣA for a specific number of corners N obtained for each of the multiple portions of the metal sheet S is Ｎ，ｉ From the increasing or decreasing tendency of , the degree of growth or attenuation of polygonalization at the polygon number N of the rolling roll 3 can be evaluated.

[0072] In the above embodiment, the cumulative vibration amplitude ΣA Ｎ，ｉ Therefore, the cumulative vibration amplitude ΣA for a plurality of polygons N is obtained. Ｎ，ｉThen, for each of the plurality of portions (#001 to #009) of one or more metal plates S, the cumulative vibration amplitude ΣA corresponding to each of the plurality of polygon numbers N can be calculated. Ｎ，ｉ Therefore, the cumulative vibration amplitude ΣA for a specific number of corners N for each of the multiple parts is obtained. Ｎ，ｉ Based on this, it is possible to determine whether polygonalization is growing or decaying for a specific polygon number N in the rolling roll 3.

[0073] In some embodiments, in step S6, a vibration amplitude growth ratio σ for at least one polygon number N obtained corresponding to each of the multiple portions (#001 to #009) of the metal plate S is calculated. Ｎ，ｉ Multiple indicators using positive cumulative growth rate Σσ Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － ) the tendency of polygonal growth or attenuation in the rolling roll 3 may be evaluated.

[0074] In one embodiment, in step S6, a plurality of positive cumulative growth ratios Σσ for at least one number of corners N obtained corresponding to each of a plurality of portions (#001 to #009) of the metal plate S are calculated. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － Based on a comparison between the value indicating the dispersion of the coefficient of friction coefficient σ and a threshold value, the tendency of the polygonal shape to grow or decay in the mill roll 3 may be evaluated.

[0075] In the above-described embodiment, a value indicating the variation in the positive cumulative growth ratio or the negative cumulative growth ratio is obtained for each of the multiple polygonal numbers N. Therefore, the tendency of the roll's polygonal growth or attenuation can be evaluated based on a comparison between the value and a threshold. For example, if the variation in the positive cumulative growth ratio or the negative cumulative growth ratio is small, it can be evaluated as a state of dispersed growth in which polygonal growth is dispersed for the multiple polygonal numbers N. Furthermore, a value indicating the variation in the positive cumulative growth ratio or the negative cumulative growth ratio corresponding to each of the multiple polygonal numbers N is obtained for each of the multiple portions (#001 to #009) of one or more metal sheets S. Therefore, a change in the tendency of the roll's polygonal growth or attenuation can be evaluated based on a change in the distribution (variation) of the positive cumulative growth ratio or the negative cumulative growth ratio for the multiple polygonal numbers N for each of the multiple portions.

[0076] In one embodiment, in step S6, the index (positive cumulative growth ratio Σσ) for a particular number of corners N is calculated. Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － The tendency of polygonal growth or attenuation in the rolling roll 3 is evaluated based on whether the absolute value of (N) is smaller than the average value of the absolute values ​​of the index for a plurality of polygonal numbers N and whether the difference between the average value of the absolute values ​​of the index for a plurality of polygonal numbers N and the absolute value of the index for a specific polygonal number N is equal to or greater than a threshold value.

[0077] In the above-described embodiment, for each of the multiple polygonal numbers N, the absolute value of the positive cumulative growth ratio or negative cumulative growth ratio is compared with the average value, and the tendency of polygonal growth or attenuation of the rolling roll 3 can be evaluated based on whether the difference between the absolute value and the average value is equal to or greater than a threshold. For example, if there is a polygonal number N in which the absolute value of the positive cumulative growth ratio or negative cumulative growth ratio is locally small, it can be evaluated that the polygonal growth for that polygonal number N is in a saturated growth state, in which there is no growth or attenuation. Then, for each of the multiple portions (#001 to #009) of one or more metal sheets S, it can be evaluated whether a saturated growth state has occurred as described above based on the positive cumulative growth ratio or negative cumulative growth ratio corresponding to each of the multiple polygonal numbers N, and therefore it is possible to evaluate changes in the tendency of polygonal growth or attenuation of the rolling roll 3.

[0078] More specifically, in step S6, the following evaluation can be made from the indices obtained for the multiple portions (#001 to #009) of the metal plate S shown in FIGS. 9 and 10, for example.

[0079] First, for each part (#001 to #009) of the metal plate S, a positive cumulative growth ratio Σσ Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － 9 and 10, it is judged whether the state is a dispersed growth state of polygonization or a saturated growth state in the rolling roll 3. In the example shown in FIG. 9 and FIG. 10, in the portions #001 to #008, the cumulative growth ratio Σσ is positive at N=35 to 40. Ｎ，ｉ ＋ and negative cumulative growth rate Σσ Ｎ，ｉ － is locally small (see the area surrounded by the dashed line in FIGS. 9 and 10), it can be determined that the state is saturated growth.

[0080] Next, for the polygon number N (in this example, N=35 to 40) that is in a state of saturated growth, it is determined whether polygonization is growing. In the example shown in Figures 9 and 10, for the parts #001 to #008, the cumulative vibration amplitude ΣA Ｎ，ｉ generally increases with the passage of time (i.e., from part #001 to part #008). Therefore, it can be determined that the polygonal shape of the roll 3 becomes more pronounced when the number of polygons N is 35 to 40.

[0081] In addition, the cumulative vibration amplitude ΣA obtained for each part (#001 to #009) of the metal plate S Ｎ，ｉ By comparing the value with a threshold value or variance, it is possible to determine the timing for changing the speed of the rolling rolls 3. In the example shown in FIGS. 9 and 10, for the portions #001 to #007, the cumulative vibration amplitude ΣA Ｎ，ｉ is less than the threshold (shown by the dashed straight line), but in part #008, the cumulative vibration amplitude ΣA Ｎ，ｉexceeds the threshold value. Therefore, by changing the speed of the rolling rolls 3 at this point, it is possible to suppress the growth of polygonalization with respect to the number of polygons N that has become apparent.

[0082] For example, in the example shown in Fig. 8, when rolling portion #009 of the metal sheet S (i.e., when vibration data was acquired), the rotational speed of the rolling roll 3 was significantly reduced compared to when rolling portions 001 to #008, which resulted in a change in the tendency of the wear state of the rolling roll 3, as shown in Figs. 9 and 10. Figs. 9 and 10 show that when rolling portion #009 of the metal sheet S, the cumulative vibration amplitude ΣA Ｎ，ｉ significantly decreased, and polygonization attenuated for N = 35-40, and the positive cumulative growth ratio Σσ Ｎ，ｉ ＋ and negative cumulative growth rate Σσ Ｎ，ｉ － Since the variation in the diameter of the roll 3 is reduced, it can be understood that the polygonal shape of the roll 3 has become dispersed and grown.

[0083] In this way, vibration data is acquired for each of the plurality of portions (#001 to #009) of one or more metal plates S, and the vibration amplitude A at the frequency corresponding to each of the plurality of polygonal numbers N of the rolling roll 3 is calculated from the vibration data. Ｎ，ｉ Since multiple indices are obtained using the above, it is possible to grasp the changes over time in multiple indices corresponding to multiple polygon numbers N. Therefore, it is possible to grasp the changes in the wear state of the rolling rolls at an early stage.

[0084] In some embodiments, in step S6, a plurality of positive cumulative growth ratios Σσ for at least one number of corners N obtained corresponding to each of a plurality of portions (#001 to #009) of the metal plate S are calculated. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － The amount of wear of the rolling roll 3 may be evaluated based on at least one of the above.

[0085] The positive and negative cumulative growth ratios for a specific polygonal number N are correlated with the wear amount due to polygonization of the roll 3 corresponding to each polygonal number N. Therefore, for each of a plurality of polygonal numbers N, the positive cumulative growth ratio Σσ Ｎ，ｉ ＋ or negative cumulative growth rate Σσ Ｎ，ｉ － In the above embodiment, for each of the plurality of portions (#001 to #009) of one or more metal sheets S, a plurality of positive cumulative growth ratios Σσ for each of the plurality of polygon numbers N are calculated. Ｎ，ｉ ＋ or multiple negative cumulative growth ratios Σσ Ｎ，ｉ － Since the cumulative growth ratios are obtained, it is possible to grasp the change in the amount of wear of the rolling roll 3 based on the plurality of positive cumulative growth ratios or the plurality of negative cumulative growth ratios.

[0086] As an index showing the amount of wear of the rolling roll 3, the absolute value of the positive cumulative growth ratio for a plurality of polygon numbers N (|Σσ Ｎ，ｉ ＋ |), the sum or average value of the negative cumulative growth ratios for multiple polygon numbers N (|Σσ Ｎ，ｉ － |) can be used as a sum or average.

[0087] In addition, when it is highly likely that the rolling roll 3 will maintain a saturated growth state at a constant roll rotation speed for a specific polygonal number N (see Figure 7), the cumulative growth ratio for the region of polygonal number N where growth is saturated (saturated region; N = 35 to 40 in Figure 7) may be excluded from the calculation of the index indicating the above-mentioned wear amount.

[0088] In some embodiments, in step S6, for each of a plurality of numbers of polygons N, a vibration amplitude A is calculated from a plurality of rotation numbers (i=1, 2, 3, . . . ). Ｎ，ｉis obtained, and the natural frequency (hereinafter simply referred to as natural frequency) at which polygonalization is likely to occur of the rolling mill 2 (machine including rolls) including the rolls 3 is obtained based on the correlation between the polygonal number N of the rolls 3 and the first rotation speed. The rolling mill 2 (machine including rolls) including the rolls 3 has many natural frequencies, but distinguishing the natural frequencies at which polygonalization is likely to occur among them provides effective information for preventing polygonalization.

[0089] As can be seen from the graph in FIG. 5, the roll vibration amplitude A for each number of corners N Ｎ，ｉ changes depending on the number of roll rotations i (i.e., depending on time) and has a maximum value. For a plurality of numbers of corners N, the vibration amplitude A of the rolling roll 3 for each number of corners N is Ｎ，ｉ and the vibration amplitude A Ｎ，ｉ When the product (N×f1) of the first rotation speed f1, which is the rotation speed (rotational speed) of the rolling roll 3 corresponding to the rotation number i at which the value of α is maximized, and the polygonal number N is a substantially constant value, the product (N×f1) substantially coincides with the natural frequency fa of the rolling mill 2 including the rolling roll 3. In other words, when a graph showing the relationship between the polygonal number N and the first rotation speed f1 appears in the shape of a hyperbola as shown in FIG. 11, the natural frequency (fa≈N×f1) of the rolling mill 2 including the rolling roll 3 can be grasped. Note that FIG. 11 shows the relationship between the polygonal number N and the vibration amplitude A Ｎ，ｉ 10 is a graph showing an example of the correlation between the rotation speed of the roll and the maximum value of the

[0090] In this way, the number of corners N of the rolling roll 3 and the vibration amplitude A of the rolling roll 3 among the multiple rotation numbers (i=1, 2, 3, . . . ) are Ｎ，ｉ The natural frequency of the rolling mill 2 including the reduction rolls 3 can be obtained based on the correlation between the first rotation speed f1 of the rolls corresponding to the rotation number i at which the natural frequency f1 is maximized.

[0091] In the above-described embodiment, the above-described correlations are obtained for each of the multiple polygonal numbers N for each of the multiple portions (#001 to #009) of one or more metal plates S, and based on this, it is possible to grasp changes in the polygonalization tendency of the rolling roll 3 (changes in growth pattern, natural frequency, etc.).

[0092] 12 is a schematic flowchart of a method for evaluating the wear state of a roll according to an embodiment. In some embodiments, the above-mentioned index (cumulative vibration amplitude ΣA Ｎ，ｉ , positive cumulative growth rate Σσ Ｎ，ｉ ＋ , negative cumulative growth rate Σσ Ｎ，ｉ － , and / or the net cumulative growth rate Σσ Ｎ，ｉ The predicted values ​​of the indices obtained in step S10 are then compared with the indices obtained in steps S2 to S4 (indices obtained from the actually measured vibration data) (S12). Based on this comparison, the prediction model used in the calculation in step S10 is corrected (S14).

[0093] In step S10, the position and shape of the roll to be evaluated at each time are calculated from a prediction model using the spring constant between the roll to be evaluated (rolling roll 3) and the metal sheet S or other rolls that come into contact with the roll, and based on this, the above-mentioned index (cumulative vibration amplitude ΣA Ｎ，ｉ , positive cumulative growth rate Σσ Ｎ，ｉ ＋ , negative cumulative growth rate Σσ Ｎ，ｉ － , and / or the net cumulative growth rate Σσ Ｎ，ｉ Calculate the predicted value of the following:

[0094] The predictive model used in step S10 may include an equation of motion for the roll being evaluated, expressed using spring constants, damping constants, and friction constants between the roll and the metal plate S and / or other rolls that it comes into contact with.

[0095] In steps S12 to S14, the prediction model (e.g., the above-mentioned spring constant, wear constant, etc.) is modified so that the indexes calculated from the prediction model approach the indexes obtained in steps S2 to S4 (indexes obtained from the actually measured vibration data).

[0096] According to the above-described embodiment, the prediction model can be corrected based on a comparison between the predicted values ​​of the above-described multiple indices corresponding to at least one of the multiple polygonal numbers N obtained by calculation using a prediction model using a spring constant between the reduction roll 3 and the metal sheet S or another roll, and the above-described multiple indices (indices based on vibration measurement data) corresponding to the polygonal number N obtained in the index obtaining step. This makes it possible to improve the prediction accuracy of the above-described multiple indices, and also improve the accuracy of evaluation of the wear state of the roll based on the predicted multiple indices.

[0097] In some embodiments of the method for operating a machine for processing a metal sheet using rolls (e.g., a rolling mill 2 for rolling a metal sheet S using rolls 3), the control unit 64 changes the rotational speed of the rolls (e.g., roll rolls 3) based on the evaluation results of the wear state of the rolls in the procedure of steps S2 to S4 described above. The control unit 64 may be configured to adjust the current value of the motor 70 that drives the rolls 3 so that the post-change roll rotational speed is determined from the evaluation results of the wear state of the rolls.

[0098] For example, when it is determined by the procedure of steps S2 to S4 described above that polygonization at a specific number of sides N has grown significantly, the growth of polygonization at that specific number of sides N can be suppressed by changing the rotation speed of the roll to a higher or lower speed than before.

[0099] According to the method of the above-described embodiment, the rotation speed of the roll is changed based on the results of evaluating the wear state of the roll by the method including the above-described steps S2 to S4, so that the progression of the growth of polygonization occurring in the roll can be appropriately suppressed.

[0100] The contents described in each of the above embodiments can be understood, for example, as follows.

[0101] [1] A method for evaluating the wear state of a roll according to at least one embodiment of the present invention comprises: a vibration data acquisition step (S2) for acquiring vibration data indicating vibration of a roll (e.g., a rolling roll 3) over a plurality of rotations (i) of the roll while changing the rotational speed of the roll (e.g., a rolling roll 3) that rotates while contacting the metal plate or another roll, for each of a plurality of portions (#001 to #009) of one or more metal plates (S); an index acquisition step (S4) for acquiring, from the vibration data for each of a plurality of polygonal numbers N of the roll, an index using a vibration amplitude at a frequency corresponding to the polygonal number N for each rotation number of the roll; and an evaluation step (S6) for evaluating the wear state of the roll based on a plurality of the indexes acquired for at least one polygonal number N of the plurality of polygonal numbers N obtained corresponding to each of the plurality of portions.

[0102] In the method [1] above, roll vibration data is acquired while changing the rotational speed of the roll, and therefore, multiple indices can be acquired from vibration data acquired over a relatively short period of time, using vibration amplitudes at frequencies corresponding to the multiple polygonal numbers N of the roll. Furthermore, the multiple indices corresponding to the multiple polygonal numbers N are acquired for each of multiple portions of one or more metal plates, and therefore, changes in the indices can be easily grasped based on the indices for each of the multiple portions, and thus, the state of roll wear (polygonalization, etc.) can be easily grasped. Therefore, the method [1] above allows the state of roll wear to be grasped at an early stage.

[0103] [2] In some embodiments, in the method of [1] above, in the index acquisition step, for each of the plurality of portions, a cumulative vibration amplitude (ΣA Ｎ，ｉ) is acquired as the index, and in the evaluation step, a specific number of corners N at which polygonization is growing or attenuating in the roll is identified based on the plurality of cumulative vibration amplitudes for the at least one number of corners N acquired corresponding to each of the plurality of portions.

[0104] According to the method [2] above, the cumulative vibration amplitude (the sum of the vibration amplitudes at the frequencies corresponding to each of the polygonal numbers N for each rotation speed of the roll) is obtained for each of the multiple polygonal numbers N, making it possible to grasp the distribution of the cumulative vibration amplitude for the multiple polygonal numbers N. Furthermore, the cumulative vibration amplitude corresponding to each of the multiple polygonal numbers N is obtained for each of the multiple portions of one or more metal plates, making it possible to identify whether polygonalization is growing or decaying for a specific polygonal number N in the roll, based on the cumulative vibration amplitude for a specific polygonal number N for each of the multiple portions.

[0105] [3] In some embodiments, in the method of [1] above, in the index acquisition step, for each of the plurality of portions, a vibration amplitude growth ratio (σ) is calculated from the vibration data for each of the plurality of polygonal numbers N, the vibration amplitude being a ratio of a vibration amplitude at a frequency corresponding to the polygonal number N in a first rotation number to a vibration amplitude at a frequency corresponding to the polygonal number N in a second rotation number that is later than the first rotation number. Ｎ，ｉ ) and in the evaluation step, a tendency of growth or attenuation of polygonalization in the roll is evaluated based on the plurality of indices for the at least one polygon number N obtained corresponding to each of the plurality of portions.

[0106] According to the method [3] above, an index using a vibration amplitude growth ratio (a value calculated from the ratio of the vibration amplitude at a frequency corresponding to the polygonal number N at the first number of rotations to the vibration amplitude at a frequency corresponding to the polygonal number N at the second number of rotations) is obtained for each of a plurality of polygonal numbers N, so that it is possible to grasp the distribution of the index using the vibration amplitude growth ratio for a plurality of polygonal numbers N. Then, an index using the vibration amplitude growth ratio corresponding to each of a plurality of polygonal numbers N is obtained for each of a plurality of portions of one or more metal plates, so that it is possible to evaluate a change in the tendency (growth pattern, etc.) of the growth or decay of polygonalization of the roll from the distribution of the index using the vibration amplitude growth ratio for a plurality of polygonal numbers N for each of the plurality of portions.

[0107] [4] In some embodiments, in the method of [3] above, the index using the oscillation amplitude growth ratio for each of the plurality of polygon numbers N is a positive cumulative growth ratio (Σσ Ｎ，ｉ ＋ ), or a negative cumulative growth ratio (Σσ Ｎ，ｉ － ) In the evaluation step, a tendency of growth or attenuation of polygonalization in the roll is evaluated based on at least one of a plurality of positive cumulative growth ratios or a plurality of negative cumulative growth ratios for the at least one polygon number N obtained corresponding to each of the plurality of portions.

[0108] The positive and negative cumulative growth ratios for a specific polygonal number N indicate the degree of growth and attenuation of polygonalization for that polygonal number N, respectively. According to the method of [4] above, a positive or negative cumulative growth ratio is obtained for each of multiple polygonal numbers N, making it possible to grasp the distribution of positive or negative cumulative growth ratios for each of multiple polygonal numbers N. Furthermore, since a positive or negative cumulative growth ratio corresponding to each of multiple polygonal numbers N is obtained for each of multiple portions of one or more metal plates, it is possible to evaluate changes in the tendency (growth pattern, etc.) of growth or attenuation of polygonalization of the roll from the distribution of the positive or negative cumulative growth ratios for the multiple polygonal numbers N for each of the multiple portions.

[0109] [5] In some embodiments, in the method of [4] above, the evaluation step evaluates the tendency of polygonal growth or attenuation in the roll based on a comparison between a value indicating the variation of at least one of the positive cumulative growth ratios or the negative cumulative growth ratios for the at least one polygon number N obtained corresponding to each of the multiple portions and a threshold value.

[0110] According to the method [5] above, a value indicating the variation in the positive cumulative growth ratio or the negative cumulative growth ratio is obtained for each of a plurality of polygonal numbers N. Therefore, the tendency of the growth or attenuation of polygonalization of the roll can be evaluated based on a comparison between the obtained value and a threshold value. For example, if the variation in the positive cumulative growth ratio or the negative cumulative growth ratio is small, it can be evaluated that the state is a dispersed growth state in which polygonalization grows dispersedly for the plurality of polygonal numbers N. Furthermore, a value indicating the variation in the positive cumulative growth ratio or the negative cumulative growth ratio corresponding to each of the plurality of polygonal numbers N is obtained for each of a plurality of portions of one or more metal plates. Therefore, a change in the tendency of the growth or attenuation of polygonalization of the roll can be evaluated from a change in the distribution (variation) of the positive cumulative growth ratio or the negative cumulative growth ratio for the plurality of polygonal numbers N for each of the plurality of portions.

[0111] [6] In some embodiments, in the method of [4] above, the evaluation step evaluates the tendency of polygonal growth or decay in the roll based on whether the absolute value of the index for a specific number of polygons N is smaller than the average value of the absolute values ​​of the index for the multiple numbers of polygons N, and whether the difference between the average value of the absolute values ​​of the index for the multiple numbers of polygons N and the absolute value of the index for the specific number of polygons N is equal to or greater than a threshold.

[0112] According to the method of [6] above, for each of a plurality of polygonal numbers N, the absolute value of the positive cumulative growth ratio or the negative cumulative growth ratio is compared with the average value, and the tendency of the polygonal growth or attenuation of the roll can be evaluated based on whether the difference between the absolute value and the average value is equal to or greater than a threshold. For example, if there is a polygonal number N for which the absolute value of the positive cumulative growth ratio or the negative cumulative growth ratio is locally small, it can be evaluated that the polygonal growth for that polygonal number N is in a saturated growth state, where the polygonal growth is neither growing nor attenuating. Then, for each of a plurality of portions of one or more metal sheets, it can be evaluated whether the saturated growth state is occurring as described above based on the positive cumulative growth ratio or the negative cumulative growth ratio corresponding to each of a plurality of polygonal numbers N, and therefore it is possible to evaluate changes in the tendency of the polygonal growth or attenuation of the roll.

[0113] [7] In some embodiments, in the method of [4] above, the evaluation step evaluates the amount of wear of the roll based on at least one of the plurality of positive cumulative growth ratios or the plurality of negative cumulative growth ratios for the at least one number of corners N obtained corresponding to each of the plurality of portions.

[0114] The positive and negative cumulative growth ratios for a specific polygonal number N correlate with the amount of wear due to polygonization of the roll corresponding to each polygonal number N. According to the method of [7] above, the amount of wear of the roll can be evaluated based on the positive or negative cumulative growth ratio for each of multiple polygonal numbers N. Then, for each of multiple portions of one or more metal plates, multiple positive or negative cumulative growth ratios are obtained for each of multiple polygonal numbers N, so that changes in the amount of wear of the roll can be understood based on the multiple positive or negative cumulative growth ratios.

[0115] [8] In some embodiments, in the method of [3] above, in the evaluation step, a first rotation speed (f1) of the roll corresponding to the rotation number among the plurality of rotation numbers at which the vibration amplitude is maximized is obtained for each of the plurality of polygonal numbers N, and a natural frequency of a machine including the roll is obtained based on the correlation between the polygonal number N of the roll and the first rotation speed.

[0116] For each polygonal number N, when the product of the roll rotation speed and the polygonal number N coincides with the natural frequency, the vibration amplitude tends to be maximized. Furthermore, for multiple polygonal numbers N, when the product of the roll rotation speed and the polygonal number N when the roll vibration amplitude is maximized is a specific, approximately constant value, this approximately constant value is likely to be the natural frequency of the machine including the roll. According to the method of [8] above, for each of multiple polygonal numbers N, the first rotation speed of the roll corresponding to the rotation number at which the roll vibration amplitude is maximized is acquired. Therefore, the natural frequency of the machine including the roll can be acquired based on the correlation between the polygonal number N and the first rotation speed. For example, if the product of the first rotation speed and the polygonal number N coincides with a specific, approximately constant value in the above correlation, this approximately constant value is likely to coincide with the natural frequency of the machine including the roll. In this way, the natural frequency of the machine including the roll can be identified. Then, the above-mentioned correlations are obtained for each of the multiple polygonal numbers N for each of the multiple parts of one or more metal plates, and based on this, changes in the polygonalization tendency of the roll (changes in growth pattern, natural frequency, etc.) can be grasped.

[0117] [9] In some embodiments, in the methods of [1] to [8] above, the wear state evaluation method includes: a calculation step (S10) of acquiring a predicted value of the index for at least one number of corners N among the plurality of numbers of corners N by calculation using a prediction model that uses a spring constant between the roll and the metal plate, or between the roll and the other roll; and a correction step (S12 to S14) of correcting the prediction model based on a comparison between the index for the at least one number of corners N acquired in the index acquisition step and the predicted value acquired in the calculation step.

[0118] According to the method [9], the prediction model can be corrected based on a comparison between predicted values ​​of the above-mentioned multiple indices corresponding to each of the multiple polygonal numbers N obtained by calculation using a prediction model using a spring constant between the roll and the metal plate or another roll and the above-mentioned multiple indices (indices based on vibration measurement data) corresponding to each of the multiple polygonal numbers N obtained in the index obtaining step. This makes it possible to improve the prediction accuracy of the above-mentioned multiple indices and also improve the accuracy of evaluation of the wear state of the roll based on the predicted multiple indices.

[0119]

[10] An operating method according to at least one embodiment of the present invention is a method for operating a machine (e.g., rolling mill 2) that includes a roll (e.g., a rolling roll 3) and processes a metal plate using the roll, and includes the steps of (S2 to S6) obtaining an evaluation result of the wear state of the roll using the wear state evaluation method described in any one of [1] to [9] above, and changing the rotation speed of the roll based on the evaluation result.

[0120] According to the method

[10] above, the rotation speed of the roll is changed based on the results of evaluating the wear state of the roll by the method [1] above, so that the progression of the growth of polygonization occurring in the roll can be appropriately suppressed.

[0121]

[11] A roll wear state evaluation device (51) according to at least one embodiment of the present invention comprises: a vibration data acquisition unit (52) configured to acquire vibration data indicating vibration of a roll (e.g., a rolling roll 3) rotating in contact with the metal plate or another roll for each of a plurality of portions (#001 to #009) of the one or more metal plates (S) over a plurality of rotations (i) of the roll while changing the rotation speed of the roll; an index acquisition unit (54) configured to acquire, from the vibration data for each of a plurality of polygonal numbers N of the roll, an index using a vibration amplitude at a frequency corresponding to the polygonal number N for each rotation number of the roll; and an evaluation unit (60) configured to evaluate the wear state of the roll based on a plurality of the indexes acquired for at least one polygonal number N of the plurality of polygonal numbers N obtained corresponding to each of the plurality of portions.

[0122] In the configuration

[11] above, roll vibration data is acquired while changing the rotational speed of the roll, so that multiple indices can be acquired from vibration data acquired over a relatively short period of time, using vibration amplitudes at frequencies corresponding to the multiple polygonal numbers N of the roll. Furthermore, the multiple indices corresponding to the multiple polygonal numbers N are acquired for each of multiple portions of one or more metal plates, so that changes in the indices can be easily grasped based on the indices for each of the multiple portions, i.e., the state of roll wear (polygonalization, etc.) can be easily grasped. Therefore, the configuration

[11] above allows the state of roll wear to be grasped at an early stage.

[0123]

[12] An operating device (50) according to at least one embodiment of the present invention is an operating device for a machine including a roll and for processing a metal plate using the roll, and includes: a wear state evaluation device (51) according to the above

[11] configured to obtain an evaluation result of the wear state of the roll; and a control unit (64) configured to change the rotation speed of the roll based on the evaluation result.

[0124] According to the configuration

[12] above, the rotation speed of the roll is changed based on the results of evaluation of the wear state of the roll by the wear state evaluation device of

[11] above, so that the progression of the growth of polygonal shapes occurring in the roll can be appropriately suppressed.

[0125]

[13] A rolling facility (1) according to at least one embodiment of the present invention comprises: a rolling device (2) including rolls (rolling rolls 3) for rolling a metal plate (S); and the wear state evaluation device according to

[11] above, configured to evaluate the wear state of the rolls.

[0126] In the configuration

[13] above, roll vibration data is acquired while changing the rotational speed of the roll, so that multiple indices can be acquired from vibration data acquired over a relatively short period of time, using vibration amplitudes at frequencies corresponding to the multiple polygonal numbers N of the roll. Furthermore, the multiple indices corresponding to the multiple polygonal numbers N are acquired for each of multiple portions of one or more metal plates, so that changes in the indices can be easily grasped based on the indices for each of the multiple portions, i.e., the state of roll wear (polygonalization, etc.) can be easily grasped. Therefore, the configuration

[13] above allows the state of roll wear to be grasped at an early stage.

[0127] The above describes an embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and also includes forms in which the above-described embodiment is modified, or forms in which these forms are appropriately combined.

[0128] In this specification, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "identical," "equal," and "homogeneous," not only express a state in which there is a strict equivalence, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions expressing shapes such as a rectangular shape or a cylindrical shape not only express shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0129] REFERENCE SIGNS LIST 1 Rolling equipment 2 Rolling mill device 3 Rolling roll 4A Work roll 4B Work roll 5A Roll chock 5B Roll chock 6A Backup roll 6B Backup roll 7A Roll chock 7B Roll chock 8 Screw down device 10 Rolling stand 10A Rolling stand 10B Rolling stand 10C Rolling stand 50 Operating device 51 Wear state evaluation device 52 Vibration data acquisition unit 54 Index acquisition unit 60 Evaluation unit 64 Control unit 66 Output unit 68 Display unit 70 Motor 90 Vibration measurement unit 91 Acceleration sensor 92 Acceleration sensor 93 Acceleration sensor 94 Acceleration sensor 96 Rotation speed measurement unit S Metal plate

Claims

1. A method for evaluating the wear condition of a roll, comprising: a vibration data acquisition step for acquiring vibration data indicative of vibration of the roll over a plurality of rotations of the roll for each of a plurality of portions of one or more metal plates while changing the rotational speed of the roll which rotates while in contact with the metal plates or another roll; an index acquisition step for acquiring from the vibration data for each of a plurality of polygonal numbers N of the roll, an index using a vibration amplitude at a frequency corresponding to the polygonal number N for each rotation number of the roll, for each of the plurality of portions; and an evaluation step for evaluating the wear condition of the roll based on a plurality of the indexes acquired for at least one of the plurality of polygonal numbers N obtained corresponding to each of the plurality of portions.

2. The method for evaluating the wear condition of a roll as described in claim 1, wherein in the index acquisition step, for each of the multiple parts, a cumulative vibration amplitude is acquired from the vibration data as the index, for each of the multiple polygonal numbers N, which is the sum of the vibration amplitudes at a frequency corresponding to the polygonal number N for each rotation of the roll, and in the evaluation step, a specific polygonal number N at which polygonization is growing or decreasing in the roll is identified based on the multiple cumulative vibration amplitudes for at least one of the polygonal numbers N acquired corresponding to each of the multiple parts.

3. The method for evaluating the wear condition of a roll as described in claim 1, wherein in the index acquisition step, for each of the plurality of portions, an index is acquired from the vibration data using a vibration amplitude growth ratio, which is the ratio of the vibration amplitude at a frequency corresponding to the polygonal number N at a first rotation number to the vibration amplitude at a frequency corresponding to the polygonal number N at a second rotation number that is later than the first rotation number, and in the evaluation step, a tendency for the growth or decay of polygonalization in the roll is evaluated based on the plurality of indexes for at least one of the polygonal numbers N acquired corresponding to each of the plurality of portions.

4. The method for evaluating the wear condition of a roll as described in claim 3, wherein the index using the vibration amplitude growth ratio for each of the multiple polygonal numbers N includes a positive cumulative growth ratio which is the sum of the vibration amplitude growth ratios having positive values, or a negative cumulative growth ratio which is the sum of the vibration amplitude growth ratios having negative values, and the evaluation step evaluates a tendency of growth or attenuation of polygonization in the roll based on at least one of the multiple positive cumulative growth ratios or the multiple negative cumulative growth ratios for the at least one polygonal number N obtained corresponding to each of the multiple portions.

5. A method for evaluating the wear condition of a roll as described in claim 4, wherein the evaluation step evaluates the tendency of the growth or attenuation of polygonization in the roll based on a comparison between a value indicating the variation of at least one of the multiple positive cumulative growth ratios or the multiple negative cumulative growth ratios for at least one polygon number N obtained corresponding to each of the multiple portions and a threshold value.

6. A method for evaluating the wear condition of a roll as described in claim 4, wherein in the evaluation step, the tendency of the roll to grow or decay in polygonization is evaluated based on whether or not the absolute value of the index for a specific number of polygons N is smaller than the average value of the absolute values ​​of the index for the multiple numbers of polygons N, and whether or not the difference between the average value of the absolute values ​​of the index for the multiple numbers of polygons N and the absolute value of the index for the specific number of polygons N is equal to or greater than a threshold value.

7. A method for evaluating the wear condition of a roll as described in claim 4, wherein in the evaluation step, the amount of wear of the roll is evaluated based on at least one of a plurality of the positive cumulative growth ratios or a plurality of the negative cumulative growth ratios for the at least one polygon number N obtained corresponding to each of the plurality of portions.

8. A method for evaluating the wear condition of a roll as described in any one of claims 1 to 7, wherein in the evaluation step, a first rotational speed of the roll corresponding to a rotational speed among the multiple rotational speeds at which the vibration amplitude is maximized is obtained for each of the multiple polygonal numbers N, and a natural frequency of a machine including the roll is obtained based on a correlation between the polygonal number N of the roll and the first rotational speed.

9. A wear condition evaluation method as claimed in any one of claims 1 to 7, comprising: a calculation step of acquiring a predicted value of the index for at least one of the multiple polygon numbers N by calculation using a predictive model using a spring constant between the roll and the metal plate, or between the roll and the other roll; and a correction step of correcting the predictive model based on a comparison between the index for the at least one polygon number N acquired in the index acquisition step and the predicted value acquired in the calculation step.

10. A method for operating a machine including a roll for processing a metal plate using said roll, comprising the steps of: obtaining an evaluation result of the wear state of said roll using a wear state evaluation method according to any one of claims 1 to 7; and changing the rotational speed of said roll based on said evaluation result.

11. A roll wear condition evaluation device comprising: a vibration data acquisition unit configured to acquire, for each of a plurality of portions of one or more metal plates, vibration data indicative of vibration of the roll over a plurality of rotations of the roll while changing the rotational speed of the roll which rotates while in contact with the metal plates or another roll; an index acquisition unit configured to acquire, for each of the plurality of portions, from the vibration data, an index using a vibration amplitude at a frequency corresponding to the number of corners N of the roll for each rotation number of the roll; and an evaluation unit configured to evaluate the wear condition of the roll based on the multiple indexes acquired for at least one number of corners N of the multiple number of corners N obtained corresponding to each of the plurality of portions.

12. An operating device for a machine including a roll and for processing a metal plate using the roll, comprising: the wear condition evaluation device according to claim 11 configured to obtain an evaluation result of the wear condition of the roll; and a control unit configured to change the rotation speed of the roll based on the evaluation result.

13. A rolling facility comprising: a rolling device including a roll for rolling a metal plate; and a wear condition evaluation device according to claim 11, configured to evaluate a wear condition of the roll.