Steel wire flaw detection device and steel wire diagnostic method

Abstract

The invention provides a steel wire flaw detection device and a steel wire diagnosis method, which can determine the degree of the damaged state and the damaged part of a steel wire without separately setting a threshold value based on the type of the steel wire and setting the difference of the environment. The steel wire flaw detection device is provided with a magnetization mechanism for forming a magnetic path in a predetermined section of a steel wire, and a magnetic sensor capable of detecting a magnetic signal generated from a wire rod of the steel wire, and is also provided with a signal analysis unit for analyzing the signal. The signal analysis unit is configured so as to include a signal collector for collecting the magnetic signals output from the magnetic sensors, and a signal processor for processing the magnetic signals output from the signal collector, and the signal analysis unit detects damage to the steel wire using a plurality of characteristic quantities of each of a plurality of signal waveforms detected by the plurality of magnetic sensors.

Description

Technical Field

[0001] The present invention relates to a flaw detector for measuring the damage state of a metal wire, and in particular to a wire flaw detector device and a wire diagnosis method suitable for wire rope wire fracture flaw detection. Background Art

[0002] The metal wire used in the elevator is a wire rope made by twisting thin steel wires, and is used as a hoisting rope for the elevator car. In addition, in escalators, metal wires are provided inside the resin material of the handrail to maintain strength.

[0003] In such a metal wire, it is necessary to regularly detect the damage state of the wire from the viewpoint of safety.

[0004] Conventionally, a magnetic flux leakage flaw detection method is known as a representative technique for detecting the damage state of a steel wire.

[0005] Furthermore, in the technology for detecting the damage state, the level of the damage state of the wire can be determined by analyzing the detected signal.

[0006] Patent Document 1 discloses a technique for determining the damage state of a wire rope by level based on a level calculated from a correlation between a sensor signal output caused by damage to the wire rope moving in the longitudinal direction and the number of threshold value excesses of the signal output.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-35693 Summary of the invention

[0008] In the wire rope used for the elevator, the thickness and number of strands of the rope used may be changed depending on the model of the elevator.

[0009] Furthermore, in the damaged state of the rope, the damage may vary due to individual differences in rope manufacturing lots, differences in installation conditions such as the weight of the elevator car, etc.

[0010] When wire rope damage is detected, it is effective to identify the cause of the damage in order to improve maintenance measures.

[0011] As one of the causes of damage, for example, when the surface layer of the wire rope is damaged (top wire breakage), wear damage due to excessive contact with the sheave is considered.

[0012] Furthermore, for example, when damage occurs on the inner side of the wire rope (wire breakage at the bottom), it is considered to be caused by poor lubrication due to the shortage or depletion of grease.

[0013] In the determination method of Patent Document 1, a threshold value of signal output is set for each section in the length direction of the wire rope, and the number of signals exceeding the threshold value is counted, thereby classifying the damage state into three levels.

[0014] However, the threshold value in this case needs to be set individually based on the thickness and number of strands of the wire rope. Therefore, if the thickness and number of strands of the wire rope are changed, the threshold value needs to be reset in many cases.

[0015] Furthermore, the location of the damage (broken top wires on the surface layer, broken bottom wires on the inside) cannot be determined using only the threshold value.

[0016] The object of the present invention is to provide a wire flaw detection device and a wire diagnosis method, which can determine the degree of damage state and damaged location of the wire without individually setting thresholds based on the type of wire and the difference in installation environment.

[0017] In addition, the above-mentioned object and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0018] The steel wire flaw detection device of the present invention comprises: a magnetization mechanism, which forms a magnetic circuit in a predetermined interval of the steel wire; and a plurality of magnetic sensors, which can detect the magnetic signal generated from the wire rod of the steel wire. The steel wire flaw detection device detects the damage of the steel wire. The steel wire flaw detection device also comprises a signal analysis unit, which is configured to include: a signal collector, which collects the magnetic signal output from the magnetic sensor; and a signal processor, which processes the magnetic signal output from the signal collector. The signal analysis unit uses a plurality of characteristic quantities of each of a plurality of signal waveforms detected by the plurality of magnetic sensors to detect the damage of the steel wire.

[0019] The steel wire diagnosis method of the present invention uses a steel wire flaw detection device, which includes: a magnetization mechanism, which forms a magnetic circuit in a predetermined interval of the steel wire; and a plurality of magnetic sensors, which can detect magnetic signals generated from the wire rod of the steel wire. The steel wire flaw detection device detects wire damage, and the diagnosis method of the steel wire flaw detection device includes the following steps: for normal steel wire, using a plurality of characteristic quantities of each of a plurality of signal waveforms detected by a plurality of magnetic sensors, a unit space of a plurality of characteristic quantities is pre-made; for the steel wire of the subject, a plurality of characteristic quantities of each of a plurality of signal waveforms detected by a plurality of magnetic sensors are obtained; based on the data of the characteristic quantities of the signal waveforms, the distance between the unit space in the normal steel wire and the steel wire of the subject is detected; and based on the distance, the damage state of the steel wire of the subject is detected.

[0020] According to the wire flaw detection device and wire diagnosis method of the present invention, the damage state (damage level, damage location) of the wire can be determined without individually setting threshold values ​​based on differences in wire type and installation environment.

[0021] Furthermore, by determining the damaged portion of the wire, the cause of the damage can be estimated, thereby making it possible to rationalize maintenance and improve the safety performance of equipment using the wire.

[0022] In addition, other problems, structures, and effects than those described above will become clear through the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram (cross-sectional view) showing a magnetic sensor and a wire rope of a wire rope flaw detection device according to a first embodiment of the present invention.

[0024] Figure 2 It is a functional block diagram showing the structure of the wire flaw detection device according to the first embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram showing the types of feature quantities of a signal waveform.

[0026] Figure 4 This is a flowchart of the determination process regarding the normality and abnormality of the wire rope according to the first embodiment of the present invention.

[0027] Figure 5 This is a flowchart of a process for determining a location where a wire breakage occurs in a damaged wire rope according to the first embodiment of the present invention.

[0028] Figure 6 This is a diagram showing an example of the relationship between the value of the signal feature amount and the normal and abnormal levels according to the first embodiment of the present invention.

[0029] Figure 7 This is a diagram showing an example of the relationship between the value of the signal feature amount and the damaged part of the wire according to the first embodiment of the present invention.

[0030] Figure 8 It is a diagram showing an example of display of determination results according to the first embodiment of the present invention.

[0031] Fig. 9 It is a schematic diagram showing the arrangement of a wire and a sensor according to a second embodiment of the present invention.

[0032] Fig.10 It is a functional block diagram showing the structure of a wire flaw detection device according to a second embodiment of the present invention.

[0033] Fig.11 This is a flowchart of the determination process regarding normality and abnormality of the wire according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0034] Hereinafter, the embodiments and examples of the present invention will be described using articles or drawings. However, the structures, materials, and other specific structures shown in the present invention are not limited to the embodiments and examples proposed herein, and can be appropriately combined and improved within the scope of not changing the main purpose. In addition, elements that are not directly related to the present invention are omitted from the drawings.

[0035] The wire flaw detector of the present invention is provided with a magnetizing mechanism for forming a magnetic path in a predetermined section of the wire and a plurality of magnetic sensors capable of detecting magnetic signals generated from the wire rod of the wire, and is a wire flaw detector for detecting damage to the wire.

[0036] In addition, the wire flaw detection device of the present invention further includes a signal analysis unit, which is configured to include a signal collector for collecting magnetic signals output from the magnetic sensor and a signal processor for processing the magnetic signals output from the signal collector.

[0037] Furthermore, in the wire flaw detection device of the present invention, the signal analysis unit detects flaws in the wire using a plurality of feature quantities of each of a plurality of signal waveforms detected by a plurality of magnetic sensors.

[0038] According to the steel wire flaw detection device of the present invention, the signal analysis unit uses multiple characteristic quantities of each of the multiple signal waveforms detected by the multiple magnetic sensors to detect the damage of the steel wire. Therefore, there is no need to separately set different thresholds based on the type of steel wire and the installation environment, and the damage state (damage level, damage location) of the steel wire can be determined.

[0039] Furthermore, since the cause of the damage can be estimated by determining the damaged portion of the wire, it is possible to rationalize maintenance and improve the safety performance of equipment using the wire, such as elevators.

[0040] The steel wire diagnosis method of the present invention is a steel wire diagnosis method using a steel wire flaw detector, which has a magnetization mechanism that forms a magnetic circuit in a predetermined section of the steel wire and a plurality of magnetic sensors that can detect magnetic signals generated from the wire rod of the steel wire, and detect damage to the steel wire.

[0041] Furthermore, the steel wire diagnosis method of the present invention includes the following steps: for a normal steel wire, using a plurality of characteristic quantities of each of a plurality of signal waveforms detected by a plurality of magnetic sensors, a unit space of a plurality of characteristic quantities is pre-prepared; for a steel wire of an object, obtaining a plurality of characteristic quantities of each of a plurality of signal waveforms detected by a plurality of magnetic sensors; based on data of the characteristic quantities of the signal waveforms, detecting the distance between the unit space in the normal steel wire and the steel wire of the object; and based on the distance, detecting the damage state of the steel wire of the object.

[0042] According to the steel wire diagnosis method of the present invention, since the damage state of the steel wire is detected using multiple characteristic quantities of each of the multiple signal waveforms detected by multiple magnetic sensors, there is no need to individually set different thresholds based on the type of steel wire and the installation environment, and the damage state of the steel wire (damage level, damage location) can be determined.

[0043] In addition, since the distance between the unit space in the normal steel wire and the steel wire of the subject is detected and the damage state of the steel wire of the subject is detected based on the distance, there is no need to individually set different thresholds based on the type of wire and the setting environment, thereby making it easier and more reliably to determine the damage level and damage location of the steel wire of the subject.

[0044] In the above-mentioned steel wire flaw detection device, it can be configured that the signal analysis unit calculates the distance between the unit space and the multiple characteristic quantities of the multiple signal waveforms detected by multiple magnetic sensors based on a unit space created based on multiple characteristic quantities of the signal waveform obtained by pre-measuring a normal steel wire, and detects the degree of damage to the steel wire of the object to be inspected based on the distance.

[0045] When this structure is used, based on the unit space, the distance between the unit space and multiple characteristic quantities of multiple signal waveforms detected by multiple magnetic sensors is calculated, and the degree of damage to the steel wire of the subject is detected based on the distance. Therefore, the damage level and damage location of the steel wire of the subject can be determined more easily and reliably.

[0046] In the above-mentioned steel wire flaw detection device, it can also be configured that, when the signal analysis unit determines that the steel wire of the object to be inspected is damaged, it calculates the distance between the unit space created based on the multiple characteristic quantities of the signal waveform obtained by pre-measuring the normal steel wire and the multiple characteristic quantities of the signal waveform detected by the multiple magnetic sensors of the steel wire of the object to be inspected, and compares the distance with a threshold value based on the distance, thereby detecting the damaged part of the steel wire of the object to be inspected.

[0047] With this configuration, the damaged portion of the wire of the subject is detected by comparing the distance to the unit space with a threshold value based on the distance, so that the damaged portion of the wire of the subject can be determined more easily and more reliably.

[0048] In the above-mentioned wire flaw detection device, it can also be configured that when the signal analysis unit determines that the steel wire of the test object is damaged, multiple feature quantities including at least a feature quantity representing kurtosis are used as multiple feature quantities to detect the damaged part of the steel wire of the test object.

[0049] Furthermore, the signal analysis unit may be configured to detect a damaged portion of the wire of the subject using any combination of kurtosis and amplitude, kurtosis and half-value width, and kurtosis and area as a plurality of feature quantities.

[0050] With these configurations, a plurality of feature quantities including a feature quantity indicating kurtosis are used, and therefore, it is particularly possible to easily determine where damage has occurred.

[0051] In the above-mentioned wire flaw detection device, it can be configured so that the signal analysis unit uses the Mahalanobis distance as the distance.

[0052] With this configuration, the Mahalanobis distance is used as the distance to the unit space, so that the damage level and damaged portion of the wire of the subject can be determined more easily.

[0053] In the above-mentioned steel wire diagnosis method, the step of determining the damage state of the steel wire of the subject can further include the following steps: detecting the degree of damage of the steel wire of the subject; and detecting the damaged part of the steel wire of the subject. In the step of detecting the damaged part of the steel wire of the subject, a plurality of feature quantities including at least a feature quantity representing the kurtosis are used.

[0054] Furthermore, in the wire diagnosis method described above, in the step of detecting a damaged portion of the wire of the subject, any combination of kurtosis and amplitude, kurtosis and half-value width, or kurtosis and area may be used.

[0055] With these configurations, a plurality of feature quantities including a feature quantity indicating kurtosis are used, and therefore, it is particularly possible to easily determine where damage has occurred.

[0056] In the above-mentioned wire diagnosis method, it is possible to configure such that, in the step of detecting the distance, Mahalanobis distance is used as the distance.

[0057] With this configuration, the Mahalanobis distance is used as the distance to the unit space, so that the damage level and damaged portion of the wire of the subject can be determined more easily.

[0058] The wire flaw detection device and wire diagnosis method of the present invention can be applied to inspect the flaws of the wire in various devices using the wire.

[0059] For example, it can be applied to a wire rope of a hoisting rope of a car of an elevator, a wire inside a handrail of an escalator, and the like.

[0060] Hereinafter, specific embodiments of the wire flaw detection device and the wire diagnosis method of the present invention will be described.

[0061] (First Embodiment)

[0062] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

[0063] In this embodiment, the steel wire flaw detection device and the steel wire diagnosis method of the present invention are applied to a steel wire rope used in an elevator.

[0064] The wire rope used in elevators is formed by twisting multiple thin wires into strands, and the strands are twisted around a core to form a bundle.

[0065] A steel wire rope made by twisting together wires of magnetic metal materials is used as the hoisting rope of the elevator car.

[0066] The wire rope of an elevator used as a moving rope undergoes time-dependent changes such as deterioration such as bending fatigue, wear, and corrosion over the course of use, and therefore requires regular inspection and examination.

[0067] Visual inspection is effective in detecting deterioration that is a noticeable change in appearance, such as rust or corrosion, but it is difficult for inspectors to detect variations in inspection accuracy or abnormalities that occur inside the wire rope.

[0068] Therefore, in the safety monitoring technology of the wire rope, it is effective to use a leakage flux flaw detection method that detects the deterioration state of the wire rope based on the leakage flux generated from the wire rope. The leakage flux flaw detection method is a method of exciting the wire rope and detecting the generated leakage flux with a magnetic sensor.

[0069] In a measuring device using a magnetic flux leakage flaw detection method (hereinafter referred to as a magnetic flux leakage flaw detection device), a magnetizing mechanism for magnetizing a wire rope is provided, and a magnet is attached to the magnetizing mechanism.

[0070] The leakage flux flaw detection device for wire rope has a structure in which when the wire rope contacts the magnetizing mechanism, the magnetic flux flows back between the wire rope and the magnetizing mechanism through the magnetic field emitted by the magnet, forming a magnetic circuit.

[0071] If a wire rope forming a magnetic path is damaged by wire breakage, the flow of magnetic flux is blocked and the magnetic flux leaks to the surface of the wire rope. By detecting the leakage magnetic flux with a magnetic sensor, the wire breakage of the wire rope can be detected.

[0072] The magnetic flux leakage flaw detection device of the present embodiment described below can detect the level of the damage state based on the occurrence frequency of wire breakage and the type of wire breakage.

[0073] In addition, in this embodiment, the leakage flux flaw detector is referred to as a "wire rope flaw detector" for description.

[0074] Figure 1 It is a schematic diagram (cross-sectional view) showing a magnetic sensor and a wire rope of a wire rope flaw detection device according to a first embodiment of the present invention.

[0075] like Figure 1 As shown, a wire rope flaw detection device 1 (see Figure 2 ) of the sensor unit 20 having multiple magnetic sensors 3.

[0076] Figure 1 The illustrated steel wire rope 2 has eight strands 23, and the entirety including the eight strands 23 is twisted into one. In addition, the steel wire rope 2 composed in this way is only an example of an inspection object of the steel wire rope flaw detection device 1 of this embodiment, and the steel wire rope flaw detection device 1 of this embodiment can also be used to diagnose steel wire ropes with different numbers of strands.

[0077] The steel wire rope 2 and the strands 23 are composed of a plurality of wires 24. If there is a broken portion of the wire 24, the steel wire flaw detection device 1 is required to reliably detect the broken portion.

[0078] In addition, the wire 24 is broken depending on the location. When it occurs on the outer peripheral side of the strand 23, it is called the top wire break 25 of the wire 24, and when it occurs in the middle of the adjacent strand, it is called the bottom wire break 26 of the wire 24. That is, the bottom wire break 26 refers to the wire break of the wire 24 at the middle of the outermost peripheral part and the innermost peripheral part of the strand 23 in the circumferential direction of the strand 23, or at the location where the adjacent strands 23 contact each other.

[0079] Figure 1 The magnetic sensors 3 shown are arranged in plurality on the circumference close to the steel wire rope 2 .

[0080] In addition, as types of the magnetic sensor 3, detection coils and Hall elements are representative, but for example, a TMR (Tunnel Magneto Resistive) sensor, an AMR (Anisotropic Magneto Resistive) sensor, or a GMR (Giant Magneto Resistive effect) sensor may also be used.

[0081] The arrangement of the magnetic sensors 3 constituting the sensor unit 20 adopts an optimal mode that varies depending on the type of the magnetic sensors 3 .

[0082] The magnetic sensors 3 are arranged to efficiently detect the broken part of the wire 24 with a minimum number of magnetic sensors 3 , and preferably a plurality of magnetic sensors 3 are arranged around the outer periphery of the wire rope 2 at a predetermined interval (pitch).

[0083] Figure 2 It is a functional block diagram showing the structure of the wire rope flaw detection device 1 according to the first embodiment of the present invention.

[0084] like Figure 2 As shown, the wire rope flaw detection device 1 includes a magnetizing mechanism 30 , a sensor unit 20 , a magnetic sensor circuit (magnetic sensor circuit unit) 5 , a signal analysis unit 7 , a data display unit 8 , and a data input unit 9 .

[0085] The data input unit 9 and the data display unit 8 include a general-purpose computer (PC) connected to a power source 10 and a control circuit 11 , and a user operates the computer to control the wire rope flaw detection device 1 .

[0086] The control circuit 11 controls the magnetic sensor circuit 5 and the signal analysis unit 7 .

[0087] The magnetizing mechanism 30 forms a magnetic path in a predetermined section in the longitudinal direction of the steel wire. The magnetizing mechanism 30 can be configured to magnetize the steel wire by a DC magnetic field using a permanent magnet or a non-contact AC magnetic field using an excitation coil.

[0088] The magnetic sensor circuit 5 includes a magnetic signal amplifier (magnetic signal amplifier unit) 12 and a filter circuit (filter circuit unit) 13. The magnetic signal amplifier 12 amplifies the output signal from the magnetic sensor 3. The filter circuit 13 performs a general analog filter process on the output signal amplified by the magnetic signal amplifier 12, and outputs an analog signal. In the analog filter process, noise components including noise of commercial frequency are removed, and only signals in the desired frequency domain are passed.

[0089] In this way, the magnetic sensor circuit 5 performs analog processing on the magnetic detection signal output from the magnetic sensor 3 , and outputs the analog magnetic signal to the signal analysis unit 7 .

[0090] The signal analysis unit 7 is composed of an A / D converter (A / D conversion unit) 16, a signal collector (signal collection unit) 17, and a signal processor (signal processing) 18. The A / D converter 16 converts the analog magnetic signal output from the magnetic sensor circuit 5 into a digital signal, and outputs it to the signal collector 17. The signal processor 18 includes a single-chip microcomputer or a single-board computer, etc.

[0091] The signal processor 18 reads out and executes a program stored in a memory or a storage device through a CPU (Central Processing Unit), thereby storing the digital magnetic signal output from the A / D converter 16 in the signal collector 17 .

[0092] The processing by the signal analysis unit 7 can be realized by program processing in the signal processor 18 , and the data display unit 8 and the data input unit 9 can also be set as related devices of the signal processor 18 such as a keyboard and a liquid crystal display.

[0093] Next, an overview of the analysis process for determining whether a wire of a wire rope is broken in the signal analysis unit 7 of the wire rope flaw detector 1 will be described, and the processing procedure will be described in detail with reference to the drawings.

[0094] The leakage magnetic flux of the wire rope 2 is detected by the magnetic sensor 3 and, as described above, converted into a digital signal by the A / D converter 16 of the signal analysis unit 7. In the case where the wire rope 2 is damaged, the leakage magnetic flux signal caused by the wire break is converted into a digital signal. In addition, in a normal wire rope 2 where no wire break occurs, only the strand signal originating from the unevenness of the strand 23 is detected.

[0095] Furthermore, the signal originating from the wire breakage and the strand signal detected in a normal wire rope have different characteristic quantities of signal waveforms, respectively.

[0096] Figure 3 This is a schematic diagram showing the types of feature quantities of a signal waveform.

[0097] Specifically, as the characteristic quantity of the signal waveform (hereinafter also referred to as “signal characteristic quantity”), Figure 3 As shown, the amplitude 100, the half-value width 101, the area 102, the effective value 103, the kurtosis 104, the skewness 105, and the crest factor 106 which is the ratio of the amplitude 100 to the effective value 103 can be listed.

[0098] Since the signal resulting from wire breakage occurring in an abnormal wire rope and the strand signal detected in a normal wire rope have different signal feature quantities, it is possible to determine normality and abnormality by utilizing the difference in signal feature quantities.

[0099] However, if the absolute values ​​of the signal features are used, differences will occur depending on the type and individual differences of the wire ropes, and therefore clustering processing based on multivariate analysis is required.

[0100] A representative method of cluster analysis is the analysis method using the Mahalanobis distance. Specifically, when a multivariate x is used to represent the signal value within a group, if μ is used to represent the average value of each variable in the group and Σ is used to represent the covariance matrix of the group, then the Mahalanobis distance Dm(x) with a specific variable is defined by the following formula (1).

[0101] [Formula 1]

[0102]

[0103] In addition, in the MT (Mahayana Taguchi) method, which is one of the conventional analysis methods, a normal sample is set as a unit space, and the Mahalanobis distance with the test object is analyzed to determine the abnormality of the test object.

[0104] In addition, such a cluster analysis method is not limited to the Mahalanobis distance, and methods such as the Euclidean distance, the Manhattan distance, the Chebyshev distance, and the Minkowski distance may also be used.

[0105] In this embodiment, using Figure 3 A plurality of feature quantities among the feature quantities of the plurality of signal waveforms shown are subjected to clustering processing based on multivariate analysis.

[0106] As the plurality of feature amounts, a combination of two or more arbitrary feature amounts can be used.

[0107] It is preferable to use, as a plurality of feature quantities, at least Figure 3 More preferably, it includes Figure 3 Any combination of kurtosis 104 and amplitude 100, kurtosis 104 and half-value width 101, kurtosis 104 and area 102 shown.

[0108] In this way, by using a plurality of feature quantities including the kurtosis 104, it is possible to easily identify the position where the wire 24 of the wire rope 2 has broken.

[0109] In addition, in this embodiment, the signal feature quantity obtained in advance from a normal wire rope is used as a unit space, and the distance (Mahalanobis distance, etc.) to the signal feature quantity of the inspected wire rope is calculated. In the case of damage, the damage level is determined based on the degree of distance from the unit space.

[0110] Figure 4 This is a flowchart of the determination process regarding the normality and abnormality of the wire rope according to the first embodiment of the present invention.

[0111] according to Figure 4 First, in step S11, according to the control of the control circuit 11, the magnetic signal of the new or normal steel wire rope is obtained by the magnetic sensor 3, and its signal characteristic quantity a and signal characteristic quantity b are analyzed.

[0112] Next, in step S12, the signal feature a and signal feature b of the new and normal wire ropes analyzed in step S11 are created as unit spaces in the signal processor 18 and stored.

[0113] Next, in step S13, the signal of the wire rope to be inspected is acquired, and then the signal feature amount a and the signal feature amount b of the wire rope to be inspected are acquired from the signal.

[0114] Next, in step S14, it is determined whether the signal characteristic a and signal characteristic b of the inspected wire rope are within the reference range. Specifically, the unit space of the signal characteristic of the normal wire rope pre-stored in step S12 is compared with the distance (Mahalanobis distance, etc.) of the points based on the signal characteristic a and signal characteristic b of the inspected wire rope and the reference range.

[0115] In step S14, if the distance is within the reference range, the process proceeds to step S15. In step S15, the inspected wire rope is determined to be a normal product A, and is displayed as normal in the data display unit 8.

[0116] In step S14, if the distance is outside the reference range, the process proceeds to step S16, and the abnormality level B or C is determined based on the distance value, and the abnormality is displayed in the data display unit 8, and the process proceeds to step S17. At this time, the abnormality level (B or C) is displayed in the data display unit 8 together with the abnormality display.

[0117] In step S17, a process of determining a location where a wire breakage has occurred in the wire rope determined to have abnormality degree B or C is performed.

[0118] In this way, the determination as to whether the wire rope is normal or abnormal is performed, and the determination result is displayed in the data display unit 8 .

[0119] In addition, as Figure 4 As the signal feature amount a and the signal feature amount b shown, any two types of feature amounts can be used.

[0120] Figure 5 This is a flowchart of the process of determining the location of wire breakage in the damaged wire rope according to the first embodiment of the present invention. Figure 4 The processing method in the determination of step S17 is shown.

[0121] according to Figure 5 First, in step S21, the signal characteristic amount c and the signal characteristic amount d of the wire rope to be inspected are obtained. Then, the obtained signal characteristic amount c and the signal characteristic amount d are analyzed.

[0122] Next, in step S22, it is determined whether the signal feature c and the signal feature d are above the reference range. Specifically, the unit space based on the pre-stored signal feature c and the signal feature d of a normal wire rope is compared with the distance of the point based on the signal feature c and the signal feature d and the reference range of the distance.

[0123] In step S22, if the distance is within the reference range, the process proceeds to step S23, in which the data display unit 8 determines that the wire material displayed as bottom wire breakage is broken.

[0124] In step S22, if the distance is greater than or equal to the reference range, the process proceeds to step S24, in which the data display unit 8 determines that the wire rod indicated as the top wire break is broken.

[0125] In this way, the occurrence position of the wire breakage of the inspection object wire rope is determined.

[0126] In addition, as Figure 5 The signal characteristic c and signal characteristic d shown are preferably used in Figure 4 The combination of the characteristic quantities used in the signal characteristic quantity a and the signal characteristic quantity b shown in the figure and the combination of at least one of the characteristic quantities being different. A combination of different characteristic quantities of both sides can be used, or a combination of different characteristic quantities of one side and the same characteristic quantity of the other side can be used. In this way, the unit space and distance of the normal wire rope can be respectively suitable for the detection of the damage level and the determination of the damage occurrence location.

[0127] In addition, it is preferred that at least one of the signal feature amount c and the signal feature amount d be set to kurtosis. It is more preferred that the signal feature amount c and the signal feature amount d be set to any combination of kurtosis and amplitude, kurtosis and half-value width, kurtosis and area. In this way, by setting at least one of the signal feature amount c and the signal feature amount d to kurtosis, it is possible to easily determine the location where the damage occurs.

[0128] The wire rope flaw detection device 1 of this embodiment includes a magnetization mechanism 30 for magnetizing the wire rope 2 and a plurality of magnetic sensors 3 capable of detecting magnetic signals generated from the wire rods 24 of the wire rope 2, and also includes a signal analysis unit 7, which is constructed to include a signal collector 17 for collecting the magnetic signals output from the magnetic sensors 3 and a signal processor 18 for obtaining signal characteristic quantities of the magnetic signals output from the signal collection unit 17.

[0129] The signal analysis unit 7 stores a plurality of signal features previously acquired from a normal wire rope as a unit space, and detects the damage level of the test wire rope based on the distance (Mahalanobis distance, etc.) from the plurality of signal features acquired from the test wire rope.

[0130] Furthermore, the signal analysis unit 7 calculates distances (such as Mahalanobis distance) between a plurality of signal feature quantities and a unit space in the damaged wire rope to determine the location where the damage has occurred.

[0131] Figure 6 This is a diagram showing an example of the relationship between the values ​​of the signal feature amount a and the signal feature amount b and the levels of normality and abnormality according to the first embodiment of the present invention.

[0132] Specifically, for example, the signal feature of a normal product or a wire rope classified as judgment A is used as the unit space 40, and the wire rope is classified into normal and abnormal levels according to the reference value of the Mahalanobis distance in the values ​​of each signal feature a and signal feature b.

[0133] When the values ​​of the signal feature a and the signal feature b are within the unit space 40, Figure 4 It is determined to be normal in step S14.

[0134] When the values ​​of the signal feature a and the signal feature b are outside the unit space 40, Figure 4 In step S14, it is determined that there is an abnormality, and the Mahalanobis distance from the unit space 40 in the values ​​of the signal feature a and the signal feature b is compared with the reference value of the Mahalanobis distance. Thus, it is classified into the category 41 of the determination B or the category 42 of the determination C.

[0135] then, Figure 7 This is a diagram showing an example of the values ​​of the signal feature amount c and the signal feature amount d and the damaged portion of the wire according to the first embodiment of the present invention.

[0136] Specifically, for example, Figure 6 The steel wire rope of the classification 41 of the judgment B and the classification 42 of the judgment C is judged by the Mahalanobis distance in the values ​​of the respective signal feature quantities c and d as the top broken wire 25 generated on the periphery and the bottom broken wire 26 generated on the inside.

[0137] Here, since the distance between the damage location and the magnetic sensor 3 and the distribution of the leakage magnetic field differ depending on the damage location, for example, a change in a signal characteristic quantity such as kurtosis may be considered.

[0138] Then, the top broken wire classification 44 and the bottom broken wire classification 43 are determined based on the difference in the Mahalanobis distance between the signal feature amount c and the signal feature amount d.

[0139] The result of the determination is displayed on the data display unit 8. The data display unit 8 is, for example, a liquid crystal display connected via an output interface, and displays the processing result executed by the signal analysis unit 7 as an analysis result display screen.

[0140] Figure 8 It is a diagram showing an example of display of determination results according to the present embodiment.

[0141] Figure 8 A specific example of the analysis result display screen of the data display unit 8 is shown. The analysis result display screen displays, for example, whether there is an abnormality in the signal waveform, the type of broken wire (bottom broken wire or top broken wire), the number of broken wires, the model number, and the analysis date and time.

[0142] Although not shown in the figure, the standard of the replacement time of the wire rope estimated based on the determination result may be displayed on the analysis result display screen.

[0143] According to the present embodiment described above, in the wire rope flaw detection device 1, the level (damage degree) of the damage state of the wire rope 2 and the damaged portion can be determined by using multivariate analysis based on distances such as Mahalanobis distance.

[0144] Furthermore, by using multivariate analysis based on distances such as Mahalanobis distance, the level of the damage state of the wire rope 2 and the damaged location can be determined without individually setting a threshold value based on differences in product types of the wire rope 2 used in the elevator.

[0145] Furthermore, according to the present embodiment, by determining the damaged portion of the wire rope 2, the cause of the damage can be estimated.

[0146] In addition, since the distance between the damage location and the magnetic sensor 3 and the distribution of the leakage magnetic field differ depending on the damage location, changes in signal characteristic quantities such as kurtosis may be considered.

[0147] Therefore, by using multiple feature quantities including kurtosis as Figure 5 as well as Figure 7 The signal feature c and the signal feature d can easily determine the location where the damage occurs.

[0148] (Second Embodiment)

[0149] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

[0150] In this embodiment, the wire flaw detection device and wire rope diagnosis method of the present invention are applied to a wire rope used in a handrail of an escalator.

[0151] In an escalator, a handrail is provided which rotates in conjunction with the steps and is provided for the purpose of preventing passengers from falling.

[0152] The handrail is covered with a resin material such as polyurethane, and a plurality of steel wires are provided inside the resin material to maintain strength.

[0153] When the steel wires are twisted and then broken due to the deterioration of the steel wires over time, the broken ends of the steel wires may fly out of the handrails, which is dangerous. Therefore, it is necessary to regularly check whether the steel wires inside the handrails are twisted or broken.

[0154] The condition of the steel wire cannot be monitored from the appearance of the handrail, but by using the magnetic flux leakage flaw detection method, which is one of the non-destructive inspection methods, it is possible to measure the twisting and breaking of the steel wire inside.

[0155] Fig. 9 It is a diagram showing the arrangement of the wire and the sensor according to the present embodiment.

[0156] First, if Fig. 9As shown, a sensor unit 60 is arranged at a position opposite to the steel wire 53 to be inspected. The sensor unit 60 is composed of a pair of magnetizing mechanisms (a first excitation coil 50 and a second excitation coil 51) and a magnetic sensor (detection coil) 52 arranged in the middle of the two excitation coils 50 and 51, and is arranged in a row along the extension direction of the steel wire 53.

[0157] The first excitation coil 50 and the second excitation coil 51 generate alternating magnetic fields in opposite directions to each other, and non-contact magnetize the wire 53. At this time, the magnetic sensor 52 detects a magnetic signal based on the magnetic field formed by the first excitation coil 50 and the second excitation coil 51.

[0158] When the normal steel wire 53 is magnetized by the opposing first exciting coil 50 and second exciting coil 51 , the magnetic fields input to the magnetic sensor 52 are opposite to each other and are therefore canceled out and are not detected as magnetic signals.

[0159] On the other hand, when twisting or breaking occurs in the wire 53, leakage magnetic flux is generated, which causes deviation in the magnetic field input to the magnetic sensor 52 and is detected as a magnetic signal.

[0160] In addition, the magnetic signal of the leakage magnetic flux caused by the twisting and breaking of the steel wire 53 has the same characteristics as those of the first embodiment. Figure 3 The signal feature quantities 100 to 105 shown are the same signal feature quantities. Therefore, the degree of twisting and breaking of the steel wire 53 can be determined by multivariate analysis based on distance (Mahalanobis distance, etc.).

[0161] exist Fig. 9 , one set of excitation coils 50 , 51 and magnetic sensor (detection coil) 52 is shown, but a plurality of sets of excitation coils 50 , 51 and magnetic sensor (detection coil) 52 are actually used.

[0162] Furthermore, multiple sets of excitation coils 50, 51 and magnetic sensors 52 are connected to Fig. 9 The vertical direction of the paper, Fig. 9 The wire 53 is arranged in a row in the left-right direction (for example, refer to Japanese Patent Publication No. 2018-4555, Japanese Patent Publication No. 2021-134081, etc.). As a result, a large range of inspections of the wire 53 can be performed by multiple groups of multiple magnetic sensors 52.

[0163] In addition, the normal measurement of the wire 53 is actually affected by the difference in the installation environment of the wire 53. For example, due to the mixing of disturbance noise such as vibration and a marker signal for position detection, a specific magnetic signal is detected.

[0164] In the present embodiment, a magnetic signal including a disturbance signal accompanying measurement of a normal wire 53 is set as a unit space.

[0165] Fig.10 It means connection Fig. 9 A functional block diagram of the structure of a wire flaw detection device 61 of an embodiment of the present invention which is constructed by using a sensor portion 60.

[0166] like Fig.10 As shown, the wire flaw detection device 61 includes a pair of magnetizing mechanisms (first excitation coil and second excitation coil) 50, 51, a magnetic sensor 52, a magnetic sensor circuit (magnetic sensor circuit unit) 65, a signal analysis unit 67, a data display unit 88 and a data input unit 69.

[0167] The data input unit 69 and the data display unit 88 include a general-purpose computer (PC) connected to the power supply 70 and the control circuit 71 , and the user controls the wire flaw detection device 61 by operating the computer.

[0168] The control circuit 71 controls the magnetic sensor circuit 65 and the signal analysis unit 67 .

[0169] The magnetizing mechanisms 50 and 51 form a non-contact magnetic path in a predetermined section in the longitudinal direction of the wire 53. The magnetizing mechanisms 50 and 51 magnetize the wire 53 by an AC magnetic field generated by the magnetizing mechanisms 50 and 51 in response to an AC frequency input from the control circuit 71 to the magnetizing mechanisms 50 and 51.

[0170] The magnetic sensor circuit 65 has a magnetic signal amplifier (magnetic signal amplifier unit) 62 and a filter circuit (filter circuit unit) 63. The magnetic signal amplifier 62 amplifies the output signal from the magnetic sensor 52. At this time, the AC frequency input from the control circuit 71 to the magnetizing mechanisms 50 and 51 is also input to the magnetic signal amplifier 62 as a reference signal, and synchronized with the output signal from the magnetic sensor 52. The filter circuit 63 performs a general analog filtering process on the output signal amplified by the magnetic signal amplifier 62, and outputs an analog signal. In the analog filtering process, the noise component including the noise of the commercial frequency is removed, and only the signal of the desired frequency domain is passed.

[0171] In this way, the magnetic sensor circuit 65 performs analog processing on the magnetic detection signal output from the magnetic sensor 52 , and outputs the analog magnetic signal to the signal analysis unit 67 .

[0172] The signal analysis unit 67 is composed of an A / D converter (A / D conversion unit) 76, a signal collector (signal collection unit) 77, and a signal processor (signal processing) 78. The A / D converter 76 converts the analog magnetic signal output from the magnetic sensor circuit 65 into a digital signal, and outputs it to the signal collector 77. The signal processor 78 includes a single-chip microcomputer or a single-board computer.

[0173] The signal processor 78 reads out and executes a program stored in a memory or a storage device by a CPU (Central Processing Unit), thereby storing the digital magnetic signal output from the A / D converter 76 in the signal collector 77 .

[0174] The processing by the signal analysis unit 67 can be realized by program processing in the signal processor 78 , and the data display unit 88 and the data input unit 69 can also be set as related devices of the signal processor 88 such as a keyboard and a liquid crystal display.

[0175] Fig.11 This is a flowchart of the determination process regarding normality and abnormality of the wire according to the second embodiment of the present invention.

[0176] according to Fig.11 First, in step S31, a magnetic signal of a new or normal steel wire is obtained by the magnetic sensor 52, and its signal characteristic value e and signal characteristic value f are analyzed.

[0177] Next, in step S32 , the signal feature amount e and the signal feature amount f of the new steel wire and the normal steel wire analyzed in step S31 are created as a unit space in the signal processor 88 and stored.

[0178] Next, in step S33, the signal of the test object wire is acquired, and then the signal feature amount e and the signal feature amount f are acquired from the signal.

[0179] Next, in step S34, it is determined whether the signal feature e and the signal feature f are within the reference range. Specifically, the distance (Mahalanobis distance, etc.) between the unit space of the normal steel wire and the point based on the signal feature e and the signal feature f stored in advance in step S32 is compared with the reference range.

[0180] In step S34 , if the distance is within the reference range, the process proceeds to step S35 , in which the inspection wire is determined to be a normal product A, and is displayed as normal in the data display unit 88 .

[0181] In step S34 , if the distance is outside the reference range, the process proceeds to step S36 , where an abnormality level B or C is determined based on the distance value, and the data display unit 88 displays that an abnormality exists.

[0182] Next, in step S37, the result of determination as normality A, abnormality degree B or C is displayed on the data display unit 88, and the processing ends.

[0183] In this way, the determination as to whether the wire is normal or abnormal is performed, and the determination result is displayed in the data display unit 88 .

[0184] In addition, as Fig.11 As the signal feature amount e and the signal feature amount f shown, any two types of feature amounts can be used.

[0185] According to the present embodiment described above, in the wire flaw detector 61, the level (degree of damage) of the damage state of the wire 53 can be determined by using multivariate analysis based on distances such as Mahalanobis distance.

[0186] Furthermore, by using multivariate analysis based on distances such as Mahalanobis distance, the level of the damage state of the wire 53 can be determined without individually setting a threshold value based on the difference in the installation environment of the wire 53 .

[0187] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not limited to necessarily having all the described structures.

[0188] (Variation Example)

[0189] In each of the above-described embodiments, two feature quantities are used as a plurality of feature quantities, the distance from the unit space is calculated, and multivariate analysis based on the distance is performed.

[0190] In the present invention, it is also possible to use three or more feature quantities to calculate the distance from the unit space and perform multivariate analysis based on the distance to detect the damage state of the steel wire. For example, when the Mahalanobis distance is used as the distance, in the above formula (1), even if the number of variables of the multivariate x is set to three or more, the Mahalanobis distance from the unit space can be calculated.

[0191] Industrial Applicability

[0192] In safety monitoring of elevators, the present invention can be adopted as a diagnostic method for inspecting a wire rope flaw detector for a hoisting rope of an elevator and a wire flaw detector used in a handrail of an escalator.

[0193] Explanation of symbols

[0194] 1…wire rope flaw detection device, 2…wire rope, 3, 52…magnetic sensor, 5, 65…magnetic sensor circuit, 7, 67…signal analysis unit, 8, 88…data display unit, 9, 69…data input unit, 17, 77…signal collector, 18, 78…signal processor, 20, 60…sensor unit, 23…strand, 24…wire material, 25…top broken wire, 26…bottom broken wire, 50…first excitation coil (magnetization mechanism), 51…second excitation coil (magnetization mechanism), 53…steel wire, 61…wire flaw detection device.

Claims

1. A wire flaw detection device, comprising: a magnetizing mechanism, which forms a magnetic circuit in a predetermined section of the steel wire; and a plurality of magnetic sensors, which can detect magnetic signals generated from the wire rod of the steel wire, wherein the wire flaw detection device detects damage to the steel wire, characterized in that: The wire flaw detection device further includes a signal analysis unit, which includes: a signal collector, which collects the magnetic signal output from the magnetic sensor; and a signal processor, which processes the magnetic signal output from the signal collector. The signal analysis unit detects damage to the wire using a plurality of feature quantities of each of a plurality of signal waveforms detected by the plurality of magnetic sensors.

2. The wire flaw detection device according to claim 1, characterized in that: The signal analysis unit calculates the distance between the unit space and the multiple characteristic quantities of the multiple signal waveforms detected by the multiple magnetic sensors based on a unit space created based on multiple characteristic quantities of the signal waveform obtained by pre-measuring a normal steel wire, and detects the degree of damage to the steel wire of the subject based on the distance.

3. The wire flaw detection device according to claim 2, characterized in that: When the signal analysis unit determines that the steel wire of the subject is damaged, the signal analysis unit calculates the distance between the unit space created based on the multiple characteristic quantities of the signal waveform obtained by pre-measuring the normal steel wire and the multiple characteristic quantities of the signal waveform of the steel wire of the subject detected by the multiple magnetic sensors, and detects the damaged part of the steel wire of the subject by comparing the distance with a threshold value based on the distance.

4. The wire flaw detection device according to claim 3, characterized in that: When the signal analysis unit determines that the wire of the subject is damaged, the signal analysis unit detects a damaged portion of the wire of the subject using a plurality of feature quantities including at least a feature quantity indicating kurtosis as the plurality of feature quantities.

5. The wire flaw detection device according to claim 4, characterized in that: When the signal analysis unit determines that the steel wire of the subject is damaged, the signal analysis unit uses any combination of kurtosis and amplitude, kurtosis and half-value width, and kurtosis and area as the multiple feature quantities to detect the damaged part of the steel wire of the subject.

6. The wire flaw detection device according to claim 2, characterized in that: The signal analysis unit uses the Mahalanobis distance as the distance.

7. A method for diagnosing a steel wire using a steel wire flaw detector, the steel wire flaw detector comprising: a magnetizing mechanism that forms a magnetic circuit in a predetermined section of the steel wire; and a plurality of magnetic sensors that can detect magnetic signals generated from the wire rod of the steel wire, the steel wire flaw detector detecting damage to the steel wire, characterized in that: The wire diagnosis method comprises the following steps: For a normal steel wire, using a plurality of feature quantities of each of a plurality of signal waveforms detected by the plurality of magnetic sensors, a unit space of the plurality of feature quantities is prepared in advance; For the steel wire of the subject, a plurality of characteristic quantities of each of the plurality of signal waveforms detected by the plurality of magnetic sensors are obtained; detecting the distance between the unit space in the normal wire and the wire of the object based on the data of the characteristic amount of the signal waveform; and Based on the distance, a damage state of the steel wire of the object is detected.

8. The wire diagnosis method according to claim 7, characterized in that: The step of determining the damage state of the steel wire of the object further comprises the following steps: detecting the degree of damage to the steel wire of the object; and detecting a damaged portion of the steel wire of the object to be inspected, In the step of detecting a damaged portion of the wire of the subject, a plurality of feature quantities including at least a feature quantity indicating kurtosis are used.

9. The wire diagnosis method according to claim 8, characterized in that: In the step of detecting a damaged portion of the steel wire of the subject, any combination of kurtosis and amplitude, kurtosis and half-value width, or kurtosis and area is used.

10. The wire diagnosis method according to claim 7, characterized in that: In the step of detecting the distance, the Mahalanobis distance is used as the distance.

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