JP7757243B2 - Wire rope flaw detector and wire rope diagnostic method - Google Patents

Description

The present invention relates to flaw detection for measuring the condition of magnetic metal materials, and in particular to a wire rope flaw detection device and wire rope diagnostic method suitable for detecting breaks in wire rope strands.

Patent Document 1 describes a magnetic flaw detector that detects damage to a wire rope by exciting a wire rope moving in the longitudinal direction to magnetically saturate it, and then detecting leakage magnetic flux with magnetic sensors arranged around the wire rope. Two rows of magnetic sensors are arranged along the length of the wire rope, with the same number of magnetic sensors in each row arranged at equal intervals in the circumferential direction. Furthermore, the corresponding magnetic sensors in each row are arranged so that at the moment one magnetic sensor faces the crest of the wire rope, the other magnetic sensor faces the valley of the wire rope (see abstract).

Japanese Patent Application Laid-Open No. 2005-156419

For example, the strand pitch length of a wire rope used in an elevator changes as it stretches due to the weight of the car during operation. The strand pitch length also changes depending on the operating time. In other words, the strand pitch length changes over time. With wire ropes whose strand pitch length changes over time, it is not possible to position sensors precisely at the peaks and valleys of the strands, and the phase difference between the strand noise signals generated by the peaks and valleys of the strands is not necessarily 90 degrees. Therefore, adding the strand noise signal does not result in a nearly constant value, making it difficult to reduce strand noise.

The object of the present invention is to provide a wire rope flaw detector and diagnostic method that can reduce wire rope strand noise signals regardless of the placement of magnetic sensors along the length (longitudinal) of the wire rope.

In order to achieve the above object, the wire rope flaw detector of the present invention comprises:
A wire rope flaw detector for detecting damage to a wire rope, comprising: a magnetizer that forms a magnetic path in a predetermined section of the wire rope; and a plurality of magnetic sensors that can detect magnetic signals derived from leakage magnetic flux generated from wires of the wire rope.
a signal analysis unit including a signal collector that collects magnetic signals output from the magnetic sensors and a signal processor that performs addition processing of the magnetic signals output from the signal collector;
The signal analysis unit
performing phase adjustment to adjust the positions of peaks and valleys of waveforms originating from the strands included in the plurality of magnetic signals detected by the plurality of magnetic sensors;
acquiring summed data of the plurality of phase-adjusted magnetic signals, and comparing the summed data with a first threshold value;
If the summed data is greater than the first threshold value, it is determined that there is damage to the wire rope;
If it is determined that there is damage to the wire rope, the individual magnetic signals of the plurality of magnetic sensors are compared with a second threshold value, and a first magnetic sensor that detects an individual magnetic signal that is greater than the second threshold value is identified .

In order to achieve the above object, the wire rope diagnosis method of the present invention comprises the steps of:
A wire rope diagnosis method using a wire rope flaw detector that detects damage to the wire rope, the method comprising: a magnetizer that forms a magnetic path in a predetermined section of the wire rope; and a plurality of magnetic sensors that can detect magnetic signals derived from leakage magnetic flux generated from wires of the wire rope,
performing a phase adjustment to adjust the positions of peaks and valleys of waveforms originating from the strands included in the plurality of magnetic signals detected by the plurality of magnetic sensors;
acquiring sum data of the plurality of phase-adjusted magnetic signals;
comparing the summed data with a first threshold;
determining that the wire rope is damaged when the summed data is greater than the first threshold value ;
When it is determined that there is damage to the wire rope, comparing the individual magnetic signals of the plurality of magnetic sensors with a second threshold value, and identifying a first magnetic sensor that detected an individual magnetic signal that is greater than the second threshold value;
Includes.

The present invention provides a wire rope flaw detector and diagnostic method that can reduce wire rope strand noise signals regardless of the placement of magnetic sensors along the length (longitudinal) of the wire rope.

1 is a schematic diagram (cross-sectional view) showing the configuration of a sensor section of a wire rope flaw detector according to one embodiment of the present invention. FIG. 2 is a functional block diagram showing the configuration of a signal processing unit and the like of a wire rope flaw detector according to one embodiment of the present invention, which is configured by connecting the sensor unit of FIG. 1. [0023]FIG. FIG. 4 is a schematic diagram of phase adjustment of a strand noise signal according to an embodiment of the present invention. 10 is a flowchart of an addition determination process according to an embodiment of the present invention. 4 is a flowchart of a wire breakage detection process according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of a detection signal resulting from a break in a wire according to an embodiment of the present invention. FIG. 10 is a diagram showing an example of a display of a determination result according to an embodiment of the present invention. FIG. 10 is a diagram showing the positional relationship between a sensor unit and a wire rope according to a comparative example of the present invention.

A wire rope is made by twisting multiple thin wires together to form a strand, which is then twisted around a core rope to form a single bundle. Wire ropes made from twisted magnetic metal wires are used as hoisting ropes for elevator car cages. Elevator wire ropes, which are used as running ropes, undergo deterioration over time, including bending fatigue, wear, and corrosion, and therefore require regular inspections and testing. Visual inspection is effective for detecting deterioration that shows obvious changes in appearance, such as rust and corrosion, but it is difficult to detect abnormalities that occur inside the wire rope, as there is variation in inspection accuracy among inspectors.

For this reason, an effective wire rope safety monitoring technique is to use magnetic leakage flux testing, which detects the deterioration state of wire ropes based on the leakage magnetic flux generated by the wire rope. Magnetic leakage flux testing involves exciting a wire rope and detecting the resulting leakage magnetic flux using a magnetic sensor. Measuring devices based on magnetic leakage flux testing (hereinafter referred to as magnetic leakage flux testing devices) are equipped with a magnetizer to magnetize the wire rope, with magnets attached to both ends of the magnetizer in a direction that reverses the polarity. When the wire rope adheres to the magnetizer, the magnetic field emitted from the magnet causes magnetic flux to flow back between the wire rope and the magnetizer, forming a magnetic path.

When a wire rope with a magnetic path formed experiences damage, such as a broken wire, the flow of magnetic flux is interrupted, causing magnetic flux to leak onto the wire rope's surface. A broken wire in the wire rope can be detected by detecting this leakage magnetic flux with a magnetic sensor. When this happens, the magnetic sensor not only detects signals from the broken wire, but also periodic signals from the wire rope's strands. This is because, unlike pipes with a uniform surface, wire ropes have an uneven surface due to their twisted strand structure, resulting in constant changes in magnetic flux. The peaks (ridges) of the strands are close to the magnetic sensor, resulting in a large signal, while the valleys (valleys) of the strands are farther from the sensor, resulting in a weaker signal, resulting in a periodic signal in accordance with the strand structure. This is called strand noise or strand noise signal, and is one of the causes of a low S/N ratio when detecting broken wires in a wire rope.

One example of a leakage flux inspection device that reduces such strand noise is the leakage flux inspection device shown in Figure 8. Figure 8 is a diagram showing the positional relationship between sensor units 4a and 4b and the wire rope 1 in a comparative example to the present invention. Figure 8 is a diagram of the magnetic flaw inspection device for wire ropes described in Patent Document 1, which is a type of leakage flux inspection device. The magnetic flaw inspection device disclosed in Patent Document 1 excites a wire rope that moves in the longitudinal direction and detects leakage magnetic flux generated from the wire rope using multiple magnetic sensors arranged circumferentially around the wire rope.

In the magnetic flaw detection device shown in Figure 8, when the wire rope 1 is moved longitudinally, the magnetic sensors 4a and 4b detect signals from the strand's valleys 1b and crests 1a, respectively, and these signals are 90 degrees out of phase. Therefore, by adding the signals from each magnetic sensor derived from the strand's valleys 1b and crests 1a, it is possible to reduce strand noise.

Patent Document 1 also discloses technology for calculating the effective cross-sectional area of a wire rope from the total added value of multiple magnetic sensors. Because the amount of leakage magnetic flux calculated from the added value is inversely proportional to the effective cross-sectional area, an increase in the amount of leakage magnetic flux indicates damage to the wire rope. Therefore, it is possible to determine the external or internal damage state of the wire rope from changes in the amount of leakage magnetic flux.

In the magnetic flaw detection device described in Patent Document 1, magnetic sensors are positioned in advance to align with the peaks and valleys of the wire rope strands. Addition is performed by adjusting the wire rope strand pitch and the number of sensors. However, the wire rope used in elevators stretches due to the weight of the car during actual operation, causing the strand pitch length to change. As a result, it is not possible to precisely position magnetic sensors at the peaks and valleys of the strands, and the phase difference between strand noise signals is not necessarily 90 degrees. Therefore, even when strand noise signals are added, the result is not an approximately constant value, making it difficult to reduce noise.

In addition, in Patent Document 1, the total amount of leakage magnetic flux per effective cross-sectional area of the wire rope is calculated from the sum of the magnetic sensor values, but when the wire rope is in actual operation, the variation in the total amount of leakage magnetic flux increases due to changes in the strand pitch length. As a result, it is difficult to accurately determine whether or not an internal wire has broken, as the rate of change is particularly small.

Furthermore, in Patent Document 1, the readings from multiple magnetic sensors are added together, and information from each individual magnetic sensor cannot be obtained, making it impossible to determine the number of broken wires.

The magnetic leakage flux flaw detector of this embodiment, described below, can reduce wire rope strand noise regardless of the placement of the magnetic sensor, and can detect the frequency and type of wire breakage. In this embodiment, the magnetic leakage flux flaw detector will be referred to as a wire rope flaw detector.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram (cross-sectional view) showing the configuration of a sensor unit of a wire rope flaw detector according to one embodiment of the present invention.

The wire rope 2 shown in Figure 1 has eight strands 23, and the entire wire rope, including these eight strands 23, is twisted together. A wire rope 2 with this composition is merely one example of the type of wire rope that can be inspected by the wire rope flaw detector 1 of this embodiment; wire ropes with a different number of strands can also be similarly diagnosed by the wire rope flaw detector 1 of this embodiment.

The wire rope 2 and strands 23 are further composed of numerous wires 24, and the wire rope flaw detector 1 is required to reliably detect any breaks in these wires 24. Furthermore, wire breaks vary depending on the location; if they occur on the outer periphery of the strand 23, they are called mountain breaks 25 in the wire, and if they occur midway between adjacent strands, they are called valley breaks 26 in the wire. In other words, a valley break 26 is a break in a wire midway between the outermost and innermost parts of the strand 23 in the circumferential direction of the strand 23.

The magnetizer 30 forms a magnetic path in a predetermined section along the longitudinal direction of the wire rope 2. The magnetic sensor 3 is installed around the outer periphery of the cross section of the protective cover 22 of the wire rope 2. Multiple magnetic sensors 3 are arranged at equal intervals along the outer periphery of the wire rope 2 and, together with the protective cover 22, form an annular sensor unit 20. The wire rope 2 is inspected by inserting it into the ring of the annular sensor unit 20. However, since it is extremely difficult to insert the wire rope 2 into an elevator that is in operation, in actual inspection, the annular or cylindrical sensor unit 20 is split in half circumferentially, the wire rope 2 is clamped inside the open loop, and the loop is then closed back together before inspection.

The types of magnetic sensors 3 shown in FIG. 1 are typically detection coils and Hall elements, but other types such as TMR (Tunnel Magneto Resistive) sensors, AMR (Anisotropic Magneto Resistive) sensors, or GMR (Giant Magneto Resistive effect) sensors can also be used. The arrangement of the magnetic sensors 3 that make up the sensor unit 20 will vary depending on the type of magnetic sensor 3, with different optimal configurations being adopted.

This arrangement is intended to efficiently detect breaks in the wire 24 using a minimum number of magnetic sensors 3, and preferably involves arranging multiple sensors at a predetermined interval (pitch) facing the outer periphery of the wire rope 2. The magnetic sensors 3 that make up the sensor unit 20 are arranged in a single row around the outer periphery of the wire rope 2 at equal intervals, forming an annular sensor group. Two or more rows of annular sensor groups made up of multiple magnetic sensors 3 may be arranged, with multiple annular sensor groups offset in the axial direction (longitudinal direction of the wire rope). In this case, multiple annular sensor groups may be adjacent to each other on the same axis. The more magnetic sensors 3 that make up the sensor unit 20, the denser and more precise they are to cover all breaks in the wire 24, enabling higher detection accuracy. However, the sensor unit 20 is designed to be efficient by including the minimum number of magnetic sensors 3 necessary.

FIG. 2 is a functional block diagram showing the configuration of a signal processing unit and the like of a wire rope flaw detector 1 according to an embodiment of the present invention, which is configured by connecting the sensor unit 20 of FIG.
2 , the wire rope flaw detector 1 is configured with 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. The data input unit 9 and the data display unit 8 have a general-purpose computer (hereinafter referred to as "PC 18") connected to a power supply 10 and a control circuit 11, which is operated by a user to control the wire rope flaw detector 1. The control circuit 11 controls the magnetic sensor circuit 5 and the signal analysis unit 7.

Figure 2 shows only two representative paths (channels, hereafter also referred to as "ch") corresponding to two magnetic sensors 3. However, the actual number of magnetic sensors 3 constituting the sensor unit 20 is basically the same as the number of strands 23 (eight in this embodiment), or an integer multiple (ch). This is to detect peaks and valleys (strand noise) originating from the strands 23 and cancel the strand noise using a processing procedure described below. Specifically, if there are eight strands 23, the magnetic sensors 3 will be provided with 8, 16, or 24 channels; Figure 1 illustrates the case of 16 channels. The magnetic signal detected by the magnetic sensors 3 is amplified and noise is removed by the magnetic sensor circuit 5, and then output to the signal analysis unit 7.

The magnetic sensor circuit 5 has a magnetic signal amplifier (magnetic signal amplifier section) 12 and a filter circuit (filter circuit section) 13. The magnetic signal amplifier 12 amplifies the output signal from the magnetic sensor 3. The filter circuit 13 performs standard analog filtering on the output signal amplified by the magnetic signal amplifier 12, outputting an analog signal. The analog filtering removes noise components, including commercial frequency noise, and passes only signals in the desired frequency range.

In this way, the magnetic sensor circuit 5 performs analog processing on the magnetic detection signal output from the magnetic sensor 3 and outputs an analog magnetic signal to the signal analysis unit 7. 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 one-chip microcomputer, a single-board computer, or the like.

The signal processor 18 stores the digital magnetic signal output from the A/D converter 16 in the signal collector 17 by having the CPU (Central Processing Unit) read and execute a program stored in memory or storage. The signal processor 18 also has signal addition and digital filtering functions, and processes the signal after A/D conversion. It also stores threshold values that serve as judgment criteria pre-defined for each type of wire rope.

Processing by the signal analysis unit 7 can be achieved by program processing in the signal processor 18, and the data display unit 8 and data input unit 9 can also be related devices of the signal processor 18, such as a keyboard or LCD display.

Next, we will provide an overview of the analysis process used by the signal analysis unit 7 of the wire rope flaw detector 1 to determine whether a wire rope has been broken, and then we will explain the processing procedure in detail with reference to the drawings.

Leakage magnetic flux from the wire rope 2 is detected by the magnetic sensor 3 and, as mentioned above, converted into a digital signal by the A/D converter 16 of the signal analysis unit 7. If damage occurs to the wire rope 2, the leakage magnetic flux signal resulting from a broken wire is converted into a digital signal. In addition, strand noise generated from the strands 23 of the wire rope 2 and electromagnetic noise mixed in from outside are also converted in duplicate. Therefore, the signal processor 18 can use a digital filter to reduce the main noise, but because strand noise has a frequency very close to the signal frequency of a broken wire, it is difficult to remove using a digital filter alone.

To reduce strand noise, the signals are phase-adjusted and added. Figure 3 is a schematic diagram of phase adjustment of a strand noise signal according to one embodiment of the present invention.

The upper and lower signals in Figure 3(A) are outputs from different magnetic sensors, and are signals before the phase of the strand waveform has been adjusted. If these signals were added as is, the peaks and valleys of the signals would not cancel each other out, resulting in increased strand noise. Therefore, by detecting the peaks of the waveform and adjusting the phase from the reference signal as shown in Figure 3(B), the peaks and valleys of the signal can be canceled out, and the signal after addition will have a waveform with reduced strand noise, as shown in Figure 3(C). In this embodiment, the signal in the upper row is used as the reference signal, and the phase of the signal in the lower row is adjusted.

Furthermore, by adding the signals from the magnetic sensors 3 in the circumferential direction of the rope in the signal analysis unit 7, it is possible to capture changes in the leakage magnetic flux at the cross section of the wire rope. In this embodiment, the process for adding the leakage magnetic flux described above among the determination processes performed by the signal analysis unit 7 is called the "addition determination process," and the process flow is shown in Figure 4, which will be described later.

Figure 4 is a flowchart of the addition determination process according to one embodiment of the present invention. Note that Figure 4 assumes that the magnetic sensor 3 has 16 channels.

As shown in Figure 4, first, measurement of magnetic signals by the magnetic sensors 3 begins under control of the control circuit 11 (step S11). The magnetic sensors 3 are attached to the wire rope, and as the wire rope moves longitudinally, magnetic signals can be acquired as time-series data of leakage magnetic flux. The magnetic signals output from the magnetic sensors 3 of each channel detected in step S11 undergo analog processing in the magnetic sensor circuit 5, are converted to digital form by the A/D converter 16 of the signal analysis unit 7, and then are stored in the signal collector 17.

Next, the signal processor 18 adjusts the phase of the strand noise signal for the digital magnetic signal of each channel stored in the signal collector 17 (step S12). As a result of adjusting the phase of the magnetic signal in step S12, the positions of the peaks and valleys of the strand noise signal waveform are adjusted, and a time series total value (added data) is obtained by an addition process in step S13.

Next, the signal processor 18 compares the entire time series sum of the magnetic signal calculated in step S13 with a previously stored reference value (threshold, first threshold) and determines whether or not an abnormality exists by comparing the values (step S14). In step S14, if the time series sum is equal to or lower than the threshold, the wire rope is determined to be normal (step S15). If the time series sum exceeds the threshold (NO in step S14), the signal processor 18 diagnoses that an abnormality has occurred in the measured length of the wire rope, displays the analysis result on the data display unit 8 (step S16), and proceeds to step S17 for a detailed determination of the abnormality.

As described above, the wire rope flaw detector 1 of this embodiment has the following features:
A wire rope flaw detector (1) for detecting damage to the wire rope (2) includes a magnetizer (30) that forms a magnetic path in a predetermined section of the wire rope (2) and a plurality of magnetic sensors (3) that can detect magnetic signals derived from leakage magnetic flux generated from the wires of the wire rope (2),
a signal analysis unit (7) including a signal collector (17) that collects magnetic signals output from the magnetic sensor (3) and a signal processor (18) that performs addition processing of the magnetic signals output from the signal collector (17);
The signal analysis unit 7 performs phase adjustment of multiple magnetic signals detected by multiple magnetic sensors 3, obtains additive data of the phase-adjusted multiple magnetic signals, and detects damage to the wire rope 2 based on the additive data.

Note that adjusting the phase of multiple magnetic signals adjusts the positions of the peaks and valleys of the waveforms originating from the strands contained in the multiple magnetic signals.

The signal analysis unit 7 then compares the added data with a first threshold value, and if the added data is greater than the first threshold value, determines that there is damage (broken wires) in the wire rope 2.

Further, the diagnostic method for the wire rope 2 of this embodiment is as follows:
A wire rope diagnosis method using a wire rope flaw detector that includes a magnetizer that forms a magnetic path in a predetermined section of the wire rope and a plurality of magnetic sensors that can detect magnetic signals derived from leakage magnetic flux generated from the wires of the wire rope, and that detects damage to the wire rope, comprising:
Step S12: performing phase adjustment of a plurality of magnetic signals detected by a plurality of magnetic sensors 3;
Step S13: acquiring sum data of the plurality of phase-adjusted magnetic signals;
Step S14 detects damage to the wire rope 2 based on the added data;
Includes.

The processing flow shown in Figure 4 is a processing flow for determining the presence and frequency of abnormalities (wire breaks) over the entire length of the wire rope 2 from the threshold value (first threshold value) stored in the signal processor 18, and the processing flow in Figure 5, described below, is a processing flow for determining the type of wire break.

Figure 5 is a flowchart of the wire breakage detection process according to one embodiment of the present invention. In the example processing procedure in Figure 5, a further detailed analysis is performed on a wire rope that has been detected as abnormal by the addition detection process. This further detailed analysis is called "wire breakage detection."

To determine whether a wire has been broken, the individual signals (wire determination data) for each channel stored in the signal collector 17 are acquired (step S21). Next, the signal processor 18 compares the individual signals for each channel with a pre-stored threshold value (second threshold value) (step S22), and determines that no abnormalities exist for channels whose values are below the threshold value (step S23).

The signal from the magnetic sensor 3 of a channel that exceeds the threshold is determined to be abnormal (wire break) (step S24), and the signals from adjacent channels are compared (step S25). This is because the spread of leakage magnetic flux varies depending on the type of wire break, and an internal break, a valley break (reference numeral 26 in Figure 1), causes the magnetic field distribution to spread due to the increased distance from the magnetic sensor 3, and is detected by the magnetic sensors 3 of multiple channels. Therefore, a threshold (third threshold) is used for judgment on adjacent channels, and if a channel with a value above the threshold is detected, the wire is determined to have a valley break (step S26). On the other hand, if the signal from the magnetic sensor 3 of an adjacent channel is smaller than the third threshold, the magnetic flux leakage to the multiple magnetic sensors 3 is small and the distribution is steep, so the wire is determined to have a mountain break (reference numeral 25 in Figure 1) (step S27).

In determining the first, second, and third thresholds described above, it is possible to select whether or not to include the values of each threshold.

As described above, in this embodiment, when it is determined that the wire rope 2 is damaged, the signal analysis unit 7 compares the individual magnetic signals of the multiple magnetic sensors 3 with the second threshold value, and identifies the magnetic sensor 3 (first magnetic sensor) that detected an individual magnetic signal that is larger than the second threshold value.

Furthermore, the individual magnetic signal of the second magnetic sensor 3 adjacent to the first magnetic sensor 3 is compared with a third threshold value, and if the magnetic signal of the second magnetic sensor 3 is larger than the third threshold value, it is determined that a valley break 26 has occurred in the wire of the wire rope 2, and if the magnetic signal of the second magnetic sensor 3 is larger than the third threshold value, it is determined that a crest break has occurred in the wire of the wire rope 2.

In other words, if the magnetic signals from multiple adjacent magnetic sensors 3 are greater than a predetermined value (the second threshold or the third threshold), it is determined that a valley break has occurred in a wire of the wire rope 2.

In this case, if the magnetic signal from one of the multiple magnetic sensors 3 (first magnetic sensor) is greater than the second threshold, it is determined that a wire break has occurred in the wire rope 2.

If the magnetic signal from the magnetic sensor (second magnetic sensor) adjacent to one magnetic sensor (first magnetic sensor) 3 is greater than the third threshold value, it is determined that a valley break has occurred in the wire of the wire rope 2.

Figure 6 shows an example of a detection signal resulting from a wire breakage in one embodiment of the present invention. Figure 6(A) shows the summed waveform of 16 channels of magnetic sensors 3, and a signal range 70 exceeding the threshold is detected along part of the entire length of the rope. Figure 6(B) shows a channel in which an abnormality was detected in step S24 of Figure 5, allowing for detailed observation of the wire breakage. In Figure 6, the vertical axis represents the amplitude of the signal detected by the magnetic sensors 3, and the horizontal axis represents the movement time of the sensor unit 20 relative to the wire rope 2. The movement time on the horizontal axis corresponds to the position in the longitudinal direction of the wire rope 2. Note that Figure 6(B) shows an example in which four wire breakages (four locations) have been detected.

The results of this determination are displayed on the data display unit 8. The data display unit 8 is, for example, an LCD display connected via an output interface, and displays the results of the processing performed by the signal analysis unit 7 (analysis result display screen).

Figure 7 shows an example of the display of the judgment results according to one embodiment of the present invention. Figure 7 shows a specific example of the analysis result display screen by the data display unit 8. The analysis result display screen displays, for example, the presence or absence of abnormalities in the summation judgment, the type of wire break (valley break or mountain break), the number of broken wires, the model number, the analysis date and time, etc., along with the wire rope data (summation data and wire judgment data).

As described above, the wire rope flaw detector 1 according to this embodiment can reduce wire rope strand noise and detect leakage magnetic flux generated from a broken wire in the wire rope 2, regardless of the placement of the magnetic sensor 3, and can also perform simple abnormality detection and detailed wire break detection through signal addition processing.

The present invention may be used as a wire rope flaw detector and wire rope diagnostic method for inspecting hoisting cables in elevator safety monitoring.

1...wire rope flaw detector, 2...wire rope, 3...magnetic sensor, 5...magnetic sensor circuit, 7...signal analysis unit, 8...data display unit, 9...data input unit, 17...signal collector, 18...signal processor, 20...sensor unit, 23...strand, 24...wire, 25...break (mountain break) in wire 24 of wire rope 2, 26...break (valley break) in wire 24 of wire rope 2.

Claims (6)

A wire rope flaw detector for detecting damage to a wire rope, comprising: a magnetizer that forms a magnetic path in a predetermined section of the wire rope; and a plurality of magnetic sensors that can detect magnetic signals derived from leakage magnetic flux generated from wires of the wire rope.
a signal analysis unit including a signal collector that collects magnetic signals output from the magnetic sensors and a signal processor that performs addition processing of the magnetic signals output from the signal collectors;
The signal analysis unit
performing phase adjustment to adjust the positions of peaks and valleys of waveforms originating from the strands included in the plurality of magnetic signals detected by the plurality of magnetic sensors;
acquiring summed data of the plurality of phase-adjusted magnetic signals, and comparing the summed data with a first threshold value;
If the summed data is greater than the first threshold value, it is determined that there is damage to the wire rope;
A wire rope flaw detection device characterized by comparing the individual magnetic signals of the multiple magnetic sensors with a second threshold value when it is determined that there is damage to the wire rope, and identifying the first magnetic sensor that detected an individual magnetic signal that is larger than the second threshold value . In claim 1 ,
comparing an individual magnetic signal of a second magnetic sensor adjacent to the first magnetic sensor with a third threshold;
When the magnetic signal of the second magnetic sensor is greater than the third threshold value, it is determined that a valley break has occurred in a wire of the wire rope;
A wire rope flaw detector characterized in that it determines that a wire break has occurred in the wire rope when the magnetic signal of the second magnetic sensor is smaller than the third threshold value. In claim 1 ,
A wire rope flaw detector characterized by determining that a wire break has occurred in the wire rope when the magnetic signal of one of the plurality of magnetic sensors is greater than a second threshold value. In claim 3 ,
A wire rope flaw detector characterized by determining that a valley break has occurred in a wire of the wire rope when the magnetic signal of a magnetic sensor adjacent to the one magnetic sensor is larger than a third threshold value. In claim 1 ,
A wire rope flaw detector that determines that a valley break has occurred in a wire of the wire rope when the magnetic signals of multiple adjacent magnetic sensors are larger than a predetermined value. A wire rope diagnosis method using a wire rope flaw detector that detects damage to the wire rope, the method comprising: a magnetizer that forms a magnetic path in a predetermined section of the wire rope; and a plurality of magnetic sensors that can detect magnetic signals derived from leakage magnetic flux generated from wires of the wire rope,
performing a phase adjustment to adjust the positions of peaks and valleys of waveforms originating from the strands included in the plurality of magnetic signals detected by the plurality of magnetic sensors;
acquiring sum data of the plurality of phase-adjusted magnetic signals;
comparing the summed data with a first threshold;
determining that the wire rope is damaged when the summed data is greater than the first threshold value ;
When it is determined that there is damage to the wire rope, comparing the individual magnetic signals of the plurality of magnetic sensors with a second threshold value, and identifying a first magnetic sensor that detected an individual magnetic signal that is greater than the second threshold value;
A wire rope diagnostic method comprising: