JP2018054332A - Abnormality detection method and abnormality detection apparatus of filament, and jig used for abnormality detection apparatus of filament - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality detection method which can detect abnormality difficult to be distinguished such as small corrosion of a filament.SOLUTION: An abnormality detection method of a filament comprises a process to calculate amplitude integration values of sampling waveforms of an analyte and a reference respectively, a process to acquire plural amplitude integration rates by calculating amplitude integration rates each of which is a rate of the amplitude integration value of the analyte to the amplitude integration value of the reference in each prescribed integration range, and a process to judge that there is an abnormality when a determination value which is obtained from the plural amplitude integration rates is a prescribed threshold value or more.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an abnormality detection method and an abnormality detection device for a linear body, and a jig used in the abnormality detection device for a linear body.

  Conventionally, ultrasonic flaw detection has been performed in order to detect breakage of each strand of a cable composed of a plurality of strands.

  For example, in the detection method described in Patent Document 1, an ultrasonic pulse is sent from an end of a strand of a cable that is a subject to the inside of the strand, and the reflection that occurs when the ultrasonic pulse is reflected at a broken location. By receiving the signal at the end, the presence / absence of the broken wire and the position of the broken wire are detected.

JP-A-61-111460

  In the detection method of Patent Document 1 described above, ultrasonic waves are transmitted from the cable end, the received reflected signal is detected, and the disconnection of the cable is detected. However, with this detection method, it is difficult to detect small abnormalities that occur in the cable before the occurrence of disconnection, such as abnormalities such as thinning and cracking. This is because even if the amplitude of the received data acquired with respect to a healthy cable is seen, it changes finely in time. The cause of this amplitude change is considered to be caused by interference of various waves as shown in the following (i) to (iv).

Here, for example, a parallel line cable in which the button head is provided at the end of the linear body or a fixing tool such as a wedge is fixed to the end of the linear body with a tooth shape on the cable to be detected. PC steel strands are included. Therefore, the following four kinds of reflected waves (i) to (iv) obtained from waves propagated in the cable through a button head or a wedge-shaped portion provided at the end of the cable. Can be considered.
(I) Reflection from the crystal grain boundary of the material constituting the cable when it is transmitted from the cable end and propagates through the cable passing through the toothed portion of the button head or wedge provided at the cable end. wave.
(Ii) A reflected wave caused by the roughness of the cable surface when propagating through the cable passing through the tooth profile portion of the button head or the wedge.
(Iii) Among waves propagating in the cable passing through the tooth profile portion of the button head or the wedge, etc., waves having a slower propagation speed may cause a grain boundary of the material constituting the cable or a rough surface of the cable surface. Reflected wave due to the height.
(Iv) Of the waves propagating through the cable after being reflected in the tooth profile portion of the button head or wedge, the reflected wave is caused by the crystal grain boundary of the material constituting the cable or the roughness of the cable surface.

  When detecting abnormalities of linear objects, in order to detect the presence or absence of minute corrosion at a short distance, the presence or absence of a crack at a middle distance, the presence or absence of a break at a long distance, a minute signal that appears in the received signal Need to be processed and judged. However, since the amplitude of the received signal changes with time due to the reflected waves as described in (i) to (iv) above, by setting a certain threshold, It is difficult to determine the presence or absence of a crack at a medium distance and the presence or absence of a break at a long distance.

  Here, in order to detect abnormalities that are difficult to discern, such as the above-mentioned minute corrosion and long-distance disconnection, the sampling waveform created from the reflection signal of the subject's strand is used as a reference for the reflection of a healthy strand of reference. It is conceivable to detect the presence / absence of an abnormality based on the magnitude of the amplitude difference between the sampling waveforms compared to the sampling waveforms created from the signals.

  However, since the strands to be inspected have different end shapes and other conditions, the threshold value for determining the presence / absence of an abnormality when detecting the presence / absence of an abnormality by the amplitude difference between two sampling waveforms is set. Difficult to set uniquely. For this reason, it is difficult to detect the presence or absence of an abnormality that is difficult to determine, such as minute corrosion of the wire, and to specify the position where the abnormality has occurred.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an abnormality detection method capable of detecting an abnormality that is difficult to distinguish, such as minute corrosion of a linear body.

  In order to solve the above problems, the abnormality detection method for a linear body according to the present invention is an abnormality detection method for detecting an abnormality in a linear body of a subject, from an end of a reference linear body. A step of acquiring reference reception data by transmitting ultrasonic waves to the inside of the linear body, and preparing a reference sampling waveform created using the reference reception data; Transmitting an ultrasonic wave from the end of the linear body to the inside of the linear body to obtain received data for the subject, and using the received data for the subject, A step of creating a sampling waveform, a step of calculating a plurality of reference amplitude integral values by integrating the absolute value of the amplitude of the reference sampling waveform for each predetermined integration range, and the sampling waveform for the subject The absolute value of the amplitude of each predetermined integration range Integrating a plurality of amplitude integral values for the subject by integration, and an amplitude integral ratio, which is a ratio between the amplitude integral value for the subject and the amplitude integral value for reference, for each predetermined integration range Calculating and calculating a plurality of amplitude integration ratios, and determining whether there is an abnormality when a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value. To do.

  Transmit from the end of the linear body even when there are abnormalities such as microscopic corrosion inside the linear body that are difficult to distinguish, such as short-distance micro-corrosion, medium-range cracks, or long-distance breaks. When the reflected ultrasonic wave is reflected from the location where the abnormality has occurred, the reflected signal is dispersed and continues for a while. This shows a behavior different from the noise included in the reflected signal. Therefore, the present invention focuses on such behavior of the reflected signal and proposes a method of detecting an abnormality of the linear body using the determination value obtained from the amplitude integration ratio of the sampling waveform.

  In this method, the amplitude integration ratio is obtained based on the sampling waveform of the subject and the reference sampling waveform.

  That is, a sampling waveform is created using reception data acquired when ultrasonic waves are transmitted to the subject's linear body, and the absolute value of the amplitude of the sampling waveform is integrated for each predetermined integration range. A plurality of amplitude integration values for the specimen are calculated. The plurality of amplitude integration values for the subject are compared for each predetermined integration range with the plurality of reference amplitude integration values calculated in the same manner for the reference linear body, and a plurality of amplitude integration ratios are calculated. .

  When a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value, it is detected that there is an abnormality in the linear body of the subject. This is because the reflected signal is dispersed and persists for a while in a place where there is an abnormality inside the subject's linear body, so that abnormality determination is performed by paying attention to the phenomenon that the increase in the amplitude integration ratio of the sampling waveform continues. It is. As a result, it is possible to accurately detect the occurrence of an abnormality in the linear body even when the reflected signal from an abnormal portion that is difficult to discriminate such as minute corrosion or disconnection at a long distance is small. Experiments by the inventors have revealed that the increase in the amplitude integration ratio in such an abnormal part hardly changes even if the shape of the end part of the subject's linear body and other conditions differ individually. ing. However, an increase in the amplitude integration ratio has been confirmed by experiments where an abnormality has occurred. Therefore, it is possible to uniquely set a threshold value that determines whether there is an abnormality. Further, it is possible to specify a position corresponding to the vicinity of the integration range where the increase in the amplitude integration ratio occurs as the abnormality occurrence location of the linear body.

  The determination value is preferably the amplitude integration ratio of the plurality of amplitude integration ratios.

  According to such a feature, since the amplitude integration ratio itself of a plurality of amplitude integration ratios is used as the determination value, it is possible to quickly identify the abnormality occurrence place of the linear body without performing complicated data processing. Is possible.

  Integrating an absolute value of an angle-related value related to an inclination angle with respect to a time axis for each predetermined time in the reference sampling waveform to calculate a plurality of reference angle integrated values for each predetermined integration range; Integrating the absolute value of the angle-related value related to the tilt angle with respect to the time axis for each predetermined time in the sampling waveform for the object to calculate a plurality of angle integral values for the object by integrating for each predetermined integration range. Calculating an angular integral ratio that is a ratio of the angular integral value for the subject and the reference angular integral value for each of the predetermined integration ranges, and obtaining a plurality of the angular integral ratios, Calculating a plurality of ratio differences that are differences between the amplitude integration ratio and the plurality of angle integration ratios for each integration range, and the determination value is a value of the plurality of ratio differences. Preferably a serial percentage difference.

  According to such a feature, it is possible to accurately detect abnormality of a linear body by using a ratio difference that is a difference between an amplitude integration ratio and an angle integration ratio as a determination value obtained from the amplitude integration ratio of a sampling waveform. Is possible.

  In this method, based on the sampling waveform of the subject and the sampling waveform for reference, the angle integration ratio is obtained in addition to the amplitude integration ratio described above. That is, a plurality of angle integral values for the subject are calculated by integrating the absolute value of the angle-related value related to the tilt angle with respect to the time axis for every predetermined time in the sampling waveform for the subject for each predetermined integration range. The plurality of angle integration values for the subject are compared for each predetermined integration range with the plurality of reference angle integration values calculated in the same manner for the reference linear body to calculate a plurality of angle integration ratios. .

  Thereafter, a plurality of ratio differences, which are differences between the plurality of amplitude integration ratios and the plurality of angle integration ratios, are calculated for each integration range. Then, using the ratio difference among a plurality of ratio differences as a determination value, when the ratio difference is greater than or equal to a predetermined threshold value, it is detected that there is an abnormality in the subject's linear body. This is because the change in the amplitude of the sampling waveform is larger than the change in angle because the reflected signal is dispersed and persists for a while in the place where there is an abnormality inside the linear body of the subject. The abnormality determination is performed by paying attention to a phenomenon in which the deviation between the angle integration ratio and the angle integration ratio continues. In this case, the amplitude integration ratio is influenced by various factors, for example, factors such as the shape of the end of a linear body (for example, a button head) that transmits and receives ultrasonic waves and the contact state of the ultrasonic probe. Even if received, the phenomenon that the above divergence persists does not change. As a result, it is possible to detect the abnormality of the linear body more accurately even when the reflected signal from the abnormal part that is difficult to distinguish, such as minute corrosion or disconnection at a long distance, is small. The difference between the amplitude integral ratio and the angle integral ratio is more difficult to change than the increase in the amplitude integral ratio described above, even if the shape of the end of the subject's linear body and other conditions are individually different. It has become clear through experiments by the inventors. However, it has been experimentally confirmed that the amplitude integration rate and the angle integration rate are different in a place where an abnormality has occurred. Therefore, it is possible to uniquely set a threshold value that determines whether there is an abnormality. In addition, a position corresponding to the vicinity of the integration range where such a deviation between the amplitude integration ratio and the angle integration ratio occurs can be specified as the abnormality occurrence location of the linear body.

  The angle-related value is preferably an angle conversion value that is a ratio of the tilt angle to 90 degrees.

  According to this feature, it is possible to easily and accurately calculate the angle integral value by using the angle conversion value that is the ratio of the tilt angle with respect to 90 degrees as the angle-related value.

  The angle related value may be the tilt angle itself. By using the tilt angle itself as the angle-related value, it is possible to easily and accurately calculate the angle integral value.

  The angle related value may be sin θ where the tilt angle is θ. By using sin θ when the inclination angle is θ as an angle-related value, it is possible to easily and accurately calculate the angle integral value.

  The sampling frequency for creating the sampling waveform is preferably 2 to 10 times the ultrasonic frequency.

  Within this range, a sampling waveform with a small deviation from the received data can be obtained, and an increase in the number of data necessary to form the sampling waveform can be suppressed.

  The integration range is preferably in the range of 10 to 100 times the wavelength of the ultrasonic wave.

  Within this range, the influence of the amplitude change of the sampling waveform is not excessively detected and the abnormality is not excessively detected, and the abnormality is not easily affected by the amplitude change and the abnormality is not overlooked.

  It is preferable that the linear body has a button head having an enlarged shape in the radial direction of the linear body at an end portion thereof.

  In the case of a linear body having such a button head, even if only one pulse is emitted from the button head to the inside of the linear body, multiple reflections are made inside the button head, and the ultrasonic waves inside the linear body are also reflected. Since the dispersion of sound waves becomes significant, it is difficult to detect abnormalities inside the linear body. However, in the case of the abnormality detection method described above, by using the determination value obtained from the amplitude integral ratio, the influence of the disturbance of the reflected signal caused by the surface shape of the button head is reduced. It is possible to accurately detect abnormalities that are difficult to distinguish, such as minute corrosion inside and disconnection at a long distance. Similarly to the button head, when the fixing device such as a wedge has a surface shape such as a PC steel strand fixed with a tooth shape at the end of the linear body, the reflected signal is disturbed due to the tooth shape portion. Therefore, it is possible to accurately detect abnormalities that are difficult to distinguish, such as minute corrosion inside the linear body and disconnection at a long distance.

  The linear body of the subject is the strand in a wire cable composed of a plurality of strands, and the closest to the center of the wire cable among the plurality of strands as the reference linear body It is preferable that a strand is selected.

  When detecting an abnormality of each strand of a wire cable composed of multiple strands, select the strand closest to the center of the wire cable where the occurrence of the abnormality is the lowest as the reference linear body. Since it becomes possible to procure (prepare) the linear body for inspection at the site of the inspection work, it is not necessary to carry the reference linear body into the site or the like. In particular, it is advantageous in the case of inspection work at a high place such as inspection of wire cables for bridges.

  The abnormality detection apparatus for a linear body according to the present invention is an abnormality detection apparatus that detects an abnormality in a linear body of a subject, and has a portion that can contact an end of the linear body. An ultrasonic probe for transmitting ultrasonic waves toward the inside of the linear body and acquiring received data from the linear body, and a sampling waveform forming unit for forming a sampling waveform based on the received data A subject data storage unit that stores a sampling waveform related to the linear body of the subject formed by the sampling waveform forming unit, and a sampling waveform related to a reference linear body formed by the sampling waveform forming unit An absolute value of the amplitude of the sampling waveform stored in each of the reference data storage unit, the object data storage unit, and the reference data storage unit is stored in a predetermined integration range. An amplitude integration unit that integrates each time and calculates a plurality of amplitude integral values for the subject and the reference, and an amplitude integration ratio that is a ratio of the amplitude integral value for the subject and the amplitude integral value for the reference An amplitude integration comparator that calculates each of the predetermined integration ranges and obtains a plurality of the amplitude integration ratios, and an abnormality is present when a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value An abnormality determination unit for determining is provided.

  According to such a configuration, the sampling waveform forming unit creates a sampling waveform for the subject by using the reception data acquired when the ultrasound probe transmits the ultrasonic wave to the linear body of the subject. . The amplitude integrating unit integrates the absolute value of the amplitude of the sampling waveform for each predetermined integration range, and calculates a plurality of amplitude integrated values for the subject. The amplitude integration comparison unit compares the plurality of amplitude integration values for the subject with the plurality of reference amplitude integration values similarly calculated for the reference linear body for each predetermined integration range, Calculate the amplitude integration ratio. The abnormality determining unit detects that there is an abnormality in the linear body of the subject when a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value. This is because the reflected signal is dispersed and persists for a while in a place where there is an abnormality inside the subject's linear body, so that abnormality determination is performed by paying attention to the phenomenon that the increase in the amplitude integration ratio of the sampling waveform continues. It is. As a result, it is possible to accurately detect the occurrence of an abnormality in the linear body even when the reflected signal from an abnormal portion that is difficult to discriminate such as minute corrosion or disconnection at a long distance is small.

  A jig according to the present invention is a jig used in the above-described linear body abnormality detection apparatus, and includes a frame portion that can be attached to an end portion of a linear body assembly including a plurality of linear bodies, and the frame. A holding unit that holds the ultrasonic probe in a position corresponding to each end surface of the linear body and facing in a direction corresponding to the normal direction of the end surface of the linear body in association with the unit It is characterized by having.

  According to such a configuration, when detecting an abnormality of each linear body among the plurality of linear bodies of the linear body assembly, the ultrasonic probe is attached to the linear body using the above jig. Fixed to the end face. That is, the frame portion of the jig is attached to the end portion of the linear body assembly, and in association with the frame portion, the holding portion is positioned at a position corresponding to each end face of the linear body, And it hold | maintains so that it may face in the direction which corresponds to the normal line direction of the end surface of the said linear body. As a result, the ultrasonic probe can be brought into contact with the end surface of the linear body from a direction that matches the normal direction of the end surface of the linear body. It is possible to suppress the variation in the contact state with the end face, thereby reducing the variation in the received signal.

  In the configuration in which the linear assembly further includes a fixing unit that covers the outer circumferences of the plurality of linear bodies in a state where the ends of the plurality of linear bodies are bundled, the frame unit is provided on an end surface of the fixing unit. It is preferable to have an attachable configuration.

  According to such a configuration, it is possible to stably fix the ultrasonic probe to the end portion of the linear assembly via the jig by fixing the frame portion to the end surface of the fixing portion of the linear assembly. is there.

  The holding portion has a through-hole into which the ultrasonic probe can be fitted, and the through-hole is in a state in which the ultrasonic probe is fitted with the linear shape of the ultrasonic probe. It is preferable to have an inner diameter that is large enough to be held in a direction that matches the normal direction of the end face of the linear body with respect to the end face of the body.

  According to such a configuration, the ultrasonic probe is aligned with the normal direction of the end surface of the linear body with respect to the end surface of the linear body simply by fitting the ultrasonic probe into the through hole of the holding portion. It becomes possible to make it contact from the direction to do. As a result, the workability of the inspection work is improved.

  The frame portion has an opening portion having an opening area capable of exposing end faces of the plurality of linear bodies, and the holding portion includes the measurement part having the through hole and the measurement portion. A fixing part for fixing the part inside the opening, and the measurement part and the fixing part are fitted into the opening so that the through hole of the measurement part is formed. You may arrange | position in the position corresponding to the end surface of the said linear body.

  According to this configuration, it is possible to accurately set the through hole of the measurement part at the position of the end face of the linear body to be inspected among the plurality of linear bodies. Thus, by fitting the ultrasonic probe into the through hole, the ultrasonic probe is brought into contact with the end surface of the linear body from a direction that matches the normal direction of the end surface of the linear body. It becomes possible to make it.

  It is preferable that the holding unit has a configuration capable of holding a plurality of the ultrasonic probes.

  According to such a configuration, it is possible to simultaneously bring a plurality of the ultrasound probes into contact with a plurality of linear bodies that are the subject, thereby improving the workability of the inspection work.

  The holding unit may have a configuration capable of holding the ultrasonic probe so as to be arranged in a triangle.

  According to such a configuration, the ultrasonic probe can be arranged in a triangle by the holding unit, and as a result, the three ultrasonic probes are respectively connected to the end surfaces of the linear bodies. It becomes possible to make it contact | abut correctly from the direction which corresponds to the normal line direction of the end surface.

  It is preferable that the apparatus further includes a selection connection unit that selects any one of the plurality of ultrasonic probes and selectively connects to an external device.

  According to such a configuration, even when the holding unit holds a plurality of ultrasonic probes, the ultrasonic probe can be individually connected to an external device by the selective connection unit.

  As described above, according to the abnormality detection method and abnormality detection apparatus for a linear body according to the present invention, abnormalities that are difficult to distinguish, such as minute corrosion of a linear body, for example, short-distance corrosion, medium distance A case where there is a crack or a disconnection at a long distance can be detected.

  According to the jig of the present invention, it is possible to suppress variations in the contact state between the ultrasonic probe and the end face of the linear body, thereby reducing variations in received signals.

It is a block diagram which shows the basic composition of the abnormality detection apparatus of the linear body which concerns on 1st Embodiment of this invention. It is an expanded sectional view which shows the edge part of the strand of the probe and wire cable of FIG. It is a flowchart which shows the procedure of the abnormality detection method of the linear body which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows roughly a mode that the ultrasonic wave transmitted from the probe of FIG. 1 propagates the inside of the strand of a wire cable. It is a graph which shows the receiving waveform by the receiving data acquired from the healthy strand for a reference received by the probe of FIG. It is the figure which showed typically formation of the sampling waveform. It is a graph for demonstrating integrating the absolute value of the amplitude of the sampling waveform of FIG. 6 is a graph for explaining the integration of the absolute value of the amplitude for each predetermined integration interval T1 in the sampling waveform formed from the reception waveform of FIG. 9 is a graph showing reference amplitude integral values for each integration interval calculated by integrating the absolute value of the amplitude for each predetermined integration interval T1 in the sampling waveform of FIG. It is a graph explaining integrating the absolute value of an amplitude for every predetermined integration section T1 about the sampling waveform formed from the reception waveform of the strand of the subject. 11 is a graph showing the amplitude integrated value for the subject for each integration interval calculated by integrating the absolute value of the amplitude for each predetermined integration interval T1 from the sampling waveform of FIG. (A) is a graph which shows an example of the sampling waveform for a reference, (b) is a graph which shows the several amplitude integral value calculated | required from the sampling waveform for a reference of (a). (A) is a graph showing an example of a sampling waveform for a subject (example of 50-day corrosion), and (b) shows a plurality of amplitude integration values obtained from the sampling waveform for a subject of (a). It is a graph. 13 is a graph showing an amplitude integration ratio that is a ratio of a plurality of amplitude integration values for the subject in FIG. 13B to a plurality of reference amplitude integration values in FIG. (A) is a graph which shows the other example (example of 100-day corrosion) of the sampling waveform for test objects, (b) is the several amplitude integral value calculated | required from the sampling waveform for test objects of (a) It is a graph which shows. It is a graph which shows the amplitude integral ratio which is a ratio of the some amplitude integral value for the test object of FIG.15 (b) with respect to the several amplitude integral value for reference of FIG.12 (b). It is a block diagram which shows the basic composition of the abnormality detection apparatus of the linear body which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the procedure of the abnormality detection method of the linear body which concerns on 2nd Embodiment of this invention. It is a graph which shows inclination-angle (theta) with respect to the time axis for every predetermined time (DELTA) t of a sampling waveform. It is a graph of the angle conversion value for a reference calculated from the sampling waveform of FIG. FIG. 21 is a graph showing reference angular integration values for each integration interval calculated by integrating the absolute value of the reference angle conversion value of FIG. 20 for each predetermined integration interval T1. It is a graph of the angle conversion value for the object calculated from the sampling waveform of the object formed by sampling the reception data from the wire of the object. FIG. 23 is a graph showing the angle integrated value for the subject for each integration interval calculated by integrating the absolute value of the angle conversion value for the subject in FIG. 22 for each predetermined integration interval T1. Indicates the amplitude integration rate and angle integration rate for each integration interval. It is a graph which shows a mode that the said amplitude integral ratio and the angle integral ratio are largely deviating after 9. (A) is a graph which shows the change of the amplitude in a sampling waveform, and the change of an angle, respectively, (b) is a graph which shows the degree of a change of an amplitude integral value and an angle integral value. It is a graph which shows the standard of the abnormality determination of a strand from the relationship between the distance from a strand end part, and the difference of ratio comparison. It is a figure which shows a mode that a probe does not contact | win perpendicularly to the end surface of a strand, when making a probe contact | abut to the edge part of each strand of a cable. It is explanatory drawing which shows the state which contact | abuts a probe perpendicularly | vertically with respect to a strand using the jig | tool used for the abnormality detection apparatus of the linear body which concerns on 3rd Embodiment of this invention. FIG. 29 is an explanatory diagram showing a state in which a plurality of probes are collectively brought into contact with each element wire of the cable using the jig of FIG. 28. It is a figure which shows the outer frame which comprises the split-type jig | tool which concerns on 3rd Embodiment of this invention. It is a figure which shows the part for a measurement corresponding to the outer frame of FIG. 30 which comprises the split-type jig | tool which concerns on 3rd Embodiment of this invention. It is a figure which shows the fixing parts corresponding to the outer frame of FIG. 30 which comprises the split-type jig | tool which concerns on 3rd Embodiment of this invention. It is a figure which shows the end surface of the cable of FIG. It is a figure which shows the state which fixed the outer frame of FIG. 30 to the end surface of a cable. Using a split-type jig that combines the outer frame of FIG. 30, the measurement part of FIG. 31, and the fixing part of FIG. It is a figure which shows a mode that it is simultaneously contact | abutted to the end surface of a line. Using a split-type jig that combines the outer frame of FIG. 30, the measuring part of FIG. 31, and the fixing part of FIG. 32, the probes are arranged in a straight line, and a plurality of strands of the cable are arranged. It is a figure which shows a mode that it is made to contact | abut to an end surface simultaneously. It is a figure which shows the probe which can be simultaneously contact | abutted to the end surface of the some strand of a cable.

    Hereinafter, embodiments of the abnormality detection method and the abnormality detection apparatus of the present invention will be described in more detail with reference to the drawings.

(First embodiment)
An abnormality detection apparatus 1 according to the first embodiment shown in FIG. 1 is an apparatus that detects an abnormality in a linear body of a subject. This anomaly detection apparatus 1 is, for example, a cable composed of a plurality of strands 100 (for example, a bridge cable 200 for hanging and supporting a bridge girder as shown in FIG. 27) as a subject's linear body. Etc.), an abnormality (for example, a small corroded portion 102) of each strand 100 is detected with ultrasonic waves.

  The strand 100 constituting the cable for the bridge is made of, for example, a galvanized steel wire having a diameter of about 7 mm, and the button head 101 has a shape expanded in the radial direction of the strand 100 at the end of the strand 100. Have The button head 101 has, for example, a substantially hemispherical shape, and the surface thereof is curved. Note that the linear body that is the subject and the shape of its end are not particularly limited in the present invention. The linear body in the present invention may include not only a single wire but also a plurality of strands. For example, a parallel wire cable in which a plurality of strands are bundled in parallel, a wire rope formed by twisting a plurality of strands, a PC steel strand, or the like is also included in the linear body of the present invention.

  The abnormality detection device 1 includes a probe 2 (hereinafter referred to as a probe 2) and a measuring instrument 12 electrically connected to the probe 2 via a signal line. The measuring instrument 12 includes a received data storage unit 3, a sampling waveform forming unit 4, an object data storage unit 5, a reference data storage unit 6, an amplitude integration unit 7, an amplitude integration comparison unit 8, and an abnormality determination. Part 9.

  The probe 2 has a portion that can contact the button head 101 at the end of the strand 100, transmits an ultrasonic wave from the end toward the inside of the strand 100, and the strand 100 The received data from is acquired.

  For example, the probe 2 shown in FIG. 2 is attached to a cylindrical main body case 2a, a piezoelectric element 2b and a wedge delay member 2c housed in the main body case 2a, and an opening on the front side of the main body case 2a. Soft retarder 2d. The piezoelectric element 2b is capable of transmitting the ultrasonic wave and receiving the reflected wave returned from the strand 100 as the subject to acquire the received data. As the ultrasonic wave transmitted from the piezoelectric element 2b, for example, an ultrasonic wave having a frequency of about 2 to 5 MHz for flaw detection of a steel material is used, but an ultrasonic wave having a frequency range other than that may be used.

  The wedge retarder 2c is made of a resin such as acrylic and is fixed to the front surface of the piezoelectric element 2b by adhesion or the like. The soft retarder 2d is made of a material softer than the wedge retarder 2c, such as rubber, and is fixed to the front surface of the wedge retarder 2c by adhesion or the like. The soft delay material 2c has a contact surface 2e having a concave shape so as to correspond to the curved surface of the button head 101. Therefore, when the contact surface 2e of the soft delay material 2c made of a soft material is in close contact with the curved surface of the button head 101, the piezoelectric element 2b receives the reflected wave returned from the strand 100 via the wedge delay material 2c. Thus, it is possible to obtain received data with high stability and reproducibility.

  The reception data storage unit 3 stores the reception data acquired by the probe 2.

  The sampling waveform forming unit 4 forms a sampling waveform (for example, the sampling waveform W2 in FIG. 6) based on the reception data stored in the reception data storage unit 3.

  The subject data storage unit 5 stores a sampling waveform related to the strand 100 of the subject formed by the sampling waveform forming unit 4.

  The reference data storage unit 6 stores a sampling waveform related to the reference strand 100 formed by the sampling waveform forming unit 4. As the reference strand 100, for example, a healthy strand having the same shape as the subject strand 100 and having no abnormality is employed.

  The reference strand 100 is a strand that is highly likely not to be abnormal among a plurality of strands constituting the bridge cable, specifically, at the center of the wire cable among the plurality of strands. The closest strand may be selected. When detecting an abnormality of each wire of a wire cable composed of a plurality of wires, the wire closest to the center of the wire cable with the lowest occurrence of the abnormality is selected as the reference wire 100 as described above. This makes it possible to procure (prepare) the reference wire 100 separately from the wire of the subject wire cable at the site of the inspection work. For this reason, it is not necessary to carry a reference wire into the site. In particular, it is advantageous in the case of inspection work at a high place such as inspection of wire cables for bridges.

  The amplitude integration unit 7 integrates the absolute values of the amplitudes of the sampling waveforms stored in the subject data storage unit 5 and the reference data storage unit 6 for each predetermined integration range, and a plurality of samples for the subject and the reference. Calculate the amplitude integral value.

  The amplitude integration comparison unit 8 calculates an amplitude integration ratio that is a ratio of the amplitude integration value for the subject and the reference amplitude integration value for each predetermined integration range, and obtains the plurality of amplitude integration ratios.

  The abnormality determination unit 9 uses the amplitude integration ratio of the plurality of amplitude integration ratios as a determination value obtained from a plurality of amplitude integration ratios. When the amplitude integration ratio is greater than or equal to a predetermined threshold value, Judge that there is.

  The abnormality detection method for the subject's linear body (specifically, the strand 100 of the bridge cable) using the abnormality detection apparatus 1 configured as described above is executed according to the procedure shown in the flowchart of FIG. Is done.

  First, reference reception data created using the reference reception data is acquired by transmitting ultrasonic waves from the end of the reference strand 100 to the inside of the strand 100 and acquiring the reference reception data. Are prepared (step S1 in FIG. 3). Here, the reference strand 100 is a galvanized steel wire having a button head 101 with a diameter of about 7 mm and a length of 1 m, and is a healthy strand having no abnormality.

  In order to acquire the reference received data, specifically, as shown in FIG. 4, the probe 2 is brought into contact with the button head 101 of the reference strand 100 and the ultrasonic wave S is transmitted. 100 sent to the inside. The ultrasonic wave S is sent, for example, by one pulse at a frequency of 5 MHz (the velocity of the ultrasonic wave S transmitted through the strand is about 5700 m / s and the wavelength is about 1.1 mm). The probe 2 receives the reception data indicated by the reception waveform shown in FIG.

  The ultrasonic wave S sent to the inside of the strand 100 is subjected to multiple reflections inside the button head 101 as shown in FIG. Therefore, in the received waveform shown in FIG. 5, in the range D <b> 1 close to the probe 2, the amplitude A increases due to multiple reflection inside the button head 101. Also in the intermediate range D2 inside the strand 100, the amplitude A is slightly affected by the multiple reflections at the button head 101 and the overlapping of the reflections inside the strand 100. In the range D3, a change in amplitude corresponding to the reflected wave at the end surface of the strand 100 far from the probe 2 is seen. In this range D3, it can be seen that the reflected wave is sustained for a while due to dispersion. The duration of the reflected wave tends to become longer due to the influence of multiple reflection at the button head 101.

  Next, the sampling waveform forming unit 4 forms a sampling waveform from the received data in the inspection range D in the received waveform shown in FIG. Specifically, as shown in FIG. 6, the received waveform W1 is sampled at every time Δt, the amplitude value at every time Δt is extracted, and a sampling waveform W2 is formed by the group of the extracted amplitude values. .

  The time Δt is determined by the sampling frequency when creating the sampling waveform. That is, the time Δt is obtained as the reciprocal of the sampling frequency. The sampling frequency is preferably 2 to 10 times the frequency of the ultrasonic wave transmitted from the probe 2 (for example, the sampling frequency is preferably about 10 MHz with respect to the ultrasonic wave of 5 MHz). Within this range, a sampling waveform with a small deviation from the received data can be obtained, and an increase in the number of data necessary to form the sampling waveform can be suppressed.

  If the reference sampling waveform is prepared before the examination of the subject's linear body, it is not necessary to create the sampling waveform every time the subject's linear body is examined.

  Next, similarly to the reference strand 100, an ultrasonic wave is transmitted from the end of the subject strand 100 toward the inside of the strand 100 to obtain received data for the subject (FIG. 3 step S2). Then, a sampling waveform for the subject is created using the reception data for the subject (step S3).

  The strand 100 for the subject has a corroded portion 102 (for example, a portion whose diameter is reduced by about 0.4 to 0.6 mm) near the center as a small abnormality as shown in FIG. A line is used. About another point, it is the same specification as the strand 100 for reference (namely, the galvanized steel wire which has the button head 101 about 7 mm in diameter and 1 m in length).

  Next, the amplitude integrator 7 integrates the absolute value of the amplitude of the reference sampling waveform for each predetermined integration range T1, and calculates a plurality of reference amplitude integrated values (step S4). Schematically, the absolute value of the amplitude of the sampling waveform W2 shown in FIG. 6 (full-wave rectification that makes the negative component of the amplitude positive) is obtained for each predetermined integration range T1 as shown in FIG. It is obtained by integrating into.

  More specifically, as shown in FIG. 8, the sampling waveform formed from the received waveform obtained from the reference wire in FIG. 5 is divided into, for example, 15 pieces for each predetermined integration interval T1 (each integration interval). Are assigned integration interval numbers No. 1 to 15). Then, as shown in FIG. 9, the sampling waveform of FIG. 8 is integrated with the absolute value of the amplitude for each predetermined integration interval T1, so that the reference amplitude for each integration interval T1 is obtained as shown in FIG. Calculate the integral value.

  Here, the integration range T1 is preferably in the range of 10 to 100 times the wavelength of the ultrasonic wave transmitted from the probe 2 (for example, when the wavelength of the ultrasonic wave is about 1.1 mm, The integration range T1 is preferably about 60 mm, which is about 50 times the wavelength.) Within this range, the influence of the amplitude change of the sampling waveform is not excessively detected and the abnormality is not excessively detected, and the abnormality is not easily affected by the amplitude change and the abnormality is not overlooked. Therefore, it becomes easy to distinguish an abnormal signal from noise (that is, the S / N ratio increases).

  Similarly to the above, the amplitude integrator 7 also integrates the absolute value of the amplitude of the sampling waveform for the subject for each predetermined integration range T1, as shown in FIG. 10, and as shown in FIG. A plurality of amplitude integral values for the subject for each integration range T1 are calculated (step 4).

  Next, the amplitude integration comparison unit 8 calculates an amplitude integration ratio that is a ratio between the amplitude integration value for the subject and the reference amplitude integration value for each predetermined integration range, and a plurality of the amplitude integration ratios B1. (Step 5).

  Then, the abnormality determination unit 9 uses the amplitude integration ratio of the plurality of amplitude integration ratios as a determination value obtained from the plurality of amplitude integration ratios, and when the amplitude integration ratio is equal to or greater than a predetermined threshold value. Judge that there is an abnormality.

  For example, the amplitude integration value for reference corresponds to the reference sampling waveform shown in FIG. 12A (corresponding to the position of 100 to 1000 mm from the end of the sound wire cable for reference by the amplitude integration unit 7. ) To 15 integration ranges shown in FIG. 12B, respectively.

  Similarly, the amplitude integration value for the subject is obtained by the amplitude integration unit 7 for 50 days when the sampling waveform for the subject shown in FIG. 13A (for example, salt water is added in the vicinity of 500 mm from the end of the wire cable). The 15 integral ranges shown in FIG. 13B are obtained from the corroded one).

  Next, the amplitude integration comparison unit 8 calculates an amplitude integration ratio B1 which is a ratio of the amplitude integration value for the subject in FIG. 13B to the amplitude integration value for reference in FIG. 12B. Each of the 15 integration ranges shown in FIG.

  Thereafter, the abnormality determination unit 9 determines that there is an abnormality when the amplitude integration ratio B1 shown in FIG. 14 is, for example, 2 or more as a predetermined threshold value.

  Further, if an integration range where the amplitude integration ratio B1 is equal to or greater than a predetermined threshold is known, a position corresponding to the vicinity of the integration range can be specified as an abnormality occurrence location of the strand 100.

  In addition, when the amplitude integrated value of FIG. 15B is obtained from the sampling waveform of FIG. 15A for a wire cable corroded for 100 days as another subject, the amplitude integration ratio B1 obtained from the amplitude integrated value is also obtained. Is as shown in FIG. Also in this case, the abnormality determination unit 9 can determine that there is an abnormality when the amplitude integration ratio B1 shown in FIG. 16 is at a predetermined threshold value (2 or more).

  As shown in the flowchart of FIG. 3 above, in the abnormality detection method using the abnormality detection device 1 of the first embodiment, the amplitude integration ratio B1 is set to the integration range based on the sampling waveform of the subject and the reference sampling waveform. It calculates | requires for every T1. Thereafter, when the amplitude integration ratio B1 among the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value, it is detected that there is an abnormality in the strand 100 of the subject. In this case, in a place where there is an abnormality inside the strand 100 of the subject, the reflected signal is dispersed and persists for a while, so that the abnormality determination is performed paying attention to a phenomenon in which the increase in the amplitude integral ratio continues. As a result, it is possible to accurately detect the occurrence of an abnormality in the strand 100 even when the reflected signal from an abnormal portion that is difficult to distinguish, such as minute corrosion or disconnection at a long distance, is small.

  In the abnormality detection method of the first embodiment, the amplitude integration ratio itself of the plurality of amplitude integration ratios is used as the determination value obtained from the plurality of amplitude integration ratios. As a result, it is possible to quickly identify the abnormality occurrence location of the linear body without performing complicated data processing.

(Second Embodiment)
In the abnormality detection method of the first embodiment described above, the amplitude integration ratio itself of the plurality of amplitude integration ratios is used as the determination value obtained from the plurality of amplitude integration ratios, but the present invention is limited to this. It is not a thing. Other determination values may be used as long as they are determination values obtained from a plurality of amplitude integration ratios.

  In the abnormality detection method of the second embodiment, the abnormality of the linear body is accurately detected by using a ratio difference that is a difference between the amplitude integration ratio and the angle integration ratio as the determination value obtained from the amplitude integration ratio of the sampling waveform. It is possible to detect well.

  The abnormality detection device 1 used in the abnormality detection method of the second embodiment is configured as shown in FIG. The abnormality detection device 1 shown in FIG. 17 is composed of a probe 2 and a measuring instrument 12 in the same manner as the abnormality detection apparatus 1 of the first embodiment shown in FIG. A data storage unit 3, a sampling waveform forming unit 4, an object data storage unit 5, a reference data storage unit 6, an amplitude integration unit 7, an amplitude integration comparison unit 8, and an abnormality determination unit 9 are provided. Since these configurations have already been described in the first embodiment, a description thereof will be omitted.

  However, the abnormality detection device 1 shown in FIG. 17 is different from the abnormality detection device 1 of the first embodiment shown in FIG. 1 in that it further includes an angle integration unit 10 and an angle integration comparison unit 11.

  The angle integration unit 10 calculates the absolute value of the angle-related value related to the tilt angle with respect to the time axis for each predetermined time in the sampling waveforms stored in the subject data storage unit 5 and the reference data storage unit 6 respectively, in a predetermined integration range. A plurality of integrated angle values for the subject and the reference are calculated by integrating each time. As the angle-related value, for example, an angle conversion value that is a ratio of an inclination angle with respect to 90 degrees is used. The angle-related value may be the tilt angle itself or may be sin θ with respect to the tilt angle θ.

  The angle integration comparison unit 11 calculates an angle integration ratio, which is a ratio between the angle integration value for the subject and the reference angle integration value, for each predetermined integration range, and obtains a plurality of the angle integration ratios.

  In the abnormality detection method of the second embodiment, an angle integral ratio is obtained in addition to the above-described amplitude integral ratio based on the sampling waveform of the subject and the reference sampling waveform. That is, a plurality of angle integral values for the subject are calculated by integrating the absolute value of the angle-related value related to the tilt angle with respect to the time axis for every predetermined time in the sampling waveform for the subject for each predetermined integration range. The plurality of angle integration values for the subject are compared for each predetermined integration range with the plurality of reference angle integration values calculated in the same manner for the reference linear body to calculate a plurality of angle integration ratios. .

  Specifically, the abnormality detection method of the second embodiment is executed according to the procedure shown in the flowchart of FIG.

  In the abnormality detection method of the second embodiment, first, similar to the flowchart of FIG. 3 of the abnormality detection method of the first embodiment, the preparation of the sampling waveform of the reference cable (step S1) and the reception data of the subject cable are performed. Acquisition (step S2), creation of sampling waveform of subject cable (step S3), amplitude integration (step S4) of each sampling waveform of reference cable and subject cable, and calculation of amplitude integration ratio (step S5) . The specific description of these steps S1 to S5 has already been described in the first embodiment, and will be omitted.

Next, the angle integration unit 10 integrates the absolute value of the angle-related value related to the tilt angle with respect to the time axis for each predetermined time in the reference sampling waveform for each predetermined integration range, and performs reference angle integration. A value is calculated (step S11). Specifically, first, as shown in FIG. 19, the inclination angles θ _{1 to} θ ₁₀ ... Are obtained for each sampling time Δt of the sampling waveform W2. When the angle conversion value R that is the ratio of the tilt angle with respect to 90 degrees is adopted as the angle-related value, first, a graph of the time series change of the angle conversion value R shown in FIG. 20 is obtained. Then, the absolute value of the angle conversion value R is integrated for each predetermined integration range T1, and a plurality of reference angle integration values as shown in FIG. 21 are calculated.

  Similarly to the above, the angle integration unit 10 also applies to the sampling waveform for the subject, as shown in FIGS. 22 to 23, an angle related value (related to the inclination angle θ with respect to the time axis for each predetermined time Δt ( Specifically, the absolute value of the angle conversion value R) is integrated for each predetermined integration range T1 to calculate a plurality of angle integration values for the subject (step S11).

  Then, the angle integration comparison unit 11 calculates an angle integration ratio B2 that is a ratio between the angle integration value for the subject and the reference angle integration value for each predetermined integration range, and calculates a plurality of angle integration ratios B2. Obtained (step S12).

  Next, as shown in FIG. 24, the abnormality determination unit 9 has a plurality of ratios that are differences between the plurality of amplitude integration ratios B1 obtained in step S5 and the plurality of angle integration ratios B2 obtained in step S12. The difference G is calculated for each integration range T1.

  Then, the abnormality determination unit 9 uses the ratio difference G among the plurality of ratio differences G as a determination value, and determines that there is an abnormality when the ratio difference G is equal to or greater than a predetermined threshold value δ.

  As shown in the flowchart of FIG. 18, in the abnormality detection method using the abnormality detection apparatus 1 of the present embodiment, the amplitude integration ratio B1 and the angle integration ratio are based on the sampling waveform of the subject and the reference sampling waveform. B2 is obtained for each integration range T1. Thereafter, a plurality of ratio differences G, which are differences between the plurality of amplitude integration ratios and the plurality of angle integration ratios, are calculated for each integration range. Then, using the ratio difference among the plurality of ratio differences as a determination value, when the ratio difference is equal to or greater than the predetermined threshold δ, it is detected that the subject wire 100 is abnormal. This is because, in a place where there is an abnormality inside the strand 100 of the subject, the reflected signal is dispersed and continues for a while, so that the change in the amplitude of the sampling waveform becomes larger than the change in the angle, and the amplitude integration ratio described above The abnormality determination is performed by paying attention to a phenomenon in which the deviation between the angle integration ratio and the angle integration ratio continues. In this case, the amplitude integration ratio is affected by various factors, for example, factors such as the shape of the end of the strand 100 (for example, the button head 101) that transmits and receives ultrasonic waves and the contact state of the probe 2. Even if received, the phenomenon that the above divergence persists does not change. As a result, it is possible to more accurately detect the occurrence of an abnormality in the strand 100 even when the reflected signal from an abnormal portion that is difficult to discriminate such as minute corrosion or disconnection at a long distance is small.

  For example, when the amplitude A of the waveform I is doubled as in the waveform II as in the sampling waveforms I and II shown in FIG. 25A, the integral value of the amplitude A is also doubled in proportion thereto. become. However, even if the amplitude of the waveform I is doubled as in the waveform II, the upper limit of the inclination angle θ2 of the waveform II of the waveform I is 90 degrees, so that the inclination angle θ1 of the waveform I is twice as large. Not simple. For this reason, the integrated value of the angle θ2 does not become twice the integrated value θ1 of the angle θ1. Therefore, as shown in FIG. 25B, it is considered that the amplitude integration C1 of the waveform and the angular integration C2 of the waveform deviate as the amplitude increases.

  When the change of the ratio difference G, which is the difference between the amplitude integration ratio B1 and the angle integration ratio B2 shown in FIG. 1-No. In the range of 7, even if the shape of the end of the strand 100 of the subject and other conditions are different from each other, the increase in the amplitude integration ratio used as the determination value in the abnormality detection method of the first embodiment Is even more difficult to change. However, the integration interval No. where the abnormality occurs is shown. If the vicinity of 8-9 is seen, the said No. It has been confirmed that the amplitude integration ratio B1 and the angle integration ratio B2 deviate in the range of 9 and later. Therefore, the threshold value δ for determining the presence or absence of abnormality can be uniquely set as a reference for the degree of deviation between the amplitude integration ratio B1 and the angle integration ratio B2.

  Further, the position corresponding to the vicinity of the integration range (for example, integration interval No. 8 to 9) immediately before the integration range T1 in which such a deviation between the amplitude integration ratio B1 and the angle integration ratio B2 occurs is set on the strand 100. It is possible to identify the location of the abnormality.

  The ratio difference G that is the difference between the amplitude integration ratio B1 and the angle integration ratio B2 tends to decrease as the distance from the end of the wire 100 (specifically, the button head 101) increases. Therefore, it is preferable to create an abnormality diagnosis map that associates the distance L from the end portion shown in FIG. In this map, the area defined by the two parameters of the distance L and the ratio difference G is divided into three areas corresponding to “break”, “abnormal”, or “sound”. These three regions are obtained by using a sample wire having an artificial defect (disconnection, crack, thinning due to corrosion, etc.), the above two parameters (distance L and ratio difference G), and the state of the wire. Set by examining the relationship. Using such a map for diagnosis shown in FIG. 26, if the distance L from the end portion and the ratio difference G are known, the state of the strand is either “break”, “abnormal”, or “sound” It is possible to easily and accurately determine whether this is the case. Further, if such a map is stored in the abnormality determination unit 9 of the abnormality detection device 1 of FIG. 1, the abnormality detection device 1 can perform an automatic diagnosis of the state of the strand at the site of the inspection work. It becomes possible.

  In the abnormality detection method of the above embodiment, the angle conversion value that is the ratio of the tilt angle with respect to 90 degrees is used as the angle-related value, so that the angle integral value can be calculated easily and accurately. . Even if the tilt angle itself is used as the angle-related value, the angle integral value can be easily and accurately calculated. Further, even if sin θ when the inclination angle is θ is used as the angle-related value, the angle integral value can be easily and accurately calculated.

  The strand 100 that is the subject of the abnormality detection method of the first embodiment and the second embodiment has a button head 101 having an enlarged shape in the radial direction of the strand 100 at the end thereof. In the case of the strand 100 having such a button head, even if only one pulse is emitted from the button head to the inside of the strand 100, multiple reflections are made inside the button head, and the ultrasound inside the strand 100 is also reflected. Since the dispersion of sound waves becomes significant, it is difficult to detect abnormality inside the strand 100. However, in the above-described abnormality detection method, the determination value obtained from the amplitude integration ratio (for example, the amplitude integration ratio itself in the first embodiment, or the amplitude integration ratio and the angle integration ratio in the second embodiment) By using (difference), the influence of the disturbance of the reflection signal due to the surface shape of the button head is reduced, so that it is possible to accurately detect abnormalities that are difficult to distinguish, such as minute corrosion inside the strand 100 or disconnection at a long distance. Is possible. Similarly to the button head, when the fixing device such as a wedge has a surface shape such as a PC steel strand fixed with a tooth shape at the end of the linear body, the reflected signal is disturbed due to the tooth shape portion. Therefore, it is possible to accurately detect abnormalities that are difficult to distinguish, such as minute corrosion inside the linear body and disconnection at a long distance.

  Thus, the above-described abnormality detection method is also useful for a method of forming a tooth profile on the surface of the striatum by a method of fixing (holding) the striatum using a wedge or the like.

(Third embodiment)
If the abnormality detection methods of the first embodiment and the second embodiment described above are used, it is possible to individually detect abnormality in the plurality of strands 201 (linear bodies) constituting the bridge cable 200 shown in FIG. Is possible.

  However, if the probe 2 is not in normal surface contact with the end surface 201a of the strand 201 in the vertical direction, the transmission state of ultrasonic waves from the probe 2 to the strand 201, and the probe The reception state of the reflected wave by 2 becomes unstable, and there is a possibility that the received signal varies.

  Therefore, in the present embodiment, the jig 21 shown in FIG. 28 is used in order to bring the probe 2 into normal surface contact with the end surface 201a of each strand 201 of the bridge cable 200.

  Here, the bridge cable 200 shown in FIGS. 27 to 28 is a linear body assembly including a plurality of strands 201 (linear bodies). For example, the plurality of strands 201 and the plurality of strands 201 A fixing unit 202 that covers the outer periphery of the plurality of strands 100 in a state where the ends of the strands 100 are bundled.

  As shown in FIG. 28, the jig 21 includes a frame portion 22 and a holding portion 23 that holds the wire 201.

  The frame portion 22 has a configuration that can be attached to the fixing portion 202 that constitutes the end portion of the bridge cable 200. Specifically, the frame 22 has a contact surface 22a that can contact the end surface 202a of the fixing unit 202, and is fixed to the end surface 202a by a fixing means such as a screw.

  The holding unit 23 is associated with the frame unit 22 and is positioned in a position corresponding to each end surface 201a of the element wire 201 and the direction matching the normal direction of the end surface 201a of the element wire 201. It has the structure hold | maintained so that it may face. Specifically, the holding part 23 is formed integrally with the frame part 22. The holding part 23 has a plurality of through holes 23a into which the probe 2 can be fitted. The plurality of through-holes 23a are arranged at positions corresponding to the end surfaces 201a of the plurality of strands 201, respectively. Each through-hole 23a holds the probe 2 in a direction that matches the normal direction of the end surface 201a of the strand 201 with respect to the end surface 201a of the strand 201 in a state in which the probe 2 is fitted. It has an inner diameter that is as large as possible. In addition, the structure which has the groove | channel which the probe 2 can fit may be sufficient as the holding | maintenance part 23 instead of the through-hole 23a.

  When detecting an abnormality of each of the strands 201 of the plurality of strands 201 of the bridge cable 201, the probe 2 is fixed to the end surface 201a of the strand 201 using the jig 21 described above. That is, when the frame portion 23 of the jig 21 is attached to the end surface 202 a of the fixing portion 202 of the bridge cable 200, the through hole 23 a of the holding portion 23 formed integrally with the frame portion 22 is positioned on the end surface 201 a of the strand 201. Placed in. In this state, if the probe 2 is inserted into the through hole 23a that exposes the subject wire 201, the probe 2 is positioned at a position corresponding to each end surface 201a of the strand 201 and the relevant strand. It can be held so as to face in a direction that coincides with the normal direction of the end surface 201a of 201. Thereby, the probe 2 is brought into contact with the end surface 201a of the element wire 201 from a direction that coincides with the normal direction of the end surface 201a of the element wire 201 (that is, in contact with the end surface 201a from the vertical direction). And the variation in the contact state between the probe 2 and the end surface 201a of the strand 201 can be suppressed, thereby reducing the variation in the received signal.

  Further, the jig 21 has a configuration in which the frame portion 22 can be attached to the end surface 202 a of the fixing portion 202. Therefore, by fixing the frame portion 22 to the end surface 202a of the fixing portion 202, the probe 2 can be stably fixed to the end portion of the bridge cable 200 via the jig 21.

  Furthermore, in said jig | tool 21, the holding | maintenance part 23 has the some through-hole 23a which the probe 2 can fit. Each through-hole 23a holds the probe 2 in a direction that matches the normal direction of the end surface 201a of the strand 201 with respect to the end surface 201a of the strand 201 in a state in which the probe 2 is fitted. It has an inner diameter that is as large as possible. Therefore, only by fitting the probe 2 into the through-hole 23a of the holding portion, the probe 2 can be viewed from an orientation that matches the normal direction of the end surface 201a of the strand 201 with respect to the end surface 201a of the strand 201. It becomes possible to contact. As a result, the workability of the inspection work is improved.

  As shown in FIG. 29, if a plurality of probes 2 are inserted into the through holes 23 a of the jig 21 in advance, the jig 21 is fixed to the end surface 202 a of the fixing unit 202. The probe 2 can be brought into contact with the end surfaces 201a of the plurality of strands 201 at once from the normal direction. Therefore, the workability of the inspection work is further improved.

  In addition, as shown in FIG. 29, the jig 21 selects one of the plurality of probes 2 and selectively switches to the measuring instrument 12 as an external device as a selection switch 24 as a selection switch. May be provided. In that case, even when the holding unit 23 holds a plurality of probes 2, the probe 2 can be individually connected to the measuring instrument 12 by the changeover switch 24.

  Furthermore, as shown in FIG. 29, the jig 21 preferably has a recess 22b on the surface facing the end surface 202a of the fixing unit 202, and the contact medium 25 is preferably filled in the recess 22b in advance. In this case, it is possible to interpose the contact medium 25 between each probe 2 and the end surface 201a of the element wire 201 opposed thereto, and it is possible to reduce variations in the reception state of ultrasonic waves. . Moreover, the operation | work which apply | coats a contact medium to each probe 2 becomes unnecessary.

  In the jig 21 shown in FIGS. 28 to 29, the frame portion 22 and the holding portion 23 are integrally formed. However, the present invention is not limited to this, and the frame portion 22 and the holding portion 23 are held. The unit 23 may be configured separately.

  For example, by combining the frame portion 22 having the opening 22c shown in FIG. 30 and the holding portion 23 including the plurality of measurement parts 28 and the plurality of fixing parts 29 shown in FIGS. You may make it comprise the jig | tool 21 shown by 35-36.

  The frame portion 22 shown in FIG. 30 has an opening portion 22c having an opening area capable of exposing end surfaces 201a (see FIG. 33) of the plurality of strands 201. The size and shape of the opening 22c may be appropriately set according to the number and arrangement of the strands 201.

  The measurement part 28 shown in FIG. 31 is composed of one or a plurality of hexagonal blocks, and has the above-described through-holes 23a into which the probe 2 is fitted for each block. The plurality of hexagonal blocks are connected in a straight line or in a triangular shape.

  The fixing part 29 shown in FIG. 32 is composed of one or a plurality of hexagonal blocks, like the measurement part 28 described above, but does not have the through hole 23a.

  30 has a shape that can be fitted to the measurement part 28 and the fixing part 29 shown in FIGS. 31 to 32 described above.

  The measuring part 28 and the fixing part 29 may be triangular or quadrangular blocks in addition to hexagonal blocks.

  When assembling the jig 21 shown in FIGS. 35 to 36, first, with respect to the end surface 202a of the fixing portion 202 where the end surfaces 201a of the plurality of strands 201 in the bridge cable 200 shown in FIG. 33 are exposed. The frame portion 22 is fixed. For example, as shown in FIGS. 30 and 34, the frame portion 22 is fixed to the end surface 202 a of the fixing portion 202 by a plurality of bolts 26. In this state, the end surfaces 201a of all the strands 201 are exposed through the openings 22c of the frame portion 22.

  Next, as shown in FIGS. 35 to 36, with the probe 2 fitted in the through hole 23a of the measurement part 28, the through hole 23a of the measurement part is in the end surface 201a of the strand 201 of the subject. The measurement part 28 and the fixing part 29 are fitted into the opening 22c of the frame part 22 so as to be arranged at the matching position. Therefore, it is possible to accurately set the through hole 23a of the measurement part at the position of the end surface 201a of the subject strand 201 among the plurality of strands 201. Accordingly, the probe 2 fitted in the through hole 23a can be brought into contact with the end surface 201a of the strand 201 from a direction that matches the normal direction of the end surface 201a of the strand 201. .

  In the jig 21 of FIG. 35, the three probes 2 are arranged in a triangle, and in the jig 21 of FIG. 36, the three probes 2 are arranged in a straight line. In this way, three (plural) probes 2 can be simultaneously brought into contact with the end surface 201a of the strand 201 of the subject. Thereby, the workability of the inspection work is improved. In particular, like the jig 21 in FIG. 35, the measurement parts 28 constituting the holding unit 23 hold the three probes 2 so as to be arranged in a triangle, thereby allowing the three probes 2 to be respectively arranged. It is possible to accurately contact the end surface 201a of the strand 201 from a direction that matches the normal direction of the end surface 201a of the strand 201.

  Instead of the configuration in which the plurality of probes 2 are held by the measurement part 28 as in the jig 21 shown in FIGS. 35 to 36, the end faces of the plurality of strands 201 as shown in FIG. Large probes 30 and 31 that can be brought into contact with 201a in a lump may be used. In this case, the inspection time can be shortened.

DESCRIPTION OF SYMBOLS 1 Abnormality detection apparatus 2 Ultrasonic probe 4 Sampling waveform formation part 5 Subject data storage part 6 Reference data storage part 7 Amplitude integration part 8 Amplitude integration comparison part 9 Abnormality judgment part 10 Angle integration part 11 Angular integration comparison part 21 Jig 22 Frame portion 22c Opening portion 23 Holding portion 23a Through hole 24 Changeover switch (selective connection portion)
28 Measurement Parts 29 Fixing Parts 100 Wire (Linear)
101 Button Head 102 Corroded Part 200 Bridge Cable 201 Wire 202 Fixing Part

Claims (18)

An abnormality detection method for detecting an abnormality in a linear body of a subject,
Sampling for reference created using the reference reception data by transmitting ultrasonic waves from the end of the reference linear body to the inside of the linear body to acquire reference reception data. Preparing the waveform;
Transmitting ultrasonic waves from the end of the linear body of the subject to the inside of the linear body to obtain received data for the subject;
Creating a sampling waveform for the subject using the received data for the subject;
Integrating the absolute value of the amplitude of the sampling waveform for reference for each predetermined integration range to calculate a plurality of amplitude integrated values for reference;
Integrating the absolute value of the amplitude of the sampling waveform for the subject for each predetermined integration range to calculate a plurality of amplitude integral values for the subject;
Calculating an amplitude integral ratio that is a ratio of the amplitude integral value for the subject and the reference amplitude integral value for each of the predetermined integral ranges, and obtaining a plurality of the amplitude integral ratios;
An abnormality detection method for a linear body, comprising: a step of determining the presence of an abnormality when a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value. The determination value is the amplitude integration ratio of the plurality of amplitude integration ratios.
The method for detecting abnormality of a linear body according to claim 1. Integrating an absolute value of an angle-related value related to an inclination angle with respect to a time axis for each predetermined time in the reference sampling waveform to calculate a plurality of reference angle integrated values for each predetermined integration range;
Integrating the absolute value of the angle-related value related to the tilt angle with respect to the time axis for each predetermined time in the sampling waveform for the object to calculate a plurality of angle integral values for the object by integrating for each predetermined integration range. When,
Calculating an angular integration ratio that is a ratio of the angular integration value for the subject and the reference angular integration value for each of the predetermined integration ranges, and obtaining a plurality of the angular integration ratios;
Calculating a plurality of ratio differences that are differences between a plurality of amplitude integration ratios and a plurality of angle integration ratios for each integration range;
Further including
The determination value is the ratio difference among the plurality of ratio differences.
The method for detecting abnormality of a linear body according to claim 1. The angle-related value is an angle conversion value that is a ratio of the tilt angle to 90 degrees.
The abnormality detection method for a linear body according to claim 3. The angle related value is the tilt angle itself.
The abnormality detection method for a linear body according to claim 3.   The linear body abnormality detection method according to claim 3, wherein the angle-related value is sin θ where the inclination angle is θ. The sampling frequency when creating the sampling waveform is 2 to 10 times the frequency of the ultrasonic wave,
The abnormality detection method for a linear body according to any one of claims 1 to 6. The integration range is a range of 10 to 100 times the wavelength of the ultrasonic wave,
The method for detecting abnormality of a linear body according to any one of claims 1 to 7. The linear body has a button head having a shape enlarged in the radial direction of the linear body at an end thereof.
The method for detecting abnormality of a linear body according to any one of claims 1 to 8. The linear body of the subject is the wire in a wire cable composed of a plurality of wires,
As the reference linear body, a strand closest to the center of the wire cable is selected from the plurality of strands.
The abnormality detection method of the linear body of any one of Claims 1-9. An abnormality detection device for detecting an abnormality in a linear body of a subject,
Ultrasound that has a portion that can contact the end of the linear body, transmits ultrasonic waves from the end toward the inside of the linear body, and acquires received data from the linear body With a probe,
A sampling waveform forming unit that forms a sampling waveform based on the received data;
A subject data storage unit that stores a sampling waveform related to the linear body of the subject formed by the sampling waveform forming unit;
A reference data storage unit for storing a sampling waveform related to the reference linear body formed by the sampling waveform forming unit;
A plurality of amplitude integration values for the subject and the reference are calculated by integrating the absolute values of the amplitudes of the sampling waveforms stored in the subject data storage unit and the reference data storage unit for each predetermined integration range. An amplitude integrator to
An amplitude integration comparator that calculates an amplitude integration ratio that is a ratio of the amplitude integration value for the subject and the reference amplitude integration value for each of the predetermined integration ranges, and obtains a plurality of the amplitude integration ratios;
An abnormality detection apparatus for a linear body, comprising: an abnormality determination unit configured to determine whether there is an abnormality when a determination value obtained from the plurality of amplitude integration ratios is equal to or greater than a predetermined threshold value. A jig used in the abnormality detection device for a linear body according to claim 11,
A frame portion attachable to an end portion of a linear body assembly including a plurality of linear bodies;
In association with the frame portion, the ultrasonic probe is held at a position corresponding to each end face of the linear body and in a direction corresponding to the normal direction of the end face of the linear body. Having a holding part,
jig. In the configuration in which the linear assembly further includes a fixing unit that covers the outer circumferences of the plurality of linear bodies in a state where the ends of the plurality of linear bodies are bundled.
The frame portion has a configuration that can be attached to an end surface of the fixing portion.
The jig according to claim 12. The holding portion has a through-hole into which the ultrasonic probe can be fitted,
The through-hole holds the ultrasonic probe in an orientation that matches the normal direction of the end surface of the linear body with respect to the end surface of the linear body in a state where the ultrasonic probe is fitted. Having an inner diameter of a size that can be
The jig according to claim 12 or 13. The frame has an opening having an opening area capable of exposing end faces of the plurality of linear bodies,
The holding part is
A measuring part having the through hole;
It has a fixing part for fixing the measurement part inside the opening,
When the measurement part and the fixing part are fitted into the opening, the through hole of the measurement part is disposed at a position that matches the end surface of the linear body.
The jig according to claim 14. The holding unit has a configuration capable of holding a plurality of the ultrasound probes.
The jig according to any one of claims 12 to 15. The holding unit has a configuration capable of holding the ultrasonic probe so as to be arranged in a triangle.
The jig according to claim 15. A selection connection unit that selects any one of the plurality of ultrasonic probes and selectively connects to an external device;
The jig according to claim 16 or 17.