JP2004184181A - Non-destructive inspection method using superconductive quantum interference element and non-destructive inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method for a steel core cable by a superconductive quantum interference element, which determines a position where a flaw is present of the steel core cable and a flaw state, and to provide an inspection device therefor. <P>SOLUTION: In a residual magnetism free state, the superconductive quantum interference element detects (1) the non-uniformity of the continuous position forward arranged magnetic flux value of a minute magnetic flux value, which is detected from the aggregate region of a minute magnetic charge magnetic dipole when the magnetic dipole of the steel core cable being a material having a three-dimensional structure carries a minute magnetic charge to form the aggrigate of the minute magnetic charge magnetic dipole, and (2) the non-uniformity, which is generated at a position where a flaw is present by generating a leak magnetic flux from the steel core cable by applying a uniform magnetic field to the steel core cable, to determine the position where the flaw is present of the steel core cable and the flaw state regardless of a ternary composite material and a complicated structure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention uses a superconducting quantum interference device (hereinafter referred to as a SQUID sensor) to detect a small magnetic flux to determine an internal defect of a steel core cable using a superconducting quantum interference device (hereinafter referred to as a SQUID sensor). And an internal inspection device for steel core cables.
[0002]
[Prior art]
As a conventional technique of “internal inspection of a magnetic material” for detecting an internal defect of a magnetic material by detecting with a SQUID sensor, Industrial Materials June 1998 (Vol. 46 No. 6) “Magnetic Properties and Material Evaluation (Part 4) ) "(Non-Patent Document 1, hereinafter referred to as Conventional Technique 1) and T.I. IEEE Japan, Vol. 115, No. 10, 1995 (1955), pages 968 to 973 (Non-Patent Document 2, hereinafter referred to as Conventional Technique 2).
[Difference between the present invention and the prior art]
As will be described later, the present invention is characterized in that the magnetic dipoles of the steel core having no remanence are charged with a minute magnetic charge and the steel core forms an aggregate of the magnetic dipoles with a minute magnetic charge. The magnetic field that applies a uniform magnetic field to the inner surface at the internal defect inspection position of the magnetic material, which is a feature of the second invention. Forming a magnetic field with a forming coil. " As described in the prior art 1 (Non-patent document 1) and the prior art 2 (Non-patent document 2), the prior art is based on the principle that “the operation principle of the SQUID sensor is a sensor that detects minute magnetic flux, a) a detection coil made of a superconducting wire and (b) an input coil made of a superconducting wire that transmits a magnetic flux to a SQUID sensor loop, and measure a voltage change when an external magnetic flux changes. That is. Hereinafter, (1) a comparison between the prior art 1 and the first invention, (2) a comparison between the prior art 1 and the second invention, (3) a comparison between the prior art 2 and the first invention, and (4) The prior art will be described in the order of comparison between the prior art 2 and the second invention.
(1) [Comparison between prior art 1 and first invention]
The operation principle of the SQUID sensor described in the prior art 1 is a sensor that detects a minute magnetic flux, and (a) “a detection coil made of a superconducting wire” and (b) “a superconducting wire that transmits a magnetic flux to a SQUID sensor loop. An operation principle for measuring a voltage change when an external magnetic flux changes is described. According to the detection principle of the prior art 1, the magnetic flux at both ends and the center of the reinforcing bar (magnetic body) changes, and the changed magnetic flux is detected by a detection coil.
[0003]
FIG. 2 is a principle diagram of a detection coil of the SQUID sensor described in Prior Art 1. In the figure, a SQUID sensor is used in which Josephson junctions J1 and J2 exhibiting quantum mechanical phenomena are incorporated in a ring R made of a superconducting wire, and a detection coil for measurement is combined with a superconducting ring. Josephson coupling is due to a quantum mechanical tunnel effect in which a thin insulating layer is sandwiched between superconductors and a current flows between two superconductors even when the voltage is zero. When the external magnetic flux Φa passes through a space surrounded by the ring R, a voltage V is generated at both ends of the ring R. Therefore, the SQUID sensor operates as an element that converts a minute magnetic flux into a voltage.
[0004]
In the prior art 1, (a) a change in the position of the magnetic material, (b) a change in the magnetic characteristics of the magnetic material, and (c) a change in the magnetic flux due to an eddy current of the non-magnetic material, a change in the eddy current, etc. are detected as magnetic flux changes. An inspection example is described. In the inspection example, there is described a technique of detecting a change in magnetic flux when a conventional SQUID sensor is moved in the diameter direction of a reinforcing bar to detect the position of a different-diameter reinforcing bar in concrete.
[0005]
On the other hand, in the inspection example described in the prior art 1, an example of detecting a change in magnetic characteristics of a magnetic body is described. FIG. 10 of prior art 1 shows that, after a fatigue test of stainless steel SUS304, which is a magnetic material, the residual magnetic charge changes due to an increase in the degree of fatigue to cause a change in magnetic flux and the output of the SQUID sensor increases. It is described that a "change" is detected.
[0006]
FIG. 11 of the prior art 1 describes that after performing the sensitizing heat treatment of SUS304, the “magnetic property change due to the heat treatment” in which the residual magnetic charge and the coercive force increase as the heat treatment time increases. Further, FIG. 12 of Prior Art 1 describes that after performing a fatigue test of carbon steel (magnetic material), "fatigue of a magnetic material" in which hysteresis increases due to increased fatigue is detected.
[0007]
They detect internal defects, deterioration, etc. of the magnetic material as changes in magnetic characteristics, but all use residual magnetic charges. Therefore, the inspection example described in the related art 1 is a feature of the first invention because the residual magnetic charge (coercive force) is used even when a defect inside the magnetic body is detected. It does not use the technique of "a magnetic dipole of a steel core having no residual magnetism bears a minute magnetic charge, and the steel core measures the magnetic flux value of the magnetic dipole of a minute magnetic charge."
[0008]
However, in the inspection example of the prior art 1, in the description of detecting the position of the rebar having different diameters in the concrete, "the magnetic dipole of the steel core bears a minute magnetic charge" which is a feature of the first invention is described. There is no description that the magnetic flux value is measured from the aggregate region of the magnetically charged magnetic dipoles in a state where the steel core forms the aggregate of the magnetically charged magnetic dipoles.
[0009]
In the inspection example described in the prior art 1, it is described that a change in magnetic flux due to an eddy current of a non-magnetic material, a change in an eddy current, and the like are detected as a change in the magnetic flux. In this non-magnetic material, the features of the first invention cannot be used because the magnetic dipole of the steel core does not exist.
[0010]
In the prior art 1, a block diagram of a non-destructive inspection device (or a block diagram of the non-destructive inspection device of the first invention) that implements the non-destructive inspection method of the first invention using the SQUID sensor of FIG. 1 described later is shown. "In a state where the magnetic dipoles of the steel core of the steel core cable having no residual magnetism bear a minute magnetic charge and the steel core forms an aggregate of the magnetic dipoles with a minute magnetic charge, the SQUID sensor detects the minuteness of the steel core cable. Since the inhomogeneity of the minute magnetic flux is detected from the aggregate regions Ma, Mb, Mc,... Of the magnetically charged magnetic dipoles, the aggregate regions Ma, Mb, Mc,. Cannot be detected from. "
(2) [Comparison between prior art 1 and second invention]
Further, in the inspection example of the prior art 1, in the description of detecting the position of the rebar having different diameters in concrete, the description of "the uniform magnetic field on the inner surface at the inspection position for the internal defect of the magnetic body", which is a feature of the second invention, is given. And a magnetic field forming coil that demagnetizes the remanence of the magnetic material and applies a uniform magnetic field to the inner surface of the magnetic material at the internal defect inspection position.
(3) [Comparison of prior art 2 with first invention]
In FIGS. 1, 3 and 5 of the prior art 2, the change in magnetic flux when the SQUID sensor was moved in the diameter direction of the reinforcing bar similar to that of the prior art 1 was measured, and the position of the rebar in the concrete was measured. A technique for detecting is described.
[0011]
FIG. 3 is an explanatory diagram when a reinforcing bar is detected by the SQUID sensor described in FIG. FIG. 4 is a concrete embedded different diameter reinforcing bar diagram showing the shape of the different diameter reinforcing bars embedded in the concrete which is the test body described in FIG. FIG. 5 is a schematic diagram of detecting the position of a buried reinforcing bar for detecting the position of the different-diameter reinforcing bar of the test body described in FIG.
[0012]
FIG. 6 is a diagram illustrating the distance in the outer peripheral direction from the center axis of the reinforcing bar and the detected voltage when the position of the different-diameter reinforcing bar of the test piece described in FIG. It is a reinforcing bar position detection voltage measurement diagram. The reason why the detected voltages are different even if the distance in the outer circumferential direction of the reinforcing bar is the same in the figure is that the distance “lift-off” between the SQUID sensor element and the reinforcing bar shown in FIG. 5 is different.
[0013]
Next, in the technology of detecting the position of the rebar of different diameter in concrete according to the prior art 2, nothing is described about the “input coil made of a superconducting wire that transmits a magnetic flux to the SQUID sensor loop”. On the other hand, "In this experiment, a rebar having a remanent magnetization capable of producing a magnetic flux of about 150 to 450 [mu] T at a distance of 108 mm was used as it is in the market. It is necessary to study whether this measurement method is applied to a locally magnetized rebar or a rebar with smaller remanent magnetization. "
[0014]
The above-mentioned prior art 2 has a problem that "it is necessary to study whether or not this measurement method is applied to a reinforcing bar having a smaller residual magnetization". In the measurement method of the prior art 2 in which this problem remains, as described above, the leakage magnetic flux due to the residual magnetic charge is used as an external magnetic flux for detection by the detection coil. The characteristic is that the magnetic dipole of the steel core with no residual magnetism takes on a minute magnetic charge, and the core measures the magnetic flux value of the magnetic dipole with a minute magnetic charge, which occurs at the position where the internal defect of the steel core cable exists It is not described that the minute magnetic flux value is arranged in the order of continuous positions of the steel core cable to determine the position where the internal defect exists and the defect state from the non-uniformity of the magnetic flux value. "
[0015]
Further, in the technology for detecting the position of a different-diameter reinforcing bar (rebar buried in a test body) in concrete according to Prior Art 2, a feature of the first invention is that “a magnetic dipole of a steel core having no residual magnetism is used. In the state where the steel core forms an aggregate of the magnetically charged dipoles with the magnetically charged particles, the detection is performed from the aggregated region of the magnetically charged magnetic dipoles. " Absent.
[0016]
In the prior art 2, as described above, a block diagram of a nondestructive inspection device that implements the nondestructive inspection method of the first invention using the SQUID sensor of FIG. 1 (or a block diagram of the nondestructive inspection device of the first invention) ), The state in which the magnetic dipoles of the steel core of the steel core cable having no residual magnetism bears a small magnetic charge and the steel core forms an aggregate of the magnetic dipole magnetic dipoles. Since the inhomogeneity of the minute magnetic flux is detected from the aggregated regions Ma, Mb, Mc,... Of the magnetically charged dipoles of the cable, if residual magnetism exists, the aggregated regions Ma, Mb, Mc, ... ".
(4) [Comparison between prior art 2 and second invention]
As described above, in the prior art 2, "In this experiment, the rebar which is commercially available is used as it is, and a residual magnetic charge capable of producing a magnetic flux of about 150 to 450 µT at a distance of 108 mm. In the future, it is necessary to study whether this measurement method is applied to locally magnetized rebars and rebars with smaller residual magnetization. "
[0017]
Therefore, the measuring method for detecting the position of the rebar having different diameters (concrete buried in the test piece) in concrete according to the prior art 2 uses the leakage magnetic flux due to the residual magnetization as an external magnetic flux for detecting by the detection coil. Therefore, the magnetic field forming coil for applying a uniform magnetic field to the inner surface of the magnetic body at the position where the internal defect is to be inspected, which is a feature of the second aspect of the invention, and a method of demagnetizing the residual magnetism of the magnetic body and reducing No magnetic field forming coil that applies a uniform magnetic field to the inner surface at the internal defect inspection position is described.
[0018]
[Non-patent document 1]
Industrial Materials June 1998 (Vol. 46 No. 6) "Magnetic Properties and Material Evaluation (Part 4)"
[0019]
[Non-patent document 2]
T. IEEE Japan 115, 10, 1995 (1955) 968 to 973
[0020]
[Problems to be solved by the invention]
The inspection example described in the prior art 1 focuses on the fact that when a defect occurs inside the magnetic body, the residual magnetic charge (coercive force) changes, and the defect inside the magnetic body is described as “ Since the "magnetic property change" is detected by the detection coil, even if the position of the defect inside the magnetic body can be detected, the defect state of the internal defect cannot be determined.
[0021]
In the measuring method for detecting the position of the rebar of the different diameter in the concrete of the prior art 2 (rebar buried in the test piece), since the leakage magnetic flux due to the remanent magnetization is detected by the detection coil, the inside of the magnetic body is detected. Even if the position of the defect can be detected, it is not possible to determine the defect state of the internal defect.
[0022]
An object of the first invention is to use a magnetic dipole of a steel core of a steel core cable having no residual magnetism without using a “magnetic property change” of a magnetic material caused by a defect inside the magnetic material. In a state where the steel core forms an aggregate of the magnetically charged magnetic dipoles, the SQUID sensor uses the SQUID sensor to detect the nonuniformity of the magnetic flux from the aggregated regions Ma, Mb, Mc,... Of the magnetically charged magnetic dipoles of the steel core cable. By detecting the defect, it is possible to determine not only the position of the defect inside the magnetic substance but also the defect state of the internal defect. "
[0023]
An object of the second invention is to provide a "magnetic field forming coil for applying a uniform magnetic field to the inner surface of a magnetic material at an internal defect inspection position" or "demagnetizing the residual magnetism of a magnetic material and an inner surface of the magnetic material at an internal defect inspection position." A magnetic field forming coil that applies a uniform magnetic field to the magnetic material can determine not only the position of the defect inside the magnetic material but also the defect state of the internal defect. "
[0024]
[Means for Solving the Problems]
[Embodiment of the first invention]
Embodiment 1 As shown in FIG. 7, a method for inspecting a defect of a steel core cable WK using a SQUID sensor 1 having a detection coil for detecting a change in an external magnetic flux as shown in FIG. In a state where the magnetic dipole M of the steel core of the WK bears a small magnetic charge and the steel core forms an aggregate MA of the magnetic dipoles with a small magnetic charge, the SQUID sensor 1 scans from the outer periphery of the steel core cable WK. .. Are sequentially stored, and the stored minute magnetic flux values are arranged in the order of continuous positions of the steel core cable WK. A continuous position sequential arrangement magnetic flux value is stored, and the continuous position sequential arrangement magnetic flux value is displayed at a continuous position of the steel core cable WK, and the continuous position sequential arrangement magnetic flux generated at a position where an internal defect of the steel core cable WK exists. From uneven values It is a non-destructive inspection method according SQUID sensor to determine the position and defect status serial internal defects are present.
[0025]
Embodiment 2 As shown in FIGS. 7 and 8, a method of inspecting a steel core cable WK for defects using a SQUID sensor 1 having a detection coil for detecting a change in external magnetic flux,
In a state where the magnetic dipole M of the steel core of the steel core cable WK having no residual magnetism bears a minute magnetic charge and the steel core forms an aggregate MA of the magnetic dipole magnetic dipole, the SQUID sensor 1 uses the steel core. An aggregated area of minute magnetically charged magnetic dipoles scanned by scanning a first scanning section of a predetermined width ΔW and a predetermined length L from the outer periphery of the cable WK in the length direction of the steel core cable WK. .. Are sequentially stored in the first scanning section detected from Ma, Mb, Mc,.
Next, the second scanning section adjacent to the first scanning section is scanned from the outer circumference in the diameter direction of the steel core cable WK, and the aggregated areas Ma, Mb, Mc of the scanned micro-magnetic dipoles are scanned. ,... Are sequentially stored in the second scanning section, and
Hereinafter, the third to Nth scanning sections adjacent to the second to (N-1) th scanning sections in the diameter direction of the steel core cable WK are sequentially scanned from the outer circumference, and the scanned minute magnetic charge magnetism is scanned. .. Are sequentially stored in the third scanning section through the Nth scanning section detected from the dipole assembly areas Ma, Mb, Mc,.
The first to Nth scanning section minute magnetic flux values are arranged in the diametric direction of the steel core cable WK, and the successively arranged magnetic flux values of the first to Nth scanning sections are stored.
By displaying the magnetic flux values at the consecutive positions in the first to Nth scanning sections at successive positions of the steel core cable WK,
This is a nondestructive inspection method using a SQUID sensor that determines the position where the internal defect exists and the state of the defect based on the non-uniformity of the magnetic flux values in the continuous position order at the position where the internal defect of the steel core cable WK exists.
[0026]
Embodiment 3 is a method for inspecting a steel core cable WK for defects using the SQUID sensor 1 having a detection coil for detecting a change in external magnetic flux,
In the state where the magnetic dipole M of the steel core of the steel core cable WK having no residual magnetism bears a minute magnetic charge and the steel core forms the aggregate MA of the magnetic dipole magnetic dipole, the steel core cable length direction SQUID sensor 1 in a detection coil cable length orthogonal direction (Y-axis direction) orthogonal to the length direction (X-axis direction) of steel core cable WK and the central axis (Z-axis direction) of the detection coil. And the steel core cable WK are relatively moved to sequentially store the minute magnetic flux values detected from the aggregate regions Ma, Mb, Mc,... Of the minute magnetically charged magnetic dipoles,
The minute magnetic flux value is read out to detect a two-dimensional plane formed by the length direction of the cable (X-axis direction) and the central axis of the detection coil (Z-axis direction) or the length direction of the cable (X-axis direction). A three-dimensional three-dimensionally arranged continuous position order magnetic flux value formed by a center axis (Z-axis direction) of the coil and the detection coil cable length orthogonal direction (Y-axis direction) is stored.
Reading the magnetic flux values in the continuous position order, displaying the magnetic flux distribution corresponding to the cable position in the two-dimensional plane or the three-dimensional plane,
Due to the non-uniformity of the magnetic flux value in the continuous position sequence, which is generated at the position where the internal defect of the steel core cable WK exists, each position in the length direction of the steel core cable WK and the inside of the detection coil cable length orthogonal direction (Y-axis direction). This is a nondestructive inspection method using a SQUID sensor for determining a defect state of a defect.
[0027]
Embodiment 4 is a method for inspecting a defect of a steel core cable WK using a SQUID sensor 1 having a detection coil for detecting a change in an external magnetic flux,
In a state where the magnetic dipole M of the steel core of the steel core cable WK having no residual magnetism bears a minute magnetic charge and the steel core forms the aggregate MA of the magnetic dipole magnetic dipoles, the length of the steel core cable is In the direction (X-axis direction) and the detection coil cable length orthogonal direction (Y-axis direction) orthogonal to the length direction (X-axis direction) of the steel core cable and the center axis (Z-axis direction) of the detection coil, the SQUID sensor The relative movement between the steel core cable and the micro magnetic flux detection signal 1s detected from the assembly areas Ma, Mb, Mc,... An A / D converter step for outputting a signal 11s;
The magnetic flux digital signal 11s is input and a two-dimensional plane formed by the length direction of the cable (X-axis direction) and the central axis of the detection coil (Z-axis direction) or the length direction of the cable (X-axis direction) An image that outputs the imaging processing signal 12s after being arranged and stored in a three-dimensional three-dimensional plane formed by the center axis of the detection coil (Z-axis direction) and the detection coil cable length orthogonal direction (Y-axis direction). Processing step;
A compositing step of inputting the image processing signal 12s and outputting a differential signal 13s obtained in the length direction of the steel core cable by using the magnetic field distribution inclination correcting means;
A measurement screen memory step of receiving the difference signal 13s and outputting a measurement screen memory signal 14s;
A measurement screen comparison signal which receives the measurement screen memory signal 14s and outputs a measurement screen comparison signal 15s obtained by comparing three-dimensional image data with reference data which is image data of a magnetic field generated from a predetermined sound portion of the steel core cable. Steps and
Inputting the measurement screen comparison signal 15s and displaying it on the measurement image display mechanism 16.
A SQUID sensor that determines that the steel core cable is internally deteriorated when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed as being distorted because the magnetic field is lower than the image data of the magnetic field generated from the healthy portion. Is a non-destructive inspection method.
[0028]
Embodiment 5 is described in Embodiments 1 to 4 when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is lower and distorted than the image data of the magnetic field generated from the sound portion. Is a non-destructive inspection method using a SQUID sensor that determines the position where the internal defect exists and the defect state from the non-uniformity of the magnetic flux value in the continuous position order.
[0029]
Embodiment 6 As shown in FIG. 1, the sixth embodiment is a device for non-destructively inspecting the internal deterioration phenomenon of a steel core cable three-dimensionally using a SQUID sensor, and uses a second-order differential DC-SQUID gradiometer 1. The cooling means 2 for cooling the SQUID sensor and the magnetic dipole M of the steel core of the steel core cable WK having no residual magnetism bear a minute magnetic charge, and the steel core forms an aggregate MA of the minute magnetically charged magnetic dipoles. In this state, the change of the magnetic field obtained by scanning the steel core cable two-dimensionally is processed as three-dimensional image data, and the three-dimensional image data and the image of the magnetic field generated from a predetermined sound portion of the steel core cable are processed. This is a nondestructive inspection device using a SQUID sensor including an image processing means PC for three-dimensionally judging a steel core cable by comparing with reference data which is data.
[0030]
In the seventh embodiment, the image processing unit PC according to the sixth embodiment performs a process of converting the differential signal 13s obtained in the line direction of the steel core cable into image data using convolution integration as a magnetic field distribution inclination correction unit. This is a non-destructive inspection device using a SQUID sensor.
[0031]
In an eighth embodiment, the image processing means PC according to the sixth embodiment compares the data subjected to the inclination correction processing of the magnetic field distribution with reference data which is image data of a magnetic field generated from a sound portion of a predetermined steel core cable. When the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is lower than the image data of the magnetic field generated from the sound portion and displayed in a distorted state, the SQUID is determined to be the internal deterioration of the steel core cable. This is a non-destructive inspection device using sensors.
[0032]
Embodiment 9 is an inspection apparatus for inspecting a defect of a steel core cable WK using the SQUID sensor 1 including a detection coil for detecting a change in external magnetic flux,
The SQUID sensor is connected to the steel core cable in the length direction of the steel core cable on the surface of the steel core cable and in the detection coil cable length orthogonal direction orthogonal to the length direction of the steel core cable and the center axis of the detection coil. In a state in which the magnetic dipoles M of the steel core of the steel core cable WK having no remanence are charged with a minute magnetic charge and the steel core forms an aggregate MA of the magnetic dipoles with a small magnetic charge, the SQUID is moved relatively. The sensor 1 scans from the outer periphery of the steel core cable WK to detect the minute magnetic flux signal 1 s detected from the aggregate areas Ma, Mb, Mc,... Of the minute magnetically charged magnetic dipoles, and the minute magnetic flux detection signal detected by the SQUID sensor. An A / D converter 11 for digitizing 1 s and sequentially outputting a magnetic flux digital signal 11 s;
By inputting the magnetic flux digital signal 11s, a two-dimensional plane (Y-axis and Z-axis plane) formed by the length direction of the cable (Y-axis direction) and the central axis of the detection coil (Z-axis direction) A three-dimensional surface (Y axis, Z axis plane, and X axis) formed by the length direction (Y axis direction), the center axis of the detection coil (Z axis direction), and the detection coil cable length orthogonal direction (X axis direction). An imaging processing circuit 12 that outputs an imaging processing signal 12s after arranging and storing the imaging processing signals in a Z-axis plane) and
A composition 13 which receives the imaging processing signal 12s and outputs a difference signal 13s obtained in the length direction of the steel core cable by using the inclination correction means of the magnetic field distribution,
A measurement screen memory 14 for receiving the differential signal 13s and outputting a measurement screen memory signal 14s;
A measurement screen comparison signal which receives the measurement screen memory signal 14s and outputs a measurement screen comparison signal 15s obtained by comparing three-dimensional image data with reference data which is image data of a magnetic field generated from a predetermined sound portion of the steel core cable. With the circuit 15,
A measurement image display mechanism 16 for inputting and displaying the measurement screen comparison signal 15s,
A SQUID sensor that determines that the steel core cable is internally deteriorated when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed as being distorted because the magnetic field is lower than the image data of the magnetic field generated from the healthy portion. Is a non-destructive inspection device.
[0033]
Embodiment 10 is an inspection apparatus that inspects a steel core cable WK for defects using the SQUID sensor 1 including a detection coil that detects a change in external magnetic flux.
In a state where the magnetic dipole M of the steel core of the steel core cable WK having no residual magnetism bears a minute magnetic charge and the steel core forms an aggregate MA of the magnetic dipole magnetic dipole, the SQUID sensor 1 uses the steel core. An aggregated area of minute magnetically charged magnetic dipoles scanned by scanning a first scanning section of a predetermined width ΔW and a predetermined length L from the outer periphery of the cable WK in the length direction of the steel core cable WK. A first scanning section minute magnetic flux value storage circuit for sequentially storing the first scanning section minute magnetic flux values detected from Ma, Mb, Mc,.
Next, the second scanning section adjacent to the first scanning section is scanned from the outer circumference in the diameter direction of the steel core cable WK, and the aggregated areas Ma, Mb, Mc of the scanned micro-magnetic dipoles are scanned. , A second scanning section minute magnetic flux value storage circuit for sequentially storing the second scanning section minute magnetic flux values detected from.
Hereinafter, the third to Nth scanning sections adjacent to the second to (N-1) th scanning sections in the diameter direction of the steel core cable WK are sequentially scanned from the outer circumference, and the scanned minute magnetic charge magnetism is scanned. A third to Nth scanning section minute magnetic flux value storage circuit for sequentially storing the third to Nth scanning section minute magnetic flux values detected from the dipole assembly areas Ma, Mb, Mc,.
In the first to Nth scanning sections, the minute magnetic flux values of the first to Nth scanning sections are arranged in the diameter direction of the steel core cable WK, and the magnetic flux values are sequentially arranged in the first to Nth scanning sections. A continuous arrangement magnetic flux storage circuit,
The minute detection magnetic flux signal 1s obtained by measuring the magnetic flux values in the consecutive positions in the first to Nth scanning sections at successive positions of the steel core cable WK is converted into a minute magnetic flux detection signal 1s detected by the SQUID sensor, and sequentially. An A / D converter 11 that outputs a magnetic flux digital signal 11s;
By inputting the magnetic flux digital signal 11s, a two-dimensional plane (Y-axis and Z-axis plane) formed by the length direction of the cable (Y-axis direction) and the central axis of the detection coil (Z-axis direction) A three-dimensional surface (Y axis, Z axis plane, and X axis) formed by the length direction (Y axis direction), the center axis of the detection coil (Z axis direction), and the detection coil cable length orthogonal direction (X axis direction). An imaging processing circuit 12 that outputs an imaging processing signal 12s after arranging and storing the imaging processing signals in a Z-axis plane) and
A composition 13 which receives the imaging processing signal 12s and outputs a difference signal 13s obtained in the length direction of the steel core cable by using the inclination correction means of the magnetic field distribution,
A measurement screen memory 14 for receiving the differential signal 13s and outputting a measurement screen memory signal 14s;
A measurement screen comparison signal which receives the measurement screen memory signal 14s and outputs a measurement screen comparison signal 15s obtained by comparing three-dimensional image data with reference data which is image data of a magnetic field generated from a predetermined sound portion of the steel core cable. A circuit 15;
A measurement image display mechanism 16 for inputting and displaying the measurement screen comparison signal 15s,
A SQUID sensor that determines that the steel core cable is internally deteriorated when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed as being distorted because the magnetic field is lower than the image data of the magnetic field generated from the healthy portion. Is a non-destructive inspection device.
[Embodiment of Second Invention]
Embodiment 11 is a method for inspecting an internal deterioration phenomenon of a steel core cable using a SQUID sensor, in which the SQUID sensor is scanned on the surface of the steel core cable, and a change in a magnetic field generated from an applied magnetic field is calculated. This is a nondestructive inspection method using a SQUID sensor for inspecting the internal deterioration phenomenon of the steel core cable by processing the calculated change in the magnetic field as image data.
[0034]
In a twelfth embodiment, when the image data according to the eleventh embodiment is deterioration phenomenon data obtained by detecting and processing an internal deterioration phenomenon of a steel core cable, the image displayed by processing the deterioration phenomenon data is a steel steel cable. This is a nondestructive inspection method using a SQUID sensor in which image data of a magnetic field generated from a deteriorated portion of a core cable is displayed in a state where the magnetic field is lower and distorted than image data of a magnetic field generated from a healthy portion.
[0035]
Embodiment 13 As shown in the block diagram of the inspection device in FIG. 9, a method for inspecting the internal deterioration phenomenon of the steel core cable using the SQUID sensor,
Detection of the SQUID sensor on the surface of the steel core cable at right angles to the length direction of the steel core cable (X-axis direction), the length direction of the steel core cable (X-axis direction), and the center axis of the detection coil (Z-axis direction). The SQUID sensor and the steel core cable are moved relative to each other in the direction orthogonal to the coil cable length (Y-axis direction), and the minute magnetic flux detection signal 1s in which the change in the magnetic field generated from the applied magnetic field is detected by the SQUID sensor is sequentially digitized. An A / D converter step for outputting a magnetic flux digital signal 11s;
The magnetic flux digital signal 11s is input and a two-dimensional plane formed by the length direction of the cable (X-axis direction) and the central axis of the detection coil (Z-axis direction) or the length direction of the cable (X-axis direction) An image that outputs the imaging processing signal 12s after being arranged and stored in a three-dimensional three-dimensional plane formed by the center axis of the detection coil (Z-axis direction) and the detection coil cable length orthogonal direction (Y-axis direction). Processing step;
A compositing step of inputting the image processing signal 12s and outputting a differential signal 13s obtained in the length direction of the steel core cable by using the magnetic field distribution inclination correcting means;
A measurement screen memory step of receiving the difference signal 13s and outputting a measurement screen memory signal 14s;
A measurement screen comparison signal which receives the measurement screen memory signal 14s and outputs a measurement screen comparison signal 15s obtained by comparing three-dimensional image data with reference data which is image data of a magnetic field generated from a predetermined sound portion of the steel core cable. Steps and
Inputting the measurement screen comparison signal 15s and displaying it on the measurement image display mechanism 16.
A SQUID sensor that determines that the steel core cable is internally deteriorated when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed as being distorted because the magnetic field is lower than the image data of the magnetic field generated from the healthy portion. Is a non-destructive inspection method.
[0036]
Embodiment 14 As shown in FIG. 9, as shown in FIG. 9, a three-dimensional nondestructive inspection device for the internal deterioration phenomenon of a steel core cable using a SQUID sensor, and uses a second-order differential type DC-SQUID gradiometer 1. A cooling means 2 for cooling the SQUID sensor, a magnetic field forming coil 4 arranged to demagnetize the residual magnetism of the steel core cable and to provide a uniform magnetic field, which is disposed in the vicinity of inspecting an internal defect of the steel core cable; A magnetic field change obtained by scanning the cable two-dimensionally is processed as three-dimensional image data, and the three-dimensional image data and reference data, which is image data of a magnetic field generated from a sound portion of a predetermined steel core cable, are converted. This is a nondestructive inspection device using a SQUID sensor including an image processing means PC for three-dimensionally judging a steel core cable by comparison.
[0037]
In a fifteenth embodiment, the image processing unit PC according to the fourteenth embodiment performs the process of converting the differential signal 13s obtained in the line direction of the steel core cable into image data using convolution integration as a gradient correction unit of the magnetic field distribution. This is a non-destructive inspection device using a SQUID sensor.
[0038]
In the sixteenth embodiment, the image processing means PC according to the fourteenth embodiment compares the data subjected to the inclination correction processing of the magnetic field distribution with reference data which is image data of a magnetic field generated from a sound portion of a predetermined steel core cable. When the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is lower than the image data of the magnetic field generated from the sound portion and displayed in a distorted state, the SQUID is determined to be the internal deterioration of the steel core cable. This is a non-destructive inspection device using sensors.
[0039]
Embodiment 17 is an apparatus for non-destructively inspecting the internal deterioration phenomenon of a steel core cable three-dimensionally using a SQUID sensor as shown in FIG.
The SQUID sensor is connected to the steel core cable in the length direction of the steel core cable on the surface of the steel core cable and in the detection coil cable length orthogonal direction orthogonal to the length direction of the steel core cable and the center axis of the detection coil. In a state where there is no residual magnetism in the steel core cable or in a state where the residual magnetism has been demagnetized by moving the steel core cable relative to each other, a uniform magnetic field is applied to the steel core cable to generate a leakage magnetic flux from the steel core cable. An A / D converter 11 for digitizing the magnetic flux detection signal 1s and sequentially outputting a magnetic flux digital signal 11s;
By inputting the magnetic flux digital signal 11s, a two-dimensional plane (Y-axis and Z-axis plane) formed by the length direction of the cable (Y-axis direction) and the central axis of the detection coil (Z-axis direction) A three-dimensional surface (Y axis, Z axis plane, and X axis) formed by the length direction (Y axis direction), the center axis of the detection coil (Z axis direction), and the detection coil cable length orthogonal direction (X axis direction). An imaging processing circuit 12 that outputs an imaging processing signal 12s after arranging and storing the imaging processing signals in a Z-axis plane) and
A composition 13 which receives the imaging processing signal 12s and outputs a difference signal 13s obtained in the length direction of the steel core cable by using the inclination correction means of the magnetic field distribution,
A measurement screen memory 14 for receiving the differential signal 13s and outputting a measurement screen memory signal 14s;
A measurement screen comparison signal which receives the measurement screen memory signal 14s and outputs a measurement screen comparison signal 15s obtained by comparing three-dimensional image data with reference data which is image data of a magnetic field generated from a predetermined sound portion of the steel core cable. A circuit 15;
A measurement image display mechanism 16 for inputting and displaying the measurement screen comparison signal 15s,
A SQUID sensor that determines that the steel core cable is internally deteriorated when the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed as being distorted because the magnetic field is lower than the image data of the magnetic field generated from the healthy portion. Is a non-destructive inspection device.
[0040]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment of the Invention]
Hereinafter, an embodiment of the first invention will be described with reference to FIG. The same or corresponding parts described in FIGS. 2 to 8 are denoted by the same reference numerals, and description thereof will not be repeated.
[0041]
FIG. 1 is a block diagram of a non-destructive inspection device that implements the non-destructive inspection method of the present invention using a SQUID sensor, and is a block diagram of the non-destructive inspection device of the present invention. In the figure, a steel core cable WK having no residual magnetism is arranged below a cryostat 2 which is cooled to about 4K at which a superconducting phenomenon occurs in the SQUID sensor.
[0042]
The method and apparatus according to the first invention have no residual magnetism without using the “magnetic property change” of the magnetic material caused by the position of the magnetic material or a defect inside the magnetic material as in the related art 1 or 2. A uniform magnetic field is applied to the steel core cable in a state where the steel core cable is in a demagnetized state, and the magnetic dipole M of the steel core of the steel core cable having no residual magnetism bears a minute magnetic charge, and the steel core has a minute magnetic charge magnetic dipole. In the state where the aggregate MA of the coils is formed, the non-uniformity of the minute magnetic flux is detected by the SQUID sensor from the aggregate regions Ma, Mb, Mc,... Of the minute magnetically charged magnetic dipoles of the steel core cable. It is possible to determine not only the position of the defect inside the core cable but also the defect state of the internal defect.
[0043]
In the figure, when there is residual magnetism in the steel core cable WK as a sample, a demagnetizing current is applied to the magnetic field forming coil 4 before the inspection to demagnetize. A small magnetic flux detection signal 1s which is obtained by scanning the surface of the steel core cable WK two-dimensionally with a second-order differential type DC radiometer 1 cooled by a cryostat 2 which cools the surface of the steel cable WK to about 4K to cause a superconducting phenomenon in the SQUID sensor. Is output to the sensor drive circuit 5.
[0044]
The sensor / cable relative moving mechanism 10 scans the SQUID sensor 1 and the steel core cable WK with the steel core cable in the length direction (Y-axis direction) and the steel core cable WK in order to scan the detection section of the steel core cable WK with the SQUID sensor. Move the SQUID sensor or the steel core cable or both in the orthogonal direction (X-axis direction) of the detection coil cable orthogonal to the length direction of the core cable (Y-axis direction) and the center axis of the detection coil (Z-axis direction) (relative Move).
[0045]
The A / D converter 11 converts the detected magnetic flux output signal 5s output from the sensor drive circuit 5 into a digital signal and outputs a digital magnetic flux signal 11s. The digital magnetic flux signal 11s is input, image-processed as three-dimensional image data, and output to image processing means PC for displaying a measurement image.
[0046]
The sensor driving circuit 5 supplies (outputs) a bias current for sensor (electrical) driving output from the control power supply circuit 9, a feedback signal for providing linearity to the SQUID sensor, and detects the SQUID sensor ( A minute magnetic flux detection signal 1s (detected from a steel core cable that may be deteriorated) is input, and signal level conversion, noise removal, signal selection, etc. are performed, and a detected magnetic flux output signal 5s required for residual magnetic position display is output. . The control power supply circuit 9 converts the commercial power supply voltage into a control power supply voltage for detection coil correction, sensor (electric) drive, demagnetization, formation of a measurement magnetic field, and the like, and outputs the control power supply voltage.
[0047]
In the present invention, a personal computer PC is used as the image processing means PC from the input of the digital magnetic flux signal 11s to the display of the measured image. The personal computer PC inputs the digital magnetic flux signal 11 s to the imaging processing circuit 12, and converts the imaging processing signal 12 s obtained by performing the imaging processing into a composition (convolution integration) by the composition 13. In this composition, a difference signal 13s obtained in the length direction of the steel core cable is output as a means for correcting the inclination of the magnetic field distribution. The difference signal 13s is stored in the measurement screen memory 14.
[0048]
The imaging processing circuit 12 receives the digital magnetic flux signal 11 s and scans and detects the non-uniformity of the leakage magnetic flux generated at the position where the internal defect of the steel core cable exists, and detects the magnetic flux change in the cable length direction (Y-axis direction). ) And the center axis (Z-axis direction) of the detection coil, or on the two-dimensional plane (Y-axis and Z-axis planes) or in the length direction of the cable (Y-axis direction) and the center axis of the detection coil (Z-axis direction). ) And the above detection coil cable length orthogonal direction (X axis direction), and outputs an imaging processing signal 12s for displaying in a three-dimensional three-dimensional plane (Y axis and Z axis plane and X axis and Z axis plane). I do.
[0049]
The image processing means PC outputs a measurement screen comparison signal 15 s obtained by comparing the three-dimensional image data with reference data which is image data of a magnetic field generated from a sound portion of a predetermined steel core cable by a measurement screen comparison circuit 15. It is displayed on the display mechanism 16 to determine the three-dimensional steel core cable.
[0050]
In the measurement image display mechanism 16 which receives the measurement screen comparison signal 15s as input, the image data of the magnetic field generated from the internally deteriorated portion of the steel core cable is displayed with the magnetic field reduced and distorted compared to the image data of the magnetic field generated from the healthy portion. When this is done, it is determined that the internal deterioration of the steel core cable has occurred.
[0051]
As described above, the basic configuration of the first invention, which is different from the related art 1 or the related art 2, is the “magnetic characteristic” of the magnetic body caused by a defect inside the magnetic body as in the related art 1 or the related art 2. In the state of demagnetization without using "change", "the magnetic dipole M of the steel core of the steel core cable having no residual magnetism bears a minute magnetic charge, and the steel core forms the aggregate MA of the magnetic dipoles of the minute magnetic charge. In this state, by detecting the non-uniformity of the minute magnetic flux from the aggregate regions Ma, Mb, Mc,... Of the minute magnetically charged magnetic dipoles of the steel core cable with the SQUID sensor, the position of the defect inside the magnetic material is determined. Of course, the defect state of the internal defect is also determined. "
[0052]
FIG. 7 is a diagram illustrating a magnetic field dipole for explaining the aggregate regions Ma, Mb, Mc,... Of the magnetic dipoles M of the steel core of the steel core cable WK. It is a schematic diagram of a child aggregate area Ma, Mb, Mc,... In the figure, the magnetic dipoles M are individually magnetic dipoles with a minute magnetic charge, but the aggregate MA of the magnetic dipoles has no remanence. That is, in order to apply the present invention, there must be no residual magnetism as in the prior art.
[0053]
An aggregate MA of magnetic dipoles to which the present invention is applied is, for example, an aggregate of magnetically charged magnetic dipoles which is the minimum detection range (resolution) of the detection coil when the detection coil of the SQUID sensor 1 is stopped. Are formed from body regions (hereinafter, referred to as magnetically charged dipole aggregate regions) Ma, Mb, Mc,... The SQUID sensor 1 scans from the outer periphery of the steel core cable WK to measure the aggregated magnetic flux value of the respective minute magnetic fluxes of the aggregate regions Ma, Mb, Mc,... Of the minute magnetically charged magnetic dipoles.
[0054]
Each of the minutely aggregated magnetic flux values of the aggregate regions Ma, Mb, Mc,... Of the minutely charged magnetic dipoles is, as shown in the later-described embodiment of FIGS. The position where the internal defect exists and the defect state can be determined because the position becomes uneven at the position where the defect exists.
[0055]
FIG. 8 is a view for explaining the magnitude of the magnetic flux values arranged in the continuous positions of the first to Nth scanning sections by arranging the minute magnetic flux values in the first scanning section to the Nth scanning section in the diameter direction of the steel core cable WK. FIG. 11 is a data diagram of a magnetic flux value difference-processed data sequentially arranged in the first to Nth scanning section continuous positions. 7, the same reference numerals as in FIG. 7 denote the same parts as in FIG. 7, but the description will be made on the assumption that there is an internal defect (crack) in the magnetic dipole aggregate MA.
[0056]
The SQUID sensor 1 scans a first scanning section of a predetermined width ΔW and a predetermined length L in the length direction of the steel core cable WK from the outer periphery of the steel core cable WK, and scans the minute magnetic charge magnetism. The micro magnetic flux value in the first scanning section detected from the dipole assembly regions Ma, Mb, Mc,... Is measured. Next, the second scanning section adjacent to the first scanning section is scanned from the outer circumference in the diameter direction of the steel core cable WK, and the aggregated areas Ma, Mb, Mc of the scanned micro-magnetic dipoles are scanned. ,... Are sequentially detected in the second scanning section. Hereinafter, the third to Nth scanning sections adjacent to the second to (N-1) th scanning sections in the diameter direction of the steel core cable WK are sequentially scanned from the outer circumference, and the scanned minute magnetic charge magnetism is scanned. .. Are detected sequentially from the third to Nth scanning sections detected from the dipole assembly areas Ma, Mb, Mc,. The minute magnetic flux values of the first scanning section to the Nth scanning section are arranged in the diameter direction of the steel core cable WK, and the magnetic flux values are sequentially arranged in the first to Nth scanning sections.
[0057]
The numbers for each of the magnetically charged dipole aggregate regions (Ma, Mb, Mc,...) In the enlarged view of the same figure are obtained by differentiating the detected magnetic flux value by applying the later described composition filter of FIGS. It is the example data processed. The numbers "0" to "3" assume the weighting of the detected magnetic flux value from small to large. “0” indicates a state where the detected magnetic flux value is “not detectable” in the portion of the aluminum stranded wire, “1” indicates a state where the detected magnetic flux value is “very weak”, “2” indicates a state where the detected magnetic flux value is “large”, and “3”. "Assumes that the detected magnetic flux value is" maximum. " As described above, when an internal defect (crack) exists in the magnetic dipole aggregate MA, the continuous arrangement magnetic flux becomes uneven, and the continuous position sequential arrangement magnetic flux value generated at the position where the internal defect of the steel core cable WK exists is present. The position where the internal defect exists and the defect state can be determined from the unevenness.
[Embodiment of second invention]
Hereinafter, an embodiment of the present invention will be described with reference to FIG. The same or corresponding portions described in FIGS. 2 to 6 are denoted by the same reference numerals, and description thereof will not be repeated.
[0058]
The method and apparatus according to the second aspect of the present invention provide a demagnetized state without using “magnetic property change” of a magnetic body caused by a position of the magnetic body or a defect inside the magnetic body as in the related art 1 or 2. When a uniform magnetic field is applied to the steel core cable, the position of the defect inside the steel core cable becomes Of course, it is possible to determine even the defect state of the internal defect.
[0059]
In the figure, a steel core cable WK as a sample is demagnetized by applying a demagnetizing current to the magnetic field forming coil 4 before inspection. A small magnetic flux detection signal 1s which is obtained by scanning the surface of the steel core cable WK two-dimensionally with a second-order differential type DC radiometer 1 cooled by a cryostat 2 which cools the surface of the steel cable WK to about 4K to cause a superconducting phenomenon in the SQUID sensor. Is output to the sensor drive circuit 5.
[0060]
Hereinafter, since it is the same as that of FIG. 1 described above, the description of FIG. 9 is omitted.
In the embodiment of the second invention, the basic configuration different from the prior art 1 or the prior art 2 is as described above, as described in the prior art 1 or the prior art 2, in that the magnetic material generated by a defect inside the magnetic material is used. In a state where demagnetization is performed without using the “magnetic property change”, a uniform magnetic field is applied to the steel core cable, and the magnetic flux becomes uneven at locations where there is a defect inside the steel core cable, resulting in leakage magnetic flux Therefore, the following configuration is added.
[0061]
In the present invention, a magnetic field forming coil 4 for demagnetizing the remanence of the steel core cable and providing a uniform magnetic field to be provided near the inside of the steel core cable for inspecting internal defects, and demagnetizing the remanence to the magnetic field forming coil 4 A demagnetizing current to generate a uniform magnetic field and a measuring magnetic field current to generate a uniform magnetic field are applied to the steel core cable. A magnetic field current generating circuit 20 for generating a leakage magnetic flux from the cable and supplying a demagnetizing current and a measured magnetic field current is added.
[0062]
Since the “input coil” described in the prior art 1 or 2 is arranged coaxially (in the Z-axis direction) with the detection coil, it can apply a magnetic field only from the outer peripheral direction of the steel core cable. . On the other hand, since the central axis of the magnetic field forming coil 4 used in the present invention is arranged so as to be in the length direction (Y-axis direction) of the steel core cable, a uniform magnetic field is applied to the cross section of the steel core cable. be able to. Therefore, in the direction of the magnetic field provided by the “input coil” described in the prior art 1 or 2, a uniform magnetic field is applied to the cross section of the steel core cable like the magnetic field provided by the magnetic field forming coil 4 used in the present invention. Therefore, the object of the second invention cannot be achieved.
[Principle of the composition filter]
Hereinafter, “Difference calculation obtained in the length direction of the steel core cable by inputting the imaging processing signal 12s” described in the above-described fourth, ninth, tenth, thirteenth, and seventeenth embodiments will be described. The principle of a composition filter (hereinafter, referred to as a filter) which is a main part of the "composition 13 that outputs the signal 13s" will be described with reference to FIGS. It is also referred to as superposition integration or differentiation of compiling.
[Description of FIG. 10]
FIG. 10 is a diagram showing a relationship between image data and a filter in which the image data shown in FIG. (B) projected by the SQUID sensor is subjected to a difference processing by, for example, a filter in which an integer shown in FIG. is there.
[0063]
This filter is a type of smoothing filter that smoothes (smooths) variations in image data caused by noise, measurement errors, and the like in image processing. For example, an integer value shown in FIG. Perform the difference processing by the filter. The characteristics of the filter change depending on the numerical value assigned to the filter, and the filtered image data differs.
[0064]
The 9-point (pixel) filter shown in FIG. 10 (A) creates a 3 × 3 matrix screen, positions data weights (large and small levels) at 1.2.1, and arranges 9 pixels into vertical and horizontal pixels. By setting the values to have a relationship of 1.2.1, image data filtered by 25 points (5 × 5 pixels) shown in FIG.
[Description of FIGS. 11 to 18]
FIG. 11 is a diagram showing the relationship between the encoded image data and the filter for performing the difference processing on the encoded image data shown in FIG. 11B by the filter of the encoding variable shown in FIG. 11A. The 9-point (pixel) filter shown in FIG. 11A creates a screen of a 3 × 3 matrix, assigns data weights (large and small levels) to the encoding variables h1 to h9, and arranges the nine pixels vertically and horizontally. Image data of the coded data f1 to f25 that have been subjected to the 25-point (5 × 5 pixel) filtering shown in FIG.
[0065]
FIG. 12 shows that the filter of the coding variable shown in FIG. 11A is folded horizontally to generate the filter of FIG. 11B in order to perform convolution integration, and then the filter of FIG. FIG. 9 is a filter vertical / horizontal folding relation diagram in which the filter of FIG.
[0066]
FIG. 13 shows an image shown in FIG. 13C in which the vertical and horizontal folding filters h9 to h1 in FIG. 13A are overlapped so as to match the upper left corner of the image data f1 to f25 shown in FIG. This is the upper left filter superimposed image data that has generated the image data of the upper left filter superimposed on the data.
[0067]
The vertical / horizontal folding filter shown in FIG. 13A is the vertical / horizontal folding filter generated in FIG. 12C, and the image data 25 points of the encoded data f1 to f25 shown in FIG. (5 × 5 pixels) is the image data generated in FIG.
[0068]
FIG. 14 is a top left superimposed image showing the relationship between the image data generated in FIG. 13C and the pixel value recording data recording the pixel value g1 calculated at the overlapping position shown in FIG. It is a pixel data relation diagram.
[0069]
FIG. 15 shows the upper left pixel h9 of the vertical / horizontal folding filter h9 to h1 in FIG. 12C, as shown in FIG. 15A, in the second column from the upper left corner of the image data shown in FIG. 15 (B), and the superimposed image in the second column on the upper left showing the relationship with the pixel value recording data in which the pixel value g2 calculated at the overlapping position shown in FIG. 15B is recorded. It is a pixel data relationship diagram.
[0070]
FIG. 16 shows the upper left pixel h9 of the vertical / horizontal folding filter h9 to h1 in FIG. 12C, as shown in FIG. 16A, in the third column from the upper left corner of the image data shown in FIG. The upper left third column superimposed image showing the relationship with the pixel value recording data in which the pixel value g3 calculated at the overlapping position shown in FIG. 16B is superimposed so as to coincide with the pixel (f3) of FIG. It is a pixel data relationship diagram.
[0071]
FIG. 17 shows the upper left pixel h9 of the vertical / horizontal folding filter of h9 to h1 in FIG. 12C, as shown in FIG. 17A, in the second row from the upper left corner of the image data shown in FIG. The upper left two rows showing the relationship with the pixel value recording data in which the pixel value g4 calculated at the overlapping position shown in FIG. 17B is recorded so as to overlap with the pixel (f16) of (second row). FIG. 4 is a diagram showing a relation between a superimposed image and pixel data.
[0072]
FIG. 18 omits illustration of the upper left pixel h9 of the vertical / horizontal folding filter h9 to h1 in FIG. 12C, but sequentially shifts from the final upper left corner to the third column and the third row. FIG. 19 is a superimposed image / pixel data relationship diagram showing the relationship between the pixel value g9 calculated at the superimposition final position of the projection data shown in FIG. 18A and the recorded pixel value data.
[0073]
【Example】
FIG. 19 is a three-dimensional projection image data diagram showing image data obtained by three-dimensionally projecting a deteriorated steel core aluminum stranded wire described later by the SQUID sensor. The projected image data is differentiated by a filter to generate pixel data (not shown). Based on this pixel data, image data after filtering of FIG. 21 described later is generated.
[0074]
FIG. 20 is a diagram of the inclination correction / difference processing for performing the difference processing and the inclination correction on the three-dimensional projected image data of the steel core aluminum stranded wire. The white line of the image data in the vertical direction on the right side is a projected image data diagram in the cross-sectional (Y-axis) direction of the steel core aluminum stranded wire, and indicates that the magnetic flux density is high at the center. The white line in the image data in the lower horizontal direction is a projected image data diagram in the length (X-axis) direction of the steel core aluminum stranded wire, and indicates that the magnetic flux density changes in the length direction. .
[0075]
FIG. 21 is a filter coefficient table in which numerical values (composition filter coefficients) for weighting data are substituted. In the column direction X of the table, the weight of the central axis (Z-axis direction) of the SQUID sensor shown in FIG. 1 is set to 0, and both sides of the cross section are set to -1 and +1. In the row direction Y of the table, the weight of the central axis (Z-axis direction) of the SQUID sensor shown in FIG. 1 is set to 0, the passing side is set to -1, and the non-passing side is set to +1.
[0076]
FIG. 22 is a three-dimensional filtered image data diagram showing filtered image data generated by performing a tilt correction and a difference process on the three-dimensional projected image data of FIG. 19 using pixel data.
[0077]
The following example shows an example of implementing the method of the present invention using the inspection apparatus of the present invention shown in FIG. 1 or FIG. FIG. 23 is a cross-sectional view of a steel core aluminum stranded wire to be internally inspected by the SQUID sensor.
[0078]
FIG. 24A is a longitudinal sectional view of a steel core aluminum stranded wire that has not deteriorated. In the drawing, white portions at the upper and lower portions of the paper are aluminum stranded wires, and a plurality of central line segments are steel cores. FIG. 24B is a normal display diagram of the detected magnetic flux value when an internal inspection is performed by the SQUID sensor along the length direction of the unstretched steel core aluminum stranded wire. In the above detected magnetic flux value normal display diagram, the white portions at the top and bottom of the paper are the outer peripheral portion of the steel core and indicate that the detected magnetic flux value is low, and conversely, the black portion at the center is detected by the magnetic flux of the steel core. This indicates that the magnetic flux value is high.
[0079]
FIG. 25A is a longitudinal sectional view of a steel core aluminum stranded wire in which the steel core is corroded and the steel core cross section is reduced as indicated by the dotted line. In the drawing, white portions at the upper and lower portions of the paper are aluminum stranded wires, and a plurality of central line segments are steel cores. FIG. 25B shows the magnetic flux detected inside when the SQUID sensor performs an internal inspection along the length direction of the aluminum stranded wire of the steel core in which the steel core of FIG. FIG. 5 is a display diagram showing a decrease in an internally detected magnetic flux value showing a state in which the value has sharply decreased. In the above detected magnetic flux value drop display, the white portions at the top and bottom of the paper are the outer peripheral portion of the steel core and indicate that the detected magnetic flux value is low, and conversely, the black portion at the center is detected by the magnetic flux of the steel core. This indicates that the magnetic flux value is high.
[0080]
FIG. 26 (A) is a longitudinal sectional view of a steel core aluminum stranded wire in which a crack has occurred at one location on the outer circumference of the steel core and the magnetic flux path on the outer circumference has been interrupted, as indicated by the dotted line. FIG. 26 (B) shows an internal inspection using a SQUID sensor along the length direction of a steel core aluminum stranded wire in which a crack has occurred in the steel core in the upper part of the drawing of FIG. 25 (B) and the magnetic flux path on the outer periphery has been interrupted. FIG. 9 is a display diagram of the detected magnetic flux value of the outer periphery of the steel core showing a state where the detected magnetic flux value is reduced at the outer periphery of the steel core at the time.
[0081]
In the above steel core outer periphery detection magnetic flux value decrease display diagram, white portions at the top and bottom of the paper are the outer periphery of the steel core and indicate that the detected magnetic flux value is low, and conversely, the black portion at the center is the steel core. This indicates that the detected magnetic flux value is high due to the magnetic flux. Also, in the above display diagram, while the detected magnetic flux value is reduced at the outer periphery of the steel core in the white part at the top of the paper, the white part at the bottom of the paper is free from cracks in the steel core. This shows a state where the detected magnetic flux value does not decrease at the outer periphery of the steel core.
[0082]
In this way, while the crack occurs in the steel core on the upper side of the steel core outer circumference detection magnetic flux value drop display diagram and the magnetic flux path on the outer circumference is cut off, the steel core outer circumference detection magnetic flux value decreases, In the outer periphery where no crack is generated in the lower steel core in the figure, the magnetic flux passage is not interrupted, so that the detected magnetic flux value of the outer periphery of the steel core does not decrease. Therefore, the detected magnetic flux value of the outer circumference of the steel core on the upper side of the display diagram and the detected magnetic flux value of the outer circumference of the steel core on the lower side of the display diagram are asymmetric.
[0083]
FIG. 27 is a longitudinal sectional view of a steel core aluminum stranded wire in which the steel core has been corroded and the steel core cross section has been reduced, as indicated by the solid line. As shown in the longitudinal sectional view of this steel core aluminum stranded wire, the wires in the first and second layers from the outside are hard aluminum, and the wires in the third and center layers are steel. FIG. 27 shows a steel core aluminum stranded wire obtained by cutting the wire of the steel core of the third layer by 10 mm in width and 1.25 mm in depth and assuming corrosion deterioration at the position indicated by the symbol A.
[0084]
FIG. 28 is a cross-sectional detection magnetic flux obtained by two-dimensionally measuring a change state of an internal detection magnetic flux value when a cross section of the cross section in which the steel core is corroded and the steel core cross section is reduced is scanned by a SQUID sensor. FIG.
[0085]
A decrease in the detected magnetic flux value is observed at the assumed position of the deterioration of the steel core indicated by reference symbol A in FIG. 27, and the detected magnetic flux value changes in the diameter direction (X-axis direction). Further, also in the length direction (Y-axis direction), the position indicated by the symbol A in FIG. 28 is the center position of the concave portion cut assuming deterioration. On the other hand, the detected magnetic flux value at a position where deterioration of the steel core is not assumed is black in the length direction (X-axis direction), and the detected magnetic flux value is high and does not change.
[0086]
FIG. 29 shows three-dimensionally (three-dimensionally) the state of change in the detected magnetic flux value inside when the cross section in which the steel core corroded and the steel core cross section was reduced in FIG. 27 was three-dimensionally scanned by the SQUID sensor. It is the cross-section detection magnetic flux value drop display figure. The detected magnetic flux value decreases in the radial direction as indicated by the white color in the display diagram at the assumed deterioration position of the steel core. In the part where the steel core has not deteriorated, the detected magnetic flux value is black and the detected magnetic flux value is high and does not change. However, in the part where the steel core has deteriorated, the detected magnetic flux value has decreased to a white conical shape.
[0087]
As shown in the examples of FIGS. 24 (A) to 29, the steel core which is inside the aluminum stranded wire and cannot be seen from the outer periphery had corrosion, wire breakage, and deterioration such as cracks. Even in this case, if a uniform measuring magnetic field is formed on the steel core without the residual magnetism of the steel core, the detected magnetic flux value becomes non-uniform at the deteriorated position. For example, it is possible to determine whether the deterioration is corrosion, wire breakage, crack, or the like.
[0088]
The embodiments and examples disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0089]
【The invention's effect】
According to the first invention, the steel core of the steel core cable having no residual magnetism without the residual magnetism without using the “magnetic property change” of the magnetic material caused by a defect inside the steel core cable and without the residual magnetism In the state where the magnetic dipoles of the above have a small magnetic charge and the steel core forms an aggregate of the magnetically charged magnetic dipoles, the aggregate region Ma, By detecting the nonuniformity of the minute magnetic flux from Mb, Mc,..., It is possible to determine not only the position of the defect inside the magnetic material but also the defect state of the internal defect.
[0090]
According to the second invention, a uniform magnetic field is applied to the inner surface of the steel core cable at the internal defect inspection position in a demagnetized state without using the “magnetic property change” of the magnetic material caused by a defect inside the steel core cable. By giving the magnetic flux leakage from the steel core cable, it is possible to determine not only the position of the defect inside the steel core cable but also the defect state of the internal defect.
[Brief description of the drawings]
FIG. 1 is a block diagram of a nondestructive inspection device that implements the nondestructive inspection method of the first invention using a SQUID sensor, and is a block diagram of the nondestructive inspection device of the first invention.
FIG. 2 is a principle diagram of a detection coil of the SQUID sensor described in Prior Art 1.
FIG. 3 is an explanatory diagram when a reinforcing bar is detected by the SQUID sensor described in FIG.
4 is a diagram of a concrete embedded different diameter reinforcing bar showing a shape of a different diameter reinforcing bar of the test body described in FIG.
FIG. 5 is a schematic diagram of detection of the position of a buried reinforcing bar for detecting the position of the different-diameter reinforcing bar of the test body described in FIG.
FIG. 6 shows the distance between the center axis of the reinforcing bar in the outer circumferential direction and the detected voltage when the position of the different-diameter reinforcing bar of the test piece described in FIG. It is a reinforcing bar position detection voltage measurement diagram.
FIG. 7 is a schematic diagram of an area of a magnetic dipole assembly in which a magnetic dipole M of a steel core of the steel core cable bears a micro magnetic charge; .
FIG. 8 is a view for explaining a magnitude of a magnetic flux value arranged in a continuous position in the first to Nth scanning sections by arranging a minute magnetic flux value in the first scanning section to the Nth scanning section in the diameter direction of the steel core cable WK; FIG. 11 is a data diagram of a magnetic flux value difference-processed data sequentially arranged in the first to Nth scanning section continuous positions.
FIG. 9 is a block diagram of a non-destructive inspection device that implements a second non-destructive inspection method of the present invention using a SQUID sensor, and is a block diagram of a non-destructive inspection device of the second invention.
FIG. 10 is a relational diagram of image data and filters with constant substitution, in which image data shown in FIG. (B) projected by the SQUID sensor is subjected to a difference processing by a filter into which integer values shown in FIG.
11 is a diagram showing a relationship between encoded image data and a filter for performing a difference process on the encoded image data shown in FIG. 11B by a filter of an encoding variable shown in FIG. 11A.
FIG. 12 (A) folds FIG. 10 (A) in the horizontal direction to generate the filter in FIG. 10 (B) in order to perform convolution integration with the filter of the coding variable shown in FIG. It is a filter vertical-horizontal-folding relation diagram which folded and produced the filter of FIG.
13A and 13B, the vertical / horizontal folding filter shown in FIG. 13A is overlapped so as to coincide with the upper left corner of the image data shown in FIG. 13B, and the upper left filter of the image data shown in FIG. This is the upper left filter superimposed image data that generated the image data.
14 is an upper left superimposed image / pixel data relationship diagram showing a relationship between pixel values g1 calculated at the overlapping positions shown in FIG. 14A and pixel value recording data recorded.
15 is an upper left second column superimposed image / pixel data relationship diagram showing a relationship between pixel values g2 calculated at the overlapping position shown in FIG. 15A and pixel value recording data recorded.
FIG. 16 is an upper left third column superimposed image / pixel data relationship diagram showing a relationship between pixel value g3 calculated at the overlapping position shown in FIG. 16A and pixel value recording data.
FIG. 17 is an upper left second-stage superimposed image / pixel data relationship diagram showing a relationship between pixel values g4 calculated at the overlapping positions shown in FIG. 17A and pixel value recording data recorded.
FIG. 18A shows a pixel value calculated at the final position as shown in FIG. 18A by shifting the upper left pixel h9 of the vertical / horizontal folding filter sequentially from the final upper left corner to the third column and the third row. FIG. 11 is a superimposed image / pixel data relationship diagram showing a relationship with g9 recorded pixel value recording data.
FIG. 19 is a three-dimensional projection image data diagram showing image data obtained by projecting a steel core aluminum stranded wire three-dimensionally by the SQUID sensor.
FIG. 20 is a diagram illustrating a tilt correction / difference processing for performing a difference processing and a tilt correction on three-dimensional projection image data of a steel core aluminum stranded wire.
FIG. 21 is a filter coefficient table in which numerical values (composition filter coefficients) for weighting data are substituted.
FIG. 22 is a three-dimensional filtered image data diagram showing filtered image data generated by subjecting the three-dimensional projected image data of FIG. 19 to inclination correction and difference processing using pixel data.
FIG. 23 is a cross-sectional view of a steel core aluminum stranded wire to be internally inspected by a SQUID sensor.
FIG. 24 (A) is a longitudinal sectional view of an undegraded steel core aluminum stranded wire, and FIG. 24 (B) is a view of the undegraded steel core aluminum stranded wire along a longitudinal direction. FIG. 8 is a diagram showing a normal display of a detected magnetic flux value when an internal inspection is performed by a SQUID sensor.
FIG. 25 (A) is a longitudinal sectional view of a steel core aluminum stranded wire in which the steel core is corroded and the steel core cross section is reduced as shown by the dotted line, and FIG. 25 (B) is FIG. 25 ( FIG. 5A is a view showing a decrease in the detected internal magnetic flux value in a state in which the detected magnetic flux value is drastically reduced in the length direction of the steel core aluminum wire in which the steel core is corroded and the steel core cross section is reduced.
FIG. 26 (A) is a longitudinal sectional view of a steel core aluminum stranded wire in which a crack has occurred at one location on the outer circumference of the steel core and the magnetic flux path on the outer circumference has been interrupted as indicated by a dotted line, and FIG. 26 (B) shows a state in which a detected magnetic flux value has decreased at the outer circumference of the steel core in the length direction of the aluminum core wire in which cracks have occurred in the steel core of FIG. FIG. 6 is a diagram showing a display of a detected magnetic flux value of the outer periphery of the core.
FIG. 27 is a longitudinal cross-sectional view of a steel core aluminum stranded wire in which the steel core is corroded and the steel core cross section is reduced as indicated by the solid line.
28 is a cross-sectional detection magnetic flux obtained by two-dimensionally measuring a change state of an internal detection magnetic flux value when a cross-section of the cross-section of the steel core of FIG. 27 in which the steel core corrodes and the steel core cross-section is reduced is scanned by the SQUID sensor. FIG.
FIG. 29 shows a three-dimensional (three-dimensionally) three-dimensional (three-dimensionally) change state of an internal detected magnetic flux value when a cross section in which the steel core is corroded and the steel core cross section is reduced is three-dimensionally scanned by the SQUID sensor. It is the cross-section detection magnetic flux value drop display figure.
[Explanation of symbols]
1 SQUID sensor, 2 cryostat, 4 magnetic field forming coil, 5 sensor drive circuit, 9 control power supply circuit, 10 sensor / cable relative movement mechanism, 10A (conventional) rebar movement mechanism, 11 A / D converter, 12 imaging processing circuit , 13 composition, 14 measurement screen memory, 15 measurement screen comparison circuit, 16 measurement image display mechanism, 20 magnetic field current generation circuit, M magnetic dipole, MA aggregate of micro magnetically charged magnetic dipole, Ma, Mb, Mc, … Micro magnetic dipole assembly area, PC image processing means, WK steel core cable, 1s micro magnetic flux detection signal, 5s detection magnetic flux output signal, 11s magnetic flux digital signal, 12s imaging processing signal, 13s differentiation signal, 14s Measurement screen memory signal, 15 s measurement screen comparison signal, predetermined length of L aggregate MA, each of ΔW aggregate MA Predetermined width, EnuderutaW predetermined width of aggregate MA between.

Claims (7)

In a method of inspecting a steel core cable for defects using a superconducting quantum interference device having a detection coil for detecting a change in an external magnetic flux, a magnetic dipole of a steel core of a steel core cable having no residual magnetism causes a minute magnetic charge to be generated. With the steel core forming an aggregate of micro magnetic dipoles, scanning from the outer periphery of the steel core cable with a superconducting quantum interference device is detected from the aggregate region of micro magnetic dipoles The micro magnetic flux values are sequentially stored, and the stored micro magnetic flux values are arranged in a continuous position order in which the stored micro magnetic flux values are arranged in the order of the continuous positions of the steel core cable. Non-destruction by a superconducting quantum interference device that displays a magnetic flux value and determines a position and a defect state where the internal defect exists based on the non-uniformity of the magnetic flux value in the continuous position order generated at a position where the internal defect of the steel core cable exists Inspection Method. In a method of inspecting a steel core cable for defects using a superconducting quantum interference device having a detection coil for detecting a change in external magnetic flux,
In the state where the magnetic dipoles of the steel core of the steel core cable having no residual magnetism bear a minute magnetic charge and the steel core forms an aggregate of the magnetically charged magnetic dipoles, the length direction of the steel core cable and the steel core The superconducting quantum interference device and the steel core cable are moved relative to each other in the detection coil cable orthogonal direction perpendicular to the cable length direction and the central axis of the detection coil, and detection is performed from the aggregated region of the magnetically charged dipoles. The stored small magnetic flux values are sequentially stored,
The minute magnetic flux value is read out, and a two-dimensional plane formed by the length direction of the cable and the center axis of the detection coil is formed or the length direction of the cable, the center axis of the detection coil, and the direction orthogonal to the detection coil cable length are formed. The three-dimensional three-dimensionally arranged continuous position sequential arrangement magnetic flux value is stored,
By reading the magnetic flux value in the continuous position order and processing the magnetic flux distribution corresponding to the cable position in the two-dimensional plane or the three-dimensional plane as image data, the magnetic flux is generated at a position where an internal defect of the steel core cable exists. A non-destructive inspection method using a superconducting quantum interference device for determining a position in a length direction of a steel core cable and a defect state of an internal defect in a direction orthogonal to the length of the detection coil cable from the non-uniformity of the magnetic flux values in the continuous position order. Using a superconducting quantum interference device, a method for inspecting the internal deterioration phenomenon of a steel core cable, scanning the superconducting quantum interference device on the surface of the steel core cable, calculating the change in the magnetic field resulting from the applied magnetic field, A non-destructive inspection method using a superconducting quantum interference device that inspects the internal deterioration phenomenon of a steel core cable by processing the calculated change in magnetic field as image data. When the image data according to claim 2 or 3 is deterioration data obtained by detecting and processing an internal deterioration phenomenon of a steel core cable, an image displayed by processing the deterioration data is a steel core cable. A non-destructive inspection method using a superconducting quantum interference device in which image data of a magnetic field generated from a deteriorated portion of a cable has a lower magnetic field than image data of a magnetic field generated from a healthy portion and is distorted and displayed. A device for non-destructively inspecting the internal deterioration phenomenon of a steel core cable using a superconducting quantum interference device, comprising: a cooling means for cooling the superconducting quantum interference device using a second-order differential type DC radiometer; Is processed as three-dimensional image data, and the three-dimensional image data is compared with reference data, which is image data of a magnetic field generated from a sound portion of a predetermined steel core cable. A non-destructive inspection device using a superconducting quantum interference device, comprising: an image processing means for three-dimensionally judging an internal deterioration phenomenon of a steel core cable. 6. The superconducting quantum interference device according to claim 5, comprising a process of converting a difference signal obtained in the line direction of the steel core cable into image data using convolution integration as a magnetic field distribution inclination correcting means. Non-destructive inspection equipment. In an inspection device that inspects a steel core cable for defects using a superconducting quantum interference device having a detection coil that detects a change in external magnetic flux,
The superconducting quantum interference device is placed on the surface of the steel core cable in the length direction of the steel core cable and in the direction perpendicular to the length direction of the steel core cable and the center axis of the detection coil. A / D that relatively moves the core cable, scans the superconducting quantum interference device from the outer periphery of the steel core cable, digitizes the minute magnetic flux detection signal detected by the superconducting quantum interference device, and sequentially outputs a magnetic flux digital signal. A converter,
By inputting the magnetic flux digital signal, the two-dimensional plane formed by the length direction of the cable and the center axis of the detection coil or the length direction of the cable, the center axis of the detection coil, and the direction orthogonal to the length direction of the detection coil cable. An imaging processing circuit that outputs an imaging processing signal after being arranged and stored in a three-dimensional three-dimensional plane to be formed,
A composition for inputting the imaging processing signal and outputting a differential signal obtained with respect to the length direction of the steel core cable by using the inclination correction means of the magnetic field distribution,
A measurement screen memory for inputting the differential signal and outputting a measurement screen memory signal;
A measurement screen comparison circuit that inputs the measurement screen memory signal and outputs a measurement screen comparison signal that compares three-dimensional image data with reference data that is image data of a magnetic field generated from a sound portion of a predetermined steel core cable; With
A measurement image display mechanism for inputting and displaying the measurement screen comparison signal,
A superconducting quantum that determines that an internal deterioration of the steel core cable has occurred when the image data of the magnetic field generated from the internally degraded portion of the steel core cable is displayed lower and distorted than the image data of the magnetic field generated from the healthy portion. Non-destructive inspection equipment using interference elements.

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