JP4608666B2 - Deterioration diagnosis device for iron-based structures - Google Patents

Description

  The present invention relates to a deterioration diagnosis apparatus for iron-based structures, and is useful for, for example, inspection of corrosion and thinning of inner surfaces of pipe-shaped structures and iron-based transport pipes used as power towers.

For example, pipe-like structures such as those used in power transmission towers are iron-based, and therefore the pipe inner surface may be corroded or thinned. For such corrosion / thinning of the inner surface, visual inspection cannot be performed, and in the case of non-destructive inspection, for example, a method using a fiberscope is known.
However, with this inspection method, the objective lens attached to the tip tends to become dirty due to rust on the inner surface of the pipe, and the inner surface of the pipe is uneven due to rusting, making it difficult to smoothly insert the fiberscope into the pipe. There are problems with accuracy and workability.

Recently, sensors using the magneto-impedance effect have been developed as magnetic sensors. Sensors using this magneto-impedance effect are smaller, more sensitive, have higher spatial resolution, and faster response than Hall sensors, magnetoresistive elements, fluxgate sensors, etc., and a magnetic detection method using this sensor has been proposed. (Patent Document 1).
JP 2000-258402 A

It has also been reported that a defect inside a steel plate is detected by a leakage magnetic flux flaw detection test method using a magneto-impedance effect type sensor (Non-Patent Document 1).
Koji Fujimoto, Yoshio Mohri, MAG-98-86, p39-43

  This inspection method uses the high-sensitivity magnetic field detection performance of the magneto-impedance effect type sensor, and it is necessary to apply a magnetic field to the object to be inspected, which is inappropriate for work at a high place.

By the way, according to the results of intensive studies by the present inventors, it has been confirmed that the defect of the object to be inspected can be detected with sufficient accuracy even by scanning the iron-based object to be inspected with a magneto-impedance effect type sensor without magnetizing. It was done.
In this way, unlike the magnetic flux leakage testing method, the defect can be detected without being magnetized. The bias magnetic field applied to the magneto-impedance effect element is bypassed to the iron-based object to be inspected and the defect of the object to be inspected. It is involved that the sensor output is changed by changing the bias magnetic field due to the change in reluctance of the object to be inspected.

  An object of the present invention is to provide an iron-based structure deterioration diagnosis apparatus capable of easily inspecting defects such as corrosion on the inner surface of an iron-based structure from the outer surface of the wall with sufficient accuracy.

According to a first aspect of the present invention, there is provided an apparatus for diagnosing deterioration of an iron-based structure, comprising a magneto-impedance effect element provided with a bias magnetic field coil and a detection circuit for detecting the output of the element through a detection circuit. A defect detection apparatus for scanning an impedance effect element in a state of approaching, and having a flexible substrate portion wound by tightening to a degree that can be slid on an object to be inspected , and a magnetic impedance effect element on the flexible substrate portion And a bias magnetic field coil is mounted.
According to a second aspect of the present invention, there is provided an iron-based structure deterioration diagnosis device comprising a magneto-impedance effect element provided with a coil for a bias magnetic field and a detection circuit for detecting the output of the element through a detection circuit. It is a defect detection device that scans an impedance effect element in a close state, and has a flexible substrate portion wound by tightening so that it can slide on the inspection object , and the inspection substrate side of this flexible substrate portion A magneto-impedance effect element and a bias magnetic field coil are connected and supported at the ends.

A degradation diagnosis apparatus for an iron-based structure according to claim 3 includes a detection circuit for detecting a bias magnetic field coil attached to a magneto-impedance effect element and detecting the output of the element through a detection circuit, Is a defect detection device that scans in a state where the magneto-impedance effect element is in close proximity, and has a flexible board portion that is wound around the object to be inspected so as to be slidable. The magneto-impedance effect is applied to the flexible board. An element, a bias magnetic field coil, and a detection circuit are mounted.
According to a fourth aspect of the present invention, there is provided the iron structure deterioration diagnosis apparatus according to any one of the first to third aspects, wherein the object to be inspected is a pipe.

  The iron structure deterioration diagnosis device according to claim 5 is the iron structure deterioration diagnosis device according to any one of claims 1 to 4, wherein the output of the magneto-impedance effect element provided with the bias magnetic field coil is used as a detection circuit. A plurality of channels are provided to detect through, and a plurality of channels of magneto-impedance effect elements are arranged in parallel.

An iron-based structure deterioration diagnosis device according to claim 6 is the iron-based structure deterioration diagnosis device according to any one of claims 1 to 5, wherein a magneto-impedance effect element with a bias magnetic field coil is paired, and both elements The detection circuit is provided with a differential section for detecting a difference between detection signals of the detection circuit with respect to.
An iron-based structure deterioration diagnosis device according to claim 7 is the iron-based structure deterioration diagnosis device according to claim 5 or 6, further comprising means for wirelessly transmitting a detection signal of each channel. To do.

(1) An amorphous wire as a magneto-impedance effect element has an easily magnetizable outer shell in the circumferential direction, and when the circumferential magnetic field by the excitation current is shifted from the circumferential direction, the circumferential permeability μ _θ changes, impedance changes due to changes in resistance based on inductance and skin effect, and the output of the magneto-impedance effect element changes. Therefore, Fe ₂ O ₃ (red rust) and Fe ₃ O ₄ (black rust) are generated due to corrosion of the back surface of the iron-based wall, or are thinned due to abrasion, and the permeability of the portion changes. The magnetic field in the circumferential direction due to the excitation current of the magneto-impedance effect element being moved to the wall surface is shifted from the circumferential direction by the change in the permeability of the electromagnetic field in the vicinity of the magneto-impedance effect element due to corrosion and thinning of the wall back surface. The output of the magneto-impedance effect element is changed. Therefore, it is possible to determine the degree of corrosion / thinning on the back surface of the wall using the output change as corrosion / thinning information.
(2) With respect to the bias magnetic field generated by the bias magnetic field coil, the iron-based wall also becomes a part of the circuit of the magnetic field, and the strength of the bias magnetic field changes according to the degree of corrosion / thinning of the wall back surface. Since this bias magnetic field passes through the amorphous wire as the magneto-impedance effect element in the axial direction, the circumferential magnetic field due to the excitation current is shifted from the circumferential direction, and the degree of the shift is the degree of corrosion / thinning of the back surface of the wall. Depending on Therefore, the change in output of the magneto-impedance effect element correlates with the degree of corrosion / thinning on the back surface of the wall, and the degree of corrosion / thinning on the back surface of the wall can be determined from the change in output.
(3) Since the magneto-impedance effect element with the bias magnetic field coil is mounted on the flexible substrate part or protrudes from the tip of the flexible substrate part and is connected and supported, even if the object to be inspected is a pipe, the flexible substrate By winding the part with a winding that can slide on the pipe, scanning can be performed for different pipe diameters and tapering.
Even if there is an obstacle on the surface of the object to be inspected, for example, there is a pipe joint part, or the surface of the object to be inspected is an uneven surface, the flexibility and flexibility of the flexible substrate part Scanning can be performed and the proximity of the magneto-impedance effect element and the surface of the object to be inspected can be well maintained, so that the effects (1) and (2) can be ensured even when there are obstacles on the surface of the object to be inspected. .
(4) Since a plurality of magneto-impedance effect elements are arranged side by side and the deterioration diagnosis apparatus is scanned in the direction orthogonal to the arrangement direction, the number of scanning operations can be reduced, so that the number of work steps can be reduced.
(5) Even if the structure is multi-channel and the iron-based structure exists at a high place, the deterioration signal of the iron-based structure can be easily detected by transmitting the detection signal of each channel to the computer in a wireless manner.
By these (1) to (5), defects such as corrosion on the wall back surface of the iron-based structure can be easily inspected from the wall surface side with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a detection circuit for one channel of a deterioration diagnosis apparatus according to the present invention.
In FIG. 1, reference numeral 1 denotes a magneto-impedance effect element, which has a zero magnetostriction or a negative magnetostriction having an outer shell portion in which magnetic domains whose spontaneous magnetization directions are opposite to each other in the circumferential direction of the wire are alternately separated by domain walls. Amorphous alloy wire is used. The inductance voltage component in the output voltage between both ends of the wire generated when a high-frequency excitation current is passed through an amorphous magnetic wire having zero magnetostriction or negative magnetostriction is obtained by the circumferential magnetic flux generated in the cross section of the wire. This occurs due to the magnetization of the easily magnetizable outer shell in the circumferential direction. Therefore, the circumferential magnetic permeability mu _theta depends on the circumferential direction of magnetization of Dosotokara portion. Thus, when a signal magnetic field is applied in the axial direction of the amorphous wire being energized, the outer shell portion having the easily magnetizable property in the circumferential direction is obtained by synthesizing the circumferential magnetic flux and the signal magnetic field magnetic flux by the energization. direction of magnetic flux acting deviates from the circumferential direction, correspondingly hardly occur magnetization in the circumferential direction, the circumferential permeability mu _theta changes, the inductance voltage content will vary to. This fluctuation phenomenon is called a magnetic inductance effect, which can be said to be a phenomenon in which the high-frequency excitation current (carrier wave) is modulated by a signal magnetic field (signal wave). Further, when the frequency of the energization current is in the order of MHz, a high-frequency skin effect appears greatly, and the skin depth δ = (2ρ / wμ _θ ) ^1/2 (μ _θ is the circumferential permeability, ρ as described above. electrical resistivity, w is shows the angular frequency, respectively) is changed by mu _theta, so changed by this as μθ is the signal magnetic field, the resistance voltage of the in wire ends between the output voltage also varies with the signal magnetic field It becomes like this. This fluctuation phenomenon is called a magneto-impedance effect, which can be said to be a phenomenon in which the high-frequency excitation current (carrier wave) is modulated by a signal magnetic field (signal wave).

In FIG. 1, 2 is a high-frequency current source circuit for applying a high-frequency excitation current to the magneto-impedance effect element, 3 is a signal magnetic field (signal wave) acting in the axial direction of the magneto-impedance effect element, and the high-frequency excitation current (carrier wave). A detector circuit that demodulates the modulated modulated wave, 4 an amplifier circuit that amplifies the demodulated wave, 6 a negative feedback coil, and 7 a bias magnetic field coil.
For the magneto-impedance effect element 1, an amorphous ribbon, an amorphous sputtered film, or the like can be used in addition to an amorphous wire having zero magnetostriction or negative magnetostriction.

In the magneto-impedance effect element 1, as described above, the direction of the magnetic flux acting on the outer shell portion that is easily magnetized in the circumferential direction is obtained by combining the circumferential magnetic flux based on the excitation current and the axial magnetic flux due to the signal magnetic field. Since the circumferential permeability μ _θ is changed from the circumferential direction, the inductance is changed, and the impedance is changed by changing the skin depth of the high frequency skin effect of the circumferential permeability μ _θ . Therefore, it is also circumferentially displaced by the synthesized magnetic field by ± signal magnetic field phi becomes ± phi, the circumferential direction of the magnetic field reduction ratio cos (± phi) is unchanged, the degree of reduction in thus mu _theta is the direction of the signal magnetic field It is not changed by positive or negative. Therefore, the signal magnetic field-output characteristic is substantially symmetrical with respect to the y axis when the signal magnetic field is taken on the x axis and the output is taken on the y axis as shown in FIG. This signal magnetic field-output characteristic is non-linear. Non-linear characteristics are unstable and high-sensitivity measurement is difficult. Therefore, negative feedback is applied by a negative feedback coil to linearize the output characteristics as shown in FIG. In FIG. 2B, Δw is a linear range where the gain without negative feedback is very large and the gain is determined only by the feedback rate β. However, with this output characteristic, since the polarity of the signal magnetic field cannot be determined, a bias magnetic field is applied by the bias coil 7 so that the polarity can be determined as shown in FIG. That is, the characteristic of (b) in FIG. 2 is moved in the negative direction of the x-axis by the bias magnetic field -Hb as shown in (c) of FIG. 2, and the maximum detection range of the signal magnetic field is within the range of the single diagonal line region. -Hmax to + Hmax.
From FIG. 2C, it can be understood that the output when the signal magnetic field Hex is 0 is changed by the change ΔHb of the bias magnetic field.

  In FIG. 1, reference numeral 81 denotes an A / D conversion / modulation device that modulates a carrier wave of a predetermined frequency with a digitized signal obtained by digitizing a detection signal, 82 denotes a transmission unit that transmits in a wireless manner, and 83 denotes a reception unit. Examples of wireless systems that can be used include SS wireless, Bluetooth, wireless LAN, infrared, and the like, and wireless LAN is particularly preferable.

The magneto-impedance effect element 1 is an alloy of transition metal and non-metal having a non-metal composition of 10 to 30 atomic%, particularly an alloy of transition metal and non-metal, and the amount of non-metal accounts for 10 to 30 atomic%. The transition metal is Fe and Co and the nonmetal is B and Si, or the transition metal is Fe and the nonmetal is B and Si. For example, the composition Co _70.5 B ₁₅ can be used. Si ₁₀ Fe _{4.5 having} a length of 2000 μm to 6000 μm and an outer diameter of 30 μm to 50 μmφ can be used.

  In the above, a normal high frequency such as a continuous sine wave, a pulse wave, or a triangular wave can be used as the high frequency excitation current, and examples of the high frequency excitation current source include a Hartley oscillation circuit, a Colpitts oscillation circuit, a collector tuning oscillation circuit, and a base tuning oscillation. In addition to a normal oscillation circuit such as an oscillation circuit, a square wave generator that integrates the square wave output of a crystal oscillator through an integration circuit via a DC cut capacitor and amplifies the triangular wave of the integration output by an amplification circuit, and oscillates a COMS-IC The triangular wave generator etc. which were used as a part can be used.

As the above detection circuit, for example, a configuration in which a modulated wave is half-wave rectified by an operational amplifier circuit and this half-wave rectified wave is processed by a parallel RC circuit or an RC low-pass filter to obtain an envelope output of the half-wave rectified wave, A configuration in which the modulated wave is half-wave rectified by a diode and the half-wave rectified wave is processed by a parallel RC circuit or an RC low-pass filter to obtain an envelope output of the half-wave rectified wave can be used.
Further, it is possible to use tuning detection in which a signal wave is sampled by multiplying the modulated wave by a square wave having a frequency fs tuned to the modulated wave (frequency fs).
In the above embodiment, the detected magnetic field is extracted by demodulating the modulated wave. However, the present invention is not limited to this, and the high-frequency excitation current wave (carrier wave) modulated by the signal magnetic field (signal wave) acting on the magneto-impedance effect element. Any suitable detecting means can be used as long as it can detect the signal magnetic field.

The negative feedback coil and the bias magnetic field coil can be wound around a magneto-impedance effect element. Further, as shown in FIG. 3, a negative feedback coil and a bias magnetic field coil can be wound around an iron core constituting a magneto-impedance effect element and a loop magnetic circuit. 3 (a) is a side view showing an example of a magneto-impedance effect unit with an iron core coil, FIG. 3 (b) is a bottom view, and FIG. 3 (c) is a cross-sectional view of FIG. It is sectional drawing.
In FIG. 3, reference numeral 100 denotes a substrate chip, and for example, a ceramic plate can be used. Reference numeral 101 denotes an electrode provided on one side of the substrate piece, and includes a magneto-impedance effect element connecting projection 102. This electrode can be provided by printing and baking a conductive paste, for example, a silver paste. 1x is a magneto-impedance effect element connected between the protrusions 102 and 102 of the electrodes 101 and 101 by soldering or welding, and an amorphous wire, amorphous ribbon, sputtered film, or the like having zero or negative magnetostriction can be used as described above. 103 is a C-type iron core made of iron or ferrite, 6x is a negative feedback coil wound around the C-type iron core, 7x is a bias magnetic field coil, and the magneto-impedance effect element 1x and the C-type iron core 103 The both ends of the C-type iron core 103 are fixed to the other surface of the substrate piece 100 with an adhesive or the like so as to constitute a loop magnetic circuit. The iron core material may be a magnetic material having a small residual magnetic flux density. Examples thereof include permalloy, ferrite, iron, amorphous magnetic alloy, magnetic powder mixed plastic, and the like.

FIG. 4A is a circuit diagram of the deterioration diagnosis apparatus according to the present invention.
4A, C _{1 to} C _n are the channel detection systems described with reference to FIG. 1, 1 ₁ to 1 _n are magneto-impedance effect elements, and 7 _{1 to} 7 _n are bias magnetic fields for the respective magneto-impedance effect elements. Reference numerals 3 _{1 to} 3 _{n denote} detection circuits for the magneto-impedance effect elements, 4 ₁ to 4 _{n denote} amplification circuits, and 6 _{1 to} 6 _{n denote} negative feedback coils.
81 _{1 to} 81 _n are multi-channel A / D converters / modulators that digitize the detection signals of the respective channels and modulate the carrier waves of the frequencies of the respective channels with the respective digital signals, and 82 is a multi-channel that transmits the modulated signal wave in a wireless manner. A transmitter, 83 is a receiver, and 84 is a computer that demodulates the received wave and extracts a digital signal for analysis.

FIG. 4B is an external view of the deterioration diagnosis apparatus, and FIG. 4B is a cross-sectional view of FIG. 4B.
In FIG. 4B, P is a flexible substrate, and a predetermined conductor pattern is printed on a plastic film such as a polyester film. S is a high-rigidity substrate attached to the width end of the flexible substrate, and the substrate is divided into a flexible portion F and a rigid portion H. As this high-rigidity substrate, a ceramic plate, an epoxy / glass laminated plate, an aluminum plate, or the like can be used. 1u ₁ ~1u _n is a magnetic impedance effect unit with iron core coils shown in FIG. 3, it is mounted a number of several channels minutes in parallel with the longitudinal direction of the orientation edge of the flexible portion F. B is an IC circuit in which an exciting current source circuit, a detection circuit for all channels, and an amplifier circuit are integrated, and is mounted on the rigid body portion H. E is a battery such as a lithium ion battery as a + Vcc power source for the exciting current source circuit, a + Vcc power source for the bias magnetic field coil, and a + Vcc power source for the amplifier circuit, and is mounted on the rigid body H. A portable battery may be connected to the substrate via a flexible cord without being mounted on the substrate. 810 is a multi-channel A / D converter that digitizes the detection signal of each channel, and is mounted on the rigid part H. Reference numeral 820 denotes a multi-channel transmitter that modulates a carrier wave having a frequency of each channel with each digital signal and transmits it in a wireless manner, and is connected to the multi-channel A / D converter by a cable. A computer 834 receives and demodulates the modulated wave to extract and analyze the digital signal.
Fig. 4-3 (a) shows an external view of another embodiment of the deterioration diagnostic apparatus, and Fig. 4-3 (b) shows a cross-sectional view of Fig. 4-3 (b).
In FIG. 4-3, P is a flexible substrate, and a predetermined conductor pattern is printed on a plastic film such as a polyester film. S is a high-rigidity substrate attached to the width end of the flexible substrate, and the substrate is divided into a flexible portion F and a rigid portion H. As this high-rigidity substrate, a ceramic plate, an epoxy / glass laminated plate, an aluminum plate, or the like can be used. 1u ₁ ~1u _n is a magnetic impedance effect unit with iron core coils shown in FIG. 3, parallel longitudinal orientation edge which is facing the number of several channels minutes the specimen in the flexible portion F Are connected and supported by rigid conductor bars and pins p. e is an electrode for connecting the magnetic impedance effect unit of the conductor pattern of the flexible portion F. B is an IC circuit in which an exciting current source circuit, a detection circuit for all channels, and an amplifier circuit are integrated, and is mounted on the rigid body portion H. E is a battery such as a lithium ion battery as a + Vcc power source for the exciting current source circuit, a + Vcc power source for the bias magnetic field coil, and a + Vcc power source for the amplifier circuit, and is mounted on the rigid body H. A portable battery may be connected to the substrate via a flexible cord without being mounted on the substrate. 810 is a multi-channel A / D converter that digitizes the detection signal of each channel, and is mounted on the rigid part H. Reference numeral 820 denotes a multi-channel transmitter that modulates a carrier wave having a frequency of each channel with each digital signal and transmits it in a wireless manner, and is connected to the multi-channel A / D converter by a cable. A computer 834 receives and demodulates the modulated wave to extract and analyze the digital signal.

In order to perform the deterioration diagnosis of the iron-based structure, for example, the inner surface of the iron-based pipe by the deterioration diagnosis apparatus of the present invention, the degree to which the flexible substrate portion F of the deterioration diagnosis apparatus can slide on the pipe P as shown in FIG. wound in seaming a magnetic impedance effect unit pipe surface in the longitudinal direction 1u ₁ ~1u _n of the magneto-impedance effect element 11, ... continue to scan in. The mounting surface of the flexible board F may be directed to the pipe surface, or the opposite surface may be directed to the pipe surface.
Figure 5-2 flexible board portion F of the deterioration diagnosis apparatus as shown in winding so as to be slidable in the pipe P, and magnetic impedance effect unit 1u ₁ ~1u _n of the magneto-impedance effect element 11, pipes ... 1n It is also possible to bend the flexible substrate F so as to be perpendicular to the surface, and to scan the pipe surface with the magneto-impedance effect elements 11 in the longitudinal direction.
In these cases, the portion wound around the pipe is only the flexible substrate portion on which the magneto-impedance effect element is mounted, and since the IC circuit component is mounted on the rigid body portion and is not distorted, the IC circuit component can be safely held. .
In the deterioration diagnosis apparatus of FIG. 4, the flexible substrate F of the deterioration diagnosis apparatus is wound around the pipe P by winding so as to be slidable as shown in FIG. magneto-impedance effect element 11 of the unit _1u 1 _{~1u n,} continue to scan in ... 1n. Change this case, since the flexible substrate portion F is supporting the magneto-impedance effect unit 1u ₁ ~1u _n becomes skeleton, the position of the magneto-impedance effect unit 1u ₁ ~1u _n is with the deformation of the flexible substrate portion F has been magneto-impedance effect unit _1u 1 _{~1u n} is close to the pipe surface.

FIGS. 6A and 6B show the action state of the bias magnetic field during scanning in FIGS. 5A and 5B.
(1) In FIGS. 6A and 6B, 1x is a magneto-impedance effect element of the magneto-impedance effect unit with iron core coil shown in FIG. 3, 103 is an iron core, 7x is a coil for bias magnetic field, G denotes an iron-based wall to be inspected, and since the wall to be inspected G is a magnetic body, a bias magnetic field bypasses the wall to be inspected G, and a magnetic change based on deterioration of the inner surface of the wall to be inspected, that is, reluctance Due to the change, the intensity of the bias magnetic field is changed.
Thus, in FIG. 2C, as indicated by the alternate long and short dash line, the output characteristics are shifted in accordance with the change ΔHb in the bias magnetic field, so that the detection output changes even when the external magnetic field Hex is zero.
(2) As described above, the magnetic field generated when an exciting current is passed through an amorphous wire as a magneto-impedance effect element changes according to the permeability of the electromagnetic field, and the electromagnetic field near the magneto-impedance effect element that is the magnetic field generation source When the magnetic permeability changes locally, the change in the magnetic field at that point spreads to the magnetic field inside the magneto-impedance effect element due to the continuity of the magnetic field, and the magnetic field in the magneto-impedance effect element is also distorted.
Therefore, the circumferential magnetic field in the magneto-impedance effect element 1x generated by flowing the excitation current is distorted by the change in permeability of the near electromagnetic field based on the deterioration of the back wall near the magneto-impedance effect element, and the excitation current As a result, the magnetic field in the circumferential direction in the magneto-impedance effect element is shifted from the circumferential direction in accordance with the corrosion / thinning of the wall back surface. As a result, the carrier wave based on the excitation current is modulated with information corresponding to the deterioration of the wall back surface. Become.
In this way, a magneto-impedance effect sensor is applied along the surface of the iron-based wall by applying a bias magnetic field to the magneto-impedance effect element, applying an exciting current to the magneto-impedance effect element, and detecting the element end output as a sensor output. By moving it, a signal corresponding to the deterioration of the back surface of the wall can be generated.

  The curve (b) in Fig. 7 shows the output when the magneto-impedance effect element is moved at a speed of 10 cm / sec to the old iron plate surface where rust is generated on the back surface, and the curve (b) in Fig. 7 shows almost no rust. The output when moving the magneto-impedance effect element at a speed of 10 cm / second on the surface of a new iron plate that has not been performed is shown, and according to the present invention, it has been confirmed that the presence or absence and position of rust can be detected with sufficient accuracy. .

  In the present invention, a carrier wave having a frequency corresponding to a channel is modulated with a detection signal of each channel and transmitted to a computer in a wireless manner, a modulated wave of each channel is demodulated, and a signal of each channel is analyzed by the computer. It is possible to grasp the degree of degradation and the location of degradation.

  In the above-described degradation diagnosis apparatus, the direction of the magneto-impedance effect elements arranged in parallel is set as the scanning direction. However, it is possible to set the direction perpendicular to the scanning direction or an intermediate direction between these two directions.

  In the deterioration diagnosis apparatus according to the present invention, the defect portion is magnetized prior to the scanning by the magneto-impedance effect element, and the flexible of the other end of the parallel magneto-impedance effect element group is evaluated in order to evaluate the weight of the defect from the degree of the magnetization. A magnetizing coil can also be mounted on the substrate portion.

In the above embodiment, the flexible substrate portion on which the magneto-impedance effect element with the bias magnetic field coil is mounted is wound around the object to be inspected, but as shown in FIGS. 8-1 and 8-2, The flexible substrate portion F in which the tip portion of the flexible substrate portion F having the magneto-impedance effect unit mounted on the tip portion is pressed against the surface of the inspection object G by the bending reaction force of the flexible substrate portion F, or the magneto-impedance effect unit is connected and supported. The tip of the substrate is pressed against the surface of the inspection object G by the bending reaction force of the flexible substrate F, and the magneto-impedance effect elements 1 ₁ to 1 _{n of} the magneto-impedance effect unit are brought close to the surface of the inspection object G for scanning. It can also be made.

In the deterioration diagnosis apparatus according to the present invention, as shown in FIG. 9-1 (A) or (B), two magneto-impedance effect elements with a bias magnetic field coil for each channel are arranged at predetermined intervals. 1 _m1 , 1 _m2 (m = 1 to n), and as shown in FIG. 9-2, the outputs of the two magneto-impedance effect elements 1 _m1 and 1 _m2 (m = 1 to n) of each channel Each detection circuit 3 _m1 , 3 _m2 (m = 1 to n) is detected, the detection signal is amplified by a differential amplifier circuit 4 _m (m = 1 to n), and the amplified output is A / D of each channel. The conversion / modulator 81 _m (m = 1 to n) may be digitized and modulated, and the modulated wave may be transmitted by the transmitter 82. 9-2, 83 is a receiver, 84 is a computer that demodulates a received modulation wave and extracts and analyzes a digital signal, 6 _m (m = 1 to n) is a negative feedback coil of each channel, 7 _m and 7 _m (m = 1 to n) indicate the respective bias magnetic field coils of the magneto-impedance effect elements 1 _m1 and 1 _m2 (m = 1 to n) of each channel.
FIG. 9-3 shows a detection waveform in one channel when two elements 1 _m1 and 1 _m2 are arranged at a distance in the scanning direction, and scanning of the two magneto-impedance effect elements in that channel. If the interval in the direction is d and the scanning speed is v, the detection signal p ′ of the magneto-impedance effect element after scanning appears after time d / v from the detection signal p of the magneto-impedance effect element in front of the scan, and its polarity is p And reverse polarity. In this method, external magnetic field noise and internal noise can be canceled for differential.
Even if one of the two elements 1 _m1 and 1 _m2 (m = 1 to n) is disposed at a position where no signal is detected, the external magnetic field noise and the internal noise can be canceled for differential. .
For example, in the example shown in FIG. 9-4, the flexible substrate portion F of the deterioration diagnosis apparatus is wound around the pipe P so as to be slidable, and two magneto-impedance effect elements 1 _m1 , 1 _m2 (m = 1 to 2). n) is mounted so as to be bent by the flexible substrate portion F so as to be perpendicular to the pipe surface, and the element 1 _m2 (m = 1 to n) is disposed at a position where a defect of the pipe is not detected.
Also, two magneto-impedance effect elements are provided on one side of a common substrate chip, and each C-type iron core that forms a loop magnetic circuit with each of the magneto-impedance effect elements is provided on the other side of the substrate chip. A magneto-impedance effect element pair unit in which a negative feedback coil and a bias magnetic field coil are wound around a mold iron core can also be used.

  The deterioration diagnosis apparatus for an iron-based structure according to the present invention is not limited to the above embodiment, and the scanning width is occupied by a plurality of parallel magneto-impedance effect elements for multiple channels, and these magneto-impedance effects When the flexible substrate portion on which the element is mounted is wound around the object to be inspected or the tip of the flexible substrate portion is pressed against the surface of the object to be inspected, the above-mentioned all magneto-impedance effect element can be brought close to the surface of the object to be inspected. As long as the circuit portion is mounted on the substrate portion that is not deformed, it can be implemented with an appropriate configuration.

It is a circuit diagram which shows the 1 channel detection system of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the detection characteristic of a magneto-impedance effect element. It is drawing which shows the magneto-impedance effect unit with an iron core coil used in the deterioration diagnostic apparatus based on this invention. It is drawing which shows the circuit diagram of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the external appearance of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the external appearance of another Example of the deterioration diagnosis apparatus of the iron-type structure based on this invention. It is drawing which shows the scanning state of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the scanning state of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the scanning state of another Example of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the operation | movement mechanism of the deterioration diagnosis apparatus of the iron-type structure based on this invention in the scanning state of FIGS. It is drawing which shows the operation | movement mechanism of the deterioration diagnosis apparatus of the iron-type structure based on this invention in the scanning state of FIGS. It is drawing which shows the detection result of the rust of the iron plate by a magneto-impedance effect element. It is drawing which shows the scanning state different from the above of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the scanning state different from the above of the deterioration diagnosis apparatus of the iron-type structure which concerns on this invention. It is drawing which shows the principal part of the deterioration diagnosis apparatus of the iron-type structure of Claim 6. It is drawing which shows the electric circuit of the deterioration diagnosis apparatus of the iron-type structure of Claim 6. It is drawing which shows the detection waveform of the deterioration diagnosis apparatus of the iron-type structure of Claim 6. It is drawing which shows the principal part of another example of the deterioration diagnosis apparatus of the iron-type structure of Claim 6.

Explanation of symbols

C1-Cn Detection circuits 11-1n for one channel Magneto-impedance effect elements 71-7n Coil for bias magnetic field 811-81n A / D converter / modulator 82 Wireless transmitter 834 Computer F Flexible substrate portion H Rigid substrate portion G Covered Inspection

Claims (7)

A defect detection device that includes a detection circuit for detecting a bias magnetic field coil attached to a magneto-impedance effect element and passing the detection element through a detection circuit, and scanning the magneto-impedance effect element close to the surface to be inspected. A flexible board portion wound by tightening to a degree that can be slid on the object to be inspected, and a magneto-impedance effect element and a bias magnetic field coil mounted on the flexible board portion. Deterioration diagnosis device for iron-based structures. A defect detection device that includes a detection circuit for detecting a bias magnetic field coil attached to a magneto-impedance effect element and passing the detection element through a detection circuit, and scanning the magneto-impedance effect element close to the surface to be inspected. There is a flexible board portion wound by tightening to the extent that it can slide on the object to be inspected, and a magneto-impedance effect element and a bias magnetic field coil are connected and supported at the inspected object side end of this flexible board portion. Deterioration diagnosis device for iron-based structures characterized by Defect detection in which a bias magnetic field coil is attached to a magneto-impedance effect element and a detection circuit that detects the output of the element through a detection circuit is detected, and scanning is performed with the magneto-impedance effect element approaching the surface to be inspected. The apparatus has a flexible substrate portion wound by tightening to a degree that can be slid on the object to be inspected , and a magneto-impedance effect element, a bias magnetic field coil, and a detection circuit are mounted on the flexible substrate. An iron structure deterioration diagnosis device characterized by The deterioration diagnosis apparatus for an iron-based structure according to any one of claims 1 to 3, wherein the object to be inspected is a pipe. 5. The magnetic impedance effect element according to claim 1, further comprising a plurality of channels for detecting the output of the magneto-impedance effect element provided with a bias magnetic field coil through a detection circuit, wherein the multi-channel magneto-impedance effect elements are arranged in parallel. Deterioration diagnosis apparatus for iron-based structures as described. The magneto-impedance effect element with a coil for bias magnetic field is made into a pair, and the differential part which detects the difference of the detection signal of the detection circuit with respect to both elements of the pair is provided in the detection circuit. 5. The deterioration diagnosis apparatus for iron-based structures according to any one of 5 above. 7. The deterioration diagnosis apparatus for an iron-based structure according to claim 5, further comprising means for wirelessly transmitting a detection signal of each channel.

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