JP2019082369A - Corrosion diagnostic method and corrosion diagnostic device - Google Patents

Abstract

To provide a corrosion diagnostic method and corrosion diagnostic device for increasing the accuracy of the corrosion diagnosis of an electric wire.SOLUTION: An exciting coil 11 and a detection coil 12 are disposed on an electric wire so that the central axis is along the radial direction of the electric wire 2. The exciting coil 11 and detection coil 12 are moved along a circumferential direction Y1 and a longitudinal direction Y2 of the electric wire 2. Thus, the exciting coil 11 and detection coil 12 are disposed at a plurality of different points on the electric wire 2. A control unit 17 integrates the outputs of the detection coil 12 detected at the plurality of different points, and diagnoses the corrosion state of the electric wire 2 on the basis of the integration value.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a corrosion diagnostic method and a corrosion diagnostic device.

  As a conventional corrosion diagnosis device, for example, a wire corrosion diagnosis device described in Patent Document 1 has been proposed. The wire corrosion diagnostic apparatus includes an eddy current flaw detection unit that detects an eddy current generated on the surface of the wire, and a storage unit that stores corrosion data indicating a relationship between the eddy current and the degree of corrosion of the wire. The wire corrosion diagnostic apparatus moves the eddy current flaw detection portion along the longitudinal direction of the wire, and determines the degree of corrosion based on comparison of the eddy current detected for each position and the corrosion data.

  In general, in the eddy current damage method, an alternating current is caused to flow through an exciting coil to induce an eddy current on the surface of a wire, and a magnetic flux change due to the eddy current is detected as an eddy current using a detection coil. Moreover, as for the existing electric wire, as shown to patent document 1, it is difficult to let an electric wire pass to a coil. Therefore, it is conceivable to superimpose the excitation coil and the detection coil on the electric wire such that the central axes of the excitation coil and the detection coil are along the radial direction of the electric wire to diagnose corrosion. For this reason, as shown in FIGS. 14-15, detection area A1 which can detect an eddy current becomes only a part of surface of an electric wire.

  By the way, the electric wire does not have a smooth surface but has a complex structure in which conductors are twisted together. The corrosion state of the wire conductor of such a stranded wire structure is as shown in FIG. 15, where corrosion F occurs unevenly, or as shown in FIG. There are various cases, such as when it is done, and it is uneven. For this reason, as described above, when a part of the surface of the electric wire is set as the detection area A1, there is a problem that it is difficult to make an accurate diagnosis of corrosion.

JP 2000-275165 A

  The present invention has been made in view of the above background, and an object of the present invention is to provide a corrosion diagnosis method and a corrosion diagnosis apparatus, which aim to improve the accuracy of corrosion diagnosis of a wire.

A corrosion diagnostic method according to an aspect of the present invention is a corrosion diagnostic method for diagnosing the corrosion state of a wire,
A detection step of arranging an excitation coil and a detection coil at different positions on the electric wire such that the central axis thereof is along the radial direction of the electric wire, and performing detection by the detection coil at the different positions;
An integrating step of integrating outputs of the detection coils detected at different positions on the wire;
And a diagnostic step of diagnosing a corrosion state of the electric wire based on the integrated value integrated in the integration step.

  In the detection step, detection may be performed at a plurality of different places in the circumferential direction on the electric wire.

  In the detection step, detection may be performed at a plurality of different points in the longitudinal direction on the electric wire.

  In the integration step, a moving average of outputs of the detection coils sequentially detected in the longitudinal direction or the longitudinal direction of the electric wire may be calculated.

A corrosion diagnostic device according to an aspect of the present invention is a corrosion diagnostic device for diagnosing corrosion of an electric wire,
Excitation coils and detection coils disposed at different positions on the electric wire such that the central axis is along the radial direction of the electric wire;
And an integrating unit configured to integrate the outputs of the detection coils detected at the plurality of different points.

A body portion attached to the wire and movable along the longitudinal direction of the wire;
A rotating unit attached to the main body and movable along the circumferential direction of the electric wire;
The excitation coil and the detection coil may be disposed in the rotating portion.

  As described above, according to the aspect, the accuracy of the corrosion diagnosis of the wire can be improved by accumulating the excitation coil and the detection coil at different places on the wire and integrating the output of the detection coil.

It is a block diagram which shows one Embodiment of the corrosion diagnostic apparatus which implemented the corrosion diagnostic method of this invention. It is a block diagram which shows the structure of the coil moving part which comprises the corrosion diagnostic apparatus shown in FIG. It is a front view which shows arrangement | positioning with a wire and the detection coil which comprises the corrosion diagnostic apparatus shown in FIG. It is a side view which shows arrangement | positioning with a wire and the detection coil which comprises the corrosion diagnostic apparatus shown in FIG. It is a flowchart which shows the process sequence of the control part of the corrosion diagnostic apparatus shown in FIG. It is an explanatory view for explaining a detection position of an eddy current. It is a figure which shows a mode that the detection coil shown in FIG. 1 is moved to the circumferential direction of an electric wire. It is a figure which shows the corrosion distribution for every detection area of a wire. The graph which shows the frequency characteristic of the output of the detection coil at the time of diagnosing about the electric wire of a reference sample and samples AG using a conventional product. It is a frequency characteristic of the difference of the output of the detection coil with respect to sample AG shown in FIG. 9, and the output of the detection coil with respect to a reference | standard sample. It is a graph which shows the frequency characteristic of the integrated value of the output of the detection coil 12 at the time of diagnosing about the electric wire 2 of a reference | standard sample and sample AG using this invention goods. It is a frequency characteristic of the difference of the integration value of the output of detection coil 12 to samples A to G shown in FIG. 11 and the integration value of the output of detection coil 12 to a reference sample. It is a front view which shows arrangement | positioning with the electric wire and the detection coil which comprises the corrosion diagnostic apparatus in 2nd Embodiment. It is the elements on larger scale of a sound wire conductor. It is the elements on larger scale of the wire conductor in which corrosion has arisen in part. It is the elements on larger scale of the wire conductor which corrosion has arisen between strands.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described based on FIGS. 1 to 4. The corrosion diagnosis device 1 shown in the figure is a device for diagnosing corrosion of the conductor of the electric wire 2. The electric wire 2 is provided with the conductor 22 which twisted the several strand 21 together, and the coating | coated part 23 which covers this conductor 22, as shown in FIG.

  The corrosion diagnostic apparatus 1 includes an excitation coil 11, a detection coil 12, an AC power supply 13, a detection unit 14, a coil moving unit 15, a display unit 16, and a control unit 17.

  The excitation coil 11 and the detection coil 12 are each configured by winding a winding in a spiral, for example. The exciting coil 11 is a coil for flowing an alternating current to induce an eddy current on the surface of the wire. The detection coil 12 is a coil through which an induced current flows due to a change in magnetic flux due to an eddy current. The alternating current power supply 13 is a power supply that causes an alternating current to flow through the exciting coil 11. The detection unit 14 detects an induced current flowing in the detection coil 12. The detection unit 14 detects an induced current flowing through the detection coil 12 as an eddy current.

  The coil moving unit 15 moves the excitation coil 11 and the detection coil 12 in the circumferential direction Y1 and the longitudinal direction Y2 of the electric wire 2. The coil moving unit 15 includes a main body 151 shown in FIG. 2, a rotating unit 152, a longitudinal motor 153 shown in FIG. 1, and a circumferential motor 154.

  As shown in FIG. 2, the main body 151 is formed in, for example, a cylindrical shape in which a slit (not shown) is formed on the side surface. The electric wire 2 is inserted into the main body 151 from a slit (not shown). Thereby, the electric wire 2 is passed through the cylinder of the main body 151. A rotating body such as a traveling roller is provided inside the main body portion 151, for example, and is movable along the longitudinal direction Y2 of the electric wire 2.

  The rotating portion 152 is formed in a cylindrical shape in which a slit (not shown) is formed on the side surface, and the main body portion 151 is inserted in the cylinder. The electric wire 2 is inserted into a cylindrical shape from a slit (not shown). The rotating portion 152 is provided with a rotating body such as, for example, a traveling roller inside thereof, and is movable along the circumferential direction Y1 of the electric wire 2 with respect to the main body portion 151.

  The excitation coil 11 and the detection coil 12 are attached to the rotating portion 152. As shown in FIG. 3 and FIG. 4, the detection coil 12 is attached to the rotating portion 152 so that the central axis thereof is along the radial direction of the electric wire 2. Although the exciting coil 11 is not shown in FIG. 3 and FIG. 4, the exciting coil 11 is disposed close to the detection coil 12 and, like the detection coil 12, the central axis thereof is along the radial direction of the electric wire 2. Are attached to the rotating portion 152.

  The longitudinal motor 153 is a motor that drives a rotating body provided in the main body 151 and drives the main body 151 in the longitudinal direction Y2. The circumferential direction motor 154 is a motor that drives the rotating body provided in the rotating portion 152 and drives the rotating portion 152 in the circumferential direction.

  The display unit 16 is for displaying the corrosion diagnosis result.

  The control unit 17 incorporates a CPU, a ROM, a RAM, and the like, and controls the entire corrosion diagnosis apparatus 1. The control unit 17 is connected to the AC power supply 13 and controls on / off of the AC power supply 13. The control unit 17 is connected to the motors 153 and 154, and rotates the detection coil 12 in the circumferential direction Y1 of the electric wire 2 or moves the detection coil 12 in the longitudinal direction Y2 by driving the motors 153 and 154. Thereby, the exciting coil 11 and the detecting coil 12 are arranged at different positions on the electric wire 2.

  The control unit 17 is connected to the detection unit 14, and the detection result of the detection unit 14 is input as an output of the detection coil 12. The control unit 17 functions as an integration unit, integrates the output of the detection coil 12 every time the detection coil 12 is moved, and diagnoses the corrosion of the electric wire 2 based on the integration value.

  Next, the operation of the corrosion diagnosis apparatus 1 outlined above will be described with reference to FIGS. First, as shown in FIG. 2, the diagnostician inserts the electric wire 2 into the main body portion 151 and the rotating portion 152. Thereby, the exciting coil 11 and the detection coil 12 can be arranged on the electric wire 2. Next, when the operation unit (not shown) is operated, the control unit 17 executes the detection process shown in FIG.

  First, the control unit 17 turns on the AC power supply 13 (step S1). As a result, an alternating current flows through the exciting coil 11 and an eddy current is induced on the conductor surface of the wire 2. Next, the control unit 17 takes in the output i of the detection unit 14, that is, the detection coil 12 (step S2). After integrating the output i taken into the integration value I (step S3), the control unit 17 drives the circumferential direction motor 154 to rotate the rotating unit 152 along the circumferential direction Y1 by a predetermined angle (step S4) ). Thereby, as shown in FIG. 7, the detection coil 12 is rotated by a predetermined angle in the circumferential direction Y1 of the electric wire 2.

  Next, after incrementing the number of rotations n1 (step S5), the control unit 17 determines whether the number of rotations n1 has reached N1 (step S6). N1 is preset to 360 ° / predetermined angle. For example, as shown in FIG. 6, when it is desired to move the detection coil 12 to ten locations along the circumferential direction Y1 of the electric wire 2, the predetermined angle is set to 36 ° and N1 is set to 10.

  If the number of rotations n1 has not reached N1 (N in step S6), the control unit 17 determines that the rotation is not 360 ° and returns to step S2 again. On the other hand, if the number of rotations n1 has reached N1 (Y in step S6), the control unit 17 resets the number of rotations n1 to 0 (step S7) and then drives the longitudinal motor 153 to set the main body 151 It is moved along the longitudinal direction Y2 by a distance (step S8). Thereafter, after incrementing the number of movements n2 (step S9), the control unit 17 determines whether or not the number of movements n2 has reached N2 (step S10). In the example shown in FIG. 6, N2 is set to 10.

  If the movement number n2 has not reached N2 (N in Step S10), the control unit 17 returns to Step S2 again. On the other hand, when the movement number n2 has reached N2 (Y in step S10), the control unit 17 performs corrosion diagnosis of the electric wire 2 based on the integrated value I (step S11). Specifically, the control unit 17 performs diagnosis by comparison with the integrated value of the output of the detection coil 12 detected by the normal wire 2.

  Thereafter, the control unit 17 displays the corrosion diagnosis result on the display unit 16 (step S12), and ends the process.

  According to the first embodiment described above, the excitation coil 11 and the detection coil 12 are overlapped at different points of the electric wire 2, and the corrosion diagnosis of the electric wire 2 is performed by the integrated value of the output of the detection coil 12. Although the difference between the output of the detection coil 12 at a point where the corrosion level is small and the output of the healthy wire 2 is small, the output difference becomes large by integrating it, and the diagnostic accuracy can be improved. . Further, when the corrosion state in each detection area A1 is a distribution as shown in FIG. 8, the corrosion as a whole of a plurality of detection areas A is diagnosed by diagnosing the corrosion based on the integrated value I. be able to.

  Next, in order to confirm the said effect, the inventors diagnosed about the electric wire 2 of a reference | standard sample and sample AG using the conventional item and this invention. The results are shown in FIGS. The conventional product is a device that arranges the detection coil 12 at one place of the electric wire 2 to make a diagnosis. Furthermore, the product of the present invention is a device that performs detection by arranging the detection coil 12 at ten different places of the electric wire 2. A reference | standard sample is the electric wire 2 which corrosion does not generate | occur | produce, and sample AG is the electric wire 2 from which a corrosion state differs, respectively.

  And FIG. 9 is a graph which shows the frequency characteristic of the output of the detection coil 12 at the time of diagnosing about the electric wire 2 of a reference sample and sample AG using a conventional product, and FIG. 10 is a sample A shown in FIG. It is a frequency characteristic of the difference of the output of detection coil 12 to G to the output of detection coil 12 to a reference sample.

  11 is a graph showing the frequency characteristic of the integrated value of the output of the detection coil 12 when diagnosing the wire 2 of the reference sample and the samples A to G using the product of the present invention, and FIG. It is a frequency characteristic of the difference of the integrated value of the output of detection coil 12 to samples A to G shown in and the integrated value of the output of detection coil 12 to a reference sample.

  As is clear from these figures, it was found that the product of the present invention can increase the difference in output from the reference sample by about 10 times compared to the conventional product, and that the accuracy can be improved accordingly.

  Further, according to the first embodiment described above, the excitation coil 11 and the detection coil 12 are arranged at a plurality of different places in the circumferential direction Y1 of the electric wire 2, and the outputs of the detection coil 12 at each place are integrated. This makes it possible to diagnose corrosion even if corrosion occurs partially in the circumferential direction.

  Further, according to the first embodiment described above, the excitation coil 11 and the detection coil 12 are arranged at a plurality of different positions in the longitudinal direction Y2 of the electric wire 2, and the outputs of the detection coil 12 at each position are integrated. Thereby, even if corrosion occurs partially in the longitudinal direction Y2, it can be diagnosed as corrosion.

  Further, according to the first embodiment described above, the main body 151 is provided movably along the longitudinal direction Y2 of the electric wire 2, the rotating portion 152 is attached to the main body 151, and the circumferential direction Y1 of the electric wire 2 is provided. The excitation coil 11 and the detection coil 12 are disposed on the rotating portion 152 so as to be movable. Thus, the coils 11 and 12 can be easily moved in the circumferential direction Y1 and the longitudinal direction Y2, and corrosion diagnosis can be performed using one coil 11 and 12.

  Further, according to the first embodiment described above, the coils 11 and 12 are disposed at different places in the circumferential direction Y1 and the longitudinal direction Y2. However, the coils 11 and 12 may be disposed at different points of the electric wire 2 and are not limited to the first embodiment.

  Moreover, according to the first embodiment described above, the main body 151 and the rotating part 152 are moved by the motors 153 and 154, but the present invention is not limited to this. The diagnostician may move the main body 151 and the rotation unit 152.

  Moreover, according to the first embodiment described above, the diagnosis result is displayed, but the present invention is not limited to this. Only the integrated value I may be displayed. A diagnostician can diagnose corrosion by looking at the integrated value I.

Second Embodiment
Next, a corrosion diagnostic apparatus according to a second embodiment will be described with reference to FIG. In the first embodiment, one excitation coil 11 and one detection coil 12 are rotated in the circumferential direction Y1 and moved in the longitudinal direction Y2. However, the present invention is not limited to this. As shown in FIG. 13, a plurality of excitation coils 11 and detection coils 12 may be provided. As shown in the figure, the plurality of detection coils 12 are arranged side by side in the circumferential direction Y1 of the electric wire 2. This eliminates the need to rotate the coils 11 and 12.

  It is also conceivable to arrange a plurality of coils 11, 12 along the longitudinal direction Y2. In this way, there is no need to move the coils 11, 12 in the longitudinal direction.

  When the output of the detection coil 12 is taken in, the control unit 17 supplies an alternating current to the plurality of exciting coils 11 in order, and sequentially takes the output of the detection coil 12 corresponding to the exciting coil 11 in which the alternating current flows. Make it

  Further, according to the first and second embodiments described above, for example, as shown in FIG. 8, the control unit 17 integrates the outputs of the detection coil 12 when arranged in 21 detection areas A1 to A21. But it is not limited to this. The control unit 17 may calculate a moving average of the outputs of the detection coil 12 sequentially detected in the longitudinal direction Y2. Specifically, the control unit 17 calculates an average of the detection areas A1 to A3, A8 to A10, and A15 to A17, an average of the detection areas A2 to A4, A9 to A11, and A16 to A18. The control unit 17 may also calculate a moving average of the outputs of the detection coil 12 sequentially detected in the circumferential direction Y1.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Corrosion diagnostic apparatus 2 Electric wire 11 Excitation coil 12 Detection coil 17 Control part (integration part)
151 main part 152 rotating part Y1 circumferential direction Y2 longitudinal direction

Claims (6)

A corrosion diagnostic method for diagnosing the corrosion state of a wire, comprising:
A detection step of arranging an excitation coil and a detection coil at different positions on the electric wire such that the central axis thereof is along the radial direction of the electric wire, and performing detection by the detection coil at the different positions;
An integrating step of integrating outputs of the detection coils detected at different positions on the wire;
A diagnosis step of diagnosing the corrosion state of the electric wire based on the integrated value integrated in the integration step.   The corrosion detection method according to claim 1, wherein in the detection step, detection is performed at a plurality of different points in the circumferential direction on the electric wire.   The corrosion detection method according to claim 1 or 2, wherein in the detection step, detection is performed at a plurality of different points in the longitudinal direction on the electric wire.   The corrosion diagnostic method according to any one of claims 1 to 3, wherein the integrating step calculates a moving average of outputs of the detection coil sequentially detected in the longitudinal direction or the longitudinal direction of the electric wire. . A corrosion diagnostic device for diagnosing corrosion of a wire,
Excitation coils and detection coils disposed at different positions on the electric wire such that the central axis is along the radial direction of the electric wire;
A corrosion diagnostic device comprising: an integrating unit that integrates outputs of the detection coil detected at the plurality of different points. A body portion attached to the wire and movable along the longitudinal direction of the wire;
A rotating unit attached to the main body and movable along the circumferential direction of the electric wire;
The corrosion diagnosis device according to claim 5, wherein the excitation coil and the detection coil are disposed in the rotating portion.

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